move xmpp and p2p to webrtc
Create a copy of talk/xmpp and talk/p2p under webrtc/libjingle/xmpp and
webrtc/p2p. Also makes libjingle use those version instead of the one in the talk folder.

BUG=3379

Review URL: https://webrtc-codereview.appspot.com/26999004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@7549 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/p2p/OWNERS b/webrtc/p2p/OWNERS
new file mode 100644
index 0000000..1a24a6a
--- /dev/null
+++ b/webrtc/p2p/OWNERS
@@ -0,0 +1,13 @@
+henrika@webrtc.org
+henrike@webrtc.org
+henrikg@webrtc.org
+hta@webrtc.org
+jiayl@webrtc.org
+juberti@webrtc.org
+mflodman@webrtc.org
+perkj@webrtc.org
+pthatcher@webrtc.org
+sergeyu@chromium.org
+tommi@webrtc.org
+
+per-file BUILD.gn=kjellander@webrtc.org
diff --git a/webrtc/p2p/base/asyncstuntcpsocket.cc b/webrtc/p2p/base/asyncstuntcpsocket.cc
new file mode 100644
index 0000000..2b1b693
--- /dev/null
+++ b/webrtc/p2p/base/asyncstuntcpsocket.cc
@@ -0,0 +1,153 @@
+/*
+ *  Copyright 2013 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/asyncstuntcpsocket.h"
+
+#include <string.h>
+
+#include "webrtc/p2p/base/stun.h"
+#include "webrtc/base/common.h"
+#include "webrtc/base/logging.h"
+
+namespace cricket {
+
+static const size_t kMaxPacketSize = 64 * 1024;
+
+typedef uint16 PacketLength;
+static const size_t kPacketLenSize = sizeof(PacketLength);
+static const size_t kPacketLenOffset = 2;
+static const size_t kBufSize = kMaxPacketSize + kStunHeaderSize;
+static const size_t kTurnChannelDataHdrSize = 4;
+
+inline bool IsStunMessage(uint16 msg_type) {
+  // The first two bits of a channel data message are 0b01.
+  return (msg_type & 0xC000) ? false : true;
+}
+
+// AsyncStunTCPSocket
+// Binds and connects |socket| and creates AsyncTCPSocket for
+// it. Takes ownership of |socket|. Returns NULL if bind() or
+// connect() fail (|socket| is destroyed in that case).
+AsyncStunTCPSocket* AsyncStunTCPSocket::Create(
+    rtc::AsyncSocket* socket,
+    const rtc::SocketAddress& bind_address,
+    const rtc::SocketAddress& remote_address) {
+  return new AsyncStunTCPSocket(AsyncTCPSocketBase::ConnectSocket(
+      socket, bind_address, remote_address), false);
+}
+
+AsyncStunTCPSocket::AsyncStunTCPSocket(
+    rtc::AsyncSocket* socket, bool listen)
+    : rtc::AsyncTCPSocketBase(socket, listen, kBufSize) {
+}
+
+int AsyncStunTCPSocket::Send(const void *pv, size_t cb,
+                             const rtc::PacketOptions& options) {
+  if (cb > kBufSize || cb < kPacketLenSize + kPacketLenOffset) {
+    SetError(EMSGSIZE);
+    return -1;
+  }
+
+  // If we are blocking on send, then silently drop this packet
+  if (!IsOutBufferEmpty())
+    return static_cast<int>(cb);
+
+  int pad_bytes;
+  size_t expected_pkt_len = GetExpectedLength(pv, cb, &pad_bytes);
+
+  // Accepts only complete STUN/ChannelData packets.
+  if (cb != expected_pkt_len)
+    return -1;
+
+  AppendToOutBuffer(pv, cb);
+
+  ASSERT(pad_bytes < 4);
+  char padding[4] = {0};
+  AppendToOutBuffer(padding, pad_bytes);
+
+  int res = FlushOutBuffer();
+  if (res <= 0) {
+    // drop packet if we made no progress
+    ClearOutBuffer();
+    return res;
+  }
+
+  // We claim to have sent the whole thing, even if we only sent partial
+  return static_cast<int>(cb);
+}
+
+void AsyncStunTCPSocket::ProcessInput(char* data, size_t* len) {
+  rtc::SocketAddress remote_addr(GetRemoteAddress());
+  // STUN packet - First 4 bytes. Total header size is 20 bytes.
+  // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+  // |0 0|     STUN Message Type     |         Message Length        |
+  // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+  // TURN ChannelData
+  // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+  // |         Channel Number        |            Length             |
+  // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+  while (true) {
+    // We need at least 4 bytes to read the STUN or ChannelData packet length.
+    if (*len < kPacketLenOffset + kPacketLenSize)
+      return;
+
+    int pad_bytes;
+    size_t expected_pkt_len = GetExpectedLength(data, *len, &pad_bytes);
+    size_t actual_length = expected_pkt_len + pad_bytes;
+
+    if (*len < actual_length) {
+      return;
+    }
+
+    SignalReadPacket(this, data, expected_pkt_len, remote_addr,
+                     rtc::CreatePacketTime(0));
+
+    *len -= actual_length;
+    if (*len > 0) {
+      memmove(data, data + actual_length, *len);
+    }
+  }
+}
+
+void AsyncStunTCPSocket::HandleIncomingConnection(
+    rtc::AsyncSocket* socket) {
+  SignalNewConnection(this, new AsyncStunTCPSocket(socket, false));
+}
+
+size_t AsyncStunTCPSocket::GetExpectedLength(const void* data, size_t len,
+                                             int* pad_bytes) {
+  *pad_bytes = 0;
+  PacketLength pkt_len =
+      rtc::GetBE16(static_cast<const char*>(data) + kPacketLenOffset);
+  size_t expected_pkt_len;
+  uint16 msg_type = rtc::GetBE16(data);
+  if (IsStunMessage(msg_type)) {
+    // STUN message.
+    expected_pkt_len = kStunHeaderSize + pkt_len;
+  } else {
+    // TURN ChannelData message.
+    expected_pkt_len = kTurnChannelDataHdrSize + pkt_len;
+    // From RFC 5766 section 11.5
+    // Over TCP and TLS-over-TCP, the ChannelData message MUST be padded to
+    // a multiple of four bytes in order to ensure the alignment of
+    // subsequent messages.  The padding is not reflected in the length
+    // field of the ChannelData message, so the actual size of a ChannelData
+    // message (including padding) is (4 + Length) rounded up to the nearest
+    // multiple of 4.  Over UDP, the padding is not required but MAY be
+    // included.
+    if (expected_pkt_len % 4)
+      *pad_bytes = 4 - (expected_pkt_len % 4);
+  }
+  return expected_pkt_len;
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/asyncstuntcpsocket.h b/webrtc/p2p/base/asyncstuntcpsocket.h
new file mode 100644
index 0000000..4f53b03
--- /dev/null
+++ b/webrtc/p2p/base/asyncstuntcpsocket.h
@@ -0,0 +1,50 @@
+/*
+ *  Copyright 2013 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_ASYNCSTUNTCPSOCKET_H_
+#define WEBRTC_P2P_BASE_ASYNCSTUNTCPSOCKET_H_
+
+#include "webrtc/base/asynctcpsocket.h"
+#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/socketfactory.h"
+
+namespace cricket {
+
+class AsyncStunTCPSocket : public rtc::AsyncTCPSocketBase {
+ public:
+  // Binds and connects |socket| and creates AsyncTCPSocket for
+  // it. Takes ownership of |socket|. Returns NULL if bind() or
+  // connect() fail (|socket| is destroyed in that case).
+  static AsyncStunTCPSocket* Create(
+      rtc::AsyncSocket* socket,
+      const rtc::SocketAddress& bind_address,
+      const rtc::SocketAddress& remote_address);
+
+  AsyncStunTCPSocket(rtc::AsyncSocket* socket, bool listen);
+  virtual ~AsyncStunTCPSocket() {}
+
+  virtual int Send(const void* pv, size_t cb,
+                   const rtc::PacketOptions& options);
+  virtual void ProcessInput(char* data, size_t* len);
+  virtual void HandleIncomingConnection(rtc::AsyncSocket* socket);
+
+ private:
+  // This method returns the message hdr + length written in the header.
+  // This method also returns the number of padding bytes needed/added to the
+  // turn message. |pad_bytes| should be used only when |is_turn| is true.
+  size_t GetExpectedLength(const void* data, size_t len,
+                           int* pad_bytes);
+
+  DISALLOW_EVIL_CONSTRUCTORS(AsyncStunTCPSocket);
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_ASYNCSTUNTCPSOCKET_H_
diff --git a/webrtc/p2p/base/asyncstuntcpsocket_unittest.cc b/webrtc/p2p/base/asyncstuntcpsocket_unittest.cc
new file mode 100644
index 0000000..22c1b26
--- /dev/null
+++ b/webrtc/p2p/base/asyncstuntcpsocket_unittest.cc
@@ -0,0 +1,263 @@
+/*
+ *  Copyright 2013 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/asyncstuntcpsocket.h"
+#include "webrtc/base/asyncsocket.h"
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/physicalsocketserver.h"
+#include "webrtc/base/virtualsocketserver.h"
+
+namespace cricket {
+
+static unsigned char kStunMessageWithZeroLength[] = {
+  0x00, 0x01, 0x00, 0x00,  // length of 0 (last 2 bytes)
+  0x21, 0x12, 0xA4, 0x42,
+  '0', '1', '2', '3',
+  '4', '5', '6', '7',
+  '8', '9', 'a', 'b',
+};
+
+
+static unsigned char kTurnChannelDataMessageWithZeroLength[] = {
+  0x40, 0x00, 0x00, 0x00,  // length of 0 (last 2 bytes)
+};
+
+static unsigned char kTurnChannelDataMessage[] = {
+  0x40, 0x00, 0x00, 0x10,
+  0x21, 0x12, 0xA4, 0x42,
+  '0', '1', '2', '3',
+  '4', '5', '6', '7',
+  '8', '9', 'a', 'b',
+};
+
+static unsigned char kStunMessageWithInvalidLength[] = {
+  0x00, 0x01, 0x00, 0x10,
+  0x21, 0x12, 0xA4, 0x42,
+  '0', '1', '2', '3',
+  '4', '5', '6', '7',
+  '8', '9', 'a', 'b',
+};
+
+static unsigned char kTurnChannelDataMessageWithInvalidLength[] = {
+  0x80, 0x00, 0x00, 0x20,
+  0x21, 0x12, 0xA4, 0x42,
+  '0', '1', '2', '3',
+  '4', '5', '6', '7',
+  '8', '9', 'a', 'b',
+};
+
+static unsigned char kTurnChannelDataMessageWithOddLength[] = {
+  0x40, 0x00, 0x00, 0x05,
+  0x21, 0x12, 0xA4, 0x42,
+  '0',
+};
+
+
+static const rtc::SocketAddress kClientAddr("11.11.11.11", 0);
+static const rtc::SocketAddress kServerAddr("22.22.22.22", 0);
+
+class AsyncStunTCPSocketTest : public testing::Test,
+                               public sigslot::has_slots<> {
+ protected:
+  AsyncStunTCPSocketTest()
+      : vss_(new rtc::VirtualSocketServer(NULL)),
+        ss_scope_(vss_.get()) {
+  }
+
+  virtual void SetUp() {
+    CreateSockets();
+  }
+
+  void CreateSockets() {
+    rtc::AsyncSocket* server = vss_->CreateAsyncSocket(
+        kServerAddr.family(), SOCK_STREAM);
+    server->Bind(kServerAddr);
+    recv_socket_.reset(new AsyncStunTCPSocket(server, true));
+    recv_socket_->SignalNewConnection.connect(
+        this, &AsyncStunTCPSocketTest::OnNewConnection);
+
+    rtc::AsyncSocket* client = vss_->CreateAsyncSocket(
+        kClientAddr.family(), SOCK_STREAM);
+    send_socket_.reset(AsyncStunTCPSocket::Create(
+        client, kClientAddr, recv_socket_->GetLocalAddress()));
+    ASSERT_TRUE(send_socket_.get() != NULL);
+    vss_->ProcessMessagesUntilIdle();
+  }
+
+  void OnReadPacket(rtc::AsyncPacketSocket* socket, const char* data,
+                    size_t len, const rtc::SocketAddress& remote_addr,
+                    const rtc::PacketTime& packet_time) {
+    recv_packets_.push_back(std::string(data, len));
+  }
+
+  void OnNewConnection(rtc::AsyncPacketSocket* server,
+                       rtc::AsyncPacketSocket* new_socket) {
+    listen_socket_.reset(new_socket);
+    new_socket->SignalReadPacket.connect(
+        this, &AsyncStunTCPSocketTest::OnReadPacket);
+  }
+
+  bool Send(const void* data, size_t len) {
+    rtc::PacketOptions options;
+    size_t ret = send_socket_->Send(
+        reinterpret_cast<const char*>(data), len, options);
+    vss_->ProcessMessagesUntilIdle();
+    return (ret == len);
+  }
+
+  bool CheckData(const void* data, int len) {
+    bool ret = false;
+    if (recv_packets_.size()) {
+      std::string packet =  recv_packets_.front();
+      recv_packets_.pop_front();
+      ret = (memcmp(data, packet.c_str(), len) == 0);
+    }
+    return ret;
+  }
+
+  rtc::scoped_ptr<rtc::VirtualSocketServer> vss_;
+  rtc::SocketServerScope ss_scope_;
+  rtc::scoped_ptr<AsyncStunTCPSocket> send_socket_;
+  rtc::scoped_ptr<AsyncStunTCPSocket> recv_socket_;
+  rtc::scoped_ptr<rtc::AsyncPacketSocket> listen_socket_;
+  std::list<std::string> recv_packets_;
+};
+
+// Testing a stun packet sent/recv properly.
+TEST_F(AsyncStunTCPSocketTest, TestSingleStunPacket) {
+  EXPECT_TRUE(Send(kStunMessageWithZeroLength,
+                   sizeof(kStunMessageWithZeroLength)));
+  EXPECT_EQ(1u, recv_packets_.size());
+  EXPECT_TRUE(CheckData(kStunMessageWithZeroLength,
+                        sizeof(kStunMessageWithZeroLength)));
+}
+
+// Verify sending multiple packets.
+TEST_F(AsyncStunTCPSocketTest, TestMultipleStunPackets) {
+  EXPECT_TRUE(Send(kStunMessageWithZeroLength,
+                   sizeof(kStunMessageWithZeroLength)));
+  EXPECT_TRUE(Send(kStunMessageWithZeroLength,
+                   sizeof(kStunMessageWithZeroLength)));
+  EXPECT_TRUE(Send(kStunMessageWithZeroLength,
+                   sizeof(kStunMessageWithZeroLength)));
+  EXPECT_TRUE(Send(kStunMessageWithZeroLength,
+                   sizeof(kStunMessageWithZeroLength)));
+  EXPECT_EQ(4u, recv_packets_.size());
+}
+
+// Verifying TURN channel data message with zero length.
+TEST_F(AsyncStunTCPSocketTest, TestTurnChannelDataWithZeroLength) {
+  EXPECT_TRUE(Send(kTurnChannelDataMessageWithZeroLength,
+                   sizeof(kTurnChannelDataMessageWithZeroLength)));
+  EXPECT_EQ(1u, recv_packets_.size());
+  EXPECT_TRUE(CheckData(kTurnChannelDataMessageWithZeroLength,
+                        sizeof(kTurnChannelDataMessageWithZeroLength)));
+}
+
+// Verifying TURN channel data message.
+TEST_F(AsyncStunTCPSocketTest, TestTurnChannelData) {
+  EXPECT_TRUE(Send(kTurnChannelDataMessage,
+                   sizeof(kTurnChannelDataMessage)));
+  EXPECT_EQ(1u, recv_packets_.size());
+  EXPECT_TRUE(CheckData(kTurnChannelDataMessage,
+                        sizeof(kTurnChannelDataMessage)));
+}
+
+// Verifying TURN channel messages which needs padding handled properly.
+TEST_F(AsyncStunTCPSocketTest, TestTurnChannelDataPadding) {
+  EXPECT_TRUE(Send(kTurnChannelDataMessageWithOddLength,
+                   sizeof(kTurnChannelDataMessageWithOddLength)));
+  EXPECT_EQ(1u, recv_packets_.size());
+  EXPECT_TRUE(CheckData(kTurnChannelDataMessageWithOddLength,
+                        sizeof(kTurnChannelDataMessageWithOddLength)));
+}
+
+// Verifying stun message with invalid length.
+TEST_F(AsyncStunTCPSocketTest, TestStunInvalidLength) {
+  EXPECT_FALSE(Send(kStunMessageWithInvalidLength,
+                    sizeof(kStunMessageWithInvalidLength)));
+  EXPECT_EQ(0u, recv_packets_.size());
+
+  // Modify the message length to larger value.
+  kStunMessageWithInvalidLength[2] = 0xFF;
+  kStunMessageWithInvalidLength[3] = 0xFF;
+  EXPECT_FALSE(Send(kStunMessageWithInvalidLength,
+                    sizeof(kStunMessageWithInvalidLength)));
+
+  // Modify the message length to smaller value.
+  kStunMessageWithInvalidLength[2] = 0x00;
+  kStunMessageWithInvalidLength[3] = 0x01;
+  EXPECT_FALSE(Send(kStunMessageWithInvalidLength,
+                    sizeof(kStunMessageWithInvalidLength)));
+}
+
+// Verifying TURN channel data message with invalid length.
+TEST_F(AsyncStunTCPSocketTest, TestTurnChannelDataWithInvalidLength) {
+  EXPECT_FALSE(Send(kTurnChannelDataMessageWithInvalidLength,
+                   sizeof(kTurnChannelDataMessageWithInvalidLength)));
+  // Modify the length to larger value.
+  kTurnChannelDataMessageWithInvalidLength[2] = 0xFF;
+  kTurnChannelDataMessageWithInvalidLength[3] = 0xF0;
+  EXPECT_FALSE(Send(kTurnChannelDataMessageWithInvalidLength,
+                   sizeof(kTurnChannelDataMessageWithInvalidLength)));
+
+  // Modify the length to smaller value.
+  kTurnChannelDataMessageWithInvalidLength[2] = 0x00;
+  kTurnChannelDataMessageWithInvalidLength[3] = 0x00;
+  EXPECT_FALSE(Send(kTurnChannelDataMessageWithInvalidLength,
+                   sizeof(kTurnChannelDataMessageWithInvalidLength)));
+}
+
+// Verifying a small buffer handled (dropped) properly. This will be
+// a common one for both stun and turn.
+TEST_F(AsyncStunTCPSocketTest, TestTooSmallMessageBuffer) {
+  char data[1];
+  EXPECT_FALSE(Send(data, sizeof(data)));
+}
+
+// Verifying a legal large turn message.
+TEST_F(AsyncStunTCPSocketTest, TestMaximumSizeTurnPacket) {
+  // We have problem in getting the SignalWriteEvent from the virtual socket
+  // server. So increasing the send buffer to 64k.
+  // TODO(mallinath) - Remove this setting after we fix vss issue.
+  vss_->set_send_buffer_capacity(64 * 1024);
+  unsigned char packet[65539];
+  packet[0] = 0x40;
+  packet[1] = 0x00;
+  packet[2] = 0xFF;
+  packet[3] = 0xFF;
+  EXPECT_TRUE(Send(packet, sizeof(packet)));
+}
+
+// Verifying a legal large stun message.
+TEST_F(AsyncStunTCPSocketTest, TestMaximumSizeStunPacket) {
+  // We have problem in getting the SignalWriteEvent from the virtual socket
+  // server. So increasing the send buffer to 64k.
+  // TODO(mallinath) - Remove this setting after we fix vss issue.
+  vss_->set_send_buffer_capacity(64 * 1024);
+  unsigned char packet[65552];
+  packet[0] = 0x00;
+  packet[1] = 0x01;
+  packet[2] = 0xFF;
+  packet[3] = 0xFC;
+  EXPECT_TRUE(Send(packet, sizeof(packet)));
+}
+
+// Investigate why WriteEvent is not signaled from VSS.
+TEST_F(AsyncStunTCPSocketTest, DISABLED_TestWithSmallSendBuffer) {
+  vss_->set_send_buffer_capacity(1);
+  Send(kTurnChannelDataMessageWithOddLength,
+       sizeof(kTurnChannelDataMessageWithOddLength));
+  EXPECT_EQ(1u, recv_packets_.size());
+  EXPECT_TRUE(CheckData(kTurnChannelDataMessageWithOddLength,
+                        sizeof(kTurnChannelDataMessageWithOddLength)));
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/basicpacketsocketfactory.cc b/webrtc/p2p/base/basicpacketsocketfactory.cc
new file mode 100644
index 0000000..06dfe76
--- /dev/null
+++ b/webrtc/p2p/base/basicpacketsocketfactory.cc
@@ -0,0 +1,204 @@
+/*
+ *  Copyright 2011 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/basicpacketsocketfactory.h"
+
+#include "webrtc/p2p/base/asyncstuntcpsocket.h"
+#include "webrtc/p2p/base/stun.h"
+#include "webrtc/base/asynctcpsocket.h"
+#include "webrtc/base/asyncudpsocket.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/nethelpers.h"
+#include "webrtc/base/physicalsocketserver.h"
+#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/socketadapters.h"
+#include "webrtc/base/ssladapter.h"
+#include "webrtc/base/thread.h"
+
+namespace rtc {
+
+BasicPacketSocketFactory::BasicPacketSocketFactory()
+    : thread_(Thread::Current()),
+      socket_factory_(NULL) {
+}
+
+BasicPacketSocketFactory::BasicPacketSocketFactory(Thread* thread)
+    : thread_(thread),
+      socket_factory_(NULL) {
+}
+
+BasicPacketSocketFactory::BasicPacketSocketFactory(
+    SocketFactory* socket_factory)
+    : thread_(NULL),
+      socket_factory_(socket_factory) {
+}
+
+BasicPacketSocketFactory::~BasicPacketSocketFactory() {
+}
+
+AsyncPacketSocket* BasicPacketSocketFactory::CreateUdpSocket(
+    const SocketAddress& address, int min_port, int max_port) {
+  // UDP sockets are simple.
+  rtc::AsyncSocket* socket =
+      socket_factory()->CreateAsyncSocket(
+          address.family(), SOCK_DGRAM);
+  if (!socket) {
+    return NULL;
+  }
+  if (BindSocket(socket, address, min_port, max_port) < 0) {
+    LOG(LS_ERROR) << "UDP bind failed with error "
+                    << socket->GetError();
+    delete socket;
+    return NULL;
+  }
+  return new rtc::AsyncUDPSocket(socket);
+}
+
+AsyncPacketSocket* BasicPacketSocketFactory::CreateServerTcpSocket(
+    const SocketAddress& local_address, int min_port, int max_port, int opts) {
+
+  // Fail if TLS is required.
+  if (opts & PacketSocketFactory::OPT_TLS) {
+    LOG(LS_ERROR) << "TLS support currently is not available.";
+    return NULL;
+  }
+
+  rtc::AsyncSocket* socket =
+      socket_factory()->CreateAsyncSocket(local_address.family(),
+                                          SOCK_STREAM);
+  if (!socket) {
+    return NULL;
+  }
+
+  if (BindSocket(socket, local_address, min_port, max_port) < 0) {
+    LOG(LS_ERROR) << "TCP bind failed with error "
+                  << socket->GetError();
+    delete socket;
+    return NULL;
+  }
+
+  // If using SSLTCP, wrap the TCP socket in a pseudo-SSL socket.
+  if (opts & PacketSocketFactory::OPT_SSLTCP) {
+    ASSERT(!(opts & PacketSocketFactory::OPT_TLS));
+    socket = new rtc::AsyncSSLSocket(socket);
+  }
+
+  // Set TCP_NODELAY (via OPT_NODELAY) for improved performance.
+  // See http://go/gtalktcpnodelayexperiment
+  socket->SetOption(rtc::Socket::OPT_NODELAY, 1);
+
+  if (opts & PacketSocketFactory::OPT_STUN)
+    return new cricket::AsyncStunTCPSocket(socket, true);
+
+  return new rtc::AsyncTCPSocket(socket, true);
+}
+
+AsyncPacketSocket* BasicPacketSocketFactory::CreateClientTcpSocket(
+    const SocketAddress& local_address, const SocketAddress& remote_address,
+    const ProxyInfo& proxy_info, const std::string& user_agent, int opts) {
+
+  rtc::AsyncSocket* socket =
+      socket_factory()->CreateAsyncSocket(local_address.family(), SOCK_STREAM);
+  if (!socket) {
+    return NULL;
+  }
+
+  if (BindSocket(socket, local_address, 0, 0) < 0) {
+    LOG(LS_ERROR) << "TCP bind failed with error "
+                  << socket->GetError();
+    delete socket;
+    return NULL;
+  }
+
+  // If using a proxy, wrap the socket in a proxy socket.
+  if (proxy_info.type == rtc::PROXY_SOCKS5) {
+    socket = new rtc::AsyncSocksProxySocket(
+        socket, proxy_info.address, proxy_info.username, proxy_info.password);
+  } else if (proxy_info.type == rtc::PROXY_HTTPS) {
+    socket = new rtc::AsyncHttpsProxySocket(
+        socket, user_agent, proxy_info.address,
+        proxy_info.username, proxy_info.password);
+  }
+
+  // If using TLS, wrap the socket in an SSL adapter.
+  if (opts & PacketSocketFactory::OPT_TLS) {
+    ASSERT(!(opts & PacketSocketFactory::OPT_SSLTCP));
+
+    rtc::SSLAdapter* ssl_adapter = rtc::SSLAdapter::Create(socket);
+    if (!ssl_adapter) {
+      return NULL;
+    }
+
+    socket = ssl_adapter;
+
+    if (ssl_adapter->StartSSL(remote_address.hostname().c_str(), false) != 0) {
+      delete ssl_adapter;
+      return NULL;
+    }
+
+  // If using SSLTCP, wrap the TCP socket in a pseudo-SSL socket.
+  } else if (opts & PacketSocketFactory::OPT_SSLTCP) {
+    ASSERT(!(opts & PacketSocketFactory::OPT_TLS));
+    socket = new rtc::AsyncSSLSocket(socket);
+  }
+
+  if (socket->Connect(remote_address) < 0) {
+    LOG(LS_ERROR) << "TCP connect failed with error "
+                  << socket->GetError();
+    delete socket;
+    return NULL;
+  }
+
+  // Finally, wrap that socket in a TCP or STUN TCP packet socket.
+  AsyncPacketSocket* tcp_socket;
+  if (opts & PacketSocketFactory::OPT_STUN) {
+    tcp_socket = new cricket::AsyncStunTCPSocket(socket, false);
+  } else {
+    tcp_socket = new rtc::AsyncTCPSocket(socket, false);
+  }
+
+  // Set TCP_NODELAY (via OPT_NODELAY) for improved performance.
+  // See http://go/gtalktcpnodelayexperiment
+  tcp_socket->SetOption(rtc::Socket::OPT_NODELAY, 1);
+
+  return tcp_socket;
+}
+
+AsyncResolverInterface* BasicPacketSocketFactory::CreateAsyncResolver() {
+  return new rtc::AsyncResolver();
+}
+
+int BasicPacketSocketFactory::BindSocket(
+    AsyncSocket* socket, const SocketAddress& local_address,
+    int min_port, int max_port) {
+  int ret = -1;
+  if (min_port == 0 && max_port == 0) {
+    // If there's no port range, let the OS pick a port for us.
+    ret = socket->Bind(local_address);
+  } else {
+    // Otherwise, try to find a port in the provided range.
+    for (int port = min_port; ret < 0 && port <= max_port; ++port) {
+      ret = socket->Bind(rtc::SocketAddress(local_address.ipaddr(),
+                                                  port));
+    }
+  }
+  return ret;
+}
+
+SocketFactory* BasicPacketSocketFactory::socket_factory() {
+  if (thread_) {
+    ASSERT(thread_ == Thread::Current());
+    return thread_->socketserver();
+  } else {
+    return socket_factory_;
+  }
+}
+
+}  // namespace rtc
diff --git a/webrtc/p2p/base/basicpacketsocketfactory.h b/webrtc/p2p/base/basicpacketsocketfactory.h
new file mode 100644
index 0000000..fb3a526
--- /dev/null
+++ b/webrtc/p2p/base/basicpacketsocketfactory.h
@@ -0,0 +1,51 @@
+/*
+ *  Copyright 2011 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_BASICPACKETSOCKETFACTORY_H_
+#define WEBRTC_P2P_BASE_BASICPACKETSOCKETFACTORY_H_
+
+#include "webrtc/p2p/base/packetsocketfactory.h"
+
+namespace rtc {
+
+class AsyncSocket;
+class SocketFactory;
+class Thread;
+
+class BasicPacketSocketFactory : public PacketSocketFactory {
+ public:
+  BasicPacketSocketFactory();
+  explicit BasicPacketSocketFactory(Thread* thread);
+  explicit BasicPacketSocketFactory(SocketFactory* socket_factory);
+  virtual ~BasicPacketSocketFactory();
+
+  virtual AsyncPacketSocket* CreateUdpSocket(
+      const SocketAddress& local_address, int min_port, int max_port);
+  virtual AsyncPacketSocket* CreateServerTcpSocket(
+      const SocketAddress& local_address, int min_port, int max_port, int opts);
+  virtual AsyncPacketSocket* CreateClientTcpSocket(
+      const SocketAddress& local_address, const SocketAddress& remote_address,
+      const ProxyInfo& proxy_info, const std::string& user_agent, int opts);
+
+  virtual AsyncResolverInterface* CreateAsyncResolver();
+
+ private:
+  int BindSocket(AsyncSocket* socket, const SocketAddress& local_address,
+                 int min_port, int max_port);
+
+  SocketFactory* socket_factory();
+
+  Thread* thread_;
+  SocketFactory* socket_factory_;
+};
+
+}  // namespace rtc
+
+#endif  // WEBRTC_P2P_BASE_BASICPACKETSOCKETFACTORY_H_
diff --git a/webrtc/p2p/base/candidate.h b/webrtc/p2p/base/candidate.h
new file mode 100644
index 0000000..72bc69e
--- /dev/null
+++ b/webrtc/p2p/base/candidate.h
@@ -0,0 +1,212 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_CANDIDATE_H_
+#define WEBRTC_P2P_BASE_CANDIDATE_H_
+
+#include <limits.h>
+#include <math.h>
+
+#include <iomanip>
+#include <sstream>
+#include <string>
+
+#include "webrtc/p2p/base/constants.h"
+#include "webrtc/base/basictypes.h"
+#include "webrtc/base/socketaddress.h"
+
+namespace cricket {
+
+// Candidate for ICE based connection discovery.
+
+class Candidate {
+ public:
+  // TODO: Match the ordering and param list as per RFC 5245
+  // candidate-attribute syntax. http://tools.ietf.org/html/rfc5245#section-15.1
+  Candidate() : component_(0), priority_(0), generation_(0) {}
+  Candidate(const std::string& id, int component, const std::string& protocol,
+            const rtc::SocketAddress& address, uint32 priority,
+            const std::string& username, const std::string& password,
+            const std::string& type, const std::string& network_name,
+            uint32 generation, const std::string& foundation)
+      : id_(id), component_(component), protocol_(protocol), address_(address),
+        priority_(priority), username_(username), password_(password),
+        type_(type), network_name_(network_name), generation_(generation),
+        foundation_(foundation) {
+  }
+
+  const std::string & id() const { return id_; }
+  void set_id(const std::string & id) { id_ = id; }
+
+  int component() const { return component_; }
+  void set_component(int component) { component_ = component; }
+
+  const std::string & protocol() const { return protocol_; }
+  void set_protocol(const std::string & protocol) { protocol_ = protocol; }
+
+  const rtc::SocketAddress & address() const { return address_; }
+  void set_address(const rtc::SocketAddress & address) {
+    address_ = address;
+  }
+
+  uint32 priority() const { return priority_; }
+  void set_priority(const uint32 priority) { priority_ = priority; }
+
+//  void set_type_preference(uint32 type_preference) {
+//    priority_ = GetPriority(type_preference);
+//  }
+
+  // Maps old preference (which was 0.0-1.0) to match priority (which
+  // is 0-2^32-1) to to match RFC 5245, section 4.1.2.1.  Also see
+  // https://docs.google.com/a/google.com/document/d/
+  // 1iNQDiwDKMh0NQOrCqbj3DKKRT0Dn5_5UJYhmZO-t7Uc/edit
+  float preference() const {
+    // The preference value is clamped to two decimal precision.
+    return static_cast<float>(((priority_ >> 24) * 100 / 127) / 100.0);
+  }
+
+  void set_preference(float preference) {
+    // Limiting priority to UINT_MAX when value exceeds uint32 max.
+    // This can happen for e.g. when preference = 3.
+    uint64 prio_val = static_cast<uint64>(preference * 127) << 24;
+    priority_ = static_cast<uint32>(
+      rtc::_min(prio_val, static_cast<uint64>(UINT_MAX)));
+  }
+
+  const std::string & username() const { return username_; }
+  void set_username(const std::string & username) { username_ = username; }
+
+  const std::string & password() const { return password_; }
+  void set_password(const std::string & password) { password_ = password; }
+
+  const std::string & type() const { return type_; }
+  void set_type(const std::string & type) { type_ = type; }
+
+  const std::string & network_name() const { return network_name_; }
+  void set_network_name(const std::string & network_name) {
+    network_name_ = network_name;
+  }
+
+  // Candidates in a new generation replace those in the old generation.
+  uint32 generation() const { return generation_; }
+  void set_generation(uint32 generation) { generation_ = generation; }
+  const std::string generation_str() const {
+    std::ostringstream ost;
+    ost << generation_;
+    return ost.str();
+  }
+  void set_generation_str(const std::string& str) {
+    std::istringstream ist(str);
+    ist >> generation_;
+  }
+
+  const std::string& foundation() const {
+    return foundation_;
+  }
+
+  void set_foundation(const std::string& foundation) {
+    foundation_ = foundation;
+  }
+
+  const rtc::SocketAddress & related_address() const {
+    return related_address_;
+  }
+  void set_related_address(
+      const rtc::SocketAddress & related_address) {
+    related_address_ = related_address;
+  }
+  const std::string& tcptype() const { return tcptype_; }
+  void set_tcptype(const std::string& tcptype){
+    tcptype_ = tcptype;
+  }
+
+  // Determines whether this candidate is equivalent to the given one.
+  bool IsEquivalent(const Candidate& c) const {
+    // We ignore the network name, since that is just debug information, and
+    // the priority, since that should be the same if the rest is (and it's
+    // a float so equality checking is always worrisome).
+    return (id_ == c.id_) &&
+           (component_ == c.component_) &&
+           (protocol_ == c.protocol_) &&
+           (address_ == c.address_) &&
+           (username_ == c.username_) &&
+           (password_ == c.password_) &&
+           (type_ == c.type_) &&
+           (generation_ == c.generation_) &&
+           (foundation_ == c.foundation_) &&
+           (related_address_ == c.related_address_);
+  }
+
+  std::string ToString() const {
+    return ToStringInternal(false);
+  }
+
+  std::string ToSensitiveString() const {
+    return ToStringInternal(true);
+  }
+
+  uint32 GetPriority(uint32 type_preference,
+                     int network_adapter_preference,
+                     int relay_preference) const {
+    // RFC 5245 - 4.1.2.1.
+    // priority = (2^24)*(type preference) +
+    //            (2^8)*(local preference) +
+    //            (2^0)*(256 - component ID)
+
+    // |local_preference| length is 2 bytes, 0-65535 inclusive.
+    // In our implemenation we will partion local_preference into
+    //              0                 1
+    //       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+    //      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    //      |  NIC Pref     |    Addr Pref  |
+    //      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    // NIC Type - Type of the network adapter e.g. 3G/Wifi/Wired.
+    // Addr Pref - Address preference value as per RFC 3484.
+    // local preference =  (NIC Type << 8 | Addr_Pref) - relay preference.
+
+    int addr_pref = IPAddressPrecedence(address_.ipaddr());
+    int local_preference = ((network_adapter_preference << 8) | addr_pref) +
+        relay_preference;
+
+    return (type_preference << 24) |
+           (local_preference << 8) |
+           (256 - component_);
+  }
+
+ private:
+  std::string ToStringInternal(bool sensitive) const {
+    std::ostringstream ost;
+    std::string address = sensitive ? address_.ToSensitiveString() :
+                                      address_.ToString();
+    ost << "Cand[" << foundation_ << ":" << component_ << ":"
+        << protocol_ << ":" << priority_ << ":"
+        << address << ":" << type_ << ":" << related_address_ << ":"
+        << username_ << ":" << password_ << "]";
+    return ost.str();
+  }
+
+  std::string id_;
+  int component_;
+  std::string protocol_;
+  rtc::SocketAddress address_;
+  uint32 priority_;
+  std::string username_;
+  std::string password_;
+  std::string type_;
+  std::string network_name_;
+  uint32 generation_;
+  std::string foundation_;
+  rtc::SocketAddress related_address_;
+  std::string tcptype_;
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_CANDIDATE_H_
diff --git a/webrtc/p2p/base/common.h b/webrtc/p2p/base/common.h
new file mode 100644
index 0000000..8a3178c
--- /dev/null
+++ b/webrtc/p2p/base/common.h
@@ -0,0 +1,20 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_COMMON_H_
+#define WEBRTC_P2P_BASE_COMMON_H_
+
+#include "webrtc/base/logging.h"
+
+// Common log description format for jingle messages
+#define LOG_J(sev, obj) LOG(sev) << "Jingle:" << obj->ToString() << ": "
+#define LOG_JV(sev, obj) LOG_V(sev) << "Jingle:" << obj->ToString() << ": "
+
+#endif  // WEBRTC_P2P_BASE_COMMON_H_
diff --git a/webrtc/p2p/base/constants.cc b/webrtc/p2p/base/constants.cc
new file mode 100644
index 0000000..84c9ea2
--- /dev/null
+++ b/webrtc/p2p/base/constants.cc
@@ -0,0 +1,257 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/constants.h"
+
+#include <string>
+
+#include "webrtc/libjingle/xmllite/qname.h"
+
+namespace cricket {
+
+const char NS_EMPTY[] = "";
+const char NS_JINGLE[] = "urn:xmpp:jingle:1";
+const char NS_JINGLE_DRAFT[] = "google:jingle";
+const char NS_GINGLE[] = "http://www.google.com/session";
+
+// actions (aka <session> or <jingle>)
+const buzz::StaticQName QN_ACTION = { NS_EMPTY, "action" };
+const char LN_INITIATOR[] = "initiator";
+const buzz::StaticQName QN_INITIATOR = { NS_EMPTY, LN_INITIATOR };
+const buzz::StaticQName QN_CREATOR = { NS_EMPTY, "creator" };
+
+const buzz::StaticQName QN_JINGLE = { NS_JINGLE, "jingle" };
+const buzz::StaticQName QN_JINGLE_CONTENT = { NS_JINGLE, "content" };
+const buzz::StaticQName QN_JINGLE_CONTENT_NAME = { NS_EMPTY, "name" };
+const buzz::StaticQName QN_JINGLE_CONTENT_MEDIA = { NS_EMPTY, "media" };
+const buzz::StaticQName QN_JINGLE_REASON = { NS_JINGLE, "reason" };
+const buzz::StaticQName QN_JINGLE_DRAFT_GROUP = { NS_JINGLE_DRAFT, "group" };
+const buzz::StaticQName QN_JINGLE_DRAFT_GROUP_TYPE = { NS_EMPTY, "type" };
+const char JINGLE_CONTENT_MEDIA_AUDIO[] = "audio";
+const char JINGLE_CONTENT_MEDIA_VIDEO[] = "video";
+const char JINGLE_CONTENT_MEDIA_DATA[] = "data";
+const char JINGLE_ACTION_SESSION_INITIATE[] = "session-initiate";
+const char JINGLE_ACTION_SESSION_INFO[] = "session-info";
+const char JINGLE_ACTION_SESSION_ACCEPT[] = "session-accept";
+const char JINGLE_ACTION_SESSION_TERMINATE[] = "session-terminate";
+const char JINGLE_ACTION_TRANSPORT_INFO[] = "transport-info";
+const char JINGLE_ACTION_TRANSPORT_ACCEPT[] = "transport-accept";
+const char JINGLE_ACTION_DESCRIPTION_INFO[] = "description-info";
+
+const buzz::StaticQName QN_GINGLE_SESSION = { NS_GINGLE, "session" };
+const char GINGLE_ACTION_INITIATE[] = "initiate";
+const char GINGLE_ACTION_INFO[] = "info";
+const char GINGLE_ACTION_ACCEPT[] = "accept";
+const char GINGLE_ACTION_REJECT[] = "reject";
+const char GINGLE_ACTION_TERMINATE[] = "terminate";
+const char GINGLE_ACTION_CANDIDATES[] = "candidates";
+const char GINGLE_ACTION_UPDATE[] = "update";
+
+const char LN_ERROR[] = "error";
+const buzz::StaticQName QN_GINGLE_REDIRECT = { NS_GINGLE, "redirect" };
+const char STR_REDIRECT_PREFIX[] = "xmpp:";
+
+// Session Contents (aka Gingle <session><description>
+//                   or Jingle <content><description>)
+const char LN_DESCRIPTION[] = "description";
+const char LN_PAYLOADTYPE[] = "payload-type";
+const buzz::StaticQName QN_ID = { NS_EMPTY, "id" };
+const buzz::StaticQName QN_SID = { NS_EMPTY, "sid" };
+const buzz::StaticQName QN_NAME = { NS_EMPTY, "name" };
+const buzz::StaticQName QN_CLOCKRATE = { NS_EMPTY, "clockrate" };
+const buzz::StaticQName QN_BITRATE = { NS_EMPTY, "bitrate" };
+const buzz::StaticQName QN_CHANNELS = { NS_EMPTY, "channels" };
+const buzz::StaticQName QN_WIDTH = { NS_EMPTY, "width" };
+const buzz::StaticQName QN_HEIGHT = { NS_EMPTY, "height" };
+const buzz::StaticQName QN_FRAMERATE = { NS_EMPTY, "framerate" };
+const char LN_NAME[] = "name";
+const char LN_VALUE[] = "value";
+const buzz::StaticQName QN_PAYLOADTYPE_PARAMETER_NAME = { NS_EMPTY, LN_NAME };
+const buzz::StaticQName QN_PAYLOADTYPE_PARAMETER_VALUE = { NS_EMPTY, LN_VALUE };
+const char PAYLOADTYPE_PARAMETER_BITRATE[] = "bitrate";
+const char PAYLOADTYPE_PARAMETER_HEIGHT[] = "height";
+const char PAYLOADTYPE_PARAMETER_WIDTH[] = "width";
+const char PAYLOADTYPE_PARAMETER_FRAMERATE[] = "framerate";
+const char LN_BANDWIDTH[] = "bandwidth";
+
+const char CN_AUDIO[] = "audio";
+const char CN_VIDEO[] = "video";
+const char CN_DATA[] = "data";
+const char CN_OTHER[] = "main";
+// other SDP related strings
+const char GROUP_TYPE_BUNDLE[] = "BUNDLE";
+
+const char NS_JINGLE_RTP[] = "urn:xmpp:jingle:apps:rtp:1";
+const buzz::StaticQName QN_JINGLE_RTP_CONTENT =
+    { NS_JINGLE_RTP, LN_DESCRIPTION };
+const buzz::StaticQName QN_SSRC = { NS_EMPTY, "ssrc" };
+const buzz::StaticQName QN_JINGLE_RTP_PAYLOADTYPE =
+    { NS_JINGLE_RTP, LN_PAYLOADTYPE };
+const buzz::StaticQName QN_JINGLE_RTP_BANDWIDTH =
+    { NS_JINGLE_RTP, LN_BANDWIDTH };
+const buzz::StaticQName QN_JINGLE_RTCP_MUX = { NS_JINGLE_RTP, "rtcp-mux" };
+const buzz::StaticQName QN_JINGLE_RTCP_FB = { NS_JINGLE_RTP, "rtcp-fb" };
+const buzz::StaticQName QN_SUBTYPE = { NS_EMPTY, "subtype" };
+const buzz::StaticQName QN_PARAMETER = { NS_JINGLE_RTP, "parameter" };
+const buzz::StaticQName QN_JINGLE_RTP_HDREXT =
+    { NS_JINGLE_RTP, "rtp-hdrext" };
+const buzz::StaticQName QN_URI = { NS_EMPTY, "uri" };
+
+const char NS_JINGLE_DRAFT_SCTP[] = "google:jingle:sctp";
+const buzz::StaticQName QN_JINGLE_DRAFT_SCTP_CONTENT =
+    { NS_JINGLE_DRAFT_SCTP, LN_DESCRIPTION };
+const buzz::StaticQName QN_JINGLE_DRAFT_SCTP_STREAM =
+    { NS_JINGLE_DRAFT_SCTP, "stream" };
+
+const char NS_GINGLE_AUDIO[] = "http://www.google.com/session/phone";
+const buzz::StaticQName QN_GINGLE_AUDIO_CONTENT =
+    { NS_GINGLE_AUDIO, LN_DESCRIPTION };
+const buzz::StaticQName QN_GINGLE_AUDIO_PAYLOADTYPE =
+    { NS_GINGLE_AUDIO, LN_PAYLOADTYPE };
+const buzz::StaticQName QN_GINGLE_AUDIO_SRCID = { NS_GINGLE_AUDIO, "src-id" };
+const char NS_GINGLE_VIDEO[] = "http://www.google.com/session/video";
+const buzz::StaticQName QN_GINGLE_VIDEO_CONTENT =
+    { NS_GINGLE_VIDEO, LN_DESCRIPTION };
+const buzz::StaticQName QN_GINGLE_VIDEO_PAYLOADTYPE =
+    { NS_GINGLE_VIDEO, LN_PAYLOADTYPE };
+const buzz::StaticQName QN_GINGLE_VIDEO_SRCID = { NS_GINGLE_VIDEO, "src-id" };
+const buzz::StaticQName QN_GINGLE_VIDEO_BANDWIDTH =
+    { NS_GINGLE_VIDEO, LN_BANDWIDTH };
+
+// Crypto support.
+const buzz::StaticQName QN_ENCRYPTION = { NS_JINGLE_RTP, "encryption" };
+const buzz::StaticQName QN_ENCRYPTION_REQUIRED = { NS_EMPTY, "required" };
+const buzz::StaticQName QN_CRYPTO = { NS_JINGLE_RTP, "crypto" };
+const buzz::StaticQName QN_GINGLE_AUDIO_CRYPTO_USAGE =
+    { NS_GINGLE_AUDIO, "usage" };
+const buzz::StaticQName QN_GINGLE_VIDEO_CRYPTO_USAGE =
+    { NS_GINGLE_VIDEO, "usage" };
+const buzz::StaticQName QN_CRYPTO_SUITE = { NS_EMPTY, "crypto-suite" };
+const buzz::StaticQName QN_CRYPTO_KEY_PARAMS = { NS_EMPTY, "key-params" };
+const buzz::StaticQName QN_CRYPTO_TAG = { NS_EMPTY, "tag" };
+const buzz::StaticQName QN_CRYPTO_SESSION_PARAMS =
+    { NS_EMPTY, "session-params" };
+
+// Transports and candidates.
+const char LN_TRANSPORT[] = "transport";
+const char LN_CANDIDATE[] = "candidate";
+const buzz::StaticQName QN_UFRAG = { cricket::NS_EMPTY, "ufrag" };
+const buzz::StaticQName QN_PWD = { cricket::NS_EMPTY, "pwd" };
+const buzz::StaticQName QN_COMPONENT = { cricket::NS_EMPTY, "component" };
+const buzz::StaticQName QN_IP = { cricket::NS_EMPTY, "ip" };
+const buzz::StaticQName QN_PORT = { cricket::NS_EMPTY, "port" };
+const buzz::StaticQName QN_NETWORK = { cricket::NS_EMPTY, "network" };
+const buzz::StaticQName QN_GENERATION = { cricket::NS_EMPTY, "generation" };
+const buzz::StaticQName QN_PRIORITY = { cricket::NS_EMPTY, "priority" };
+const buzz::StaticQName QN_PROTOCOL = { cricket::NS_EMPTY, "protocol" };
+const char ICE_CANDIDATE_TYPE_PEER_STUN[] = "prflx";
+const char ICE_CANDIDATE_TYPE_SERVER_STUN[] = "srflx";
+// Minimum ufrag length is 4 characters as per RFC5245. We chose 16 because
+// some internal systems expect username to be 16 bytes.
+const int ICE_UFRAG_LENGTH = 16;
+// Minimum password length of 22 characters as per RFC5245. We chose 24 because
+// some internal systems expect password to be multiple of 4.
+const int ICE_PWD_LENGTH = 24;
+const size_t ICE_UFRAG_MIN_LENGTH = 4;
+const size_t ICE_PWD_MIN_LENGTH = 22;
+const size_t ICE_UFRAG_MAX_LENGTH = 255;
+const size_t ICE_PWD_MAX_LENGTH = 256;
+// TODO: This is media-specific, so might belong
+// somewhere like media/base/constants.h
+const int ICE_CANDIDATE_COMPONENT_RTP = 1;
+const int ICE_CANDIDATE_COMPONENT_RTCP = 2;
+const int ICE_CANDIDATE_COMPONENT_DEFAULT = 1;
+
+const buzz::StaticQName QN_FINGERPRINT = { cricket::NS_EMPTY, "fingerprint" };
+const buzz::StaticQName QN_FINGERPRINT_ALGORITHM =
+    { cricket::NS_EMPTY, "algorithm" };
+const buzz::StaticQName QN_FINGERPRINT_DIGEST = { cricket::NS_EMPTY, "digest" };
+
+const char NS_JINGLE_ICE_UDP[] = "urn:xmpp:jingle:transports:ice-udp:1";
+
+const char ICE_OPTION_GICE[] = "google-ice";
+const char NS_GINGLE_P2P[] = "http://www.google.com/transport/p2p";
+const buzz::StaticQName QN_GINGLE_P2P_TRANSPORT =
+    { NS_GINGLE_P2P, LN_TRANSPORT };
+const buzz::StaticQName QN_GINGLE_P2P_CANDIDATE =
+    { NS_GINGLE_P2P, LN_CANDIDATE };
+const buzz::StaticQName QN_GINGLE_P2P_UNKNOWN_CHANNEL_NAME =
+    { NS_GINGLE_P2P, "unknown-channel-name" };
+const buzz::StaticQName QN_GINGLE_CANDIDATE = { NS_GINGLE, LN_CANDIDATE };
+const buzz::StaticQName QN_ADDRESS = { cricket::NS_EMPTY, "address" };
+const buzz::StaticQName QN_USERNAME = { cricket::NS_EMPTY, "username" };
+const buzz::StaticQName QN_PASSWORD = { cricket::NS_EMPTY, "password" };
+const buzz::StaticQName QN_PREFERENCE = { cricket::NS_EMPTY, "preference" };
+const char GICE_CHANNEL_NAME_RTP[] = "rtp";
+const char GICE_CHANNEL_NAME_RTCP[] = "rtcp";
+const char GICE_CHANNEL_NAME_VIDEO_RTP[] = "video_rtp";
+const char GICE_CHANNEL_NAME_VIDEO_RTCP[] = "video_rtcp";
+const char GICE_CHANNEL_NAME_DATA_RTP[] = "data_rtp";
+const char GICE_CHANNEL_NAME_DATA_RTCP[] = "data_rtcp";
+
+// terminate reasons and errors
+const char JINGLE_ERROR_BAD_REQUEST[] = "bad-request";
+const char JINGLE_ERROR_OUT_OF_ORDER[] = "out-of-order";
+const char JINGLE_ERROR_UNKNOWN_SESSION[] = "unknown-session";
+
+// Call terminate reasons from XEP-166
+const char STR_TERMINATE_DECLINE[] = "decline";
+const char STR_TERMINATE_SUCCESS[] = "success";
+const char STR_TERMINATE_ERROR[] = "general-error";
+const char STR_TERMINATE_INCOMPATIBLE_PARAMETERS[] = "incompatible-parameters";
+
+// Old terminate reasons used by cricket
+const char STR_TERMINATE_CALL_ENDED[] = "call-ended";
+const char STR_TERMINATE_RECIPIENT_UNAVAILABLE[] = "recipient-unavailable";
+const char STR_TERMINATE_RECIPIENT_BUSY[] = "recipient-busy";
+const char STR_TERMINATE_INSUFFICIENT_FUNDS[] = "insufficient-funds";
+const char STR_TERMINATE_NUMBER_MALFORMED[] = "number-malformed";
+const char STR_TERMINATE_NUMBER_DISALLOWED[] = "number-disallowed";
+const char STR_TERMINATE_PROTOCOL_ERROR[] = "protocol-error";
+const char STR_TERMINATE_INTERNAL_SERVER_ERROR[] = "internal-server-error";
+const char STR_TERMINATE_UNKNOWN_ERROR[] = "unknown-error";
+
+// Draft view and notify messages.
+const char STR_JINGLE_DRAFT_CONTENT_NAME_VIDEO[] = "video";
+const char STR_JINGLE_DRAFT_CONTENT_NAME_AUDIO[] = "audio";
+const buzz::StaticQName QN_NICK = { cricket::NS_EMPTY, "nick" };
+const buzz::StaticQName QN_TYPE = { cricket::NS_EMPTY, "type" };
+const buzz::StaticQName QN_JINGLE_DRAFT_VIEW = { NS_JINGLE_DRAFT, "view" };
+const char STR_JINGLE_DRAFT_VIEW_TYPE_NONE[] = "none";
+const char STR_JINGLE_DRAFT_VIEW_TYPE_STATIC[] = "static";
+const buzz::StaticQName QN_JINGLE_DRAFT_PARAMS = { NS_JINGLE_DRAFT, "params" };
+const buzz::StaticQName QN_JINGLE_DRAFT_STREAMS = { NS_JINGLE_DRAFT, "streams" };
+const buzz::StaticQName QN_JINGLE_DRAFT_STREAM = { NS_JINGLE_DRAFT, "stream" };
+const buzz::StaticQName QN_DISPLAY = { cricket::NS_EMPTY, "display" };
+const buzz::StaticQName QN_CNAME = { cricket::NS_EMPTY, "cname" };
+const buzz::StaticQName QN_JINGLE_DRAFT_SSRC = { NS_JINGLE_DRAFT, "ssrc" };
+const buzz::StaticQName QN_JINGLE_DRAFT_SSRC_GROUP =
+    { NS_JINGLE_DRAFT, "ssrc-group" };
+const buzz::StaticQName QN_SEMANTICS = { cricket::NS_EMPTY, "semantics" };
+const buzz::StaticQName QN_JINGLE_LEGACY_NOTIFY = { NS_JINGLE_DRAFT, "notify" };
+const buzz::StaticQName QN_JINGLE_LEGACY_SOURCE = { NS_JINGLE_DRAFT, "source" };
+
+const char NS_GINGLE_RAW[] = "http://www.google.com/transport/raw-udp";
+const buzz::StaticQName QN_GINGLE_RAW_TRANSPORT = { NS_GINGLE_RAW, "transport" };
+const buzz::StaticQName QN_GINGLE_RAW_CHANNEL = { NS_GINGLE_RAW, "channel" };
+
+// old stuff
+#ifdef FEATURE_ENABLE_VOICEMAIL
+const char NS_VOICEMAIL[] = "http://www.google.com/session/voicemail";
+const buzz::StaticQName QN_VOICEMAIL_REGARDING = { NS_VOICEMAIL, "regarding" };
+#endif
+
+// From RFC 4145, SDP setup attribute values.
+const char CONNECTIONROLE_ACTIVE_STR[] = "active";
+const char CONNECTIONROLE_PASSIVE_STR[] = "passive";
+const char CONNECTIONROLE_ACTPASS_STR[] = "actpass";
+const char CONNECTIONROLE_HOLDCONN_STR[] = "holdconn";
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/constants.h b/webrtc/p2p/base/constants.h
new file mode 100644
index 0000000..57423f5
--- /dev/null
+++ b/webrtc/p2p/base/constants.h
@@ -0,0 +1,259 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_CONSTANTS_H_
+#define WEBRTC_P2P_BASE_CONSTANTS_H_
+
+#include <string>
+#include "webrtc/libjingle/xmllite/qname.h"
+
+// This file contains constants related to signaling that are used in various
+// classes in this directory.
+
+namespace cricket {
+
+// NS_ == namespace
+// QN_ == buzz::QName (namespace + name)
+// LN_ == "local name" == QName::LocalPart()
+//   these are useful when you need to find a tag
+//   that has different namespaces (like <description> or <transport>)
+
+extern const char NS_EMPTY[];
+extern const char NS_JINGLE[];
+extern const char NS_JINGLE_DRAFT[];
+extern const char NS_GINGLE[];
+
+enum SignalingProtocol {
+  PROTOCOL_JINGLE,
+  PROTOCOL_GINGLE,
+  PROTOCOL_HYBRID,
+};
+
+// actions (aka Gingle <session> or Jingle <jingle>)
+extern const buzz::StaticQName QN_ACTION;
+extern const char LN_INITIATOR[];
+extern const buzz::StaticQName QN_INITIATOR;
+extern const buzz::StaticQName QN_CREATOR;
+
+extern const buzz::StaticQName QN_JINGLE;
+extern const buzz::StaticQName QN_JINGLE_CONTENT;
+extern const buzz::StaticQName QN_JINGLE_CONTENT_NAME;
+extern const buzz::StaticQName QN_JINGLE_CONTENT_MEDIA;
+extern const buzz::StaticQName QN_JINGLE_REASON;
+extern const buzz::StaticQName QN_JINGLE_DRAFT_GROUP;
+extern const buzz::StaticQName QN_JINGLE_DRAFT_GROUP_TYPE;
+extern const char JINGLE_CONTENT_MEDIA_AUDIO[];
+extern const char JINGLE_CONTENT_MEDIA_VIDEO[];
+extern const char JINGLE_CONTENT_MEDIA_DATA[];
+extern const char JINGLE_ACTION_SESSION_INITIATE[];
+extern const char JINGLE_ACTION_SESSION_INFO[];
+extern const char JINGLE_ACTION_SESSION_ACCEPT[];
+extern const char JINGLE_ACTION_SESSION_TERMINATE[];
+extern const char JINGLE_ACTION_TRANSPORT_INFO[];
+extern const char JINGLE_ACTION_TRANSPORT_ACCEPT[];
+extern const char JINGLE_ACTION_DESCRIPTION_INFO[];
+
+extern const buzz::StaticQName QN_GINGLE_SESSION;
+extern const char GINGLE_ACTION_INITIATE[];
+extern const char GINGLE_ACTION_INFO[];
+extern const char GINGLE_ACTION_ACCEPT[];
+extern const char GINGLE_ACTION_REJECT[];
+extern const char GINGLE_ACTION_TERMINATE[];
+extern const char GINGLE_ACTION_CANDIDATES[];
+extern const char GINGLE_ACTION_UPDATE[];
+
+extern const char LN_ERROR[];
+extern const buzz::StaticQName QN_GINGLE_REDIRECT;
+extern const char STR_REDIRECT_PREFIX[];
+
+// Session Contents (aka Gingle <session><description>
+//                   or Jingle <content><description>)
+extern const char LN_DESCRIPTION[];
+extern const char LN_PAYLOADTYPE[];
+extern const buzz::StaticQName QN_ID;
+extern const buzz::StaticQName QN_SID;
+extern const buzz::StaticQName QN_NAME;
+extern const buzz::StaticQName QN_CLOCKRATE;
+extern const buzz::StaticQName QN_BITRATE;
+extern const buzz::StaticQName QN_CHANNELS;
+extern const buzz::StaticQName QN_PARAMETER;
+extern const char LN_NAME[];
+extern const char LN_VALUE[];
+extern const buzz::StaticQName QN_PAYLOADTYPE_PARAMETER_NAME;
+extern const buzz::StaticQName QN_PAYLOADTYPE_PARAMETER_VALUE;
+extern const char PAYLOADTYPE_PARAMETER_BITRATE[];
+extern const char PAYLOADTYPE_PARAMETER_HEIGHT[];
+extern const char PAYLOADTYPE_PARAMETER_WIDTH[];
+extern const char PAYLOADTYPE_PARAMETER_FRAMERATE[];
+extern const char LN_BANDWIDTH[];
+
+// CN_ == "content name".  When we initiate a session, we choose the
+// name, and when we receive a Gingle session, we provide default
+// names (since Gingle has no content names).  But when we receive a
+// Jingle call, the content name can be anything, so don't rely on
+// these values being the same as the ones received.
+extern const char CN_AUDIO[];
+extern const char CN_VIDEO[];
+extern const char CN_DATA[];
+extern const char CN_OTHER[];
+// other SDP related strings
+// GN stands for group name
+extern const char GROUP_TYPE_BUNDLE[];
+
+extern const char NS_JINGLE_RTP[];
+extern const buzz::StaticQName QN_JINGLE_RTP_CONTENT;
+extern const buzz::StaticQName QN_SSRC;
+extern const buzz::StaticQName QN_JINGLE_RTP_PAYLOADTYPE;
+extern const buzz::StaticQName QN_JINGLE_RTP_BANDWIDTH;
+extern const buzz::StaticQName QN_JINGLE_RTCP_MUX;
+extern const buzz::StaticQName QN_JINGLE_RTCP_FB;
+extern const buzz::StaticQName QN_SUBTYPE;
+extern const buzz::StaticQName QN_JINGLE_RTP_HDREXT;
+extern const buzz::StaticQName QN_URI;
+
+extern const char NS_JINGLE_DRAFT_SCTP[];
+extern const buzz::StaticQName QN_JINGLE_DRAFT_SCTP_CONTENT;
+extern const buzz::StaticQName QN_JINGLE_DRAFT_SCTP_STREAM;
+
+extern const char NS_GINGLE_AUDIO[];
+extern const buzz::StaticQName QN_GINGLE_AUDIO_CONTENT;
+extern const buzz::StaticQName QN_GINGLE_AUDIO_PAYLOADTYPE;
+extern const buzz::StaticQName QN_GINGLE_AUDIO_SRCID;
+extern const char NS_GINGLE_VIDEO[];
+extern const buzz::StaticQName QN_GINGLE_VIDEO_CONTENT;
+extern const buzz::StaticQName QN_GINGLE_VIDEO_PAYLOADTYPE;
+extern const buzz::StaticQName QN_GINGLE_VIDEO_SRCID;
+extern const buzz::StaticQName QN_GINGLE_VIDEO_BANDWIDTH;
+
+// Crypto support.
+extern const buzz::StaticQName QN_ENCRYPTION;
+extern const buzz::StaticQName QN_ENCRYPTION_REQUIRED;
+extern const buzz::StaticQName QN_CRYPTO;
+extern const buzz::StaticQName QN_GINGLE_AUDIO_CRYPTO_USAGE;
+extern const buzz::StaticQName QN_GINGLE_VIDEO_CRYPTO_USAGE;
+extern const buzz::StaticQName QN_CRYPTO_SUITE;
+extern const buzz::StaticQName QN_CRYPTO_KEY_PARAMS;
+extern const buzz::StaticQName QN_CRYPTO_TAG;
+extern const buzz::StaticQName QN_CRYPTO_SESSION_PARAMS;
+
+// Transports and candidates.
+extern const char LN_TRANSPORT[];
+extern const char LN_CANDIDATE[];
+extern const buzz::StaticQName QN_JINGLE_P2P_TRANSPORT;
+extern const buzz::StaticQName QN_JINGLE_P2P_CANDIDATE;
+extern const buzz::StaticQName QN_UFRAG;
+extern const buzz::StaticQName QN_COMPONENT;
+extern const buzz::StaticQName QN_PWD;
+extern const buzz::StaticQName QN_IP;
+extern const buzz::StaticQName QN_PORT;
+extern const buzz::StaticQName QN_NETWORK;
+extern const buzz::StaticQName QN_GENERATION;
+extern const buzz::StaticQName QN_PRIORITY;
+extern const buzz::StaticQName QN_PROTOCOL;
+extern const char ICE_CANDIDATE_TYPE_PEER_STUN[];
+extern const char ICE_CANDIDATE_TYPE_SERVER_STUN[];
+extern const int ICE_UFRAG_LENGTH;
+extern const int ICE_PWD_LENGTH;
+extern const size_t ICE_UFRAG_MIN_LENGTH;
+extern const size_t ICE_PWD_MIN_LENGTH;
+extern const size_t ICE_UFRAG_MAX_LENGTH;
+extern const size_t ICE_PWD_MAX_LENGTH;
+extern const int ICE_CANDIDATE_COMPONENT_RTP;
+extern const int ICE_CANDIDATE_COMPONENT_RTCP;
+extern const int ICE_CANDIDATE_COMPONENT_DEFAULT;
+
+extern const buzz::StaticQName QN_FINGERPRINT;
+extern const buzz::StaticQName QN_FINGERPRINT_ALGORITHM;
+extern const buzz::StaticQName QN_FINGERPRINT_DIGEST;
+
+extern const char NS_JINGLE_ICE_UDP[];
+
+extern const char ICE_OPTION_GICE[];
+extern const char NS_GINGLE_P2P[];
+extern const buzz::StaticQName QN_GINGLE_P2P_TRANSPORT;
+extern const buzz::StaticQName QN_GINGLE_P2P_CANDIDATE;
+extern const buzz::StaticQName QN_GINGLE_P2P_UNKNOWN_CHANNEL_NAME;
+extern const buzz::StaticQName QN_GINGLE_CANDIDATE;
+extern const buzz::StaticQName QN_ADDRESS;
+extern const buzz::StaticQName QN_USERNAME;
+extern const buzz::StaticQName QN_PASSWORD;
+extern const buzz::StaticQName QN_PREFERENCE;
+extern const char GINGLE_CANDIDATE_TYPE_STUN[];
+extern const char GICE_CHANNEL_NAME_RTP[];
+extern const char GICE_CHANNEL_NAME_RTCP[];
+extern const char GICE_CHANNEL_NAME_VIDEO_RTP[];
+extern const char GICE_CHANNEL_NAME_VIDEO_RTCP[];
+extern const char GICE_CHANNEL_NAME_DATA_RTP[];
+extern const char GICE_CHANNEL_NAME_DATA_RTCP[];
+
+extern const char NS_GINGLE_RAW[];
+extern const buzz::StaticQName QN_GINGLE_RAW_TRANSPORT;
+extern const buzz::StaticQName QN_GINGLE_RAW_CHANNEL;
+
+// terminate reasons and errors: see http://xmpp.org/extensions/xep-0166.html
+extern const char JINGLE_ERROR_BAD_REQUEST[];  // like parse error
+// got transport-info before session-initiate, for example
+extern const char JINGLE_ERROR_OUT_OF_ORDER[];
+extern const char JINGLE_ERROR_UNKNOWN_SESSION[];
+
+// Call terminate reasons from XEP-166
+extern const char STR_TERMINATE_DECLINE[];  // polite reject
+extern const char STR_TERMINATE_SUCCESS[];  // polite hangup
+extern const char STR_TERMINATE_ERROR[];  // something bad happened
+extern const char STR_TERMINATE_INCOMPATIBLE_PARAMETERS[];  // no codecs?
+
+// Old terminate reasons used by cricket
+extern const char STR_TERMINATE_CALL_ENDED[];
+extern const char STR_TERMINATE_RECIPIENT_UNAVAILABLE[];
+extern const char STR_TERMINATE_RECIPIENT_BUSY[];
+extern const char STR_TERMINATE_INSUFFICIENT_FUNDS[];
+extern const char STR_TERMINATE_NUMBER_MALFORMED[];
+extern const char STR_TERMINATE_NUMBER_DISALLOWED[];
+extern const char STR_TERMINATE_PROTOCOL_ERROR[];
+extern const char STR_TERMINATE_INTERNAL_SERVER_ERROR[];
+extern const char STR_TERMINATE_UNKNOWN_ERROR[];
+
+// Draft view and notify messages.
+extern const char STR_JINGLE_DRAFT_CONTENT_NAME_VIDEO[];
+extern const char STR_JINGLE_DRAFT_CONTENT_NAME_AUDIO[];
+extern const buzz::StaticQName QN_NICK;
+extern const buzz::StaticQName QN_TYPE;
+extern const buzz::StaticQName QN_JINGLE_DRAFT_VIEW;
+extern const char STR_JINGLE_DRAFT_VIEW_TYPE_NONE[];
+extern const char STR_JINGLE_DRAFT_VIEW_TYPE_STATIC[];
+extern const buzz::StaticQName QN_JINGLE_DRAFT_PARAMS;
+extern const buzz::StaticQName QN_WIDTH;
+extern const buzz::StaticQName QN_HEIGHT;
+extern const buzz::StaticQName QN_FRAMERATE;
+extern const buzz::StaticQName QN_JINGLE_DRAFT_STREAM;
+extern const buzz::StaticQName QN_JINGLE_DRAFT_STREAMS;
+extern const buzz::StaticQName QN_DISPLAY;
+extern const buzz::StaticQName QN_CNAME;
+extern const buzz::StaticQName QN_JINGLE_DRAFT_SSRC;
+extern const buzz::StaticQName QN_JINGLE_DRAFT_SSRC_GROUP;
+extern const buzz::StaticQName QN_SEMANTICS;
+extern const buzz::StaticQName QN_JINGLE_LEGACY_NOTIFY;
+extern const buzz::StaticQName QN_JINGLE_LEGACY_SOURCE;
+
+// old stuff
+#ifdef FEATURE_ENABLE_VOICEMAIL
+extern const char NS_VOICEMAIL[];
+extern const buzz::StaticQName QN_VOICEMAIL_REGARDING;
+#endif
+
+// RFC 4145, SDP setup attribute values.
+extern const char CONNECTIONROLE_ACTIVE_STR[];
+extern const char CONNECTIONROLE_PASSIVE_STR[];
+extern const char CONNECTIONROLE_ACTPASS_STR[];
+extern const char CONNECTIONROLE_HOLDCONN_STR[];
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_CONSTANTS_H_
diff --git a/webrtc/p2p/base/dtlstransport.h b/webrtc/p2p/base/dtlstransport.h
new file mode 100644
index 0000000..bb80dc8
--- /dev/null
+++ b/webrtc/p2p/base/dtlstransport.h
@@ -0,0 +1,240 @@
+/*
+ *  Copyright 2012 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_DTLSTRANSPORT_H_
+#define WEBRTC_P2P_BASE_DTLSTRANSPORT_H_
+
+#include "webrtc/p2p/base/dtlstransportchannel.h"
+#include "webrtc/p2p/base/transport.h"
+
+namespace rtc {
+class SSLIdentity;
+}
+
+namespace cricket {
+
+class PortAllocator;
+
+// Base should be a descendant of cricket::Transport
+template<class Base>
+class DtlsTransport : public Base {
+ public:
+  DtlsTransport(rtc::Thread* signaling_thread,
+                rtc::Thread* worker_thread,
+                const std::string& content_name,
+                PortAllocator* allocator,
+                rtc::SSLIdentity* identity)
+      : Base(signaling_thread, worker_thread, content_name, allocator),
+        identity_(identity),
+        secure_role_(rtc::SSL_CLIENT) {
+  }
+
+  ~DtlsTransport() {
+    Base::DestroyAllChannels();
+  }
+  virtual void SetIdentity_w(rtc::SSLIdentity* identity) {
+    identity_ = identity;
+  }
+  virtual bool GetIdentity_w(rtc::SSLIdentity** identity) {
+    if (!identity_)
+      return false;
+
+    *identity = identity_->GetReference();
+    return true;
+  }
+
+  virtual bool ApplyLocalTransportDescription_w(TransportChannelImpl* channel,
+                                                std::string* error_desc) {
+    rtc::SSLFingerprint* local_fp =
+        Base::local_description()->identity_fingerprint.get();
+
+    if (local_fp) {
+      // Sanity check local fingerprint.
+      if (identity_) {
+        rtc::scoped_ptr<rtc::SSLFingerprint> local_fp_tmp(
+            rtc::SSLFingerprint::Create(local_fp->algorithm,
+                                              identity_));
+        ASSERT(local_fp_tmp.get() != NULL);
+        if (!(*local_fp_tmp == *local_fp)) {
+          std::ostringstream desc;
+          desc << "Local fingerprint does not match identity. Expected: ";
+          desc << local_fp_tmp->ToString();
+          desc << " Got: " << local_fp->ToString();
+          return BadTransportDescription(desc.str(), error_desc);
+        }
+      } else {
+        return BadTransportDescription(
+            "Local fingerprint provided but no identity available.",
+            error_desc);
+      }
+    } else {
+      identity_ = NULL;
+    }
+
+    if (!channel->SetLocalIdentity(identity_)) {
+      return BadTransportDescription("Failed to set local identity.",
+                                     error_desc);
+    }
+
+    // Apply the description in the base class.
+    return Base::ApplyLocalTransportDescription_w(channel, error_desc);
+  }
+
+  virtual bool NegotiateTransportDescription_w(ContentAction local_role,
+                                               std::string* error_desc) {
+    if (!Base::local_description() || !Base::remote_description()) {
+      const std::string msg = "Local and Remote description must be set before "
+                              "transport descriptions are negotiated";
+      return BadTransportDescription(msg, error_desc);
+    }
+
+    rtc::SSLFingerprint* local_fp =
+        Base::local_description()->identity_fingerprint.get();
+    rtc::SSLFingerprint* remote_fp =
+        Base::remote_description()->identity_fingerprint.get();
+
+    if (remote_fp && local_fp) {
+      remote_fingerprint_.reset(new rtc::SSLFingerprint(*remote_fp));
+
+      // From RFC 4145, section-4.1, The following are the values that the
+      // 'setup' attribute can take in an offer/answer exchange:
+      //       Offer      Answer
+      //      ________________
+      //      active     passive / holdconn
+      //      passive    active / holdconn
+      //      actpass    active / passive / holdconn
+      //      holdconn   holdconn
+      //
+      // Set the role that is most conformant with RFC 5763, Section 5, bullet 1
+      // The endpoint MUST use the setup attribute defined in [RFC4145].
+      // The endpoint that is the offerer MUST use the setup attribute
+      // value of setup:actpass and be prepared to receive a client_hello
+      // before it receives the answer.  The answerer MUST use either a
+      // setup attribute value of setup:active or setup:passive.  Note that
+      // if the answerer uses setup:passive, then the DTLS handshake will
+      // not begin until the answerer is received, which adds additional
+      // latency. setup:active allows the answer and the DTLS handshake to
+      // occur in parallel.  Thus, setup:active is RECOMMENDED.  Whichever
+      // party is active MUST initiate a DTLS handshake by sending a
+      // ClientHello over each flow (host/port quartet).
+      // IOW - actpass and passive modes should be treated as server and
+      // active as client.
+      ConnectionRole local_connection_role =
+          Base::local_description()->connection_role;
+      ConnectionRole remote_connection_role =
+          Base::remote_description()->connection_role;
+
+      bool is_remote_server = false;
+      if (local_role == CA_OFFER) {
+        if (local_connection_role != CONNECTIONROLE_ACTPASS) {
+          return BadTransportDescription(
+              "Offerer must use actpass value for setup attribute.",
+              error_desc);
+        }
+
+        if (remote_connection_role == CONNECTIONROLE_ACTIVE ||
+            remote_connection_role == CONNECTIONROLE_PASSIVE ||
+            remote_connection_role == CONNECTIONROLE_NONE) {
+          is_remote_server = (remote_connection_role == CONNECTIONROLE_PASSIVE);
+        } else {
+          const std::string msg =
+              "Answerer must use either active or passive value "
+              "for setup attribute.";
+          return BadTransportDescription(msg, error_desc);
+        }
+        // If remote is NONE or ACTIVE it will act as client.
+      } else {
+        if (remote_connection_role != CONNECTIONROLE_ACTPASS &&
+            remote_connection_role != CONNECTIONROLE_NONE) {
+          return BadTransportDescription(
+              "Offerer must use actpass value for setup attribute.",
+              error_desc);
+        }
+
+        if (local_connection_role == CONNECTIONROLE_ACTIVE ||
+            local_connection_role == CONNECTIONROLE_PASSIVE) {
+          is_remote_server = (local_connection_role == CONNECTIONROLE_ACTIVE);
+        } else {
+          const std::string msg =
+              "Answerer must use either active or passive value "
+              "for setup attribute.";
+          return BadTransportDescription(msg, error_desc);
+        }
+
+        // If local is passive, local will act as server.
+      }
+
+      secure_role_ = is_remote_server ? rtc::SSL_CLIENT :
+                                        rtc::SSL_SERVER;
+
+    } else if (local_fp && (local_role == CA_ANSWER)) {
+      return BadTransportDescription(
+          "Local fingerprint supplied when caller didn't offer DTLS.",
+          error_desc);
+    } else {
+      // We are not doing DTLS
+      remote_fingerprint_.reset(new rtc::SSLFingerprint(
+          "", NULL, 0));
+    }
+
+    // Now run the negotiation for the base class.
+    return Base::NegotiateTransportDescription_w(local_role, error_desc);
+  }
+
+  virtual DtlsTransportChannelWrapper* CreateTransportChannel(int component) {
+    return new DtlsTransportChannelWrapper(
+        this, Base::CreateTransportChannel(component));
+  }
+
+  virtual void DestroyTransportChannel(TransportChannelImpl* channel) {
+    // Kind of ugly, but this lets us do the exact inverse of the create.
+    DtlsTransportChannelWrapper* dtls_channel =
+        static_cast<DtlsTransportChannelWrapper*>(channel);
+    TransportChannelImpl* base_channel = dtls_channel->channel();
+    delete dtls_channel;
+    Base::DestroyTransportChannel(base_channel);
+  }
+
+  virtual bool GetSslRole_w(rtc::SSLRole* ssl_role) const {
+    ASSERT(ssl_role != NULL);
+    *ssl_role = secure_role_;
+    return true;
+  }
+
+ private:
+  virtual bool ApplyNegotiatedTransportDescription_w(
+      TransportChannelImpl* channel,
+      std::string* error_desc) {
+    // Set ssl role. Role must be set before fingerprint is applied, which
+    // initiates DTLS setup.
+    if (!channel->SetSslRole(secure_role_)) {
+      return BadTransportDescription("Failed to set ssl role for the channel.",
+                                     error_desc);
+    }
+    // Apply remote fingerprint.
+    if (!channel->SetRemoteFingerprint(
+        remote_fingerprint_->algorithm,
+        reinterpret_cast<const uint8 *>(remote_fingerprint_->
+                                    digest.data()),
+        remote_fingerprint_->digest.length())) {
+      return BadTransportDescription("Failed to apply remote fingerprint.",
+                                     error_desc);
+    }
+    return Base::ApplyNegotiatedTransportDescription_w(channel, error_desc);
+  }
+
+  rtc::SSLIdentity* identity_;
+  rtc::SSLRole secure_role_;
+  rtc::scoped_ptr<rtc::SSLFingerprint> remote_fingerprint_;
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_DTLSTRANSPORT_H_
diff --git a/webrtc/p2p/base/dtlstransportchannel.cc b/webrtc/p2p/base/dtlstransportchannel.cc
new file mode 100644
index 0000000..9cceca3
--- /dev/null
+++ b/webrtc/p2p/base/dtlstransportchannel.cc
@@ -0,0 +1,623 @@
+/*
+ *  Copyright 2011 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/dtlstransportchannel.h"
+
+#include "webrtc/p2p/base/common.h"
+#include "webrtc/base/buffer.h"
+#include "webrtc/base/dscp.h"
+#include "webrtc/base/messagequeue.h"
+#include "webrtc/base/sslstreamadapter.h"
+#include "webrtc/base/stream.h"
+#include "webrtc/base/thread.h"
+
+namespace cricket {
+
+// We don't pull the RTP constants from rtputils.h, to avoid a layer violation.
+static const size_t kDtlsRecordHeaderLen = 13;
+static const size_t kMaxDtlsPacketLen = 2048;
+static const size_t kMinRtpPacketLen = 12;
+
+static bool IsDtlsPacket(const char* data, size_t len) {
+  const uint8* u = reinterpret_cast<const uint8*>(data);
+  return (len >= kDtlsRecordHeaderLen && (u[0] > 19 && u[0] < 64));
+}
+static bool IsRtpPacket(const char* data, size_t len) {
+  const uint8* u = reinterpret_cast<const uint8*>(data);
+  return (len >= kMinRtpPacketLen && (u[0] & 0xC0) == 0x80);
+}
+
+rtc::StreamResult StreamInterfaceChannel::Read(void* buffer,
+                                                     size_t buffer_len,
+                                                     size_t* read,
+                                                     int* error) {
+  if (state_ == rtc::SS_CLOSED)
+    return rtc::SR_EOS;
+  if (state_ == rtc::SS_OPENING)
+    return rtc::SR_BLOCK;
+
+  return fifo_.Read(buffer, buffer_len, read, error);
+}
+
+rtc::StreamResult StreamInterfaceChannel::Write(const void* data,
+                                                      size_t data_len,
+                                                      size_t* written,
+                                                      int* error) {
+  // Always succeeds, since this is an unreliable transport anyway.
+  // TODO: Should this block if channel_'s temporarily unwritable?
+  rtc::PacketOptions packet_options;
+  channel_->SendPacket(static_cast<const char*>(data), data_len,
+                       packet_options);
+  if (written) {
+    *written = data_len;
+  }
+  return rtc::SR_SUCCESS;
+}
+
+bool StreamInterfaceChannel::OnPacketReceived(const char* data, size_t size) {
+  // We force a read event here to ensure that we don't overflow our FIFO.
+  // Under high packet rate this can occur if we wait for the FIFO to post its
+  // own SE_READ.
+  bool ret = (fifo_.WriteAll(data, size, NULL, NULL) == rtc::SR_SUCCESS);
+  if (ret) {
+    SignalEvent(this, rtc::SE_READ, 0);
+  }
+  return ret;
+}
+
+void StreamInterfaceChannel::OnEvent(rtc::StreamInterface* stream,
+                                     int sig, int err) {
+  SignalEvent(this, sig, err);
+}
+
+DtlsTransportChannelWrapper::DtlsTransportChannelWrapper(
+                                           Transport* transport,
+                                           TransportChannelImpl* channel)
+    : TransportChannelImpl(channel->content_name(), channel->component()),
+      transport_(transport),
+      worker_thread_(rtc::Thread::Current()),
+      channel_(channel),
+      downward_(NULL),
+      dtls_state_(STATE_NONE),
+      local_identity_(NULL),
+      ssl_role_(rtc::SSL_CLIENT) {
+  channel_->SignalReadableState.connect(this,
+      &DtlsTransportChannelWrapper::OnReadableState);
+  channel_->SignalWritableState.connect(this,
+      &DtlsTransportChannelWrapper::OnWritableState);
+  channel_->SignalReadPacket.connect(this,
+      &DtlsTransportChannelWrapper::OnReadPacket);
+  channel_->SignalReadyToSend.connect(this,
+      &DtlsTransportChannelWrapper::OnReadyToSend);
+  channel_->SignalRequestSignaling.connect(this,
+      &DtlsTransportChannelWrapper::OnRequestSignaling);
+  channel_->SignalCandidateReady.connect(this,
+      &DtlsTransportChannelWrapper::OnCandidateReady);
+  channel_->SignalCandidatesAllocationDone.connect(this,
+      &DtlsTransportChannelWrapper::OnCandidatesAllocationDone);
+  channel_->SignalRoleConflict.connect(this,
+      &DtlsTransportChannelWrapper::OnRoleConflict);
+  channel_->SignalRouteChange.connect(this,
+      &DtlsTransportChannelWrapper::OnRouteChange);
+  channel_->SignalConnectionRemoved.connect(this,
+      &DtlsTransportChannelWrapper::OnConnectionRemoved);
+}
+
+DtlsTransportChannelWrapper::~DtlsTransportChannelWrapper() {
+}
+
+void DtlsTransportChannelWrapper::Connect() {
+  // We should only get a single call to Connect.
+  ASSERT(dtls_state_ == STATE_NONE ||
+         dtls_state_ == STATE_OFFERED ||
+         dtls_state_ == STATE_ACCEPTED);
+  channel_->Connect();
+}
+
+void DtlsTransportChannelWrapper::Reset() {
+  channel_->Reset();
+  set_writable(false);
+  set_readable(false);
+
+  // Re-call SetupDtls()
+  if (!SetupDtls()) {
+    LOG_J(LS_ERROR, this) << "Error re-initializing DTLS";
+    dtls_state_ = STATE_CLOSED;
+    return;
+  }
+
+  dtls_state_ = STATE_ACCEPTED;
+}
+
+bool DtlsTransportChannelWrapper::SetLocalIdentity(
+    rtc::SSLIdentity* identity) {
+  if (dtls_state_ != STATE_NONE) {
+    if (identity == local_identity_) {
+      // This may happen during renegotiation.
+      LOG_J(LS_INFO, this) << "Ignoring identical DTLS identity";
+      return true;
+    } else {
+      LOG_J(LS_ERROR, this) << "Can't change DTLS local identity in this state";
+      return false;
+    }
+  }
+
+  if (identity) {
+    local_identity_ = identity;
+    dtls_state_ = STATE_OFFERED;
+  } else {
+    LOG_J(LS_INFO, this) << "NULL DTLS identity supplied. Not doing DTLS";
+  }
+
+  return true;
+}
+
+bool DtlsTransportChannelWrapper::GetLocalIdentity(
+    rtc::SSLIdentity** identity) const {
+  if (!local_identity_)
+    return false;
+
+  *identity = local_identity_->GetReference();
+  return true;
+}
+
+bool DtlsTransportChannelWrapper::SetSslRole(rtc::SSLRole role) {
+  if (dtls_state_ == STATE_OPEN) {
+    if (ssl_role_ != role) {
+      LOG(LS_ERROR) << "SSL Role can't be reversed after the session is setup.";
+      return false;
+    }
+    return true;
+  }
+
+  ssl_role_ = role;
+  return true;
+}
+
+bool DtlsTransportChannelWrapper::GetSslRole(rtc::SSLRole* role) const {
+  *role = ssl_role_;
+  return true;
+}
+
+bool DtlsTransportChannelWrapper::SetRemoteFingerprint(
+    const std::string& digest_alg,
+    const uint8* digest,
+    size_t digest_len) {
+
+  rtc::Buffer remote_fingerprint_value(digest, digest_len);
+
+  if (dtls_state_ != STATE_NONE &&
+      remote_fingerprint_value_ == remote_fingerprint_value &&
+      !digest_alg.empty()) {
+    // This may happen during renegotiation.
+    LOG_J(LS_INFO, this) << "Ignoring identical remote DTLS fingerprint";
+    return true;
+  }
+
+  // Allow SetRemoteFingerprint with a NULL digest even if SetLocalIdentity
+  // hasn't been called.
+  if (dtls_state_ > STATE_OFFERED ||
+      (dtls_state_ == STATE_NONE && !digest_alg.empty())) {
+    LOG_J(LS_ERROR, this) << "Can't set DTLS remote settings in this state.";
+    return false;
+  }
+
+  if (digest_alg.empty()) {
+    LOG_J(LS_INFO, this) << "Other side didn't support DTLS.";
+    dtls_state_ = STATE_NONE;
+    return true;
+  }
+
+  // At this point we know we are doing DTLS
+  remote_fingerprint_value.TransferTo(&remote_fingerprint_value_);
+  remote_fingerprint_algorithm_ = digest_alg;
+
+  if (!SetupDtls()) {
+    dtls_state_ = STATE_CLOSED;
+    return false;
+  }
+
+  dtls_state_ = STATE_ACCEPTED;
+  return true;
+}
+
+bool DtlsTransportChannelWrapper::GetRemoteCertificate(
+    rtc::SSLCertificate** cert) const {
+  if (!dtls_)
+    return false;
+
+  return dtls_->GetPeerCertificate(cert);
+}
+
+bool DtlsTransportChannelWrapper::SetupDtls() {
+  StreamInterfaceChannel* downward =
+      new StreamInterfaceChannel(worker_thread_, channel_);
+
+  dtls_.reset(rtc::SSLStreamAdapter::Create(downward));
+  if (!dtls_) {
+    LOG_J(LS_ERROR, this) << "Failed to create DTLS adapter.";
+    delete downward;
+    return false;
+  }
+
+  downward_ = downward;
+
+  dtls_->SetIdentity(local_identity_->GetReference());
+  dtls_->SetMode(rtc::SSL_MODE_DTLS);
+  dtls_->SetServerRole(ssl_role_);
+  dtls_->SignalEvent.connect(this, &DtlsTransportChannelWrapper::OnDtlsEvent);
+  if (!dtls_->SetPeerCertificateDigest(
+          remote_fingerprint_algorithm_,
+          reinterpret_cast<unsigned char *>(remote_fingerprint_value_.data()),
+          remote_fingerprint_value_.length())) {
+    LOG_J(LS_ERROR, this) << "Couldn't set DTLS certificate digest.";
+    return false;
+  }
+
+  // Set up DTLS-SRTP, if it's been enabled.
+  if (!srtp_ciphers_.empty()) {
+    if (!dtls_->SetDtlsSrtpCiphers(srtp_ciphers_)) {
+      LOG_J(LS_ERROR, this) << "Couldn't set DTLS-SRTP ciphers.";
+      return false;
+    }
+  } else {
+    LOG_J(LS_INFO, this) << "Not using DTLS.";
+  }
+
+  LOG_J(LS_INFO, this) << "DTLS setup complete.";
+  return true;
+}
+
+bool DtlsTransportChannelWrapper::SetSrtpCiphers(
+    const std::vector<std::string>& ciphers) {
+  if (srtp_ciphers_ == ciphers)
+    return true;
+
+  if (dtls_state_ == STATE_STARTED) {
+    LOG(LS_WARNING) << "Ignoring new SRTP ciphers while DTLS is negotiating";
+    return true;
+  }
+
+  if (dtls_state_ == STATE_OPEN) {
+    // We don't support DTLS renegotiation currently. If new set of srtp ciphers
+    // are different than what's being used currently, we will not use it.
+    // So for now, let's be happy (or sad) with a warning message.
+    std::string current_srtp_cipher;
+    if (!dtls_->GetDtlsSrtpCipher(&current_srtp_cipher)) {
+      LOG(LS_ERROR) << "Failed to get the current SRTP cipher for DTLS channel";
+      return false;
+    }
+    const std::vector<std::string>::const_iterator iter =
+        std::find(ciphers.begin(), ciphers.end(), current_srtp_cipher);
+    if (iter == ciphers.end()) {
+      std::string requested_str;
+      for (size_t i = 0; i < ciphers.size(); ++i) {
+        requested_str.append(" ");
+        requested_str.append(ciphers[i]);
+        requested_str.append(" ");
+      }
+      LOG(LS_WARNING) << "Ignoring new set of SRTP ciphers, as DTLS "
+                      << "renegotiation is not supported currently "
+                      << "current cipher = " << current_srtp_cipher << " and "
+                      << "requested = " << "[" << requested_str << "]";
+    }
+    return true;
+  }
+
+  if (dtls_state_ != STATE_NONE &&
+      dtls_state_ != STATE_OFFERED &&
+      dtls_state_ != STATE_ACCEPTED) {
+    ASSERT(false);
+    return false;
+  }
+
+  srtp_ciphers_ = ciphers;
+  return true;
+}
+
+bool DtlsTransportChannelWrapper::GetSrtpCipher(std::string* cipher) {
+  if (dtls_state_ != STATE_OPEN) {
+    return false;
+  }
+
+  return dtls_->GetDtlsSrtpCipher(cipher);
+}
+
+
+// Called from upper layers to send a media packet.
+int DtlsTransportChannelWrapper::SendPacket(
+    const char* data, size_t size,
+    const rtc::PacketOptions& options, int flags) {
+  int result = -1;
+
+  switch (dtls_state_) {
+    case STATE_OFFERED:
+      // We don't know if we are doing DTLS yet, so we can't send a packet.
+      // TODO(ekr@rtfm.com): assert here?
+      result = -1;
+      break;
+
+    case STATE_STARTED:
+    case STATE_ACCEPTED:
+      // Can't send data until the connection is active
+      result = -1;
+      break;
+
+    case STATE_OPEN:
+      if (flags & PF_SRTP_BYPASS) {
+        ASSERT(!srtp_ciphers_.empty());
+        if (!IsRtpPacket(data, size)) {
+          result = -1;
+          break;
+        }
+
+        result = channel_->SendPacket(data, size, options);
+      } else {
+        result = (dtls_->WriteAll(data, size, NULL, NULL) ==
+          rtc::SR_SUCCESS) ? static_cast<int>(size) : -1;
+      }
+      break;
+      // Not doing DTLS.
+    case STATE_NONE:
+      result = channel_->SendPacket(data, size, options);
+      break;
+
+    case STATE_CLOSED:  // Can't send anything when we're closed.
+      return -1;
+  }
+
+  return result;
+}
+
+// The state transition logic here is as follows:
+// (1) If we're not doing DTLS-SRTP, then the state is just the
+//     state of the underlying impl()
+// (2) If we're doing DTLS-SRTP:
+//     - Prior to the DTLS handshake, the state is neither readable or
+//       writable
+//     - When the impl goes writable for the first time we
+//       start the DTLS handshake
+//     - Once the DTLS handshake completes, the state is that of the
+//       impl again
+void DtlsTransportChannelWrapper::OnReadableState(TransportChannel* channel) {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  ASSERT(channel == channel_);
+  LOG_J(LS_VERBOSE, this)
+      << "DTLSTransportChannelWrapper: channel readable state changed.";
+
+  if (dtls_state_ == STATE_NONE || dtls_state_ == STATE_OPEN) {
+    set_readable(channel_->readable());
+    // Note: SignalReadableState fired by set_readable.
+  }
+}
+
+void DtlsTransportChannelWrapper::OnWritableState(TransportChannel* channel) {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  ASSERT(channel == channel_);
+  LOG_J(LS_VERBOSE, this)
+      << "DTLSTransportChannelWrapper: channel writable state changed.";
+
+  switch (dtls_state_) {
+    case STATE_NONE:
+    case STATE_OPEN:
+      set_writable(channel_->writable());
+      // Note: SignalWritableState fired by set_writable.
+      break;
+
+    case STATE_OFFERED:
+      // Do nothing
+      break;
+
+    case STATE_ACCEPTED:
+      if (!MaybeStartDtls()) {
+        // This should never happen:
+        // Because we are operating in a nonblocking mode and all
+        // incoming packets come in via OnReadPacket(), which rejects
+        // packets in this state, the incoming queue must be empty. We
+        // ignore write errors, thus any errors must be because of
+        // configuration and therefore are our fault.
+        // Note that in non-debug configurations, failure in
+        // MaybeStartDtls() changes the state to STATE_CLOSED.
+        ASSERT(false);
+      }
+      break;
+
+    case STATE_STARTED:
+      // Do nothing
+      break;
+
+    case STATE_CLOSED:
+      // Should not happen. Do nothing
+      break;
+  }
+}
+
+void DtlsTransportChannelWrapper::OnReadPacket(
+    TransportChannel* channel, const char* data, size_t size,
+    const rtc::PacketTime& packet_time, int flags) {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  ASSERT(channel == channel_);
+  ASSERT(flags == 0);
+
+  switch (dtls_state_) {
+    case STATE_NONE:
+      // We are not doing DTLS
+      SignalReadPacket(this, data, size, packet_time, 0);
+      break;
+
+    case STATE_OFFERED:
+      // Currently drop the packet, but we might in future
+      // decide to take this as evidence that the other
+      // side is ready to do DTLS and start the handshake
+      // on our end
+      LOG_J(LS_WARNING, this) << "Received packet before we know if we are "
+                              << "doing DTLS or not; dropping.";
+      break;
+
+    case STATE_ACCEPTED:
+      // Drop packets received before DTLS has actually started
+      LOG_J(LS_INFO, this) << "Dropping packet received before DTLS started.";
+      break;
+
+    case STATE_STARTED:
+    case STATE_OPEN:
+      // We should only get DTLS or SRTP packets; STUN's already been demuxed.
+      // Is this potentially a DTLS packet?
+      if (IsDtlsPacket(data, size)) {
+        if (!HandleDtlsPacket(data, size)) {
+          LOG_J(LS_ERROR, this) << "Failed to handle DTLS packet.";
+          return;
+        }
+      } else {
+        // Not a DTLS packet; our handshake should be complete by now.
+        if (dtls_state_ != STATE_OPEN) {
+          LOG_J(LS_ERROR, this) << "Received non-DTLS packet before DTLS "
+                                << "complete.";
+          return;
+        }
+
+        // And it had better be a SRTP packet.
+        if (!IsRtpPacket(data, size)) {
+          LOG_J(LS_ERROR, this) << "Received unexpected non-DTLS packet.";
+          return;
+        }
+
+        // Sanity check.
+        ASSERT(!srtp_ciphers_.empty());
+
+        // Signal this upwards as a bypass packet.
+        SignalReadPacket(this, data, size, packet_time, PF_SRTP_BYPASS);
+      }
+      break;
+    case STATE_CLOSED:
+      // This shouldn't be happening. Drop the packet
+      break;
+  }
+}
+
+void DtlsTransportChannelWrapper::OnReadyToSend(TransportChannel* channel) {
+  if (writable()) {
+    SignalReadyToSend(this);
+  }
+}
+
+void DtlsTransportChannelWrapper::OnDtlsEvent(rtc::StreamInterface* dtls,
+                                              int sig, int err) {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  ASSERT(dtls == dtls_.get());
+  if (sig & rtc::SE_OPEN) {
+    // This is the first time.
+    LOG_J(LS_INFO, this) << "DTLS handshake complete.";
+    if (dtls_->GetState() == rtc::SS_OPEN) {
+      // The check for OPEN shouldn't be necessary but let's make
+      // sure we don't accidentally frob the state if it's closed.
+      dtls_state_ = STATE_OPEN;
+
+      set_readable(true);
+      set_writable(true);
+    }
+  }
+  if (sig & rtc::SE_READ) {
+    char buf[kMaxDtlsPacketLen];
+    size_t read;
+    if (dtls_->Read(buf, sizeof(buf), &read, NULL) == rtc::SR_SUCCESS) {
+      SignalReadPacket(this, buf, read, rtc::CreatePacketTime(0), 0);
+    }
+  }
+  if (sig & rtc::SE_CLOSE) {
+    ASSERT(sig == rtc::SE_CLOSE);  // SE_CLOSE should be by itself.
+    if (!err) {
+      LOG_J(LS_INFO, this) << "DTLS channel closed";
+    } else {
+      LOG_J(LS_INFO, this) << "DTLS channel error, code=" << err;
+    }
+
+    set_readable(false);
+    set_writable(false);
+    dtls_state_ = STATE_CLOSED;
+  }
+}
+
+bool DtlsTransportChannelWrapper::MaybeStartDtls() {
+  if (channel_->writable()) {
+    if (dtls_->StartSSLWithPeer()) {
+      LOG_J(LS_ERROR, this) << "Couldn't start DTLS handshake";
+      dtls_state_ = STATE_CLOSED;
+      return false;
+    }
+    LOG_J(LS_INFO, this)
+      << "DtlsTransportChannelWrapper: Started DTLS handshake";
+
+    dtls_state_ = STATE_STARTED;
+  }
+  return true;
+}
+
+// Called from OnReadPacket when a DTLS packet is received.
+bool DtlsTransportChannelWrapper::HandleDtlsPacket(const char* data,
+                                                   size_t size) {
+  // Sanity check we're not passing junk that
+  // just looks like DTLS.
+  const uint8* tmp_data = reinterpret_cast<const uint8* >(data);
+  size_t tmp_size = size;
+  while (tmp_size > 0) {
+    if (tmp_size < kDtlsRecordHeaderLen)
+      return false;  // Too short for the header
+
+    size_t record_len = (tmp_data[11] << 8) | (tmp_data[12]);
+    if ((record_len + kDtlsRecordHeaderLen) > tmp_size)
+      return false;  // Body too short
+
+    tmp_data += record_len + kDtlsRecordHeaderLen;
+    tmp_size -= record_len + kDtlsRecordHeaderLen;
+  }
+
+  // Looks good. Pass to the SIC which ends up being passed to
+  // the DTLS stack.
+  return downward_->OnPacketReceived(data, size);
+}
+
+void DtlsTransportChannelWrapper::OnRequestSignaling(
+    TransportChannelImpl* channel) {
+  ASSERT(channel == channel_);
+  SignalRequestSignaling(this);
+}
+
+void DtlsTransportChannelWrapper::OnCandidateReady(
+    TransportChannelImpl* channel, const Candidate& c) {
+  ASSERT(channel == channel_);
+  SignalCandidateReady(this, c);
+}
+
+void DtlsTransportChannelWrapper::OnCandidatesAllocationDone(
+    TransportChannelImpl* channel) {
+  ASSERT(channel == channel_);
+  SignalCandidatesAllocationDone(this);
+}
+
+void DtlsTransportChannelWrapper::OnRoleConflict(
+    TransportChannelImpl* channel) {
+  ASSERT(channel == channel_);
+  SignalRoleConflict(this);
+}
+
+void DtlsTransportChannelWrapper::OnRouteChange(
+    TransportChannel* channel, const Candidate& candidate) {
+  ASSERT(channel == channel_);
+  SignalRouteChange(this, candidate);
+}
+
+void DtlsTransportChannelWrapper::OnConnectionRemoved(
+    TransportChannelImpl* channel) {
+  ASSERT(channel == channel_);
+  SignalConnectionRemoved(this);
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/dtlstransportchannel.h b/webrtc/p2p/base/dtlstransportchannel.h
new file mode 100644
index 0000000..d12f724
--- /dev/null
+++ b/webrtc/p2p/base/dtlstransportchannel.h
@@ -0,0 +1,246 @@
+/*
+ *  Copyright 2011 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_DTLSTRANSPORTCHANNEL_H_
+#define WEBRTC_P2P_BASE_DTLSTRANSPORTCHANNEL_H_
+
+#include <string>
+#include <vector>
+
+#include "webrtc/p2p/base/transportchannelimpl.h"
+#include "webrtc/base/buffer.h"
+#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/sslstreamadapter.h"
+#include "webrtc/base/stream.h"
+
+namespace cricket {
+
+// A bridge between a packet-oriented/channel-type interface on
+// the bottom and a StreamInterface on the top.
+class StreamInterfaceChannel : public rtc::StreamInterface,
+                               public sigslot::has_slots<> {
+ public:
+  StreamInterfaceChannel(rtc::Thread* owner, TransportChannel* channel)
+      : channel_(channel),
+        state_(rtc::SS_OPEN),
+        fifo_(kFifoSize, owner) {
+    fifo_.SignalEvent.connect(this, &StreamInterfaceChannel::OnEvent);
+  }
+
+  // Push in a packet; this gets pulled out from Read().
+  bool OnPacketReceived(const char* data, size_t size);
+
+  // Implementations of StreamInterface
+  virtual rtc::StreamState GetState() const { return state_; }
+  virtual void Close() { state_ = rtc::SS_CLOSED; }
+  virtual rtc::StreamResult Read(void* buffer, size_t buffer_len,
+                                       size_t* read, int* error);
+  virtual rtc::StreamResult Write(const void* data, size_t data_len,
+                                        size_t* written, int* error);
+
+ private:
+  static const size_t kFifoSize = 8192;
+
+  // Forward events
+  virtual void OnEvent(rtc::StreamInterface* stream, int sig, int err);
+
+  TransportChannel* channel_;  // owned by DtlsTransportChannelWrapper
+  rtc::StreamState state_;
+  rtc::FifoBuffer fifo_;
+
+  DISALLOW_COPY_AND_ASSIGN(StreamInterfaceChannel);
+};
+
+
+// This class provides a DTLS SSLStreamAdapter inside a TransportChannel-style
+// packet-based interface, wrapping an existing TransportChannel instance
+// (e.g a P2PTransportChannel)
+// Here's the way this works:
+//
+//   DtlsTransportChannelWrapper {
+//       SSLStreamAdapter* dtls_ {
+//           StreamInterfaceChannel downward_ {
+//               TransportChannelImpl* channel_;
+//           }
+//       }
+//   }
+//
+//   - Data which comes into DtlsTransportChannelWrapper from the underlying
+//     channel_ via OnReadPacket() is checked for whether it is DTLS
+//     or not, and if it is, is passed to DtlsTransportChannelWrapper::
+//     HandleDtlsPacket, which pushes it into to downward_.
+//     dtls_ is listening for events on downward_, so it immediately calls
+//     downward_->Read().
+//
+//   - Data written to DtlsTransportChannelWrapper is passed either to
+//      downward_ or directly to channel_, depending on whether DTLS is
+//     negotiated and whether the flags include PF_SRTP_BYPASS
+//
+//   - The SSLStreamAdapter writes to downward_->Write()
+//     which translates it into packet writes on channel_.
+class DtlsTransportChannelWrapper : public TransportChannelImpl {
+ public:
+    enum State {
+      STATE_NONE,      // No state or rejected.
+      STATE_OFFERED,   // Our identity has been set.
+      STATE_ACCEPTED,  // The other side sent a fingerprint.
+      STATE_STARTED,   // We are negotiating.
+      STATE_OPEN,      // Negotiation complete.
+      STATE_CLOSED     // Connection closed.
+    };
+
+  // The parameters here are:
+  // transport -- the DtlsTransport that created us
+  // channel -- the TransportChannel we are wrapping
+  DtlsTransportChannelWrapper(Transport* transport,
+                              TransportChannelImpl* channel);
+  virtual ~DtlsTransportChannelWrapper();
+
+  virtual void SetIceRole(IceRole role) {
+    channel_->SetIceRole(role);
+  }
+  virtual IceRole GetIceRole() const {
+    return channel_->GetIceRole();
+  }
+  virtual size_t GetConnectionCount() const {
+    return channel_->GetConnectionCount();
+  }
+  virtual bool SetLocalIdentity(rtc::SSLIdentity *identity);
+  virtual bool GetLocalIdentity(rtc::SSLIdentity** identity) const;
+
+  virtual bool SetRemoteFingerprint(const std::string& digest_alg,
+                                    const uint8* digest,
+                                    size_t digest_len);
+  virtual bool IsDtlsActive() const { return dtls_state_ != STATE_NONE; }
+
+  // Called to send a packet (via DTLS, if turned on).
+  virtual int SendPacket(const char* data, size_t size,
+                         const rtc::PacketOptions& options,
+                         int flags);
+
+  // TransportChannel calls that we forward to the wrapped transport.
+  virtual int SetOption(rtc::Socket::Option opt, int value) {
+    return channel_->SetOption(opt, value);
+  }
+  virtual int GetError() {
+    return channel_->GetError();
+  }
+  virtual bool GetStats(ConnectionInfos* infos) {
+    return channel_->GetStats(infos);
+  }
+  virtual const std::string SessionId() const {
+    return channel_->SessionId();
+  }
+
+  // Set up the ciphers to use for DTLS-SRTP. If this method is not called
+  // before DTLS starts, or |ciphers| is empty, SRTP keys won't be negotiated.
+  // This method should be called before SetupDtls.
+  virtual bool SetSrtpCiphers(const std::vector<std::string>& ciphers);
+
+  // Find out which DTLS-SRTP cipher was negotiated
+  virtual bool GetSrtpCipher(std::string* cipher);
+
+  virtual bool GetSslRole(rtc::SSLRole* role) const;
+  virtual bool SetSslRole(rtc::SSLRole role);
+
+  // Once DTLS has been established, this method retrieves the certificate in
+  // use by the remote peer, for use in external identity verification.
+  virtual bool GetRemoteCertificate(rtc::SSLCertificate** cert) const;
+
+  // Once DTLS has established (i.e., this channel is writable), this method
+  // extracts the keys negotiated during the DTLS handshake, for use in external
+  // encryption. DTLS-SRTP uses this to extract the needed SRTP keys.
+  // See the SSLStreamAdapter documentation for info on the specific parameters.
+  virtual bool ExportKeyingMaterial(const std::string& label,
+                                    const uint8* context,
+                                    size_t context_len,
+                                    bool use_context,
+                                    uint8* result,
+                                    size_t result_len) {
+    return (dtls_.get()) ? dtls_->ExportKeyingMaterial(label, context,
+                                                       context_len,
+                                                       use_context,
+                                                       result, result_len)
+        : false;
+  }
+
+  // TransportChannelImpl calls.
+  virtual Transport* GetTransport() {
+    return transport_;
+  }
+  virtual void SetIceTiebreaker(uint64 tiebreaker) {
+    channel_->SetIceTiebreaker(tiebreaker);
+  }
+  virtual bool GetIceProtocolType(IceProtocolType* type) const {
+    return channel_->GetIceProtocolType(type);
+  }
+  virtual void SetIceProtocolType(IceProtocolType type) {
+    channel_->SetIceProtocolType(type);
+  }
+  virtual void SetIceCredentials(const std::string& ice_ufrag,
+                                 const std::string& ice_pwd) {
+    channel_->SetIceCredentials(ice_ufrag, ice_pwd);
+  }
+  virtual void SetRemoteIceCredentials(const std::string& ice_ufrag,
+                                       const std::string& ice_pwd) {
+    channel_->SetRemoteIceCredentials(ice_ufrag, ice_pwd);
+  }
+  virtual void SetRemoteIceMode(IceMode mode) {
+    channel_->SetRemoteIceMode(mode);
+  }
+
+  virtual void Connect();
+  virtual void Reset();
+
+  virtual void OnSignalingReady() {
+    channel_->OnSignalingReady();
+  }
+  virtual void OnCandidate(const Candidate& candidate) {
+    channel_->OnCandidate(candidate);
+  }
+
+  // Needed by DtlsTransport.
+  TransportChannelImpl* channel() { return channel_; }
+
+ private:
+  void OnReadableState(TransportChannel* channel);
+  void OnWritableState(TransportChannel* channel);
+  void OnReadPacket(TransportChannel* channel, const char* data, size_t size,
+                    const rtc::PacketTime& packet_time, int flags);
+  void OnReadyToSend(TransportChannel* channel);
+  void OnDtlsEvent(rtc::StreamInterface* stream_, int sig, int err);
+  bool SetupDtls();
+  bool MaybeStartDtls();
+  bool HandleDtlsPacket(const char* data, size_t size);
+  void OnRequestSignaling(TransportChannelImpl* channel);
+  void OnCandidateReady(TransportChannelImpl* channel, const Candidate& c);
+  void OnCandidatesAllocationDone(TransportChannelImpl* channel);
+  void OnRoleConflict(TransportChannelImpl* channel);
+  void OnRouteChange(TransportChannel* channel, const Candidate& candidate);
+  void OnConnectionRemoved(TransportChannelImpl* channel);
+
+  Transport* transport_;  // The transport_ that created us.
+  rtc::Thread* worker_thread_;  // Everything should occur on this thread.
+  TransportChannelImpl* channel_;  // Underlying channel, owned by transport_.
+  rtc::scoped_ptr<rtc::SSLStreamAdapter> dtls_;  // The DTLS stream
+  StreamInterfaceChannel* downward_;  // Wrapper for channel_, owned by dtls_.
+  std::vector<std::string> srtp_ciphers_;  // SRTP ciphers to use with DTLS.
+  State dtls_state_;
+  rtc::SSLIdentity* local_identity_;
+  rtc::SSLRole ssl_role_;
+  rtc::Buffer remote_fingerprint_value_;
+  std::string remote_fingerprint_algorithm_;
+
+  DISALLOW_COPY_AND_ASSIGN(DtlsTransportChannelWrapper);
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_DTLSTRANSPORTCHANNEL_H_
diff --git a/webrtc/p2p/base/dtlstransportchannel_unittest.cc b/webrtc/p2p/base/dtlstransportchannel_unittest.cc
new file mode 100644
index 0000000..52f8c1e
--- /dev/null
+++ b/webrtc/p2p/base/dtlstransportchannel_unittest.cc
@@ -0,0 +1,823 @@
+/*
+ *  Copyright 2011 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <set>
+
+#include "webrtc/p2p/base/dtlstransport.h"
+#include "webrtc/p2p/base/fakesession.h"
+#include "webrtc/base/common.h"
+#include "webrtc/base/dscp.h"
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/helpers.h"
+#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/ssladapter.h"
+#include "webrtc/base/sslidentity.h"
+#include "webrtc/base/sslstreamadapter.h"
+#include "webrtc/base/stringutils.h"
+#include "webrtc/base/thread.h"
+
+#define MAYBE_SKIP_TEST(feature)                    \
+  if (!(rtc::SSLStreamAdapter::feature())) {  \
+    LOG(LS_INFO) << "Feature disabled... skipping"; \
+    return;                                         \
+  }
+
+static const char AES_CM_128_HMAC_SHA1_80[] = "AES_CM_128_HMAC_SHA1_80";
+static const char kIceUfrag1[] = "TESTICEUFRAG0001";
+static const char kIcePwd1[] = "TESTICEPWD00000000000001";
+static const size_t kPacketNumOffset = 8;
+static const size_t kPacketHeaderLen = 12;
+
+static bool IsRtpLeadByte(uint8 b) {
+  return ((b & 0xC0) == 0x80);
+}
+
+using cricket::ConnectionRole;
+
+enum Flags { NF_REOFFER = 0x1, NF_EXPECT_FAILURE = 0x2 };
+
+class DtlsTestClient : public sigslot::has_slots<> {
+ public:
+  DtlsTestClient(const std::string& name,
+                 rtc::Thread* signaling_thread,
+                 rtc::Thread* worker_thread) :
+      name_(name),
+      signaling_thread_(signaling_thread),
+      worker_thread_(worker_thread),
+      protocol_(cricket::ICEPROTO_GOOGLE),
+      packet_size_(0),
+      use_dtls_srtp_(false),
+      negotiated_dtls_(false),
+      received_dtls_client_hello_(false),
+      received_dtls_server_hello_(false) {
+  }
+  void SetIceProtocol(cricket::TransportProtocol proto) {
+    protocol_ = proto;
+  }
+  void CreateIdentity() {
+    identity_.reset(rtc::SSLIdentity::Generate(name_));
+  }
+  rtc::SSLIdentity* identity() { return identity_.get(); }
+  void SetupSrtp() {
+    ASSERT(identity_.get() != NULL);
+    use_dtls_srtp_ = true;
+  }
+  void SetupChannels(int count, cricket::IceRole role) {
+    transport_.reset(new cricket::DtlsTransport<cricket::FakeTransport>(
+        signaling_thread_, worker_thread_, "dtls content name", NULL,
+        identity_.get()));
+    transport_->SetAsync(true);
+    transport_->SetIceRole(role);
+    transport_->SetIceTiebreaker(
+        (role == cricket::ICEROLE_CONTROLLING) ? 1 : 2);
+    transport_->SignalWritableState.connect(this,
+        &DtlsTestClient::OnTransportWritableState);
+
+    for (int i = 0; i < count; ++i) {
+      cricket::DtlsTransportChannelWrapper* channel =
+          static_cast<cricket::DtlsTransportChannelWrapper*>(
+              transport_->CreateChannel(i));
+      ASSERT_TRUE(channel != NULL);
+      channel->SignalWritableState.connect(this,
+        &DtlsTestClient::OnTransportChannelWritableState);
+      channel->SignalReadPacket.connect(this,
+        &DtlsTestClient::OnTransportChannelReadPacket);
+      channels_.push_back(channel);
+
+      // Hook the raw packets so that we can verify they are encrypted.
+      channel->channel()->SignalReadPacket.connect(
+          this, &DtlsTestClient::OnFakeTransportChannelReadPacket);
+    }
+  }
+
+  cricket::Transport* transport() { return transport_.get(); }
+
+  cricket::FakeTransportChannel* GetFakeChannel(int component) {
+    cricket::TransportChannelImpl* ch = transport_->GetChannel(component);
+    cricket::DtlsTransportChannelWrapper* wrapper =
+        static_cast<cricket::DtlsTransportChannelWrapper*>(ch);
+    return (wrapper) ?
+        static_cast<cricket::FakeTransportChannel*>(wrapper->channel()) : NULL;
+  }
+
+  // Offer DTLS if we have an identity; pass in a remote fingerprint only if
+  // both sides support DTLS.
+  void Negotiate(DtlsTestClient* peer, cricket::ContentAction action,
+                 ConnectionRole local_role, ConnectionRole remote_role,
+                 int flags) {
+    Negotiate(identity_.get(), (identity_) ? peer->identity_.get() : NULL,
+              action, local_role, remote_role, flags);
+  }
+
+  // Allow any DTLS configuration to be specified (including invalid ones).
+  void Negotiate(rtc::SSLIdentity* local_identity,
+                 rtc::SSLIdentity* remote_identity,
+                 cricket::ContentAction action,
+                 ConnectionRole local_role,
+                 ConnectionRole remote_role,
+                 int flags) {
+    rtc::scoped_ptr<rtc::SSLFingerprint> local_fingerprint;
+    rtc::scoped_ptr<rtc::SSLFingerprint> remote_fingerprint;
+    if (local_identity) {
+      local_fingerprint.reset(rtc::SSLFingerprint::Create(
+          rtc::DIGEST_SHA_1, local_identity));
+      ASSERT_TRUE(local_fingerprint.get() != NULL);
+    }
+    if (remote_identity) {
+      remote_fingerprint.reset(rtc::SSLFingerprint::Create(
+          rtc::DIGEST_SHA_1, remote_identity));
+      ASSERT_TRUE(remote_fingerprint.get() != NULL);
+    }
+
+    if (use_dtls_srtp_ && !(flags & NF_REOFFER)) {
+      // SRTP ciphers will be set only in the beginning.
+      for (std::vector<cricket::DtlsTransportChannelWrapper*>::iterator it =
+           channels_.begin(); it != channels_.end(); ++it) {
+        std::vector<std::string> ciphers;
+        ciphers.push_back(AES_CM_128_HMAC_SHA1_80);
+        ASSERT_TRUE((*it)->SetSrtpCiphers(ciphers));
+      }
+    }
+
+    std::string transport_type = (protocol_ == cricket::ICEPROTO_GOOGLE) ?
+        cricket::NS_GINGLE_P2P : cricket::NS_JINGLE_ICE_UDP;
+    cricket::TransportDescription local_desc(
+        transport_type, std::vector<std::string>(), kIceUfrag1, kIcePwd1,
+        cricket::ICEMODE_FULL, local_role,
+         // If remote if the offerer and has no DTLS support, answer will be
+        // without any fingerprint.
+        (action == cricket::CA_ANSWER && !remote_identity) ?
+            NULL : local_fingerprint.get(),
+        cricket::Candidates());
+
+    cricket::TransportDescription remote_desc(
+        transport_type, std::vector<std::string>(), kIceUfrag1, kIcePwd1,
+        cricket::ICEMODE_FULL, remote_role, remote_fingerprint.get(),
+        cricket::Candidates());
+
+    bool expect_success = (flags & NF_EXPECT_FAILURE) ? false : true;
+    // If |expect_success| is false, expect SRTD or SLTD to fail when
+    // content action is CA_ANSWER.
+    if (action == cricket::CA_OFFER) {
+      ASSERT_TRUE(transport_->SetLocalTransportDescription(
+          local_desc, cricket::CA_OFFER, NULL));
+      ASSERT_EQ(expect_success, transport_->SetRemoteTransportDescription(
+          remote_desc, cricket::CA_ANSWER, NULL));
+    } else {
+      ASSERT_TRUE(transport_->SetRemoteTransportDescription(
+          remote_desc, cricket::CA_OFFER, NULL));
+      ASSERT_EQ(expect_success, transport_->SetLocalTransportDescription(
+          local_desc, cricket::CA_ANSWER, NULL));
+    }
+    negotiated_dtls_ = (local_identity && remote_identity);
+  }
+
+  bool Connect(DtlsTestClient* peer) {
+    transport_->ConnectChannels();
+    transport_->SetDestination(peer->transport_.get());
+    return true;
+  }
+
+  bool writable() const { return transport_->writable(); }
+
+  void CheckRole(rtc::SSLRole role) {
+    if (role == rtc::SSL_CLIENT) {
+      ASSERT_FALSE(received_dtls_client_hello_);
+      ASSERT_TRUE(received_dtls_server_hello_);
+    } else {
+      ASSERT_TRUE(received_dtls_client_hello_);
+      ASSERT_FALSE(received_dtls_server_hello_);
+    }
+  }
+
+  void CheckSrtp(const std::string& expected_cipher) {
+    for (std::vector<cricket::DtlsTransportChannelWrapper*>::iterator it =
+           channels_.begin(); it != channels_.end(); ++it) {
+      std::string cipher;
+
+      bool rv = (*it)->GetSrtpCipher(&cipher);
+      if (negotiated_dtls_ && !expected_cipher.empty()) {
+        ASSERT_TRUE(rv);
+
+        ASSERT_EQ(cipher, expected_cipher);
+      } else {
+        ASSERT_FALSE(rv);
+      }
+    }
+  }
+
+  void SendPackets(size_t channel, size_t size, size_t count, bool srtp) {
+    ASSERT(channel < channels_.size());
+    rtc::scoped_ptr<char[]> packet(new char[size]);
+    size_t sent = 0;
+    do {
+      // Fill the packet with a known value and a sequence number to check
+      // against, and make sure that it doesn't look like DTLS.
+      memset(packet.get(), sent & 0xff, size);
+      packet[0] = (srtp) ? 0x80 : 0x00;
+      rtc::SetBE32(packet.get() + kPacketNumOffset,
+                         static_cast<uint32>(sent));
+
+      // Only set the bypass flag if we've activated DTLS.
+      int flags = (identity_.get() && srtp) ? cricket::PF_SRTP_BYPASS : 0;
+      rtc::PacketOptions packet_options;
+      int rv = channels_[channel]->SendPacket(
+          packet.get(), size, packet_options, flags);
+      ASSERT_GT(rv, 0);
+      ASSERT_EQ(size, static_cast<size_t>(rv));
+      ++sent;
+    } while (sent < count);
+  }
+
+  int SendInvalidSrtpPacket(size_t channel, size_t size) {
+    ASSERT(channel < channels_.size());
+    rtc::scoped_ptr<char[]> packet(new char[size]);
+    // Fill the packet with 0 to form an invalid SRTP packet.
+    memset(packet.get(), 0, size);
+
+    rtc::PacketOptions packet_options;
+    return channels_[channel]->SendPacket(
+        packet.get(), size, packet_options, cricket::PF_SRTP_BYPASS);
+  }
+
+  void ExpectPackets(size_t channel, size_t size) {
+    packet_size_ = size;
+    received_.clear();
+  }
+
+  size_t NumPacketsReceived() {
+    return received_.size();
+  }
+
+  bool VerifyPacket(const char* data, size_t size, uint32* out_num) {
+    if (size != packet_size_ ||
+        (data[0] != 0 && static_cast<uint8>(data[0]) != 0x80)) {
+      return false;
+    }
+    uint32 packet_num = rtc::GetBE32(data + kPacketNumOffset);
+    for (size_t i = kPacketHeaderLen; i < size; ++i) {
+      if (static_cast<uint8>(data[i]) != (packet_num & 0xff)) {
+        return false;
+      }
+    }
+    if (out_num) {
+      *out_num = packet_num;
+    }
+    return true;
+  }
+  bool VerifyEncryptedPacket(const char* data, size_t size) {
+    // This is an encrypted data packet; let's make sure it's mostly random;
+    // less than 10% of the bytes should be equal to the cleartext packet.
+    if (size <= packet_size_) {
+      return false;
+    }
+    uint32 packet_num = rtc::GetBE32(data + kPacketNumOffset);
+    int num_matches = 0;
+    for (size_t i = kPacketNumOffset; i < size; ++i) {
+      if (static_cast<uint8>(data[i]) == (packet_num & 0xff)) {
+        ++num_matches;
+      }
+    }
+    return (num_matches < ((static_cast<int>(size) - 5) / 10));
+  }
+
+  // Transport callbacks
+  void OnTransportWritableState(cricket::Transport* transport) {
+    LOG(LS_INFO) << name_ << ": is writable";
+  }
+
+  // Transport channel callbacks
+  void OnTransportChannelWritableState(cricket::TransportChannel* channel) {
+    LOG(LS_INFO) << name_ << ": Channel '" << channel->component()
+                 << "' is writable";
+  }
+
+  void OnTransportChannelReadPacket(cricket::TransportChannel* channel,
+                                    const char* data, size_t size,
+                                    const rtc::PacketTime& packet_time,
+                                    int flags) {
+    uint32 packet_num = 0;
+    ASSERT_TRUE(VerifyPacket(data, size, &packet_num));
+    received_.insert(packet_num);
+    // Only DTLS-SRTP packets should have the bypass flag set.
+    int expected_flags = (identity_.get() && IsRtpLeadByte(data[0])) ?
+        cricket::PF_SRTP_BYPASS : 0;
+    ASSERT_EQ(expected_flags, flags);
+  }
+
+  // Hook into the raw packet stream to make sure DTLS packets are encrypted.
+  void OnFakeTransportChannelReadPacket(cricket::TransportChannel* channel,
+                                        const char* data, size_t size,
+                                        const rtc::PacketTime& time,
+                                        int flags) {
+    // Flags shouldn't be set on the underlying TransportChannel packets.
+    ASSERT_EQ(0, flags);
+
+    // Look at the handshake packets to see what role we played.
+    // Check that non-handshake packets are DTLS data or SRTP bypass.
+    if (negotiated_dtls_) {
+      if (data[0] == 22 && size > 17) {
+        if (data[13] == 1) {
+          received_dtls_client_hello_ = true;
+        } else if (data[13] == 2) {
+          received_dtls_server_hello_ = true;
+        }
+      } else if (!(data[0] >= 20 && data[0] <= 22)) {
+        ASSERT_TRUE(data[0] == 23 || IsRtpLeadByte(data[0]));
+        if (data[0] == 23) {
+          ASSERT_TRUE(VerifyEncryptedPacket(data, size));
+        } else if (IsRtpLeadByte(data[0])) {
+          ASSERT_TRUE(VerifyPacket(data, size, NULL));
+        }
+      }
+    }
+  }
+
+ private:
+  std::string name_;
+  rtc::Thread* signaling_thread_;
+  rtc::Thread* worker_thread_;
+  cricket::TransportProtocol protocol_;
+  rtc::scoped_ptr<rtc::SSLIdentity> identity_;
+  rtc::scoped_ptr<cricket::FakeTransport> transport_;
+  std::vector<cricket::DtlsTransportChannelWrapper*> channels_;
+  size_t packet_size_;
+  std::set<int> received_;
+  bool use_dtls_srtp_;
+  bool negotiated_dtls_;
+  bool received_dtls_client_hello_;
+  bool received_dtls_server_hello_;
+};
+
+
+class DtlsTransportChannelTest : public testing::Test {
+ public:
+  DtlsTransportChannelTest() :
+      client1_("P1", rtc::Thread::Current(),
+               rtc::Thread::Current()),
+      client2_("P2", rtc::Thread::Current(),
+               rtc::Thread::Current()),
+      channel_ct_(1),
+      use_dtls_(false),
+      use_dtls_srtp_(false) {
+  }
+
+  void SetChannelCount(size_t channel_ct) {
+    channel_ct_ = static_cast<int>(channel_ct);
+  }
+  void PrepareDtls(bool c1, bool c2) {
+    if (c1) {
+      client1_.CreateIdentity();
+    }
+    if (c2) {
+      client2_.CreateIdentity();
+    }
+    if (c1 && c2)
+      use_dtls_ = true;
+  }
+  void PrepareDtlsSrtp(bool c1, bool c2) {
+    if (!use_dtls_)
+      return;
+
+    if (c1)
+      client1_.SetupSrtp();
+    if (c2)
+      client2_.SetupSrtp();
+
+    if (c1 && c2)
+      use_dtls_srtp_ = true;
+  }
+
+  bool Connect(ConnectionRole client1_role, ConnectionRole client2_role) {
+    Negotiate(client1_role, client2_role);
+
+    bool rv = client1_.Connect(&client2_);
+    EXPECT_TRUE(rv);
+    if (!rv)
+      return false;
+
+    EXPECT_TRUE_WAIT(client1_.writable() && client2_.writable(), 10000);
+    if (!client1_.writable() || !client2_.writable())
+      return false;
+
+    // Check that we used the right roles.
+    if (use_dtls_) {
+      rtc::SSLRole client1_ssl_role =
+          (client1_role == cricket::CONNECTIONROLE_ACTIVE ||
+           (client2_role == cricket::CONNECTIONROLE_PASSIVE &&
+            client1_role == cricket::CONNECTIONROLE_ACTPASS)) ?
+              rtc::SSL_CLIENT : rtc::SSL_SERVER;
+
+      rtc::SSLRole client2_ssl_role =
+          (client2_role == cricket::CONNECTIONROLE_ACTIVE ||
+           (client1_role == cricket::CONNECTIONROLE_PASSIVE &&
+            client2_role == cricket::CONNECTIONROLE_ACTPASS)) ?
+              rtc::SSL_CLIENT : rtc::SSL_SERVER;
+
+      client1_.CheckRole(client1_ssl_role);
+      client2_.CheckRole(client2_ssl_role);
+    }
+
+    // Check that we negotiated the right ciphers.
+    if (use_dtls_srtp_) {
+      client1_.CheckSrtp(AES_CM_128_HMAC_SHA1_80);
+      client2_.CheckSrtp(AES_CM_128_HMAC_SHA1_80);
+    } else {
+      client1_.CheckSrtp("");
+      client2_.CheckSrtp("");
+    }
+
+    return true;
+  }
+
+  bool Connect() {
+    // By default, Client1 will be Server and Client2 will be Client.
+    return Connect(cricket::CONNECTIONROLE_ACTPASS,
+                   cricket::CONNECTIONROLE_ACTIVE);
+  }
+
+  void Negotiate() {
+    Negotiate(cricket::CONNECTIONROLE_ACTPASS, cricket::CONNECTIONROLE_ACTIVE);
+  }
+
+  void Negotiate(ConnectionRole client1_role, ConnectionRole client2_role) {
+    client1_.SetupChannels(channel_ct_, cricket::ICEROLE_CONTROLLING);
+    client2_.SetupChannels(channel_ct_, cricket::ICEROLE_CONTROLLED);
+    // Expect success from SLTD and SRTD.
+    client1_.Negotiate(&client2_, cricket::CA_OFFER,
+                       client1_role, client2_role, 0);
+    client2_.Negotiate(&client1_, cricket::CA_ANSWER,
+                       client2_role, client1_role, 0);
+  }
+
+  // Negotiate with legacy client |client2|. Legacy client doesn't use setup
+  // attributes, except NONE.
+  void NegotiateWithLegacy() {
+    client1_.SetupChannels(channel_ct_, cricket::ICEROLE_CONTROLLING);
+    client2_.SetupChannels(channel_ct_, cricket::ICEROLE_CONTROLLED);
+    // Expect success from SLTD and SRTD.
+    client1_.Negotiate(&client2_, cricket::CA_OFFER,
+                       cricket::CONNECTIONROLE_ACTPASS,
+                       cricket::CONNECTIONROLE_NONE, 0);
+    client2_.Negotiate(&client1_, cricket::CA_ANSWER,
+                       cricket::CONNECTIONROLE_ACTIVE,
+                       cricket::CONNECTIONROLE_NONE, 0);
+  }
+
+  void Renegotiate(DtlsTestClient* reoffer_initiator,
+                   ConnectionRole client1_role, ConnectionRole client2_role,
+                   int flags) {
+    if (reoffer_initiator == &client1_) {
+      client1_.Negotiate(&client2_, cricket::CA_OFFER,
+                         client1_role, client2_role, flags);
+      client2_.Negotiate(&client1_, cricket::CA_ANSWER,
+                         client2_role, client1_role, flags);
+    } else {
+      client2_.Negotiate(&client1_, cricket::CA_OFFER,
+                         client2_role, client1_role, flags);
+      client1_.Negotiate(&client2_, cricket::CA_ANSWER,
+                         client1_role, client2_role, flags);
+    }
+  }
+
+  void TestTransfer(size_t channel, size_t size, size_t count, bool srtp) {
+    LOG(LS_INFO) << "Expect packets, size=" << size;
+    client2_.ExpectPackets(channel, size);
+    client1_.SendPackets(channel, size, count, srtp);
+    EXPECT_EQ_WAIT(count, client2_.NumPacketsReceived(), 10000);
+  }
+
+ protected:
+  DtlsTestClient client1_;
+  DtlsTestClient client2_;
+  int channel_ct_;
+  bool use_dtls_;
+  bool use_dtls_srtp_;
+};
+
+// Test that transport negotiation of ICE, no DTLS works properly.
+TEST_F(DtlsTransportChannelTest, TestChannelSetupIce) {
+  client1_.SetIceProtocol(cricket::ICEPROTO_RFC5245);
+  client2_.SetIceProtocol(cricket::ICEPROTO_RFC5245);
+  Negotiate();
+  cricket::FakeTransportChannel* channel1 = client1_.GetFakeChannel(0);
+  cricket::FakeTransportChannel* channel2 = client2_.GetFakeChannel(0);
+  ASSERT_TRUE(channel1 != NULL);
+  ASSERT_TRUE(channel2 != NULL);
+  EXPECT_EQ(cricket::ICEROLE_CONTROLLING, channel1->GetIceRole());
+  EXPECT_EQ(1U, channel1->IceTiebreaker());
+  EXPECT_EQ(cricket::ICEPROTO_RFC5245, channel1->protocol());
+  EXPECT_EQ(kIceUfrag1, channel1->ice_ufrag());
+  EXPECT_EQ(kIcePwd1, channel1->ice_pwd());
+  EXPECT_EQ(cricket::ICEROLE_CONTROLLED, channel2->GetIceRole());
+  EXPECT_EQ(2U, channel2->IceTiebreaker());
+  EXPECT_EQ(cricket::ICEPROTO_RFC5245, channel2->protocol());
+}
+
+// Test that transport negotiation of GICE, no DTLS works properly.
+TEST_F(DtlsTransportChannelTest, TestChannelSetupGice) {
+  client1_.SetIceProtocol(cricket::ICEPROTO_GOOGLE);
+  client2_.SetIceProtocol(cricket::ICEPROTO_GOOGLE);
+  Negotiate();
+  cricket::FakeTransportChannel* channel1 = client1_.GetFakeChannel(0);
+  cricket::FakeTransportChannel* channel2 = client2_.GetFakeChannel(0);
+  ASSERT_TRUE(channel1 != NULL);
+  ASSERT_TRUE(channel2 != NULL);
+  EXPECT_EQ(cricket::ICEROLE_CONTROLLING, channel1->GetIceRole());
+  EXPECT_EQ(1U, channel1->IceTiebreaker());
+  EXPECT_EQ(cricket::ICEPROTO_GOOGLE, channel1->protocol());
+  EXPECT_EQ(kIceUfrag1, channel1->ice_ufrag());
+  EXPECT_EQ(kIcePwd1, channel1->ice_pwd());
+  EXPECT_EQ(cricket::ICEROLE_CONTROLLED, channel2->GetIceRole());
+  EXPECT_EQ(2U, channel2->IceTiebreaker());
+  EXPECT_EQ(cricket::ICEPROTO_GOOGLE, channel2->protocol());
+}
+
+// Connect without DTLS, and transfer some data.
+TEST_F(DtlsTransportChannelTest, TestTransfer) {
+  ASSERT_TRUE(Connect());
+  TestTransfer(0, 1000, 100, false);
+}
+
+// Create two channels without DTLS, and transfer some data.
+TEST_F(DtlsTransportChannelTest, TestTransferTwoChannels) {
+  SetChannelCount(2);
+  ASSERT_TRUE(Connect());
+  TestTransfer(0, 1000, 100, false);
+  TestTransfer(1, 1000, 100, false);
+}
+
+// Connect without DTLS, and transfer SRTP data.
+TEST_F(DtlsTransportChannelTest, TestTransferSrtp) {
+  ASSERT_TRUE(Connect());
+  TestTransfer(0, 1000, 100, true);
+}
+
+// Create two channels without DTLS, and transfer SRTP data.
+TEST_F(DtlsTransportChannelTest, TestTransferSrtpTwoChannels) {
+  SetChannelCount(2);
+  ASSERT_TRUE(Connect());
+  TestTransfer(0, 1000, 100, true);
+  TestTransfer(1, 1000, 100, true);
+}
+
+// Connect with DTLS, and transfer some data.
+TEST_F(DtlsTransportChannelTest, TestTransferDtls) {
+  MAYBE_SKIP_TEST(HaveDtls);
+  PrepareDtls(true, true);
+  ASSERT_TRUE(Connect());
+  TestTransfer(0, 1000, 100, false);
+}
+
+// Create two channels with DTLS, and transfer some data.
+TEST_F(DtlsTransportChannelTest, TestTransferDtlsTwoChannels) {
+  MAYBE_SKIP_TEST(HaveDtls);
+  SetChannelCount(2);
+  PrepareDtls(true, true);
+  ASSERT_TRUE(Connect());
+  TestTransfer(0, 1000, 100, false);
+  TestTransfer(1, 1000, 100, false);
+}
+
+// Connect with A doing DTLS and B not, and transfer some data.
+TEST_F(DtlsTransportChannelTest, TestTransferDtlsRejected) {
+  PrepareDtls(true, false);
+  ASSERT_TRUE(Connect());
+  TestTransfer(0, 1000, 100, false);
+}
+
+// Connect with B doing DTLS and A not, and transfer some data.
+TEST_F(DtlsTransportChannelTest, TestTransferDtlsNotOffered) {
+  PrepareDtls(false, true);
+  ASSERT_TRUE(Connect());
+  TestTransfer(0, 1000, 100, false);
+}
+
+// Connect with DTLS, negotiate DTLS-SRTP, and transfer SRTP using bypass.
+TEST_F(DtlsTransportChannelTest, TestTransferDtlsSrtp) {
+  MAYBE_SKIP_TEST(HaveDtlsSrtp);
+  PrepareDtls(true, true);
+  PrepareDtlsSrtp(true, true);
+  ASSERT_TRUE(Connect());
+  TestTransfer(0, 1000, 100, true);
+}
+
+// Connect with DTLS-SRTP, transfer an invalid SRTP packet, and expects -1
+// returned.
+TEST_F(DtlsTransportChannelTest, TestTransferDtlsInvalidSrtpPacket) {
+  MAYBE_SKIP_TEST(HaveDtls);
+  PrepareDtls(true, true);
+  PrepareDtlsSrtp(true, true);
+  ASSERT_TRUE(Connect());
+  int result = client1_.SendInvalidSrtpPacket(0, 100);
+  ASSERT_EQ(-1, result);
+}
+
+// Connect with DTLS. A does DTLS-SRTP but B does not.
+TEST_F(DtlsTransportChannelTest, TestTransferDtlsSrtpRejected) {
+  MAYBE_SKIP_TEST(HaveDtlsSrtp);
+  PrepareDtls(true, true);
+  PrepareDtlsSrtp(true, false);
+  ASSERT_TRUE(Connect());
+}
+
+// Connect with DTLS. B does DTLS-SRTP but A does not.
+TEST_F(DtlsTransportChannelTest, TestTransferDtlsSrtpNotOffered) {
+  MAYBE_SKIP_TEST(HaveDtlsSrtp);
+  PrepareDtls(true, true);
+  PrepareDtlsSrtp(false, true);
+  ASSERT_TRUE(Connect());
+}
+
+// Create two channels with DTLS, negotiate DTLS-SRTP, and transfer bypass SRTP.
+TEST_F(DtlsTransportChannelTest, TestTransferDtlsSrtpTwoChannels) {
+  MAYBE_SKIP_TEST(HaveDtlsSrtp);
+  SetChannelCount(2);
+  PrepareDtls(true, true);
+  PrepareDtlsSrtp(true, true);
+  ASSERT_TRUE(Connect());
+  TestTransfer(0, 1000, 100, true);
+  TestTransfer(1, 1000, 100, true);
+}
+
+// Create a single channel with DTLS, and send normal data and SRTP data on it.
+TEST_F(DtlsTransportChannelTest, TestTransferDtlsSrtpDemux) {
+  MAYBE_SKIP_TEST(HaveDtlsSrtp);
+  PrepareDtls(true, true);
+  PrepareDtlsSrtp(true, true);
+  ASSERT_TRUE(Connect());
+  TestTransfer(0, 1000, 100, false);
+  TestTransfer(0, 1000, 100, true);
+}
+
+// Testing when the remote is passive.
+TEST_F(DtlsTransportChannelTest, TestTransferDtlsAnswererIsPassive) {
+  MAYBE_SKIP_TEST(HaveDtlsSrtp);
+  SetChannelCount(2);
+  PrepareDtls(true, true);
+  PrepareDtlsSrtp(true, true);
+  ASSERT_TRUE(Connect(cricket::CONNECTIONROLE_ACTPASS,
+                      cricket::CONNECTIONROLE_PASSIVE));
+  TestTransfer(0, 1000, 100, true);
+  TestTransfer(1, 1000, 100, true);
+}
+
+// Testing with the legacy DTLS client which doesn't use setup attribute.
+// In this case legacy is the answerer.
+TEST_F(DtlsTransportChannelTest, TestDtlsSetupWithLegacyAsAnswerer) {
+  MAYBE_SKIP_TEST(HaveDtlsSrtp);
+  PrepareDtls(true, true);
+  NegotiateWithLegacy();
+  rtc::SSLRole channel1_role;
+  rtc::SSLRole channel2_role;
+  EXPECT_TRUE(client1_.transport()->GetSslRole(&channel1_role));
+  EXPECT_TRUE(client2_.transport()->GetSslRole(&channel2_role));
+  EXPECT_EQ(rtc::SSL_SERVER, channel1_role);
+  EXPECT_EQ(rtc::SSL_CLIENT, channel2_role);
+}
+
+// Testing re offer/answer after the session is estbalished. Roles will be
+// kept same as of the previous negotiation.
+TEST_F(DtlsTransportChannelTest, TestDtlsReOfferFromOfferer) {
+  MAYBE_SKIP_TEST(HaveDtlsSrtp);
+  SetChannelCount(2);
+  PrepareDtls(true, true);
+  PrepareDtlsSrtp(true, true);
+  // Initial role for client1 is ACTPASS and client2 is ACTIVE.
+  ASSERT_TRUE(Connect(cricket::CONNECTIONROLE_ACTPASS,
+                      cricket::CONNECTIONROLE_ACTIVE));
+  TestTransfer(0, 1000, 100, true);
+  TestTransfer(1, 1000, 100, true);
+  // Using input roles for the re-offer.
+  Renegotiate(&client1_, cricket::CONNECTIONROLE_ACTPASS,
+              cricket::CONNECTIONROLE_ACTIVE, NF_REOFFER);
+  TestTransfer(0, 1000, 100, true);
+  TestTransfer(1, 1000, 100, true);
+}
+
+TEST_F(DtlsTransportChannelTest, TestDtlsReOfferFromAnswerer) {
+  MAYBE_SKIP_TEST(HaveDtlsSrtp);
+  SetChannelCount(2);
+  PrepareDtls(true, true);
+  PrepareDtlsSrtp(true, true);
+  // Initial role for client1 is ACTPASS and client2 is ACTIVE.
+  ASSERT_TRUE(Connect(cricket::CONNECTIONROLE_ACTPASS,
+                      cricket::CONNECTIONROLE_ACTIVE));
+  TestTransfer(0, 1000, 100, true);
+  TestTransfer(1, 1000, 100, true);
+  // Using input roles for the re-offer.
+  Renegotiate(&client2_, cricket::CONNECTIONROLE_PASSIVE,
+              cricket::CONNECTIONROLE_ACTPASS, NF_REOFFER);
+  TestTransfer(0, 1000, 100, true);
+  TestTransfer(1, 1000, 100, true);
+}
+
+// Test that any change in role after the intial setup will result in failure.
+TEST_F(DtlsTransportChannelTest, TestDtlsRoleReversal) {
+  MAYBE_SKIP_TEST(HaveDtlsSrtp);
+  SetChannelCount(2);
+  PrepareDtls(true, true);
+  PrepareDtlsSrtp(true, true);
+  ASSERT_TRUE(Connect(cricket::CONNECTIONROLE_ACTPASS,
+                      cricket::CONNECTIONROLE_PASSIVE));
+
+  // Renegotiate from client2 with actpass and client1 as active.
+  Renegotiate(&client2_, cricket::CONNECTIONROLE_ACTPASS,
+              cricket::CONNECTIONROLE_ACTIVE,
+              NF_REOFFER | NF_EXPECT_FAILURE);
+}
+
+// Test that using different setup attributes which results in similar ssl
+// role as the initial negotiation will result in success.
+TEST_F(DtlsTransportChannelTest, TestDtlsReOfferWithDifferentSetupAttr) {
+  MAYBE_SKIP_TEST(HaveDtlsSrtp);
+  SetChannelCount(2);
+  PrepareDtls(true, true);
+  PrepareDtlsSrtp(true, true);
+  ASSERT_TRUE(Connect(cricket::CONNECTIONROLE_ACTPASS,
+                      cricket::CONNECTIONROLE_PASSIVE));
+  // Renegotiate from client2 with actpass and client1 as active.
+  Renegotiate(&client2_, cricket::CONNECTIONROLE_ACTIVE,
+              cricket::CONNECTIONROLE_ACTPASS, NF_REOFFER);
+  TestTransfer(0, 1000, 100, true);
+  TestTransfer(1, 1000, 100, true);
+}
+
+// Test that re-negotiation can be started before the clients become connected
+// in the first negotiation.
+TEST_F(DtlsTransportChannelTest, TestRenegotiateBeforeConnect) {
+  MAYBE_SKIP_TEST(HaveDtlsSrtp);
+  SetChannelCount(2);
+  PrepareDtls(true, true);
+  PrepareDtlsSrtp(true, true);
+  Negotiate();
+
+  Renegotiate(&client1_, cricket::CONNECTIONROLE_ACTPASS,
+              cricket::CONNECTIONROLE_ACTIVE, NF_REOFFER);
+  bool rv = client1_.Connect(&client2_);
+  EXPECT_TRUE(rv);
+  EXPECT_TRUE_WAIT(client1_.writable() && client2_.writable(), 10000);
+
+  TestTransfer(0, 1000, 100, true);
+  TestTransfer(1, 1000, 100, true);
+}
+
+// Test Certificates state after negotiation but before connection.
+TEST_F(DtlsTransportChannelTest, TestCertificatesBeforeConnect) {
+  MAYBE_SKIP_TEST(HaveDtls);
+  PrepareDtls(true, true);
+  Negotiate();
+
+  rtc::scoped_ptr<rtc::SSLIdentity> identity1;
+  rtc::scoped_ptr<rtc::SSLIdentity> identity2;
+  rtc::scoped_ptr<rtc::SSLCertificate> remote_cert1;
+  rtc::scoped_ptr<rtc::SSLCertificate> remote_cert2;
+
+  // After negotiation, each side has a distinct local certificate, but still no
+  // remote certificate, because connection has not yet occurred.
+  ASSERT_TRUE(client1_.transport()->GetIdentity(identity1.accept()));
+  ASSERT_TRUE(client2_.transport()->GetIdentity(identity2.accept()));
+  ASSERT_NE(identity1->certificate().ToPEMString(),
+            identity2->certificate().ToPEMString());
+  ASSERT_FALSE(
+      client1_.transport()->GetRemoteCertificate(remote_cert1.accept()));
+  ASSERT_FALSE(remote_cert1 != NULL);
+  ASSERT_FALSE(
+      client2_.transport()->GetRemoteCertificate(remote_cert2.accept()));
+  ASSERT_FALSE(remote_cert2 != NULL);
+}
+
+// Test Certificates state after connection.
+TEST_F(DtlsTransportChannelTest, TestCertificatesAfterConnect) {
+  MAYBE_SKIP_TEST(HaveDtls);
+  PrepareDtls(true, true);
+  ASSERT_TRUE(Connect());
+
+  rtc::scoped_ptr<rtc::SSLIdentity> identity1;
+  rtc::scoped_ptr<rtc::SSLIdentity> identity2;
+  rtc::scoped_ptr<rtc::SSLCertificate> remote_cert1;
+  rtc::scoped_ptr<rtc::SSLCertificate> remote_cert2;
+
+  // After connection, each side has a distinct local certificate.
+  ASSERT_TRUE(client1_.transport()->GetIdentity(identity1.accept()));
+  ASSERT_TRUE(client2_.transport()->GetIdentity(identity2.accept()));
+  ASSERT_NE(identity1->certificate().ToPEMString(),
+            identity2->certificate().ToPEMString());
+
+  // Each side's remote certificate is the other side's local certificate.
+  ASSERT_TRUE(
+      client1_.transport()->GetRemoteCertificate(remote_cert1.accept()));
+  ASSERT_EQ(remote_cert1->ToPEMString(),
+            identity2->certificate().ToPEMString());
+  ASSERT_TRUE(
+      client2_.transport()->GetRemoteCertificate(remote_cert2.accept()));
+  ASSERT_EQ(remote_cert2->ToPEMString(),
+            identity1->certificate().ToPEMString());
+}
diff --git a/webrtc/p2p/base/fakesession.h b/webrtc/p2p/base/fakesession.h
new file mode 100644
index 0000000..30bc981
--- /dev/null
+++ b/webrtc/p2p/base/fakesession.h
@@ -0,0 +1,492 @@
+/*
+ *  Copyright 2009 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_FAKESESSION_H_
+#define WEBRTC_P2P_BASE_FAKESESSION_H_
+
+#include <map>
+#include <string>
+#include <vector>
+
+#include "webrtc/p2p/base/session.h"
+#include "webrtc/p2p/base/transport.h"
+#include "webrtc/p2p/base/transportchannel.h"
+#include "webrtc/p2p/base/transportchannelimpl.h"
+#include "webrtc/base/buffer.h"
+#include "webrtc/base/fakesslidentity.h"
+#include "webrtc/base/messagequeue.h"
+#include "webrtc/base/sigslot.h"
+#include "webrtc/base/sslfingerprint.h"
+
+namespace cricket {
+
+class FakeTransport;
+
+struct PacketMessageData : public rtc::MessageData {
+  PacketMessageData(const char* data, size_t len) : packet(data, len) {
+  }
+  rtc::Buffer packet;
+};
+
+// Fake transport channel class, which can be passed to anything that needs a
+// transport channel. Can be informed of another FakeTransportChannel via
+// SetDestination.
+class FakeTransportChannel : public TransportChannelImpl,
+                             public rtc::MessageHandler {
+ public:
+  explicit FakeTransportChannel(Transport* transport,
+                                const std::string& content_name,
+                                int component)
+      : TransportChannelImpl(content_name, component),
+        transport_(transport),
+        dest_(NULL),
+        state_(STATE_INIT),
+        async_(false),
+        identity_(NULL),
+        do_dtls_(false),
+        role_(ICEROLE_UNKNOWN),
+        tiebreaker_(0),
+        ice_proto_(ICEPROTO_HYBRID),
+        remote_ice_mode_(ICEMODE_FULL),
+        dtls_fingerprint_("", NULL, 0),
+        ssl_role_(rtc::SSL_CLIENT),
+        connection_count_(0) {
+  }
+  ~FakeTransportChannel() {
+    Reset();
+  }
+
+  uint64 IceTiebreaker() const { return tiebreaker_; }
+  TransportProtocol protocol() const { return ice_proto_; }
+  IceMode remote_ice_mode() const { return remote_ice_mode_; }
+  const std::string& ice_ufrag() const { return ice_ufrag_; }
+  const std::string& ice_pwd() const { return ice_pwd_; }
+  const std::string& remote_ice_ufrag() const { return remote_ice_ufrag_; }
+  const std::string& remote_ice_pwd() const { return remote_ice_pwd_; }
+  const rtc::SSLFingerprint& dtls_fingerprint() const {
+    return dtls_fingerprint_;
+  }
+
+  void SetAsync(bool async) {
+    async_ = async;
+  }
+
+  virtual Transport* GetTransport() {
+    return transport_;
+  }
+
+  virtual void SetIceRole(IceRole role) { role_ = role; }
+  virtual IceRole GetIceRole() const { return role_; }
+  virtual size_t GetConnectionCount() const { return connection_count_; }
+  virtual void SetIceTiebreaker(uint64 tiebreaker) { tiebreaker_ = tiebreaker; }
+  virtual bool GetIceProtocolType(IceProtocolType* type) const {
+    *type = ice_proto_;
+    return true;
+  }
+  virtual void SetIceProtocolType(IceProtocolType type) { ice_proto_ = type; }
+  virtual void SetIceCredentials(const std::string& ice_ufrag,
+                                 const std::string& ice_pwd) {
+    ice_ufrag_ = ice_ufrag;
+    ice_pwd_ = ice_pwd;
+  }
+  virtual void SetRemoteIceCredentials(const std::string& ice_ufrag,
+                                       const std::string& ice_pwd) {
+    remote_ice_ufrag_ = ice_ufrag;
+    remote_ice_pwd_ = ice_pwd;
+  }
+
+  virtual void SetRemoteIceMode(IceMode mode) { remote_ice_mode_ = mode; }
+  virtual bool SetRemoteFingerprint(const std::string& alg, const uint8* digest,
+                                    size_t digest_len) {
+    dtls_fingerprint_ = rtc::SSLFingerprint(alg, digest, digest_len);
+    return true;
+  }
+  virtual bool SetSslRole(rtc::SSLRole role) {
+    ssl_role_ = role;
+    return true;
+  }
+  virtual bool GetSslRole(rtc::SSLRole* role) const {
+    *role = ssl_role_;
+    return true;
+  }
+
+  virtual void Connect() {
+    if (state_ == STATE_INIT) {
+      state_ = STATE_CONNECTING;
+    }
+  }
+  virtual void Reset() {
+    if (state_ != STATE_INIT) {
+      state_ = STATE_INIT;
+      if (dest_) {
+        dest_->state_ = STATE_INIT;
+        dest_->dest_ = NULL;
+        dest_ = NULL;
+      }
+    }
+  }
+
+  void SetWritable(bool writable) {
+    set_writable(writable);
+  }
+
+  void SetDestination(FakeTransportChannel* dest) {
+    if (state_ == STATE_CONNECTING && dest) {
+      // This simulates the delivery of candidates.
+      dest_ = dest;
+      dest_->dest_ = this;
+      if (identity_ && dest_->identity_) {
+        do_dtls_ = true;
+        dest_->do_dtls_ = true;
+        NegotiateSrtpCiphers();
+      }
+      state_ = STATE_CONNECTED;
+      dest_->state_ = STATE_CONNECTED;
+      set_writable(true);
+      dest_->set_writable(true);
+    } else if (state_ == STATE_CONNECTED && !dest) {
+      // Simulates loss of connectivity, by asymmetrically forgetting dest_.
+      dest_ = NULL;
+      state_ = STATE_CONNECTING;
+      set_writable(false);
+    }
+  }
+
+  void SetConnectionCount(size_t connection_count) {
+    size_t old_connection_count = connection_count_;
+    connection_count_ = connection_count;
+    if (connection_count_ < old_connection_count)
+      SignalConnectionRemoved(this);
+  }
+
+  virtual int SendPacket(const char* data, size_t len,
+                         const rtc::PacketOptions& options, int flags) {
+    if (state_ != STATE_CONNECTED) {
+      return -1;
+    }
+
+    if (flags != PF_SRTP_BYPASS && flags != 0) {
+      return -1;
+    }
+
+    PacketMessageData* packet = new PacketMessageData(data, len);
+    if (async_) {
+      rtc::Thread::Current()->Post(this, 0, packet);
+    } else {
+      rtc::Thread::Current()->Send(this, 0, packet);
+    }
+    return static_cast<int>(len);
+  }
+  virtual int SetOption(rtc::Socket::Option opt, int value) {
+    return true;
+  }
+  virtual int GetError() {
+    return 0;
+  }
+
+  virtual void OnSignalingReady() {
+  }
+  virtual void OnCandidate(const Candidate& candidate) {
+  }
+
+  virtual void OnMessage(rtc::Message* msg) {
+    PacketMessageData* data = static_cast<PacketMessageData*>(
+        msg->pdata);
+    dest_->SignalReadPacket(dest_, data->packet.data(),
+                            data->packet.length(),
+                            rtc::CreatePacketTime(0), 0);
+    delete data;
+  }
+
+  bool SetLocalIdentity(rtc::SSLIdentity* identity) {
+    identity_ = identity;
+    return true;
+  }
+
+
+  void SetRemoteCertificate(rtc::FakeSSLCertificate* cert) {
+    remote_cert_ = cert;
+  }
+
+  virtual bool IsDtlsActive() const {
+    return do_dtls_;
+  }
+
+  virtual bool SetSrtpCiphers(const std::vector<std::string>& ciphers) {
+    srtp_ciphers_ = ciphers;
+    return true;
+  }
+
+  virtual bool GetSrtpCipher(std::string* cipher) {
+    if (!chosen_srtp_cipher_.empty()) {
+      *cipher = chosen_srtp_cipher_;
+      return true;
+    }
+    return false;
+  }
+
+  virtual bool GetLocalIdentity(rtc::SSLIdentity** identity) const {
+    if (!identity_)
+      return false;
+
+    *identity = identity_->GetReference();
+    return true;
+  }
+
+  virtual bool GetRemoteCertificate(rtc::SSLCertificate** cert) const {
+    if (!remote_cert_)
+      return false;
+
+    *cert = remote_cert_->GetReference();
+    return true;
+  }
+
+  virtual bool ExportKeyingMaterial(const std::string& label,
+                                    const uint8* context,
+                                    size_t context_len,
+                                    bool use_context,
+                                    uint8* result,
+                                    size_t result_len) {
+    if (!chosen_srtp_cipher_.empty()) {
+      memset(result, 0xff, result_len);
+      return true;
+    }
+
+    return false;
+  }
+
+  virtual void NegotiateSrtpCiphers() {
+    for (std::vector<std::string>::const_iterator it1 = srtp_ciphers_.begin();
+        it1 != srtp_ciphers_.end(); ++it1) {
+      for (std::vector<std::string>::const_iterator it2 =
+              dest_->srtp_ciphers_.begin();
+          it2 != dest_->srtp_ciphers_.end(); ++it2) {
+        if (*it1 == *it2) {
+          chosen_srtp_cipher_ = *it1;
+          dest_->chosen_srtp_cipher_ = *it2;
+          return;
+        }
+      }
+    }
+  }
+
+  virtual bool GetStats(ConnectionInfos* infos) OVERRIDE {
+    ConnectionInfo info;
+    infos->clear();
+    infos->push_back(info);
+    return true;
+  }
+
+ private:
+  enum State { STATE_INIT, STATE_CONNECTING, STATE_CONNECTED };
+  Transport* transport_;
+  FakeTransportChannel* dest_;
+  State state_;
+  bool async_;
+  rtc::SSLIdentity* identity_;
+  rtc::FakeSSLCertificate* remote_cert_;
+  bool do_dtls_;
+  std::vector<std::string> srtp_ciphers_;
+  std::string chosen_srtp_cipher_;
+  IceRole role_;
+  uint64 tiebreaker_;
+  IceProtocolType ice_proto_;
+  std::string ice_ufrag_;
+  std::string ice_pwd_;
+  std::string remote_ice_ufrag_;
+  std::string remote_ice_pwd_;
+  IceMode remote_ice_mode_;
+  rtc::SSLFingerprint dtls_fingerprint_;
+  rtc::SSLRole ssl_role_;
+  size_t connection_count_;
+};
+
+// Fake transport class, which can be passed to anything that needs a Transport.
+// Can be informed of another FakeTransport via SetDestination (low-tech way
+// of doing candidates)
+class FakeTransport : public Transport {
+ public:
+  typedef std::map<int, FakeTransportChannel*> ChannelMap;
+  FakeTransport(rtc::Thread* signaling_thread,
+                rtc::Thread* worker_thread,
+                const std::string& content_name,
+                PortAllocator* alllocator = NULL)
+      : Transport(signaling_thread, worker_thread,
+                  content_name, "test_type", NULL),
+      dest_(NULL),
+      async_(false),
+      identity_(NULL) {
+  }
+  ~FakeTransport() {
+    DestroyAllChannels();
+  }
+
+  const ChannelMap& channels() const { return channels_; }
+
+  void SetAsync(bool async) { async_ = async; }
+  void SetDestination(FakeTransport* dest) {
+    dest_ = dest;
+    for (ChannelMap::iterator it = channels_.begin(); it != channels_.end();
+         ++it) {
+      it->second->SetLocalIdentity(identity_);
+      SetChannelDestination(it->first, it->second);
+    }
+  }
+
+  void SetWritable(bool writable) {
+    for (ChannelMap::iterator it = channels_.begin(); it != channels_.end();
+         ++it) {
+      it->second->SetWritable(writable);
+    }
+  }
+
+  void set_identity(rtc::SSLIdentity* identity) {
+    identity_ = identity;
+  }
+
+  using Transport::local_description;
+  using Transport::remote_description;
+
+ protected:
+  virtual TransportChannelImpl* CreateTransportChannel(int component) {
+    if (channels_.find(component) != channels_.end()) {
+      return NULL;
+    }
+    FakeTransportChannel* channel =
+        new FakeTransportChannel(this, content_name(), component);
+    channel->SetAsync(async_);
+    SetChannelDestination(component, channel);
+    channels_[component] = channel;
+    return channel;
+  }
+  virtual void DestroyTransportChannel(TransportChannelImpl* channel) {
+    channels_.erase(channel->component());
+    delete channel;
+  }
+  virtual void SetIdentity_w(rtc::SSLIdentity* identity) {
+    identity_ = identity;
+  }
+  virtual bool GetIdentity_w(rtc::SSLIdentity** identity) {
+    if (!identity_)
+      return false;
+
+    *identity = identity_->GetReference();
+    return true;
+  }
+
+ private:
+  FakeTransportChannel* GetFakeChannel(int component) {
+    ChannelMap::iterator it = channels_.find(component);
+    return (it != channels_.end()) ? it->second : NULL;
+  }
+  void SetChannelDestination(int component,
+                             FakeTransportChannel* channel) {
+    FakeTransportChannel* dest_channel = NULL;
+    if (dest_) {
+      dest_channel = dest_->GetFakeChannel(component);
+      if (dest_channel) {
+        dest_channel->SetLocalIdentity(dest_->identity_);
+      }
+    }
+    channel->SetDestination(dest_channel);
+  }
+
+  // Note, this is distinct from the Channel map owned by Transport.
+  // This map just tracks the FakeTransportChannels created by this class.
+  ChannelMap channels_;
+  FakeTransport* dest_;
+  bool async_;
+  rtc::SSLIdentity* identity_;
+};
+
+// Fake session class, which can be passed into a BaseChannel object for
+// test purposes. Can be connected to other FakeSessions via Connect().
+class FakeSession : public BaseSession {
+ public:
+  explicit FakeSession()
+      : BaseSession(rtc::Thread::Current(),
+                    rtc::Thread::Current(),
+                    NULL, "", "", true),
+      fail_create_channel_(false) {
+  }
+  explicit FakeSession(bool initiator)
+      : BaseSession(rtc::Thread::Current(),
+                    rtc::Thread::Current(),
+                    NULL, "", "", initiator),
+      fail_create_channel_(false) {
+  }
+  FakeSession(rtc::Thread* worker_thread, bool initiator)
+      : BaseSession(rtc::Thread::Current(),
+                    worker_thread,
+                    NULL, "", "", initiator),
+      fail_create_channel_(false) {
+  }
+
+  FakeTransport* GetTransport(const std::string& content_name) {
+    return static_cast<FakeTransport*>(
+        BaseSession::GetTransport(content_name));
+  }
+
+  void Connect(FakeSession* dest) {
+    // Simulate the exchange of candidates.
+    CompleteNegotiation();
+    dest->CompleteNegotiation();
+    for (TransportMap::const_iterator it = transport_proxies().begin();
+        it != transport_proxies().end(); ++it) {
+      static_cast<FakeTransport*>(it->second->impl())->SetDestination(
+          dest->GetTransport(it->first));
+    }
+  }
+
+  virtual TransportChannel* CreateChannel(
+      const std::string& content_name,
+      const std::string& channel_name,
+      int component) {
+    if (fail_create_channel_) {
+      return NULL;
+    }
+    return BaseSession::CreateChannel(content_name, channel_name, component);
+  }
+
+  void set_fail_channel_creation(bool fail_channel_creation) {
+    fail_create_channel_ = fail_channel_creation;
+  }
+
+  // TODO: Hoist this into Session when we re-work the Session code.
+  void set_ssl_identity(rtc::SSLIdentity* identity) {
+    for (TransportMap::const_iterator it = transport_proxies().begin();
+        it != transport_proxies().end(); ++it) {
+      // We know that we have a FakeTransport*
+
+      static_cast<FakeTransport*>(it->second->impl())->set_identity
+          (identity);
+    }
+  }
+
+ protected:
+  virtual Transport* CreateTransport(const std::string& content_name) {
+    return new FakeTransport(signaling_thread(), worker_thread(), content_name);
+  }
+
+  void CompleteNegotiation() {
+    for (TransportMap::const_iterator it = transport_proxies().begin();
+        it != transport_proxies().end(); ++it) {
+      it->second->CompleteNegotiation();
+      it->second->ConnectChannels();
+    }
+  }
+
+ private:
+  bool fail_create_channel_;
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_FAKESESSION_H_
diff --git a/webrtc/p2p/base/p2ptransport.cc b/webrtc/p2p/base/p2ptransport.cc
new file mode 100644
index 0000000..e873756
--- /dev/null
+++ b/webrtc/p2p/base/p2ptransport.cc
@@ -0,0 +1,246 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/p2ptransport.h"
+
+#include <string>
+#include <vector>
+
+#include "webrtc/p2p/base/constants.h"
+#include "webrtc/p2p/base/p2ptransportchannel.h"
+#include "webrtc/p2p/base/parsing.h"
+#include "webrtc/p2p/base/sessionmanager.h"
+#include "webrtc/p2p/base/sessionmessages.h"
+#include "webrtc/libjingle/xmllite/qname.h"
+#include "webrtc/libjingle/xmllite/xmlelement.h"
+#include "webrtc/libjingle/xmpp/constants.h"
+#include "webrtc/base/base64.h"
+#include "webrtc/base/common.h"
+#include "webrtc/base/stringencode.h"
+#include "webrtc/base/stringutils.h"
+
+namespace {
+
+// Limits for GICE and ICE username sizes.
+const size_t kMaxGiceUsernameSize = 16;
+const size_t kMaxIceUsernameSize = 512;
+
+}  // namespace
+
+namespace cricket {
+
+static buzz::XmlElement* NewTransportElement(const std::string& name) {
+  return new buzz::XmlElement(buzz::QName(name, LN_TRANSPORT), true);
+}
+
+P2PTransport::P2PTransport(rtc::Thread* signaling_thread,
+                           rtc::Thread* worker_thread,
+                           const std::string& content_name,
+                           PortAllocator* allocator)
+    : Transport(signaling_thread, worker_thread,
+                content_name, NS_GINGLE_P2P, allocator) {
+}
+
+P2PTransport::~P2PTransport() {
+  DestroyAllChannels();
+}
+
+TransportChannelImpl* P2PTransport::CreateTransportChannel(int component) {
+  return new P2PTransportChannel(content_name(), component, this,
+                                 port_allocator());
+}
+
+void P2PTransport::DestroyTransportChannel(TransportChannelImpl* channel) {
+  delete channel;
+}
+
+bool P2PTransportParser::ParseTransportDescription(
+    const buzz::XmlElement* elem,
+    const CandidateTranslator* translator,
+    TransportDescription* desc,
+    ParseError* error) {
+  ASSERT(elem->Name().LocalPart() == LN_TRANSPORT);
+  desc->transport_type = elem->Name().Namespace();
+  if (desc->transport_type != NS_GINGLE_P2P)
+    return BadParse("Unsupported transport type", error);
+
+  for (const buzz::XmlElement* candidate_elem = elem->FirstElement();
+       candidate_elem != NULL;
+       candidate_elem = candidate_elem->NextElement()) {
+    // Only look at local part because the namespace might (eventually)
+    // be NS_GINGLE_P2P or NS_JINGLE_ICE_UDP.
+    if (candidate_elem->Name().LocalPart() == LN_CANDIDATE) {
+      Candidate candidate;
+      if (!ParseCandidate(ICEPROTO_GOOGLE, candidate_elem, translator,
+                          &candidate, error)) {
+        return false;
+      }
+
+      desc->candidates.push_back(candidate);
+    }
+  }
+  return true;
+}
+
+bool P2PTransportParser::WriteTransportDescription(
+    const TransportDescription& desc,
+    const CandidateTranslator* translator,
+    buzz::XmlElement** out_elem,
+    WriteError* error) {
+  TransportProtocol proto = TransportProtocolFromDescription(&desc);
+  rtc::scoped_ptr<buzz::XmlElement> trans_elem(
+      NewTransportElement(desc.transport_type));
+
+  // Fail if we get HYBRID or ICE right now.
+  // TODO(juberti): Add ICE and HYBRID serialization.
+  if (proto != ICEPROTO_GOOGLE) {
+    LOG(LS_ERROR) << "Failed to serialize non-GICE TransportDescription";
+    return false;
+  }
+
+  for (std::vector<Candidate>::const_iterator iter = desc.candidates.begin();
+       iter != desc.candidates.end(); ++iter) {
+    rtc::scoped_ptr<buzz::XmlElement> cand_elem(
+        new buzz::XmlElement(QN_GINGLE_P2P_CANDIDATE));
+    if (!WriteCandidate(proto, *iter, translator, cand_elem.get(), error)) {
+      return false;
+    }
+    trans_elem->AddElement(cand_elem.release());
+  }
+
+  *out_elem = trans_elem.release();
+  return true;
+}
+
+bool P2PTransportParser::ParseGingleCandidate(
+    const buzz::XmlElement* elem,
+    const CandidateTranslator* translator,
+    Candidate* candidate,
+    ParseError* error) {
+  return ParseCandidate(ICEPROTO_GOOGLE, elem, translator, candidate, error);
+}
+
+bool P2PTransportParser::WriteGingleCandidate(
+    const Candidate& candidate,
+    const CandidateTranslator* translator,
+    buzz::XmlElement** out_elem,
+    WriteError* error) {
+  rtc::scoped_ptr<buzz::XmlElement> elem(
+      new buzz::XmlElement(QN_GINGLE_CANDIDATE));                                     
+  bool ret = WriteCandidate(ICEPROTO_GOOGLE, candidate, translator, elem.get(),
+                            error);
+  if (ret) {
+    *out_elem = elem.release();
+  }
+  return ret;
+}
+
+bool P2PTransportParser::VerifyUsernameFormat(TransportProtocol proto,
+                                              const std::string& username,
+                                              ParseError* error) {
+  if (proto == ICEPROTO_GOOGLE || proto == ICEPROTO_HYBRID) {
+    if (username.size() > kMaxGiceUsernameSize)
+      return BadParse("candidate username is too long", error);
+    if (!rtc::Base64::IsBase64Encoded(username))
+      return BadParse("candidate username has non-base64 encoded characters",
+                      error);
+  } else if (proto == ICEPROTO_RFC5245) {
+    if (username.size() > kMaxIceUsernameSize)
+      return BadParse("candidate username is too long", error);
+  }
+  return true;
+}
+
+bool P2PTransportParser::ParseCandidate(TransportProtocol proto,
+                                        const buzz::XmlElement* elem,
+                                        const CandidateTranslator* translator,
+                                        Candidate* candidate,
+                                        ParseError* error) {
+  ASSERT(proto == ICEPROTO_GOOGLE);
+  ASSERT(translator != NULL);
+
+  if (!elem->HasAttr(buzz::QN_NAME) ||
+      !elem->HasAttr(QN_ADDRESS) ||
+      !elem->HasAttr(QN_PORT) ||
+      !elem->HasAttr(QN_USERNAME) ||
+      !elem->HasAttr(QN_PROTOCOL) ||
+      !elem->HasAttr(QN_GENERATION)) {
+    return BadParse("candidate missing required attribute", error);
+  }
+
+  rtc::SocketAddress address;
+  if (!ParseAddress(elem, QN_ADDRESS, QN_PORT, &address, error))
+    return false;
+
+  std::string channel_name = elem->Attr(buzz::QN_NAME);
+  int component = 0;
+  if (!translator ||
+      !translator->GetComponentFromChannelName(channel_name, &component)) {
+    return BadParse("candidate has unknown channel name " + channel_name,
+                    error);
+  }
+
+  float preference = 0.0;
+  if (!GetXmlAttr(elem, QN_PREFERENCE, 0.0f, &preference)) {
+    return BadParse("candidate has unknown preference", error);
+  }
+
+  candidate->set_component(component);
+  candidate->set_address(address);
+  candidate->set_username(elem->Attr(QN_USERNAME));
+  candidate->set_preference(preference);
+  candidate->set_protocol(elem->Attr(QN_PROTOCOL));
+  candidate->set_generation_str(elem->Attr(QN_GENERATION));
+  if (elem->HasAttr(QN_PASSWORD))
+    candidate->set_password(elem->Attr(QN_PASSWORD));
+  if (elem->HasAttr(buzz::QN_TYPE))
+    candidate->set_type(elem->Attr(buzz::QN_TYPE));
+  if (elem->HasAttr(QN_NETWORK))
+    candidate->set_network_name(elem->Attr(QN_NETWORK));
+
+  if (!VerifyUsernameFormat(proto, candidate->username(), error))
+    return false;
+
+  return true;
+}
+
+bool P2PTransportParser::WriteCandidate(TransportProtocol proto,
+                                        const Candidate& candidate,
+                                        const CandidateTranslator* translator,
+                                        buzz::XmlElement* elem,
+                                        WriteError* error) {
+  ASSERT(proto == ICEPROTO_GOOGLE);
+  ASSERT(translator != NULL);
+
+  std::string channel_name;
+  if (!translator ||
+      !translator->GetChannelNameFromComponent(
+          candidate.component(), &channel_name)) {
+    return BadWrite("Cannot write candidate because of unknown component.",
+                    error);
+  }
+
+  elem->SetAttr(buzz::QN_NAME, channel_name);
+  elem->SetAttr(QN_ADDRESS, candidate.address().ipaddr().ToString());
+  elem->SetAttr(QN_PORT, candidate.address().PortAsString());
+  AddXmlAttr(elem, QN_PREFERENCE, candidate.preference());
+  elem->SetAttr(QN_USERNAME, candidate.username());
+  elem->SetAttr(QN_PROTOCOL, candidate.protocol());
+  elem->SetAttr(QN_GENERATION, candidate.generation_str());
+  if (!candidate.password().empty())
+    elem->SetAttr(QN_PASSWORD, candidate.password());
+  elem->SetAttr(buzz::QN_TYPE, candidate.type());
+  if (!candidate.network_name().empty())
+    elem->SetAttr(QN_NETWORK, candidate.network_name());
+
+  return true;
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/p2ptransport.h b/webrtc/p2p/base/p2ptransport.h
new file mode 100644
index 0000000..efc6599
--- /dev/null
+++ b/webrtc/p2p/base/p2ptransport.h
@@ -0,0 +1,86 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_P2PTRANSPORT_H_
+#define WEBRTC_P2P_BASE_P2PTRANSPORT_H_
+
+#include <string>
+#include <vector>
+#include "webrtc/p2p/base/transport.h"
+
+namespace cricket {
+
+class P2PTransport : public Transport {
+ public:
+  P2PTransport(rtc::Thread* signaling_thread,
+               rtc::Thread* worker_thread,
+               const std::string& content_name,
+               PortAllocator* allocator);
+  virtual ~P2PTransport();
+
+ protected:
+  // Creates and destroys P2PTransportChannel.
+  virtual TransportChannelImpl* CreateTransportChannel(int component);
+  virtual void DestroyTransportChannel(TransportChannelImpl* channel);
+
+  friend class P2PTransportChannel;
+
+  DISALLOW_EVIL_CONSTRUCTORS(P2PTransport);
+};
+
+class P2PTransportParser : public TransportParser {
+ public:
+  P2PTransportParser() {}
+  // Translator may be null, in which case ParseCandidates should
+  // return false if there are candidates to parse.  We can't not call
+  // ParseCandidates because there's no way to know ahead of time if
+  // there are candidates or not.
+
+  // Jingle-specific functions; can be used with either ICE, GICE, or HYBRID.
+  virtual bool ParseTransportDescription(const buzz::XmlElement* elem,
+                                         const CandidateTranslator* translator,
+                                         TransportDescription* desc,
+                                         ParseError* error);
+  virtual bool WriteTransportDescription(const TransportDescription& desc,
+                                         const CandidateTranslator* translator,
+                                         buzz::XmlElement** elem,
+                                         WriteError* error);
+
+  // Legacy Gingle functions; only can be used with GICE.
+  virtual bool ParseGingleCandidate(const buzz::XmlElement* elem,
+                                    const CandidateTranslator* translator,
+                                    Candidate* candidate,
+                                    ParseError* error);
+  virtual bool WriteGingleCandidate(const Candidate& candidate,
+                                    const CandidateTranslator* translator,
+                                    buzz::XmlElement** elem,
+                                    WriteError* error);
+
+ private:
+  bool ParseCandidate(TransportProtocol proto,
+                      const buzz::XmlElement* elem,
+                      const CandidateTranslator* translator,
+                      Candidate* candidate,
+                      ParseError* error);
+  bool WriteCandidate(TransportProtocol proto,
+                      const Candidate& candidate,
+                      const CandidateTranslator* translator,
+                      buzz::XmlElement* elem,
+                      WriteError* error);
+  bool VerifyUsernameFormat(TransportProtocol proto,
+                            const std::string& username,
+                            ParseError* error);
+
+  DISALLOW_EVIL_CONSTRUCTORS(P2PTransportParser);
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_P2PTRANSPORT_H_
diff --git a/webrtc/p2p/base/p2ptransportchannel.cc b/webrtc/p2p/base/p2ptransportchannel.cc
new file mode 100644
index 0000000..84a2420
--- /dev/null
+++ b/webrtc/p2p/base/p2ptransportchannel.cc
@@ -0,0 +1,1274 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/p2ptransportchannel.h"
+
+#include <set>
+#include "webrtc/p2p/base/common.h"
+#include "webrtc/p2p/base/relayport.h"  // For RELAY_PORT_TYPE.
+#include "webrtc/p2p/base/stunport.h"  // For STUN_PORT_TYPE.
+#include "webrtc/base/common.h"
+#include "webrtc/base/crc32.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/stringencode.h"
+
+namespace {
+
+// messages for queuing up work for ourselves
+enum {
+  MSG_SORT = 1,
+  MSG_PING,
+};
+
+// When the socket is unwritable, we will use 10 Kbps (ignoring IP+UDP headers)
+// for pinging.  When the socket is writable, we will use only 1 Kbps because
+// we don't want to degrade the quality on a modem.  These numbers should work
+// well on a 28.8K modem, which is the slowest connection on which the voice
+// quality is reasonable at all.
+static const uint32 PING_PACKET_SIZE = 60 * 8;
+static const uint32 WRITABLE_DELAY = 1000 * PING_PACKET_SIZE / 1000;  // 480ms
+static const uint32 UNWRITABLE_DELAY = 1000 * PING_PACKET_SIZE / 10000;  // 50ms
+
+// If there is a current writable connection, then we will also try hard to
+// make sure it is pinged at this rate.
+static const uint32 MAX_CURRENT_WRITABLE_DELAY = 900;  // 2*WRITABLE_DELAY - bit
+
+// The minimum improvement in RTT that justifies a switch.
+static const double kMinImprovement = 10;
+
+cricket::PortInterface::CandidateOrigin GetOrigin(cricket::PortInterface* port,
+                                         cricket::PortInterface* origin_port) {
+  if (!origin_port)
+    return cricket::PortInterface::ORIGIN_MESSAGE;
+  else if (port == origin_port)
+    return cricket::PortInterface::ORIGIN_THIS_PORT;
+  else
+    return cricket::PortInterface::ORIGIN_OTHER_PORT;
+}
+
+// Compares two connections based only on static information about them.
+int CompareConnectionCandidates(cricket::Connection* a,
+                                cricket::Connection* b) {
+  // Compare connection priority. Lower values get sorted last.
+  if (a->priority() > b->priority())
+    return 1;
+  if (a->priority() < b->priority())
+    return -1;
+
+  // If we're still tied at this point, prefer a younger generation.
+  return (a->remote_candidate().generation() + a->port()->generation()) -
+         (b->remote_candidate().generation() + b->port()->generation());
+}
+
+// Compare two connections based on their writability and static preferences.
+int CompareConnections(cricket::Connection *a, cricket::Connection *b) {
+  // Sort based on write-state.  Better states have lower values.
+  if (a->write_state() < b->write_state())
+    return 1;
+  if (a->write_state() > b->write_state())
+    return -1;
+
+  // Compare the candidate information.
+  return CompareConnectionCandidates(a, b);
+}
+
+// Wraps the comparison connection into a less than operator that puts higher
+// priority writable connections first.
+class ConnectionCompare {
+ public:
+  bool operator()(const cricket::Connection *ca,
+                  const cricket::Connection *cb) {
+    cricket::Connection* a = const_cast<cricket::Connection*>(ca);
+    cricket::Connection* b = const_cast<cricket::Connection*>(cb);
+
+    ASSERT(a->port()->IceProtocol() == b->port()->IceProtocol());
+
+    // Compare first on writability and static preferences.
+    int cmp = CompareConnections(a, b);
+    if (cmp > 0)
+      return true;
+    if (cmp < 0)
+      return false;
+
+    // Otherwise, sort based on latency estimate.
+    return a->rtt() < b->rtt();
+
+    // Should we bother checking for the last connection that last received
+    // data? It would help rendezvous on the connection that is also receiving
+    // packets.
+    //
+    // TODO: Yes we should definitely do this.  The TCP protocol gains
+    // efficiency by being used bidirectionally, as opposed to two separate
+    // unidirectional streams.  This test should probably occur before
+    // comparison of local prefs (assuming combined prefs are the same).  We
+    // need to be careful though, not to bounce back and forth with both sides
+    // trying to rendevous with the other.
+  }
+};
+
+// Determines whether we should switch between two connections, based first on
+// static preferences and then (if those are equal) on latency estimates.
+bool ShouldSwitch(cricket::Connection* a_conn, cricket::Connection* b_conn) {
+  if (a_conn == b_conn)
+    return false;
+
+  if (!a_conn || !b_conn)  // don't think the latter should happen
+    return true;
+
+  int prefs_cmp = CompareConnections(a_conn, b_conn);
+  if (prefs_cmp < 0)
+    return true;
+  if (prefs_cmp > 0)
+    return false;
+
+  return b_conn->rtt() <= a_conn->rtt() + kMinImprovement;
+}
+
+}  // unnamed namespace
+
+namespace cricket {
+
+P2PTransportChannel::P2PTransportChannel(const std::string& content_name,
+                                         int component,
+                                         P2PTransport* transport,
+                                         PortAllocator *allocator) :
+    TransportChannelImpl(content_name, component),
+    transport_(transport),
+    allocator_(allocator),
+    worker_thread_(rtc::Thread::Current()),
+    incoming_only_(false),
+    waiting_for_signaling_(false),
+    error_(0),
+    best_connection_(NULL),
+    pending_best_connection_(NULL),
+    sort_dirty_(false),
+    was_writable_(false),
+    protocol_type_(ICEPROTO_HYBRID),
+    remote_ice_mode_(ICEMODE_FULL),
+    ice_role_(ICEROLE_UNKNOWN),
+    tiebreaker_(0),
+    remote_candidate_generation_(0) {
+}
+
+P2PTransportChannel::~P2PTransportChannel() {
+  ASSERT(worker_thread_ == rtc::Thread::Current());
+
+  for (uint32 i = 0; i < allocator_sessions_.size(); ++i)
+    delete allocator_sessions_[i];
+}
+
+// Add the allocator session to our list so that we know which sessions
+// are still active.
+void P2PTransportChannel::AddAllocatorSession(PortAllocatorSession* session) {
+  session->set_generation(static_cast<uint32>(allocator_sessions_.size()));
+  allocator_sessions_.push_back(session);
+
+  // We now only want to apply new candidates that we receive to the ports
+  // created by this new session because these are replacing those of the
+  // previous sessions.
+  ports_.clear();
+
+  session->SignalPortReady.connect(this, &P2PTransportChannel::OnPortReady);
+  session->SignalCandidatesReady.connect(
+      this, &P2PTransportChannel::OnCandidatesReady);
+  session->SignalCandidatesAllocationDone.connect(
+      this, &P2PTransportChannel::OnCandidatesAllocationDone);
+  session->StartGettingPorts();
+}
+
+void P2PTransportChannel::AddConnection(Connection* connection) {
+  connections_.push_back(connection);
+  connection->set_remote_ice_mode(remote_ice_mode_);
+  connection->SignalReadPacket.connect(
+      this, &P2PTransportChannel::OnReadPacket);
+  connection->SignalReadyToSend.connect(
+      this, &P2PTransportChannel::OnReadyToSend);
+  connection->SignalStateChange.connect(
+      this, &P2PTransportChannel::OnConnectionStateChange);
+  connection->SignalDestroyed.connect(
+      this, &P2PTransportChannel::OnConnectionDestroyed);
+  connection->SignalUseCandidate.connect(
+      this, &P2PTransportChannel::OnUseCandidate);
+}
+
+void P2PTransportChannel::SetIceRole(IceRole ice_role) {
+  ASSERT(worker_thread_ == rtc::Thread::Current());
+  if (ice_role_ != ice_role) {
+    ice_role_ = ice_role;
+    for (std::vector<PortInterface *>::iterator it = ports_.begin();
+         it != ports_.end(); ++it) {
+      (*it)->SetIceRole(ice_role);
+    }
+  }
+}
+
+void P2PTransportChannel::SetIceTiebreaker(uint64 tiebreaker) {
+  ASSERT(worker_thread_ == rtc::Thread::Current());
+  if (!ports_.empty()) {
+    LOG(LS_ERROR)
+        << "Attempt to change tiebreaker after Port has been allocated.";
+    return;
+  }
+
+  tiebreaker_ = tiebreaker;
+}
+
+bool P2PTransportChannel::GetIceProtocolType(IceProtocolType* type) const {
+  *type = protocol_type_;
+  return true;
+}
+
+void P2PTransportChannel::SetIceProtocolType(IceProtocolType type) {
+  ASSERT(worker_thread_ == rtc::Thread::Current());
+
+  protocol_type_ = type;
+  for (std::vector<PortInterface *>::iterator it = ports_.begin();
+       it != ports_.end(); ++it) {
+    (*it)->SetIceProtocolType(protocol_type_);
+  }
+}
+
+void P2PTransportChannel::SetIceCredentials(const std::string& ice_ufrag,
+                                            const std::string& ice_pwd) {
+  ASSERT(worker_thread_ == rtc::Thread::Current());
+  bool ice_restart = false;
+  if (!ice_ufrag_.empty() && !ice_pwd_.empty()) {
+    // Restart candidate allocation if there is any change in either
+    // ice ufrag or password.
+    ice_restart =
+        IceCredentialsChanged(ice_ufrag_, ice_pwd_, ice_ufrag, ice_pwd);
+  }
+
+  ice_ufrag_ = ice_ufrag;
+  ice_pwd_ = ice_pwd;
+
+  if (ice_restart) {
+    // Restart candidate gathering.
+    Allocate();
+  }
+}
+
+void P2PTransportChannel::SetRemoteIceCredentials(const std::string& ice_ufrag,
+                                                  const std::string& ice_pwd) {
+  ASSERT(worker_thread_ == rtc::Thread::Current());
+  bool ice_restart = false;
+  if (!remote_ice_ufrag_.empty() && !remote_ice_pwd_.empty()) {
+    ice_restart = (remote_ice_ufrag_ != ice_ufrag) ||
+                  (remote_ice_pwd_!= ice_pwd);
+  }
+
+  remote_ice_ufrag_ = ice_ufrag;
+  remote_ice_pwd_ = ice_pwd;
+
+  if (ice_restart) {
+    // |candidate.generation()| is not signaled in ICEPROTO_RFC5245.
+    // Therefore we need to keep track of the remote ice restart so
+    // newer connections are prioritized over the older.
+    ++remote_candidate_generation_;
+  }
+}
+
+void P2PTransportChannel::SetRemoteIceMode(IceMode mode) {
+  remote_ice_mode_ = mode;
+}
+
+// Go into the state of processing candidates, and running in general
+void P2PTransportChannel::Connect() {
+  ASSERT(worker_thread_ == rtc::Thread::Current());
+  if (ice_ufrag_.empty() || ice_pwd_.empty()) {
+    ASSERT(false);
+    LOG(LS_ERROR) << "P2PTransportChannel::Connect: The ice_ufrag_ and the "
+                  << "ice_pwd_ are not set.";
+    return;
+  }
+
+  // Kick off an allocator session
+  Allocate();
+
+  // Start pinging as the ports come in.
+  thread()->Post(this, MSG_PING);
+}
+
+// Reset the socket, clear up any previous allocations and start over
+void P2PTransportChannel::Reset() {
+  ASSERT(worker_thread_ == rtc::Thread::Current());
+
+  // Get rid of all the old allocators.  This should clean up everything.
+  for (uint32 i = 0; i < allocator_sessions_.size(); ++i)
+    delete allocator_sessions_[i];
+
+  allocator_sessions_.clear();
+  ports_.clear();
+  connections_.clear();
+  best_connection_ = NULL;
+
+  // Forget about all of the candidates we got before.
+  remote_candidates_.clear();
+
+  // Revert to the initial state.
+  set_readable(false);
+  set_writable(false);
+
+  // Reinitialize the rest of our state.
+  waiting_for_signaling_ = false;
+  sort_dirty_ = false;
+
+  // If we allocated before, start a new one now.
+  if (transport_->connect_requested())
+    Allocate();
+
+  // Start pinging as the ports come in.
+  thread()->Clear(this);
+  thread()->Post(this, MSG_PING);
+}
+
+// A new port is available, attempt to make connections for it
+void P2PTransportChannel::OnPortReady(PortAllocatorSession *session,
+                                      PortInterface* port) {
+  ASSERT(worker_thread_ == rtc::Thread::Current());
+
+  // Set in-effect options on the new port
+  for (OptionMap::const_iterator it = options_.begin();
+       it != options_.end();
+       ++it) {
+    int val = port->SetOption(it->first, it->second);
+    if (val < 0) {
+      LOG_J(LS_WARNING, port) << "SetOption(" << it->first
+                              << ", " << it->second
+                              << ") failed: " << port->GetError();
+    }
+  }
+
+  // Remember the ports and candidates, and signal that candidates are ready.
+  // The session will handle this, and send an initiate/accept/modify message
+  // if one is pending.
+
+  port->SetIceProtocolType(protocol_type_);
+  port->SetIceRole(ice_role_);
+  port->SetIceTiebreaker(tiebreaker_);
+  ports_.push_back(port);
+  port->SignalUnknownAddress.connect(
+      this, &P2PTransportChannel::OnUnknownAddress);
+  port->SignalDestroyed.connect(this, &P2PTransportChannel::OnPortDestroyed);
+  port->SignalRoleConflict.connect(
+      this, &P2PTransportChannel::OnRoleConflict);
+
+  // Attempt to create a connection from this new port to all of the remote
+  // candidates that we were given so far.
+
+  std::vector<RemoteCandidate>::iterator iter;
+  for (iter = remote_candidates_.begin(); iter != remote_candidates_.end();
+       ++iter) {
+    CreateConnection(port, *iter, iter->origin_port(), false);
+  }
+
+  SortConnections();
+}
+
+// A new candidate is available, let listeners know
+void P2PTransportChannel::OnCandidatesReady(
+    PortAllocatorSession *session, const std::vector<Candidate>& candidates) {
+  ASSERT(worker_thread_ == rtc::Thread::Current());
+  for (size_t i = 0; i < candidates.size(); ++i) {
+    SignalCandidateReady(this, candidates[i]);
+  }
+}
+
+void P2PTransportChannel::OnCandidatesAllocationDone(
+    PortAllocatorSession* session) {
+  ASSERT(worker_thread_ == rtc::Thread::Current());
+  SignalCandidatesAllocationDone(this);
+}
+
+// Handle stun packets
+void P2PTransportChannel::OnUnknownAddress(
+    PortInterface* port,
+    const rtc::SocketAddress& address, ProtocolType proto,
+    IceMessage* stun_msg, const std::string &remote_username,
+    bool port_muxed) {
+  ASSERT(worker_thread_ == rtc::Thread::Current());
+
+  // Port has received a valid stun packet from an address that no Connection
+  // is currently available for. See if we already have a candidate with the
+  // address. If it isn't we need to create new candidate for it.
+
+  // Determine if the remote candidates use shared ufrag.
+  bool ufrag_per_port = false;
+  std::vector<RemoteCandidate>::iterator it;
+  if (remote_candidates_.size() > 0) {
+    it = remote_candidates_.begin();
+    std::string username = it->username();
+    for (; it != remote_candidates_.end(); ++it) {
+      if (it->username() != username) {
+        ufrag_per_port = true;
+        break;
+      }
+    }
+  }
+
+  const Candidate* candidate = NULL;
+  bool known_username = false;
+  std::string remote_password;
+  for (it = remote_candidates_.begin(); it != remote_candidates_.end(); ++it) {
+    if (it->username() == remote_username) {
+      remote_password = it->password();
+      known_username = true;
+      if (ufrag_per_port ||
+          (it->address() == address &&
+           it->protocol() == ProtoToString(proto))) {
+        candidate = &(*it);
+        break;
+      }
+      // We don't want to break here because we may find a match of the address
+      // later.
+    }
+  }
+
+  if (!known_username) {
+    if (port_muxed) {
+      // When Ports are muxed, SignalUnknownAddress is delivered to all
+      // P2PTransportChannel belong to a session. Return from here will
+      // save us from sending stun binding error message from incorrect channel.
+      return;
+    }
+    // Don't know about this username, the request is bogus
+    // This sometimes happens if a binding response comes in before the ACCEPT
+    // message.  It is totally valid; the retry state machine will try again.
+    port->SendBindingErrorResponse(stun_msg, address,
+        STUN_ERROR_STALE_CREDENTIALS, STUN_ERROR_REASON_STALE_CREDENTIALS);
+    return;
+  }
+
+  Candidate new_remote_candidate;
+  if (candidate != NULL) {
+    new_remote_candidate = *candidate;
+    if (ufrag_per_port) {
+      new_remote_candidate.set_address(address);
+    }
+  } else {
+    // Create a new candidate with this address.
+    std::string type;
+    if (port->IceProtocol() == ICEPROTO_RFC5245) {
+      type = PRFLX_PORT_TYPE;
+    } else {
+      // G-ICE doesn't support prflx candidate.
+      // We set candidate type to STUN_PORT_TYPE if the binding request comes
+      // from a relay port or the shared socket is used. Otherwise we use the
+      // port's type as the candidate type.
+      if (port->Type() == RELAY_PORT_TYPE || port->SharedSocket()) {
+        type = STUN_PORT_TYPE;
+      } else {
+        type = port->Type();
+      }
+    }
+
+    std::string id = rtc::CreateRandomString(8);
+    new_remote_candidate = Candidate(
+        id, component(), ProtoToString(proto), address,
+        0, remote_username, remote_password, type,
+        port->Network()->name(), 0U,
+        rtc::ToString<uint32>(rtc::ComputeCrc32(id)));
+    new_remote_candidate.set_priority(
+        new_remote_candidate.GetPriority(ICE_TYPE_PREFERENCE_SRFLX,
+                                         port->Network()->preference(), 0));
+  }
+
+  if (port->IceProtocol() == ICEPROTO_RFC5245) {
+    // RFC 5245
+    // If the source transport address of the request does not match any
+    // existing remote candidates, it represents a new peer reflexive remote
+    // candidate.
+
+    // The priority of the candidate is set to the PRIORITY attribute
+    // from the request.
+    const StunUInt32Attribute* priority_attr =
+        stun_msg->GetUInt32(STUN_ATTR_PRIORITY);
+    if (!priority_attr) {
+      LOG(LS_WARNING) << "P2PTransportChannel::OnUnknownAddress - "
+                      << "No STUN_ATTR_PRIORITY found in the "
+                      << "stun request message";
+      port->SendBindingErrorResponse(stun_msg, address,
+                                     STUN_ERROR_BAD_REQUEST,
+                                     STUN_ERROR_REASON_BAD_REQUEST);
+      return;
+    }
+    new_remote_candidate.set_priority(priority_attr->value());
+
+    // RFC5245, the agent constructs a pair whose local candidate is equal to
+    // the transport address on which the STUN request was received, and a
+    // remote candidate equal to the source transport address where the
+    // request came from.
+
+    // There shouldn't be an existing connection with this remote address.
+    // When ports are muxed, this channel might get multiple unknown address
+    // signals. In that case if the connection is already exists, we should
+    // simply ignore the signal othewise send server error.
+    if (port->GetConnection(new_remote_candidate.address())) {
+      if (port_muxed) {
+        LOG(LS_INFO) << "Connection already exists for peer reflexive "
+                     << "candidate: " << new_remote_candidate.ToString();
+        return;
+      } else {
+        ASSERT(false);
+        port->SendBindingErrorResponse(stun_msg, address,
+                                       STUN_ERROR_SERVER_ERROR,
+                                       STUN_ERROR_REASON_SERVER_ERROR);
+        return;
+      }
+    }
+
+    Connection* connection = port->CreateConnection(
+        new_remote_candidate, cricket::PortInterface::ORIGIN_THIS_PORT);
+    if (!connection) {
+      ASSERT(false);
+      port->SendBindingErrorResponse(stun_msg, address,
+                                     STUN_ERROR_SERVER_ERROR,
+                                     STUN_ERROR_REASON_SERVER_ERROR);
+      return;
+    }
+
+    AddConnection(connection);
+    connection->ReceivedPing();
+
+    // Send the pinger a successful stun response.
+    port->SendBindingResponse(stun_msg, address);
+
+    // Update the list of connections since we just added another.  We do this
+    // after sending the response since it could (in principle) delete the
+    // connection in question.
+    SortConnections();
+  } else {
+    // Check for connectivity to this address. Create connections
+    // to this address across all local ports. First, add this as a new remote
+    // address
+    if (!CreateConnections(new_remote_candidate, port, true)) {
+      // Hopefully this won't occur, because changing a destination address
+      // shouldn't cause a new connection to fail
+      ASSERT(false);
+      port->SendBindingErrorResponse(stun_msg, address, STUN_ERROR_SERVER_ERROR,
+          STUN_ERROR_REASON_SERVER_ERROR);
+      return;
+    }
+
+    // Send the pinger a successful stun response.
+    port->SendBindingResponse(stun_msg, address);
+
+    // Update the list of connections since we just added another.  We do this
+    // after sending the response since it could (in principle) delete the
+    // connection in question.
+    SortConnections();
+  }
+}
+
+void P2PTransportChannel::OnRoleConflict(PortInterface* port) {
+  SignalRoleConflict(this);  // STUN ping will be sent when SetRole is called
+                             // from Transport.
+}
+
+// When the signalling channel is ready, we can really kick off the allocator
+void P2PTransportChannel::OnSignalingReady() {
+  ASSERT(worker_thread_ == rtc::Thread::Current());
+  if (waiting_for_signaling_) {
+    waiting_for_signaling_ = false;
+    AddAllocatorSession(allocator_->CreateSession(
+        SessionId(), content_name(), component(), ice_ufrag_, ice_pwd_));
+  }
+}
+
+void P2PTransportChannel::OnUseCandidate(Connection* conn) {
+  ASSERT(worker_thread_ == rtc::Thread::Current());
+  ASSERT(ice_role_ == ICEROLE_CONTROLLED);
+  ASSERT(protocol_type_ == ICEPROTO_RFC5245);
+  if (conn->write_state() == Connection::STATE_WRITABLE) {
+    if (best_connection_ != conn) {
+      pending_best_connection_ = NULL;
+      SwitchBestConnectionTo(conn);
+      // Now we have selected the best connection, time to prune other existing
+      // connections and update the read/write state of the channel.
+      RequestSort();
+    }
+  } else {
+    pending_best_connection_ = conn;
+  }
+}
+
+void P2PTransportChannel::OnCandidate(const Candidate& candidate) {
+  ASSERT(worker_thread_ == rtc::Thread::Current());
+
+  // Create connections to this remote candidate.
+  CreateConnections(candidate, NULL, false);
+
+  // Resort the connections list, which may have new elements.
+  SortConnections();
+}
+
+// Creates connections from all of the ports that we care about to the given
+// remote candidate.  The return value is true if we created a connection from
+// the origin port.
+bool P2PTransportChannel::CreateConnections(const Candidate& remote_candidate,
+                                            PortInterface* origin_port,
+                                            bool readable) {
+  ASSERT(worker_thread_ == rtc::Thread::Current());
+
+  Candidate new_remote_candidate(remote_candidate);
+  new_remote_candidate.set_generation(
+      GetRemoteCandidateGeneration(remote_candidate));
+  // ICE candidates don't need to have username and password set, but
+  // the code below this (specifically, ConnectionRequest::Prepare in
+  // port.cc) uses the remote candidates's username.  So, we set it
+  // here.
+  if (remote_candidate.username().empty()) {
+    new_remote_candidate.set_username(remote_ice_ufrag_);
+  }
+  if (remote_candidate.password().empty()) {
+    new_remote_candidate.set_password(remote_ice_pwd_);
+  }
+
+  // If we've already seen the new remote candidate (in the current candidate
+  // generation), then we shouldn't try creating connections for it.
+  // We either already have a connection for it, or we previously created one
+  // and then later pruned it. If we don't return, the channel will again
+  // re-create any connections that were previously pruned, which will then
+  // immediately be re-pruned, churning the network for no purpose.
+  // This only applies to candidates received over signaling (i.e. origin_port
+  // is NULL).
+  if (!origin_port && IsDuplicateRemoteCandidate(new_remote_candidate)) {
+    // return true to indicate success, without creating any new connections.
+    return true;
+  }
+
+  // Add a new connection for this candidate to every port that allows such a
+  // connection (i.e., if they have compatible protocols) and that does not
+  // already have a connection to an equivalent candidate.  We must be careful
+  // to make sure that the origin port is included, even if it was pruned,
+  // since that may be the only port that can create this connection.
+  bool created = false;
+  std::vector<PortInterface *>::reverse_iterator it;
+  for (it = ports_.rbegin(); it != ports_.rend(); ++it) {
+    if (CreateConnection(*it, new_remote_candidate, origin_port, readable)) {
+      if (*it == origin_port)
+        created = true;
+    }
+  }
+
+  if ((origin_port != NULL) &&
+      std::find(ports_.begin(), ports_.end(), origin_port) == ports_.end()) {
+    if (CreateConnection(
+        origin_port, new_remote_candidate, origin_port, readable))
+      created = true;
+  }
+
+  // Remember this remote candidate so that we can add it to future ports.
+  RememberRemoteCandidate(new_remote_candidate, origin_port);
+
+  return created;
+}
+
+// Setup a connection object for the local and remote candidate combination.
+// And then listen to connection object for changes.
+bool P2PTransportChannel::CreateConnection(PortInterface* port,
+                                           const Candidate& remote_candidate,
+                                           PortInterface* origin_port,
+                                           bool readable) {
+  // Look for an existing connection with this remote address.  If one is not
+  // found, then we can create a new connection for this address.
+  Connection* connection = port->GetConnection(remote_candidate.address());
+  if (connection != NULL) {
+    // It is not legal to try to change any of the parameters of an existing
+    // connection; however, the other side can send a duplicate candidate.
+    if (!remote_candidate.IsEquivalent(connection->remote_candidate())) {
+      LOG(INFO) << "Attempt to change a remote candidate."
+                << " Existing remote candidate: "
+                << connection->remote_candidate().ToString()
+                << "New remote candidate: "
+                << remote_candidate.ToString();
+      return false;
+    }
+  } else {
+    PortInterface::CandidateOrigin origin = GetOrigin(port, origin_port);
+
+    // Don't create connection if this is a candidate we received in a
+    // message and we are not allowed to make outgoing connections.
+    if (origin == cricket::PortInterface::ORIGIN_MESSAGE && incoming_only_)
+      return false;
+
+    connection = port->CreateConnection(remote_candidate, origin);
+    if (!connection)
+      return false;
+
+    AddConnection(connection);
+
+    LOG_J(LS_INFO, this) << "Created connection with origin=" << origin << ", ("
+                         << connections_.size() << " total)";
+  }
+
+  // If we are readable, it is because we are creating this in response to a
+  // ping from the other side.  This will cause the state to become readable.
+  if (readable)
+    connection->ReceivedPing();
+
+  return true;
+}
+
+bool P2PTransportChannel::FindConnection(
+    cricket::Connection* connection) const {
+  std::vector<Connection*>::const_iterator citer =
+      std::find(connections_.begin(), connections_.end(), connection);
+  return citer != connections_.end();
+}
+
+uint32 P2PTransportChannel::GetRemoteCandidateGeneration(
+    const Candidate& candidate) {
+  if (protocol_type_ == ICEPROTO_GOOGLE) {
+    // The Candidate.generation() can be trusted. Nothing needs to be done.
+    return candidate.generation();
+  }
+  // |candidate.generation()| is not signaled in ICEPROTO_RFC5245.
+  // Therefore we need to keep track of the remote ice restart so
+  // newer connections are prioritized over the older.
+  ASSERT(candidate.generation() == 0 ||
+         candidate.generation() == remote_candidate_generation_);
+  return remote_candidate_generation_;
+}
+
+// Check if remote candidate is already cached.
+bool P2PTransportChannel::IsDuplicateRemoteCandidate(
+    const Candidate& candidate) {
+  for (uint32 i = 0; i < remote_candidates_.size(); ++i) {
+    if (remote_candidates_[i].IsEquivalent(candidate)) {
+      return true;
+    }
+  }
+  return false;
+}
+
+// Maintain our remote candidate list, adding this new remote one.
+void P2PTransportChannel::RememberRemoteCandidate(
+    const Candidate& remote_candidate, PortInterface* origin_port) {
+  // Remove any candidates whose generation is older than this one.  The
+  // presence of a new generation indicates that the old ones are not useful.
+  uint32 i = 0;
+  while (i < remote_candidates_.size()) {
+    if (remote_candidates_[i].generation() < remote_candidate.generation()) {
+      LOG(INFO) << "Pruning candidate from old generation: "
+                << remote_candidates_[i].address().ToSensitiveString();
+      remote_candidates_.erase(remote_candidates_.begin() + i);
+    } else {
+      i += 1;
+    }
+  }
+
+  // Make sure this candidate is not a duplicate.
+  if (IsDuplicateRemoteCandidate(remote_candidate)) {
+    LOG(INFO) << "Duplicate candidate: " << remote_candidate.ToString();
+    return;
+  }
+
+  // Try this candidate for all future ports.
+  remote_candidates_.push_back(RemoteCandidate(remote_candidate, origin_port));
+}
+
+// Set options on ourselves is simply setting options on all of our available
+// port objects.
+int P2PTransportChannel::SetOption(rtc::Socket::Option opt, int value) {
+  OptionMap::iterator it = options_.find(opt);
+  if (it == options_.end()) {
+    options_.insert(std::make_pair(opt, value));
+  } else if (it->second == value) {
+    return 0;
+  } else {
+    it->second = value;
+  }
+
+  for (uint32 i = 0; i < ports_.size(); ++i) {
+    int val = ports_[i]->SetOption(opt, value);
+    if (val < 0) {
+      // Because this also occurs deferred, probably no point in reporting an
+      // error
+      LOG(WARNING) << "SetOption(" << opt << ", " << value << ") failed: "
+                   << ports_[i]->GetError();
+    }
+  }
+  return 0;
+}
+
+// Send data to the other side, using our best connection.
+int P2PTransportChannel::SendPacket(const char *data, size_t len,
+                                    const rtc::PacketOptions& options,
+                                    int flags) {
+  ASSERT(worker_thread_ == rtc::Thread::Current());
+  if (flags != 0) {
+    error_ = EINVAL;
+    return -1;
+  }
+  if (best_connection_ == NULL) {
+    error_ = EWOULDBLOCK;
+    return -1;
+  }
+
+  int sent = best_connection_->Send(data, len, options);
+  if (sent <= 0) {
+    ASSERT(sent < 0);
+    error_ = best_connection_->GetError();
+  }
+  return sent;
+}
+
+bool P2PTransportChannel::GetStats(ConnectionInfos *infos) {
+  ASSERT(worker_thread_ == rtc::Thread::Current());
+  // Gather connection infos.
+  infos->clear();
+
+  std::vector<Connection *>::const_iterator it;
+  for (it = connections_.begin(); it != connections_.end(); ++it) {
+    Connection *connection = *it;
+    ConnectionInfo info;
+    info.best_connection = (best_connection_ == connection);
+    info.readable =
+        (connection->read_state() == Connection::STATE_READABLE);
+    info.writable =
+        (connection->write_state() == Connection::STATE_WRITABLE);
+    info.timeout =
+        (connection->write_state() == Connection::STATE_WRITE_TIMEOUT);
+    info.new_connection = !connection->reported();
+    connection->set_reported(true);
+    info.rtt = connection->rtt();
+    info.sent_total_bytes = connection->sent_total_bytes();
+    info.sent_bytes_second = connection->sent_bytes_second();
+    info.recv_total_bytes = connection->recv_total_bytes();
+    info.recv_bytes_second = connection->recv_bytes_second();
+    info.local_candidate = connection->local_candidate();
+    info.remote_candidate = connection->remote_candidate();
+    info.key = connection;
+    infos->push_back(info);
+  }
+
+  return true;
+}
+
+rtc::DiffServCodePoint P2PTransportChannel::DefaultDscpValue() const {
+  OptionMap::const_iterator it = options_.find(rtc::Socket::OPT_DSCP);
+  if (it == options_.end()) {
+    return rtc::DSCP_NO_CHANGE;
+  }
+  return static_cast<rtc::DiffServCodePoint> (it->second);
+}
+
+// Begin allocate (or immediately re-allocate, if MSG_ALLOCATE pending)
+void P2PTransportChannel::Allocate() {
+  // Time for a new allocator, lets make sure we have a signalling channel
+  // to communicate candidates through first.
+  waiting_for_signaling_ = true;
+  SignalRequestSignaling(this);
+}
+
+// Monitor connection states.
+void P2PTransportChannel::UpdateConnectionStates() {
+  uint32 now = rtc::Time();
+
+  // We need to copy the list of connections since some may delete themselves
+  // when we call UpdateState.
+  for (uint32 i = 0; i < connections_.size(); ++i)
+    connections_[i]->UpdateState(now);
+}
+
+// Prepare for best candidate sorting.
+void P2PTransportChannel::RequestSort() {
+  if (!sort_dirty_) {
+    worker_thread_->Post(this, MSG_SORT);
+    sort_dirty_ = true;
+  }
+}
+
+// Sort the available connections to find the best one.  We also monitor
+// the number of available connections and the current state.
+void P2PTransportChannel::SortConnections() {
+  ASSERT(worker_thread_ == rtc::Thread::Current());
+
+  // Make sure the connection states are up-to-date since this affects how they
+  // will be sorted.
+  UpdateConnectionStates();
+
+  if (protocol_type_ == ICEPROTO_HYBRID) {
+    // If we are in hybrid mode, we are not sending any ping requests, so there
+    // is no point in sorting the connections. In hybrid state, ports can have
+    // different protocol than hybrid and protocol may differ from one another.
+    // Instead just update the state of this channel
+    UpdateChannelState();
+    return;
+  }
+
+  // Any changes after this point will require a re-sort.
+  sort_dirty_ = false;
+
+  // Get a list of the networks that we are using.
+  std::set<rtc::Network*> networks;
+  for (uint32 i = 0; i < connections_.size(); ++i)
+    networks.insert(connections_[i]->port()->Network());
+
+  // Find the best alternative connection by sorting.  It is important to note
+  // that amongst equal preference, writable connections, this will choose the
+  // one whose estimated latency is lowest.  So it is the only one that we
+  // need to consider switching to.
+
+  ConnectionCompare cmp;
+  std::stable_sort(connections_.begin(), connections_.end(), cmp);
+  LOG(LS_VERBOSE) << "Sorting available connections:";
+  for (uint32 i = 0; i < connections_.size(); ++i) {
+    LOG(LS_VERBOSE) << connections_[i]->ToString();
+  }
+
+  Connection* top_connection = NULL;
+  if (connections_.size() > 0)
+    top_connection = connections_[0];
+
+  // We don't want to pick the best connections if channel is using RFC5245
+  // and it's mode is CONTROLLED, as connections will be selected by the
+  // CONTROLLING agent.
+
+  // If necessary, switch to the new choice.
+  if (protocol_type_ != ICEPROTO_RFC5245 || ice_role_ == ICEROLE_CONTROLLING) {
+    if (ShouldSwitch(best_connection_, top_connection))
+      SwitchBestConnectionTo(top_connection);
+  }
+
+  // We can prune any connection for which there is a writable connection on
+  // the same network with better or equal priority.  We leave those with
+  // better priority just in case they become writable later (at which point,
+  // we would prune out the current best connection).  We leave connections on
+  // other networks because they may not be using the same resources and they
+  // may represent very distinct paths over which we can switch.
+  std::set<rtc::Network*>::iterator network;
+  for (network = networks.begin(); network != networks.end(); ++network) {
+    Connection* primier = GetBestConnectionOnNetwork(*network);
+    if (!primier || (primier->write_state() != Connection::STATE_WRITABLE))
+      continue;
+
+    for (uint32 i = 0; i < connections_.size(); ++i) {
+      if ((connections_[i] != primier) &&
+          (connections_[i]->port()->Network() == *network) &&
+          (CompareConnectionCandidates(primier, connections_[i]) >= 0)) {
+        connections_[i]->Prune();
+      }
+    }
+  }
+
+  // Check if all connections are timedout.
+  bool all_connections_timedout = true;
+  for (uint32 i = 0; i < connections_.size(); ++i) {
+    if (connections_[i]->write_state() != Connection::STATE_WRITE_TIMEOUT) {
+      all_connections_timedout = false;
+      break;
+    }
+  }
+
+  // Now update the writable state of the channel with the information we have
+  // so far.
+  if (best_connection_ && best_connection_->writable()) {
+    HandleWritable();
+  } else if (all_connections_timedout) {
+    HandleAllTimedOut();
+  } else {
+    HandleNotWritable();
+  }
+
+  // Update the state of this channel.  This method is called whenever the
+  // state of any connection changes, so this is a good place to do this.
+  UpdateChannelState();
+}
+
+
+// Track the best connection, and let listeners know
+void P2PTransportChannel::SwitchBestConnectionTo(Connection* conn) {
+  // Note: if conn is NULL, the previous best_connection_ has been destroyed,
+  // so don't use it.
+  Connection* old_best_connection = best_connection_;
+  best_connection_ = conn;
+  if (best_connection_) {
+    if (old_best_connection) {
+      LOG_J(LS_INFO, this) << "Previous best connection: "
+                           << old_best_connection->ToString();
+    }
+    LOG_J(LS_INFO, this) << "New best connection: "
+                         << best_connection_->ToString();
+    SignalRouteChange(this, best_connection_->remote_candidate());
+  } else {
+    LOG_J(LS_INFO, this) << "No best connection";
+  }
+}
+
+void P2PTransportChannel::UpdateChannelState() {
+  // The Handle* functions already set the writable state.  We'll just double-
+  // check it here.
+  bool writable = ((best_connection_ != NULL)  &&
+      (best_connection_->write_state() ==
+      Connection::STATE_WRITABLE));
+  ASSERT(writable == this->writable());
+  if (writable != this->writable())
+    LOG(LS_ERROR) << "UpdateChannelState: writable state mismatch";
+
+  bool readable = false;
+  for (uint32 i = 0; i < connections_.size(); ++i) {
+    if (connections_[i]->read_state() == Connection::STATE_READABLE) {
+      readable = true;
+      break;
+    }
+  }
+  set_readable(readable);
+}
+
+// We checked the status of our connections and we had at least one that
+// was writable, go into the writable state.
+void P2PTransportChannel::HandleWritable() {
+  ASSERT(worker_thread_ == rtc::Thread::Current());
+  if (!writable()) {
+    for (uint32 i = 0; i < allocator_sessions_.size(); ++i) {
+      if (allocator_sessions_[i]->IsGettingPorts()) {
+        allocator_sessions_[i]->StopGettingPorts();
+      }
+    }
+  }
+
+  was_writable_ = true;
+  set_writable(true);
+}
+
+// Notify upper layer about channel not writable state, if it was before.
+void P2PTransportChannel::HandleNotWritable() {
+  ASSERT(worker_thread_ == rtc::Thread::Current());
+  if (was_writable_) {
+    was_writable_ = false;
+    set_writable(false);
+  }
+}
+
+void P2PTransportChannel::HandleAllTimedOut() {
+  // Currently we are treating this as channel not writable.
+  HandleNotWritable();
+}
+
+// If we have a best connection, return it, otherwise return top one in the
+// list (later we will mark it best).
+Connection* P2PTransportChannel::GetBestConnectionOnNetwork(
+    rtc::Network* network) {
+  // If the best connection is on this network, then it wins.
+  if (best_connection_ && (best_connection_->port()->Network() == network))
+    return best_connection_;
+
+  // Otherwise, we return the top-most in sorted order.
+  for (uint32 i = 0; i < connections_.size(); ++i) {
+    if (connections_[i]->port()->Network() == network)
+      return connections_[i];
+  }
+
+  return NULL;
+}
+
+// Handle any queued up requests
+void P2PTransportChannel::OnMessage(rtc::Message *pmsg) {
+  switch (pmsg->message_id) {
+    case MSG_SORT:
+      OnSort();
+      break;
+    case MSG_PING:
+      OnPing();
+      break;
+    default:
+      ASSERT(false);
+      break;
+  }
+}
+
+// Handle queued up sort request
+void P2PTransportChannel::OnSort() {
+  // Resort the connections based on the new statistics.
+  SortConnections();
+}
+
+// Handle queued up ping request
+void P2PTransportChannel::OnPing() {
+  // Make sure the states of the connections are up-to-date (since this affects
+  // which ones are pingable).
+  UpdateConnectionStates();
+
+  // Find the oldest pingable connection and have it do a ping.
+  Connection* conn = FindNextPingableConnection();
+  if (conn)
+    PingConnection(conn);
+
+  // Post ourselves a message to perform the next ping.
+  uint32 delay = writable() ? WRITABLE_DELAY : UNWRITABLE_DELAY;
+  thread()->PostDelayed(delay, this, MSG_PING);
+}
+
+// Is the connection in a state for us to even consider pinging the other side?
+bool P2PTransportChannel::IsPingable(Connection* conn) {
+  // An unconnected connection cannot be written to at all, so pinging is out
+  // of the question.
+  if (!conn->connected())
+    return false;
+
+  if (writable()) {
+    // If we are writable, then we only want to ping connections that could be
+    // better than this one, i.e., the ones that were not pruned.
+    return (conn->write_state() != Connection::STATE_WRITE_TIMEOUT);
+  } else {
+    // If we are not writable, then we need to try everything that might work.
+    // This includes both connections that do not have write timeout as well as
+    // ones that do not have read timeout.  A connection could be readable but
+    // be in write-timeout if we pruned it before.  Since the other side is
+    // still pinging it, it very well might still work.
+    return (conn->write_state() != Connection::STATE_WRITE_TIMEOUT) ||
+           (conn->read_state() != Connection::STATE_READ_TIMEOUT);
+  }
+}
+
+// Returns the next pingable connection to ping.  This will be the oldest
+// pingable connection unless we have a writable connection that is past the
+// maximum acceptable ping delay.
+Connection* P2PTransportChannel::FindNextPingableConnection() {
+  uint32 now = rtc::Time();
+  if (best_connection_ &&
+      (best_connection_->write_state() == Connection::STATE_WRITABLE) &&
+      (best_connection_->last_ping_sent()
+       + MAX_CURRENT_WRITABLE_DELAY <= now)) {
+    return best_connection_;
+  }
+
+  Connection* oldest_conn = NULL;
+  uint32 oldest_time = 0xFFFFFFFF;
+  for (uint32 i = 0; i < connections_.size(); ++i) {
+    if (IsPingable(connections_[i])) {
+      if (connections_[i]->last_ping_sent() < oldest_time) {
+        oldest_time = connections_[i]->last_ping_sent();
+        oldest_conn = connections_[i];
+      }
+    }
+  }
+  return oldest_conn;
+}
+
+// Apart from sending ping from |conn| this method also updates
+// |use_candidate_attr| flag. The criteria to update this flag is
+// explained below.
+// Set USE-CANDIDATE if doing ICE AND this channel is in CONTROLLING AND
+//    a) Channel is in FULL ICE AND
+//      a.1) |conn| is the best connection OR
+//      a.2) there is no best connection OR
+//      a.3) the best connection is unwritable OR
+//      a.4) |conn| has higher priority than best_connection.
+//    b) we're doing LITE ICE AND
+//      b.1) |conn| is the best_connection AND
+//      b.2) |conn| is writable.
+void P2PTransportChannel::PingConnection(Connection* conn) {
+  bool use_candidate = false;
+  if (protocol_type_ == ICEPROTO_RFC5245) {
+    if (remote_ice_mode_ == ICEMODE_FULL && ice_role_ == ICEROLE_CONTROLLING) {
+      use_candidate = (conn == best_connection_) ||
+                      (best_connection_ == NULL) ||
+                      (!best_connection_->writable()) ||
+                      (conn->priority() > best_connection_->priority());
+    } else if (remote_ice_mode_ == ICEMODE_LITE && conn == best_connection_) {
+      use_candidate = best_connection_->writable();
+    }
+  }
+  conn->set_use_candidate_attr(use_candidate);
+  conn->Ping(rtc::Time());
+}
+
+// When a connection's state changes, we need to figure out who to use as
+// the best connection again.  It could have become usable, or become unusable.
+void P2PTransportChannel::OnConnectionStateChange(Connection* connection) {
+  ASSERT(worker_thread_ == rtc::Thread::Current());
+
+  // Update the best connection if the state change is from pending best
+  // connection and role is controlled.
+  if (protocol_type_ == ICEPROTO_RFC5245 && ice_role_ == ICEROLE_CONTROLLED) {
+    if (connection == pending_best_connection_ && connection->writable()) {
+      pending_best_connection_ = NULL;
+      SwitchBestConnectionTo(connection);
+    }
+  }
+
+  // We have to unroll the stack before doing this because we may be changing
+  // the state of connections while sorting.
+  RequestSort();
+}
+
+// When a connection is removed, edit it out, and then update our best
+// connection.
+void P2PTransportChannel::OnConnectionDestroyed(Connection* connection) {
+  ASSERT(worker_thread_ == rtc::Thread::Current());
+
+  // Note: the previous best_connection_ may be destroyed by now, so don't
+  // use it.
+
+  // Remove this connection from the list.
+  std::vector<Connection*>::iterator iter =
+      std::find(connections_.begin(), connections_.end(), connection);
+  ASSERT(iter != connections_.end());
+  connections_.erase(iter);
+
+  LOG_J(LS_INFO, this) << "Removed connection ("
+    << static_cast<int>(connections_.size()) << " remaining)";
+
+  if (pending_best_connection_ == connection) {
+    pending_best_connection_ = NULL;
+  }
+
+  // If this is currently the best connection, then we need to pick a new one.
+  // The call to SortConnections will pick a new one.  It looks at the current
+  // best connection in order to avoid switching between fairly similar ones.
+  // Since this connection is no longer an option, we can just set best to NULL
+  // and re-choose a best assuming that there was no best connection.
+  if (best_connection_ == connection) {
+    SwitchBestConnectionTo(NULL);
+    RequestSort();
+  }
+
+  SignalConnectionRemoved(this);
+}
+
+// When a port is destroyed remove it from our list of ports to use for
+// connection attempts.
+void P2PTransportChannel::OnPortDestroyed(PortInterface* port) {
+  ASSERT(worker_thread_ == rtc::Thread::Current());
+
+  // Remove this port from the list (if we didn't drop it already).
+  std::vector<PortInterface*>::iterator iter =
+      std::find(ports_.begin(), ports_.end(), port);
+  if (iter != ports_.end())
+    ports_.erase(iter);
+
+  LOG(INFO) << "Removed port from p2p socket: "
+            << static_cast<int>(ports_.size()) << " remaining";
+}
+
+// We data is available, let listeners know
+void P2PTransportChannel::OnReadPacket(
+    Connection *connection, const char *data, size_t len,
+    const rtc::PacketTime& packet_time) {
+  ASSERT(worker_thread_ == rtc::Thread::Current());
+
+  // Do not deliver, if packet doesn't belong to the correct transport channel.
+  if (!FindConnection(connection))
+    return;
+
+  // Let the client know of an incoming packet
+  SignalReadPacket(this, data, len, packet_time, 0);
+}
+
+void P2PTransportChannel::OnReadyToSend(Connection* connection) {
+  if (connection == best_connection_ && writable()) {
+    SignalReadyToSend(this);
+  }
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/p2ptransportchannel.h b/webrtc/p2p/base/p2ptransportchannel.h
new file mode 100644
index 0000000..8e3d50d
--- /dev/null
+++ b/webrtc/p2p/base/p2ptransportchannel.h
@@ -0,0 +1,242 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+// P2PTransportChannel wraps up the state management of the connection between
+// two P2P clients.  Clients have candidate ports for connecting, and
+// connections which are combinations of candidates from each end (Alice and
+// Bob each have candidates, one candidate from Alice and one candidate from
+// Bob are used to make a connection, repeat to make many connections).
+//
+// When all of the available connections become invalid (non-writable), we
+// kick off a process of determining more candidates and more connections.
+//
+#ifndef WEBRTC_P2P_BASE_P2PTRANSPORTCHANNEL_H_
+#define WEBRTC_P2P_BASE_P2PTRANSPORTCHANNEL_H_
+
+#include <map>
+#include <string>
+#include <vector>
+#include "webrtc/p2p/base/candidate.h"
+#include "webrtc/p2p/base/p2ptransport.h"
+#include "webrtc/p2p/base/portallocator.h"
+#include "webrtc/p2p/base/portinterface.h"
+#include "webrtc/p2p/base/transport.h"
+#include "webrtc/p2p/base/transportchannelimpl.h"
+#include "webrtc/base/asyncpacketsocket.h"
+#include "webrtc/base/sigslot.h"
+
+namespace cricket {
+
+// Adds the port on which the candidate originated.
+class RemoteCandidate : public Candidate {
+ public:
+  RemoteCandidate(const Candidate& c, PortInterface* origin_port)
+      : Candidate(c), origin_port_(origin_port) {}
+
+  PortInterface* origin_port() { return origin_port_; }
+
+ private:
+  PortInterface* origin_port_;
+};
+
+// P2PTransportChannel manages the candidates and connection process to keep
+// two P2P clients connected to each other.
+class P2PTransportChannel : public TransportChannelImpl,
+                            public rtc::MessageHandler {
+ public:
+  P2PTransportChannel(const std::string& content_name,
+                      int component,
+                      P2PTransport* transport,
+                      PortAllocator *allocator);
+  virtual ~P2PTransportChannel();
+
+  // From TransportChannelImpl:
+  virtual Transport* GetTransport() { return transport_; }
+  virtual void SetIceRole(IceRole role);
+  virtual IceRole GetIceRole() const { return ice_role_; }
+  virtual void SetIceTiebreaker(uint64 tiebreaker);
+  virtual size_t GetConnectionCount() const { return connections_.size(); }
+  virtual bool GetIceProtocolType(IceProtocolType* type) const;
+  virtual void SetIceProtocolType(IceProtocolType type);
+  virtual void SetIceCredentials(const std::string& ice_ufrag,
+                                 const std::string& ice_pwd);
+  virtual void SetRemoteIceCredentials(const std::string& ice_ufrag,
+                                       const std::string& ice_pwd);
+  virtual void SetRemoteIceMode(IceMode mode);
+  virtual void Connect();
+  virtual void Reset();
+  virtual void OnSignalingReady();
+  virtual void OnCandidate(const Candidate& candidate);
+
+  // From TransportChannel:
+  virtual int SendPacket(const char *data, size_t len,
+                         const rtc::PacketOptions& options, int flags);
+  virtual int SetOption(rtc::Socket::Option opt, int value);
+  virtual int GetError() { return error_; }
+  virtual bool GetStats(std::vector<ConnectionInfo>* stats);
+
+  const Connection* best_connection() const { return best_connection_; }
+  void set_incoming_only(bool value) { incoming_only_ = value; }
+
+  // Note: This is only for testing purpose.
+  // |ports_| should not be changed from outside.
+  const std::vector<PortInterface *>& ports() { return ports_; }
+
+  IceMode remote_ice_mode() const { return remote_ice_mode_; }
+
+  // DTLS methods.
+  virtual bool IsDtlsActive() const { return false; }
+
+  // Default implementation.
+  virtual bool GetSslRole(rtc::SSLRole* role) const {
+    return false;
+  }
+
+  virtual bool SetSslRole(rtc::SSLRole role) {
+    return false;
+  }
+
+  // Set up the ciphers to use for DTLS-SRTP.
+  virtual bool SetSrtpCiphers(const std::vector<std::string>& ciphers) {
+    return false;
+  }
+
+  // Find out which DTLS-SRTP cipher was negotiated
+  virtual bool GetSrtpCipher(std::string* cipher) {
+    return false;
+  }
+
+  // Returns false because the channel is not encrypted by default.
+  virtual bool GetLocalIdentity(rtc::SSLIdentity** identity) const {
+    return false;
+  }
+
+  virtual bool GetRemoteCertificate(rtc::SSLCertificate** cert) const {
+    return false;
+  }
+
+  // Allows key material to be extracted for external encryption.
+  virtual bool ExportKeyingMaterial(
+      const std::string& label,
+      const uint8* context,
+      size_t context_len,
+      bool use_context,
+      uint8* result,
+      size_t result_len) {
+    return false;
+  }
+
+  virtual bool SetLocalIdentity(rtc::SSLIdentity* identity) {
+    return false;
+  }
+
+  // Set DTLS Remote fingerprint. Must be after local identity set.
+  virtual bool SetRemoteFingerprint(
+    const std::string& digest_alg,
+    const uint8* digest,
+    size_t digest_len) {
+    return false;
+  }
+
+  // Helper method used only in unittest.
+  rtc::DiffServCodePoint DefaultDscpValue() const;
+
+ private:
+  rtc::Thread* thread() { return worker_thread_; }
+  PortAllocatorSession* allocator_session() {
+    return allocator_sessions_.back();
+  }
+
+  void Allocate();
+  void UpdateConnectionStates();
+  void RequestSort();
+  void SortConnections();
+  void SwitchBestConnectionTo(Connection* conn);
+  void UpdateChannelState();
+  void HandleWritable();
+  void HandleNotWritable();
+  void HandleAllTimedOut();
+
+  Connection* GetBestConnectionOnNetwork(rtc::Network* network);
+  bool CreateConnections(const Candidate &remote_candidate,
+                         PortInterface* origin_port, bool readable);
+  bool CreateConnection(PortInterface* port, const Candidate& remote_candidate,
+                        PortInterface* origin_port, bool readable);
+  bool FindConnection(cricket::Connection* connection) const;
+
+  uint32 GetRemoteCandidateGeneration(const Candidate& candidate);
+  bool IsDuplicateRemoteCandidate(const Candidate& candidate);
+  void RememberRemoteCandidate(const Candidate& remote_candidate,
+                               PortInterface* origin_port);
+  bool IsPingable(Connection* conn);
+  Connection* FindNextPingableConnection();
+  void PingConnection(Connection* conn);
+  void AddAllocatorSession(PortAllocatorSession* session);
+  void AddConnection(Connection* connection);
+
+  void OnPortReady(PortAllocatorSession *session, PortInterface* port);
+  void OnCandidatesReady(PortAllocatorSession *session,
+                         const std::vector<Candidate>& candidates);
+  void OnCandidatesAllocationDone(PortAllocatorSession* session);
+  void OnUnknownAddress(PortInterface* port,
+                        const rtc::SocketAddress& addr,
+                        ProtocolType proto,
+                        IceMessage* stun_msg,
+                        const std::string& remote_username,
+                        bool port_muxed);
+  void OnPortDestroyed(PortInterface* port);
+  void OnRoleConflict(PortInterface* port);
+
+  void OnConnectionStateChange(Connection* connection);
+  void OnReadPacket(Connection *connection, const char *data, size_t len,
+                    const rtc::PacketTime& packet_time);
+  void OnReadyToSend(Connection* connection);
+  void OnConnectionDestroyed(Connection *connection);
+
+  void OnUseCandidate(Connection* conn);
+
+  virtual void OnMessage(rtc::Message *pmsg);
+  void OnSort();
+  void OnPing();
+
+  P2PTransport* transport_;
+  PortAllocator *allocator_;
+  rtc::Thread *worker_thread_;
+  bool incoming_only_;
+  bool waiting_for_signaling_;
+  int error_;
+  std::vector<PortAllocatorSession*> allocator_sessions_;
+  std::vector<PortInterface *> ports_;
+  std::vector<Connection *> connections_;
+  Connection* best_connection_;
+  // Connection selected by the controlling agent. This should be used only
+  // at controlled side when protocol type is RFC5245.
+  Connection* pending_best_connection_;
+  std::vector<RemoteCandidate> remote_candidates_;
+  bool sort_dirty_;  // indicates whether another sort is needed right now
+  bool was_writable_;
+  typedef std::map<rtc::Socket::Option, int> OptionMap;
+  OptionMap options_;
+  std::string ice_ufrag_;
+  std::string ice_pwd_;
+  std::string remote_ice_ufrag_;
+  std::string remote_ice_pwd_;
+  IceProtocolType protocol_type_;
+  IceMode remote_ice_mode_;
+  IceRole ice_role_;
+  uint64 tiebreaker_;
+  uint32 remote_candidate_generation_;
+
+  DISALLOW_EVIL_CONSTRUCTORS(P2PTransportChannel);
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_P2PTRANSPORTCHANNEL_H_
diff --git a/webrtc/p2p/base/p2ptransportchannel_unittest.cc b/webrtc/p2p/base/p2ptransportchannel_unittest.cc
new file mode 100644
index 0000000..4f32719
--- /dev/null
+++ b/webrtc/p2p/base/p2ptransportchannel_unittest.cc
@@ -0,0 +1,1702 @@
+/*
+ *  Copyright 2009 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/p2ptransportchannel.h"
+#include "webrtc/p2p/base/testrelayserver.h"
+#include "webrtc/p2p/base/teststunserver.h"
+#include "webrtc/p2p/base/testturnserver.h"
+#include "webrtc/p2p/client/basicportallocator.h"
+#include "webrtc/base/dscp.h"
+#include "webrtc/base/fakenetwork.h"
+#include "webrtc/base/firewallsocketserver.h"
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/helpers.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/natserver.h"
+#include "webrtc/base/natsocketfactory.h"
+#include "webrtc/base/physicalsocketserver.h"
+#include "webrtc/base/proxyserver.h"
+#include "webrtc/base/socketaddress.h"
+#include "webrtc/base/ssladapter.h"
+#include "webrtc/base/thread.h"
+#include "webrtc/base/virtualsocketserver.h"
+
+using cricket::kDefaultPortAllocatorFlags;
+using cricket::kMinimumStepDelay;
+using cricket::kDefaultStepDelay;
+using cricket::PORTALLOCATOR_ENABLE_SHARED_UFRAG;
+using cricket::PORTALLOCATOR_ENABLE_SHARED_SOCKET;
+using cricket::ServerAddresses;
+using rtc::SocketAddress;
+
+static const int kDefaultTimeout = 1000;
+static const int kOnlyLocalPorts = cricket::PORTALLOCATOR_DISABLE_STUN |
+                                   cricket::PORTALLOCATOR_DISABLE_RELAY |
+                                   cricket::PORTALLOCATOR_DISABLE_TCP;
+// Addresses on the public internet.
+static const SocketAddress kPublicAddrs[2] =
+    { SocketAddress("11.11.11.11", 0), SocketAddress("22.22.22.22", 0) };
+// IPv6 Addresses on the public internet.
+static const SocketAddress kIPv6PublicAddrs[2] = {
+    SocketAddress("2400:4030:1:2c00:be30:abcd:efab:cdef", 0),
+    SocketAddress("2620:0:1000:1b03:2e41:38ff:fea6:f2a4", 0)
+};
+// For configuring multihomed clients.
+static const SocketAddress kAlternateAddrs[2] =
+    { SocketAddress("11.11.11.101", 0), SocketAddress("22.22.22.202", 0) };
+// Addresses for HTTP proxy servers.
+static const SocketAddress kHttpsProxyAddrs[2] =
+    { SocketAddress("11.11.11.1", 443), SocketAddress("22.22.22.1", 443) };
+// Addresses for SOCKS proxy servers.
+static const SocketAddress kSocksProxyAddrs[2] =
+    { SocketAddress("11.11.11.1", 1080), SocketAddress("22.22.22.1", 1080) };
+// Internal addresses for NAT boxes.
+static const SocketAddress kNatAddrs[2] =
+    { SocketAddress("192.168.1.1", 0), SocketAddress("192.168.2.1", 0) };
+// Private addresses inside the NAT private networks.
+static const SocketAddress kPrivateAddrs[2] =
+    { SocketAddress("192.168.1.11", 0), SocketAddress("192.168.2.22", 0) };
+// For cascaded NATs, the internal addresses of the inner NAT boxes.
+static const SocketAddress kCascadedNatAddrs[2] =
+    { SocketAddress("192.168.10.1", 0), SocketAddress("192.168.20.1", 0) };
+// For cascaded NATs, private addresses inside the inner private networks.
+static const SocketAddress kCascadedPrivateAddrs[2] =
+    { SocketAddress("192.168.10.11", 0), SocketAddress("192.168.20.22", 0) };
+// The address of the public STUN server.
+static const SocketAddress kStunAddr("99.99.99.1", cricket::STUN_SERVER_PORT);
+// The addresses for the public relay server.
+static const SocketAddress kRelayUdpIntAddr("99.99.99.2", 5000);
+static const SocketAddress kRelayUdpExtAddr("99.99.99.3", 5001);
+static const SocketAddress kRelayTcpIntAddr("99.99.99.2", 5002);
+static const SocketAddress kRelayTcpExtAddr("99.99.99.3", 5003);
+static const SocketAddress kRelaySslTcpIntAddr("99.99.99.2", 5004);
+static const SocketAddress kRelaySslTcpExtAddr("99.99.99.3", 5005);
+// The addresses for the public turn server.
+static const SocketAddress kTurnUdpIntAddr("99.99.99.4",
+                                           cricket::STUN_SERVER_PORT);
+static const SocketAddress kTurnUdpExtAddr("99.99.99.5", 0);
+static const cricket::RelayCredentials kRelayCredentials("test", "test");
+
+// Based on ICE_UFRAG_LENGTH
+static const char* kIceUfrag[4] = {"TESTICEUFRAG0000", "TESTICEUFRAG0001",
+                                   "TESTICEUFRAG0002", "TESTICEUFRAG0003"};
+// Based on ICE_PWD_LENGTH
+static const char* kIcePwd[4] = {"TESTICEPWD00000000000000",
+                                 "TESTICEPWD00000000000001",
+                                 "TESTICEPWD00000000000002",
+                                 "TESTICEPWD00000000000003"};
+
+static const uint64 kTiebreaker1 = 11111;
+static const uint64 kTiebreaker2 = 22222;
+
+// This test simulates 2 P2P endpoints that want to establish connectivity
+// with each other over various network topologies and conditions, which can be
+// specified in each individial test.
+// A virtual network (via VirtualSocketServer) along with virtual firewalls and
+// NATs (via Firewall/NATSocketServer) are used to simulate the various network
+// conditions. We can configure the IP addresses of the endpoints,
+// block various types of connectivity, or add arbitrary levels of NAT.
+// We also run a STUN server and a relay server on the virtual network to allow
+// our typical P2P mechanisms to do their thing.
+// For each case, we expect the P2P stack to eventually settle on a specific
+// form of connectivity to the other side. The test checks that the P2P
+// negotiation successfully establishes connectivity within a certain time,
+// and that the result is what we expect.
+// Note that this class is a base class for use by other tests, who will provide
+// specialized test behavior.
+class P2PTransportChannelTestBase : public testing::Test,
+                                    public rtc::MessageHandler,
+                                    public sigslot::has_slots<> {
+ public:
+  P2PTransportChannelTestBase()
+      : main_(rtc::Thread::Current()),
+        pss_(new rtc::PhysicalSocketServer),
+        vss_(new rtc::VirtualSocketServer(pss_.get())),
+        nss_(new rtc::NATSocketServer(vss_.get())),
+        ss_(new rtc::FirewallSocketServer(nss_.get())),
+        ss_scope_(ss_.get()),
+        stun_server_(cricket::TestStunServer::Create(main_, kStunAddr)),
+        turn_server_(main_, kTurnUdpIntAddr, kTurnUdpExtAddr),
+        relay_server_(main_, kRelayUdpIntAddr, kRelayUdpExtAddr,
+                      kRelayTcpIntAddr, kRelayTcpExtAddr,
+                      kRelaySslTcpIntAddr, kRelaySslTcpExtAddr),
+        socks_server1_(ss_.get(), kSocksProxyAddrs[0],
+                       ss_.get(), kSocksProxyAddrs[0]),
+        socks_server2_(ss_.get(), kSocksProxyAddrs[1],
+                       ss_.get(), kSocksProxyAddrs[1]),
+        clear_remote_candidates_ufrag_pwd_(false),
+        force_relay_(false) {
+    ep1_.role_ = cricket::ICEROLE_CONTROLLING;
+    ep2_.role_ = cricket::ICEROLE_CONTROLLED;
+
+    ServerAddresses stun_servers;
+    stun_servers.insert(kStunAddr);
+    ep1_.allocator_.reset(new cricket::BasicPortAllocator(
+        &ep1_.network_manager_,
+        stun_servers, kRelayUdpIntAddr, kRelayTcpIntAddr, kRelaySslTcpIntAddr));
+    ep2_.allocator_.reset(new cricket::BasicPortAllocator(
+        &ep2_.network_manager_,
+        stun_servers, kRelayUdpIntAddr, kRelayTcpIntAddr, kRelaySslTcpIntAddr));
+  }
+
+ protected:
+  enum Config {
+    OPEN,                           // Open to the Internet
+    NAT_FULL_CONE,                  // NAT, no filtering
+    NAT_ADDR_RESTRICTED,            // NAT, must send to an addr to recv
+    NAT_PORT_RESTRICTED,            // NAT, must send to an addr+port to recv
+    NAT_SYMMETRIC,                  // NAT, endpoint-dependent bindings
+    NAT_DOUBLE_CONE,                // Double NAT, both cone
+    NAT_SYMMETRIC_THEN_CONE,        // Double NAT, symmetric outer, cone inner
+    BLOCK_UDP,                      // Firewall, UDP in/out blocked
+    BLOCK_UDP_AND_INCOMING_TCP,     // Firewall, UDP in/out and TCP in blocked
+    BLOCK_ALL_BUT_OUTGOING_HTTP,    // Firewall, only TCP out on 80/443
+    PROXY_HTTPS,                    // All traffic through HTTPS proxy
+    PROXY_SOCKS,                    // All traffic through SOCKS proxy
+    NUM_CONFIGS
+  };
+
+  struct Result {
+    Result(const std::string& lt, const std::string& lp,
+           const std::string& rt, const std::string& rp,
+           const std::string& lt2, const std::string& lp2,
+           const std::string& rt2, const std::string& rp2, int wait)
+        : local_type(lt), local_proto(lp), remote_type(rt), remote_proto(rp),
+          local_type2(lt2), local_proto2(lp2), remote_type2(rt2),
+          remote_proto2(rp2), connect_wait(wait) {
+    }
+    std::string local_type;
+    std::string local_proto;
+    std::string remote_type;
+    std::string remote_proto;
+    std::string local_type2;
+    std::string local_proto2;
+    std::string remote_type2;
+    std::string remote_proto2;
+    int connect_wait;
+  };
+
+  struct ChannelData {
+    bool CheckData(const char* data, int len) {
+      bool ret = false;
+      if (!ch_packets_.empty()) {
+        std::string packet =  ch_packets_.front();
+        ret = (packet == std::string(data, len));
+        ch_packets_.pop_front();
+      }
+      return ret;
+    }
+
+    std::string name_;  // TODO - Currently not used.
+    std::list<std::string> ch_packets_;
+    rtc::scoped_ptr<cricket::P2PTransportChannel> ch_;
+  };
+
+  struct Endpoint {
+    Endpoint() : signaling_delay_(0), role_(cricket::ICEROLE_UNKNOWN),
+        tiebreaker_(0), role_conflict_(false),
+        protocol_type_(cricket::ICEPROTO_GOOGLE) {}
+    bool HasChannel(cricket::TransportChannel* ch) {
+      return (ch == cd1_.ch_.get() || ch == cd2_.ch_.get());
+    }
+    ChannelData* GetChannelData(cricket::TransportChannel* ch) {
+      if (!HasChannel(ch)) return NULL;
+      if (cd1_.ch_.get() == ch)
+        return &cd1_;
+      else
+        return &cd2_;
+    }
+    void SetSignalingDelay(int delay) { signaling_delay_ = delay; }
+
+    void SetIceRole(cricket::IceRole role) { role_ = role; }
+    cricket::IceRole ice_role() { return role_; }
+    void SetIceProtocolType(cricket::IceProtocolType type) {
+      protocol_type_ = type;
+    }
+    cricket::IceProtocolType protocol_type() { return protocol_type_; }
+    void SetIceTiebreaker(uint64 tiebreaker) { tiebreaker_ = tiebreaker; }
+    uint64 GetIceTiebreaker() { return tiebreaker_; }
+    void OnRoleConflict(bool role_conflict) { role_conflict_ = role_conflict; }
+    bool role_conflict() { return role_conflict_; }
+    void SetAllocationStepDelay(uint32 delay) {
+      allocator_->set_step_delay(delay);
+    }
+    void SetAllowTcpListen(bool allow_tcp_listen) {
+      allocator_->set_allow_tcp_listen(allow_tcp_listen);
+    }
+
+    rtc::FakeNetworkManager network_manager_;
+    rtc::scoped_ptr<cricket::BasicPortAllocator> allocator_;
+    ChannelData cd1_;
+    ChannelData cd2_;
+    int signaling_delay_;
+    cricket::IceRole role_;
+    uint64 tiebreaker_;
+    bool role_conflict_;
+    cricket::IceProtocolType protocol_type_;
+  };
+
+  struct CandidateData : public rtc::MessageData {
+    CandidateData(cricket::TransportChannel* ch, const cricket::Candidate& c)
+        : channel(ch), candidate(c) {
+    }
+    cricket::TransportChannel* channel;
+    cricket::Candidate candidate;
+  };
+
+  ChannelData* GetChannelData(cricket::TransportChannel* channel) {
+    if (ep1_.HasChannel(channel))
+      return ep1_.GetChannelData(channel);
+    else
+      return ep2_.GetChannelData(channel);
+  }
+
+  void CreateChannels(int num) {
+    std::string ice_ufrag_ep1_cd1_ch = kIceUfrag[0];
+    std::string ice_pwd_ep1_cd1_ch = kIcePwd[0];
+    std::string ice_ufrag_ep2_cd1_ch = kIceUfrag[1];
+    std::string ice_pwd_ep2_cd1_ch = kIcePwd[1];
+    ep1_.cd1_.ch_.reset(CreateChannel(
+        0, cricket::ICE_CANDIDATE_COMPONENT_DEFAULT,
+        ice_ufrag_ep1_cd1_ch, ice_pwd_ep1_cd1_ch,
+        ice_ufrag_ep2_cd1_ch, ice_pwd_ep2_cd1_ch));
+    ep2_.cd1_.ch_.reset(CreateChannel(
+        1, cricket::ICE_CANDIDATE_COMPONENT_DEFAULT,
+        ice_ufrag_ep2_cd1_ch, ice_pwd_ep2_cd1_ch,
+        ice_ufrag_ep1_cd1_ch, ice_pwd_ep1_cd1_ch));
+    if (num == 2) {
+      std::string ice_ufrag_ep1_cd2_ch = kIceUfrag[2];
+      std::string ice_pwd_ep1_cd2_ch = kIcePwd[2];
+      std::string ice_ufrag_ep2_cd2_ch = kIceUfrag[3];
+      std::string ice_pwd_ep2_cd2_ch = kIcePwd[3];
+      // In BUNDLE each endpoint must share common ICE credentials.
+      if (ep1_.allocator_->flags() & cricket::PORTALLOCATOR_ENABLE_BUNDLE) {
+        ice_ufrag_ep1_cd2_ch = ice_ufrag_ep1_cd1_ch;
+        ice_pwd_ep1_cd2_ch = ice_pwd_ep1_cd1_ch;
+      }
+      if (ep2_.allocator_->flags() & cricket::PORTALLOCATOR_ENABLE_BUNDLE) {
+        ice_ufrag_ep2_cd2_ch = ice_ufrag_ep2_cd1_ch;
+        ice_pwd_ep2_cd2_ch = ice_pwd_ep2_cd1_ch;
+      }
+      ep1_.cd2_.ch_.reset(CreateChannel(
+          0, cricket::ICE_CANDIDATE_COMPONENT_DEFAULT,
+          ice_ufrag_ep1_cd2_ch, ice_pwd_ep1_cd2_ch,
+          ice_ufrag_ep2_cd2_ch, ice_pwd_ep2_cd2_ch));
+      ep2_.cd2_.ch_.reset(CreateChannel(
+          1, cricket::ICE_CANDIDATE_COMPONENT_DEFAULT,
+          ice_ufrag_ep2_cd2_ch, ice_pwd_ep2_cd2_ch,
+          ice_ufrag_ep1_cd2_ch, ice_pwd_ep1_cd2_ch));
+    }
+  }
+  cricket::P2PTransportChannel* CreateChannel(
+      int endpoint,
+      int component,
+      const std::string& local_ice_ufrag,
+      const std::string& local_ice_pwd,
+      const std::string& remote_ice_ufrag,
+      const std::string& remote_ice_pwd) {
+    cricket::P2PTransportChannel* channel = new cricket::P2PTransportChannel(
+        "test content name", component, NULL, GetAllocator(endpoint));
+    channel->SignalRequestSignaling.connect(
+        this, &P2PTransportChannelTestBase::OnChannelRequestSignaling);
+    channel->SignalCandidateReady.connect(this,
+        &P2PTransportChannelTestBase::OnCandidate);
+    channel->SignalReadPacket.connect(
+        this, &P2PTransportChannelTestBase::OnReadPacket);
+    channel->SignalRoleConflict.connect(
+        this, &P2PTransportChannelTestBase::OnRoleConflict);
+    channel->SetIceProtocolType(GetEndpoint(endpoint)->protocol_type());
+    channel->SetIceCredentials(local_ice_ufrag, local_ice_pwd);
+    if (clear_remote_candidates_ufrag_pwd_) {
+      // This only needs to be set if we're clearing them from the
+      // candidates.  Some unit tests rely on this not being set.
+      channel->SetRemoteIceCredentials(remote_ice_ufrag, remote_ice_pwd);
+    }
+    channel->SetIceRole(GetEndpoint(endpoint)->ice_role());
+    channel->SetIceTiebreaker(GetEndpoint(endpoint)->GetIceTiebreaker());
+    channel->Connect();
+    return channel;
+  }
+  void DestroyChannels() {
+    ep1_.cd1_.ch_.reset();
+    ep2_.cd1_.ch_.reset();
+    ep1_.cd2_.ch_.reset();
+    ep2_.cd2_.ch_.reset();
+  }
+  cricket::P2PTransportChannel* ep1_ch1() { return ep1_.cd1_.ch_.get(); }
+  cricket::P2PTransportChannel* ep1_ch2() { return ep1_.cd2_.ch_.get(); }
+  cricket::P2PTransportChannel* ep2_ch1() { return ep2_.cd1_.ch_.get(); }
+  cricket::P2PTransportChannel* ep2_ch2() { return ep2_.cd2_.ch_.get(); }
+
+  // Common results.
+  static const Result kLocalUdpToLocalUdp;
+  static const Result kLocalUdpToStunUdp;
+  static const Result kLocalUdpToPrflxUdp;
+  static const Result kPrflxUdpToLocalUdp;
+  static const Result kStunUdpToLocalUdp;
+  static const Result kStunUdpToStunUdp;
+  static const Result kPrflxUdpToStunUdp;
+  static const Result kLocalUdpToRelayUdp;
+  static const Result kPrflxUdpToRelayUdp;
+  static const Result kLocalTcpToLocalTcp;
+  static const Result kLocalTcpToPrflxTcp;
+  static const Result kPrflxTcpToLocalTcp;
+
+  rtc::NATSocketServer* nat() { return nss_.get(); }
+  rtc::FirewallSocketServer* fw() { return ss_.get(); }
+
+  Endpoint* GetEndpoint(int endpoint) {
+    if (endpoint == 0) {
+      return &ep1_;
+    } else if (endpoint == 1) {
+      return &ep2_;
+    } else {
+      return NULL;
+    }
+  }
+  cricket::PortAllocator* GetAllocator(int endpoint) {
+    return GetEndpoint(endpoint)->allocator_.get();
+  }
+  void AddAddress(int endpoint, const SocketAddress& addr) {
+    GetEndpoint(endpoint)->network_manager_.AddInterface(addr);
+  }
+  void RemoveAddress(int endpoint, const SocketAddress& addr) {
+    GetEndpoint(endpoint)->network_manager_.RemoveInterface(addr);
+  }
+  void SetProxy(int endpoint, rtc::ProxyType type) {
+    rtc::ProxyInfo info;
+    info.type = type;
+    info.address = (type == rtc::PROXY_HTTPS) ?
+        kHttpsProxyAddrs[endpoint] : kSocksProxyAddrs[endpoint];
+    GetAllocator(endpoint)->set_proxy("unittest/1.0", info);
+  }
+  void SetAllocatorFlags(int endpoint, int flags) {
+    GetAllocator(endpoint)->set_flags(flags);
+  }
+  void SetSignalingDelay(int endpoint, int delay) {
+    GetEndpoint(endpoint)->SetSignalingDelay(delay);
+  }
+  void SetIceProtocol(int endpoint, cricket::IceProtocolType type) {
+    GetEndpoint(endpoint)->SetIceProtocolType(type);
+  }
+  void SetIceRole(int endpoint, cricket::IceRole role) {
+    GetEndpoint(endpoint)->SetIceRole(role);
+  }
+  void SetIceTiebreaker(int endpoint, uint64 tiebreaker) {
+    GetEndpoint(endpoint)->SetIceTiebreaker(tiebreaker);
+  }
+  bool GetRoleConflict(int endpoint) {
+    return GetEndpoint(endpoint)->role_conflict();
+  }
+  void SetAllocationStepDelay(int endpoint, uint32 delay) {
+    return GetEndpoint(endpoint)->SetAllocationStepDelay(delay);
+  }
+  void SetAllowTcpListen(int endpoint, bool allow_tcp_listen) {
+    return GetEndpoint(endpoint)->SetAllowTcpListen(allow_tcp_listen);
+  }
+
+  void Test(const Result& expected) {
+    int32 connect_start = rtc::Time(), connect_time;
+
+    // Create the channels and wait for them to connect.
+    CreateChannels(1);
+    EXPECT_TRUE_WAIT_MARGIN(ep1_ch1() != NULL &&
+                            ep2_ch1() != NULL &&
+                            ep1_ch1()->readable() &&
+                            ep1_ch1()->writable() &&
+                            ep2_ch1()->readable() &&
+                            ep2_ch1()->writable(),
+                            expected.connect_wait,
+                            1000);
+    connect_time = rtc::TimeSince(connect_start);
+    if (connect_time < expected.connect_wait) {
+      LOG(LS_INFO) << "Connect time: " << connect_time << " ms";
+    } else {
+      LOG(LS_INFO) << "Connect time: " << "TIMEOUT ("
+                   << expected.connect_wait << " ms)";
+    }
+
+    // Allow a few turns of the crank for the best connections to emerge.
+    // This may take up to 2 seconds.
+    if (ep1_ch1()->best_connection() &&
+        ep2_ch1()->best_connection()) {
+      int32 converge_start = rtc::Time(), converge_time;
+      int converge_wait = 2000;
+      EXPECT_TRUE_WAIT_MARGIN(
+          LocalCandidate(ep1_ch1())->type() == expected.local_type &&
+          LocalCandidate(ep1_ch1())->protocol() == expected.local_proto &&
+          RemoteCandidate(ep1_ch1())->type() == expected.remote_type &&
+          RemoteCandidate(ep1_ch1())->protocol() == expected.remote_proto,
+          converge_wait,
+          converge_wait);
+
+      // Also do EXPECT_EQ on each part so that failures are more verbose.
+      EXPECT_EQ(expected.local_type, LocalCandidate(ep1_ch1())->type());
+      EXPECT_EQ(expected.local_proto, LocalCandidate(ep1_ch1())->protocol());
+      EXPECT_EQ(expected.remote_type, RemoteCandidate(ep1_ch1())->type());
+      EXPECT_EQ(expected.remote_proto, RemoteCandidate(ep1_ch1())->protocol());
+
+      // Verifying remote channel best connection information. This is done
+      // only for the RFC 5245 as controlled agent will use USE-CANDIDATE
+      // from controlling (ep1) agent. We can easily predict from EP1 result
+      // matrix.
+      if (ep2_.protocol_type_ == cricket::ICEPROTO_RFC5245) {
+        // Checking for best connection candidates information at remote.
+        EXPECT_TRUE_WAIT(
+            LocalCandidate(ep2_ch1())->type() == expected.local_type2 &&
+            LocalCandidate(ep2_ch1())->protocol() == expected.local_proto2 &&
+            RemoteCandidate(ep2_ch1())->protocol() == expected.remote_proto2,
+            kDefaultTimeout);
+
+        // For verbose
+        EXPECT_EQ(expected.local_type2, LocalCandidate(ep2_ch1())->type());
+        EXPECT_EQ(expected.local_proto2, LocalCandidate(ep2_ch1())->protocol());
+        EXPECT_EQ(expected.remote_proto2,
+                  RemoteCandidate(ep2_ch1())->protocol());
+        // Removed remote_type comparision aginst best connection remote
+        // candidate. This is done to handle remote type discrepancy from
+        // local to stun based on the test type.
+        // For example in case of Open -> NAT, ep2 channels will have LULU
+        // and in other cases like NAT -> NAT it will be LUSU. To avoid these
+        // mismatches and we are doing comparision in different way.
+        // i.e. when don't match its remote type is either local or stun.
+        // TODO(ronghuawu): Refine the test criteria.
+        // https://code.google.com/p/webrtc/issues/detail?id=1953
+        if (expected.remote_type2 != RemoteCandidate(ep2_ch1())->type()) {
+          EXPECT_TRUE(expected.remote_type2 == cricket::LOCAL_PORT_TYPE ||
+                      expected.remote_type2 == cricket::STUN_PORT_TYPE);
+          EXPECT_TRUE(
+              RemoteCandidate(ep2_ch1())->type() == cricket::LOCAL_PORT_TYPE ||
+              RemoteCandidate(ep2_ch1())->type() == cricket::STUN_PORT_TYPE ||
+              RemoteCandidate(ep2_ch1())->type() == cricket::PRFLX_PORT_TYPE);
+        }
+      }
+
+      converge_time = rtc::TimeSince(converge_start);
+      if (converge_time < converge_wait) {
+        LOG(LS_INFO) << "Converge time: " << converge_time << " ms";
+      } else {
+        LOG(LS_INFO) << "Converge time: " << "TIMEOUT ("
+                     << converge_wait << " ms)";
+      }
+    }
+    // Try sending some data to other end.
+    TestSendRecv(1);
+
+    // Destroy the channels, and wait for them to be fully cleaned up.
+    DestroyChannels();
+  }
+
+  void TestSendRecv(int channels) {
+    for (int i = 0; i < 10; ++i) {
+    const char* data = "ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
+      int len = static_cast<int>(strlen(data));
+      // local_channel1 <==> remote_channel1
+      EXPECT_EQ_WAIT(len, SendData(ep1_ch1(), data, len), 1000);
+      EXPECT_TRUE_WAIT(CheckDataOnChannel(ep2_ch1(), data, len), 1000);
+      EXPECT_EQ_WAIT(len, SendData(ep2_ch1(), data, len), 1000);
+      EXPECT_TRUE_WAIT(CheckDataOnChannel(ep1_ch1(), data, len), 1000);
+      if (channels == 2 && ep1_ch2() && ep2_ch2()) {
+        // local_channel2 <==> remote_channel2
+        EXPECT_EQ_WAIT(len, SendData(ep1_ch2(), data, len), 1000);
+        EXPECT_TRUE_WAIT(CheckDataOnChannel(ep2_ch2(), data, len), 1000);
+        EXPECT_EQ_WAIT(len, SendData(ep2_ch2(), data, len), 1000);
+        EXPECT_TRUE_WAIT(CheckDataOnChannel(ep1_ch2(), data, len), 1000);
+      }
+    }
+  }
+
+  // This test waits for the transport to become readable and writable on both
+  // end points. Once they are, the end points set new local ice credentials to
+  // restart the ice gathering. Finally it waits for the transport to select a
+  // new connection using the newly generated ice candidates.
+  // Before calling this function the end points must be configured.
+  void TestHandleIceUfragPasswordChanged() {
+    ep1_ch1()->SetRemoteIceCredentials(kIceUfrag[1], kIcePwd[1]);
+    ep2_ch1()->SetRemoteIceCredentials(kIceUfrag[0], kIcePwd[0]);
+    EXPECT_TRUE_WAIT_MARGIN(ep1_ch1()->readable() && ep1_ch1()->writable() &&
+                            ep2_ch1()->readable() && ep2_ch1()->writable(),
+                            1000, 1000);
+
+    const cricket::Candidate* old_local_candidate1 = LocalCandidate(ep1_ch1());
+    const cricket::Candidate* old_local_candidate2 = LocalCandidate(ep2_ch1());
+    const cricket::Candidate* old_remote_candidate1 =
+        RemoteCandidate(ep1_ch1());
+    const cricket::Candidate* old_remote_candidate2 =
+        RemoteCandidate(ep2_ch1());
+
+    ep1_ch1()->SetIceCredentials(kIceUfrag[2], kIcePwd[2]);
+    ep1_ch1()->SetRemoteIceCredentials(kIceUfrag[3], kIcePwd[3]);
+    ep2_ch1()->SetIceCredentials(kIceUfrag[3], kIcePwd[3]);
+    ep2_ch1()->SetRemoteIceCredentials(kIceUfrag[2], kIcePwd[2]);
+
+    EXPECT_TRUE_WAIT_MARGIN(LocalCandidate(ep1_ch1())->generation() !=
+                            old_local_candidate1->generation(),
+                            1000, 1000);
+    EXPECT_TRUE_WAIT_MARGIN(LocalCandidate(ep2_ch1())->generation() !=
+                            old_local_candidate2->generation(),
+                            1000, 1000);
+    EXPECT_TRUE_WAIT_MARGIN(RemoteCandidate(ep1_ch1())->generation() !=
+                            old_remote_candidate1->generation(),
+                            1000, 1000);
+    EXPECT_TRUE_WAIT_MARGIN(RemoteCandidate(ep2_ch1())->generation() !=
+                            old_remote_candidate2->generation(),
+                            1000, 1000);
+    EXPECT_EQ(1u, RemoteCandidate(ep2_ch1())->generation());
+    EXPECT_EQ(1u, RemoteCandidate(ep1_ch1())->generation());
+  }
+
+  void TestSignalRoleConflict() {
+    SetIceProtocol(0, cricket::ICEPROTO_RFC5245);
+    SetIceTiebreaker(0, kTiebreaker1);  // Default EP1 is in controlling state.
+
+    SetIceProtocol(1, cricket::ICEPROTO_RFC5245);
+    SetIceRole(1, cricket::ICEROLE_CONTROLLING);
+    SetIceTiebreaker(1, kTiebreaker2);
+
+    // Creating channels with both channels role set to CONTROLLING.
+    CreateChannels(1);
+    // Since both the channels initiated with controlling state and channel2
+    // has higher tiebreaker value, channel1 should receive SignalRoleConflict.
+    EXPECT_TRUE_WAIT(GetRoleConflict(0), 1000);
+    EXPECT_FALSE(GetRoleConflict(1));
+
+    EXPECT_TRUE_WAIT(ep1_ch1()->readable() &&
+                     ep1_ch1()->writable() &&
+                     ep2_ch1()->readable() &&
+                     ep2_ch1()->writable(),
+                     1000);
+
+    EXPECT_TRUE(ep1_ch1()->best_connection() &&
+                ep2_ch1()->best_connection());
+
+    TestSendRecv(1);
+  }
+
+  void TestHybridConnectivity(cricket::IceProtocolType proto) {
+    AddAddress(0, kPublicAddrs[0]);
+    AddAddress(1, kPublicAddrs[1]);
+
+    SetAllocationStepDelay(0, kMinimumStepDelay);
+    SetAllocationStepDelay(1, kMinimumStepDelay);
+
+    SetIceRole(0, cricket::ICEROLE_CONTROLLING);
+    SetIceProtocol(0, cricket::ICEPROTO_HYBRID);
+    SetIceTiebreaker(0, kTiebreaker1);
+    SetIceRole(1, cricket::ICEROLE_CONTROLLED);
+    SetIceProtocol(1, proto);
+    SetIceTiebreaker(1, kTiebreaker2);
+
+    CreateChannels(1);
+    // When channel is in hybrid and it's controlling agent, channel will
+    // receive ping request from the remote. Hence connection is readable.
+    // Since channel is in hybrid, it will not send any pings, so no writable
+    // connection. Since channel2 is in controlled state, it will not have
+    // any connections which are readable or writable, as it didn't received
+    // pings (or none) with USE-CANDIDATE attribute.
+    EXPECT_TRUE_WAIT(ep1_ch1()->readable(), 1000);
+
+    // Set real protocol type.
+    ep1_ch1()->SetIceProtocolType(proto);
+
+    // Channel should able to send ping requests and connections become writable
+    // in both directions.
+    EXPECT_TRUE_WAIT(ep1_ch1()->readable() && ep1_ch1()->writable() &&
+                     ep2_ch1()->readable() && ep2_ch1()->writable(),
+                     1000);
+    EXPECT_TRUE(
+        ep1_ch1()->best_connection() && ep2_ch1()->best_connection() &&
+        LocalCandidate(ep1_ch1())->address().EqualIPs(kPublicAddrs[0]) &&
+        RemoteCandidate(ep1_ch1())->address().EqualIPs(kPublicAddrs[1]));
+
+    TestSendRecv(1);
+    DestroyChannels();
+  }
+
+  void OnChannelRequestSignaling(cricket::TransportChannelImpl* channel) {
+    channel->OnSignalingReady();
+  }
+  // We pass the candidates directly to the other side.
+  void OnCandidate(cricket::TransportChannelImpl* ch,
+                   const cricket::Candidate& c) {
+    if (force_relay_ && c.type() != cricket::RELAY_PORT_TYPE)
+      return;
+
+    main_->PostDelayed(GetEndpoint(ch)->signaling_delay_, this, 0,
+                       new CandidateData(ch, c));
+  }
+  void OnMessage(rtc::Message* msg) {
+    rtc::scoped_ptr<CandidateData> data(
+        static_cast<CandidateData*>(msg->pdata));
+    cricket::P2PTransportChannel* rch = GetRemoteChannel(data->channel);
+    cricket::Candidate c = data->candidate;
+    if (clear_remote_candidates_ufrag_pwd_) {
+      c.set_username("");
+      c.set_password("");
+    }
+    LOG(LS_INFO) << "Candidate(" << data->channel->component() << "->"
+                 << rch->component() << "): " << c.type() << ", " << c.protocol()
+                 << ", " << c.address().ToString() << ", " << c.username()
+                 << ", " << c.generation();
+    rch->OnCandidate(c);
+  }
+  void OnReadPacket(cricket::TransportChannel* channel, const char* data,
+                    size_t len, const rtc::PacketTime& packet_time,
+                    int flags) {
+    std::list<std::string>& packets = GetPacketList(channel);
+    packets.push_front(std::string(data, len));
+  }
+  void OnRoleConflict(cricket::TransportChannelImpl* channel) {
+    GetEndpoint(channel)->OnRoleConflict(true);
+    cricket::IceRole new_role =
+        GetEndpoint(channel)->ice_role() == cricket::ICEROLE_CONTROLLING ?
+            cricket::ICEROLE_CONTROLLED : cricket::ICEROLE_CONTROLLING;
+    channel->SetIceRole(new_role);
+  }
+  int SendData(cricket::TransportChannel* channel,
+               const char* data, size_t len) {
+    rtc::PacketOptions options;
+    return channel->SendPacket(data, len, options, 0);
+  }
+  bool CheckDataOnChannel(cricket::TransportChannel* channel,
+                          const char* data, int len) {
+    return GetChannelData(channel)->CheckData(data, len);
+  }
+  static const cricket::Candidate* LocalCandidate(
+      cricket::P2PTransportChannel* ch) {
+    return (ch && ch->best_connection()) ?
+        &ch->best_connection()->local_candidate() : NULL;
+  }
+  static const cricket::Candidate* RemoteCandidate(
+      cricket::P2PTransportChannel* ch) {
+    return (ch && ch->best_connection()) ?
+        &ch->best_connection()->remote_candidate() : NULL;
+  }
+  Endpoint* GetEndpoint(cricket::TransportChannel* ch) {
+    if (ep1_.HasChannel(ch)) {
+      return &ep1_;
+    } else if (ep2_.HasChannel(ch)) {
+      return &ep2_;
+    } else {
+      return NULL;
+    }
+  }
+  cricket::P2PTransportChannel* GetRemoteChannel(
+      cricket::TransportChannel* ch) {
+    if (ch == ep1_ch1())
+      return ep2_ch1();
+    else if (ch == ep1_ch2())
+      return ep2_ch2();
+    else if (ch == ep2_ch1())
+      return ep1_ch1();
+    else if (ch == ep2_ch2())
+      return ep1_ch2();
+    else
+      return NULL;
+  }
+  std::list<std::string>& GetPacketList(cricket::TransportChannel* ch) {
+    return GetChannelData(ch)->ch_packets_;
+  }
+
+  void set_clear_remote_candidates_ufrag_pwd(bool clear) {
+    clear_remote_candidates_ufrag_pwd_ = clear;
+  }
+
+  void set_force_relay(bool relay) {
+    force_relay_ = relay;
+  }
+
+ private:
+  rtc::Thread* main_;
+  rtc::scoped_ptr<rtc::PhysicalSocketServer> pss_;
+  rtc::scoped_ptr<rtc::VirtualSocketServer> vss_;
+  rtc::scoped_ptr<rtc::NATSocketServer> nss_;
+  rtc::scoped_ptr<rtc::FirewallSocketServer> ss_;
+  rtc::SocketServerScope ss_scope_;
+  rtc::scoped_ptr<cricket::TestStunServer> stun_server_;
+  cricket::TestTurnServer turn_server_;
+  cricket::TestRelayServer relay_server_;
+  rtc::SocksProxyServer socks_server1_;
+  rtc::SocksProxyServer socks_server2_;
+  Endpoint ep1_;
+  Endpoint ep2_;
+  bool clear_remote_candidates_ufrag_pwd_;
+  bool force_relay_;
+};
+
+// The tests have only a few outcomes, which we predefine.
+const P2PTransportChannelTestBase::Result P2PTransportChannelTestBase::
+    kLocalUdpToLocalUdp("local", "udp", "local", "udp",
+                        "local", "udp", "local", "udp", 1000);
+const P2PTransportChannelTestBase::Result P2PTransportChannelTestBase::
+    kLocalUdpToStunUdp("local", "udp", "stun", "udp",
+                       "local", "udp", "stun", "udp", 1000);
+const P2PTransportChannelTestBase::Result P2PTransportChannelTestBase::
+    kLocalUdpToPrflxUdp("local", "udp", "prflx", "udp",
+                        "prflx", "udp", "local", "udp", 1000);
+const P2PTransportChannelTestBase::Result P2PTransportChannelTestBase::
+    kPrflxUdpToLocalUdp("prflx", "udp", "local", "udp",
+                        "local", "udp", "prflx", "udp", 1000);
+const P2PTransportChannelTestBase::Result P2PTransportChannelTestBase::
+    kStunUdpToLocalUdp("stun", "udp", "local", "udp",
+                       "local", "udp", "stun", "udp", 1000);
+const P2PTransportChannelTestBase::Result P2PTransportChannelTestBase::
+    kStunUdpToStunUdp("stun", "udp", "stun", "udp",
+                      "stun", "udp", "stun", "udp", 1000);
+const P2PTransportChannelTestBase::Result P2PTransportChannelTestBase::
+    kPrflxUdpToStunUdp("prflx", "udp", "stun", "udp",
+                       "local", "udp", "prflx", "udp", 1000);
+const P2PTransportChannelTestBase::Result P2PTransportChannelTestBase::
+    kLocalUdpToRelayUdp("local", "udp", "relay", "udp",
+                        "relay", "udp", "local", "udp", 2000);
+const P2PTransportChannelTestBase::Result P2PTransportChannelTestBase::
+    kPrflxUdpToRelayUdp("prflx", "udp", "relay", "udp",
+                        "relay", "udp", "prflx", "udp", 2000);
+const P2PTransportChannelTestBase::Result P2PTransportChannelTestBase::
+    kLocalTcpToLocalTcp("local", "tcp", "local", "tcp",
+                        "local", "tcp", "local", "tcp", 3000);
+const P2PTransportChannelTestBase::Result P2PTransportChannelTestBase::
+    kLocalTcpToPrflxTcp("local", "tcp", "prflx", "tcp",
+                        "prflx", "tcp", "local", "tcp", 3000);
+const P2PTransportChannelTestBase::Result P2PTransportChannelTestBase::
+    kPrflxTcpToLocalTcp("prflx", "tcp", "local", "tcp",
+                        "local", "tcp", "prflx", "tcp", 3000);
+
+// Test the matrix of all the connectivity types we expect to see in the wild.
+// Just test every combination of the configs in the Config enum.
+class P2PTransportChannelTest : public P2PTransportChannelTestBase {
+ protected:
+  static const Result* kMatrix[NUM_CONFIGS][NUM_CONFIGS];
+  static const Result* kMatrixSharedUfrag[NUM_CONFIGS][NUM_CONFIGS];
+  static const Result* kMatrixSharedSocketAsGice[NUM_CONFIGS][NUM_CONFIGS];
+  static const Result* kMatrixSharedSocketAsIce[NUM_CONFIGS][NUM_CONFIGS];
+  void ConfigureEndpoints(Config config1, Config config2,
+      int allocator_flags1, int allocator_flags2,
+      int delay1, int delay2,
+      cricket::IceProtocolType type) {
+    // Ideally we want to use TURN server for both GICE and ICE, but in case
+    // of GICE, TURN server usage is not producing results reliabally.
+    // TODO(mallinath): Remove Relay and use TURN server for all tests.
+    ServerAddresses stun_servers;
+    stun_servers.insert(kStunAddr);
+    GetEndpoint(0)->allocator_.reset(
+        new cricket::BasicPortAllocator(&(GetEndpoint(0)->network_manager_),
+        stun_servers,
+        rtc::SocketAddress(), rtc::SocketAddress(),
+        rtc::SocketAddress()));
+    GetEndpoint(1)->allocator_.reset(
+        new cricket::BasicPortAllocator(&(GetEndpoint(1)->network_manager_),
+        stun_servers,
+        rtc::SocketAddress(), rtc::SocketAddress(),
+        rtc::SocketAddress()));
+
+    cricket::RelayServerConfig relay_server(cricket::RELAY_GTURN);
+    if (type == cricket::ICEPROTO_RFC5245) {
+      relay_server.type = cricket::RELAY_TURN;
+      relay_server.credentials = kRelayCredentials;
+      relay_server.ports.push_back(cricket::ProtocolAddress(
+          kTurnUdpIntAddr, cricket::PROTO_UDP, false));
+    } else {
+      relay_server.ports.push_back(cricket::ProtocolAddress(
+          kRelayUdpIntAddr, cricket::PROTO_UDP, false));
+      relay_server.ports.push_back(cricket::ProtocolAddress(
+          kRelayTcpIntAddr, cricket::PROTO_TCP, false));
+      relay_server.ports.push_back(cricket::ProtocolAddress(
+          kRelaySslTcpIntAddr, cricket::PROTO_SSLTCP, false));
+    }
+    GetEndpoint(0)->allocator_->AddRelay(relay_server);
+    GetEndpoint(1)->allocator_->AddRelay(relay_server);
+
+    ConfigureEndpoint(0, config1);
+    SetIceProtocol(0, type);
+    SetAllocatorFlags(0, allocator_flags1);
+    SetAllocationStepDelay(0, delay1);
+    ConfigureEndpoint(1, config2);
+    SetIceProtocol(1, type);
+    SetAllocatorFlags(1, allocator_flags2);
+    SetAllocationStepDelay(1, delay2);
+  }
+  void ConfigureEndpoint(int endpoint, Config config) {
+    switch (config) {
+      case OPEN:
+        AddAddress(endpoint, kPublicAddrs[endpoint]);
+        break;
+      case NAT_FULL_CONE:
+      case NAT_ADDR_RESTRICTED:
+      case NAT_PORT_RESTRICTED:
+      case NAT_SYMMETRIC:
+        AddAddress(endpoint, kPrivateAddrs[endpoint]);
+        // Add a single NAT of the desired type
+        nat()->AddTranslator(kPublicAddrs[endpoint], kNatAddrs[endpoint],
+            static_cast<rtc::NATType>(config - NAT_FULL_CONE))->
+            AddClient(kPrivateAddrs[endpoint]);
+        break;
+      case NAT_DOUBLE_CONE:
+      case NAT_SYMMETRIC_THEN_CONE:
+        AddAddress(endpoint, kCascadedPrivateAddrs[endpoint]);
+        // Add a two cascaded NATs of the desired types
+        nat()->AddTranslator(kPublicAddrs[endpoint], kNatAddrs[endpoint],
+            (config == NAT_DOUBLE_CONE) ?
+                rtc::NAT_OPEN_CONE : rtc::NAT_SYMMETRIC)->
+            AddTranslator(kPrivateAddrs[endpoint], kCascadedNatAddrs[endpoint],
+                rtc::NAT_OPEN_CONE)->
+                AddClient(kCascadedPrivateAddrs[endpoint]);
+        break;
+      case BLOCK_UDP:
+      case BLOCK_UDP_AND_INCOMING_TCP:
+      case BLOCK_ALL_BUT_OUTGOING_HTTP:
+      case PROXY_HTTPS:
+      case PROXY_SOCKS:
+        AddAddress(endpoint, kPublicAddrs[endpoint]);
+        // Block all UDP
+        fw()->AddRule(false, rtc::FP_UDP, rtc::FD_ANY,
+                      kPublicAddrs[endpoint]);
+        if (config == BLOCK_UDP_AND_INCOMING_TCP) {
+          // Block TCP inbound to the endpoint
+          fw()->AddRule(false, rtc::FP_TCP, SocketAddress(),
+                        kPublicAddrs[endpoint]);
+        } else if (config == BLOCK_ALL_BUT_OUTGOING_HTTP) {
+          // Block all TCP to/from the endpoint except 80/443 out
+          fw()->AddRule(true, rtc::FP_TCP, kPublicAddrs[endpoint],
+                        SocketAddress(rtc::IPAddress(INADDR_ANY), 80));
+          fw()->AddRule(true, rtc::FP_TCP, kPublicAddrs[endpoint],
+                        SocketAddress(rtc::IPAddress(INADDR_ANY), 443));
+          fw()->AddRule(false, rtc::FP_TCP, rtc::FD_ANY,
+                        kPublicAddrs[endpoint]);
+        } else if (config == PROXY_HTTPS) {
+          // Block all TCP to/from the endpoint except to the proxy server
+          fw()->AddRule(true, rtc::FP_TCP, kPublicAddrs[endpoint],
+                        kHttpsProxyAddrs[endpoint]);
+          fw()->AddRule(false, rtc::FP_TCP, rtc::FD_ANY,
+                        kPublicAddrs[endpoint]);
+          SetProxy(endpoint, rtc::PROXY_HTTPS);
+        } else if (config == PROXY_SOCKS) {
+          // Block all TCP to/from the endpoint except to the proxy server
+          fw()->AddRule(true, rtc::FP_TCP, kPublicAddrs[endpoint],
+                        kSocksProxyAddrs[endpoint]);
+          fw()->AddRule(false, rtc::FP_TCP, rtc::FD_ANY,
+                        kPublicAddrs[endpoint]);
+          SetProxy(endpoint, rtc::PROXY_SOCKS5);
+        }
+        break;
+      default:
+        break;
+    }
+  }
+};
+
+// Shorthands for use in the test matrix.
+#define LULU &kLocalUdpToLocalUdp
+#define LUSU &kLocalUdpToStunUdp
+#define LUPU &kLocalUdpToPrflxUdp
+#define PULU &kPrflxUdpToLocalUdp
+#define SULU &kStunUdpToLocalUdp
+#define SUSU &kStunUdpToStunUdp
+#define PUSU &kPrflxUdpToStunUdp
+#define LURU &kLocalUdpToRelayUdp
+#define PURU &kPrflxUdpToRelayUdp
+#define LTLT &kLocalTcpToLocalTcp
+#define LTPT &kLocalTcpToPrflxTcp
+#define PTLT &kPrflxTcpToLocalTcp
+// TODO: Enable these once TestRelayServer can accept external TCP.
+#define LTRT NULL
+#define LSRS NULL
+
+// Test matrix. Originator behavior defined by rows, receiever by columns.
+
+// Currently the p2ptransportchannel.cc (specifically the
+// P2PTransportChannel::OnUnknownAddress) operates in 2 modes depend on the
+// remote candidates - ufrag per port or shared ufrag.
+// For example, if the remote candidates have the shared ufrag, for the unknown
+// address reaches the OnUnknownAddress, we will try to find the matched
+// remote candidate based on the address and protocol, if not found, a new
+// remote candidate will be created for this address. But if the remote
+// candidates have different ufrags, we will try to find the matched remote
+// candidate by comparing the ufrag. If not found, an error will be returned.
+// Because currently the shared ufrag feature is under the experiment and will
+// be rolled out gradually. We want to test the different combinations of peers
+// with/without the shared ufrag enabled. And those different combinations have
+// different expectation of the best connection. For example in the OpenToCONE
+// case, an unknown address will be updated to a "host" remote candidate if the
+// remote peer uses different ufrag per port. But in the shared ufrag case,
+// a "stun" (should be peer-reflexive eventually) candidate will be created for
+// that. So the expected best candidate will be LUSU instead of LULU.
+// With all these, we have to keep 2 test matrixes for the tests:
+// kMatrix - for the tests that the remote peer uses different ufrag per port.
+// kMatrixSharedUfrag - for the tests that remote peer uses shared ufrag.
+// The different between the two matrixes are on:
+// OPToCONE, OPTo2CON,
+// COToCONE, COToADDR, COToPORT, COToSYMM, COTo2CON, COToSCON,
+// ADToCONE, ADToADDR, ADTo2CON,
+// POToADDR,
+// SYToADDR,
+// 2CToCONE, 2CToADDR, 2CToPORT, 2CToSYMM, 2CTo2CON, 2CToSCON,
+// SCToADDR,
+
+// TODO: Fix NULLs caused by lack of TCP support in NATSocket.
+// TODO: Fix NULLs caused by no HTTP proxy support.
+// TODO: Rearrange rows/columns from best to worst.
+// TODO(ronghuawu): Keep only one test matrix once the shared ufrag is enabled.
+const P2PTransportChannelTest::Result*
+    P2PTransportChannelTest::kMatrix[NUM_CONFIGS][NUM_CONFIGS] = {
+//      OPEN  CONE  ADDR  PORT  SYMM  2CON  SCON  !UDP  !TCP  HTTP  PRXH  PRXS
+/*OP*/ {LULU, LULU, LULU, LULU, LULU, LULU, LULU, LTLT, LTLT, LSRS, NULL, LTLT},
+/*CO*/ {LULU, LULU, LULU, SULU, SULU, LULU, SULU, NULL, NULL, LSRS, NULL, LTRT},
+/*AD*/ {LULU, LULU, LULU, SUSU, SUSU, LULU, SUSU, NULL, NULL, LSRS, NULL, LTRT},
+/*PO*/ {LULU, LUSU, LUSU, SUSU, LURU, LUSU, LURU, NULL, NULL, LSRS, NULL, LTRT},
+/*SY*/ {LULU, LUSU, LUSU, LURU, LURU, LUSU, LURU, NULL, NULL, LSRS, NULL, LTRT},
+/*2C*/ {LULU, LULU, LULU, SULU, SULU, LULU, SULU, NULL, NULL, LSRS, NULL, LTRT},
+/*SC*/ {LULU, LUSU, LUSU, LURU, LURU, LUSU, LURU, NULL, NULL, LSRS, NULL, LTRT},
+/*!U*/ {LTLT, NULL, NULL, NULL, NULL, NULL, NULL, LTLT, LTLT, LSRS, NULL, LTRT},
+/*!T*/ {LTRT, NULL, NULL, NULL, NULL, NULL, NULL, LTLT, LTRT, LSRS, NULL, LTRT},
+/*HT*/ {LSRS, LSRS, LSRS, LSRS, LSRS, LSRS, LSRS, LSRS, LSRS, LSRS, NULL, LSRS},
+/*PR*/ {NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
+/*PR*/ {LTRT, LTRT, LTRT, LTRT, LTRT, LTRT, LTRT, LTRT, LTRT, LSRS, NULL, LTRT},
+};
+const P2PTransportChannelTest::Result*
+    P2PTransportChannelTest::kMatrixSharedUfrag[NUM_CONFIGS][NUM_CONFIGS] = {
+//      OPEN  CONE  ADDR  PORT  SYMM  2CON  SCON  !UDP  !TCP  HTTP  PRXH  PRXS
+/*OP*/ {LULU, LUSU, LULU, LULU, LULU, LUSU, LULU, LTLT, LTLT, LSRS, NULL, LTLT},
+/*CO*/ {LULU, LUSU, LUSU, SUSU, SUSU, LUSU, SUSU, NULL, NULL, LSRS, NULL, LTRT},
+/*AD*/ {LULU, LUSU, LUSU, SUSU, SUSU, LUSU, SUSU, NULL, NULL, LSRS, NULL, LTRT},
+/*PO*/ {LULU, LUSU, LUSU, SUSU, LURU, LUSU, LURU, NULL, NULL, LSRS, NULL, LTRT},
+/*SY*/ {LULU, LUSU, LUSU, LURU, LURU, LUSU, LURU, NULL, NULL, LSRS, NULL, LTRT},
+/*2C*/ {LULU, LUSU, LUSU, SUSU, SUSU, LUSU, SUSU, NULL, NULL, LSRS, NULL, LTRT},
+/*SC*/ {LULU, LUSU, LUSU, LURU, LURU, LUSU, LURU, NULL, NULL, LSRS, NULL, LTRT},
+/*!U*/ {LTLT, NULL, NULL, NULL, NULL, NULL, NULL, LTLT, LTLT, LSRS, NULL, LTRT},
+/*!T*/ {LTRT, NULL, NULL, NULL, NULL, NULL, NULL, LTLT, LTRT, LSRS, NULL, LTRT},
+/*HT*/ {LSRS, LSRS, LSRS, LSRS, LSRS, LSRS, LSRS, LSRS, LSRS, LSRS, NULL, LSRS},
+/*PR*/ {NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
+/*PR*/ {LTRT, LTRT, LTRT, LTRT, LTRT, LTRT, LTRT, LTRT, LTRT, LSRS, NULL, LTRT},
+};
+const P2PTransportChannelTest::Result*
+    P2PTransportChannelTest::kMatrixSharedSocketAsGice
+        [NUM_CONFIGS][NUM_CONFIGS] = {
+//      OPEN  CONE  ADDR  PORT  SYMM  2CON  SCON  !UDP  !TCP  HTTP  PRXH  PRXS
+/*OP*/ {LULU, LUSU, LUSU, LUSU, LUSU, LUSU, LUSU, LTLT, LTLT, LSRS, NULL, LTLT},
+/*CO*/ {LULU, LUSU, LUSU, LUSU, LUSU, LUSU, LUSU, NULL, NULL, LSRS, NULL, LTRT},
+/*AD*/ {LULU, LUSU, LUSU, LUSU, LUSU, LUSU, LUSU, NULL, NULL, LSRS, NULL, LTRT},
+/*PO*/ {LULU, LUSU, LUSU, LUSU, LURU, LUSU, LURU, NULL, NULL, LSRS, NULL, LTRT},
+/*SY*/ {LULU, LUSU, LUSU, LURU, LURU, LUSU, LURU, NULL, NULL, LSRS, NULL, LTRT},
+/*2C*/ {LULU, LUSU, LUSU, LUSU, LUSU, LUSU, LUSU, NULL, NULL, LSRS, NULL, LTRT},
+/*SC*/ {LULU, LUSU, LUSU, LURU, LURU, LUSU, LURU, NULL, NULL, LSRS, NULL, LTRT},
+/*!U*/ {LTLT, NULL, NULL, NULL, NULL, NULL, NULL, LTLT, LTLT, LSRS, NULL, LTRT},
+/*!T*/ {LTRT, NULL, NULL, NULL, NULL, NULL, NULL, LTLT, LTRT, LSRS, NULL, LTRT},
+/*HT*/ {LSRS, LSRS, LSRS, LSRS, LSRS, LSRS, LSRS, LSRS, LSRS, LSRS, NULL, LSRS},
+/*PR*/ {NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
+/*PR*/ {LTRT, LTRT, LTRT, LTRT, LTRT, LTRT, LTRT, LTRT, LTRT, LSRS, NULL, LTRT},
+};
+const P2PTransportChannelTest::Result*
+    P2PTransportChannelTest::kMatrixSharedSocketAsIce
+        [NUM_CONFIGS][NUM_CONFIGS] = {
+//      OPEN  CONE  ADDR  PORT  SYMM  2CON  SCON  !UDP  !TCP  HTTP  PRXH  PRXS
+/*OP*/ {LULU, LUSU, LUSU, LUSU, LUPU, LUSU, LUPU, PTLT, LTPT, LSRS, NULL, PTLT},
+/*CO*/ {LULU, LUSU, LUSU, LUSU, LUPU, LUSU, LUPU, NULL, NULL, LSRS, NULL, LTRT},
+/*AD*/ {LULU, LUSU, LUSU, LUSU, LUPU, LUSU, LUPU, NULL, NULL, LSRS, NULL, LTRT},
+/*PO*/ {LULU, LUSU, LUSU, LUSU, LURU, LUSU, LURU, NULL, NULL, LSRS, NULL, LTRT},
+/*SY*/ {PULU, PUSU, PUSU, PURU, PURU, PUSU, PURU, NULL, NULL, LSRS, NULL, LTRT},
+/*2C*/ {LULU, LUSU, LUSU, LUSU, LUPU, LUSU, LUPU, NULL, NULL, LSRS, NULL, LTRT},
+/*SC*/ {PULU, PUSU, PUSU, PURU, PURU, PUSU, PURU, NULL, NULL, LSRS, NULL, LTRT},
+/*!U*/ {PTLT, NULL, NULL, NULL, NULL, NULL, NULL, PTLT, LTPT, LSRS, NULL, LTRT},
+/*!T*/ {LTRT, NULL, NULL, NULL, NULL, NULL, NULL, PTLT, LTRT, LSRS, NULL, LTRT},
+/*HT*/ {LSRS, LSRS, LSRS, LSRS, LSRS, LSRS, LSRS, LSRS, LSRS, LSRS, NULL, LSRS},
+/*PR*/ {NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL},
+/*PR*/ {LTRT, LTRT, LTRT, LTRT, LTRT, LTRT, LTRT, LTRT, LTRT, LSRS, NULL, LTRT},
+};
+
+// The actual tests that exercise all the various configurations.
+// Test names are of the form P2PTransportChannelTest_TestOPENToNAT_FULL_CONE
+// Same test case is run in both GICE and ICE mode.
+// kDefaultStepDelay - is used for all Gice cases.
+// kMinimumStepDelay - is used when both end points have
+//                     PORTALLOCATOR_ENABLE_SHARED_UFRAG flag enabled.
+// Technically we should be able to use kMinimumStepDelay irrespective of
+// protocol type. But which might need modifications to current result matrices
+// for tests in this file.
+#define P2P_TEST_DECLARATION(x, y, z) \
+  TEST_F(P2PTransportChannelTest, z##Test##x##To##y##AsGiceNoneSharedUfrag) { \
+    ConfigureEndpoints(x, y, kDefaultPortAllocatorFlags, \
+                       kDefaultPortAllocatorFlags, \
+                       kDefaultStepDelay, kDefaultStepDelay, \
+                       cricket::ICEPROTO_GOOGLE); \
+    if (kMatrix[x][y] != NULL) \
+      Test(*kMatrix[x][y]); \
+    else \
+      LOG(LS_WARNING) << "Not yet implemented"; \
+  } \
+  TEST_F(P2PTransportChannelTest, z##Test##x##To##y##AsGiceP0SharedUfrag) { \
+    ConfigureEndpoints(x, y, PORTALLOCATOR_ENABLE_SHARED_UFRAG, \
+                       kDefaultPortAllocatorFlags, \
+                       kDefaultStepDelay, kDefaultStepDelay, \
+                       cricket::ICEPROTO_GOOGLE); \
+    if (kMatrix[x][y] != NULL) \
+      Test(*kMatrix[x][y]); \
+    else \
+      LOG(LS_WARNING) << "Not yet implemented"; \
+  } \
+  TEST_F(P2PTransportChannelTest, z##Test##x##To##y##AsGiceP1SharedUfrag) { \
+    ConfigureEndpoints(x, y, kDefaultPortAllocatorFlags, \
+                       PORTALLOCATOR_ENABLE_SHARED_UFRAG, \
+                       kDefaultStepDelay, kDefaultStepDelay, \
+                       cricket::ICEPROTO_GOOGLE); \
+    if (kMatrixSharedUfrag[x][y] != NULL) \
+      Test(*kMatrixSharedUfrag[x][y]); \
+    else \
+      LOG(LS_WARNING) << "Not yet implemented"; \
+  } \
+  TEST_F(P2PTransportChannelTest, z##Test##x##To##y##AsGiceBothSharedUfrag) { \
+    ConfigureEndpoints(x, y, PORTALLOCATOR_ENABLE_SHARED_UFRAG, \
+                       PORTALLOCATOR_ENABLE_SHARED_UFRAG, \
+                       kDefaultStepDelay, kDefaultStepDelay, \
+                       cricket::ICEPROTO_GOOGLE); \
+    if (kMatrixSharedUfrag[x][y] != NULL) \
+      Test(*kMatrixSharedUfrag[x][y]); \
+    else \
+      LOG(LS_WARNING) << "Not yet implemented"; \
+  } \
+  TEST_F(P2PTransportChannelTest, \
+         z##Test##x##To##y##AsGiceBothSharedUfragWithMinimumStepDelay) { \
+    ConfigureEndpoints(x, y, PORTALLOCATOR_ENABLE_SHARED_UFRAG, \
+                       PORTALLOCATOR_ENABLE_SHARED_UFRAG, \
+                       kMinimumStepDelay, kMinimumStepDelay, \
+                       cricket::ICEPROTO_GOOGLE); \
+    if (kMatrixSharedUfrag[x][y] != NULL) \
+      Test(*kMatrixSharedUfrag[x][y]); \
+    else \
+      LOG(LS_WARNING) << "Not yet implemented"; \
+  } \
+  TEST_F(P2PTransportChannelTest, \
+         z##Test##x##To##y##AsGiceBothSharedUfragSocket) { \
+    ConfigureEndpoints(x, y, PORTALLOCATOR_ENABLE_SHARED_UFRAG | \
+                       PORTALLOCATOR_ENABLE_SHARED_SOCKET, \
+                       PORTALLOCATOR_ENABLE_SHARED_UFRAG | \
+                       PORTALLOCATOR_ENABLE_SHARED_SOCKET, \
+                       kMinimumStepDelay, kMinimumStepDelay, \
+                       cricket::ICEPROTO_GOOGLE); \
+    if (kMatrixSharedSocketAsGice[x][y] != NULL) \
+      Test(*kMatrixSharedSocketAsGice[x][y]); \
+    else \
+    LOG(LS_WARNING) << "Not yet implemented"; \
+  } \
+  TEST_F(P2PTransportChannelTest, z##Test##x##To##y##AsIce) { \
+    ConfigureEndpoints(x, y, PORTALLOCATOR_ENABLE_SHARED_UFRAG | \
+                       PORTALLOCATOR_ENABLE_SHARED_SOCKET, \
+                       PORTALLOCATOR_ENABLE_SHARED_UFRAG | \
+                       PORTALLOCATOR_ENABLE_SHARED_SOCKET, \
+                       kMinimumStepDelay, kMinimumStepDelay, \
+                       cricket::ICEPROTO_RFC5245); \
+    if (kMatrixSharedSocketAsIce[x][y] != NULL) \
+      Test(*kMatrixSharedSocketAsIce[x][y]); \
+    else \
+    LOG(LS_WARNING) << "Not yet implemented"; \
+  }
+
+#define P2P_TEST(x, y) \
+  P2P_TEST_DECLARATION(x, y,)
+
+#define FLAKY_P2P_TEST(x, y) \
+  P2P_TEST_DECLARATION(x, y, DISABLED_)
+
+// TODO(holmer): Disabled due to randomly failing on webrtc buildbots.
+// Issue: webrtc/2383
+#define P2P_TEST_SET(x) \
+  P2P_TEST(x, OPEN) \
+  FLAKY_P2P_TEST(x, NAT_FULL_CONE) \
+  FLAKY_P2P_TEST(x, NAT_ADDR_RESTRICTED) \
+  FLAKY_P2P_TEST(x, NAT_PORT_RESTRICTED) \
+  P2P_TEST(x, NAT_SYMMETRIC) \
+  FLAKY_P2P_TEST(x, NAT_DOUBLE_CONE) \
+  P2P_TEST(x, NAT_SYMMETRIC_THEN_CONE) \
+  P2P_TEST(x, BLOCK_UDP) \
+  P2P_TEST(x, BLOCK_UDP_AND_INCOMING_TCP) \
+  P2P_TEST(x, BLOCK_ALL_BUT_OUTGOING_HTTP) \
+  P2P_TEST(x, PROXY_HTTPS) \
+  P2P_TEST(x, PROXY_SOCKS)
+
+#define FLAKY_P2P_TEST_SET(x) \
+  P2P_TEST(x, OPEN) \
+  P2P_TEST(x, NAT_FULL_CONE) \
+  P2P_TEST(x, NAT_ADDR_RESTRICTED) \
+  P2P_TEST(x, NAT_PORT_RESTRICTED) \
+  P2P_TEST(x, NAT_SYMMETRIC) \
+  P2P_TEST(x, NAT_DOUBLE_CONE) \
+  P2P_TEST(x, NAT_SYMMETRIC_THEN_CONE) \
+  P2P_TEST(x, BLOCK_UDP) \
+  P2P_TEST(x, BLOCK_UDP_AND_INCOMING_TCP) \
+  P2P_TEST(x, BLOCK_ALL_BUT_OUTGOING_HTTP) \
+  P2P_TEST(x, PROXY_HTTPS) \
+  P2P_TEST(x, PROXY_SOCKS)
+
+P2P_TEST_SET(OPEN)
+P2P_TEST_SET(NAT_FULL_CONE)
+P2P_TEST_SET(NAT_ADDR_RESTRICTED)
+P2P_TEST_SET(NAT_PORT_RESTRICTED)
+P2P_TEST_SET(NAT_SYMMETRIC)
+P2P_TEST_SET(NAT_DOUBLE_CONE)
+P2P_TEST_SET(NAT_SYMMETRIC_THEN_CONE)
+P2P_TEST_SET(BLOCK_UDP)
+P2P_TEST_SET(BLOCK_UDP_AND_INCOMING_TCP)
+P2P_TEST_SET(BLOCK_ALL_BUT_OUTGOING_HTTP)
+P2P_TEST_SET(PROXY_HTTPS)
+P2P_TEST_SET(PROXY_SOCKS)
+
+// Test that we restart candidate allocation when local ufrag&pwd changed.
+// Standard Ice protocol is used.
+TEST_F(P2PTransportChannelTest, HandleUfragPwdChangeAsIce) {
+  ConfigureEndpoints(OPEN, OPEN,
+                     PORTALLOCATOR_ENABLE_SHARED_UFRAG,
+                     PORTALLOCATOR_ENABLE_SHARED_UFRAG,
+                     kMinimumStepDelay, kMinimumStepDelay,
+                     cricket::ICEPROTO_RFC5245);
+  CreateChannels(1);
+  TestHandleIceUfragPasswordChanged();
+  DestroyChannels();
+}
+
+// Test that we restart candidate allocation when local ufrag&pwd changed.
+// Standard Ice protocol is used.
+TEST_F(P2PTransportChannelTest, HandleUfragPwdChangeBundleAsIce) {
+  ConfigureEndpoints(OPEN, OPEN,
+                     PORTALLOCATOR_ENABLE_SHARED_UFRAG,
+                     PORTALLOCATOR_ENABLE_SHARED_UFRAG,
+                     kMinimumStepDelay, kMinimumStepDelay,
+                     cricket::ICEPROTO_RFC5245);
+  SetAllocatorFlags(0, cricket::PORTALLOCATOR_ENABLE_BUNDLE);
+  SetAllocatorFlags(1, cricket::PORTALLOCATOR_ENABLE_BUNDLE);
+
+  CreateChannels(2);
+  TestHandleIceUfragPasswordChanged();
+  DestroyChannels();
+}
+
+// Test that we restart candidate allocation when local ufrag&pwd changed.
+// Google Ice protocol is used.
+TEST_F(P2PTransportChannelTest, HandleUfragPwdChangeAsGice) {
+  ConfigureEndpoints(OPEN, OPEN,
+                     PORTALLOCATOR_ENABLE_SHARED_UFRAG,
+                     PORTALLOCATOR_ENABLE_SHARED_UFRAG,
+                     kDefaultStepDelay, kDefaultStepDelay,
+                     cricket::ICEPROTO_GOOGLE);
+  CreateChannels(1);
+  TestHandleIceUfragPasswordChanged();
+  DestroyChannels();
+}
+
+// Test that ICE restart works when bundle is enabled.
+// Google Ice protocol is used.
+TEST_F(P2PTransportChannelTest, HandleUfragPwdChangeBundleAsGice) {
+  ConfigureEndpoints(OPEN, OPEN,
+                     PORTALLOCATOR_ENABLE_SHARED_UFRAG,
+                     PORTALLOCATOR_ENABLE_SHARED_UFRAG,
+                     kDefaultStepDelay, kDefaultStepDelay,
+                     cricket::ICEPROTO_GOOGLE);
+  SetAllocatorFlags(0, cricket::PORTALLOCATOR_ENABLE_BUNDLE);
+  SetAllocatorFlags(1, cricket::PORTALLOCATOR_ENABLE_BUNDLE);
+
+  CreateChannels(2);
+  TestHandleIceUfragPasswordChanged();
+  DestroyChannels();
+}
+
+// Test the operation of GetStats.
+TEST_F(P2PTransportChannelTest, GetStats) {
+  ConfigureEndpoints(OPEN, OPEN,
+                     kDefaultPortAllocatorFlags,
+                     kDefaultPortAllocatorFlags,
+                     kDefaultStepDelay, kDefaultStepDelay,
+                     cricket::ICEPROTO_GOOGLE);
+  CreateChannels(1);
+  EXPECT_TRUE_WAIT_MARGIN(ep1_ch1()->readable() && ep1_ch1()->writable() &&
+                          ep2_ch1()->readable() && ep2_ch1()->writable(),
+                          1000, 1000);
+  TestSendRecv(1);
+  cricket::ConnectionInfos infos;
+  ASSERT_TRUE(ep1_ch1()->GetStats(&infos));
+  ASSERT_EQ(1U, infos.size());
+  EXPECT_TRUE(infos[0].new_connection);
+  EXPECT_TRUE(infos[0].best_connection);
+  EXPECT_TRUE(infos[0].readable);
+  EXPECT_TRUE(infos[0].writable);
+  EXPECT_FALSE(infos[0].timeout);
+  EXPECT_EQ(10 * 36U, infos[0].sent_total_bytes);
+  EXPECT_EQ(10 * 36U, infos[0].recv_total_bytes);
+  EXPECT_GT(infos[0].rtt, 0U);
+  DestroyChannels();
+}
+
+// Test that we properly handle getting a STUN error due to slow signaling.
+TEST_F(P2PTransportChannelTest, DISABLED_SlowSignaling) {
+  ConfigureEndpoints(OPEN, NAT_SYMMETRIC,
+                     kDefaultPortAllocatorFlags,
+                     kDefaultPortAllocatorFlags,
+                     kDefaultStepDelay, kDefaultStepDelay,
+                     cricket::ICEPROTO_GOOGLE);
+  // Make signaling from the callee take 500ms, so that the initial STUN pings
+  // from the callee beat the signaling, and so the caller responds with a
+  // unknown username error. We should just eat that and carry on; mishandling
+  // this will instead cause all the callee's connections to be discarded.
+  SetSignalingDelay(1, 1000);
+  CreateChannels(1);
+  const cricket::Connection* best_connection = NULL;
+  // Wait until the callee's connections are created.
+  WAIT((best_connection = ep2_ch1()->best_connection()) != NULL, 1000);
+  // Wait to see if they get culled; they shouldn't.
+  WAIT(ep2_ch1()->best_connection() != best_connection, 1000);
+  EXPECT_TRUE(ep2_ch1()->best_connection() == best_connection);
+  DestroyChannels();
+}
+
+// Test that if remote candidates don't have ufrag and pwd, we still work.
+TEST_F(P2PTransportChannelTest, RemoteCandidatesWithoutUfragPwd) {
+  set_clear_remote_candidates_ufrag_pwd(true);
+  ConfigureEndpoints(OPEN, OPEN,
+                     PORTALLOCATOR_ENABLE_SHARED_UFRAG,
+                     PORTALLOCATOR_ENABLE_SHARED_UFRAG,
+                     kMinimumStepDelay, kMinimumStepDelay,
+                     cricket::ICEPROTO_GOOGLE);
+  CreateChannels(1);
+  const cricket::Connection* best_connection = NULL;
+  // Wait until the callee's connections are created.
+  WAIT((best_connection = ep2_ch1()->best_connection()) != NULL, 1000);
+  // Wait to see if they get culled; they shouldn't.
+  WAIT(ep2_ch1()->best_connection() != best_connection, 1000);
+  EXPECT_TRUE(ep2_ch1()->best_connection() == best_connection);
+  DestroyChannels();
+}
+
+// Test that a host behind NAT cannot be reached when incoming_only
+// is set to true.
+TEST_F(P2PTransportChannelTest, IncomingOnlyBlocked) {
+  ConfigureEndpoints(NAT_FULL_CONE, OPEN,
+                     kDefaultPortAllocatorFlags,
+                     kDefaultPortAllocatorFlags,
+                     kDefaultStepDelay, kDefaultStepDelay,
+                     cricket::ICEPROTO_GOOGLE);
+
+  SetAllocatorFlags(0, kOnlyLocalPorts);
+  CreateChannels(1);
+  ep1_ch1()->set_incoming_only(true);
+
+  // Pump for 1 second and verify that the channels are not connected.
+  rtc::Thread::Current()->ProcessMessages(1000);
+
+  EXPECT_FALSE(ep1_ch1()->readable());
+  EXPECT_FALSE(ep1_ch1()->writable());
+  EXPECT_FALSE(ep2_ch1()->readable());
+  EXPECT_FALSE(ep2_ch1()->writable());
+
+  DestroyChannels();
+}
+
+// Test that a peer behind NAT can connect to a peer that has
+// incoming_only flag set.
+TEST_F(P2PTransportChannelTest, IncomingOnlyOpen) {
+  ConfigureEndpoints(OPEN, NAT_FULL_CONE,
+                     kDefaultPortAllocatorFlags,
+                     kDefaultPortAllocatorFlags,
+                     kDefaultStepDelay, kDefaultStepDelay,
+                     cricket::ICEPROTO_GOOGLE);
+
+  SetAllocatorFlags(0, kOnlyLocalPorts);
+  CreateChannels(1);
+  ep1_ch1()->set_incoming_only(true);
+
+  EXPECT_TRUE_WAIT_MARGIN(ep1_ch1() != NULL && ep2_ch1() != NULL &&
+                          ep1_ch1()->readable() && ep1_ch1()->writable() &&
+                          ep2_ch1()->readable() && ep2_ch1()->writable(),
+                          1000, 1000);
+
+  DestroyChannels();
+}
+
+TEST_F(P2PTransportChannelTest, TestTcpConnectionsFromActiveToPassive) {
+  AddAddress(0, kPublicAddrs[0]);
+  AddAddress(1, kPublicAddrs[1]);
+
+  SetAllocationStepDelay(0, kMinimumStepDelay);
+  SetAllocationStepDelay(1, kMinimumStepDelay);
+
+  int kOnlyLocalTcpPorts = cricket::PORTALLOCATOR_DISABLE_UDP |
+                           cricket::PORTALLOCATOR_DISABLE_STUN |
+                           cricket::PORTALLOCATOR_DISABLE_RELAY |
+                           cricket::PORTALLOCATOR_ENABLE_SHARED_UFRAG;
+  // Disable all protocols except TCP.
+  SetAllocatorFlags(0, kOnlyLocalTcpPorts);
+  SetAllocatorFlags(1, kOnlyLocalTcpPorts);
+
+  SetAllowTcpListen(0, true);   // actpass.
+  SetAllowTcpListen(1, false);  // active.
+
+  CreateChannels(1);
+
+  EXPECT_TRUE_WAIT(ep1_ch1()->readable() && ep1_ch1()->writable() &&
+                   ep2_ch1()->readable() && ep2_ch1()->writable(),
+                   1000);
+  EXPECT_TRUE(
+      ep1_ch1()->best_connection() && ep2_ch1()->best_connection() &&
+      LocalCandidate(ep1_ch1())->address().EqualIPs(kPublicAddrs[0]) &&
+      RemoteCandidate(ep1_ch1())->address().EqualIPs(kPublicAddrs[1]));
+
+  std::string kTcpProtocol = "tcp";
+  EXPECT_EQ(kTcpProtocol, RemoteCandidate(ep1_ch1())->protocol());
+  EXPECT_EQ(kTcpProtocol, LocalCandidate(ep1_ch1())->protocol());
+  EXPECT_EQ(kTcpProtocol, RemoteCandidate(ep2_ch1())->protocol());
+  EXPECT_EQ(kTcpProtocol, LocalCandidate(ep2_ch1())->protocol());
+
+  TestSendRecv(1);
+  DestroyChannels();
+}
+
+TEST_F(P2PTransportChannelTest, TestBundleAllocatorToBundleAllocator) {
+  AddAddress(0, kPublicAddrs[0]);
+  AddAddress(1, kPublicAddrs[1]);
+  SetAllocatorFlags(0, cricket::PORTALLOCATOR_ENABLE_BUNDLE);
+  SetAllocatorFlags(1, cricket::PORTALLOCATOR_ENABLE_BUNDLE);
+
+  CreateChannels(2);
+
+  EXPECT_TRUE_WAIT(ep1_ch1()->readable() &&
+                   ep1_ch1()->writable() &&
+                   ep2_ch1()->readable() &&
+                   ep2_ch1()->writable(),
+                   1000);
+  EXPECT_TRUE(ep1_ch1()->best_connection() &&
+              ep2_ch1()->best_connection());
+
+  EXPECT_FALSE(ep1_ch2()->readable());
+  EXPECT_FALSE(ep1_ch2()->writable());
+  EXPECT_FALSE(ep2_ch2()->readable());
+  EXPECT_FALSE(ep2_ch2()->writable());
+
+  TestSendRecv(1);  // Only 1 channel is writable per Endpoint.
+  DestroyChannels();
+}
+
+TEST_F(P2PTransportChannelTest, TestBundleAllocatorToNonBundleAllocator) {
+  AddAddress(0, kPublicAddrs[0]);
+  AddAddress(1, kPublicAddrs[1]);
+  // Enable BUNDLE flag at one side.
+  SetAllocatorFlags(0, cricket::PORTALLOCATOR_ENABLE_BUNDLE);
+
+  CreateChannels(2);
+
+  EXPECT_TRUE_WAIT(ep1_ch1()->readable() &&
+                   ep1_ch1()->writable() &&
+                   ep2_ch1()->readable() &&
+                   ep2_ch1()->writable(),
+                   1000);
+  EXPECT_TRUE_WAIT(ep1_ch2()->readable() &&
+                   ep1_ch2()->writable() &&
+                   ep2_ch2()->readable() &&
+                   ep2_ch2()->writable(),
+                   1000);
+
+  EXPECT_TRUE(ep1_ch1()->best_connection() &&
+              ep2_ch1()->best_connection());
+  EXPECT_TRUE(ep1_ch2()->best_connection() &&
+              ep2_ch2()->best_connection());
+
+  TestSendRecv(2);
+  DestroyChannels();
+}
+
+TEST_F(P2PTransportChannelTest, TestIceRoleConflictWithoutBundle) {
+  AddAddress(0, kPublicAddrs[0]);
+  AddAddress(1, kPublicAddrs[1]);
+  TestSignalRoleConflict();
+}
+
+TEST_F(P2PTransportChannelTest, TestIceRoleConflictWithBundle) {
+  AddAddress(0, kPublicAddrs[0]);
+  AddAddress(1, kPublicAddrs[1]);
+  SetAllocatorFlags(0, cricket::PORTALLOCATOR_ENABLE_BUNDLE);
+  SetAllocatorFlags(1, cricket::PORTALLOCATOR_ENABLE_BUNDLE);
+  TestSignalRoleConflict();
+}
+
+// Tests that the ice configs (protocol, tiebreaker and role) can be passed
+// down to ports.
+TEST_F(P2PTransportChannelTest, TestIceConfigWillPassDownToPort) {
+  AddAddress(0, kPublicAddrs[0]);
+  AddAddress(1, kPublicAddrs[1]);
+
+  SetIceRole(0, cricket::ICEROLE_CONTROLLING);
+  SetIceProtocol(0, cricket::ICEPROTO_GOOGLE);
+  SetIceTiebreaker(0, kTiebreaker1);
+  SetIceRole(1, cricket::ICEROLE_CONTROLLING);
+  SetIceProtocol(1, cricket::ICEPROTO_RFC5245);
+  SetIceTiebreaker(1, kTiebreaker2);
+
+  CreateChannels(1);
+
+  EXPECT_EQ_WAIT(2u, ep1_ch1()->ports().size(), 1000);
+
+  const std::vector<cricket::PortInterface *> ports_before = ep1_ch1()->ports();
+  for (size_t i = 0; i < ports_before.size(); ++i) {
+    EXPECT_EQ(cricket::ICEROLE_CONTROLLING, ports_before[i]->GetIceRole());
+    EXPECT_EQ(cricket::ICEPROTO_GOOGLE, ports_before[i]->IceProtocol());
+    EXPECT_EQ(kTiebreaker1, ports_before[i]->IceTiebreaker());
+  }
+
+  ep1_ch1()->SetIceRole(cricket::ICEROLE_CONTROLLED);
+  ep1_ch1()->SetIceProtocolType(cricket::ICEPROTO_RFC5245);
+  ep1_ch1()->SetIceTiebreaker(kTiebreaker2);
+
+  const std::vector<cricket::PortInterface *> ports_after = ep1_ch1()->ports();
+  for (size_t i = 0; i < ports_after.size(); ++i) {
+    EXPECT_EQ(cricket::ICEROLE_CONTROLLED, ports_before[i]->GetIceRole());
+    EXPECT_EQ(cricket::ICEPROTO_RFC5245, ports_before[i]->IceProtocol());
+    // SetIceTiebreaker after Connect() has been called will fail. So expect the
+    // original value.
+    EXPECT_EQ(kTiebreaker1, ports_before[i]->IceTiebreaker());
+  }
+
+  EXPECT_TRUE_WAIT(ep1_ch1()->readable() &&
+                   ep1_ch1()->writable() &&
+                   ep2_ch1()->readable() &&
+                   ep2_ch1()->writable(),
+                   1000);
+
+  EXPECT_TRUE(ep1_ch1()->best_connection() &&
+              ep2_ch1()->best_connection());
+
+  TestSendRecv(1);
+  DestroyChannels();
+}
+
+// This test verifies channel can handle ice messages when channel is in
+// hybrid mode.
+TEST_F(P2PTransportChannelTest, TestConnectivityBetweenHybridandIce) {
+  TestHybridConnectivity(cricket::ICEPROTO_RFC5245);
+}
+
+// This test verifies channel can handle Gice messages when channel is in
+// hybrid mode.
+TEST_F(P2PTransportChannelTest, TestConnectivityBetweenHybridandGice) {
+  TestHybridConnectivity(cricket::ICEPROTO_GOOGLE);
+}
+
+// Verify that we can set DSCP value and retrieve properly from P2PTC.
+TEST_F(P2PTransportChannelTest, TestDefaultDscpValue) {
+  AddAddress(0, kPublicAddrs[0]);
+  AddAddress(1, kPublicAddrs[1]);
+
+  CreateChannels(1);
+  EXPECT_EQ(rtc::DSCP_NO_CHANGE,
+            GetEndpoint(0)->cd1_.ch_->DefaultDscpValue());
+  EXPECT_EQ(rtc::DSCP_NO_CHANGE,
+            GetEndpoint(1)->cd1_.ch_->DefaultDscpValue());
+  GetEndpoint(0)->cd1_.ch_->SetOption(
+      rtc::Socket::OPT_DSCP, rtc::DSCP_CS6);
+  GetEndpoint(1)->cd1_.ch_->SetOption(
+      rtc::Socket::OPT_DSCP, rtc::DSCP_CS6);
+  EXPECT_EQ(rtc::DSCP_CS6,
+            GetEndpoint(0)->cd1_.ch_->DefaultDscpValue());
+  EXPECT_EQ(rtc::DSCP_CS6,
+            GetEndpoint(1)->cd1_.ch_->DefaultDscpValue());
+  GetEndpoint(0)->cd1_.ch_->SetOption(
+      rtc::Socket::OPT_DSCP, rtc::DSCP_AF41);
+  GetEndpoint(1)->cd1_.ch_->SetOption(
+      rtc::Socket::OPT_DSCP, rtc::DSCP_AF41);
+  EXPECT_EQ(rtc::DSCP_AF41,
+            GetEndpoint(0)->cd1_.ch_->DefaultDscpValue());
+  EXPECT_EQ(rtc::DSCP_AF41,
+            GetEndpoint(1)->cd1_.ch_->DefaultDscpValue());
+}
+
+// Verify IPv6 connection is preferred over IPv4.
+// Flaky: https://code.google.com/p/webrtc/issues/detail?id=3317
+TEST_F(P2PTransportChannelTest, DISABLED_TestIPv6Connections) {
+  AddAddress(0, kIPv6PublicAddrs[0]);
+  AddAddress(0, kPublicAddrs[0]);
+  AddAddress(1, kIPv6PublicAddrs[1]);
+  AddAddress(1, kPublicAddrs[1]);
+
+  SetAllocationStepDelay(0, kMinimumStepDelay);
+  SetAllocationStepDelay(1, kMinimumStepDelay);
+
+  // Enable IPv6
+  SetAllocatorFlags(0, cricket::PORTALLOCATOR_ENABLE_IPV6);
+  SetAllocatorFlags(1, cricket::PORTALLOCATOR_ENABLE_IPV6);
+
+  CreateChannels(1);
+
+  EXPECT_TRUE_WAIT(ep1_ch1()->readable() && ep1_ch1()->writable() &&
+                   ep2_ch1()->readable() && ep2_ch1()->writable(),
+                   1000);
+  EXPECT_TRUE(
+      ep1_ch1()->best_connection() && ep2_ch1()->best_connection() &&
+      LocalCandidate(ep1_ch1())->address().EqualIPs(kIPv6PublicAddrs[0]) &&
+      RemoteCandidate(ep1_ch1())->address().EqualIPs(kIPv6PublicAddrs[1]));
+
+  TestSendRecv(1);
+  DestroyChannels();
+}
+
+// Testing forceful TURN connections.
+TEST_F(P2PTransportChannelTest, TestForceTurn) {
+  ConfigureEndpoints(NAT_PORT_RESTRICTED, NAT_SYMMETRIC,
+                     kDefaultPortAllocatorFlags |
+                         cricket::PORTALLOCATOR_ENABLE_SHARED_SOCKET |
+                         cricket::PORTALLOCATOR_ENABLE_SHARED_UFRAG,
+                     kDefaultPortAllocatorFlags |
+                         cricket::PORTALLOCATOR_ENABLE_SHARED_SOCKET |
+                         cricket::PORTALLOCATOR_ENABLE_SHARED_UFRAG,
+                     kDefaultStepDelay, kDefaultStepDelay,
+                     cricket::ICEPROTO_RFC5245);
+  set_force_relay(true);
+
+  SetAllocationStepDelay(0, kMinimumStepDelay);
+  SetAllocationStepDelay(1, kMinimumStepDelay);
+
+  CreateChannels(1);
+
+  EXPECT_TRUE_WAIT(ep1_ch1()->readable() &&
+                   ep1_ch1()->writable() &&
+                   ep2_ch1()->readable() &&
+                   ep2_ch1()->writable(),
+                   1000);
+
+  EXPECT_TRUE(ep1_ch1()->best_connection() &&
+              ep2_ch1()->best_connection());
+
+  EXPECT_EQ("relay", RemoteCandidate(ep1_ch1())->type());
+  EXPECT_EQ("relay", LocalCandidate(ep1_ch1())->type());
+  EXPECT_EQ("relay", RemoteCandidate(ep2_ch1())->type());
+  EXPECT_EQ("relay", LocalCandidate(ep2_ch1())->type());
+
+  TestSendRecv(1);
+  DestroyChannels();
+}
+
+// Test what happens when we have 2 users behind the same NAT. This can lead
+// to interesting behavior because the STUN server will only give out the
+// address of the outermost NAT.
+class P2PTransportChannelSameNatTest : public P2PTransportChannelTestBase {
+ protected:
+  void ConfigureEndpoints(Config nat_type, Config config1, Config config2) {
+    ASSERT(nat_type >= NAT_FULL_CONE && nat_type <= NAT_SYMMETRIC);
+    rtc::NATSocketServer::Translator* outer_nat =
+        nat()->AddTranslator(kPublicAddrs[0], kNatAddrs[0],
+            static_cast<rtc::NATType>(nat_type - NAT_FULL_CONE));
+    ConfigureEndpoint(outer_nat, 0, config1);
+    ConfigureEndpoint(outer_nat, 1, config2);
+  }
+  void ConfigureEndpoint(rtc::NATSocketServer::Translator* nat,
+                         int endpoint, Config config) {
+    ASSERT(config <= NAT_SYMMETRIC);
+    if (config == OPEN) {
+      AddAddress(endpoint, kPrivateAddrs[endpoint]);
+      nat->AddClient(kPrivateAddrs[endpoint]);
+    } else {
+      AddAddress(endpoint, kCascadedPrivateAddrs[endpoint]);
+      nat->AddTranslator(kPrivateAddrs[endpoint], kCascadedNatAddrs[endpoint],
+          static_cast<rtc::NATType>(config - NAT_FULL_CONE))->AddClient(
+              kCascadedPrivateAddrs[endpoint]);
+    }
+  }
+};
+
+TEST_F(P2PTransportChannelSameNatTest, TestConesBehindSameCone) {
+  ConfigureEndpoints(NAT_FULL_CONE, NAT_FULL_CONE, NAT_FULL_CONE);
+  Test(kLocalUdpToStunUdp);
+}
+
+// Test what happens when we have multiple available pathways.
+// In the future we will try different RTTs and configs for the different
+// interfaces, so that we can simulate a user with Ethernet and VPN networks.
+class P2PTransportChannelMultihomedTest : public P2PTransportChannelTestBase {
+};
+
+// Test that we can establish connectivity when both peers are multihomed.
+TEST_F(P2PTransportChannelMultihomedTest, DISABLED_TestBasic) {
+  AddAddress(0, kPublicAddrs[0]);
+  AddAddress(0, kAlternateAddrs[0]);
+  AddAddress(1, kPublicAddrs[1]);
+  AddAddress(1, kAlternateAddrs[1]);
+  Test(kLocalUdpToLocalUdp);
+}
+
+// Test that we can quickly switch links if an interface goes down.
+TEST_F(P2PTransportChannelMultihomedTest, TestFailover) {
+  AddAddress(0, kPublicAddrs[0]);
+  // Adding alternate address will make sure |kPublicAddrs| has the higher
+  // priority than others. This is due to FakeNetwork::AddInterface method.
+  AddAddress(1, kAlternateAddrs[1]);
+  AddAddress(1, kPublicAddrs[1]);
+
+  // Use only local ports for simplicity.
+  SetAllocatorFlags(0, kOnlyLocalPorts);
+  SetAllocatorFlags(1, kOnlyLocalPorts);
+
+  // Create channels and let them go writable, as usual.
+  CreateChannels(1);
+  EXPECT_TRUE_WAIT(ep1_ch1()->readable() && ep1_ch1()->writable() &&
+                   ep2_ch1()->readable() && ep2_ch1()->writable(),
+                   1000);
+  EXPECT_TRUE(
+      ep1_ch1()->best_connection() && ep2_ch1()->best_connection() &&
+      LocalCandidate(ep1_ch1())->address().EqualIPs(kPublicAddrs[0]) &&
+      RemoteCandidate(ep1_ch1())->address().EqualIPs(kPublicAddrs[1]));
+
+  // Blackhole any traffic to or from the public addrs.
+  LOG(LS_INFO) << "Failing over...";
+  fw()->AddRule(false, rtc::FP_ANY, rtc::FD_ANY,
+                kPublicAddrs[1]);
+
+  // We should detect loss of connectivity within 5 seconds or so.
+  EXPECT_TRUE_WAIT(!ep1_ch1()->writable(), 7000);
+
+  // We should switch over to use the alternate addr immediately
+  // when we lose writability.
+  EXPECT_TRUE_WAIT(
+      ep1_ch1()->best_connection() && ep2_ch1()->best_connection() &&
+      LocalCandidate(ep1_ch1())->address().EqualIPs(kPublicAddrs[0]) &&
+      RemoteCandidate(ep1_ch1())->address().EqualIPs(kAlternateAddrs[1]),
+      3000);
+
+  DestroyChannels();
+}
+
+// Test that we can switch links in a coordinated fashion.
+TEST_F(P2PTransportChannelMultihomedTest, TestDrain) {
+  AddAddress(0, kPublicAddrs[0]);
+  AddAddress(1, kPublicAddrs[1]);
+  // Use only local ports for simplicity.
+  SetAllocatorFlags(0, kOnlyLocalPorts);
+  SetAllocatorFlags(1, kOnlyLocalPorts);
+
+  // Create channels and let them go writable, as usual.
+  CreateChannels(1);
+  EXPECT_TRUE_WAIT(ep1_ch1()->readable() && ep1_ch1()->writable() &&
+                   ep2_ch1()->readable() && ep2_ch1()->writable(),
+                   1000);
+  EXPECT_TRUE(
+      ep1_ch1()->best_connection() && ep2_ch1()->best_connection() &&
+      LocalCandidate(ep1_ch1())->address().EqualIPs(kPublicAddrs[0]) &&
+      RemoteCandidate(ep1_ch1())->address().EqualIPs(kPublicAddrs[1]));
+
+  // Remove the public interface, add the alternate interface, and allocate
+  // a new generation of candidates for the new interface (via Connect()).
+  LOG(LS_INFO) << "Draining...";
+  AddAddress(1, kAlternateAddrs[1]);
+  RemoveAddress(1, kPublicAddrs[1]);
+  ep2_ch1()->Connect();
+
+  // We should switch over to use the alternate address after
+  // an exchange of pings.
+  EXPECT_TRUE_WAIT(
+      ep1_ch1()->best_connection() && ep2_ch1()->best_connection() &&
+      LocalCandidate(ep1_ch1())->address().EqualIPs(kPublicAddrs[0]) &&
+      RemoteCandidate(ep1_ch1())->address().EqualIPs(kAlternateAddrs[1]),
+      3000);
+
+  DestroyChannels();
+}
diff --git a/webrtc/p2p/base/packetsocketfactory.h b/webrtc/p2p/base/packetsocketfactory.h
new file mode 100644
index 0000000..1f45fec
--- /dev/null
+++ b/webrtc/p2p/base/packetsocketfactory.h
@@ -0,0 +1,52 @@
+/*
+ *  Copyright 2011 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_PACKETSOCKETFACTORY_H_
+#define WEBRTC_P2P_BASE_PACKETSOCKETFACTORY_H_
+
+#include "webrtc/base/proxyinfo.h"
+
+namespace rtc {
+
+class AsyncPacketSocket;
+class AsyncResolverInterface;
+
+class PacketSocketFactory {
+ public:
+  enum Options {
+    OPT_SSLTCP = 0x01,  // Pseudo-TLS.
+    OPT_TLS = 0x02,
+    OPT_STUN = 0x04,
+  };
+
+  PacketSocketFactory() { }
+  virtual ~PacketSocketFactory() { }
+
+  virtual AsyncPacketSocket* CreateUdpSocket(
+      const SocketAddress& address, int min_port, int max_port) = 0;
+  virtual AsyncPacketSocket* CreateServerTcpSocket(
+      const SocketAddress& local_address, int min_port, int max_port,
+      int opts) = 0;
+
+  // TODO: |proxy_info| and |user_agent| should be set
+  // per-factory and not when socket is created.
+  virtual AsyncPacketSocket* CreateClientTcpSocket(
+      const SocketAddress& local_address, const SocketAddress& remote_address,
+      const ProxyInfo& proxy_info, const std::string& user_agent, int opts) = 0;
+
+  virtual AsyncResolverInterface* CreateAsyncResolver() = 0;
+
+ private:
+  DISALLOW_EVIL_CONSTRUCTORS(PacketSocketFactory);
+};
+
+}  // namespace rtc
+
+#endif  // WEBRTC_P2P_BASE_PACKETSOCKETFACTORY_H_
diff --git a/webrtc/p2p/base/parsing.cc b/webrtc/p2p/base/parsing.cc
new file mode 100644
index 0000000..04d7e79
--- /dev/null
+++ b/webrtc/p2p/base/parsing.cc
@@ -0,0 +1,141 @@
+/*
+ *  Copyright 2010 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/parsing.h"
+
+#include <stdlib.h>
+#include <algorithm>
+#include "webrtc/base/stringutils.h"
+
+namespace {
+static const char kTrue[] = "true";
+static const char kOne[] = "1";
+}
+
+namespace cricket {
+
+bool BadParse(const std::string& text, ParseError* err) {
+  if (err != NULL) {
+    err->text = text;
+  }
+  return false;
+}
+
+bool BadWrite(const std::string& text, WriteError* err) {
+  if (err != NULL) {
+    err->text = text;
+  }
+  return false;
+}
+
+std::string GetXmlAttr(const buzz::XmlElement* elem,
+                       const buzz::QName& name,
+                       const std::string& def) {
+  std::string val = elem->Attr(name);
+  return val.empty() ? def : val;
+}
+
+std::string GetXmlAttr(const buzz::XmlElement* elem,
+                       const buzz::QName& name,
+                       const char* def) {
+    return GetXmlAttr(elem, name, std::string(def));
+}
+
+bool GetXmlAttr(const buzz::XmlElement* elem,
+                const buzz::QName& name, bool def) {
+  std::string val = elem->Attr(name);
+  std::transform(val.begin(), val.end(), val.begin(), tolower);
+
+  return val.empty() ? def : (val == kTrue || val == kOne);
+}
+
+int GetXmlAttr(const buzz::XmlElement* elem,
+               const buzz::QName& name, int def) {
+  std::string val = elem->Attr(name);
+  return val.empty() ? def : atoi(val.c_str());
+}
+
+const buzz::XmlElement* GetXmlChild(const buzz::XmlElement* parent,
+                                    const std::string& name) {
+  for (const buzz::XmlElement* child = parent->FirstElement();
+       child != NULL;
+       child = child->NextElement()) {
+    if (child->Name().LocalPart() == name) {
+      return child;
+    }
+  }
+  return NULL;
+}
+
+bool RequireXmlChild(const buzz::XmlElement* parent,
+                     const std::string& name,
+                     const buzz::XmlElement** child,
+                     ParseError* error) {
+  *child = GetXmlChild(parent, name);
+  if (*child == NULL) {
+    return BadParse("element '" + parent->Name().Merged() +
+                    "' missing required child '" + name,
+                    error);
+  } else {
+    return true;
+  }
+}
+
+bool RequireXmlAttr(const buzz::XmlElement* elem,
+                    const buzz::QName& name,
+                    std::string* value,
+                    ParseError* error) {
+  if (!elem->HasAttr(name)) {
+    return BadParse("element '" + elem->Name().Merged() +
+                    "' missing required attribute '"
+                    + name.Merged() + "'",
+                    error);
+  } else {
+    *value = elem->Attr(name);
+    return true;
+  }
+}
+
+void AddXmlAttrIfNonEmpty(buzz::XmlElement* elem,
+                          const buzz::QName name,
+                          const std::string& value) {
+  if (!value.empty()) {
+    elem->AddAttr(name, value);
+  }
+}
+
+void AddXmlChildren(buzz::XmlElement* parent,
+                    const std::vector<buzz::XmlElement*>& children) {
+  for (std::vector<buzz::XmlElement*>::const_iterator iter = children.begin();
+       iter != children.end();
+       iter++) {
+    parent->AddElement(*iter);
+  }
+}
+
+void CopyXmlChildren(const buzz::XmlElement* source, buzz::XmlElement* dest) {
+  for (const buzz::XmlElement* child = source->FirstElement();
+       child != NULL;
+       child = child->NextElement()) {
+    dest->AddElement(new buzz::XmlElement(*child));
+  }
+}
+
+std::vector<buzz::XmlElement*> CopyOfXmlChildren(const buzz::XmlElement* elem) {
+  std::vector<buzz::XmlElement*> children;
+  for (const buzz::XmlElement* child = elem->FirstElement();
+       child != NULL;
+       child = child->NextElement()) {
+    children.push_back(new buzz::XmlElement(*child));
+  }
+  return children;
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/parsing.h b/webrtc/p2p/base/parsing.h
new file mode 100644
index 0000000..6b32b5d
--- /dev/null
+++ b/webrtc/p2p/base/parsing.h
@@ -0,0 +1,140 @@
+/*
+ *  Copyright 2010 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_PARSING_H_
+#define WEBRTC_P2P_BASE_PARSING_H_
+
+#include <string>
+#include <vector>
+#include "webrtc/libjingle/xmllite/xmlelement.h"  // Needed to delete ParseError.extra.
+#include "webrtc/base/basictypes.h"
+#include "webrtc/base/stringencode.h"
+
+namespace cricket {
+
+typedef std::vector<buzz::XmlElement*> XmlElements;
+
+// We decided "bool Parse(in, out*, error*)" is generally the best
+// parse signature.  "out Parse(in)" doesn't allow for errors.
+// "error* Parse(in, out*)" doesn't allow flexible memory management.
+
+// The error type for parsing.
+struct ParseError {
+ public:
+  // explains the error
+  std::string text;
+  // provide details about what wasn't parsable
+  const buzz::XmlElement* extra;
+
+  ParseError() : extra(NULL) {}
+
+  ~ParseError() {
+    delete extra;
+  }
+
+  void SetText(const std::string& text) {
+    this->text = text;
+  }
+};
+
+// The error type for writing.
+struct WriteError {
+  std::string text;
+
+  void SetText(const std::string& text) {
+    this->text = text;
+  }
+};
+
+// Convenience method for returning a message when parsing fails.
+bool BadParse(const std::string& text, ParseError* err);
+
+// Convenience method for returning a message when writing fails.
+bool BadWrite(const std::string& text, WriteError* error);
+
+// helper XML functions
+std::string GetXmlAttr(const buzz::XmlElement* elem,
+                       const buzz::QName& name,
+                       const std::string& def);
+std::string GetXmlAttr(const buzz::XmlElement* elem,
+                       const buzz::QName& name,
+                       const char* def);
+// Return true if the value is "true" or "1".
+bool GetXmlAttr(const buzz::XmlElement* elem,
+                const buzz::QName& name, bool def);
+int GetXmlAttr(const buzz::XmlElement* elem,
+               const buzz::QName& name, int def);
+
+template <class T>
+bool GetXmlAttr(const buzz::XmlElement* elem,
+                const buzz::QName& name,
+                T* val_out) {
+  if (!elem->HasAttr(name)) {
+    return false;
+  }
+  std::string unparsed = elem->Attr(name);
+  return rtc::FromString(unparsed, val_out);
+}
+
+template <class T>
+bool GetXmlAttr(const buzz::XmlElement* elem,
+                const buzz::QName& name,
+                const T& def,
+                T* val_out) {
+  if (!elem->HasAttr(name)) {
+    *val_out = def;
+    return true;
+  }
+  return GetXmlAttr(elem, name, val_out);
+}
+
+template <class T>
+bool AddXmlAttr(buzz::XmlElement* elem,
+                const buzz::QName& name, const T& val) {
+  std::string buf;
+  if (!rtc::ToString(val, &buf)) {
+    return false;
+  }
+  elem->AddAttr(name, buf);
+  return true;
+}
+
+template <class T>
+bool SetXmlBody(buzz::XmlElement* elem, const T& val) {
+  std::string buf;
+  if (!rtc::ToString(val, &buf)) {
+    return false;
+  }
+  elem->SetBodyText(buf);
+  return true;
+}
+
+const buzz::XmlElement* GetXmlChild(const buzz::XmlElement* parent,
+                                    const std::string& name);
+
+bool RequireXmlChild(const buzz::XmlElement* parent,
+                     const std::string& name,
+                     const buzz::XmlElement** child,
+                     ParseError* error);
+bool RequireXmlAttr(const buzz::XmlElement* elem,
+                    const buzz::QName& name,
+                    std::string* value,
+                    ParseError* error);
+void AddXmlAttrIfNonEmpty(buzz::XmlElement* elem,
+                          const buzz::QName name,
+                          const std::string& value);
+void AddXmlChildren(buzz::XmlElement* parent,
+                    const std::vector<buzz::XmlElement*>& children);
+void CopyXmlChildren(const buzz::XmlElement* source, buzz::XmlElement* dest);
+std::vector<buzz::XmlElement*> CopyOfXmlChildren(const buzz::XmlElement* elem);
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_PARSING_H_
diff --git a/webrtc/p2p/base/port.cc b/webrtc/p2p/base/port.cc
new file mode 100644
index 0000000..f569d9f
--- /dev/null
+++ b/webrtc/p2p/base/port.cc
@@ -0,0 +1,1430 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/port.h"
+
+#include <algorithm>
+#include <vector>
+
+#include "webrtc/p2p/base/common.h"
+#include "webrtc/p2p/base/portallocator.h"
+#include "webrtc/base/base64.h"
+#include "webrtc/base/crc32.h"
+#include "webrtc/base/helpers.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/messagedigest.h"
+#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/stringencode.h"
+#include "webrtc/base/stringutils.h"
+
+namespace {
+
+// Determines whether we have seen at least the given maximum number of
+// pings fail to have a response.
+inline bool TooManyFailures(
+    const std::vector<uint32>& pings_since_last_response,
+    uint32 maximum_failures,
+    uint32 rtt_estimate,
+    uint32 now) {
+
+  // If we haven't sent that many pings, then we can't have failed that many.
+  if (pings_since_last_response.size() < maximum_failures)
+    return false;
+
+  // Check if the window in which we would expect a response to the ping has
+  // already elapsed.
+  return pings_since_last_response[maximum_failures - 1] + rtt_estimate < now;
+}
+
+// Determines whether we have gone too long without seeing any response.
+inline bool TooLongWithoutResponse(
+    const std::vector<uint32>& pings_since_last_response,
+    uint32 maximum_time,
+    uint32 now) {
+
+  if (pings_since_last_response.size() == 0)
+    return false;
+
+  return pings_since_last_response[0] + maximum_time < now;
+}
+
+// GICE(ICEPROTO_GOOGLE) requires different username for RTP and RTCP.
+// This function generates a different username by +1 on the last character of
+// the given username (|rtp_ufrag|).
+std::string GetRtcpUfragFromRtpUfrag(const std::string& rtp_ufrag) {
+  ASSERT(!rtp_ufrag.empty());
+  if (rtp_ufrag.empty()) {
+    return rtp_ufrag;
+  }
+  // Change the last character to the one next to it in the base64 table.
+  char new_last_char;
+  if (!rtc::Base64::GetNextBase64Char(rtp_ufrag[rtp_ufrag.size() - 1],
+                                            &new_last_char)) {
+    // Should not be here.
+    ASSERT(false);
+  }
+  std::string rtcp_ufrag = rtp_ufrag;
+  rtcp_ufrag[rtcp_ufrag.size() - 1] = new_last_char;
+  ASSERT(rtcp_ufrag != rtp_ufrag);
+  return rtcp_ufrag;
+}
+
+// We will restrict RTT estimates (when used for determining state) to be
+// within a reasonable range.
+const uint32 MINIMUM_RTT = 100;   // 0.1 seconds
+const uint32 MAXIMUM_RTT = 3000;  // 3 seconds
+
+// When we don't have any RTT data, we have to pick something reasonable.  We
+// use a large value just in case the connection is really slow.
+const uint32 DEFAULT_RTT = MAXIMUM_RTT;
+
+// Computes our estimate of the RTT given the current estimate.
+inline uint32 ConservativeRTTEstimate(uint32 rtt) {
+  return rtc::_max(MINIMUM_RTT, rtc::_min(MAXIMUM_RTT, 2 * rtt));
+}
+
+// Weighting of the old rtt value to new data.
+const int RTT_RATIO = 3;  // 3 : 1
+
+// The delay before we begin checking if this port is useless.
+const int kPortTimeoutDelay = 30 * 1000;  // 30 seconds
+
+// Used by the Connection.
+const uint32 MSG_DELETE = 1;
+}
+
+namespace cricket {
+
+// TODO(ronghuawu): Use "host", "srflx", "prflx" and "relay". But this requires
+// the signaling part be updated correspondingly as well.
+const char LOCAL_PORT_TYPE[] = "local";
+const char STUN_PORT_TYPE[] = "stun";
+const char PRFLX_PORT_TYPE[] = "prflx";
+const char RELAY_PORT_TYPE[] = "relay";
+
+const char UDP_PROTOCOL_NAME[] = "udp";
+const char TCP_PROTOCOL_NAME[] = "tcp";
+const char SSLTCP_PROTOCOL_NAME[] = "ssltcp";
+
+static const char* const PROTO_NAMES[] = { UDP_PROTOCOL_NAME,
+                                           TCP_PROTOCOL_NAME,
+                                           SSLTCP_PROTOCOL_NAME };
+
+const char* ProtoToString(ProtocolType proto) {
+  return PROTO_NAMES[proto];
+}
+
+bool StringToProto(const char* value, ProtocolType* proto) {
+  for (size_t i = 0; i <= PROTO_LAST; ++i) {
+    if (_stricmp(PROTO_NAMES[i], value) == 0) {
+      *proto = static_cast<ProtocolType>(i);
+      return true;
+    }
+  }
+  return false;
+}
+
+// RFC 6544, TCP candidate encoding rules.
+const int DISCARD_PORT = 9;
+const char TCPTYPE_ACTIVE_STR[] = "active";
+const char TCPTYPE_PASSIVE_STR[] = "passive";
+const char TCPTYPE_SIMOPEN_STR[] = "so";
+
+// Foundation:  An arbitrary string that is the same for two candidates
+//   that have the same type, base IP address, protocol (UDP, TCP,
+//   etc.), and STUN or TURN server.  If any of these are different,
+//   then the foundation will be different.  Two candidate pairs with
+//   the same foundation pairs are likely to have similar network
+//   characteristics.  Foundations are used in the frozen algorithm.
+static std::string ComputeFoundation(
+    const std::string& type,
+    const std::string& protocol,
+    const rtc::SocketAddress& base_address) {
+  std::ostringstream ost;
+  ost << type << base_address.ipaddr().ToString() << protocol;
+  return rtc::ToString<uint32>(rtc::ComputeCrc32(ost.str()));
+}
+
+Port::Port(rtc::Thread* thread, rtc::PacketSocketFactory* factory,
+           rtc::Network* network, const rtc::IPAddress& ip,
+           const std::string& username_fragment, const std::string& password)
+    : thread_(thread),
+      factory_(factory),
+      send_retransmit_count_attribute_(false),
+      network_(network),
+      ip_(ip),
+      min_port_(0),
+      max_port_(0),
+      component_(ICE_CANDIDATE_COMPONENT_DEFAULT),
+      generation_(0),
+      ice_username_fragment_(username_fragment),
+      password_(password),
+      timeout_delay_(kPortTimeoutDelay),
+      enable_port_packets_(false),
+      ice_protocol_(ICEPROTO_HYBRID),
+      ice_role_(ICEROLE_UNKNOWN),
+      tiebreaker_(0),
+      shared_socket_(true),
+      candidate_filter_(CF_ALL) {
+  Construct();
+}
+
+Port::Port(rtc::Thread* thread, const std::string& type,
+           rtc::PacketSocketFactory* factory,
+           rtc::Network* network, const rtc::IPAddress& ip,
+           int min_port, int max_port, const std::string& username_fragment,
+           const std::string& password)
+    : thread_(thread),
+      factory_(factory),
+      type_(type),
+      send_retransmit_count_attribute_(false),
+      network_(network),
+      ip_(ip),
+      min_port_(min_port),
+      max_port_(max_port),
+      component_(ICE_CANDIDATE_COMPONENT_DEFAULT),
+      generation_(0),
+      ice_username_fragment_(username_fragment),
+      password_(password),
+      timeout_delay_(kPortTimeoutDelay),
+      enable_port_packets_(false),
+      ice_protocol_(ICEPROTO_HYBRID),
+      ice_role_(ICEROLE_UNKNOWN),
+      tiebreaker_(0),
+      shared_socket_(false),
+      candidate_filter_(CF_ALL) {
+  ASSERT(factory_ != NULL);
+  Construct();
+}
+
+void Port::Construct() {
+  // If the username_fragment and password are empty, we should just create one.
+  if (ice_username_fragment_.empty()) {
+    ASSERT(password_.empty());
+    ice_username_fragment_ = rtc::CreateRandomString(ICE_UFRAG_LENGTH);
+    password_ = rtc::CreateRandomString(ICE_PWD_LENGTH);
+  }
+  LOG_J(LS_INFO, this) << "Port created";
+}
+
+Port::~Port() {
+  // Delete all of the remaining connections.  We copy the list up front
+  // because each deletion will cause it to be modified.
+
+  std::vector<Connection*> list;
+
+  AddressMap::iterator iter = connections_.begin();
+  while (iter != connections_.end()) {
+    list.push_back(iter->second);
+    ++iter;
+  }
+
+  for (uint32 i = 0; i < list.size(); i++)
+    delete list[i];
+}
+
+Connection* Port::GetConnection(const rtc::SocketAddress& remote_addr) {
+  AddressMap::const_iterator iter = connections_.find(remote_addr);
+  if (iter != connections_.end())
+    return iter->second;
+  else
+    return NULL;
+}
+
+void Port::AddAddress(const rtc::SocketAddress& address,
+                      const rtc::SocketAddress& base_address,
+                      const rtc::SocketAddress& related_address,
+                      const std::string& protocol,
+                      const std::string& tcptype,
+                      const std::string& type,
+                      uint32 type_preference,
+                      uint32 relay_preference,
+                      bool final) {
+  if (protocol == TCP_PROTOCOL_NAME && type == LOCAL_PORT_TYPE) {
+    ASSERT(!tcptype.empty());
+  }
+
+  Candidate c;
+  c.set_id(rtc::CreateRandomString(8));
+  c.set_component(component_);
+  c.set_type(type);
+  c.set_protocol(protocol);
+  c.set_tcptype(tcptype);
+  c.set_address(address);
+  c.set_priority(c.GetPriority(type_preference, network_->preference(),
+                               relay_preference));
+  c.set_username(username_fragment());
+  c.set_password(password_);
+  c.set_network_name(network_->name());
+  c.set_generation(generation_);
+  c.set_related_address(related_address);
+  c.set_foundation(ComputeFoundation(type, protocol, base_address));
+  candidates_.push_back(c);
+  SignalCandidateReady(this, c);
+
+  if (final) {
+    SignalPortComplete(this);
+  }
+}
+
+void Port::AddConnection(Connection* conn) {
+  connections_[conn->remote_candidate().address()] = conn;
+  conn->SignalDestroyed.connect(this, &Port::OnConnectionDestroyed);
+  SignalConnectionCreated(this, conn);
+}
+
+void Port::OnReadPacket(
+    const char* data, size_t size, const rtc::SocketAddress& addr,
+    ProtocolType proto) {
+  // If the user has enabled port packets, just hand this over.
+  if (enable_port_packets_) {
+    SignalReadPacket(this, data, size, addr);
+    return;
+  }
+
+  // If this is an authenticated STUN request, then signal unknown address and
+  // send back a proper binding response.
+  rtc::scoped_ptr<IceMessage> msg;
+  std::string remote_username;
+  if (!GetStunMessage(data, size, addr, msg.accept(), &remote_username)) {
+    LOG_J(LS_ERROR, this) << "Received non-STUN packet from unknown address ("
+                          << addr.ToSensitiveString() << ")";
+  } else if (!msg) {
+    // STUN message handled already
+  } else if (msg->type() == STUN_BINDING_REQUEST) {
+    // Check for role conflicts.
+    if (IsStandardIce() &&
+        !MaybeIceRoleConflict(addr, msg.get(), remote_username)) {
+      LOG(LS_INFO) << "Received conflicting role from the peer.";
+      return;
+    }
+
+    SignalUnknownAddress(this, addr, proto, msg.get(), remote_username, false);
+  } else {
+    // NOTE(tschmelcher): STUN_BINDING_RESPONSE is benign. It occurs if we
+    // pruned a connection for this port while it had STUN requests in flight,
+    // because we then get back responses for them, which this code correctly
+    // does not handle.
+    if (msg->type() != STUN_BINDING_RESPONSE) {
+      LOG_J(LS_ERROR, this) << "Received unexpected STUN message type ("
+                            << msg->type() << ") from unknown address ("
+                            << addr.ToSensitiveString() << ")";
+    }
+  }
+}
+
+void Port::OnReadyToSend() {
+  AddressMap::iterator iter = connections_.begin();
+  for (; iter != connections_.end(); ++iter) {
+    iter->second->OnReadyToSend();
+  }
+}
+
+size_t Port::AddPrflxCandidate(const Candidate& local) {
+  candidates_.push_back(local);
+  return (candidates_.size() - 1);
+}
+
+bool Port::IsStandardIce() const {
+  return (ice_protocol_ == ICEPROTO_RFC5245);
+}
+
+bool Port::IsGoogleIce() const {
+  return (ice_protocol_ == ICEPROTO_GOOGLE);
+}
+
+bool Port::IsHybridIce() const {
+  return (ice_protocol_ == ICEPROTO_HYBRID);
+}
+
+bool Port::GetStunMessage(const char* data, size_t size,
+                          const rtc::SocketAddress& addr,
+                          IceMessage** out_msg, std::string* out_username) {
+  // NOTE: This could clearly be optimized to avoid allocating any memory.
+  //       However, at the data rates we'll be looking at on the client side,
+  //       this probably isn't worth worrying about.
+  ASSERT(out_msg != NULL);
+  ASSERT(out_username != NULL);
+  *out_msg = NULL;
+  out_username->clear();
+
+  // Don't bother parsing the packet if we can tell it's not STUN.
+  // In ICE mode, all STUN packets will have a valid fingerprint.
+  if (IsStandardIce() && !StunMessage::ValidateFingerprint(data, size)) {
+    return false;
+  }
+
+  // Parse the request message.  If the packet is not a complete and correct
+  // STUN message, then ignore it.
+  rtc::scoped_ptr<IceMessage> stun_msg(new IceMessage());
+  rtc::ByteBuffer buf(data, size);
+  if (!stun_msg->Read(&buf) || (buf.Length() > 0)) {
+    return false;
+  }
+
+  if (stun_msg->type() == STUN_BINDING_REQUEST) {
+    // Check for the presence of USERNAME and MESSAGE-INTEGRITY (if ICE) first.
+    // If not present, fail with a 400 Bad Request.
+    if (!stun_msg->GetByteString(STUN_ATTR_USERNAME) ||
+        (IsStandardIce() &&
+         !stun_msg->GetByteString(STUN_ATTR_MESSAGE_INTEGRITY))) {
+      LOG_J(LS_ERROR, this) << "Received STUN request without username/M-I "
+                            << "from " << addr.ToSensitiveString();
+      SendBindingErrorResponse(stun_msg.get(), addr, STUN_ERROR_BAD_REQUEST,
+                               STUN_ERROR_REASON_BAD_REQUEST);
+      return true;
+    }
+
+    // If the username is bad or unknown, fail with a 401 Unauthorized.
+    std::string local_ufrag;
+    std::string remote_ufrag;
+    IceProtocolType remote_protocol_type;
+    if (!ParseStunUsername(stun_msg.get(), &local_ufrag, &remote_ufrag,
+                           &remote_protocol_type) ||
+        local_ufrag != username_fragment()) {
+      LOG_J(LS_ERROR, this) << "Received STUN request with bad local username "
+                            << local_ufrag << " from "
+                            << addr.ToSensitiveString();
+      SendBindingErrorResponse(stun_msg.get(), addr, STUN_ERROR_UNAUTHORIZED,
+                               STUN_ERROR_REASON_UNAUTHORIZED);
+      return true;
+    }
+
+    // Port is initialized to GOOGLE-ICE protocol type. If pings from remote
+    // are received before the signal message, protocol type may be different.
+    // Based on the STUN username, we can determine what's the remote protocol.
+    // This also enables us to send the response back using the same protocol
+    // as the request.
+    if (IsHybridIce()) {
+      SetIceProtocolType(remote_protocol_type);
+    }
+
+    // If ICE, and the MESSAGE-INTEGRITY is bad, fail with a 401 Unauthorized
+    if (IsStandardIce() &&
+        !stun_msg->ValidateMessageIntegrity(data, size, password_)) {
+      LOG_J(LS_ERROR, this) << "Received STUN request with bad M-I "
+                            << "from " << addr.ToSensitiveString();
+      SendBindingErrorResponse(stun_msg.get(), addr, STUN_ERROR_UNAUTHORIZED,
+                               STUN_ERROR_REASON_UNAUTHORIZED);
+      return true;
+    }
+    out_username->assign(remote_ufrag);
+  } else if ((stun_msg->type() == STUN_BINDING_RESPONSE) ||
+             (stun_msg->type() == STUN_BINDING_ERROR_RESPONSE)) {
+    if (stun_msg->type() == STUN_BINDING_ERROR_RESPONSE) {
+      if (const StunErrorCodeAttribute* error_code = stun_msg->GetErrorCode()) {
+        LOG_J(LS_ERROR, this) << "Received STUN binding error:"
+                              << " class=" << error_code->eclass()
+                              << " number=" << error_code->number()
+                              << " reason='" << error_code->reason() << "'"
+                              << " from " << addr.ToSensitiveString();
+        // Return message to allow error-specific processing
+      } else {
+        LOG_J(LS_ERROR, this) << "Received STUN binding error without a error "
+                              << "code from " << addr.ToSensitiveString();
+        return true;
+      }
+    }
+    // NOTE: Username should not be used in verifying response messages.
+    out_username->clear();
+  } else if (stun_msg->type() == STUN_BINDING_INDICATION) {
+    LOG_J(LS_VERBOSE, this) << "Received STUN binding indication:"
+                            << " from " << addr.ToSensitiveString();
+    out_username->clear();
+    // No stun attributes will be verified, if it's stun indication message.
+    // Returning from end of the this method.
+  } else {
+    LOG_J(LS_ERROR, this) << "Received STUN packet with invalid type ("
+                          << stun_msg->type() << ") from "
+                          << addr.ToSensitiveString();
+    return true;
+  }
+
+  // Return the STUN message found.
+  *out_msg = stun_msg.release();
+  return true;
+}
+
+bool Port::IsCompatibleAddress(const rtc::SocketAddress& addr) {
+  int family = ip().family();
+  // We use single-stack sockets, so families must match.
+  if (addr.family() != family) {
+    return false;
+  }
+  // Link-local IPv6 ports can only connect to other link-local IPv6 ports.
+  if (family == AF_INET6 && (IPIsPrivate(ip()) != IPIsPrivate(addr.ipaddr()))) {
+    return false;
+  }
+  return true;
+}
+
+bool Port::ParseStunUsername(const StunMessage* stun_msg,
+                             std::string* local_ufrag,
+                             std::string* remote_ufrag,
+                             IceProtocolType* remote_protocol_type) const {
+  // The packet must include a username that either begins or ends with our
+  // fragment.  It should begin with our fragment if it is a request and it
+  // should end with our fragment if it is a response.
+  local_ufrag->clear();
+  remote_ufrag->clear();
+  const StunByteStringAttribute* username_attr =
+        stun_msg->GetByteString(STUN_ATTR_USERNAME);
+  if (username_attr == NULL)
+    return false;
+
+  const std::string username_attr_str = username_attr->GetString();
+  size_t colon_pos = username_attr_str.find(":");
+  // If we are in hybrid mode set the appropriate ice protocol type based on
+  // the username argument style.
+  if (IsHybridIce()) {
+    *remote_protocol_type = (colon_pos != std::string::npos) ?
+        ICEPROTO_RFC5245 : ICEPROTO_GOOGLE;
+  } else {
+    *remote_protocol_type = ice_protocol_;
+  }
+  if (*remote_protocol_type == ICEPROTO_RFC5245) {
+    if (colon_pos != std::string::npos) {  // RFRAG:LFRAG
+      *local_ufrag = username_attr_str.substr(0, colon_pos);
+      *remote_ufrag = username_attr_str.substr(
+          colon_pos + 1, username_attr_str.size());
+    } else {
+      return false;
+    }
+  } else if (*remote_protocol_type == ICEPROTO_GOOGLE) {
+    int remote_frag_len = static_cast<int>(username_attr_str.size());
+    remote_frag_len -= static_cast<int>(username_fragment().size());
+    if (remote_frag_len < 0)
+      return false;
+
+    *local_ufrag = username_attr_str.substr(0, username_fragment().size());
+    *remote_ufrag = username_attr_str.substr(
+        username_fragment().size(), username_attr_str.size());
+  }
+  return true;
+}
+
+bool Port::MaybeIceRoleConflict(
+    const rtc::SocketAddress& addr, IceMessage* stun_msg,
+    const std::string& remote_ufrag) {
+  // Validate ICE_CONTROLLING or ICE_CONTROLLED attributes.
+  bool ret = true;
+  IceRole remote_ice_role = ICEROLE_UNKNOWN;
+  uint64 remote_tiebreaker = 0;
+  const StunUInt64Attribute* stun_attr =
+      stun_msg->GetUInt64(STUN_ATTR_ICE_CONTROLLING);
+  if (stun_attr) {
+    remote_ice_role = ICEROLE_CONTROLLING;
+    remote_tiebreaker = stun_attr->value();
+  }
+
+  // If |remote_ufrag| is same as port local username fragment and
+  // tie breaker value received in the ping message matches port
+  // tiebreaker value this must be a loopback call.
+  // We will treat this as valid scenario.
+  if (remote_ice_role == ICEROLE_CONTROLLING &&
+      username_fragment() == remote_ufrag &&
+      remote_tiebreaker == IceTiebreaker()) {
+    return true;
+  }
+
+  stun_attr = stun_msg->GetUInt64(STUN_ATTR_ICE_CONTROLLED);
+  if (stun_attr) {
+    remote_ice_role = ICEROLE_CONTROLLED;
+    remote_tiebreaker = stun_attr->value();
+  }
+
+  switch (ice_role_) {
+    case ICEROLE_CONTROLLING:
+      if (ICEROLE_CONTROLLING == remote_ice_role) {
+        if (remote_tiebreaker >= tiebreaker_) {
+          SignalRoleConflict(this);
+        } else {
+          // Send Role Conflict (487) error response.
+          SendBindingErrorResponse(stun_msg, addr,
+              STUN_ERROR_ROLE_CONFLICT, STUN_ERROR_REASON_ROLE_CONFLICT);
+          ret = false;
+        }
+      }
+      break;
+    case ICEROLE_CONTROLLED:
+      if (ICEROLE_CONTROLLED == remote_ice_role) {
+        if (remote_tiebreaker < tiebreaker_) {
+          SignalRoleConflict(this);
+        } else {
+          // Send Role Conflict (487) error response.
+          SendBindingErrorResponse(stun_msg, addr,
+              STUN_ERROR_ROLE_CONFLICT, STUN_ERROR_REASON_ROLE_CONFLICT);
+          ret = false;
+        }
+      }
+      break;
+    default:
+      ASSERT(false);
+  }
+  return ret;
+}
+
+void Port::CreateStunUsername(const std::string& remote_username,
+                              std::string* stun_username_attr_str) const {
+  stun_username_attr_str->clear();
+  *stun_username_attr_str = remote_username;
+  if (IsStandardIce()) {
+    // Connectivity checks from L->R will have username RFRAG:LFRAG.
+    stun_username_attr_str->append(":");
+  }
+  stun_username_attr_str->append(username_fragment());
+}
+
+void Port::SendBindingResponse(StunMessage* request,
+                               const rtc::SocketAddress& addr) {
+  ASSERT(request->type() == STUN_BINDING_REQUEST);
+
+  // Retrieve the username from the request.
+  const StunByteStringAttribute* username_attr =
+      request->GetByteString(STUN_ATTR_USERNAME);
+  ASSERT(username_attr != NULL);
+  if (username_attr == NULL) {
+    // No valid username, skip the response.
+    return;
+  }
+
+  // Fill in the response message.
+  StunMessage response;
+  response.SetType(STUN_BINDING_RESPONSE);
+  response.SetTransactionID(request->transaction_id());
+  const StunUInt32Attribute* retransmit_attr =
+      request->GetUInt32(STUN_ATTR_RETRANSMIT_COUNT);
+  if (retransmit_attr) {
+    // Inherit the incoming retransmit value in the response so the other side
+    // can see our view of lost pings.
+    response.AddAttribute(new StunUInt32Attribute(
+        STUN_ATTR_RETRANSMIT_COUNT, retransmit_attr->value()));
+
+    if (retransmit_attr->value() > CONNECTION_WRITE_CONNECT_FAILURES) {
+      LOG_J(LS_INFO, this)
+          << "Received a remote ping with high retransmit count: "
+          << retransmit_attr->value();
+    }
+  }
+
+  // Only GICE messages have USERNAME and MAPPED-ADDRESS in the response.
+  // ICE messages use XOR-MAPPED-ADDRESS, and add MESSAGE-INTEGRITY.
+  if (IsStandardIce()) {
+    response.AddAttribute(
+        new StunXorAddressAttribute(STUN_ATTR_XOR_MAPPED_ADDRESS, addr));
+    response.AddMessageIntegrity(password_);
+    response.AddFingerprint();
+  } else if (IsGoogleIce()) {
+    response.AddAttribute(
+        new StunAddressAttribute(STUN_ATTR_MAPPED_ADDRESS, addr));
+    response.AddAttribute(new StunByteStringAttribute(
+        STUN_ATTR_USERNAME, username_attr->GetString()));
+  }
+
+  // Send the response message.
+  rtc::ByteBuffer buf;
+  response.Write(&buf);
+  rtc::PacketOptions options(DefaultDscpValue());
+  if (SendTo(buf.Data(), buf.Length(), addr, options, false) < 0) {
+    LOG_J(LS_ERROR, this) << "Failed to send STUN ping response to "
+                          << addr.ToSensitiveString();
+  }
+
+  // The fact that we received a successful request means that this connection
+  // (if one exists) should now be readable.
+  Connection* conn = GetConnection(addr);
+  ASSERT(conn != NULL);
+  if (conn)
+    conn->ReceivedPing();
+}
+
+void Port::SendBindingErrorResponse(StunMessage* request,
+                                    const rtc::SocketAddress& addr,
+                                    int error_code, const std::string& reason) {
+  ASSERT(request->type() == STUN_BINDING_REQUEST);
+
+  // Fill in the response message.
+  StunMessage response;
+  response.SetType(STUN_BINDING_ERROR_RESPONSE);
+  response.SetTransactionID(request->transaction_id());
+
+  // When doing GICE, we need to write out the error code incorrectly to
+  // maintain backwards compatiblility.
+  StunErrorCodeAttribute* error_attr = StunAttribute::CreateErrorCode();
+  if (IsStandardIce()) {
+    error_attr->SetCode(error_code);
+  } else if (IsGoogleIce()) {
+    error_attr->SetClass(error_code / 256);
+    error_attr->SetNumber(error_code % 256);
+  }
+  error_attr->SetReason(reason);
+  response.AddAttribute(error_attr);
+
+  if (IsStandardIce()) {
+    // Per Section 10.1.2, certain error cases don't get a MESSAGE-INTEGRITY,
+    // because we don't have enough information to determine the shared secret.
+    if (error_code != STUN_ERROR_BAD_REQUEST &&
+        error_code != STUN_ERROR_UNAUTHORIZED)
+      response.AddMessageIntegrity(password_);
+    response.AddFingerprint();
+  } else if (IsGoogleIce()) {
+    // GICE responses include a username, if one exists.
+    const StunByteStringAttribute* username_attr =
+        request->GetByteString(STUN_ATTR_USERNAME);
+    if (username_attr)
+      response.AddAttribute(new StunByteStringAttribute(
+          STUN_ATTR_USERNAME, username_attr->GetString()));
+  }
+
+  // Send the response message.
+  rtc::ByteBuffer buf;
+  response.Write(&buf);
+  rtc::PacketOptions options(DefaultDscpValue());
+  SendTo(buf.Data(), buf.Length(), addr, options, false);
+  LOG_J(LS_INFO, this) << "Sending STUN binding error: reason=" << reason
+                       << " to " << addr.ToSensitiveString();
+}
+
+void Port::OnMessage(rtc::Message *pmsg) {
+  ASSERT(pmsg->message_id == MSG_CHECKTIMEOUT);
+  CheckTimeout();
+}
+
+std::string Port::ToString() const {
+  std::stringstream ss;
+  ss << "Port[" << content_name_ << ":" << component_
+     << ":" << generation_ << ":" << type_
+     << ":" << network_->ToString() << "]";
+  return ss.str();
+}
+
+void Port::EnablePortPackets() {
+  enable_port_packets_ = true;
+}
+
+void Port::OnConnectionDestroyed(Connection* conn) {
+  AddressMap::iterator iter =
+      connections_.find(conn->remote_candidate().address());
+  ASSERT(iter != connections_.end());
+  connections_.erase(iter);
+
+  // On the controlled side, ports time out, but only after all connections
+  // fail.  Note: If a new connection is added after this message is posted,
+  // but it fails and is removed before kPortTimeoutDelay, then this message
+  //  will still cause the Port to be destroyed.
+  if (ice_role_ == ICEROLE_CONTROLLED)
+    thread_->PostDelayed(timeout_delay_, this, MSG_CHECKTIMEOUT);
+}
+
+void Port::Destroy() {
+  ASSERT(connections_.empty());
+  LOG_J(LS_INFO, this) << "Port deleted";
+  SignalDestroyed(this);
+  delete this;
+}
+
+void Port::CheckTimeout() {
+  ASSERT(ice_role_ == ICEROLE_CONTROLLED);
+  // If this port has no connections, then there's no reason to keep it around.
+  // When the connections time out (both read and write), they will delete
+  // themselves, so if we have any connections, they are either readable or
+  // writable (or still connecting).
+  if (connections_.empty())
+    Destroy();
+}
+
+const std::string Port::username_fragment() const {
+  if (!IsStandardIce() &&
+      component_ == ICE_CANDIDATE_COMPONENT_RTCP) {
+    // In GICE mode, we should adjust username fragment for rtcp component.
+    return GetRtcpUfragFromRtpUfrag(ice_username_fragment_);
+  } else {
+    return ice_username_fragment_;
+  }
+}
+
+// A ConnectionRequest is a simple STUN ping used to determine writability.
+class ConnectionRequest : public StunRequest {
+ public:
+  explicit ConnectionRequest(Connection* connection)
+      : StunRequest(new IceMessage()),
+        connection_(connection) {
+  }
+
+  virtual ~ConnectionRequest() {
+  }
+
+  virtual void Prepare(StunMessage* request) {
+    request->SetType(STUN_BINDING_REQUEST);
+    std::string username;
+    connection_->port()->CreateStunUsername(
+        connection_->remote_candidate().username(), &username);
+    request->AddAttribute(
+        new StunByteStringAttribute(STUN_ATTR_USERNAME, username));
+
+    // connection_ already holds this ping, so subtract one from count.
+    if (connection_->port()->send_retransmit_count_attribute()) {
+      request->AddAttribute(new StunUInt32Attribute(
+          STUN_ATTR_RETRANSMIT_COUNT,
+          static_cast<uint32>(
+              connection_->pings_since_last_response_.size() - 1)));
+    }
+
+    // Adding ICE-specific attributes to the STUN request message.
+    if (connection_->port()->IsStandardIce()) {
+      // Adding ICE_CONTROLLED or ICE_CONTROLLING attribute based on the role.
+      if (connection_->port()->GetIceRole() == ICEROLE_CONTROLLING) {
+        request->AddAttribute(new StunUInt64Attribute(
+            STUN_ATTR_ICE_CONTROLLING, connection_->port()->IceTiebreaker()));
+        // Since we are trying aggressive nomination, sending USE-CANDIDATE
+        // attribute in every ping.
+        // If we are dealing with a ice-lite end point, nomination flag
+        // in Connection will be set to false by default. Once the connection
+        // becomes "best connection", nomination flag will be turned on.
+        if (connection_->use_candidate_attr()) {
+          request->AddAttribute(new StunByteStringAttribute(
+              STUN_ATTR_USE_CANDIDATE));
+        }
+      } else if (connection_->port()->GetIceRole() == ICEROLE_CONTROLLED) {
+        request->AddAttribute(new StunUInt64Attribute(
+            STUN_ATTR_ICE_CONTROLLED, connection_->port()->IceTiebreaker()));
+      } else {
+        ASSERT(false);
+      }
+
+      // Adding PRIORITY Attribute.
+      // Changing the type preference to Peer Reflexive and local preference
+      // and component id information is unchanged from the original priority.
+      // priority = (2^24)*(type preference) +
+      //           (2^8)*(local preference) +
+      //           (2^0)*(256 - component ID)
+      uint32 prflx_priority = ICE_TYPE_PREFERENCE_PRFLX << 24 |
+          (connection_->local_candidate().priority() & 0x00FFFFFF);
+      request->AddAttribute(
+          new StunUInt32Attribute(STUN_ATTR_PRIORITY, prflx_priority));
+
+      // Adding Message Integrity attribute.
+      request->AddMessageIntegrity(connection_->remote_candidate().password());
+      // Adding Fingerprint.
+      request->AddFingerprint();
+    }
+  }
+
+  virtual void OnResponse(StunMessage* response) {
+    connection_->OnConnectionRequestResponse(this, response);
+  }
+
+  virtual void OnErrorResponse(StunMessage* response) {
+    connection_->OnConnectionRequestErrorResponse(this, response);
+  }
+
+  virtual void OnTimeout() {
+    connection_->OnConnectionRequestTimeout(this);
+  }
+
+  virtual int GetNextDelay() {
+    // Each request is sent only once.  After a single delay , the request will
+    // time out.
+    timeout_ = true;
+    return CONNECTION_RESPONSE_TIMEOUT;
+  }
+
+ private:
+  Connection* connection_;
+};
+
+//
+// Connection
+//
+
+Connection::Connection(Port* port, size_t index,
+                       const Candidate& remote_candidate)
+  : port_(port), local_candidate_index_(index),
+    remote_candidate_(remote_candidate), read_state_(STATE_READ_INIT),
+    write_state_(STATE_WRITE_INIT), connected_(true), pruned_(false),
+    use_candidate_attr_(false), remote_ice_mode_(ICEMODE_FULL),
+    requests_(port->thread()), rtt_(DEFAULT_RTT), last_ping_sent_(0),
+    last_ping_received_(0), last_data_received_(0),
+    last_ping_response_received_(0), reported_(false), state_(STATE_WAITING) {
+  // All of our connections start in WAITING state.
+  // TODO(mallinath) - Start connections from STATE_FROZEN.
+  // Wire up to send stun packets
+  requests_.SignalSendPacket.connect(this, &Connection::OnSendStunPacket);
+  LOG_J(LS_INFO, this) << "Connection created";
+}
+
+Connection::~Connection() {
+}
+
+const Candidate& Connection::local_candidate() const {
+  ASSERT(local_candidate_index_ < port_->Candidates().size());
+  return port_->Candidates()[local_candidate_index_];
+}
+
+uint64 Connection::priority() const {
+  uint64 priority = 0;
+  // RFC 5245 - 5.7.2.  Computing Pair Priority and Ordering Pairs
+  // Let G be the priority for the candidate provided by the controlling
+  // agent.  Let D be the priority for the candidate provided by the
+  // controlled agent.
+  // pair priority = 2^32*MIN(G,D) + 2*MAX(G,D) + (G>D?1:0)
+  IceRole role = port_->GetIceRole();
+  if (role != ICEROLE_UNKNOWN) {
+    uint32 g = 0;
+    uint32 d = 0;
+    if (role == ICEROLE_CONTROLLING) {
+      g = local_candidate().priority();
+      d = remote_candidate_.priority();
+    } else {
+      g = remote_candidate_.priority();
+      d = local_candidate().priority();
+    }
+    priority = rtc::_min(g, d);
+    priority = priority << 32;
+    priority += 2 * rtc::_max(g, d) + (g > d ? 1 : 0);
+  }
+  return priority;
+}
+
+void Connection::set_read_state(ReadState value) {
+  ReadState old_value = read_state_;
+  read_state_ = value;
+  if (value != old_value) {
+    LOG_J(LS_VERBOSE, this) << "set_read_state";
+    SignalStateChange(this);
+    CheckTimeout();
+  }
+}
+
+void Connection::set_write_state(WriteState value) {
+  WriteState old_value = write_state_;
+  write_state_ = value;
+  if (value != old_value) {
+    LOG_J(LS_VERBOSE, this) << "set_write_state";
+    SignalStateChange(this);
+    CheckTimeout();
+  }
+}
+
+void Connection::set_state(State state) {
+  State old_state = state_;
+  state_ = state;
+  if (state != old_state) {
+    LOG_J(LS_VERBOSE, this) << "set_state";
+  }
+}
+
+void Connection::set_connected(bool value) {
+  bool old_value = connected_;
+  connected_ = value;
+  if (value != old_value) {
+    LOG_J(LS_VERBOSE, this) << "set_connected";
+  }
+}
+
+void Connection::set_use_candidate_attr(bool enable) {
+  use_candidate_attr_ = enable;
+}
+
+void Connection::OnSendStunPacket(const void* data, size_t size,
+                                  StunRequest* req) {
+  rtc::PacketOptions options(port_->DefaultDscpValue());
+  if (port_->SendTo(data, size, remote_candidate_.address(),
+                    options, false) < 0) {
+    LOG_J(LS_WARNING, this) << "Failed to send STUN ping " << req->id();
+  }
+}
+
+void Connection::OnReadPacket(
+  const char* data, size_t size, const rtc::PacketTime& packet_time) {
+  rtc::scoped_ptr<IceMessage> msg;
+  std::string remote_ufrag;
+  const rtc::SocketAddress& addr(remote_candidate_.address());
+  if (!port_->GetStunMessage(data, size, addr, msg.accept(), &remote_ufrag)) {
+    // The packet did not parse as a valid STUN message
+
+    // If this connection is readable, then pass along the packet.
+    if (read_state_ == STATE_READABLE) {
+      // readable means data from this address is acceptable
+      // Send it on!
+
+      last_data_received_ = rtc::Time();
+      recv_rate_tracker_.Update(size);
+      SignalReadPacket(this, data, size, packet_time);
+
+      // If timed out sending writability checks, start up again
+      if (!pruned_ && (write_state_ == STATE_WRITE_TIMEOUT)) {
+        LOG(LS_WARNING) << "Received a data packet on a timed-out Connection. "
+                        << "Resetting state to STATE_WRITE_INIT.";
+        set_write_state(STATE_WRITE_INIT);
+      }
+    } else {
+      // Not readable means the remote address hasn't sent a valid
+      // binding request yet.
+
+      LOG_J(LS_WARNING, this)
+        << "Received non-STUN packet from an unreadable connection.";
+    }
+  } else if (!msg) {
+    // The packet was STUN, but failed a check and was handled internally.
+  } else {
+    // The packet is STUN and passed the Port checks.
+    // Perform our own checks to ensure this packet is valid.
+    // If this is a STUN request, then update the readable bit and respond.
+    // If this is a STUN response, then update the writable bit.
+    switch (msg->type()) {
+      case STUN_BINDING_REQUEST:
+        if (remote_ufrag == remote_candidate_.username()) {
+          // Check for role conflicts.
+          if (port_->IsStandardIce() &&
+              !port_->MaybeIceRoleConflict(addr, msg.get(), remote_ufrag)) {
+            // Received conflicting role from the peer.
+            LOG(LS_INFO) << "Received conflicting role from the peer.";
+            return;
+          }
+
+          // Incoming, validated stun request from remote peer.
+          // This call will also set the connection readable.
+          port_->SendBindingResponse(msg.get(), addr);
+
+          // If timed out sending writability checks, start up again
+          if (!pruned_ && (write_state_ == STATE_WRITE_TIMEOUT))
+            set_write_state(STATE_WRITE_INIT);
+
+          if ((port_->IsStandardIce()) &&
+              (port_->GetIceRole() == ICEROLE_CONTROLLED)) {
+            const StunByteStringAttribute* use_candidate_attr =
+                msg->GetByteString(STUN_ATTR_USE_CANDIDATE);
+            if (use_candidate_attr)
+              SignalUseCandidate(this);
+          }
+        } else {
+          // The packet had the right local username, but the remote username
+          // was not the right one for the remote address.
+          LOG_J(LS_ERROR, this)
+            << "Received STUN request with bad remote username "
+            << remote_ufrag;
+          port_->SendBindingErrorResponse(msg.get(), addr,
+                                          STUN_ERROR_UNAUTHORIZED,
+                                          STUN_ERROR_REASON_UNAUTHORIZED);
+
+        }
+        break;
+
+      // Response from remote peer. Does it match request sent?
+      // This doesn't just check, it makes callbacks if transaction
+      // id's match.
+      case STUN_BINDING_RESPONSE:
+      case STUN_BINDING_ERROR_RESPONSE:
+        if (port_->IsGoogleIce() ||
+            msg->ValidateMessageIntegrity(
+                data, size, remote_candidate().password())) {
+          requests_.CheckResponse(msg.get());
+        }
+        // Otherwise silently discard the response message.
+        break;
+
+      // Remote end point sent an STUN indication instead of regular
+      // binding request. In this case |last_ping_received_| will be updated.
+      // Otherwise we can mark connection to read timeout. No response will be
+      // sent in this scenario.
+      case STUN_BINDING_INDICATION:
+        if (port_->IsStandardIce() && read_state_ == STATE_READABLE) {
+          ReceivedPing();
+        } else {
+          LOG_J(LS_WARNING, this) << "Received STUN binding indication "
+                                  << "from an unreadable connection.";
+        }
+        break;
+
+      default:
+        ASSERT(false);
+        break;
+    }
+  }
+}
+
+void Connection::OnReadyToSend() {
+  if (write_state_ == STATE_WRITABLE) {
+    SignalReadyToSend(this);
+  }
+}
+
+void Connection::Prune() {
+  if (!pruned_) {
+    LOG_J(LS_VERBOSE, this) << "Connection pruned";
+    pruned_ = true;
+    requests_.Clear();
+    set_write_state(STATE_WRITE_TIMEOUT);
+  }
+}
+
+void Connection::Destroy() {
+  LOG_J(LS_VERBOSE, this) << "Connection destroyed";
+  set_read_state(STATE_READ_TIMEOUT);
+  set_write_state(STATE_WRITE_TIMEOUT);
+}
+
+void Connection::UpdateState(uint32 now) {
+  uint32 rtt = ConservativeRTTEstimate(rtt_);
+
+  std::string pings;
+  for (size_t i = 0; i < pings_since_last_response_.size(); ++i) {
+    char buf[32];
+    rtc::sprintfn(buf, sizeof(buf), "%u",
+        pings_since_last_response_[i]);
+    pings.append(buf).append(" ");
+  }
+  LOG_J(LS_VERBOSE, this) << "UpdateState(): pings_since_last_response_=" <<
+      pings << ", rtt=" << rtt << ", now=" << now;
+
+  // Check the readable state.
+  //
+  // Since we don't know how many pings the other side has attempted, the best
+  // test we can do is a simple window.
+  // If other side has not sent ping after connection has become readable, use
+  // |last_data_received_| as the indication.
+  // If remote endpoint is doing RFC 5245, it's not required to send ping
+  // after connection is established. If this connection is serving a data
+  // channel, it may not be in a position to send media continuously. Do not
+  // mark connection timeout if it's in RFC5245 mode.
+  // Below check will be performed with end point if it's doing google-ice.
+  if (port_->IsGoogleIce() && (read_state_ == STATE_READABLE) &&
+      (last_ping_received_ + CONNECTION_READ_TIMEOUT <= now) &&
+      (last_data_received_ + CONNECTION_READ_TIMEOUT <= now)) {
+    LOG_J(LS_INFO, this) << "Unreadable after "
+                         << now - last_ping_received_
+                         << " ms without a ping,"
+                         << " ms since last received response="
+                         << now - last_ping_response_received_
+                         << " ms since last received data="
+                         << now - last_data_received_
+                         << " rtt=" << rtt;
+    set_read_state(STATE_READ_TIMEOUT);
+  }
+
+  // Check the writable state.  (The order of these checks is important.)
+  //
+  // Before becoming unwritable, we allow for a fixed number of pings to fail
+  // (i.e., receive no response).  We also have to give the response time to
+  // get back, so we include a conservative estimate of this.
+  //
+  // Before timing out writability, we give a fixed amount of time.  This is to
+  // allow for changes in network conditions.
+
+  if ((write_state_ == STATE_WRITABLE) &&
+      TooManyFailures(pings_since_last_response_,
+                      CONNECTION_WRITE_CONNECT_FAILURES,
+                      rtt,
+                      now) &&
+      TooLongWithoutResponse(pings_since_last_response_,
+                             CONNECTION_WRITE_CONNECT_TIMEOUT,
+                             now)) {
+    uint32 max_pings = CONNECTION_WRITE_CONNECT_FAILURES;
+    LOG_J(LS_INFO, this) << "Unwritable after " << max_pings
+                         << " ping failures and "
+                         << now - pings_since_last_response_[0]
+                         << " ms without a response,"
+                         << " ms since last received ping="
+                         << now - last_ping_received_
+                         << " ms since last received data="
+                         << now - last_data_received_
+                         << " rtt=" << rtt;
+    set_write_state(STATE_WRITE_UNRELIABLE);
+  }
+
+  if ((write_state_ == STATE_WRITE_UNRELIABLE ||
+       write_state_ == STATE_WRITE_INIT) &&
+      TooLongWithoutResponse(pings_since_last_response_,
+                             CONNECTION_WRITE_TIMEOUT,
+                             now)) {
+    LOG_J(LS_INFO, this) << "Timed out after "
+                         << now - pings_since_last_response_[0]
+                         << " ms without a response, rtt=" << rtt;
+    set_write_state(STATE_WRITE_TIMEOUT);
+  }
+}
+
+void Connection::Ping(uint32 now) {
+  ASSERT(connected_);
+  last_ping_sent_ = now;
+  pings_since_last_response_.push_back(now);
+  ConnectionRequest *req = new ConnectionRequest(this);
+  LOG_J(LS_VERBOSE, this) << "Sending STUN ping " << req->id() << " at " << now;
+  requests_.Send(req);
+  state_ = STATE_INPROGRESS;
+}
+
+void Connection::ReceivedPing() {
+  last_ping_received_ = rtc::Time();
+  set_read_state(STATE_READABLE);
+}
+
+std::string Connection::ToString() const {
+  const char CONNECT_STATE_ABBREV[2] = {
+    '-',  // not connected (false)
+    'C',  // connected (true)
+  };
+  const char READ_STATE_ABBREV[3] = {
+    '-',  // STATE_READ_INIT
+    'R',  // STATE_READABLE
+    'x',  // STATE_READ_TIMEOUT
+  };
+  const char WRITE_STATE_ABBREV[4] = {
+    'W',  // STATE_WRITABLE
+    'w',  // STATE_WRITE_UNRELIABLE
+    '-',  // STATE_WRITE_INIT
+    'x',  // STATE_WRITE_TIMEOUT
+  };
+  const std::string ICESTATE[4] = {
+    "W",  // STATE_WAITING
+    "I",  // STATE_INPROGRESS
+    "S",  // STATE_SUCCEEDED
+    "F"   // STATE_FAILED
+  };
+  const Candidate& local = local_candidate();
+  const Candidate& remote = remote_candidate();
+  std::stringstream ss;
+  ss << "Conn[" << port_->content_name()
+     << ":" << local.id() << ":" << local.component()
+     << ":" << local.generation()
+     << ":" << local.type() << ":" << local.protocol()
+     << ":" << local.address().ToSensitiveString()
+     << "->" << remote.id() << ":" << remote.component()
+     << ":" << remote.priority()
+     << ":" << remote.type() << ":"
+     << remote.protocol() << ":" << remote.address().ToSensitiveString() << "|"
+     << CONNECT_STATE_ABBREV[connected()]
+     << READ_STATE_ABBREV[read_state()]
+     << WRITE_STATE_ABBREV[write_state()]
+     << ICESTATE[state()] << "|"
+     << priority() << "|";
+  if (rtt_ < DEFAULT_RTT) {
+    ss << rtt_ << "]";
+  } else {
+    ss << "-]";
+  }
+  return ss.str();
+}
+
+std::string Connection::ToSensitiveString() const {
+  return ToString();
+}
+
+void Connection::OnConnectionRequestResponse(ConnectionRequest* request,
+                                             StunMessage* response) {
+  // We've already validated that this is a STUN binding response with
+  // the correct local and remote username for this connection.
+  // So if we're not already, become writable. We may be bringing a pruned
+  // connection back to life, but if we don't really want it, we can always
+  // prune it again.
+  uint32 rtt = request->Elapsed();
+  set_write_state(STATE_WRITABLE);
+  set_state(STATE_SUCCEEDED);
+
+  if (remote_ice_mode_ == ICEMODE_LITE) {
+    // A ice-lite end point never initiates ping requests. This will allow
+    // us to move to STATE_READABLE.
+    ReceivedPing();
+  }
+
+  std::string pings;
+  for (size_t i = 0; i < pings_since_last_response_.size(); ++i) {
+    char buf[32];
+    rtc::sprintfn(buf, sizeof(buf), "%u",
+        pings_since_last_response_[i]);
+    pings.append(buf).append(" ");
+  }
+
+  rtc::LoggingSeverity level =
+      (pings_since_last_response_.size() > CONNECTION_WRITE_CONNECT_FAILURES) ?
+          rtc::LS_INFO : rtc::LS_VERBOSE;
+
+  LOG_JV(level, this) << "Received STUN ping response " << request->id()
+                      << ", pings_since_last_response_=" << pings
+                      << ", rtt=" << rtt;
+
+  pings_since_last_response_.clear();
+  last_ping_response_received_ = rtc::Time();
+  rtt_ = (RTT_RATIO * rtt_ + rtt) / (RTT_RATIO + 1);
+
+  // Peer reflexive candidate is only for RFC 5245 ICE.
+  if (port_->IsStandardIce()) {
+    MaybeAddPrflxCandidate(request, response);
+  }
+}
+
+void Connection::OnConnectionRequestErrorResponse(ConnectionRequest* request,
+                                                  StunMessage* response) {
+  const StunErrorCodeAttribute* error_attr = response->GetErrorCode();
+  int error_code = STUN_ERROR_GLOBAL_FAILURE;
+  if (error_attr) {
+    if (port_->IsGoogleIce()) {
+      // When doing GICE, the error code is written out incorrectly, so we need
+      // to unmunge it here.
+      error_code = error_attr->eclass() * 256 + error_attr->number();
+    } else {
+      error_code = error_attr->code();
+    }
+  }
+
+  if (error_code == STUN_ERROR_UNKNOWN_ATTRIBUTE ||
+      error_code == STUN_ERROR_SERVER_ERROR ||
+      error_code == STUN_ERROR_UNAUTHORIZED) {
+    // Recoverable error, retry
+  } else if (error_code == STUN_ERROR_STALE_CREDENTIALS) {
+    // Race failure, retry
+  } else if (error_code == STUN_ERROR_ROLE_CONFLICT) {
+    HandleRoleConflictFromPeer();
+  } else {
+    // This is not a valid connection.
+    LOG_J(LS_ERROR, this) << "Received STUN error response, code="
+                          << error_code << "; killing connection";
+    set_state(STATE_FAILED);
+    set_write_state(STATE_WRITE_TIMEOUT);
+  }
+}
+
+void Connection::OnConnectionRequestTimeout(ConnectionRequest* request) {
+  // Log at LS_INFO if we miss a ping on a writable connection.
+  rtc::LoggingSeverity sev = (write_state_ == STATE_WRITABLE) ?
+      rtc::LS_INFO : rtc::LS_VERBOSE;
+  LOG_JV(sev, this) << "Timing-out STUN ping " << request->id()
+                    << " after " << request->Elapsed() << " ms";
+}
+
+void Connection::CheckTimeout() {
+  // If both read and write have timed out or read has never initialized, then
+  // this connection can contribute no more to p2p socket unless at some later
+  // date readability were to come back.  However, we gave readability a long
+  // time to timeout, so at this point, it seems fair to get rid of this
+  // connection.
+  if ((read_state_ == STATE_READ_TIMEOUT ||
+       read_state_ == STATE_READ_INIT) &&
+      write_state_ == STATE_WRITE_TIMEOUT) {
+    port_->thread()->Post(this, MSG_DELETE);
+  }
+}
+
+void Connection::HandleRoleConflictFromPeer() {
+  port_->SignalRoleConflict(port_);
+}
+
+void Connection::OnMessage(rtc::Message *pmsg) {
+  ASSERT(pmsg->message_id == MSG_DELETE);
+
+  LOG_J(LS_INFO, this) << "Connection deleted";
+  SignalDestroyed(this);
+  delete this;
+}
+
+size_t Connection::recv_bytes_second() {
+  return recv_rate_tracker_.units_second();
+}
+
+size_t Connection::recv_total_bytes() {
+  return recv_rate_tracker_.total_units();
+}
+
+size_t Connection::sent_bytes_second() {
+  return send_rate_tracker_.units_second();
+}
+
+size_t Connection::sent_total_bytes() {
+  return send_rate_tracker_.total_units();
+}
+
+void Connection::MaybeAddPrflxCandidate(ConnectionRequest* request,
+                                        StunMessage* response) {
+  // RFC 5245
+  // The agent checks the mapped address from the STUN response.  If the
+  // transport address does not match any of the local candidates that the
+  // agent knows about, the mapped address represents a new candidate -- a
+  // peer reflexive candidate.
+  const StunAddressAttribute* addr =
+      response->GetAddress(STUN_ATTR_XOR_MAPPED_ADDRESS);
+  if (!addr) {
+    LOG(LS_WARNING) << "Connection::OnConnectionRequestResponse - "
+                    << "No MAPPED-ADDRESS or XOR-MAPPED-ADDRESS found in the "
+                    << "stun response message";
+    return;
+  }
+
+  bool known_addr = false;
+  for (size_t i = 0; i < port_->Candidates().size(); ++i) {
+    if (port_->Candidates()[i].address() == addr->GetAddress()) {
+      known_addr = true;
+      break;
+    }
+  }
+  if (known_addr) {
+    return;
+  }
+
+  // RFC 5245
+  // Its priority is set equal to the value of the PRIORITY attribute
+  // in the Binding request.
+  const StunUInt32Attribute* priority_attr =
+      request->msg()->GetUInt32(STUN_ATTR_PRIORITY);
+  if (!priority_attr) {
+    LOG(LS_WARNING) << "Connection::OnConnectionRequestResponse - "
+                    << "No STUN_ATTR_PRIORITY found in the "
+                    << "stun response message";
+    return;
+  }
+  const uint32 priority = priority_attr->value();
+  std::string id = rtc::CreateRandomString(8);
+
+  Candidate new_local_candidate;
+  new_local_candidate.set_id(id);
+  new_local_candidate.set_component(local_candidate().component());
+  new_local_candidate.set_type(PRFLX_PORT_TYPE);
+  new_local_candidate.set_protocol(local_candidate().protocol());
+  new_local_candidate.set_address(addr->GetAddress());
+  new_local_candidate.set_priority(priority);
+  new_local_candidate.set_username(local_candidate().username());
+  new_local_candidate.set_password(local_candidate().password());
+  new_local_candidate.set_network_name(local_candidate().network_name());
+  new_local_candidate.set_related_address(local_candidate().address());
+  new_local_candidate.set_foundation(
+      ComputeFoundation(PRFLX_PORT_TYPE, local_candidate().protocol(),
+                        local_candidate().address()));
+
+  // Change the local candidate of this Connection to the new prflx candidate.
+  local_candidate_index_ = port_->AddPrflxCandidate(new_local_candidate);
+
+  // SignalStateChange to force a re-sort in P2PTransportChannel as this
+  // Connection's local candidate has changed.
+  SignalStateChange(this);
+}
+
+ProxyConnection::ProxyConnection(Port* port, size_t index,
+                                 const Candidate& candidate)
+  : Connection(port, index, candidate), error_(0) {
+}
+
+int ProxyConnection::Send(const void* data, size_t size,
+                          const rtc::PacketOptions& options) {
+  if (write_state_ == STATE_WRITE_INIT || write_state_ == STATE_WRITE_TIMEOUT) {
+    error_ = EWOULDBLOCK;
+    return SOCKET_ERROR;
+  }
+  int sent = port_->SendTo(data, size, remote_candidate_.address(),
+                           options, true);
+  if (sent <= 0) {
+    ASSERT(sent < 0);
+    error_ = port_->GetError();
+  } else {
+    send_rate_tracker_.Update(sent);
+  }
+  return sent;
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/port.h b/webrtc/p2p/base/port.h
new file mode 100644
index 0000000..48b8530
--- /dev/null
+++ b/webrtc/p2p/base/port.h
@@ -0,0 +1,602 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_PORT_H_
+#define WEBRTC_P2P_BASE_PORT_H_
+
+#include <map>
+#include <set>
+#include <string>
+#include <vector>
+
+#include "webrtc/p2p/base/candidate.h"
+#include "webrtc/p2p/base/packetsocketfactory.h"
+#include "webrtc/p2p/base/portinterface.h"
+#include "webrtc/p2p/base/stun.h"
+#include "webrtc/p2p/base/stunrequest.h"
+#include "webrtc/p2p/base/transport.h"
+#include "webrtc/base/asyncpacketsocket.h"
+#include "webrtc/base/network.h"
+#include "webrtc/base/proxyinfo.h"
+#include "webrtc/base/ratetracker.h"
+#include "webrtc/base/sigslot.h"
+#include "webrtc/base/socketaddress.h"
+#include "webrtc/base/thread.h"
+
+namespace cricket {
+
+class Connection;
+class ConnectionRequest;
+
+extern const char LOCAL_PORT_TYPE[];
+extern const char STUN_PORT_TYPE[];
+extern const char PRFLX_PORT_TYPE[];
+extern const char RELAY_PORT_TYPE[];
+
+extern const char UDP_PROTOCOL_NAME[];
+extern const char TCP_PROTOCOL_NAME[];
+extern const char SSLTCP_PROTOCOL_NAME[];
+
+// RFC 6544, TCP candidate encoding rules.
+extern const int DISCARD_PORT;
+extern const char TCPTYPE_ACTIVE_STR[];
+extern const char TCPTYPE_PASSIVE_STR[];
+extern const char TCPTYPE_SIMOPEN_STR[];
+
+// The length of time we wait before timing out readability on a connection.
+const uint32 CONNECTION_READ_TIMEOUT = 30 * 1000;   // 30 seconds
+
+// The length of time we wait before timing out writability on a connection.
+const uint32 CONNECTION_WRITE_TIMEOUT = 15 * 1000;  // 15 seconds
+
+// The length of time we wait before we become unwritable.
+const uint32 CONNECTION_WRITE_CONNECT_TIMEOUT = 5 * 1000;  // 5 seconds
+
+// The number of pings that must fail to respond before we become unwritable.
+const uint32 CONNECTION_WRITE_CONNECT_FAILURES = 5;
+
+// This is the length of time that we wait for a ping response to come back.
+const int CONNECTION_RESPONSE_TIMEOUT = 5 * 1000;   // 5 seconds
+
+enum RelayType {
+  RELAY_GTURN,   // Legacy google relay service.
+  RELAY_TURN     // Standard (TURN) relay service.
+};
+
+enum IcePriorityValue {
+  // The reason we are choosing Relay preference 2 is because, we can run
+  // Relay from client to server on UDP/TCP/TLS. To distinguish the transport
+  // protocol, we prefer UDP over TCP over TLS.
+  // For UDP ICE_TYPE_PREFERENCE_RELAY will be 2.
+  // For TCP ICE_TYPE_PREFERENCE_RELAY will be 1.
+  // For TLS ICE_TYPE_PREFERENCE_RELAY will be 0.
+  // Check turnport.cc for setting these values.
+  ICE_TYPE_PREFERENCE_RELAY = 2,
+  ICE_TYPE_PREFERENCE_HOST_TCP = 90,
+  ICE_TYPE_PREFERENCE_SRFLX = 100,
+  ICE_TYPE_PREFERENCE_PRFLX = 110,
+  ICE_TYPE_PREFERENCE_HOST = 126
+};
+
+const char* ProtoToString(ProtocolType proto);
+bool StringToProto(const char* value, ProtocolType* proto);
+
+struct ProtocolAddress {
+  rtc::SocketAddress address;
+  ProtocolType proto;
+  bool secure;
+
+  ProtocolAddress(const rtc::SocketAddress& a, ProtocolType p)
+      : address(a), proto(p), secure(false) { }
+  ProtocolAddress(const rtc::SocketAddress& a, ProtocolType p, bool sec)
+      : address(a), proto(p), secure(sec) { }
+};
+
+typedef std::set<rtc::SocketAddress> ServerAddresses;
+
+// Represents a local communication mechanism that can be used to create
+// connections to similar mechanisms of the other client.  Subclasses of this
+// one add support for specific mechanisms like local UDP ports.
+class Port : public PortInterface, public rtc::MessageHandler,
+             public sigslot::has_slots<> {
+ public:
+  Port(rtc::Thread* thread, rtc::PacketSocketFactory* factory,
+       rtc::Network* network, const rtc::IPAddress& ip,
+       const std::string& username_fragment, const std::string& password);
+  Port(rtc::Thread* thread, const std::string& type,
+       rtc::PacketSocketFactory* factory,
+       rtc::Network* network, const rtc::IPAddress& ip,
+       int min_port, int max_port, const std::string& username_fragment,
+       const std::string& password);
+  virtual ~Port();
+
+  virtual const std::string& Type() const { return type_; }
+  virtual rtc::Network* Network() const { return network_; }
+
+  // This method will set the flag which enables standard ICE/STUN procedures
+  // in STUN connectivity checks. Currently this method does
+  // 1. Add / Verify MI attribute in STUN binding requests.
+  // 2. Username attribute in STUN binding request will be RFRAF:LFRAG,
+  // as opposed to RFRAGLFRAG.
+  virtual void SetIceProtocolType(IceProtocolType protocol) {
+    ice_protocol_ = protocol;
+  }
+  virtual IceProtocolType IceProtocol() const { return ice_protocol_; }
+
+  // Methods to set/get ICE role and tiebreaker values.
+  IceRole GetIceRole() const { return ice_role_; }
+  void SetIceRole(IceRole role) { ice_role_ = role; }
+
+  void SetIceTiebreaker(uint64 tiebreaker) { tiebreaker_ = tiebreaker; }
+  uint64 IceTiebreaker() const { return tiebreaker_; }
+
+  virtual bool SharedSocket() const { return shared_socket_; }
+  void ResetSharedSocket() { shared_socket_ = false; }
+
+  // The thread on which this port performs its I/O.
+  rtc::Thread* thread() { return thread_; }
+
+  // The factory used to create the sockets of this port.
+  rtc::PacketSocketFactory* socket_factory() const { return factory_; }
+  void set_socket_factory(rtc::PacketSocketFactory* factory) {
+    factory_ = factory;
+  }
+
+  // For debugging purposes.
+  const std::string& content_name() const { return content_name_; }
+  void set_content_name(const std::string& content_name) {
+    content_name_ = content_name;
+  }
+
+  int component() const { return component_; }
+  void set_component(int component) { component_ = component; }
+
+  bool send_retransmit_count_attribute() const {
+    return send_retransmit_count_attribute_;
+  }
+  void set_send_retransmit_count_attribute(bool enable) {
+    send_retransmit_count_attribute_ = enable;
+  }
+
+  // Identifies the generation that this port was created in.
+  uint32 generation() { return generation_; }
+  void set_generation(uint32 generation) { generation_ = generation; }
+
+  // ICE requires a single username/password per content/media line. So the
+  // |ice_username_fragment_| of the ports that belongs to the same content will
+  // be the same. However this causes a small complication with our relay
+  // server, which expects different username for RTP and RTCP.
+  //
+  // To resolve this problem, we implemented the username_fragment(),
+  // which returns a different username (calculated from
+  // |ice_username_fragment_|) for RTCP in the case of ICEPROTO_GOOGLE. And the
+  // username_fragment() simply returns |ice_username_fragment_| when running
+  // in ICEPROTO_RFC5245.
+  //
+  // As a result the ICEPROTO_GOOGLE will use different usernames for RTP and
+  // RTCP. And the ICEPROTO_RFC5245 will use same username for both RTP and
+  // RTCP.
+  const std::string username_fragment() const;
+  const std::string& password() const { return password_; }
+
+  // Fired when candidates are discovered by the port. When all candidates
+  // are discovered that belong to port SignalAddressReady is fired.
+  sigslot::signal2<Port*, const Candidate&> SignalCandidateReady;
+
+  // Provides all of the above information in one handy object.
+  virtual const std::vector<Candidate>& Candidates() const {
+    return candidates_;
+  }
+
+  // SignalPortComplete is sent when port completes the task of candidates
+  // allocation.
+  sigslot::signal1<Port*> SignalPortComplete;
+  // This signal sent when port fails to allocate candidates and this port
+  // can't be used in establishing the connections. When port is in shared mode
+  // and port fails to allocate one of the candidates, port shouldn't send
+  // this signal as other candidates might be usefull in establishing the
+  // connection.
+  sigslot::signal1<Port*> SignalPortError;
+
+  // Returns a map containing all of the connections of this port, keyed by the
+  // remote address.
+  typedef std::map<rtc::SocketAddress, Connection*> AddressMap;
+  const AddressMap& connections() { return connections_; }
+
+  // Returns the connection to the given address or NULL if none exists.
+  virtual Connection* GetConnection(
+      const rtc::SocketAddress& remote_addr);
+
+  // Called each time a connection is created.
+  sigslot::signal2<Port*, Connection*> SignalConnectionCreated;
+
+  // In a shared socket mode each port which shares the socket will decide
+  // to accept the packet based on the |remote_addr|. Currently only UDP
+  // port implemented this method.
+  // TODO(mallinath) - Make it pure virtual.
+  virtual bool HandleIncomingPacket(
+      rtc::AsyncPacketSocket* socket, const char* data, size_t size,
+      const rtc::SocketAddress& remote_addr,
+      const rtc::PacketTime& packet_time) {
+    ASSERT(false);
+    return false;
+  }
+
+  // Sends a response message (normal or error) to the given request.  One of
+  // these methods should be called as a response to SignalUnknownAddress.
+  // NOTE: You MUST call CreateConnection BEFORE SendBindingResponse.
+  virtual void SendBindingResponse(StunMessage* request,
+                                   const rtc::SocketAddress& addr);
+  virtual void SendBindingErrorResponse(
+      StunMessage* request, const rtc::SocketAddress& addr,
+      int error_code, const std::string& reason);
+
+  void set_proxy(const std::string& user_agent,
+                 const rtc::ProxyInfo& proxy) {
+    user_agent_ = user_agent;
+    proxy_ = proxy;
+  }
+  const std::string& user_agent() { return user_agent_; }
+  const rtc::ProxyInfo& proxy() { return proxy_; }
+
+  virtual void EnablePortPackets();
+
+  // Called if the port has no connections and is no longer useful.
+  void Destroy();
+
+  virtual void OnMessage(rtc::Message *pmsg);
+
+  // Debugging description of this port
+  virtual std::string ToString() const;
+  rtc::IPAddress& ip() { return ip_; }
+  int min_port() { return min_port_; }
+  int max_port() { return max_port_; }
+
+  // Timeout shortening function to speed up unit tests.
+  void set_timeout_delay(int delay) { timeout_delay_ = delay; }
+
+  // This method will return local and remote username fragements from the
+  // stun username attribute if present.
+  bool ParseStunUsername(const StunMessage* stun_msg,
+                         std::string* local_username,
+                         std::string* remote_username,
+                         IceProtocolType* remote_protocol_type) const;
+  void CreateStunUsername(const std::string& remote_username,
+                          std::string* stun_username_attr_str) const;
+
+  bool MaybeIceRoleConflict(const rtc::SocketAddress& addr,
+                            IceMessage* stun_msg,
+                            const std::string& remote_ufrag);
+
+  // Called when the socket is currently able to send.
+  void OnReadyToSend();
+
+  // Called when the Connection discovers a local peer reflexive candidate.
+  // Returns the index of the new local candidate.
+  size_t AddPrflxCandidate(const Candidate& local);
+
+  // Returns if RFC 5245 ICE protocol is used.
+  bool IsStandardIce() const;
+
+  // Returns if Google ICE protocol is used.
+  bool IsGoogleIce() const;
+
+  // Returns if Hybrid ICE protocol is used.
+  bool IsHybridIce() const;
+
+  void set_candidate_filter(uint32 candidate_filter) {
+    candidate_filter_ = candidate_filter;
+  }
+
+ protected:
+  enum {
+    MSG_CHECKTIMEOUT = 0,
+    MSG_FIRST_AVAILABLE
+  };
+
+  void set_type(const std::string& type) { type_ = type; }
+
+  void AddAddress(const rtc::SocketAddress& address,
+                  const rtc::SocketAddress& base_address,
+                  const rtc::SocketAddress& related_address,
+                  const std::string& protocol, const std::string& tcptype,
+                  const std::string& type, uint32 type_preference,
+                  uint32 relay_preference, bool final);
+
+  // Adds the given connection to the list.  (Deleting removes them.)
+  void AddConnection(Connection* conn);
+
+  // Called when a packet is received from an unknown address that is not
+  // currently a connection.  If this is an authenticated STUN binding request,
+  // then we will signal the client.
+  void OnReadPacket(const char* data, size_t size,
+                    const rtc::SocketAddress& addr,
+                    ProtocolType proto);
+
+  // If the given data comprises a complete and correct STUN message then the
+  // return value is true, otherwise false. If the message username corresponds
+  // with this port's username fragment, msg will contain the parsed STUN
+  // message.  Otherwise, the function may send a STUN response internally.
+  // remote_username contains the remote fragment of the STUN username.
+  bool GetStunMessage(const char* data, size_t size,
+                      const rtc::SocketAddress& addr,
+                      IceMessage** out_msg, std::string* out_username);
+
+  // Checks if the address in addr is compatible with the port's ip.
+  bool IsCompatibleAddress(const rtc::SocketAddress& addr);
+
+  // Returns default DSCP value.
+  rtc::DiffServCodePoint DefaultDscpValue() const {
+    // No change from what MediaChannel set.
+    return rtc::DSCP_NO_CHANGE;
+  }
+
+  uint32 candidate_filter() { return candidate_filter_; }
+
+ private:
+  void Construct();
+  // Called when one of our connections deletes itself.
+  void OnConnectionDestroyed(Connection* conn);
+
+  // Checks if this port is useless, and hence, should be destroyed.
+  void CheckTimeout();
+
+  rtc::Thread* thread_;
+  rtc::PacketSocketFactory* factory_;
+  std::string type_;
+  bool send_retransmit_count_attribute_;
+  rtc::Network* network_;
+  rtc::IPAddress ip_;
+  int min_port_;
+  int max_port_;
+  std::string content_name_;
+  int component_;
+  uint32 generation_;
+  // In order to establish a connection to this Port (so that real data can be
+  // sent through), the other side must send us a STUN binding request that is
+  // authenticated with this username_fragment and password.
+  // PortAllocatorSession will provide these username_fragment and password.
+  //
+  // Note: we should always use username_fragment() instead of using
+  // |ice_username_fragment_| directly. For the details see the comment on
+  // username_fragment().
+  std::string ice_username_fragment_;
+  std::string password_;
+  std::vector<Candidate> candidates_;
+  AddressMap connections_;
+  int timeout_delay_;
+  bool enable_port_packets_;
+  IceProtocolType ice_protocol_;
+  IceRole ice_role_;
+  uint64 tiebreaker_;
+  bool shared_socket_;
+  // Information to use when going through a proxy.
+  std::string user_agent_;
+  rtc::ProxyInfo proxy_;
+
+  // Candidate filter is pushed down to Port such that each Port could
+  // make its own decision on how to create candidates. For example,
+  // when IceTransportsType is set to relay, both RelayPort and
+  // TurnPort will hide raddr to avoid local address leakage.
+  uint32 candidate_filter_;
+
+  friend class Connection;
+};
+
+// Represents a communication link between a port on the local client and a
+// port on the remote client.
+class Connection : public rtc::MessageHandler,
+    public sigslot::has_slots<> {
+ public:
+  // States are from RFC 5245. http://tools.ietf.org/html/rfc5245#section-5.7.4
+  enum State {
+    STATE_WAITING = 0,  // Check has not been performed, Waiting pair on CL.
+    STATE_INPROGRESS,   // Check has been sent, transaction is in progress.
+    STATE_SUCCEEDED,    // Check already done, produced a successful result.
+    STATE_FAILED        // Check for this connection failed.
+  };
+
+  virtual ~Connection();
+
+  // The local port where this connection sends and receives packets.
+  Port* port() { return port_; }
+  const Port* port() const { return port_; }
+
+  // Returns the description of the local port
+  virtual const Candidate& local_candidate() const;
+
+  // Returns the description of the remote port to which we communicate.
+  const Candidate& remote_candidate() const { return remote_candidate_; }
+
+  // Returns the pair priority.
+  uint64 priority() const;
+
+  enum ReadState {
+    STATE_READ_INIT    = 0,  // we have yet to receive a ping
+    STATE_READABLE     = 1,  // we have received pings recently
+    STATE_READ_TIMEOUT = 2,  // we haven't received pings in a while
+  };
+
+  ReadState read_state() const { return read_state_; }
+  bool readable() const { return read_state_ == STATE_READABLE; }
+
+  enum WriteState {
+    STATE_WRITABLE          = 0,  // we have received ping responses recently
+    STATE_WRITE_UNRELIABLE  = 1,  // we have had a few ping failures
+    STATE_WRITE_INIT        = 2,  // we have yet to receive a ping response
+    STATE_WRITE_TIMEOUT     = 3,  // we have had a large number of ping failures
+  };
+
+  WriteState write_state() const { return write_state_; }
+  bool writable() const { return write_state_ == STATE_WRITABLE; }
+
+  // Determines whether the connection has finished connecting.  This can only
+  // be false for TCP connections.
+  bool connected() const { return connected_; }
+
+  // Estimate of the round-trip time over this connection.
+  uint32 rtt() const { return rtt_; }
+
+  size_t sent_total_bytes();
+  size_t sent_bytes_second();
+  size_t recv_total_bytes();
+  size_t recv_bytes_second();
+  sigslot::signal1<Connection*> SignalStateChange;
+
+  // Sent when the connection has decided that it is no longer of value.  It
+  // will delete itself immediately after this call.
+  sigslot::signal1<Connection*> SignalDestroyed;
+
+  // The connection can send and receive packets asynchronously.  This matches
+  // the interface of AsyncPacketSocket, which may use UDP or TCP under the
+  // covers.
+  virtual int Send(const void* data, size_t size,
+                   const rtc::PacketOptions& options) = 0;
+
+  // Error if Send() returns < 0
+  virtual int GetError() = 0;
+
+  sigslot::signal4<Connection*, const char*, size_t,
+                   const rtc::PacketTime&> SignalReadPacket;
+
+  sigslot::signal1<Connection*> SignalReadyToSend;
+
+  // Called when a packet is received on this connection.
+  void OnReadPacket(const char* data, size_t size,
+                    const rtc::PacketTime& packet_time);
+
+  // Called when the socket is currently able to send.
+  void OnReadyToSend();
+
+  // Called when a connection is determined to be no longer useful to us.  We
+  // still keep it around in case the other side wants to use it.  But we can
+  // safely stop pinging on it and we can allow it to time out if the other
+  // side stops using it as well.
+  bool pruned() const { return pruned_; }
+  void Prune();
+
+  bool use_candidate_attr() const { return use_candidate_attr_; }
+  void set_use_candidate_attr(bool enable);
+
+  void set_remote_ice_mode(IceMode mode) {
+    remote_ice_mode_ = mode;
+  }
+
+  // Makes the connection go away.
+  void Destroy();
+
+  // Checks that the state of this connection is up-to-date.  The argument is
+  // the current time, which is compared against various timeouts.
+  void UpdateState(uint32 now);
+
+  // Called when this connection should try checking writability again.
+  uint32 last_ping_sent() const { return last_ping_sent_; }
+  void Ping(uint32 now);
+
+  // Called whenever a valid ping is received on this connection.  This is
+  // public because the connection intercepts the first ping for us.
+  uint32 last_ping_received() const { return last_ping_received_; }
+  void ReceivedPing();
+
+  // Debugging description of this connection
+  std::string ToString() const;
+  std::string ToSensitiveString() const;
+
+  bool reported() const { return reported_; }
+  void set_reported(bool reported) { reported_ = reported;}
+
+  // This flag will be set if this connection is the chosen one for media
+  // transmission. This connection will send STUN ping with USE-CANDIDATE
+  // attribute.
+  sigslot::signal1<Connection*> SignalUseCandidate;
+  // Invoked when Connection receives STUN error response with 487 code.
+  void HandleRoleConflictFromPeer();
+
+  State state() const { return state_; }
+
+  IceMode remote_ice_mode() const { return remote_ice_mode_; }
+
+ protected:
+  // Constructs a new connection to the given remote port.
+  Connection(Port* port, size_t index, const Candidate& candidate);
+
+  // Called back when StunRequestManager has a stun packet to send
+  void OnSendStunPacket(const void* data, size_t size, StunRequest* req);
+
+  // Callbacks from ConnectionRequest
+  void OnConnectionRequestResponse(ConnectionRequest* req,
+                                   StunMessage* response);
+  void OnConnectionRequestErrorResponse(ConnectionRequest* req,
+                                        StunMessage* response);
+  void OnConnectionRequestTimeout(ConnectionRequest* req);
+
+  // Changes the state and signals if necessary.
+  void set_read_state(ReadState value);
+  void set_write_state(WriteState value);
+  void set_state(State state);
+  void set_connected(bool value);
+
+  // Checks if this connection is useless, and hence, should be destroyed.
+  void CheckTimeout();
+
+  void OnMessage(rtc::Message *pmsg);
+
+  Port* port_;
+  size_t local_candidate_index_;
+  Candidate remote_candidate_;
+  ReadState read_state_;
+  WriteState write_state_;
+  bool connected_;
+  bool pruned_;
+  // By default |use_candidate_attr_| flag will be true,
+  // as we will be using agrressive nomination.
+  // But when peer is ice-lite, this flag "must" be initialized to false and
+  // turn on when connection becomes "best connection".
+  bool use_candidate_attr_;
+  IceMode remote_ice_mode_;
+  StunRequestManager requests_;
+  uint32 rtt_;
+  uint32 last_ping_sent_;      // last time we sent a ping to the other side
+  uint32 last_ping_received_;  // last time we received a ping from the other
+                               // side
+  uint32 last_data_received_;
+  uint32 last_ping_response_received_;
+  std::vector<uint32> pings_since_last_response_;
+
+  rtc::RateTracker recv_rate_tracker_;
+  rtc::RateTracker send_rate_tracker_;
+
+ private:
+  void MaybeAddPrflxCandidate(ConnectionRequest* request,
+                              StunMessage* response);
+
+  bool reported_;
+  State state_;
+
+  friend class Port;
+  friend class ConnectionRequest;
+};
+
+// ProxyConnection defers all the interesting work to the port
+class ProxyConnection : public Connection {
+ public:
+  ProxyConnection(Port* port, size_t index, const Candidate& candidate);
+
+  virtual int Send(const void* data, size_t size,
+                   const rtc::PacketOptions& options);
+  virtual int GetError() { return error_; }
+
+ private:
+  int error_;
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_PORT_H_
diff --git a/webrtc/p2p/base/port_unittest.cc b/webrtc/p2p/base/port_unittest.cc
new file mode 100644
index 0000000..8805709
--- /dev/null
+++ b/webrtc/p2p/base/port_unittest.cc
@@ -0,0 +1,2494 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/basicpacketsocketfactory.h"
+#include "webrtc/p2p/base/portproxy.h"
+#include "webrtc/p2p/base/relayport.h"
+#include "webrtc/p2p/base/stunport.h"
+#include "webrtc/p2p/base/tcpport.h"
+#include "webrtc/p2p/base/testrelayserver.h"
+#include "webrtc/p2p/base/teststunserver.h"
+#include "webrtc/p2p/base/testturnserver.h"
+#include "webrtc/p2p/base/transport.h"
+#include "webrtc/p2p/base/turnport.h"
+#include "webrtc/base/crc32.h"
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/helpers.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/natserver.h"
+#include "webrtc/base/natsocketfactory.h"
+#include "webrtc/base/physicalsocketserver.h"
+#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/socketaddress.h"
+#include "webrtc/base/ssladapter.h"
+#include "webrtc/base/stringutils.h"
+#include "webrtc/base/thread.h"
+#include "webrtc/base/virtualsocketserver.h"
+
+using rtc::AsyncPacketSocket;
+using rtc::ByteBuffer;
+using rtc::NATType;
+using rtc::NAT_OPEN_CONE;
+using rtc::NAT_ADDR_RESTRICTED;
+using rtc::NAT_PORT_RESTRICTED;
+using rtc::NAT_SYMMETRIC;
+using rtc::PacketSocketFactory;
+using rtc::scoped_ptr;
+using rtc::Socket;
+using rtc::SocketAddress;
+using namespace cricket;
+
+static const int kTimeout = 1000;
+static const SocketAddress kLocalAddr1("192.168.1.2", 0);
+static const SocketAddress kLocalAddr2("192.168.1.3", 0);
+static const SocketAddress kNatAddr1("77.77.77.77", rtc::NAT_SERVER_PORT);
+static const SocketAddress kNatAddr2("88.88.88.88", rtc::NAT_SERVER_PORT);
+static const SocketAddress kStunAddr("99.99.99.1", STUN_SERVER_PORT);
+static const SocketAddress kRelayUdpIntAddr("99.99.99.2", 5000);
+static const SocketAddress kRelayUdpExtAddr("99.99.99.3", 5001);
+static const SocketAddress kRelayTcpIntAddr("99.99.99.2", 5002);
+static const SocketAddress kRelayTcpExtAddr("99.99.99.3", 5003);
+static const SocketAddress kRelaySslTcpIntAddr("99.99.99.2", 5004);
+static const SocketAddress kRelaySslTcpExtAddr("99.99.99.3", 5005);
+static const SocketAddress kTurnUdpIntAddr("99.99.99.4", STUN_SERVER_PORT);
+static const SocketAddress kTurnUdpExtAddr("99.99.99.5", 0);
+static const RelayCredentials kRelayCredentials("test", "test");
+
+// TODO: Update these when RFC5245 is completely supported.
+// Magic value of 30 is from RFC3484, for IPv4 addresses.
+static const uint32 kDefaultPrflxPriority = ICE_TYPE_PREFERENCE_PRFLX << 24 |
+             30 << 8 | (256 - ICE_CANDIDATE_COMPONENT_DEFAULT);
+static const int STUN_ERROR_BAD_REQUEST_AS_GICE =
+    STUN_ERROR_BAD_REQUEST / 256 * 100 + STUN_ERROR_BAD_REQUEST % 256;
+static const int STUN_ERROR_UNAUTHORIZED_AS_GICE =
+    STUN_ERROR_UNAUTHORIZED / 256 * 100 + STUN_ERROR_UNAUTHORIZED % 256;
+static const int STUN_ERROR_SERVER_ERROR_AS_GICE =
+    STUN_ERROR_SERVER_ERROR / 256 * 100 + STUN_ERROR_SERVER_ERROR % 256;
+
+static const int kTiebreaker1 = 11111;
+static const int kTiebreaker2 = 22222;
+
+static Candidate GetCandidate(Port* port) {
+  assert(port->Candidates().size() == 1);
+  return port->Candidates()[0];
+}
+
+static SocketAddress GetAddress(Port* port) {
+  return GetCandidate(port).address();
+}
+
+static IceMessage* CopyStunMessage(const IceMessage* src) {
+  IceMessage* dst = new IceMessage();
+  ByteBuffer buf;
+  src->Write(&buf);
+  dst->Read(&buf);
+  return dst;
+}
+
+static bool WriteStunMessage(const StunMessage* msg, ByteBuffer* buf) {
+  buf->Resize(0);  // clear out any existing buffer contents
+  return msg->Write(buf);
+}
+
+// Stub port class for testing STUN generation and processing.
+class TestPort : public Port {
+ public:
+  TestPort(rtc::Thread* thread, const std::string& type,
+           rtc::PacketSocketFactory* factory, rtc::Network* network,
+           const rtc::IPAddress& ip, int min_port, int max_port,
+           const std::string& username_fragment, const std::string& password)
+      : Port(thread, type, factory, network, ip,
+             min_port, max_port, username_fragment, password) {
+  }
+  ~TestPort() {}
+
+  // Expose GetStunMessage so that we can test it.
+  using cricket::Port::GetStunMessage;
+
+  // The last StunMessage that was sent on this Port.
+  // TODO: Make these const; requires changes to SendXXXXResponse.
+  ByteBuffer* last_stun_buf() { return last_stun_buf_.get(); }
+  IceMessage* last_stun_msg() { return last_stun_msg_.get(); }
+  int last_stun_error_code() {
+    int code = 0;
+    if (last_stun_msg_) {
+      const StunErrorCodeAttribute* error_attr = last_stun_msg_->GetErrorCode();
+      if (error_attr) {
+        code = error_attr->code();
+      }
+    }
+    return code;
+  }
+
+  virtual void PrepareAddress() {
+    rtc::SocketAddress addr(ip(), min_port());
+    AddAddress(addr, addr, rtc::SocketAddress(), "udp", "", Type(),
+               ICE_TYPE_PREFERENCE_HOST, 0, true);
+  }
+
+  // Exposed for testing candidate building.
+  void AddCandidateAddress(const rtc::SocketAddress& addr) {
+    AddAddress(addr, addr, rtc::SocketAddress(), "udp", "", Type(),
+               type_preference_, 0, false);
+  }
+  void AddCandidateAddress(const rtc::SocketAddress& addr,
+                           const rtc::SocketAddress& base_address,
+                           const std::string& type,
+                           int type_preference,
+                           bool final) {
+    AddAddress(addr, base_address, rtc::SocketAddress(), "udp", "", type,
+               type_preference, 0, final);
+  }
+
+  virtual Connection* CreateConnection(const Candidate& remote_candidate,
+                                       CandidateOrigin origin) {
+    Connection* conn = new ProxyConnection(this, 0, remote_candidate);
+    AddConnection(conn);
+    // Set use-candidate attribute flag as this will add USE-CANDIDATE attribute
+    // in STUN binding requests.
+    conn->set_use_candidate_attr(true);
+    return conn;
+  }
+  virtual int SendTo(
+      const void* data, size_t size, const rtc::SocketAddress& addr,
+      const rtc::PacketOptions& options, bool payload) {
+    if (!payload) {
+      IceMessage* msg = new IceMessage;
+      ByteBuffer* buf = new ByteBuffer(static_cast<const char*>(data), size);
+      ByteBuffer::ReadPosition pos(buf->GetReadPosition());
+      if (!msg->Read(buf)) {
+        delete msg;
+        delete buf;
+        return -1;
+      }
+      buf->SetReadPosition(pos);
+      last_stun_buf_.reset(buf);
+      last_stun_msg_.reset(msg);
+    }
+    return static_cast<int>(size);
+  }
+  virtual int SetOption(rtc::Socket::Option opt, int value) {
+    return 0;
+  }
+  virtual int GetOption(rtc::Socket::Option opt, int* value) {
+    return -1;
+  }
+  virtual int GetError() {
+    return 0;
+  }
+  void Reset() {
+    last_stun_buf_.reset();
+    last_stun_msg_.reset();
+  }
+  void set_type_preference(int type_preference) {
+    type_preference_ = type_preference;
+  }
+
+ private:
+  rtc::scoped_ptr<ByteBuffer> last_stun_buf_;
+  rtc::scoped_ptr<IceMessage> last_stun_msg_;
+  int type_preference_;
+};
+
+class TestChannel : public sigslot::has_slots<> {
+ public:
+  // Takes ownership of |p1| (but not |p2|).
+  TestChannel(Port* p1, Port* p2)
+      : ice_mode_(ICEMODE_FULL), src_(p1), dst_(p2), complete_count_(0),
+	conn_(NULL), remote_request_(), nominated_(false) {
+    src_->SignalPortComplete.connect(
+        this, &TestChannel::OnPortComplete);
+    src_->SignalUnknownAddress.connect(this, &TestChannel::OnUnknownAddress);
+    src_->SignalDestroyed.connect(this, &TestChannel::OnSrcPortDestroyed);
+  }
+
+  int complete_count() { return complete_count_; }
+  Connection* conn() { return conn_; }
+  const SocketAddress& remote_address() { return remote_address_; }
+  const std::string remote_fragment() { return remote_frag_; }
+
+  void Start() {
+    src_->PrepareAddress();
+  }
+  void CreateConnection() {
+    conn_ = src_->CreateConnection(GetCandidate(dst_), Port::ORIGIN_MESSAGE);
+    IceMode remote_ice_mode =
+        (ice_mode_ == ICEMODE_FULL) ? ICEMODE_LITE : ICEMODE_FULL;
+    conn_->set_remote_ice_mode(remote_ice_mode);
+    conn_->set_use_candidate_attr(remote_ice_mode == ICEMODE_FULL);
+    conn_->SignalStateChange.connect(
+        this, &TestChannel::OnConnectionStateChange);
+  }
+  void OnConnectionStateChange(Connection* conn) {
+    if (conn->write_state() == Connection::STATE_WRITABLE) {
+      conn->set_use_candidate_attr(true);
+      nominated_ = true;
+    }
+  }
+  void AcceptConnection() {
+    ASSERT_TRUE(remote_request_.get() != NULL);
+    Candidate c = GetCandidate(dst_);
+    c.set_address(remote_address_);
+    conn_ = src_->CreateConnection(c, Port::ORIGIN_MESSAGE);
+    src_->SendBindingResponse(remote_request_.get(), remote_address_);
+    remote_request_.reset();
+  }
+  void Ping() {
+    Ping(0);
+  }
+  void Ping(uint32 now) {
+    conn_->Ping(now);
+  }
+  void Stop() {
+    conn_->SignalDestroyed.connect(this, &TestChannel::OnDestroyed);
+    conn_->Destroy();
+  }
+
+  void OnPortComplete(Port* port) {
+    complete_count_++;
+  }
+  void SetIceMode(IceMode ice_mode) {
+    ice_mode_ = ice_mode;
+  }
+
+  void OnUnknownAddress(PortInterface* port, const SocketAddress& addr,
+                        ProtocolType proto,
+                        IceMessage* msg, const std::string& rf,
+                        bool /*port_muxed*/) {
+    ASSERT_EQ(src_.get(), port);
+    if (!remote_address_.IsNil()) {
+      ASSERT_EQ(remote_address_, addr);
+    }
+    // MI and PRIORITY attribute should be present in ping requests when port
+    // is in ICEPROTO_RFC5245 mode.
+    const cricket::StunUInt32Attribute* priority_attr =
+        msg->GetUInt32(STUN_ATTR_PRIORITY);
+    const cricket::StunByteStringAttribute* mi_attr =
+        msg->GetByteString(STUN_ATTR_MESSAGE_INTEGRITY);
+    const cricket::StunUInt32Attribute* fingerprint_attr =
+        msg->GetUInt32(STUN_ATTR_FINGERPRINT);
+    if (src_->IceProtocol() == cricket::ICEPROTO_RFC5245) {
+      EXPECT_TRUE(priority_attr != NULL);
+      EXPECT_TRUE(mi_attr != NULL);
+      EXPECT_TRUE(fingerprint_attr != NULL);
+    } else {
+      EXPECT_TRUE(priority_attr == NULL);
+      EXPECT_TRUE(mi_attr == NULL);
+      EXPECT_TRUE(fingerprint_attr == NULL);
+    }
+    remote_address_ = addr;
+    remote_request_.reset(CopyStunMessage(msg));
+    remote_frag_ = rf;
+  }
+
+  void OnDestroyed(Connection* conn) {
+    ASSERT_EQ(conn_, conn);
+    conn_ = NULL;
+  }
+
+  void OnSrcPortDestroyed(PortInterface* port) {
+    Port* destroyed_src = src_.release();
+    ASSERT_EQ(destroyed_src, port);
+  }
+
+  bool nominated() const { return nominated_; }
+
+ private:
+  IceMode ice_mode_;
+  rtc::scoped_ptr<Port> src_;
+  Port* dst_;
+
+  int complete_count_;
+  Connection* conn_;
+  SocketAddress remote_address_;
+  rtc::scoped_ptr<StunMessage> remote_request_;
+  std::string remote_frag_;
+  bool nominated_;
+};
+
+class PortTest : public testing::Test, public sigslot::has_slots<> {
+ public:
+  PortTest()
+      : main_(rtc::Thread::Current()),
+        pss_(new rtc::PhysicalSocketServer),
+        ss_(new rtc::VirtualSocketServer(pss_.get())),
+        ss_scope_(ss_.get()),
+        network_("unittest", "unittest", rtc::IPAddress(INADDR_ANY), 32),
+        socket_factory_(rtc::Thread::Current()),
+        nat_factory1_(ss_.get(), kNatAddr1),
+        nat_factory2_(ss_.get(), kNatAddr2),
+        nat_socket_factory1_(&nat_factory1_),
+        nat_socket_factory2_(&nat_factory2_),
+        stun_server_(TestStunServer::Create(main_, kStunAddr)),
+        turn_server_(main_, kTurnUdpIntAddr, kTurnUdpExtAddr),
+        relay_server_(main_, kRelayUdpIntAddr, kRelayUdpExtAddr,
+                      kRelayTcpIntAddr, kRelayTcpExtAddr,
+                      kRelaySslTcpIntAddr, kRelaySslTcpExtAddr),
+        username_(rtc::CreateRandomString(ICE_UFRAG_LENGTH)),
+        password_(rtc::CreateRandomString(ICE_PWD_LENGTH)),
+        ice_protocol_(cricket::ICEPROTO_GOOGLE),
+        role_conflict_(false),
+        destroyed_(false) {
+    network_.AddIP(rtc::IPAddress(INADDR_ANY));
+  }
+
+ protected:
+  void TestLocalToLocal() {
+    Port* port1 = CreateUdpPort(kLocalAddr1);
+    Port* port2 = CreateUdpPort(kLocalAddr2);
+    TestConnectivity("udp", port1, "udp", port2, true, true, true, true);
+  }
+  void TestLocalToStun(NATType ntype) {
+    Port* port1 = CreateUdpPort(kLocalAddr1);
+    nat_server2_.reset(CreateNatServer(kNatAddr2, ntype));
+    Port* port2 = CreateStunPort(kLocalAddr2, &nat_socket_factory2_);
+    TestConnectivity("udp", port1, StunName(ntype), port2,
+                     ntype == NAT_OPEN_CONE, true,
+                     ntype != NAT_SYMMETRIC, true);
+  }
+  void TestLocalToRelay(RelayType rtype, ProtocolType proto) {
+    Port* port1 = CreateUdpPort(kLocalAddr1);
+    Port* port2 = CreateRelayPort(kLocalAddr2, rtype, proto, PROTO_UDP);
+    TestConnectivity("udp", port1, RelayName(rtype, proto), port2,
+                     rtype == RELAY_GTURN, true, true, true);
+  }
+  void TestStunToLocal(NATType ntype) {
+    nat_server1_.reset(CreateNatServer(kNatAddr1, ntype));
+    Port* port1 = CreateStunPort(kLocalAddr1, &nat_socket_factory1_);
+    Port* port2 = CreateUdpPort(kLocalAddr2);
+    TestConnectivity(StunName(ntype), port1, "udp", port2,
+                     true, ntype != NAT_SYMMETRIC, true, true);
+  }
+  void TestStunToStun(NATType ntype1, NATType ntype2) {
+    nat_server1_.reset(CreateNatServer(kNatAddr1, ntype1));
+    Port* port1 = CreateStunPort(kLocalAddr1, &nat_socket_factory1_);
+    nat_server2_.reset(CreateNatServer(kNatAddr2, ntype2));
+    Port* port2 = CreateStunPort(kLocalAddr2, &nat_socket_factory2_);
+    TestConnectivity(StunName(ntype1), port1, StunName(ntype2), port2,
+                     ntype2 == NAT_OPEN_CONE,
+                     ntype1 != NAT_SYMMETRIC, ntype2 != NAT_SYMMETRIC,
+                     ntype1 + ntype2 < (NAT_PORT_RESTRICTED + NAT_SYMMETRIC));
+  }
+  void TestStunToRelay(NATType ntype, RelayType rtype, ProtocolType proto) {
+    nat_server1_.reset(CreateNatServer(kNatAddr1, ntype));
+    Port* port1 = CreateStunPort(kLocalAddr1, &nat_socket_factory1_);
+    Port* port2 = CreateRelayPort(kLocalAddr2, rtype, proto, PROTO_UDP);
+    TestConnectivity(StunName(ntype), port1, RelayName(rtype, proto), port2,
+                     rtype == RELAY_GTURN, ntype != NAT_SYMMETRIC, true, true);
+  }
+  void TestTcpToTcp() {
+    Port* port1 = CreateTcpPort(kLocalAddr1);
+    Port* port2 = CreateTcpPort(kLocalAddr2);
+    TestConnectivity("tcp", port1, "tcp", port2, true, false, true, true);
+  }
+  void TestTcpToRelay(RelayType rtype, ProtocolType proto) {
+    Port* port1 = CreateTcpPort(kLocalAddr1);
+    Port* port2 = CreateRelayPort(kLocalAddr2, rtype, proto, PROTO_TCP);
+    TestConnectivity("tcp", port1, RelayName(rtype, proto), port2,
+                     rtype == RELAY_GTURN, false, true, true);
+  }
+  void TestSslTcpToRelay(RelayType rtype, ProtocolType proto) {
+    Port* port1 = CreateTcpPort(kLocalAddr1);
+    Port* port2 = CreateRelayPort(kLocalAddr2, rtype, proto, PROTO_SSLTCP);
+    TestConnectivity("ssltcp", port1, RelayName(rtype, proto), port2,
+                     rtype == RELAY_GTURN, false, true, true);
+  }
+
+  // helpers for above functions
+  UDPPort* CreateUdpPort(const SocketAddress& addr) {
+    return CreateUdpPort(addr, &socket_factory_);
+  }
+  UDPPort* CreateUdpPort(const SocketAddress& addr,
+                         PacketSocketFactory* socket_factory) {
+    UDPPort* port = UDPPort::Create(main_, socket_factory, &network_,
+                                    addr.ipaddr(), 0, 0, username_, password_);
+    port->SetIceProtocolType(ice_protocol_);
+    return port;
+  }
+  TCPPort* CreateTcpPort(const SocketAddress& addr) {
+    TCPPort* port = CreateTcpPort(addr, &socket_factory_);
+    port->SetIceProtocolType(ice_protocol_);
+    return port;
+  }
+  TCPPort* CreateTcpPort(const SocketAddress& addr,
+                        PacketSocketFactory* socket_factory) {
+    TCPPort* port = TCPPort::Create(main_, socket_factory, &network_,
+                                    addr.ipaddr(), 0, 0, username_, password_,
+                                    true);
+    port->SetIceProtocolType(ice_protocol_);
+    return port;
+  }
+  StunPort* CreateStunPort(const SocketAddress& addr,
+                           rtc::PacketSocketFactory* factory) {
+    ServerAddresses stun_servers;
+    stun_servers.insert(kStunAddr);
+    StunPort* port = StunPort::Create(main_, factory, &network_,
+                                      addr.ipaddr(), 0, 0,
+                                      username_, password_, stun_servers);
+    port->SetIceProtocolType(ice_protocol_);
+    return port;
+  }
+  Port* CreateRelayPort(const SocketAddress& addr, RelayType rtype,
+                        ProtocolType int_proto, ProtocolType ext_proto) {
+    if (rtype == RELAY_TURN) {
+      return CreateTurnPort(addr, &socket_factory_, int_proto, ext_proto);
+    } else {
+      return CreateGturnPort(addr, int_proto, ext_proto);
+    }
+  }
+  TurnPort* CreateTurnPort(const SocketAddress& addr,
+                           PacketSocketFactory* socket_factory,
+                           ProtocolType int_proto, ProtocolType ext_proto) {
+    return CreateTurnPort(addr, socket_factory,
+                          int_proto, ext_proto, kTurnUdpIntAddr);
+  }
+  TurnPort* CreateTurnPort(const SocketAddress& addr,
+                           PacketSocketFactory* socket_factory,
+                           ProtocolType int_proto, ProtocolType ext_proto,
+                           const rtc::SocketAddress& server_addr) {
+    TurnPort* port = TurnPort::Create(main_, socket_factory, &network_,
+                                      addr.ipaddr(), 0, 0,
+                                      username_, password_, ProtocolAddress(
+                                          server_addr, PROTO_UDP),
+                                      kRelayCredentials, 0);
+    port->SetIceProtocolType(ice_protocol_);
+    return port;
+  }
+  RelayPort* CreateGturnPort(const SocketAddress& addr,
+                             ProtocolType int_proto, ProtocolType ext_proto) {
+    RelayPort* port = CreateGturnPort(addr);
+    SocketAddress addrs[] =
+        { kRelayUdpIntAddr, kRelayTcpIntAddr, kRelaySslTcpIntAddr };
+    port->AddServerAddress(ProtocolAddress(addrs[int_proto], int_proto));
+    return port;
+  }
+  RelayPort* CreateGturnPort(const SocketAddress& addr) {
+    RelayPort* port = RelayPort::Create(main_, &socket_factory_, &network_,
+                                        addr.ipaddr(), 0, 0,
+                                        username_, password_);
+    // TODO: Add an external address for ext_proto, so that the
+    // other side can connect to this port using a non-UDP protocol.
+    port->SetIceProtocolType(ice_protocol_);
+    return port;
+  }
+  rtc::NATServer* CreateNatServer(const SocketAddress& addr,
+                                        rtc::NATType type) {
+    return new rtc::NATServer(type, ss_.get(), addr, ss_.get(), addr);
+  }
+  static const char* StunName(NATType type) {
+    switch (type) {
+      case NAT_OPEN_CONE:       return "stun(open cone)";
+      case NAT_ADDR_RESTRICTED: return "stun(addr restricted)";
+      case NAT_PORT_RESTRICTED: return "stun(port restricted)";
+      case NAT_SYMMETRIC:       return "stun(symmetric)";
+      default:                  return "stun(?)";
+    }
+  }
+  static const char* RelayName(RelayType type, ProtocolType proto) {
+    if (type == RELAY_TURN) {
+      switch (proto) {
+        case PROTO_UDP:           return "turn(udp)";
+        case PROTO_TCP:           return "turn(tcp)";
+        case PROTO_SSLTCP:        return "turn(ssltcp)";
+        default:                  return "turn(?)";
+      }
+    } else {
+      switch (proto) {
+        case PROTO_UDP:           return "gturn(udp)";
+        case PROTO_TCP:           return "gturn(tcp)";
+        case PROTO_SSLTCP:        return "gturn(ssltcp)";
+        default:                  return "gturn(?)";
+      }
+    }
+  }
+
+  void TestCrossFamilyPorts(int type);
+
+  // This does all the work and then deletes |port1| and |port2|.
+  void TestConnectivity(const char* name1, Port* port1,
+                        const char* name2, Port* port2,
+                        bool accept, bool same_addr1,
+                        bool same_addr2, bool possible);
+
+  // This connects and disconnects the provided channels in the same sequence as
+  // TestConnectivity with all options set to |true|.  It does not delete either
+  // channel.
+  void ConnectAndDisconnectChannels(TestChannel* ch1, TestChannel* ch2);
+
+  void SetIceProtocolType(cricket::IceProtocolType protocol) {
+    ice_protocol_ = protocol;
+  }
+
+  IceMessage* CreateStunMessage(int type) {
+    IceMessage* msg = new IceMessage();
+    msg->SetType(type);
+    msg->SetTransactionID("TESTTESTTEST");
+    return msg;
+  }
+  IceMessage* CreateStunMessageWithUsername(int type,
+                                            const std::string& username) {
+    IceMessage* msg = CreateStunMessage(type);
+    msg->AddAttribute(
+        new StunByteStringAttribute(STUN_ATTR_USERNAME, username));
+    return msg;
+  }
+  TestPort* CreateTestPort(const rtc::SocketAddress& addr,
+                           const std::string& username,
+                           const std::string& password) {
+    TestPort* port =  new TestPort(main_, "test", &socket_factory_, &network_,
+                                   addr.ipaddr(), 0, 0, username, password);
+    port->SignalRoleConflict.connect(this, &PortTest::OnRoleConflict);
+    return port;
+  }
+  TestPort* CreateTestPort(const rtc::SocketAddress& addr,
+                           const std::string& username,
+                           const std::string& password,
+                           cricket::IceProtocolType type,
+                           cricket::IceRole role,
+                           int tiebreaker) {
+    TestPort* port = CreateTestPort(addr, username, password);
+    port->SetIceProtocolType(type);
+    port->SetIceRole(role);
+    port->SetIceTiebreaker(tiebreaker);
+    return port;
+  }
+
+  void OnRoleConflict(PortInterface* port) {
+    role_conflict_ = true;
+  }
+  bool role_conflict() const { return role_conflict_; }
+
+  void ConnectToSignalDestroyed(PortInterface* port) {
+    port->SignalDestroyed.connect(this, &PortTest::OnDestroyed);
+  }
+
+  void OnDestroyed(PortInterface* port) {
+    destroyed_ = true;
+  }
+  bool destroyed() const { return destroyed_; }
+
+  rtc::BasicPacketSocketFactory* nat_socket_factory1() {
+    return &nat_socket_factory1_;
+  }
+
+ private:
+  rtc::Thread* main_;
+  rtc::scoped_ptr<rtc::PhysicalSocketServer> pss_;
+  rtc::scoped_ptr<rtc::VirtualSocketServer> ss_;
+  rtc::SocketServerScope ss_scope_;
+  rtc::Network network_;
+  rtc::BasicPacketSocketFactory socket_factory_;
+  rtc::scoped_ptr<rtc::NATServer> nat_server1_;
+  rtc::scoped_ptr<rtc::NATServer> nat_server2_;
+  rtc::NATSocketFactory nat_factory1_;
+  rtc::NATSocketFactory nat_factory2_;
+  rtc::BasicPacketSocketFactory nat_socket_factory1_;
+  rtc::BasicPacketSocketFactory nat_socket_factory2_;
+  scoped_ptr<TestStunServer> stun_server_;
+  TestTurnServer turn_server_;
+  TestRelayServer relay_server_;
+  std::string username_;
+  std::string password_;
+  cricket::IceProtocolType ice_protocol_;
+  bool role_conflict_;
+  bool destroyed_;
+};
+
+void PortTest::TestConnectivity(const char* name1, Port* port1,
+                                const char* name2, Port* port2,
+                                bool accept, bool same_addr1,
+                                bool same_addr2, bool possible) {
+  LOG(LS_INFO) << "Test: " << name1 << " to " << name2 << ": ";
+  port1->set_component(cricket::ICE_CANDIDATE_COMPONENT_DEFAULT);
+  port2->set_component(cricket::ICE_CANDIDATE_COMPONENT_DEFAULT);
+
+  // Set up channels and ensure both ports will be deleted.
+  TestChannel ch1(port1, port2);
+  TestChannel ch2(port2, port1);
+  EXPECT_EQ(0, ch1.complete_count());
+  EXPECT_EQ(0, ch2.complete_count());
+
+  // Acquire addresses.
+  ch1.Start();
+  ch2.Start();
+  ASSERT_EQ_WAIT(1, ch1.complete_count(), kTimeout);
+  ASSERT_EQ_WAIT(1, ch2.complete_count(), kTimeout);
+
+  // Send a ping from src to dst. This may or may not make it.
+  ch1.CreateConnection();
+  ASSERT_TRUE(ch1.conn() != NULL);
+  EXPECT_TRUE_WAIT(ch1.conn()->connected(), kTimeout);  // for TCP connect
+  ch1.Ping();
+  WAIT(!ch2.remote_address().IsNil(), kTimeout);
+
+  if (accept) {
+    // We are able to send a ping from src to dst. This is the case when
+    // sending to UDP ports and cone NATs.
+    EXPECT_TRUE(ch1.remote_address().IsNil());
+    EXPECT_EQ(ch2.remote_fragment(), port1->username_fragment());
+
+    // Ensure the ping came from the same address used for src.
+    // This is the case unless the source NAT was symmetric.
+    if (same_addr1) EXPECT_EQ(ch2.remote_address(), GetAddress(port1));
+    EXPECT_TRUE(same_addr2);
+
+    // Send a ping from dst to src.
+    ch2.AcceptConnection();
+    ASSERT_TRUE(ch2.conn() != NULL);
+    ch2.Ping();
+    EXPECT_EQ_WAIT(Connection::STATE_WRITABLE, ch2.conn()->write_state(),
+                   kTimeout);
+  } else {
+    // We can't send a ping from src to dst, so flip it around. This will happen
+    // when the destination NAT is addr/port restricted or symmetric.
+    EXPECT_TRUE(ch1.remote_address().IsNil());
+    EXPECT_TRUE(ch2.remote_address().IsNil());
+
+    // Send a ping from dst to src. Again, this may or may not make it.
+    ch2.CreateConnection();
+    ASSERT_TRUE(ch2.conn() != NULL);
+    ch2.Ping();
+    WAIT(ch2.conn()->write_state() == Connection::STATE_WRITABLE, kTimeout);
+
+    if (same_addr1 && same_addr2) {
+      // The new ping got back to the source.
+      EXPECT_EQ(Connection::STATE_READABLE, ch1.conn()->read_state());
+      EXPECT_EQ(Connection::STATE_WRITABLE, ch2.conn()->write_state());
+
+      // First connection may not be writable if the first ping did not get
+      // through.  So we will have to do another.
+      if (ch1.conn()->write_state() == Connection::STATE_WRITE_INIT) {
+        ch1.Ping();
+        EXPECT_EQ_WAIT(Connection::STATE_WRITABLE, ch1.conn()->write_state(),
+                       kTimeout);
+      }
+    } else if (!same_addr1 && possible) {
+      // The new ping went to the candidate address, but that address was bad.
+      // This will happen when the source NAT is symmetric.
+      EXPECT_TRUE(ch1.remote_address().IsNil());
+      EXPECT_TRUE(ch2.remote_address().IsNil());
+
+      // However, since we have now sent a ping to the source IP, we should be
+      // able to get a ping from it. This gives us the real source address.
+      ch1.Ping();
+      EXPECT_TRUE_WAIT(!ch2.remote_address().IsNil(), kTimeout);
+      EXPECT_EQ(Connection::STATE_READ_INIT, ch2.conn()->read_state());
+      EXPECT_TRUE(ch1.remote_address().IsNil());
+
+      // Pick up the actual address and establish the connection.
+      ch2.AcceptConnection();
+      ASSERT_TRUE(ch2.conn() != NULL);
+      ch2.Ping();
+      EXPECT_EQ_WAIT(Connection::STATE_WRITABLE, ch2.conn()->write_state(),
+                     kTimeout);
+    } else if (!same_addr2 && possible) {
+      // The new ping came in, but from an unexpected address. This will happen
+      // when the destination NAT is symmetric.
+      EXPECT_FALSE(ch1.remote_address().IsNil());
+      EXPECT_EQ(Connection::STATE_READ_INIT, ch1.conn()->read_state());
+
+      // Update our address and complete the connection.
+      ch1.AcceptConnection();
+      ch1.Ping();
+      EXPECT_EQ_WAIT(Connection::STATE_WRITABLE, ch1.conn()->write_state(),
+                     kTimeout);
+    } else {  // (!possible)
+      // There should be s no way for the pings to reach each other. Check it.
+      EXPECT_TRUE(ch1.remote_address().IsNil());
+      EXPECT_TRUE(ch2.remote_address().IsNil());
+      ch1.Ping();
+      WAIT(!ch2.remote_address().IsNil(), kTimeout);
+      EXPECT_TRUE(ch1.remote_address().IsNil());
+      EXPECT_TRUE(ch2.remote_address().IsNil());
+    }
+  }
+
+  // Everything should be good, unless we know the situation is impossible.
+  ASSERT_TRUE(ch1.conn() != NULL);
+  ASSERT_TRUE(ch2.conn() != NULL);
+  if (possible) {
+    EXPECT_EQ(Connection::STATE_READABLE, ch1.conn()->read_state());
+    EXPECT_EQ(Connection::STATE_WRITABLE, ch1.conn()->write_state());
+    EXPECT_EQ(Connection::STATE_READABLE, ch2.conn()->read_state());
+    EXPECT_EQ(Connection::STATE_WRITABLE, ch2.conn()->write_state());
+  } else {
+    EXPECT_NE(Connection::STATE_READABLE, ch1.conn()->read_state());
+    EXPECT_NE(Connection::STATE_WRITABLE, ch1.conn()->write_state());
+    EXPECT_NE(Connection::STATE_READABLE, ch2.conn()->read_state());
+    EXPECT_NE(Connection::STATE_WRITABLE, ch2.conn()->write_state());
+  }
+
+  // Tear down and ensure that goes smoothly.
+  ch1.Stop();
+  ch2.Stop();
+  EXPECT_TRUE_WAIT(ch1.conn() == NULL, kTimeout);
+  EXPECT_TRUE_WAIT(ch2.conn() == NULL, kTimeout);
+}
+
+void PortTest::ConnectAndDisconnectChannels(TestChannel* ch1,
+                                            TestChannel* ch2) {
+  // Acquire addresses.
+  ch1->Start();
+  ch2->Start();
+
+  // Send a ping from src to dst.
+  ch1->CreateConnection();
+  EXPECT_TRUE_WAIT(ch1->conn()->connected(), kTimeout);  // for TCP connect
+  ch1->Ping();
+  WAIT(!ch2->remote_address().IsNil(), kTimeout);
+
+  // Send a ping from dst to src.
+  ch2->AcceptConnection();
+  ch2->Ping();
+  EXPECT_EQ_WAIT(Connection::STATE_WRITABLE, ch2->conn()->write_state(),
+                 kTimeout);
+
+  // Destroy the connections.
+  ch1->Stop();
+  ch2->Stop();
+}
+
+class FakePacketSocketFactory : public rtc::PacketSocketFactory {
+ public:
+  FakePacketSocketFactory()
+      : next_udp_socket_(NULL),
+        next_server_tcp_socket_(NULL),
+        next_client_tcp_socket_(NULL) {
+  }
+  virtual ~FakePacketSocketFactory() { }
+
+  virtual AsyncPacketSocket* CreateUdpSocket(
+      const SocketAddress& address, int min_port, int max_port) {
+    EXPECT_TRUE(next_udp_socket_ != NULL);
+    AsyncPacketSocket* result = next_udp_socket_;
+    next_udp_socket_ = NULL;
+    return result;
+  }
+
+  virtual AsyncPacketSocket* CreateServerTcpSocket(
+      const SocketAddress& local_address, int min_port, int max_port,
+      int opts) {
+    EXPECT_TRUE(next_server_tcp_socket_ != NULL);
+    AsyncPacketSocket* result = next_server_tcp_socket_;
+    next_server_tcp_socket_ = NULL;
+    return result;
+  }
+
+  // TODO: |proxy_info| and |user_agent| should be set
+  // per-factory and not when socket is created.
+  virtual AsyncPacketSocket* CreateClientTcpSocket(
+      const SocketAddress& local_address, const SocketAddress& remote_address,
+      const rtc::ProxyInfo& proxy_info,
+      const std::string& user_agent, int opts) {
+    EXPECT_TRUE(next_client_tcp_socket_ != NULL);
+    AsyncPacketSocket* result = next_client_tcp_socket_;
+    next_client_tcp_socket_ = NULL;
+    return result;
+  }
+
+  void set_next_udp_socket(AsyncPacketSocket* next_udp_socket) {
+    next_udp_socket_ = next_udp_socket;
+  }
+  void set_next_server_tcp_socket(AsyncPacketSocket* next_server_tcp_socket) {
+    next_server_tcp_socket_ = next_server_tcp_socket;
+  }
+  void set_next_client_tcp_socket(AsyncPacketSocket* next_client_tcp_socket) {
+    next_client_tcp_socket_ = next_client_tcp_socket;
+  }
+  rtc::AsyncResolverInterface* CreateAsyncResolver() {
+    return NULL;
+  }
+
+ private:
+  AsyncPacketSocket* next_udp_socket_;
+  AsyncPacketSocket* next_server_tcp_socket_;
+  AsyncPacketSocket* next_client_tcp_socket_;
+};
+
+class FakeAsyncPacketSocket : public AsyncPacketSocket {
+ public:
+  // Returns current local address. Address may be set to NULL if the
+  // socket is not bound yet (GetState() returns STATE_BINDING).
+  virtual SocketAddress GetLocalAddress() const {
+    return SocketAddress();
+  }
+
+  // Returns remote address. Returns zeroes if this is not a client TCP socket.
+  virtual SocketAddress GetRemoteAddress() const {
+    return SocketAddress();
+  }
+
+  // Send a packet.
+  virtual int Send(const void *pv, size_t cb,
+                   const rtc::PacketOptions& options) {
+    return static_cast<int>(cb);
+  }
+  virtual int SendTo(const void *pv, size_t cb, const SocketAddress& addr,
+                     const rtc::PacketOptions& options) {
+    return static_cast<int>(cb);
+  }
+  virtual int Close() {
+    return 0;
+  }
+
+  virtual State GetState() const { return state_; }
+  virtual int GetOption(Socket::Option opt, int* value) { return 0; }
+  virtual int SetOption(Socket::Option opt, int value) { return 0; }
+  virtual int GetError() const { return 0; }
+  virtual void SetError(int error) { }
+
+  void set_state(State state) { state_ = state; }
+
+ private:
+  State state_;
+};
+
+// Local -> XXXX
+TEST_F(PortTest, TestLocalToLocal) {
+  TestLocalToLocal();
+}
+
+TEST_F(PortTest, TestLocalToConeNat) {
+  TestLocalToStun(NAT_OPEN_CONE);
+}
+
+TEST_F(PortTest, TestLocalToARNat) {
+  TestLocalToStun(NAT_ADDR_RESTRICTED);
+}
+
+TEST_F(PortTest, TestLocalToPRNat) {
+  TestLocalToStun(NAT_PORT_RESTRICTED);
+}
+
+TEST_F(PortTest, TestLocalToSymNat) {
+  TestLocalToStun(NAT_SYMMETRIC);
+}
+
+// Flaky: https://code.google.com/p/webrtc/issues/detail?id=3316.
+TEST_F(PortTest, DISABLED_TestLocalToTurn) {
+  TestLocalToRelay(RELAY_TURN, PROTO_UDP);
+}
+
+TEST_F(PortTest, TestLocalToGturn) {
+  TestLocalToRelay(RELAY_GTURN, PROTO_UDP);
+}
+
+TEST_F(PortTest, TestLocalToTcpGturn) {
+  TestLocalToRelay(RELAY_GTURN, PROTO_TCP);
+}
+
+TEST_F(PortTest, TestLocalToSslTcpGturn) {
+  TestLocalToRelay(RELAY_GTURN, PROTO_SSLTCP);
+}
+
+// Cone NAT -> XXXX
+TEST_F(PortTest, TestConeNatToLocal) {
+  TestStunToLocal(NAT_OPEN_CONE);
+}
+
+TEST_F(PortTest, TestConeNatToConeNat) {
+  TestStunToStun(NAT_OPEN_CONE, NAT_OPEN_CONE);
+}
+
+TEST_F(PortTest, TestConeNatToARNat) {
+  TestStunToStun(NAT_OPEN_CONE, NAT_ADDR_RESTRICTED);
+}
+
+TEST_F(PortTest, TestConeNatToPRNat) {
+  TestStunToStun(NAT_OPEN_CONE, NAT_PORT_RESTRICTED);
+}
+
+TEST_F(PortTest, TestConeNatToSymNat) {
+  TestStunToStun(NAT_OPEN_CONE, NAT_SYMMETRIC);
+}
+
+TEST_F(PortTest, TestConeNatToTurn) {
+  TestStunToRelay(NAT_OPEN_CONE, RELAY_TURN, PROTO_UDP);
+}
+
+TEST_F(PortTest, TestConeNatToGturn) {
+  TestStunToRelay(NAT_OPEN_CONE, RELAY_GTURN, PROTO_UDP);
+}
+
+TEST_F(PortTest, TestConeNatToTcpGturn) {
+  TestStunToRelay(NAT_OPEN_CONE, RELAY_GTURN, PROTO_TCP);
+}
+
+// Address-restricted NAT -> XXXX
+TEST_F(PortTest, TestARNatToLocal) {
+  TestStunToLocal(NAT_ADDR_RESTRICTED);
+}
+
+TEST_F(PortTest, TestARNatToConeNat) {
+  TestStunToStun(NAT_ADDR_RESTRICTED, NAT_OPEN_CONE);
+}
+
+TEST_F(PortTest, TestARNatToARNat) {
+  TestStunToStun(NAT_ADDR_RESTRICTED, NAT_ADDR_RESTRICTED);
+}
+
+TEST_F(PortTest, TestARNatToPRNat) {
+  TestStunToStun(NAT_ADDR_RESTRICTED, NAT_PORT_RESTRICTED);
+}
+
+TEST_F(PortTest, TestARNatToSymNat) {
+  TestStunToStun(NAT_ADDR_RESTRICTED, NAT_SYMMETRIC);
+}
+
+TEST_F(PortTest, TestARNatToTurn) {
+  TestStunToRelay(NAT_ADDR_RESTRICTED, RELAY_TURN, PROTO_UDP);
+}
+
+TEST_F(PortTest, TestARNatToGturn) {
+  TestStunToRelay(NAT_ADDR_RESTRICTED, RELAY_GTURN, PROTO_UDP);
+}
+
+TEST_F(PortTest, TestARNATNatToTcpGturn) {
+  TestStunToRelay(NAT_ADDR_RESTRICTED, RELAY_GTURN, PROTO_TCP);
+}
+
+// Port-restricted NAT -> XXXX
+TEST_F(PortTest, TestPRNatToLocal) {
+  TestStunToLocal(NAT_PORT_RESTRICTED);
+}
+
+TEST_F(PortTest, TestPRNatToConeNat) {
+  TestStunToStun(NAT_PORT_RESTRICTED, NAT_OPEN_CONE);
+}
+
+TEST_F(PortTest, TestPRNatToARNat) {
+  TestStunToStun(NAT_PORT_RESTRICTED, NAT_ADDR_RESTRICTED);
+}
+
+TEST_F(PortTest, TestPRNatToPRNat) {
+  TestStunToStun(NAT_PORT_RESTRICTED, NAT_PORT_RESTRICTED);
+}
+
+TEST_F(PortTest, TestPRNatToSymNat) {
+  // Will "fail"
+  TestStunToStun(NAT_PORT_RESTRICTED, NAT_SYMMETRIC);
+}
+
+TEST_F(PortTest, TestPRNatToTurn) {
+  TestStunToRelay(NAT_PORT_RESTRICTED, RELAY_TURN, PROTO_UDP);
+}
+
+TEST_F(PortTest, TestPRNatToGturn) {
+  TestStunToRelay(NAT_PORT_RESTRICTED, RELAY_GTURN, PROTO_UDP);
+}
+
+TEST_F(PortTest, TestPRNatToTcpGturn) {
+  TestStunToRelay(NAT_PORT_RESTRICTED, RELAY_GTURN, PROTO_TCP);
+}
+
+// Symmetric NAT -> XXXX
+TEST_F(PortTest, TestSymNatToLocal) {
+  TestStunToLocal(NAT_SYMMETRIC);
+}
+
+TEST_F(PortTest, TestSymNatToConeNat) {
+  TestStunToStun(NAT_SYMMETRIC, NAT_OPEN_CONE);
+}
+
+TEST_F(PortTest, TestSymNatToARNat) {
+  TestStunToStun(NAT_SYMMETRIC, NAT_ADDR_RESTRICTED);
+}
+
+TEST_F(PortTest, TestSymNatToPRNat) {
+  // Will "fail"
+  TestStunToStun(NAT_SYMMETRIC, NAT_PORT_RESTRICTED);
+}
+
+TEST_F(PortTest, TestSymNatToSymNat) {
+  // Will "fail"
+  TestStunToStun(NAT_SYMMETRIC, NAT_SYMMETRIC);
+}
+
+TEST_F(PortTest, TestSymNatToTurn) {
+  TestStunToRelay(NAT_SYMMETRIC, RELAY_TURN, PROTO_UDP);
+}
+
+TEST_F(PortTest, TestSymNatToGturn) {
+  TestStunToRelay(NAT_SYMMETRIC, RELAY_GTURN, PROTO_UDP);
+}
+
+TEST_F(PortTest, TestSymNatToTcpGturn) {
+  TestStunToRelay(NAT_SYMMETRIC, RELAY_GTURN, PROTO_TCP);
+}
+
+// Outbound TCP -> XXXX
+TEST_F(PortTest, TestTcpToTcp) {
+  TestTcpToTcp();
+}
+
+/* TODO: Enable these once testrelayserver can accept external TCP.
+TEST_F(PortTest, TestTcpToTcpRelay) {
+  TestTcpToRelay(PROTO_TCP);
+}
+
+TEST_F(PortTest, TestTcpToSslTcpRelay) {
+  TestTcpToRelay(PROTO_SSLTCP);
+}
+*/
+
+// Outbound SSLTCP -> XXXX
+/* TODO: Enable these once testrelayserver can accept external SSL.
+TEST_F(PortTest, TestSslTcpToTcpRelay) {
+  TestSslTcpToRelay(PROTO_TCP);
+}
+
+TEST_F(PortTest, TestSslTcpToSslTcpRelay) {
+  TestSslTcpToRelay(PROTO_SSLTCP);
+}
+*/
+
+// This test case verifies standard ICE features in STUN messages. Currently it
+// verifies Message Integrity attribute in STUN messages and username in STUN
+// binding request will have colon (":") between remote and local username.
+TEST_F(PortTest, TestLocalToLocalAsIce) {
+  SetIceProtocolType(cricket::ICEPROTO_RFC5245);
+  UDPPort* port1 = CreateUdpPort(kLocalAddr1);
+  port1->SetIceRole(cricket::ICEROLE_CONTROLLING);
+  port1->SetIceTiebreaker(kTiebreaker1);
+  ASSERT_EQ(cricket::ICEPROTO_RFC5245, port1->IceProtocol());
+  UDPPort* port2 = CreateUdpPort(kLocalAddr2);
+  port2->SetIceRole(cricket::ICEROLE_CONTROLLED);
+  port2->SetIceTiebreaker(kTiebreaker2);
+  ASSERT_EQ(cricket::ICEPROTO_RFC5245, port2->IceProtocol());
+  // Same parameters as TestLocalToLocal above.
+  TestConnectivity("udp", port1, "udp", port2, true, true, true, true);
+}
+
+// This test is trying to validate a successful and failure scenario in a
+// loopback test when protocol is RFC5245. For success IceTiebreaker, username
+// should remain equal to the request generated by the port and role of port
+// must be in controlling.
+TEST_F(PortTest, TestLoopbackCallAsIce) {
+  rtc::scoped_ptr<TestPort> lport(
+      CreateTestPort(kLocalAddr1, "lfrag", "lpass"));
+  lport->SetIceProtocolType(ICEPROTO_RFC5245);
+  lport->SetIceRole(cricket::ICEROLE_CONTROLLING);
+  lport->SetIceTiebreaker(kTiebreaker1);
+  lport->PrepareAddress();
+  ASSERT_FALSE(lport->Candidates().empty());
+  Connection* conn = lport->CreateConnection(lport->Candidates()[0],
+                                             Port::ORIGIN_MESSAGE);
+  conn->Ping(0);
+
+  ASSERT_TRUE_WAIT(lport->last_stun_msg() != NULL, 1000);
+  IceMessage* msg = lport->last_stun_msg();
+  EXPECT_EQ(STUN_BINDING_REQUEST, msg->type());
+  conn->OnReadPacket(lport->last_stun_buf()->Data(),
+                     lport->last_stun_buf()->Length(),
+                     rtc::PacketTime());
+  ASSERT_TRUE_WAIT(lport->last_stun_msg() != NULL, 1000);
+  msg = lport->last_stun_msg();
+  EXPECT_EQ(STUN_BINDING_RESPONSE, msg->type());
+
+  // If the tiebreaker value is different from port, we expect a error
+  // response.
+  lport->Reset();
+  lport->AddCandidateAddress(kLocalAddr2);
+  // Creating a different connection as |conn| is in STATE_READABLE.
+  Connection* conn1 = lport->CreateConnection(lport->Candidates()[1],
+                                              Port::ORIGIN_MESSAGE);
+  conn1->Ping(0);
+
+  ASSERT_TRUE_WAIT(lport->last_stun_msg() != NULL, 1000);
+  msg = lport->last_stun_msg();
+  EXPECT_EQ(STUN_BINDING_REQUEST, msg->type());
+  rtc::scoped_ptr<IceMessage> modified_req(
+      CreateStunMessage(STUN_BINDING_REQUEST));
+  const StunByteStringAttribute* username_attr = msg->GetByteString(
+      STUN_ATTR_USERNAME);
+  modified_req->AddAttribute(new StunByteStringAttribute(
+      STUN_ATTR_USERNAME, username_attr->GetString()));
+  // To make sure we receive error response, adding tiebreaker less than
+  // what's present in request.
+  modified_req->AddAttribute(new StunUInt64Attribute(
+      STUN_ATTR_ICE_CONTROLLING, kTiebreaker1 - 1));
+  modified_req->AddMessageIntegrity("lpass");
+  modified_req->AddFingerprint();
+
+  lport->Reset();
+  rtc::scoped_ptr<ByteBuffer> buf(new ByteBuffer());
+  WriteStunMessage(modified_req.get(), buf.get());
+  conn1->OnReadPacket(buf->Data(), buf->Length(), rtc::PacketTime());
+  ASSERT_TRUE_WAIT(lport->last_stun_msg() != NULL, 1000);
+  msg = lport->last_stun_msg();
+  EXPECT_EQ(STUN_BINDING_ERROR_RESPONSE, msg->type());
+}
+
+// This test verifies role conflict signal is received when there is
+// conflict in the role. In this case both ports are in controlling and
+// |rport| has higher tiebreaker value than |lport|. Since |lport| has lower
+// value of tiebreaker, when it receives ping request from |rport| it will
+// send role conflict signal.
+TEST_F(PortTest, TestIceRoleConflict) {
+  rtc::scoped_ptr<TestPort> lport(
+      CreateTestPort(kLocalAddr1, "lfrag", "lpass"));
+  lport->SetIceProtocolType(ICEPROTO_RFC5245);
+  lport->SetIceRole(cricket::ICEROLE_CONTROLLING);
+  lport->SetIceTiebreaker(kTiebreaker1);
+  rtc::scoped_ptr<TestPort> rport(
+      CreateTestPort(kLocalAddr2, "rfrag", "rpass"));
+  rport->SetIceProtocolType(ICEPROTO_RFC5245);
+  rport->SetIceRole(cricket::ICEROLE_CONTROLLING);
+  rport->SetIceTiebreaker(kTiebreaker2);
+
+  lport->PrepareAddress();
+  rport->PrepareAddress();
+  ASSERT_FALSE(lport->Candidates().empty());
+  ASSERT_FALSE(rport->Candidates().empty());
+  Connection* lconn = lport->CreateConnection(rport->Candidates()[0],
+                                              Port::ORIGIN_MESSAGE);
+  Connection* rconn = rport->CreateConnection(lport->Candidates()[0],
+                                              Port::ORIGIN_MESSAGE);
+  rconn->Ping(0);
+
+  ASSERT_TRUE_WAIT(rport->last_stun_msg() != NULL, 1000);
+  IceMessage* msg = rport->last_stun_msg();
+  EXPECT_EQ(STUN_BINDING_REQUEST, msg->type());
+  // Send rport binding request to lport.
+  lconn->OnReadPacket(rport->last_stun_buf()->Data(),
+                      rport->last_stun_buf()->Length(),
+                      rtc::PacketTime());
+
+  ASSERT_TRUE_WAIT(lport->last_stun_msg() != NULL, 1000);
+  EXPECT_EQ(STUN_BINDING_RESPONSE, lport->last_stun_msg()->type());
+  EXPECT_TRUE(role_conflict());
+}
+
+TEST_F(PortTest, TestTcpNoDelay) {
+  TCPPort* port1 = CreateTcpPort(kLocalAddr1);
+  int option_value = -1;
+  int success = port1->GetOption(rtc::Socket::OPT_NODELAY,
+                                 &option_value);
+  ASSERT_EQ(0, success);  // GetOption() should complete successfully w/ 0
+  ASSERT_EQ(1, option_value);
+  delete port1;
+}
+
+TEST_F(PortTest, TestDelayedBindingUdp) {
+  FakeAsyncPacketSocket *socket = new FakeAsyncPacketSocket();
+  FakePacketSocketFactory socket_factory;
+
+  socket_factory.set_next_udp_socket(socket);
+  scoped_ptr<UDPPort> port(
+      CreateUdpPort(kLocalAddr1, &socket_factory));
+
+  socket->set_state(AsyncPacketSocket::STATE_BINDING);
+  port->PrepareAddress();
+
+  EXPECT_EQ(0U, port->Candidates().size());
+  socket->SignalAddressReady(socket, kLocalAddr2);
+
+  EXPECT_EQ(1U, port->Candidates().size());
+}
+
+TEST_F(PortTest, TestDelayedBindingTcp) {
+  FakeAsyncPacketSocket *socket = new FakeAsyncPacketSocket();
+  FakePacketSocketFactory socket_factory;
+
+  socket_factory.set_next_server_tcp_socket(socket);
+  scoped_ptr<TCPPort> port(
+      CreateTcpPort(kLocalAddr1, &socket_factory));
+
+  socket->set_state(AsyncPacketSocket::STATE_BINDING);
+  port->PrepareAddress();
+
+  EXPECT_EQ(0U, port->Candidates().size());
+  socket->SignalAddressReady(socket, kLocalAddr2);
+
+  EXPECT_EQ(1U, port->Candidates().size());
+}
+
+void PortTest::TestCrossFamilyPorts(int type) {
+  FakePacketSocketFactory factory;
+  scoped_ptr<Port> ports[4];
+  SocketAddress addresses[4] = {SocketAddress("192.168.1.3", 0),
+                                SocketAddress("192.168.1.4", 0),
+                                SocketAddress("2001:db8::1", 0),
+                                SocketAddress("2001:db8::2", 0)};
+  for (int i = 0; i < 4; i++) {
+    FakeAsyncPacketSocket *socket = new FakeAsyncPacketSocket();
+    if (type == SOCK_DGRAM) {
+      factory.set_next_udp_socket(socket);
+      ports[i].reset(CreateUdpPort(addresses[i], &factory));
+    } else if (type == SOCK_STREAM) {
+      factory.set_next_server_tcp_socket(socket);
+      ports[i].reset(CreateTcpPort(addresses[i], &factory));
+    }
+    socket->set_state(AsyncPacketSocket::STATE_BINDING);
+    socket->SignalAddressReady(socket, addresses[i]);
+    ports[i]->PrepareAddress();
+  }
+
+  // IPv4 Port, connects to IPv6 candidate and then to IPv4 candidate.
+  if (type == SOCK_STREAM) {
+    FakeAsyncPacketSocket* clientsocket = new FakeAsyncPacketSocket();
+    factory.set_next_client_tcp_socket(clientsocket);
+  }
+  Connection* c = ports[0]->CreateConnection(GetCandidate(ports[2].get()),
+                                             Port::ORIGIN_MESSAGE);
+  EXPECT_TRUE(NULL == c);
+  EXPECT_EQ(0U, ports[0]->connections().size());
+  c = ports[0]->CreateConnection(GetCandidate(ports[1].get()),
+                                 Port::ORIGIN_MESSAGE);
+  EXPECT_FALSE(NULL == c);
+  EXPECT_EQ(1U, ports[0]->connections().size());
+
+  // IPv6 Port, connects to IPv4 candidate and to IPv6 candidate.
+  if (type == SOCK_STREAM) {
+    FakeAsyncPacketSocket* clientsocket = new FakeAsyncPacketSocket();
+    factory.set_next_client_tcp_socket(clientsocket);
+  }
+  c = ports[2]->CreateConnection(GetCandidate(ports[0].get()),
+                                 Port::ORIGIN_MESSAGE);
+  EXPECT_TRUE(NULL == c);
+  EXPECT_EQ(0U, ports[2]->connections().size());
+  c = ports[2]->CreateConnection(GetCandidate(ports[3].get()),
+                                 Port::ORIGIN_MESSAGE);
+  EXPECT_FALSE(NULL == c);
+  EXPECT_EQ(1U, ports[2]->connections().size());
+}
+
+TEST_F(PortTest, TestSkipCrossFamilyTcp) {
+  TestCrossFamilyPorts(SOCK_STREAM);
+}
+
+TEST_F(PortTest, TestSkipCrossFamilyUdp) {
+  TestCrossFamilyPorts(SOCK_DGRAM);
+}
+
+// This test verifies DSCP value set through SetOption interface can be
+// get through DefaultDscpValue.
+TEST_F(PortTest, TestDefaultDscpValue) {
+  int dscp;
+  rtc::scoped_ptr<UDPPort> udpport(CreateUdpPort(kLocalAddr1));
+  EXPECT_EQ(0, udpport->SetOption(rtc::Socket::OPT_DSCP,
+                                  rtc::DSCP_CS6));
+  EXPECT_EQ(0, udpport->GetOption(rtc::Socket::OPT_DSCP, &dscp));
+  rtc::scoped_ptr<TCPPort> tcpport(CreateTcpPort(kLocalAddr1));
+  EXPECT_EQ(0, tcpport->SetOption(rtc::Socket::OPT_DSCP,
+                                 rtc::DSCP_AF31));
+  EXPECT_EQ(0, tcpport->GetOption(rtc::Socket::OPT_DSCP, &dscp));
+  EXPECT_EQ(rtc::DSCP_AF31, dscp);
+  rtc::scoped_ptr<StunPort> stunport(
+      CreateStunPort(kLocalAddr1, nat_socket_factory1()));
+  EXPECT_EQ(0, stunport->SetOption(rtc::Socket::OPT_DSCP,
+                                  rtc::DSCP_AF41));
+  EXPECT_EQ(0, stunport->GetOption(rtc::Socket::OPT_DSCP, &dscp));
+  EXPECT_EQ(rtc::DSCP_AF41, dscp);
+  rtc::scoped_ptr<TurnPort> turnport1(CreateTurnPort(
+      kLocalAddr1, nat_socket_factory1(), PROTO_UDP, PROTO_UDP));
+  // Socket is created in PrepareAddress.
+  turnport1->PrepareAddress();
+  EXPECT_EQ(0, turnport1->SetOption(rtc::Socket::OPT_DSCP,
+                                  rtc::DSCP_CS7));
+  EXPECT_EQ(0, turnport1->GetOption(rtc::Socket::OPT_DSCP, &dscp));
+  EXPECT_EQ(rtc::DSCP_CS7, dscp);
+  // This will verify correct value returned without the socket.
+  rtc::scoped_ptr<TurnPort> turnport2(CreateTurnPort(
+      kLocalAddr1, nat_socket_factory1(), PROTO_UDP, PROTO_UDP));
+  EXPECT_EQ(0, turnport2->SetOption(rtc::Socket::OPT_DSCP,
+                                  rtc::DSCP_CS6));
+  EXPECT_EQ(0, turnport2->GetOption(rtc::Socket::OPT_DSCP, &dscp));
+  EXPECT_EQ(rtc::DSCP_CS6, dscp);
+}
+
+// Test sending STUN messages in GICE format.
+TEST_F(PortTest, TestSendStunMessageAsGice) {
+  rtc::scoped_ptr<TestPort> lport(
+      CreateTestPort(kLocalAddr1, "lfrag", "lpass"));
+  rtc::scoped_ptr<TestPort> rport(
+      CreateTestPort(kLocalAddr2, "rfrag", "rpass"));
+  lport->SetIceProtocolType(ICEPROTO_GOOGLE);
+  rport->SetIceProtocolType(ICEPROTO_GOOGLE);
+
+  // Send a fake ping from lport to rport.
+  lport->PrepareAddress();
+  rport->PrepareAddress();
+  ASSERT_FALSE(rport->Candidates().empty());
+  Connection* conn = lport->CreateConnection(rport->Candidates()[0],
+      Port::ORIGIN_MESSAGE);
+  rport->CreateConnection(lport->Candidates()[0], Port::ORIGIN_MESSAGE);
+  conn->Ping(0);
+
+  // Check that it's a proper BINDING-REQUEST.
+  ASSERT_TRUE_WAIT(lport->last_stun_msg() != NULL, 1000);
+  IceMessage* msg = lport->last_stun_msg();
+  EXPECT_EQ(STUN_BINDING_REQUEST, msg->type());
+  EXPECT_FALSE(msg->IsLegacy());
+  const StunByteStringAttribute* username_attr = msg->GetByteString(
+      STUN_ATTR_USERNAME);
+  ASSERT_TRUE(username_attr != NULL);
+  EXPECT_EQ("rfraglfrag", username_attr->GetString());
+  EXPECT_TRUE(msg->GetByteString(STUN_ATTR_MESSAGE_INTEGRITY) == NULL);
+  EXPECT_TRUE(msg->GetByteString(STUN_ATTR_PRIORITY) == NULL);
+  EXPECT_TRUE(msg->GetByteString(STUN_ATTR_FINGERPRINT) == NULL);
+
+  // Save a copy of the BINDING-REQUEST for use below.
+  rtc::scoped_ptr<IceMessage> request(CopyStunMessage(msg));
+
+  // Respond with a BINDING-RESPONSE.
+  rport->SendBindingResponse(request.get(), lport->Candidates()[0].address());
+  msg = rport->last_stun_msg();
+  ASSERT_TRUE(msg != NULL);
+  EXPECT_EQ(STUN_BINDING_RESPONSE, msg->type());
+  EXPECT_FALSE(msg->IsLegacy());
+  username_attr = msg->GetByteString(STUN_ATTR_USERNAME);
+  ASSERT_TRUE(username_attr != NULL);  // GICE has a username in the response.
+  EXPECT_EQ("rfraglfrag", username_attr->GetString());
+  const StunAddressAttribute* addr_attr = msg->GetAddress(
+      STUN_ATTR_MAPPED_ADDRESS);
+  ASSERT_TRUE(addr_attr != NULL);
+  EXPECT_EQ(lport->Candidates()[0].address(), addr_attr->GetAddress());
+  EXPECT_TRUE(msg->GetByteString(STUN_ATTR_XOR_MAPPED_ADDRESS) == NULL);
+  EXPECT_TRUE(msg->GetByteString(STUN_ATTR_MESSAGE_INTEGRITY) == NULL);
+  EXPECT_TRUE(msg->GetByteString(STUN_ATTR_PRIORITY) == NULL);
+  EXPECT_TRUE(msg->GetByteString(STUN_ATTR_FINGERPRINT) == NULL);
+
+  // Respond with a BINDING-ERROR-RESPONSE. This wouldn't happen in real life,
+  // but we can do it here.
+  rport->SendBindingErrorResponse(request.get(),
+                                  rport->Candidates()[0].address(),
+                                  STUN_ERROR_SERVER_ERROR,
+                                  STUN_ERROR_REASON_SERVER_ERROR);
+  msg = rport->last_stun_msg();
+  ASSERT_TRUE(msg != NULL);
+  EXPECT_EQ(STUN_BINDING_ERROR_RESPONSE, msg->type());
+  EXPECT_FALSE(msg->IsLegacy());
+  username_attr = msg->GetByteString(STUN_ATTR_USERNAME);
+  ASSERT_TRUE(username_attr != NULL);  // GICE has a username in the response.
+  EXPECT_EQ("rfraglfrag", username_attr->GetString());
+  const StunErrorCodeAttribute* error_attr = msg->GetErrorCode();
+  ASSERT_TRUE(error_attr != NULL);
+  // The GICE wire format for error codes is incorrect.
+  EXPECT_EQ(STUN_ERROR_SERVER_ERROR_AS_GICE, error_attr->code());
+  EXPECT_EQ(STUN_ERROR_SERVER_ERROR / 256, error_attr->eclass());
+  EXPECT_EQ(STUN_ERROR_SERVER_ERROR % 256, error_attr->number());
+  EXPECT_EQ(std::string(STUN_ERROR_REASON_SERVER_ERROR), error_attr->reason());
+  EXPECT_TRUE(msg->GetByteString(STUN_ATTR_PRIORITY) == NULL);
+  EXPECT_TRUE(msg->GetByteString(STUN_ATTR_MESSAGE_INTEGRITY) == NULL);
+  EXPECT_TRUE(msg->GetByteString(STUN_ATTR_FINGERPRINT) == NULL);
+}
+
+// Test sending STUN messages in ICE format.
+TEST_F(PortTest, TestSendStunMessageAsIce) {
+  rtc::scoped_ptr<TestPort> lport(
+      CreateTestPort(kLocalAddr1, "lfrag", "lpass"));
+  rtc::scoped_ptr<TestPort> rport(
+      CreateTestPort(kLocalAddr2, "rfrag", "rpass"));
+  lport->SetIceProtocolType(ICEPROTO_RFC5245);
+  lport->SetIceRole(cricket::ICEROLE_CONTROLLING);
+  lport->SetIceTiebreaker(kTiebreaker1);
+  rport->SetIceProtocolType(ICEPROTO_RFC5245);
+  rport->SetIceRole(cricket::ICEROLE_CONTROLLED);
+  rport->SetIceTiebreaker(kTiebreaker2);
+
+  // Send a fake ping from lport to rport.
+  lport->PrepareAddress();
+  rport->PrepareAddress();
+  ASSERT_FALSE(rport->Candidates().empty());
+  Connection* lconn = lport->CreateConnection(
+      rport->Candidates()[0], Port::ORIGIN_MESSAGE);
+  Connection* rconn = rport->CreateConnection(
+      lport->Candidates()[0], Port::ORIGIN_MESSAGE);
+  lconn->Ping(0);
+
+  // Check that it's a proper BINDING-REQUEST.
+  ASSERT_TRUE_WAIT(lport->last_stun_msg() != NULL, 1000);
+  IceMessage* msg = lport->last_stun_msg();
+  EXPECT_EQ(STUN_BINDING_REQUEST, msg->type());
+  EXPECT_FALSE(msg->IsLegacy());
+  const StunByteStringAttribute* username_attr =
+      msg->GetByteString(STUN_ATTR_USERNAME);
+  ASSERT_TRUE(username_attr != NULL);
+  const StunUInt32Attribute* priority_attr = msg->GetUInt32(STUN_ATTR_PRIORITY);
+  ASSERT_TRUE(priority_attr != NULL);
+  EXPECT_EQ(kDefaultPrflxPriority, priority_attr->value());
+  EXPECT_EQ("rfrag:lfrag", username_attr->GetString());
+  EXPECT_TRUE(msg->GetByteString(STUN_ATTR_MESSAGE_INTEGRITY) != NULL);
+  EXPECT_TRUE(StunMessage::ValidateMessageIntegrity(
+      lport->last_stun_buf()->Data(), lport->last_stun_buf()->Length(),
+      "rpass"));
+  const StunUInt64Attribute* ice_controlling_attr =
+      msg->GetUInt64(STUN_ATTR_ICE_CONTROLLING);
+  ASSERT_TRUE(ice_controlling_attr != NULL);
+  EXPECT_EQ(lport->IceTiebreaker(), ice_controlling_attr->value());
+  EXPECT_TRUE(msg->GetByteString(STUN_ATTR_ICE_CONTROLLED) == NULL);
+  EXPECT_TRUE(msg->GetByteString(STUN_ATTR_USE_CANDIDATE) != NULL);
+  EXPECT_TRUE(msg->GetUInt32(STUN_ATTR_FINGERPRINT) != NULL);
+  EXPECT_TRUE(StunMessage::ValidateFingerprint(
+      lport->last_stun_buf()->Data(), lport->last_stun_buf()->Length()));
+
+  // Request should not include ping count.
+  ASSERT_TRUE(msg->GetUInt32(STUN_ATTR_RETRANSMIT_COUNT) == NULL);
+
+  // Save a copy of the BINDING-REQUEST for use below.
+  rtc::scoped_ptr<IceMessage> request(CopyStunMessage(msg));
+
+  // Respond with a BINDING-RESPONSE.
+  rport->SendBindingResponse(request.get(), lport->Candidates()[0].address());
+  msg = rport->last_stun_msg();
+  ASSERT_TRUE(msg != NULL);
+  EXPECT_EQ(STUN_BINDING_RESPONSE, msg->type());
+
+
+  EXPECT_FALSE(msg->IsLegacy());
+  const StunAddressAttribute* addr_attr = msg->GetAddress(
+      STUN_ATTR_XOR_MAPPED_ADDRESS);
+  ASSERT_TRUE(addr_attr != NULL);
+  EXPECT_EQ(lport->Candidates()[0].address(), addr_attr->GetAddress());
+  EXPECT_TRUE(msg->GetByteString(STUN_ATTR_MESSAGE_INTEGRITY) != NULL);
+  EXPECT_TRUE(StunMessage::ValidateMessageIntegrity(
+      rport->last_stun_buf()->Data(), rport->last_stun_buf()->Length(),
+      "rpass"));
+  EXPECT_TRUE(msg->GetUInt32(STUN_ATTR_FINGERPRINT) != NULL);
+  EXPECT_TRUE(StunMessage::ValidateFingerprint(
+      lport->last_stun_buf()->Data(), lport->last_stun_buf()->Length()));
+  // No USERNAME or PRIORITY in ICE responses.
+  EXPECT_TRUE(msg->GetByteString(STUN_ATTR_USERNAME) == NULL);
+  EXPECT_TRUE(msg->GetByteString(STUN_ATTR_PRIORITY) == NULL);
+  EXPECT_TRUE(msg->GetByteString(STUN_ATTR_MAPPED_ADDRESS) == NULL);
+  EXPECT_TRUE(msg->GetByteString(STUN_ATTR_ICE_CONTROLLING) == NULL);
+  EXPECT_TRUE(msg->GetByteString(STUN_ATTR_ICE_CONTROLLED) == NULL);
+  EXPECT_TRUE(msg->GetByteString(STUN_ATTR_USE_CANDIDATE) == NULL);
+
+  // Response should not include ping count.
+  ASSERT_TRUE(msg->GetUInt32(STUN_ATTR_RETRANSMIT_COUNT) == NULL);
+
+  // Respond with a BINDING-ERROR-RESPONSE. This wouldn't happen in real life,
+  // but we can do it here.
+  rport->SendBindingErrorResponse(request.get(),
+                                  lport->Candidates()[0].address(),
+                                  STUN_ERROR_SERVER_ERROR,
+                                  STUN_ERROR_REASON_SERVER_ERROR);
+  msg = rport->last_stun_msg();
+  ASSERT_TRUE(msg != NULL);
+  EXPECT_EQ(STUN_BINDING_ERROR_RESPONSE, msg->type());
+  EXPECT_FALSE(msg->IsLegacy());
+  const StunErrorCodeAttribute* error_attr = msg->GetErrorCode();
+  ASSERT_TRUE(error_attr != NULL);
+  EXPECT_EQ(STUN_ERROR_SERVER_ERROR, error_attr->code());
+  EXPECT_EQ(std::string(STUN_ERROR_REASON_SERVER_ERROR), error_attr->reason());
+  EXPECT_TRUE(msg->GetByteString(STUN_ATTR_MESSAGE_INTEGRITY) != NULL);
+  EXPECT_TRUE(StunMessage::ValidateMessageIntegrity(
+      rport->last_stun_buf()->Data(), rport->last_stun_buf()->Length(),
+      "rpass"));
+  EXPECT_TRUE(msg->GetUInt32(STUN_ATTR_FINGERPRINT) != NULL);
+  EXPECT_TRUE(StunMessage::ValidateFingerprint(
+      lport->last_stun_buf()->Data(), lport->last_stun_buf()->Length()));
+  // No USERNAME with ICE.
+  EXPECT_TRUE(msg->GetByteString(STUN_ATTR_USERNAME) == NULL);
+  EXPECT_TRUE(msg->GetByteString(STUN_ATTR_PRIORITY) == NULL);
+
+  // Testing STUN binding requests from rport --> lport, having ICE_CONTROLLED
+  // and (incremented) RETRANSMIT_COUNT attributes.
+  rport->Reset();
+  rport->set_send_retransmit_count_attribute(true);
+  rconn->Ping(0);
+  rconn->Ping(0);
+  rconn->Ping(0);
+  ASSERT_TRUE_WAIT(rport->last_stun_msg() != NULL, 1000);
+  msg = rport->last_stun_msg();
+  EXPECT_EQ(STUN_BINDING_REQUEST, msg->type());
+  const StunUInt64Attribute* ice_controlled_attr =
+      msg->GetUInt64(STUN_ATTR_ICE_CONTROLLED);
+  ASSERT_TRUE(ice_controlled_attr != NULL);
+  EXPECT_EQ(rport->IceTiebreaker(), ice_controlled_attr->value());
+  EXPECT_TRUE(msg->GetByteString(STUN_ATTR_USE_CANDIDATE) == NULL);
+
+  // Request should include ping count.
+  const StunUInt32Attribute* retransmit_attr =
+      msg->GetUInt32(STUN_ATTR_RETRANSMIT_COUNT);
+  ASSERT_TRUE(retransmit_attr != NULL);
+  EXPECT_EQ(2U, retransmit_attr->value());
+
+  // Respond with a BINDING-RESPONSE.
+  request.reset(CopyStunMessage(msg));
+  lport->SendBindingResponse(request.get(), rport->Candidates()[0].address());
+  msg = lport->last_stun_msg();
+
+  // Response should include same ping count.
+  retransmit_attr = msg->GetUInt32(STUN_ATTR_RETRANSMIT_COUNT);
+  ASSERT_TRUE(retransmit_attr != NULL);
+  EXPECT_EQ(2U, retransmit_attr->value());
+}
+
+TEST_F(PortTest, TestUseCandidateAttribute) {
+  rtc::scoped_ptr<TestPort> lport(
+      CreateTestPort(kLocalAddr1, "lfrag", "lpass"));
+  rtc::scoped_ptr<TestPort> rport(
+      CreateTestPort(kLocalAddr2, "rfrag", "rpass"));
+  lport->SetIceProtocolType(ICEPROTO_RFC5245);
+  lport->SetIceRole(cricket::ICEROLE_CONTROLLING);
+  lport->SetIceTiebreaker(kTiebreaker1);
+  rport->SetIceProtocolType(ICEPROTO_RFC5245);
+  rport->SetIceRole(cricket::ICEROLE_CONTROLLED);
+  rport->SetIceTiebreaker(kTiebreaker2);
+
+  // Send a fake ping from lport to rport.
+  lport->PrepareAddress();
+  rport->PrepareAddress();
+  ASSERT_FALSE(rport->Candidates().empty());
+  Connection* lconn = lport->CreateConnection(
+      rport->Candidates()[0], Port::ORIGIN_MESSAGE);
+  lconn->Ping(0);
+  ASSERT_TRUE_WAIT(lport->last_stun_msg() != NULL, 1000);
+  IceMessage* msg = lport->last_stun_msg();
+  const StunUInt64Attribute* ice_controlling_attr =
+      msg->GetUInt64(STUN_ATTR_ICE_CONTROLLING);
+  ASSERT_TRUE(ice_controlling_attr != NULL);
+  const StunByteStringAttribute* use_candidate_attr = msg->GetByteString(
+      STUN_ATTR_USE_CANDIDATE);
+  ASSERT_TRUE(use_candidate_attr != NULL);
+}
+
+// Test handling STUN messages in GICE format.
+TEST_F(PortTest, TestHandleStunMessageAsGice) {
+  // Our port will act as the "remote" port.
+  rtc::scoped_ptr<TestPort> port(
+      CreateTestPort(kLocalAddr2, "rfrag", "rpass"));
+  port->SetIceProtocolType(ICEPROTO_GOOGLE);
+
+  rtc::scoped_ptr<IceMessage> in_msg, out_msg;
+  rtc::scoped_ptr<ByteBuffer> buf(new ByteBuffer());
+  rtc::SocketAddress addr(kLocalAddr1);
+  std::string username;
+
+  // BINDING-REQUEST from local to remote with valid GICE username and no M-I.
+  in_msg.reset(CreateStunMessageWithUsername(STUN_BINDING_REQUEST,
+                                             "rfraglfrag"));
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_TRUE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                   out_msg.accept(), &username));
+  EXPECT_TRUE(out_msg.get() != NULL);  // Succeeds, since this is GICE.
+  EXPECT_EQ("lfrag", username);
+
+  // Add M-I; should be ignored and rest of message parsed normally.
+  in_msg->AddMessageIntegrity("password");
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_TRUE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                   out_msg.accept(), &username));
+  EXPECT_TRUE(out_msg.get() != NULL);
+  EXPECT_EQ("lfrag", username);
+
+  // BINDING-RESPONSE with username, as done in GICE. Should succeed.
+  in_msg.reset(CreateStunMessageWithUsername(STUN_BINDING_RESPONSE,
+                                             "rfraglfrag"));
+  in_msg->AddAttribute(
+      new StunAddressAttribute(STUN_ATTR_MAPPED_ADDRESS, kLocalAddr2));
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_TRUE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                   out_msg.accept(), &username));
+  EXPECT_TRUE(out_msg.get() != NULL);
+  EXPECT_EQ("", username);
+
+  // BINDING-RESPONSE without username. Should be tolerated as well.
+  in_msg.reset(CreateStunMessage(STUN_BINDING_RESPONSE));
+  in_msg->AddAttribute(
+      new StunAddressAttribute(STUN_ATTR_MAPPED_ADDRESS, kLocalAddr2));
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_TRUE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                   out_msg.accept(), &username));
+  EXPECT_TRUE(out_msg.get() != NULL);
+  EXPECT_EQ("", username);
+
+  // BINDING-ERROR-RESPONSE with username and error code.
+  in_msg.reset(CreateStunMessageWithUsername(STUN_BINDING_ERROR_RESPONSE,
+                                             "rfraglfrag"));
+  in_msg->AddAttribute(new StunErrorCodeAttribute(STUN_ATTR_ERROR_CODE,
+      STUN_ERROR_SERVER_ERROR_AS_GICE, STUN_ERROR_REASON_SERVER_ERROR));
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_TRUE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                   out_msg.accept(), &username));
+  ASSERT_TRUE(out_msg.get() != NULL);
+  EXPECT_EQ("", username);
+  ASSERT_TRUE(out_msg->GetErrorCode() != NULL);
+  // GetStunMessage doesn't unmunge the GICE error code (happens downstream).
+  EXPECT_EQ(STUN_ERROR_SERVER_ERROR_AS_GICE, out_msg->GetErrorCode()->code());
+  EXPECT_EQ(std::string(STUN_ERROR_REASON_SERVER_ERROR),
+      out_msg->GetErrorCode()->reason());
+}
+
+// Test handling STUN messages in ICE format.
+TEST_F(PortTest, TestHandleStunMessageAsIce) {
+  // Our port will act as the "remote" port.
+  rtc::scoped_ptr<TestPort> port(
+      CreateTestPort(kLocalAddr2, "rfrag", "rpass"));
+  port->SetIceProtocolType(ICEPROTO_RFC5245);
+
+  rtc::scoped_ptr<IceMessage> in_msg, out_msg;
+  rtc::scoped_ptr<ByteBuffer> buf(new ByteBuffer());
+  rtc::SocketAddress addr(kLocalAddr1);
+  std::string username;
+
+  // BINDING-REQUEST from local to remote with valid ICE username,
+  // MESSAGE-INTEGRITY, and FINGERPRINT.
+  in_msg.reset(CreateStunMessageWithUsername(STUN_BINDING_REQUEST,
+                                             "rfrag:lfrag"));
+  in_msg->AddMessageIntegrity("rpass");
+  in_msg->AddFingerprint();
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_TRUE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                   out_msg.accept(), &username));
+  EXPECT_TRUE(out_msg.get() != NULL);
+  EXPECT_EQ("lfrag", username);
+
+  // BINDING-RESPONSE without username, with MESSAGE-INTEGRITY and FINGERPRINT.
+  in_msg.reset(CreateStunMessage(STUN_BINDING_RESPONSE));
+  in_msg->AddAttribute(
+      new StunXorAddressAttribute(STUN_ATTR_XOR_MAPPED_ADDRESS, kLocalAddr2));
+  in_msg->AddMessageIntegrity("rpass");
+  in_msg->AddFingerprint();
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_TRUE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                   out_msg.accept(), &username));
+  EXPECT_TRUE(out_msg.get() != NULL);
+  EXPECT_EQ("", username);
+
+  // BINDING-ERROR-RESPONSE without username, with error, M-I, and FINGERPRINT.
+  in_msg.reset(CreateStunMessage(STUN_BINDING_ERROR_RESPONSE));
+  in_msg->AddAttribute(new StunErrorCodeAttribute(STUN_ATTR_ERROR_CODE,
+      STUN_ERROR_SERVER_ERROR, STUN_ERROR_REASON_SERVER_ERROR));
+  in_msg->AddFingerprint();
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_TRUE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                   out_msg.accept(), &username));
+  EXPECT_TRUE(out_msg.get() != NULL);
+  EXPECT_EQ("", username);
+  ASSERT_TRUE(out_msg->GetErrorCode() != NULL);
+  EXPECT_EQ(STUN_ERROR_SERVER_ERROR, out_msg->GetErrorCode()->code());
+  EXPECT_EQ(std::string(STUN_ERROR_REASON_SERVER_ERROR),
+      out_msg->GetErrorCode()->reason());
+}
+
+// This test verifies port can handle ICE messages in Hybrid mode and switches
+// ICEPROTO_RFC5245 mode after successfully handling the message.
+TEST_F(PortTest, TestHandleStunMessageAsIceInHybridMode) {
+  // Our port will act as the "remote" port.
+  rtc::scoped_ptr<TestPort> port(
+      CreateTestPort(kLocalAddr2, "rfrag", "rpass"));
+  port->SetIceProtocolType(ICEPROTO_HYBRID);
+
+  rtc::scoped_ptr<IceMessage> in_msg, out_msg;
+  rtc::scoped_ptr<ByteBuffer> buf(new ByteBuffer());
+  rtc::SocketAddress addr(kLocalAddr1);
+  std::string username;
+
+  // BINDING-REQUEST from local to remote with valid ICE username,
+  // MESSAGE-INTEGRITY, and FINGERPRINT.
+  in_msg.reset(CreateStunMessageWithUsername(STUN_BINDING_REQUEST,
+                                             "rfrag:lfrag"));
+  in_msg->AddMessageIntegrity("rpass");
+  in_msg->AddFingerprint();
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_TRUE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                   out_msg.accept(), &username));
+  EXPECT_TRUE(out_msg.get() != NULL);
+  EXPECT_EQ("lfrag", username);
+  EXPECT_EQ(ICEPROTO_RFC5245, port->IceProtocol());
+}
+
+// This test verifies port can handle GICE messages in Hybrid mode and switches
+// ICEPROTO_GOOGLE mode after successfully handling the message.
+TEST_F(PortTest, TestHandleStunMessageAsGiceInHybridMode) {
+  // Our port will act as the "remote" port.
+  rtc::scoped_ptr<TestPort> port(
+      CreateTestPort(kLocalAddr2, "rfrag", "rpass"));
+  port->SetIceProtocolType(ICEPROTO_HYBRID);
+
+  rtc::scoped_ptr<IceMessage> in_msg, out_msg;
+  rtc::scoped_ptr<ByteBuffer> buf(new ByteBuffer());
+  rtc::SocketAddress addr(kLocalAddr1);
+  std::string username;
+
+  // BINDING-REQUEST from local to remote with valid GICE username and no M-I.
+  in_msg.reset(CreateStunMessageWithUsername(STUN_BINDING_REQUEST,
+                                             "rfraglfrag"));
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_TRUE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                   out_msg.accept(), &username));
+  EXPECT_TRUE(out_msg.get() != NULL);  // Succeeds, since this is GICE.
+  EXPECT_EQ("lfrag", username);
+  EXPECT_EQ(ICEPROTO_GOOGLE, port->IceProtocol());
+}
+
+// Verify port is not switched out of RFC5245 mode if GICE message is received
+// in that mode.
+TEST_F(PortTest, TestHandleStunMessageAsGiceInIceMode) {
+  // Our port will act as the "remote" port.
+  rtc::scoped_ptr<TestPort> port(
+      CreateTestPort(kLocalAddr2, "rfrag", "rpass"));
+  port->SetIceProtocolType(ICEPROTO_RFC5245);
+
+  rtc::scoped_ptr<IceMessage> in_msg, out_msg;
+  rtc::scoped_ptr<ByteBuffer> buf(new ByteBuffer());
+  rtc::SocketAddress addr(kLocalAddr1);
+  std::string username;
+
+  // BINDING-REQUEST from local to remote with valid GICE username and no M-I.
+  in_msg.reset(CreateStunMessageWithUsername(STUN_BINDING_REQUEST,
+                                             "rfraglfrag"));
+  WriteStunMessage(in_msg.get(), buf.get());
+  // Should fail as there is no MI and fingerprint.
+  EXPECT_FALSE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                    out_msg.accept(), &username));
+  EXPECT_EQ(ICEPROTO_RFC5245, port->IceProtocol());
+}
+
+
+// Tests handling of GICE binding requests with missing or incorrect usernames.
+TEST_F(PortTest, TestHandleStunMessageAsGiceBadUsername) {
+  rtc::scoped_ptr<TestPort> port(
+      CreateTestPort(kLocalAddr2, "rfrag", "rpass"));
+  port->SetIceProtocolType(ICEPROTO_GOOGLE);
+
+  rtc::scoped_ptr<IceMessage> in_msg, out_msg;
+  rtc::scoped_ptr<ByteBuffer> buf(new ByteBuffer());
+  rtc::SocketAddress addr(kLocalAddr1);
+  std::string username;
+
+  // BINDING-REQUEST with no username.
+  in_msg.reset(CreateStunMessage(STUN_BINDING_REQUEST));
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_TRUE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                   out_msg.accept(), &username));
+  EXPECT_TRUE(out_msg.get() == NULL);
+  EXPECT_EQ("", username);
+  EXPECT_EQ(STUN_ERROR_BAD_REQUEST_AS_GICE, port->last_stun_error_code());
+
+  // BINDING-REQUEST with empty username.
+  in_msg.reset(CreateStunMessageWithUsername(STUN_BINDING_REQUEST, ""));
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_TRUE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                   out_msg.accept(), &username));
+  EXPECT_TRUE(out_msg.get() == NULL);
+  EXPECT_EQ("", username);
+  EXPECT_EQ(STUN_ERROR_UNAUTHORIZED_AS_GICE, port->last_stun_error_code());
+
+  // BINDING-REQUEST with too-short username.
+  in_msg.reset(CreateStunMessageWithUsername(STUN_BINDING_REQUEST, "lfra"));
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_TRUE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                   out_msg.accept(), &username));
+  EXPECT_TRUE(out_msg.get() == NULL);
+  EXPECT_EQ("", username);
+  EXPECT_EQ(STUN_ERROR_UNAUTHORIZED_AS_GICE, port->last_stun_error_code());
+
+  // BINDING-REQUEST with reversed username.
+  in_msg.reset(CreateStunMessageWithUsername(STUN_BINDING_REQUEST,
+                                             "lfragrfrag"));
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_TRUE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                   out_msg.accept(), &username));
+  EXPECT_TRUE(out_msg.get() == NULL);
+  EXPECT_EQ("", username);
+  EXPECT_EQ(STUN_ERROR_UNAUTHORIZED_AS_GICE, port->last_stun_error_code());
+
+  // BINDING-REQUEST with garbage username.
+  in_msg.reset(CreateStunMessageWithUsername(STUN_BINDING_REQUEST,
+                                             "abcdefgh"));
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_TRUE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                   out_msg.accept(), &username));
+  EXPECT_TRUE(out_msg.get() == NULL);
+  EXPECT_EQ("", username);
+  EXPECT_EQ(STUN_ERROR_UNAUTHORIZED_AS_GICE, port->last_stun_error_code());
+}
+
+// Tests handling of ICE binding requests with missing or incorrect usernames.
+TEST_F(PortTest, TestHandleStunMessageAsIceBadUsername) {
+  rtc::scoped_ptr<TestPort> port(
+      CreateTestPort(kLocalAddr2, "rfrag", "rpass"));
+  port->SetIceProtocolType(ICEPROTO_RFC5245);
+
+  rtc::scoped_ptr<IceMessage> in_msg, out_msg;
+  rtc::scoped_ptr<ByteBuffer> buf(new ByteBuffer());
+  rtc::SocketAddress addr(kLocalAddr1);
+  std::string username;
+
+  // BINDING-REQUEST with no username.
+  in_msg.reset(CreateStunMessage(STUN_BINDING_REQUEST));
+  in_msg->AddMessageIntegrity("rpass");
+  in_msg->AddFingerprint();
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_TRUE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                   out_msg.accept(), &username));
+  EXPECT_TRUE(out_msg.get() == NULL);
+  EXPECT_EQ("", username);
+  EXPECT_EQ(STUN_ERROR_BAD_REQUEST, port->last_stun_error_code());
+
+  // BINDING-REQUEST with empty username.
+  in_msg.reset(CreateStunMessageWithUsername(STUN_BINDING_REQUEST, ""));
+  in_msg->AddMessageIntegrity("rpass");
+  in_msg->AddFingerprint();
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_TRUE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                   out_msg.accept(), &username));
+  EXPECT_TRUE(out_msg.get() == NULL);
+  EXPECT_EQ("", username);
+  EXPECT_EQ(STUN_ERROR_UNAUTHORIZED, port->last_stun_error_code());
+
+  // BINDING-REQUEST with too-short username.
+  in_msg.reset(CreateStunMessageWithUsername(STUN_BINDING_REQUEST, "rfra"));
+  in_msg->AddMessageIntegrity("rpass");
+  in_msg->AddFingerprint();
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_TRUE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                   out_msg.accept(), &username));
+  EXPECT_TRUE(out_msg.get() == NULL);
+  EXPECT_EQ("", username);
+  EXPECT_EQ(STUN_ERROR_UNAUTHORIZED, port->last_stun_error_code());
+
+  // BINDING-REQUEST with reversed username.
+  in_msg.reset(CreateStunMessageWithUsername(STUN_BINDING_REQUEST,
+                                            "lfrag:rfrag"));
+  in_msg->AddMessageIntegrity("rpass");
+  in_msg->AddFingerprint();
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_TRUE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                   out_msg.accept(), &username));
+  EXPECT_TRUE(out_msg.get() == NULL);
+  EXPECT_EQ("", username);
+  EXPECT_EQ(STUN_ERROR_UNAUTHORIZED, port->last_stun_error_code());
+
+  // BINDING-REQUEST with garbage username.
+  in_msg.reset(CreateStunMessageWithUsername(STUN_BINDING_REQUEST,
+                                             "abcd:efgh"));
+  in_msg->AddMessageIntegrity("rpass");
+  in_msg->AddFingerprint();
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_TRUE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                   out_msg.accept(), &username));
+  EXPECT_TRUE(out_msg.get() == NULL);
+  EXPECT_EQ("", username);
+  EXPECT_EQ(STUN_ERROR_UNAUTHORIZED, port->last_stun_error_code());
+}
+
+// Test handling STUN messages (as ICE) with missing or malformed M-I.
+TEST_F(PortTest, TestHandleStunMessageAsIceBadMessageIntegrity) {
+  // Our port will act as the "remote" port.
+  rtc::scoped_ptr<TestPort> port(
+      CreateTestPort(kLocalAddr2, "rfrag", "rpass"));
+  port->SetIceProtocolType(ICEPROTO_RFC5245);
+
+  rtc::scoped_ptr<IceMessage> in_msg, out_msg;
+  rtc::scoped_ptr<ByteBuffer> buf(new ByteBuffer());
+  rtc::SocketAddress addr(kLocalAddr1);
+  std::string username;
+
+  // BINDING-REQUEST from local to remote with valid ICE username and
+  // FINGERPRINT, but no MESSAGE-INTEGRITY.
+  in_msg.reset(CreateStunMessageWithUsername(STUN_BINDING_REQUEST,
+                                             "rfrag:lfrag"));
+  in_msg->AddFingerprint();
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_TRUE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                   out_msg.accept(), &username));
+  EXPECT_TRUE(out_msg.get() == NULL);
+  EXPECT_EQ("", username);
+  EXPECT_EQ(STUN_ERROR_BAD_REQUEST, port->last_stun_error_code());
+
+  // BINDING-REQUEST from local to remote with valid ICE username and
+  // FINGERPRINT, but invalid MESSAGE-INTEGRITY.
+  in_msg.reset(CreateStunMessageWithUsername(STUN_BINDING_REQUEST,
+                                             "rfrag:lfrag"));
+  in_msg->AddMessageIntegrity("invalid");
+  in_msg->AddFingerprint();
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_TRUE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                   out_msg.accept(), &username));
+  EXPECT_TRUE(out_msg.get() == NULL);
+  EXPECT_EQ("", username);
+  EXPECT_EQ(STUN_ERROR_UNAUTHORIZED, port->last_stun_error_code());
+
+  // TODO: BINDING-RESPONSES and BINDING-ERROR-RESPONSES are checked
+  // by the Connection, not the Port, since they require the remote username.
+  // Change this test to pass in data via Connection::OnReadPacket instead.
+}
+
+// Test handling STUN messages (as ICE) with missing or malformed FINGERPRINT.
+TEST_F(PortTest, TestHandleStunMessageAsIceBadFingerprint) {
+  // Our port will act as the "remote" port.
+  rtc::scoped_ptr<TestPort> port(
+      CreateTestPort(kLocalAddr2, "rfrag", "rpass"));
+  port->SetIceProtocolType(ICEPROTO_RFC5245);
+
+  rtc::scoped_ptr<IceMessage> in_msg, out_msg;
+  rtc::scoped_ptr<ByteBuffer> buf(new ByteBuffer());
+  rtc::SocketAddress addr(kLocalAddr1);
+  std::string username;
+
+  // BINDING-REQUEST from local to remote with valid ICE username and
+  // MESSAGE-INTEGRITY, but no FINGERPRINT; GetStunMessage should fail.
+  in_msg.reset(CreateStunMessageWithUsername(STUN_BINDING_REQUEST,
+                                             "rfrag:lfrag"));
+  in_msg->AddMessageIntegrity("rpass");
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_FALSE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                    out_msg.accept(), &username));
+  EXPECT_EQ(0, port->last_stun_error_code());
+
+  // Now, add a fingerprint, but munge the message so it's not valid.
+  in_msg->AddFingerprint();
+  in_msg->SetTransactionID("TESTTESTBADD");
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_FALSE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                    out_msg.accept(), &username));
+  EXPECT_EQ(0, port->last_stun_error_code());
+
+  // Valid BINDING-RESPONSE, except no FINGERPRINT.
+  in_msg.reset(CreateStunMessage(STUN_BINDING_RESPONSE));
+  in_msg->AddAttribute(
+      new StunXorAddressAttribute(STUN_ATTR_XOR_MAPPED_ADDRESS, kLocalAddr2));
+  in_msg->AddMessageIntegrity("rpass");
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_FALSE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                    out_msg.accept(), &username));
+  EXPECT_EQ(0, port->last_stun_error_code());
+
+  // Now, add a fingerprint, but munge the message so it's not valid.
+  in_msg->AddFingerprint();
+  in_msg->SetTransactionID("TESTTESTBADD");
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_FALSE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                    out_msg.accept(), &username));
+  EXPECT_EQ(0, port->last_stun_error_code());
+
+  // Valid BINDING-ERROR-RESPONSE, except no FINGERPRINT.
+  in_msg.reset(CreateStunMessage(STUN_BINDING_ERROR_RESPONSE));
+  in_msg->AddAttribute(new StunErrorCodeAttribute(STUN_ATTR_ERROR_CODE,
+      STUN_ERROR_SERVER_ERROR, STUN_ERROR_REASON_SERVER_ERROR));
+  in_msg->AddMessageIntegrity("rpass");
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_FALSE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                    out_msg.accept(), &username));
+  EXPECT_EQ(0, port->last_stun_error_code());
+
+  // Now, add a fingerprint, but munge the message so it's not valid.
+  in_msg->AddFingerprint();
+  in_msg->SetTransactionID("TESTTESTBADD");
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_FALSE(port->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                    out_msg.accept(), &username));
+  EXPECT_EQ(0, port->last_stun_error_code());
+}
+
+// Test handling of STUN binding indication messages (as ICE). STUN binding
+// indications are allowed only to the connection which is in read mode.
+TEST_F(PortTest, TestHandleStunBindingIndication) {
+  rtc::scoped_ptr<TestPort> lport(
+      CreateTestPort(kLocalAddr2, "lfrag", "lpass"));
+  lport->SetIceProtocolType(ICEPROTO_RFC5245);
+  lport->SetIceRole(cricket::ICEROLE_CONTROLLING);
+  lport->SetIceTiebreaker(kTiebreaker1);
+
+  // Verifying encoding and decoding STUN indication message.
+  rtc::scoped_ptr<IceMessage> in_msg, out_msg;
+  rtc::scoped_ptr<ByteBuffer> buf(new ByteBuffer());
+  rtc::SocketAddress addr(kLocalAddr1);
+  std::string username;
+
+  in_msg.reset(CreateStunMessage(STUN_BINDING_INDICATION));
+  in_msg->AddFingerprint();
+  WriteStunMessage(in_msg.get(), buf.get());
+  EXPECT_TRUE(lport->GetStunMessage(buf->Data(), buf->Length(), addr,
+                                    out_msg.accept(), &username));
+  EXPECT_TRUE(out_msg.get() != NULL);
+  EXPECT_EQ(out_msg->type(), STUN_BINDING_INDICATION);
+  EXPECT_EQ("", username);
+
+  // Verify connection can handle STUN indication and updates
+  // last_ping_received.
+  rtc::scoped_ptr<TestPort> rport(
+      CreateTestPort(kLocalAddr2, "rfrag", "rpass"));
+  rport->SetIceProtocolType(ICEPROTO_RFC5245);
+  rport->SetIceRole(cricket::ICEROLE_CONTROLLED);
+  rport->SetIceTiebreaker(kTiebreaker2);
+
+  lport->PrepareAddress();
+  rport->PrepareAddress();
+  ASSERT_FALSE(lport->Candidates().empty());
+  ASSERT_FALSE(rport->Candidates().empty());
+
+  Connection* lconn = lport->CreateConnection(rport->Candidates()[0],
+                                              Port::ORIGIN_MESSAGE);
+  Connection* rconn = rport->CreateConnection(lport->Candidates()[0],
+                                              Port::ORIGIN_MESSAGE);
+  rconn->Ping(0);
+
+  ASSERT_TRUE_WAIT(rport->last_stun_msg() != NULL, 1000);
+  IceMessage* msg = rport->last_stun_msg();
+  EXPECT_EQ(STUN_BINDING_REQUEST, msg->type());
+  // Send rport binding request to lport.
+  lconn->OnReadPacket(rport->last_stun_buf()->Data(),
+                      rport->last_stun_buf()->Length(),
+                      rtc::PacketTime());
+  ASSERT_TRUE_WAIT(lport->last_stun_msg() != NULL, 1000);
+  EXPECT_EQ(STUN_BINDING_RESPONSE, lport->last_stun_msg()->type());
+  uint32 last_ping_received1 = lconn->last_ping_received();
+
+  // Adding a delay of 100ms.
+  rtc::Thread::Current()->ProcessMessages(100);
+  // Pinging lconn using stun indication message.
+  lconn->OnReadPacket(buf->Data(), buf->Length(), rtc::PacketTime());
+  uint32 last_ping_received2 = lconn->last_ping_received();
+  EXPECT_GT(last_ping_received2, last_ping_received1);
+}
+
+TEST_F(PortTest, TestComputeCandidatePriority) {
+  rtc::scoped_ptr<TestPort> port(
+      CreateTestPort(kLocalAddr1, "name", "pass"));
+  port->set_type_preference(90);
+  port->set_component(177);
+  port->AddCandidateAddress(SocketAddress("192.168.1.4", 1234));
+  port->AddCandidateAddress(SocketAddress("2001:db8::1234", 1234));
+  port->AddCandidateAddress(SocketAddress("fc12:3456::1234", 1234));
+  port->AddCandidateAddress(SocketAddress("::ffff:192.168.1.4", 1234));
+  port->AddCandidateAddress(SocketAddress("::192.168.1.4", 1234));
+  port->AddCandidateAddress(SocketAddress("2002::1234:5678", 1234));
+  port->AddCandidateAddress(SocketAddress("2001::1234:5678", 1234));
+  port->AddCandidateAddress(SocketAddress("fecf::1234:5678", 1234));
+  port->AddCandidateAddress(SocketAddress("3ffe::1234:5678", 1234));
+  // These should all be:
+  // (90 << 24) | ([rfc3484 pref value] << 8) | (256 - 177)
+  uint32 expected_priority_v4 = 1509957199U;
+  uint32 expected_priority_v6 = 1509959759U;
+  uint32 expected_priority_ula = 1509962319U;
+  uint32 expected_priority_v4mapped = expected_priority_v4;
+  uint32 expected_priority_v4compat = 1509949775U;
+  uint32 expected_priority_6to4 = 1509954639U;
+  uint32 expected_priority_teredo = 1509952079U;
+  uint32 expected_priority_sitelocal = 1509949775U;
+  uint32 expected_priority_6bone = 1509949775U;
+  ASSERT_EQ(expected_priority_v4, port->Candidates()[0].priority());
+  ASSERT_EQ(expected_priority_v6, port->Candidates()[1].priority());
+  ASSERT_EQ(expected_priority_ula, port->Candidates()[2].priority());
+  ASSERT_EQ(expected_priority_v4mapped, port->Candidates()[3].priority());
+  ASSERT_EQ(expected_priority_v4compat, port->Candidates()[4].priority());
+  ASSERT_EQ(expected_priority_6to4, port->Candidates()[5].priority());
+  ASSERT_EQ(expected_priority_teredo, port->Candidates()[6].priority());
+  ASSERT_EQ(expected_priority_sitelocal, port->Candidates()[7].priority());
+  ASSERT_EQ(expected_priority_6bone, port->Candidates()[8].priority());
+}
+
+TEST_F(PortTest, TestPortProxyProperties) {
+  rtc::scoped_ptr<TestPort> port(
+      CreateTestPort(kLocalAddr1, "name", "pass"));
+  port->SetIceRole(cricket::ICEROLE_CONTROLLING);
+  port->SetIceTiebreaker(kTiebreaker1);
+
+  // Create a proxy port.
+  rtc::scoped_ptr<PortProxy> proxy(new PortProxy());
+  proxy->set_impl(port.get());
+  EXPECT_EQ(port->Type(), proxy->Type());
+  EXPECT_EQ(port->Network(), proxy->Network());
+  EXPECT_EQ(port->GetIceRole(), proxy->GetIceRole());
+  EXPECT_EQ(port->IceTiebreaker(), proxy->IceTiebreaker());
+}
+
+// In the case of shared socket, one port may be shared by local and stun.
+// Test that candidates with different types will have different foundation.
+TEST_F(PortTest, TestFoundation) {
+  rtc::scoped_ptr<TestPort> testport(
+      CreateTestPort(kLocalAddr1, "name", "pass"));
+  testport->AddCandidateAddress(kLocalAddr1, kLocalAddr1,
+                                LOCAL_PORT_TYPE,
+                                cricket::ICE_TYPE_PREFERENCE_HOST, false);
+  testport->AddCandidateAddress(kLocalAddr2, kLocalAddr1,
+                                STUN_PORT_TYPE,
+                                cricket::ICE_TYPE_PREFERENCE_SRFLX, true);
+  EXPECT_NE(testport->Candidates()[0].foundation(),
+            testport->Candidates()[1].foundation());
+}
+
+// This test verifies the foundation of different types of ICE candidates.
+TEST_F(PortTest, TestCandidateFoundation) {
+  rtc::scoped_ptr<rtc::NATServer> nat_server(
+      CreateNatServer(kNatAddr1, NAT_OPEN_CONE));
+  rtc::scoped_ptr<UDPPort> udpport1(CreateUdpPort(kLocalAddr1));
+  udpport1->PrepareAddress();
+  rtc::scoped_ptr<UDPPort> udpport2(CreateUdpPort(kLocalAddr1));
+  udpport2->PrepareAddress();
+  EXPECT_EQ(udpport1->Candidates()[0].foundation(),
+            udpport2->Candidates()[0].foundation());
+  rtc::scoped_ptr<TCPPort> tcpport1(CreateTcpPort(kLocalAddr1));
+  tcpport1->PrepareAddress();
+  rtc::scoped_ptr<TCPPort> tcpport2(CreateTcpPort(kLocalAddr1));
+  tcpport2->PrepareAddress();
+  EXPECT_EQ(tcpport1->Candidates()[0].foundation(),
+            tcpport2->Candidates()[0].foundation());
+  rtc::scoped_ptr<Port> stunport(
+      CreateStunPort(kLocalAddr1, nat_socket_factory1()));
+  stunport->PrepareAddress();
+  ASSERT_EQ_WAIT(1U, stunport->Candidates().size(), kTimeout);
+  EXPECT_NE(tcpport1->Candidates()[0].foundation(),
+            stunport->Candidates()[0].foundation());
+  EXPECT_NE(tcpport2->Candidates()[0].foundation(),
+            stunport->Candidates()[0].foundation());
+  EXPECT_NE(udpport1->Candidates()[0].foundation(),
+            stunport->Candidates()[0].foundation());
+  EXPECT_NE(udpport2->Candidates()[0].foundation(),
+            stunport->Candidates()[0].foundation());
+  // Verify GTURN candidate foundation.
+  rtc::scoped_ptr<RelayPort> relayport(
+      CreateGturnPort(kLocalAddr1));
+  relayport->AddServerAddress(
+      cricket::ProtocolAddress(kRelayUdpIntAddr, cricket::PROTO_UDP));
+  relayport->PrepareAddress();
+  ASSERT_EQ_WAIT(1U, relayport->Candidates().size(), kTimeout);
+  EXPECT_NE(udpport1->Candidates()[0].foundation(),
+            relayport->Candidates()[0].foundation());
+  EXPECT_NE(udpport2->Candidates()[0].foundation(),
+            relayport->Candidates()[0].foundation());
+  // Verifying TURN candidate foundation.
+  rtc::scoped_ptr<Port> turnport1(CreateTurnPort(
+      kLocalAddr1, nat_socket_factory1(), PROTO_UDP, PROTO_UDP));
+  turnport1->PrepareAddress();
+  ASSERT_EQ_WAIT(1U, turnport1->Candidates().size(), kTimeout);
+  EXPECT_NE(udpport1->Candidates()[0].foundation(),
+            turnport1->Candidates()[0].foundation());
+  EXPECT_NE(udpport2->Candidates()[0].foundation(),
+            turnport1->Candidates()[0].foundation());
+  EXPECT_NE(stunport->Candidates()[0].foundation(),
+            turnport1->Candidates()[0].foundation());
+  rtc::scoped_ptr<Port> turnport2(CreateTurnPort(
+      kLocalAddr1, nat_socket_factory1(), PROTO_UDP, PROTO_UDP));
+  turnport2->PrepareAddress();
+  ASSERT_EQ_WAIT(1U, turnport2->Candidates().size(), kTimeout);
+  EXPECT_EQ(turnport1->Candidates()[0].foundation(),
+            turnport2->Candidates()[0].foundation());
+
+  // Running a second turn server, to get different base IP address.
+  SocketAddress kTurnUdpIntAddr2("99.99.98.4", STUN_SERVER_PORT);
+  SocketAddress kTurnUdpExtAddr2("99.99.98.5", 0);
+  TestTurnServer turn_server2(
+      rtc::Thread::Current(), kTurnUdpIntAddr2, kTurnUdpExtAddr2);
+  rtc::scoped_ptr<Port> turnport3(CreateTurnPort(
+      kLocalAddr1, nat_socket_factory1(), PROTO_UDP, PROTO_UDP,
+      kTurnUdpIntAddr2));
+  turnport3->PrepareAddress();
+  ASSERT_EQ_WAIT(1U, turnport3->Candidates().size(), kTimeout);
+  EXPECT_NE(turnport3->Candidates()[0].foundation(),
+            turnport2->Candidates()[0].foundation());
+}
+
+// This test verifies the related addresses of different types of
+// ICE candiates.
+TEST_F(PortTest, TestCandidateRelatedAddress) {
+  rtc::scoped_ptr<rtc::NATServer> nat_server(
+      CreateNatServer(kNatAddr1, NAT_OPEN_CONE));
+  rtc::scoped_ptr<UDPPort> udpport(CreateUdpPort(kLocalAddr1));
+  udpport->PrepareAddress();
+  // For UDPPort, related address will be empty.
+  EXPECT_TRUE(udpport->Candidates()[0].related_address().IsNil());
+  // Testing related address for stun candidates.
+  // For stun candidate related address must be equal to the base
+  // socket address.
+  rtc::scoped_ptr<StunPort> stunport(
+      CreateStunPort(kLocalAddr1, nat_socket_factory1()));
+  stunport->PrepareAddress();
+  ASSERT_EQ_WAIT(1U, stunport->Candidates().size(), kTimeout);
+  // Check STUN candidate address.
+  EXPECT_EQ(stunport->Candidates()[0].address().ipaddr(),
+            kNatAddr1.ipaddr());
+  // Check STUN candidate related address.
+  EXPECT_EQ(stunport->Candidates()[0].related_address(),
+            stunport->GetLocalAddress());
+  // Verifying the related address for the GTURN candidates.
+  // NOTE: In case of GTURN related address will be equal to the mapped
+  // address, but address(mapped) will not be XOR.
+  rtc::scoped_ptr<RelayPort> relayport(
+      CreateGturnPort(kLocalAddr1));
+  relayport->AddServerAddress(
+      cricket::ProtocolAddress(kRelayUdpIntAddr, cricket::PROTO_UDP));
+  relayport->PrepareAddress();
+  ASSERT_EQ_WAIT(1U, relayport->Candidates().size(), kTimeout);
+  // For Gturn related address is set to "0.0.0.0:0"
+  EXPECT_EQ(rtc::SocketAddress(),
+            relayport->Candidates()[0].related_address());
+  // Verifying the related address for TURN candidate.
+  // For TURN related address must be equal to the mapped address.
+  rtc::scoped_ptr<Port> turnport(CreateTurnPort(
+      kLocalAddr1, nat_socket_factory1(), PROTO_UDP, PROTO_UDP));
+  turnport->PrepareAddress();
+  ASSERT_EQ_WAIT(1U, turnport->Candidates().size(), kTimeout);
+  EXPECT_EQ(kTurnUdpExtAddr.ipaddr(),
+            turnport->Candidates()[0].address().ipaddr());
+  EXPECT_EQ(kNatAddr1.ipaddr(),
+            turnport->Candidates()[0].related_address().ipaddr());
+}
+
+// Test priority value overflow handling when preference is set to 3.
+TEST_F(PortTest, TestCandidatePreference) {
+  cricket::Candidate cand1;
+  cand1.set_preference(3);
+  cricket::Candidate cand2;
+  cand2.set_preference(1);
+  EXPECT_TRUE(cand1.preference() > cand2.preference());
+}
+
+// Test the Connection priority is calculated correctly.
+TEST_F(PortTest, TestConnectionPriority) {
+  rtc::scoped_ptr<TestPort> lport(
+      CreateTestPort(kLocalAddr1, "lfrag", "lpass"));
+  lport->set_type_preference(cricket::ICE_TYPE_PREFERENCE_HOST);
+  rtc::scoped_ptr<TestPort> rport(
+      CreateTestPort(kLocalAddr2, "rfrag", "rpass"));
+  rport->set_type_preference(cricket::ICE_TYPE_PREFERENCE_RELAY);
+  lport->set_component(123);
+  lport->AddCandidateAddress(SocketAddress("192.168.1.4", 1234));
+  rport->set_component(23);
+  rport->AddCandidateAddress(SocketAddress("10.1.1.100", 1234));
+
+  EXPECT_EQ(0x7E001E85U, lport->Candidates()[0].priority());
+  EXPECT_EQ(0x2001EE9U, rport->Candidates()[0].priority());
+
+  // RFC 5245
+  // pair priority = 2^32*MIN(G,D) + 2*MAX(G,D) + (G>D?1:0)
+  lport->SetIceRole(cricket::ICEROLE_CONTROLLING);
+  rport->SetIceRole(cricket::ICEROLE_CONTROLLED);
+  Connection* lconn = lport->CreateConnection(
+      rport->Candidates()[0], Port::ORIGIN_MESSAGE);
+#if defined(WEBRTC_WIN)
+  EXPECT_EQ(0x2001EE9FC003D0BU, lconn->priority());
+#else
+  EXPECT_EQ(0x2001EE9FC003D0BLLU, lconn->priority());
+#endif
+
+  lport->SetIceRole(cricket::ICEROLE_CONTROLLED);
+  rport->SetIceRole(cricket::ICEROLE_CONTROLLING);
+  Connection* rconn = rport->CreateConnection(
+      lport->Candidates()[0], Port::ORIGIN_MESSAGE);
+#if defined(WEBRTC_WIN)
+  EXPECT_EQ(0x2001EE9FC003D0AU, rconn->priority());
+#else
+  EXPECT_EQ(0x2001EE9FC003D0ALLU, rconn->priority());
+#endif
+}
+
+TEST_F(PortTest, TestWritableState) {
+  UDPPort* port1 = CreateUdpPort(kLocalAddr1);
+  UDPPort* port2 = CreateUdpPort(kLocalAddr2);
+
+  // Set up channels.
+  TestChannel ch1(port1, port2);
+  TestChannel ch2(port2, port1);
+
+  // Acquire addresses.
+  ch1.Start();
+  ch2.Start();
+  ASSERT_EQ_WAIT(1, ch1.complete_count(), kTimeout);
+  ASSERT_EQ_WAIT(1, ch2.complete_count(), kTimeout);
+
+  // Send a ping from src to dst.
+  ch1.CreateConnection();
+  ASSERT_TRUE(ch1.conn() != NULL);
+  EXPECT_EQ(Connection::STATE_WRITE_INIT, ch1.conn()->write_state());
+  EXPECT_TRUE_WAIT(ch1.conn()->connected(), kTimeout);  // for TCP connect
+  ch1.Ping();
+  WAIT(!ch2.remote_address().IsNil(), kTimeout);
+
+  // Data should be unsendable until the connection is accepted.
+  char data[] = "abcd";
+  int data_size = ARRAY_SIZE(data);
+  rtc::PacketOptions options;
+  EXPECT_EQ(SOCKET_ERROR, ch1.conn()->Send(data, data_size, options));
+
+  // Accept the connection to return the binding response, transition to
+  // writable, and allow data to be sent.
+  ch2.AcceptConnection();
+  EXPECT_EQ_WAIT(Connection::STATE_WRITABLE, ch1.conn()->write_state(),
+                 kTimeout);
+  EXPECT_EQ(data_size, ch1.conn()->Send(data, data_size, options));
+
+  // Ask the connection to update state as if enough time has passed to lose
+  // full writability and 5 pings went unresponded to. We'll accomplish the
+  // latter by sending pings but not pumping messages.
+  for (uint32 i = 1; i <= CONNECTION_WRITE_CONNECT_FAILURES; ++i) {
+    ch1.Ping(i);
+  }
+  uint32 unreliable_timeout_delay = CONNECTION_WRITE_CONNECT_TIMEOUT + 500u;
+  ch1.conn()->UpdateState(unreliable_timeout_delay);
+  EXPECT_EQ(Connection::STATE_WRITE_UNRELIABLE, ch1.conn()->write_state());
+
+  // Data should be able to be sent in this state.
+  EXPECT_EQ(data_size, ch1.conn()->Send(data, data_size, options));
+
+  // And now allow the other side to process the pings and send binding
+  // responses.
+  EXPECT_EQ_WAIT(Connection::STATE_WRITABLE, ch1.conn()->write_state(),
+                 kTimeout);
+
+  // Wait long enough for a full timeout (past however long we've already
+  // waited).
+  for (uint32 i = 1; i <= CONNECTION_WRITE_CONNECT_FAILURES; ++i) {
+    ch1.Ping(unreliable_timeout_delay + i);
+  }
+  ch1.conn()->UpdateState(unreliable_timeout_delay + CONNECTION_WRITE_TIMEOUT +
+                          500u);
+  EXPECT_EQ(Connection::STATE_WRITE_TIMEOUT, ch1.conn()->write_state());
+
+  // Now that the connection has completely timed out, data send should fail.
+  EXPECT_EQ(SOCKET_ERROR, ch1.conn()->Send(data, data_size, options));
+
+  ch1.Stop();
+  ch2.Stop();
+}
+
+TEST_F(PortTest, TestTimeoutForNeverWritable) {
+  UDPPort* port1 = CreateUdpPort(kLocalAddr1);
+  UDPPort* port2 = CreateUdpPort(kLocalAddr2);
+
+  // Set up channels.
+  TestChannel ch1(port1, port2);
+  TestChannel ch2(port2, port1);
+
+  // Acquire addresses.
+  ch1.Start();
+  ch2.Start();
+
+  ch1.CreateConnection();
+  ASSERT_TRUE(ch1.conn() != NULL);
+  EXPECT_EQ(Connection::STATE_WRITE_INIT, ch1.conn()->write_state());
+
+  // Attempt to go directly to write timeout.
+  for (uint32 i = 1; i <= CONNECTION_WRITE_CONNECT_FAILURES; ++i) {
+    ch1.Ping(i);
+  }
+  ch1.conn()->UpdateState(CONNECTION_WRITE_TIMEOUT + 500u);
+  EXPECT_EQ(Connection::STATE_WRITE_TIMEOUT, ch1.conn()->write_state());
+}
+
+// This test verifies the connection setup between ICEMODE_FULL
+// and ICEMODE_LITE.
+// In this test |ch1| behaves like FULL mode client and we have created
+// port which responds to the ping message just like LITE client.
+TEST_F(PortTest, TestIceLiteConnectivity) {
+  TestPort* ice_full_port = CreateTestPort(
+      kLocalAddr1, "lfrag", "lpass", cricket::ICEPROTO_RFC5245,
+      cricket::ICEROLE_CONTROLLING, kTiebreaker1);
+
+  rtc::scoped_ptr<TestPort> ice_lite_port(CreateTestPort(
+      kLocalAddr2, "rfrag", "rpass", cricket::ICEPROTO_RFC5245,
+      cricket::ICEROLE_CONTROLLED, kTiebreaker2));
+  // Setup TestChannel. This behaves like FULL mode client.
+  TestChannel ch1(ice_full_port, ice_lite_port.get());
+  ch1.SetIceMode(ICEMODE_FULL);
+
+  // Start gathering candidates.
+  ch1.Start();
+  ice_lite_port->PrepareAddress();
+
+  ASSERT_EQ_WAIT(1, ch1.complete_count(), kTimeout);
+  ASSERT_FALSE(ice_lite_port->Candidates().empty());
+
+  ch1.CreateConnection();
+  ASSERT_TRUE(ch1.conn() != NULL);
+  EXPECT_EQ(Connection::STATE_WRITE_INIT, ch1.conn()->write_state());
+
+  // Send ping from full mode client.
+  // This ping must not have USE_CANDIDATE_ATTR.
+  ch1.Ping();
+
+  // Verify stun ping is without USE_CANDIDATE_ATTR. Getting message directly
+  // from port.
+  ASSERT_TRUE_WAIT(ice_full_port->last_stun_msg() != NULL, 1000);
+  IceMessage* msg = ice_full_port->last_stun_msg();
+  EXPECT_TRUE(msg->GetByteString(STUN_ATTR_USE_CANDIDATE) == NULL);
+
+  // Respond with a BINDING-RESPONSE from litemode client.
+  // NOTE: Ideally we should't create connection at this stage from lite
+  // port, as it should be done only after receiving ping with USE_CANDIDATE.
+  // But we need a connection to send a response message.
+  ice_lite_port->CreateConnection(
+      ice_full_port->Candidates()[0], cricket::Port::ORIGIN_MESSAGE);
+  rtc::scoped_ptr<IceMessage> request(CopyStunMessage(msg));
+  ice_lite_port->SendBindingResponse(
+      request.get(), ice_full_port->Candidates()[0].address());
+
+  // Feeding the respone message from litemode to the full mode connection.
+  ch1.conn()->OnReadPacket(ice_lite_port->last_stun_buf()->Data(),
+                           ice_lite_port->last_stun_buf()->Length(),
+                           rtc::PacketTime());
+  // Verifying full mode connection becomes writable from the response.
+  EXPECT_EQ_WAIT(Connection::STATE_WRITABLE, ch1.conn()->write_state(),
+                 kTimeout);
+  EXPECT_TRUE_WAIT(ch1.nominated(), kTimeout);
+
+  // Clear existing stun messsages. Otherwise we will process old stun
+  // message right after we send ping.
+  ice_full_port->Reset();
+  // Send ping. This must have USE_CANDIDATE_ATTR.
+  ch1.Ping();
+  ASSERT_TRUE_WAIT(ice_full_port->last_stun_msg() != NULL, 1000);
+  msg = ice_full_port->last_stun_msg();
+  EXPECT_TRUE(msg->GetByteString(STUN_ATTR_USE_CANDIDATE) != NULL);
+  ch1.Stop();
+}
+
+// This test case verifies that the CONTROLLING port does not time out.
+TEST_F(PortTest, TestControllingNoTimeout) {
+  SetIceProtocolType(cricket::ICEPROTO_RFC5245);
+  UDPPort* port1 = CreateUdpPort(kLocalAddr1);
+  ConnectToSignalDestroyed(port1);
+  port1->set_timeout_delay(10);  // milliseconds
+  port1->SetIceRole(cricket::ICEROLE_CONTROLLING);
+  port1->SetIceTiebreaker(kTiebreaker1);
+
+  UDPPort* port2 = CreateUdpPort(kLocalAddr2);
+  port2->SetIceRole(cricket::ICEROLE_CONTROLLED);
+  port2->SetIceTiebreaker(kTiebreaker2);
+
+  // Set up channels and ensure both ports will be deleted.
+  TestChannel ch1(port1, port2);
+  TestChannel ch2(port2, port1);
+
+  // Simulate a connection that succeeds, and then is destroyed.
+  ConnectAndDisconnectChannels(&ch1, &ch2);
+
+  // After the connection is destroyed, the port should not be destroyed.
+  rtc::Thread::Current()->ProcessMessages(kTimeout);
+  EXPECT_FALSE(destroyed());
+}
+
+// This test case verifies that the CONTROLLED port does time out, but only
+// after connectivity is lost.
+TEST_F(PortTest, TestControlledTimeout) {
+  SetIceProtocolType(cricket::ICEPROTO_RFC5245);
+  UDPPort* port1 = CreateUdpPort(kLocalAddr1);
+  port1->SetIceRole(cricket::ICEROLE_CONTROLLING);
+  port1->SetIceTiebreaker(kTiebreaker1);
+
+  UDPPort* port2 = CreateUdpPort(kLocalAddr2);
+  ConnectToSignalDestroyed(port2);
+  port2->set_timeout_delay(10);  // milliseconds
+  port2->SetIceRole(cricket::ICEROLE_CONTROLLED);
+  port2->SetIceTiebreaker(kTiebreaker2);
+
+  // The connection must not be destroyed before a connection is attempted.
+  EXPECT_FALSE(destroyed());
+
+  port1->set_component(cricket::ICE_CANDIDATE_COMPONENT_DEFAULT);
+  port2->set_component(cricket::ICE_CANDIDATE_COMPONENT_DEFAULT);
+
+  // Set up channels and ensure both ports will be deleted.
+  TestChannel ch1(port1, port2);
+  TestChannel ch2(port2, port1);
+
+  // Simulate a connection that succeeds, and then is destroyed.
+  ConnectAndDisconnectChannels(&ch1, &ch2);
+
+  // The controlled port should be destroyed after 10 milliseconds.
+  EXPECT_TRUE_WAIT(destroyed(), kTimeout);
+}
diff --git a/webrtc/p2p/base/portallocator.cc b/webrtc/p2p/base/portallocator.cc
new file mode 100644
index 0000000..8613347
--- /dev/null
+++ b/webrtc/p2p/base/portallocator.cc
@@ -0,0 +1,92 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/portallocator.h"
+
+#include "webrtc/p2p/base/portallocatorsessionproxy.h"
+
+namespace cricket {
+
+PortAllocatorSession::PortAllocatorSession(const std::string& content_name,
+                                           int component,
+                                           const std::string& ice_ufrag,
+                                           const std::string& ice_pwd,
+                                           uint32 flags)
+    : content_name_(content_name),
+      component_(component),
+      flags_(flags),
+      generation_(0),
+      // If PORTALLOCATOR_ENABLE_SHARED_UFRAG flag is not enabled, ignore the
+      // incoming ufrag and pwd, which will cause each Port to generate one
+      // by itself.
+      username_(flags_ & PORTALLOCATOR_ENABLE_SHARED_UFRAG ? ice_ufrag : ""),
+      password_(flags_ & PORTALLOCATOR_ENABLE_SHARED_UFRAG ? ice_pwd : "") {
+}
+
+PortAllocator::~PortAllocator() {
+  for (SessionMuxerMap::iterator iter = muxers_.begin();
+       iter != muxers_.end(); ++iter) {
+    delete iter->second;
+  }
+}
+
+PortAllocatorSession* PortAllocator::CreateSession(
+    const std::string& sid,
+    const std::string& content_name,
+    int component,
+    const std::string& ice_ufrag,
+    const std::string& ice_pwd) {
+  if (flags_ & PORTALLOCATOR_ENABLE_BUNDLE) {
+    // If we just use |sid| as key in identifying PortAllocatorSessionMuxer,
+    // ICE restart will not result in different candidates, as |sid| will
+    // be same. To yield different candiates we are using combination of
+    // |ice_ufrag| and |ice_pwd|.
+    // Ideally |ice_ufrag| and |ice_pwd| should change together, but
+    // there can be instances where only ice_pwd will be changed.
+    std::string key_str = ice_ufrag + ":" + ice_pwd;
+    PortAllocatorSessionMuxer* muxer = GetSessionMuxer(key_str);
+    if (!muxer) {
+      PortAllocatorSession* session_impl = CreateSessionInternal(
+          content_name, component, ice_ufrag, ice_pwd);
+      // Create PortAllocatorSessionMuxer object for |session_impl|.
+      muxer = new PortAllocatorSessionMuxer(session_impl);
+      muxer->SignalDestroyed.connect(
+          this, &PortAllocator::OnSessionMuxerDestroyed);
+      // Add PortAllocatorSession to the map.
+      muxers_[key_str] = muxer;
+    }
+    PortAllocatorSessionProxy* proxy =
+        new PortAllocatorSessionProxy(content_name, component, flags_);
+    muxer->RegisterSessionProxy(proxy);
+    return proxy;
+  }
+  return CreateSessionInternal(content_name, component, ice_ufrag, ice_pwd);
+}
+
+PortAllocatorSessionMuxer* PortAllocator::GetSessionMuxer(
+    const std::string& key) const {
+  SessionMuxerMap::const_iterator iter = muxers_.find(key);
+  if (iter != muxers_.end())
+    return iter->second;
+  return NULL;
+}
+
+void PortAllocator::OnSessionMuxerDestroyed(
+    PortAllocatorSessionMuxer* session) {
+  SessionMuxerMap::iterator iter;
+  for (iter = muxers_.begin(); iter != muxers_.end(); ++iter) {
+    if (iter->second == session)
+      break;
+  }
+  if (iter != muxers_.end())
+    muxers_.erase(iter);
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/portallocator.h b/webrtc/p2p/base/portallocator.h
new file mode 100644
index 0000000..65aab44
--- /dev/null
+++ b/webrtc/p2p/base/portallocator.h
@@ -0,0 +1,192 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_PORTALLOCATOR_H_
+#define WEBRTC_P2P_BASE_PORTALLOCATOR_H_
+
+#include <string>
+#include <vector>
+
+#include "webrtc/p2p/base/portinterface.h"
+#include "webrtc/base/helpers.h"
+#include "webrtc/base/proxyinfo.h"
+#include "webrtc/base/sigslot.h"
+
+namespace cricket {
+
+// PortAllocator is responsible for allocating Port types for a given
+// P2PSocket. It also handles port freeing.
+//
+// Clients can override this class to control port allocation, including
+// what kinds of ports are allocated.
+
+enum {
+  PORTALLOCATOR_DISABLE_UDP = 0x01,
+  PORTALLOCATOR_DISABLE_STUN = 0x02,
+  PORTALLOCATOR_DISABLE_RELAY = 0x04,
+  PORTALLOCATOR_DISABLE_TCP = 0x08,
+  PORTALLOCATOR_ENABLE_SHAKER = 0x10,
+  PORTALLOCATOR_ENABLE_BUNDLE = 0x20,
+  PORTALLOCATOR_ENABLE_IPV6 = 0x40,
+  PORTALLOCATOR_ENABLE_SHARED_UFRAG = 0x80,
+  PORTALLOCATOR_ENABLE_SHARED_SOCKET = 0x100,
+  PORTALLOCATOR_ENABLE_STUN_RETRANSMIT_ATTRIBUTE = 0x200,
+};
+
+const uint32 kDefaultPortAllocatorFlags = 0;
+
+const uint32 kDefaultStepDelay = 1000;  // 1 sec step delay.
+// As per RFC 5245 Appendix B.1, STUN transactions need to be paced at certain
+// internal. Less than 20ms is not acceptable. We choose 50ms as our default.
+const uint32 kMinimumStepDelay = 50;
+
+// CF = CANDIDATE FILTER
+enum {
+  CF_NONE = 0x0,
+  CF_HOST = 0x1,
+  CF_REFLEXIVE = 0x2,
+  CF_RELAY = 0x4,
+  CF_ALL = 0x7,
+};
+
+class PortAllocatorSessionMuxer;
+
+class PortAllocatorSession : public sigslot::has_slots<> {
+ public:
+  // Content name passed in mostly for logging and debugging.
+  // TODO(mallinath) - Change username and password to ice_ufrag and ice_pwd.
+  PortAllocatorSession(const std::string& content_name,
+                       int component,
+                       const std::string& username,
+                       const std::string& password,
+                       uint32 flags);
+
+  // Subclasses should clean up any ports created.
+  virtual ~PortAllocatorSession() {}
+
+  uint32 flags() const { return flags_; }
+  void set_flags(uint32 flags) { flags_ = flags; }
+  std::string content_name() const { return content_name_; }
+  int component() const { return component_; }
+
+  // Starts gathering STUN and Relay configurations.
+  virtual void StartGettingPorts() = 0;
+  virtual void StopGettingPorts() = 0;
+  virtual bool IsGettingPorts() = 0;
+
+  sigslot::signal2<PortAllocatorSession*, PortInterface*> SignalPortReady;
+  sigslot::signal2<PortAllocatorSession*,
+                   const std::vector<Candidate>&> SignalCandidatesReady;
+  sigslot::signal1<PortAllocatorSession*> SignalCandidatesAllocationDone;
+
+  virtual uint32 generation() { return generation_; }
+  virtual void set_generation(uint32 generation) { generation_ = generation; }
+  sigslot::signal1<PortAllocatorSession*> SignalDestroyed;
+
+ protected:
+  const std::string& username() const { return username_; }
+  const std::string& password() const { return password_; }
+
+  std::string content_name_;
+  int component_;
+
+ private:
+  uint32 flags_;
+  uint32 generation_;
+  std::string username_;
+  std::string password_;
+};
+
+class PortAllocator : public sigslot::has_slots<> {
+ public:
+  PortAllocator() :
+      flags_(kDefaultPortAllocatorFlags),
+      min_port_(0),
+      max_port_(0),
+      step_delay_(kDefaultStepDelay),
+      allow_tcp_listen_(true),
+      candidate_filter_(CF_ALL) {
+    // This will allow us to have old behavior on non webrtc clients.
+  }
+  virtual ~PortAllocator();
+
+  PortAllocatorSession* CreateSession(
+      const std::string& sid,
+      const std::string& content_name,
+      int component,
+      const std::string& ice_ufrag,
+      const std::string& ice_pwd);
+
+  PortAllocatorSessionMuxer* GetSessionMuxer(const std::string& key) const;
+  void OnSessionMuxerDestroyed(PortAllocatorSessionMuxer* session);
+
+  uint32 flags() const { return flags_; }
+  void set_flags(uint32 flags) { flags_ = flags; }
+
+  const std::string& user_agent() const { return agent_; }
+  const rtc::ProxyInfo& proxy() const { return proxy_; }
+  void set_proxy(const std::string& agent, const rtc::ProxyInfo& proxy) {
+    agent_ = agent;
+    proxy_ = proxy;
+  }
+
+  // Gets/Sets the port range to use when choosing client ports.
+  int min_port() const { return min_port_; }
+  int max_port() const { return max_port_; }
+  bool SetPortRange(int min_port, int max_port) {
+    if (min_port > max_port) {
+      return false;
+    }
+
+    min_port_ = min_port;
+    max_port_ = max_port;
+    return true;
+  }
+
+  uint32 step_delay() const { return step_delay_; }
+  void set_step_delay(uint32 delay) {
+    step_delay_ = delay;
+  }
+
+  bool allow_tcp_listen() const { return allow_tcp_listen_; }
+  void set_allow_tcp_listen(bool allow_tcp_listen) {
+    allow_tcp_listen_ = allow_tcp_listen;
+  }
+
+  uint32 candidate_filter() { return candidate_filter_; }
+  bool set_candidate_filter(uint32 filter) {
+    // TODO(mallinath) - Do transition check?
+    candidate_filter_ = filter;
+    return true;
+  }
+
+ protected:
+  virtual PortAllocatorSession* CreateSessionInternal(
+      const std::string& content_name,
+      int component,
+      const std::string& ice_ufrag,
+      const std::string& ice_pwd) = 0;
+
+  typedef std::map<std::string, PortAllocatorSessionMuxer*> SessionMuxerMap;
+
+  uint32 flags_;
+  std::string agent_;
+  rtc::ProxyInfo proxy_;
+  int min_port_;
+  int max_port_;
+  uint32 step_delay_;
+  SessionMuxerMap muxers_;
+  bool allow_tcp_listen_;
+  uint32 candidate_filter_;
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_PORTALLOCATOR_H_
diff --git a/webrtc/p2p/base/portallocatorsessionproxy.cc b/webrtc/p2p/base/portallocatorsessionproxy.cc
new file mode 100644
index 0000000..f5ce9a4
--- /dev/null
+++ b/webrtc/p2p/base/portallocatorsessionproxy.cc
@@ -0,0 +1,222 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/portallocatorsessionproxy.h"
+
+#include "webrtc/p2p/base/portallocator.h"
+#include "webrtc/p2p/base/portproxy.h"
+#include "webrtc/base/thread.h"
+
+namespace cricket {
+
+enum {
+  MSG_SEND_ALLOCATION_DONE = 1,
+  MSG_SEND_ALLOCATED_PORTS,
+};
+
+typedef rtc::TypedMessageData<PortAllocatorSessionProxy*> ProxyObjData;
+
+PortAllocatorSessionMuxer::PortAllocatorSessionMuxer(
+    PortAllocatorSession* session)
+    : worker_thread_(rtc::Thread::Current()),
+      session_(session),
+      candidate_done_signal_received_(false) {
+  session_->SignalPortReady.connect(
+      this, &PortAllocatorSessionMuxer::OnPortReady);
+  session_->SignalCandidatesAllocationDone.connect(
+      this, &PortAllocatorSessionMuxer::OnCandidatesAllocationDone);
+}
+
+PortAllocatorSessionMuxer::~PortAllocatorSessionMuxer() {
+  for (size_t i = 0; i < session_proxies_.size(); ++i)
+    delete session_proxies_[i];
+
+  SignalDestroyed(this);
+}
+
+void PortAllocatorSessionMuxer::RegisterSessionProxy(
+    PortAllocatorSessionProxy* session_proxy) {
+  session_proxies_.push_back(session_proxy);
+  session_proxy->SignalDestroyed.connect(
+      this, &PortAllocatorSessionMuxer::OnSessionProxyDestroyed);
+  session_proxy->set_impl(session_.get());
+
+  // Populate new proxy session with the information available in the actual
+  // implementation.
+  if (!ports_.empty()) {
+    worker_thread_->Post(
+        this, MSG_SEND_ALLOCATED_PORTS, new ProxyObjData(session_proxy));
+  }
+
+  if (candidate_done_signal_received_) {
+    worker_thread_->Post(
+        this, MSG_SEND_ALLOCATION_DONE, new ProxyObjData(session_proxy));
+  }
+}
+
+void PortAllocatorSessionMuxer::OnCandidatesAllocationDone(
+    PortAllocatorSession* session) {
+  candidate_done_signal_received_ = true;
+}
+
+void PortAllocatorSessionMuxer::OnPortReady(PortAllocatorSession* session,
+                                            PortInterface* port) {
+  ASSERT(session == session_.get());
+  ports_.push_back(port);
+  port->SignalDestroyed.connect(
+      this, &PortAllocatorSessionMuxer::OnPortDestroyed);
+}
+
+void PortAllocatorSessionMuxer::OnPortDestroyed(PortInterface* port) {
+  std::vector<PortInterface*>::iterator it =
+      std::find(ports_.begin(), ports_.end(), port);
+  if (it != ports_.end())
+    ports_.erase(it);
+}
+
+void PortAllocatorSessionMuxer::OnSessionProxyDestroyed(
+    PortAllocatorSession* proxy) {
+
+  std::vector<PortAllocatorSessionProxy*>::iterator it =
+      std::find(session_proxies_.begin(), session_proxies_.end(), proxy);
+  if (it != session_proxies_.end()) {
+    session_proxies_.erase(it);
+  }
+
+  if (session_proxies_.empty()) {
+    // Destroy PortAllocatorSession and its associated muxer object if all
+    // proxies belonging to this session are already destroyed.
+    delete this;
+  }
+}
+
+void PortAllocatorSessionMuxer::OnMessage(rtc::Message *pmsg) {
+  ProxyObjData* proxy = static_cast<ProxyObjData*>(pmsg->pdata);
+  switch (pmsg->message_id) {
+    case MSG_SEND_ALLOCATION_DONE:
+      SendAllocationDone_w(proxy->data());
+      delete proxy;
+      break;
+    case MSG_SEND_ALLOCATED_PORTS:
+      SendAllocatedPorts_w(proxy->data());
+      delete proxy;
+      break;
+    default:
+      ASSERT(false);
+      break;
+  }
+}
+
+void PortAllocatorSessionMuxer::SendAllocationDone_w(
+    PortAllocatorSessionProxy* proxy) {
+  std::vector<PortAllocatorSessionProxy*>::iterator iter =
+      std::find(session_proxies_.begin(), session_proxies_.end(), proxy);
+  if (iter != session_proxies_.end()) {
+    proxy->OnCandidatesAllocationDone(session_.get());
+  }
+}
+
+void PortAllocatorSessionMuxer::SendAllocatedPorts_w(
+    PortAllocatorSessionProxy* proxy) {
+  std::vector<PortAllocatorSessionProxy*>::iterator iter =
+      std::find(session_proxies_.begin(), session_proxies_.end(), proxy);
+  if (iter != session_proxies_.end()) {
+    for (size_t i = 0; i < ports_.size(); ++i) {
+      PortInterface* port = ports_[i];
+      proxy->OnPortReady(session_.get(), port);
+      // If port already has candidates, send this to the clients of proxy
+      // session. This can happen if proxy is created later than the actual
+      // implementation.
+      if (!port->Candidates().empty()) {
+        proxy->OnCandidatesReady(session_.get(), port->Candidates());
+      }
+    }
+  }
+}
+
+PortAllocatorSessionProxy::~PortAllocatorSessionProxy() {
+  std::map<PortInterface*, PortProxy*>::iterator it;
+  for (it = proxy_ports_.begin(); it != proxy_ports_.end(); it++)
+    delete it->second;
+
+  SignalDestroyed(this);
+}
+
+void PortAllocatorSessionProxy::set_impl(
+    PortAllocatorSession* session) {
+  impl_ = session;
+
+  impl_->SignalCandidatesReady.connect(
+      this, &PortAllocatorSessionProxy::OnCandidatesReady);
+  impl_->SignalPortReady.connect(
+      this, &PortAllocatorSessionProxy::OnPortReady);
+  impl_->SignalCandidatesAllocationDone.connect(
+      this, &PortAllocatorSessionProxy::OnCandidatesAllocationDone);
+}
+
+void PortAllocatorSessionProxy::StartGettingPorts() {
+  ASSERT(impl_ != NULL);
+  // Since all proxies share a common PortAllocatorSession, this check will
+  // prohibit sending multiple STUN ping messages to the stun server, which
+  // is a problem on Chrome. GetInitialPorts() and StartGetAllPorts() called
+  // from the worker thread and are called together from TransportChannel,
+  // checking for IsGettingAllPorts() for GetInitialPorts() will not be a
+  // problem.
+  if (!impl_->IsGettingPorts()) {
+    impl_->StartGettingPorts();
+  }
+}
+
+void PortAllocatorSessionProxy::StopGettingPorts() {
+  ASSERT(impl_ != NULL);
+  if (impl_->IsGettingPorts()) {
+    impl_->StopGettingPorts();
+  }
+}
+
+bool PortAllocatorSessionProxy::IsGettingPorts() {
+  ASSERT(impl_ != NULL);
+  return impl_->IsGettingPorts();
+}
+
+void PortAllocatorSessionProxy::OnPortReady(PortAllocatorSession* session,
+                                            PortInterface* port) {
+  ASSERT(session == impl_);
+
+  PortProxy* proxy_port = new PortProxy();
+  proxy_port->set_impl(port);
+  proxy_ports_[port] = proxy_port;
+  SignalPortReady(this, proxy_port);
+}
+
+void PortAllocatorSessionProxy::OnCandidatesReady(
+    PortAllocatorSession* session,
+    const std::vector<Candidate>& candidates) {
+  ASSERT(session == impl_);
+
+  // Since all proxy sessions share a common PortAllocatorSession,
+  // all Candidates will have name associated with the common PAS.
+  // Change Candidate name with the PortAllocatorSessionProxy name.
+  std::vector<Candidate> our_candidates;
+  for (size_t i = 0; i < candidates.size(); ++i) {
+    Candidate new_local_candidate = candidates[i];
+    new_local_candidate.set_component(component_);
+    our_candidates.push_back(new_local_candidate);
+  }
+  SignalCandidatesReady(this, our_candidates);
+}
+
+void PortAllocatorSessionProxy::OnCandidatesAllocationDone(
+    PortAllocatorSession* session) {
+  ASSERT(session == impl_);
+  SignalCandidatesAllocationDone(this);
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/portallocatorsessionproxy.h b/webrtc/p2p/base/portallocatorsessionproxy.h
new file mode 100644
index 0000000..94ae19d
--- /dev/null
+++ b/webrtc/p2p/base/portallocatorsessionproxy.h
@@ -0,0 +1,106 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_PORTALLOCATORSESSIONPROXY_H_
+#define WEBRTC_P2P_BASE_PORTALLOCATORSESSIONPROXY_H_
+
+#include <string>
+
+#include "webrtc/p2p/base/candidate.h"
+#include "webrtc/p2p/base/portallocator.h"
+
+namespace cricket {
+class PortAllocator;
+class PortAllocatorSessionProxy;
+class PortProxy;
+
+// This class maintains the list of cricket::Port* objects. Ports will be
+// deleted upon receiving SignalDestroyed signal. This class is used when
+// PORTALLOCATOR_ENABLE_BUNDLE flag is set.
+
+class PortAllocatorSessionMuxer : public rtc::MessageHandler,
+                                  public sigslot::has_slots<> {
+ public:
+  explicit PortAllocatorSessionMuxer(PortAllocatorSession* session);
+  virtual ~PortAllocatorSessionMuxer();
+
+  void RegisterSessionProxy(PortAllocatorSessionProxy* session_proxy);
+
+  void OnPortReady(PortAllocatorSession* session, PortInterface* port);
+  void OnPortDestroyed(PortInterface* port);
+  void OnCandidatesAllocationDone(PortAllocatorSession* session);
+
+  const std::vector<PortInterface*>& ports() { return ports_; }
+
+  sigslot::signal1<PortAllocatorSessionMuxer*> SignalDestroyed;
+
+ private:
+  virtual void OnMessage(rtc::Message *pmsg);
+  void OnSessionProxyDestroyed(PortAllocatorSession* proxy);
+  void SendAllocationDone_w(PortAllocatorSessionProxy* proxy);
+  void SendAllocatedPorts_w(PortAllocatorSessionProxy* proxy);
+
+  // Port will be deleted when SignalDestroyed received, otherwise delete
+  // happens when PortAllocatorSession dtor is called.
+  rtc::Thread* worker_thread_;
+  std::vector<PortInterface*> ports_;
+  rtc::scoped_ptr<PortAllocatorSession> session_;
+  std::vector<PortAllocatorSessionProxy*> session_proxies_;
+  bool candidate_done_signal_received_;
+};
+
+class PortAllocatorSessionProxy : public PortAllocatorSession {
+ public:
+  PortAllocatorSessionProxy(const std::string& content_name,
+                            int component,
+                            uint32 flags)
+        // Use empty string as the ufrag and pwd because the proxy always uses
+        // the ufrag and pwd from the underlying implementation.
+      : PortAllocatorSession(content_name, component, "", "", flags),
+        impl_(NULL) {
+  }
+
+  virtual ~PortAllocatorSessionProxy();
+
+  PortAllocatorSession* impl() { return impl_; }
+  void set_impl(PortAllocatorSession* session);
+
+  // Forwards call to the actual PortAllocatorSession.
+  virtual void StartGettingPorts();
+  virtual void StopGettingPorts();
+  virtual bool IsGettingPorts();
+
+  virtual void set_generation(uint32 generation) {
+    ASSERT(impl_ != NULL);
+    impl_->set_generation(generation);
+  }
+
+  virtual uint32 generation() {
+    ASSERT(impl_ != NULL);
+    return impl_->generation();
+  }
+
+ private:
+  void OnPortReady(PortAllocatorSession* session, PortInterface* port);
+  void OnCandidatesReady(PortAllocatorSession* session,
+                         const std::vector<Candidate>& candidates);
+  void OnPortDestroyed(PortInterface* port);
+  void OnCandidatesAllocationDone(PortAllocatorSession* session);
+
+  // This is the actual PortAllocatorSession, owned by PortAllocator.
+  PortAllocatorSession* impl_;
+  std::map<PortInterface*, PortProxy*> proxy_ports_;
+
+  friend class PortAllocatorSessionMuxer;
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_PORTALLOCATORSESSIONPROXY_H_
diff --git a/webrtc/p2p/base/portallocatorsessionproxy_unittest.cc b/webrtc/p2p/base/portallocatorsessionproxy_unittest.cc
new file mode 100644
index 0000000..61a9e98
--- /dev/null
+++ b/webrtc/p2p/base/portallocatorsessionproxy_unittest.cc
@@ -0,0 +1,146 @@
+/*
+ *  Copyright 2012 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <vector>
+
+#include "webrtc/p2p/base/basicpacketsocketfactory.h"
+#include "webrtc/p2p/base/portallocatorsessionproxy.h"
+#include "webrtc/p2p/client/basicportallocator.h"
+#include "webrtc/p2p/client/fakeportallocator.h"
+#include "webrtc/base/fakenetwork.h"
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/thread.h"
+
+using cricket::Candidate;
+using cricket::PortAllocatorSession;
+using cricket::PortAllocatorSessionMuxer;
+using cricket::PortAllocatorSessionProxy;
+
+// Based on ICE_UFRAG_LENGTH
+static const char kIceUfrag0[] = "TESTICEUFRAG0000";
+// Based on ICE_PWD_LENGTH
+static const char kIcePwd0[] = "TESTICEPWD00000000000000";
+
+class TestSessionChannel : public sigslot::has_slots<> {
+ public:
+  explicit TestSessionChannel(PortAllocatorSessionProxy* proxy)
+      : proxy_session_(proxy),
+        candidates_count_(0),
+        allocation_complete_(false),
+        ports_count_(0) {
+    proxy_session_->SignalCandidatesAllocationDone.connect(
+        this, &TestSessionChannel::OnCandidatesAllocationDone);
+    proxy_session_->SignalCandidatesReady.connect(
+        this, &TestSessionChannel::OnCandidatesReady);
+    proxy_session_->SignalPortReady.connect(
+        this, &TestSessionChannel::OnPortReady);
+  }
+  virtual ~TestSessionChannel() {
+    delete proxy_session_;
+  }
+  void OnCandidatesReady(PortAllocatorSession* session,
+                         const std::vector<Candidate>& candidates) {
+    EXPECT_EQ(proxy_session_, session);
+    candidates_count_ += static_cast<int>(candidates.size());
+  }
+  void OnCandidatesAllocationDone(PortAllocatorSession* session) {
+    EXPECT_EQ(proxy_session_, session);
+    allocation_complete_ = true;
+  }
+  void OnPortReady(PortAllocatorSession* session,
+                   cricket::PortInterface* port) {
+    EXPECT_EQ(proxy_session_, session);
+    ++ports_count_;
+  }
+  int candidates_count() { return candidates_count_; }
+  bool allocation_complete() { return allocation_complete_; }
+  int ports_count() { return ports_count_; }
+
+  void StartGettingPorts() {
+    proxy_session_->StartGettingPorts();
+  }
+
+  void StopGettingPorts() {
+    proxy_session_->StopGettingPorts();
+  }
+
+  bool IsGettingPorts() {
+    return proxy_session_->IsGettingPorts();
+  }
+
+ private:
+  PortAllocatorSessionProxy* proxy_session_;
+  int candidates_count_;
+  bool allocation_complete_;
+  int ports_count_;
+};
+
+class PortAllocatorSessionProxyTest : public testing::Test {
+ public:
+  PortAllocatorSessionProxyTest()
+      : socket_factory_(rtc::Thread::Current()),
+        allocator_(rtc::Thread::Current(), NULL),
+        session_(new cricket::FakePortAllocatorSession(
+                     rtc::Thread::Current(), &socket_factory_,
+                     "test content", 1,
+                     kIceUfrag0, kIcePwd0)),
+        session_muxer_(new PortAllocatorSessionMuxer(session_)) {
+  }
+  virtual ~PortAllocatorSessionProxyTest() {}
+  void RegisterSessionProxy(PortAllocatorSessionProxy* proxy) {
+    session_muxer_->RegisterSessionProxy(proxy);
+  }
+
+  TestSessionChannel* CreateChannel() {
+    PortAllocatorSessionProxy* proxy =
+        new PortAllocatorSessionProxy("test content", 1, 0);
+    TestSessionChannel* channel = new TestSessionChannel(proxy);
+    session_muxer_->RegisterSessionProxy(proxy);
+    channel->StartGettingPorts();
+    return channel;
+  }
+
+ protected:
+  rtc::BasicPacketSocketFactory socket_factory_;
+  cricket::FakePortAllocator allocator_;
+  cricket::FakePortAllocatorSession* session_;
+  // Muxer object will be delete itself after all registered session proxies
+  // are deleted.
+  PortAllocatorSessionMuxer* session_muxer_;
+};
+
+TEST_F(PortAllocatorSessionProxyTest, TestBasic) {
+  TestSessionChannel* channel = CreateChannel();
+  EXPECT_EQ_WAIT(1, channel->candidates_count(), 1000);
+  EXPECT_EQ(1, channel->ports_count());
+  EXPECT_TRUE(channel->allocation_complete());
+  delete channel;
+}
+
+TEST_F(PortAllocatorSessionProxyTest, TestLateBinding) {
+  TestSessionChannel* channel1 = CreateChannel();
+  EXPECT_EQ_WAIT(1, channel1->candidates_count(), 1000);
+  EXPECT_EQ(1, channel1->ports_count());
+  EXPECT_TRUE(channel1->allocation_complete());
+  EXPECT_EQ(1, session_->port_config_count());
+  // Creating another PortAllocatorSessionProxy and it also should receive
+  // already happened events.
+  PortAllocatorSessionProxy* proxy =
+      new PortAllocatorSessionProxy("test content", 2, 0);
+  TestSessionChannel* channel2 = new TestSessionChannel(proxy);
+  session_muxer_->RegisterSessionProxy(proxy);
+  EXPECT_TRUE(channel2->IsGettingPorts());
+  EXPECT_EQ_WAIT(1, channel2->candidates_count(), 1000);
+  EXPECT_EQ(1, channel2->ports_count());
+  EXPECT_TRUE_WAIT(channel2->allocation_complete(), 1000);
+  EXPECT_EQ(1, session_->port_config_count());
+  delete channel1;
+  delete channel2;
+}
diff --git a/webrtc/p2p/base/portinterface.h b/webrtc/p2p/base/portinterface.h
new file mode 100644
index 0000000..ee6835e
--- /dev/null
+++ b/webrtc/p2p/base/portinterface.h
@@ -0,0 +1,126 @@
+/*
+ *  Copyright 2012 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_PORTINTERFACE_H_
+#define WEBRTC_P2P_BASE_PORTINTERFACE_H_
+
+#include <string>
+
+#include "webrtc/p2p/base/transport.h"
+#include "webrtc/base/socketaddress.h"
+
+namespace rtc {
+class Network;
+struct PacketOptions;
+}
+
+namespace cricket {
+class Connection;
+class IceMessage;
+class StunMessage;
+
+enum ProtocolType {
+  PROTO_UDP,
+  PROTO_TCP,
+  PROTO_SSLTCP,
+  PROTO_LAST = PROTO_SSLTCP
+};
+
+// Defines the interface for a port, which represents a local communication
+// mechanism that can be used to create connections to similar mechanisms of
+// the other client. Various types of ports will implement this interface.
+class PortInterface {
+ public:
+  virtual ~PortInterface() {}
+
+  virtual const std::string& Type() const = 0;
+  virtual rtc::Network* Network() const = 0;
+
+  virtual void SetIceProtocolType(IceProtocolType protocol) = 0;
+  virtual IceProtocolType IceProtocol() const = 0;
+
+  // Methods to set/get ICE role and tiebreaker values.
+  virtual void SetIceRole(IceRole role) = 0;
+  virtual IceRole GetIceRole() const = 0;
+
+  virtual void SetIceTiebreaker(uint64 tiebreaker) = 0;
+  virtual uint64 IceTiebreaker() const = 0;
+
+  virtual bool SharedSocket() const = 0;
+
+  // PrepareAddress will attempt to get an address for this port that other
+  // clients can send to.  It may take some time before the address is ready.
+  // Once it is ready, we will send SignalAddressReady.  If errors are
+  // preventing the port from getting an address, it may send
+  // SignalAddressError.
+  virtual void PrepareAddress() = 0;
+
+  // Returns the connection to the given address or NULL if none exists.
+  virtual Connection* GetConnection(
+      const rtc::SocketAddress& remote_addr) = 0;
+
+  // Creates a new connection to the given address.
+  enum CandidateOrigin { ORIGIN_THIS_PORT, ORIGIN_OTHER_PORT, ORIGIN_MESSAGE };
+  virtual Connection* CreateConnection(
+      const Candidate& remote_candidate, CandidateOrigin origin) = 0;
+
+  // Functions on the underlying socket(s).
+  virtual int SetOption(rtc::Socket::Option opt, int value) = 0;
+  virtual int GetOption(rtc::Socket::Option opt, int* value) = 0;
+  virtual int GetError() = 0;
+
+  virtual const std::vector<Candidate>& Candidates() const = 0;
+
+  // Sends the given packet to the given address, provided that the address is
+  // that of a connection or an address that has sent to us already.
+  virtual int SendTo(const void* data, size_t size,
+                     const rtc::SocketAddress& addr,
+                     const rtc::PacketOptions& options, bool payload) = 0;
+
+  // Indicates that we received a successful STUN binding request from an
+  // address that doesn't correspond to any current connection.  To turn this
+  // into a real connection, call CreateConnection.
+  sigslot::signal6<PortInterface*, const rtc::SocketAddress&,
+                   ProtocolType, IceMessage*, const std::string&,
+                   bool> SignalUnknownAddress;
+
+  // Sends a response message (normal or error) to the given request.  One of
+  // these methods should be called as a response to SignalUnknownAddress.
+  // NOTE: You MUST call CreateConnection BEFORE SendBindingResponse.
+  virtual void SendBindingResponse(StunMessage* request,
+                                   const rtc::SocketAddress& addr) = 0;
+  virtual void SendBindingErrorResponse(
+      StunMessage* request, const rtc::SocketAddress& addr,
+      int error_code, const std::string& reason) = 0;
+
+  // Signaled when this port decides to delete itself because it no longer has
+  // any usefulness.
+  sigslot::signal1<PortInterface*> SignalDestroyed;
+
+  // Signaled when Port discovers ice role conflict with the peer.
+  sigslot::signal1<PortInterface*> SignalRoleConflict;
+
+  // Normally, packets arrive through a connection (or they result signaling of
+  // unknown address).  Calling this method turns off delivery of packets
+  // through their respective connection and instead delivers every packet
+  // through this port.
+  virtual void EnablePortPackets() = 0;
+  sigslot::signal4<PortInterface*, const char*, size_t,
+                   const rtc::SocketAddress&> SignalReadPacket;
+
+  virtual std::string ToString() const = 0;
+
+ protected:
+  PortInterface() {}
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_PORTINTERFACE_H_
diff --git a/webrtc/p2p/base/portproxy.cc b/webrtc/p2p/base/portproxy.cc
new file mode 100644
index 0000000..e28af27
--- /dev/null
+++ b/webrtc/p2p/base/portproxy.cc
@@ -0,0 +1,163 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/portproxy.h"
+
+namespace cricket {
+
+void PortProxy::set_impl(PortInterface* port) {
+  impl_ = port;
+  impl_->SignalUnknownAddress.connect(
+      this, &PortProxy::OnUnknownAddress);
+  impl_->SignalDestroyed.connect(this, &PortProxy::OnPortDestroyed);
+  impl_->SignalRoleConflict.connect(this, &PortProxy::OnRoleConflict);
+}
+
+const std::string& PortProxy::Type() const {
+  ASSERT(impl_ != NULL);
+  return impl_->Type();
+}
+
+rtc::Network* PortProxy::Network() const {
+  ASSERT(impl_ != NULL);
+  return impl_->Network();
+}
+
+void PortProxy::SetIceProtocolType(IceProtocolType protocol) {
+  ASSERT(impl_ != NULL);
+  impl_->SetIceProtocolType(protocol);
+}
+
+IceProtocolType PortProxy::IceProtocol() const {
+  ASSERT(impl_ != NULL);
+  return impl_->IceProtocol();
+}
+
+// Methods to set/get ICE role and tiebreaker values.
+void PortProxy::SetIceRole(IceRole role) {
+  ASSERT(impl_ != NULL);
+  impl_->SetIceRole(role);
+}
+
+IceRole PortProxy::GetIceRole() const {
+  ASSERT(impl_ != NULL);
+  return impl_->GetIceRole();
+}
+
+void PortProxy::SetIceTiebreaker(uint64 tiebreaker) {
+  ASSERT(impl_ != NULL);
+  impl_->SetIceTiebreaker(tiebreaker);
+}
+
+uint64 PortProxy::IceTiebreaker() const {
+  ASSERT(impl_ != NULL);
+  return impl_->IceTiebreaker();
+}
+
+bool PortProxy::SharedSocket() const {
+  ASSERT(impl_ != NULL);
+  return impl_->SharedSocket();
+}
+
+void PortProxy::PrepareAddress() {
+  ASSERT(impl_ != NULL);
+  impl_->PrepareAddress();
+}
+
+Connection* PortProxy::CreateConnection(const Candidate& remote_candidate,
+                                        CandidateOrigin origin) {
+  ASSERT(impl_ != NULL);
+  return impl_->CreateConnection(remote_candidate, origin);
+}
+
+int PortProxy::SendTo(const void* data,
+                      size_t size,
+                      const rtc::SocketAddress& addr,
+                      const rtc::PacketOptions& options,
+                      bool payload) {
+  ASSERT(impl_ != NULL);
+  return impl_->SendTo(data, size, addr, options, payload);
+}
+
+int PortProxy::SetOption(rtc::Socket::Option opt,
+                         int value) {
+  ASSERT(impl_ != NULL);
+  return impl_->SetOption(opt, value);
+}
+
+int PortProxy::GetOption(rtc::Socket::Option opt,
+                         int* value) {
+  ASSERT(impl_ != NULL);
+  return impl_->GetOption(opt, value);
+}
+
+int PortProxy::GetError() {
+  ASSERT(impl_ != NULL);
+  return impl_->GetError();
+}
+
+const std::vector<Candidate>& PortProxy::Candidates() const {
+  ASSERT(impl_ != NULL);
+  return impl_->Candidates();
+}
+
+void PortProxy::SendBindingResponse(
+    StunMessage* request, const rtc::SocketAddress& addr) {
+  ASSERT(impl_ != NULL);
+  impl_->SendBindingResponse(request, addr);
+}
+
+Connection* PortProxy::GetConnection(
+    const rtc::SocketAddress& remote_addr) {
+  ASSERT(impl_ != NULL);
+  return impl_->GetConnection(remote_addr);
+}
+
+void PortProxy::SendBindingErrorResponse(
+    StunMessage* request, const rtc::SocketAddress& addr,
+    int error_code, const std::string& reason) {
+  ASSERT(impl_ != NULL);
+  impl_->SendBindingErrorResponse(request, addr, error_code, reason);
+}
+
+void PortProxy::EnablePortPackets() {
+  ASSERT(impl_ != NULL);
+  impl_->EnablePortPackets();
+}
+
+std::string PortProxy::ToString() const {
+  ASSERT(impl_ != NULL);
+  return impl_->ToString();
+}
+
+void PortProxy::OnUnknownAddress(
+    PortInterface *port,
+    const rtc::SocketAddress &addr,
+    ProtocolType proto,
+    IceMessage *stun_msg,
+    const std::string &remote_username,
+    bool port_muxed) {
+  ASSERT(port == impl_);
+  ASSERT(!port_muxed);
+  SignalUnknownAddress(this, addr, proto, stun_msg, remote_username, true);
+}
+
+void PortProxy::OnRoleConflict(PortInterface* port) {
+  ASSERT(port == impl_);
+  SignalRoleConflict(this);
+}
+
+void PortProxy::OnPortDestroyed(PortInterface* port) {
+  ASSERT(port == impl_);
+  // |port| will be destroyed in PortAllocatorSessionMuxer.
+  SignalDestroyed(this);
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/portproxy.h b/webrtc/p2p/base/portproxy.h
new file mode 100644
index 0000000..79507fe
--- /dev/null
+++ b/webrtc/p2p/base/portproxy.h
@@ -0,0 +1,87 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_PORTPROXY_H_
+#define WEBRTC_P2P_BASE_PORTPROXY_H_
+
+#include "webrtc/p2p/base/portinterface.h"
+#include "webrtc/base/sigslot.h"
+
+namespace rtc {
+class Network;
+}
+
+namespace cricket {
+
+class PortProxy : public PortInterface, public sigslot::has_slots<> {
+ public:
+  PortProxy() {}
+  virtual ~PortProxy() {}
+
+  PortInterface* impl() { return impl_; }
+  void set_impl(PortInterface* port);
+
+  virtual const std::string& Type() const;
+  virtual rtc::Network* Network() const;
+
+  virtual void SetIceProtocolType(IceProtocolType protocol);
+  virtual IceProtocolType IceProtocol() const;
+
+  // Methods to set/get ICE role and tiebreaker values.
+  virtual void SetIceRole(IceRole role);
+  virtual IceRole GetIceRole() const;
+
+  virtual void SetIceTiebreaker(uint64 tiebreaker);
+  virtual uint64 IceTiebreaker() const;
+
+  virtual bool SharedSocket() const;
+
+  // Forwards call to the actual Port.
+  virtual void PrepareAddress();
+  virtual Connection* CreateConnection(const Candidate& remote_candidate,
+                                       CandidateOrigin origin);
+  virtual Connection* GetConnection(
+      const rtc::SocketAddress& remote_addr);
+
+  virtual int SendTo(const void* data, size_t size,
+                     const rtc::SocketAddress& addr,
+                     const rtc::PacketOptions& options,
+                     bool payload);
+  virtual int SetOption(rtc::Socket::Option opt, int value);
+  virtual int GetOption(rtc::Socket::Option opt, int* value);
+  virtual int GetError();
+
+  virtual const std::vector<Candidate>& Candidates() const;
+
+  virtual void SendBindingResponse(StunMessage* request,
+                                   const rtc::SocketAddress& addr);
+  virtual void SendBindingErrorResponse(
+        StunMessage* request, const rtc::SocketAddress& addr,
+        int error_code, const std::string& reason);
+
+  virtual void EnablePortPackets();
+  virtual std::string ToString() const;
+
+ private:
+  void OnUnknownAddress(PortInterface *port,
+                        const rtc::SocketAddress &addr,
+                        ProtocolType proto,
+                        IceMessage *stun_msg,
+                        const std::string &remote_username,
+                        bool port_muxed);
+  void OnRoleConflict(PortInterface* port);
+  void OnPortDestroyed(PortInterface* port);
+
+  PortInterface* impl_;
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_PORTPROXY_H_
diff --git a/webrtc/p2p/base/pseudotcp.cc b/webrtc/p2p/base/pseudotcp.cc
new file mode 100644
index 0000000..0dfe7d8
--- /dev/null
+++ b/webrtc/p2p/base/pseudotcp.cc
@@ -0,0 +1,1274 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/pseudotcp.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <set>
+
+#include "webrtc/base/basictypes.h"
+#include "webrtc/base/bytebuffer.h"
+#include "webrtc/base/byteorder.h"
+#include "webrtc/base/common.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/socket.h"
+#include "webrtc/base/stringutils.h"
+#include "webrtc/base/timeutils.h"
+
+// The following logging is for detailed (packet-level) analysis only.
+#define _DBG_NONE     0
+#define _DBG_NORMAL   1
+#define _DBG_VERBOSE  2
+#define _DEBUGMSG _DBG_NONE
+
+namespace cricket {
+
+//////////////////////////////////////////////////////////////////////
+// Network Constants
+//////////////////////////////////////////////////////////////////////
+
+// Standard MTUs
+const uint16 PACKET_MAXIMUMS[] = {
+  65535,    // Theoretical maximum, Hyperchannel
+  32000,    // Nothing
+  17914,    // 16Mb IBM Token Ring
+  8166,   // IEEE 802.4
+  //4464,   // IEEE 802.5 (4Mb max)
+  4352,   // FDDI
+  //2048,   // Wideband Network
+  2002,   // IEEE 802.5 (4Mb recommended)
+  //1536,   // Expermental Ethernet Networks
+  //1500,   // Ethernet, Point-to-Point (default)
+  1492,   // IEEE 802.3
+  1006,   // SLIP, ARPANET
+  //576,    // X.25 Networks
+  //544,    // DEC IP Portal
+  //512,    // NETBIOS
+  508,    // IEEE 802/Source-Rt Bridge, ARCNET
+  296,    // Point-to-Point (low delay)
+  //68,     // Official minimum
+  0,      // End of list marker
+};
+
+const uint32 MAX_PACKET = 65535;
+// Note: we removed lowest level because packet overhead was larger!
+const uint32 MIN_PACKET = 296;
+
+const uint32 IP_HEADER_SIZE = 20; // (+ up to 40 bytes of options?)
+const uint32 UDP_HEADER_SIZE = 8;
+// TODO: Make JINGLE_HEADER_SIZE transparent to this code?
+const uint32 JINGLE_HEADER_SIZE = 64; // when relay framing is in use
+
+// Default size for receive and send buffer.
+const uint32 DEFAULT_RCV_BUF_SIZE = 60 * 1024;
+const uint32 DEFAULT_SND_BUF_SIZE = 90 * 1024;
+
+//////////////////////////////////////////////////////////////////////
+// Global Constants and Functions
+//////////////////////////////////////////////////////////////////////
+//
+//    0                   1                   2                   3
+//    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+//    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//  0 |                      Conversation Number                      |
+//    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//  4 |                        Sequence Number                        |
+//    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//  8 |                     Acknowledgment Number                     |
+//    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//    |               |   |U|A|P|R|S|F|                               |
+// 12 |    Control    |   |R|C|S|S|Y|I|            Window             |
+//    |               |   |G|K|H|T|N|N|                               |
+//    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// 16 |                       Timestamp sending                       |
+//    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// 20 |                      Timestamp receiving                      |
+//    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// 24 |                             data                              |
+//    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//
+//////////////////////////////////////////////////////////////////////
+
+#define PSEUDO_KEEPALIVE 0
+
+const uint32 HEADER_SIZE = 24;
+const uint32 PACKET_OVERHEAD = HEADER_SIZE + UDP_HEADER_SIZE + IP_HEADER_SIZE + JINGLE_HEADER_SIZE;
+
+const uint32 MIN_RTO   =   250; // 250 ms (RFC1122, Sec 4.2.3.1 "fractions of a second")
+const uint32 DEF_RTO   =  3000; // 3 seconds (RFC1122, Sec 4.2.3.1)
+const uint32 MAX_RTO   = 60000; // 60 seconds
+const uint32 DEF_ACK_DELAY = 100; // 100 milliseconds
+
+const uint8 FLAG_CTL = 0x02;
+const uint8 FLAG_RST = 0x04;
+
+const uint8 CTL_CONNECT = 0;
+
+// TCP options.
+const uint8 TCP_OPT_EOL = 0;  // End of list.
+const uint8 TCP_OPT_NOOP = 1;  // No-op.
+const uint8 TCP_OPT_MSS = 2;  // Maximum segment size.
+const uint8 TCP_OPT_WND_SCALE = 3;  // Window scale factor.
+
+const long DEFAULT_TIMEOUT = 4000; // If there are no pending clocks, wake up every 4 seconds
+const long CLOSED_TIMEOUT = 60 * 1000; // If the connection is closed, once per minute
+
+#if PSEUDO_KEEPALIVE
+// !?! Rethink these times
+const uint32 IDLE_PING = 20 * 1000; // 20 seconds (note: WinXP SP2 firewall udp timeout is 90 seconds)
+const uint32 IDLE_TIMEOUT = 90 * 1000; // 90 seconds;
+#endif // PSEUDO_KEEPALIVE
+
+//////////////////////////////////////////////////////////////////////
+// Helper Functions
+//////////////////////////////////////////////////////////////////////
+
+inline void long_to_bytes(uint32 val, void* buf) {
+  *static_cast<uint32*>(buf) = rtc::HostToNetwork32(val);
+}
+
+inline void short_to_bytes(uint16 val, void* buf) {
+  *static_cast<uint16*>(buf) = rtc::HostToNetwork16(val);
+}
+
+inline uint32 bytes_to_long(const void* buf) {
+  return rtc::NetworkToHost32(*static_cast<const uint32*>(buf));
+}
+
+inline uint16 bytes_to_short(const void* buf) {
+  return rtc::NetworkToHost16(*static_cast<const uint16*>(buf));
+}
+
+uint32 bound(uint32 lower, uint32 middle, uint32 upper) {
+  return rtc::_min(rtc::_max(lower, middle), upper);
+}
+
+//////////////////////////////////////////////////////////////////////
+// Debugging Statistics
+//////////////////////////////////////////////////////////////////////
+
+#if 0  // Not used yet
+
+enum Stat {
+  S_SENT_PACKET,   // All packet sends
+  S_RESENT_PACKET, // All packet sends that are retransmits
+  S_RECV_PACKET,   // All packet receives
+  S_RECV_NEW,      // All packet receives that are too new
+  S_RECV_OLD,      // All packet receives that are too old
+  S_NUM_STATS
+};
+
+const char* const STAT_NAMES[S_NUM_STATS] = {
+  "snt",
+  "snt-r",
+  "rcv"
+  "rcv-n",
+  "rcv-o"
+};
+
+int g_stats[S_NUM_STATS];
+inline void Incr(Stat s) { ++g_stats[s]; }
+void ReportStats() {
+  char buffer[256];
+  size_t len = 0;
+  for (int i = 0; i < S_NUM_STATS; ++i) {
+    len += rtc::sprintfn(buffer, ARRAY_SIZE(buffer), "%s%s:%d",
+                               (i == 0) ? "" : ",", STAT_NAMES[i], g_stats[i]);
+    g_stats[i] = 0;
+  }
+  LOG(LS_INFO) << "Stats[" << buffer << "]";
+}
+
+#endif
+
+//////////////////////////////////////////////////////////////////////
+// PseudoTcp
+//////////////////////////////////////////////////////////////////////
+
+uint32 PseudoTcp::Now() {
+#if 0  // Use this to synchronize timers with logging timestamps (easier debug)
+  return rtc::TimeSince(StartTime());
+#else
+  return rtc::Time();
+#endif
+}
+
+PseudoTcp::PseudoTcp(IPseudoTcpNotify* notify, uint32 conv)
+    : m_notify(notify),
+      m_shutdown(SD_NONE),
+      m_error(0),
+      m_rbuf_len(DEFAULT_RCV_BUF_SIZE),
+      m_rbuf(m_rbuf_len),
+      m_sbuf_len(DEFAULT_SND_BUF_SIZE),
+      m_sbuf(m_sbuf_len) {
+
+  // Sanity check on buffer sizes (needed for OnTcpWriteable notification logic)
+  ASSERT(m_rbuf_len + MIN_PACKET < m_sbuf_len);
+
+  uint32 now = Now();
+
+  m_state = TCP_LISTEN;
+  m_conv = conv;
+  m_rcv_wnd = m_rbuf_len;
+  m_rwnd_scale = m_swnd_scale = 0;
+  m_snd_nxt = 0;
+  m_snd_wnd = 1;
+  m_snd_una = m_rcv_nxt = 0;
+  m_bReadEnable = true;
+  m_bWriteEnable = false;
+  m_t_ack = 0;
+
+  m_msslevel = 0;
+  m_largest = 0;
+  ASSERT(MIN_PACKET > PACKET_OVERHEAD);
+  m_mss = MIN_PACKET - PACKET_OVERHEAD;
+  m_mtu_advise = MAX_PACKET;
+
+  m_rto_base = 0;
+
+  m_cwnd = 2 * m_mss;
+  m_ssthresh = m_rbuf_len;
+  m_lastrecv = m_lastsend = m_lasttraffic = now;
+  m_bOutgoing = false;
+
+  m_dup_acks = 0;
+  m_recover = 0;
+
+  m_ts_recent = m_ts_lastack = 0;
+
+  m_rx_rto = DEF_RTO;
+  m_rx_srtt = m_rx_rttvar = 0;
+
+  m_use_nagling = true;
+  m_ack_delay = DEF_ACK_DELAY;
+  m_support_wnd_scale = true;
+}
+
+PseudoTcp::~PseudoTcp() {
+}
+
+int PseudoTcp::Connect() {
+  if (m_state != TCP_LISTEN) {
+    m_error = EINVAL;
+    return -1;
+  }
+
+  m_state = TCP_SYN_SENT;
+  LOG(LS_INFO) << "State: TCP_SYN_SENT";
+
+  queueConnectMessage();
+  attemptSend();
+
+  return 0;
+}
+
+void PseudoTcp::NotifyMTU(uint16 mtu) {
+  m_mtu_advise = mtu;
+  if (m_state == TCP_ESTABLISHED) {
+    adjustMTU();
+  }
+}
+
+void PseudoTcp::NotifyClock(uint32 now) {
+  if (m_state == TCP_CLOSED)
+    return;
+
+    // Check if it's time to retransmit a segment
+  if (m_rto_base && (rtc::TimeDiff(m_rto_base + m_rx_rto, now) <= 0)) {
+    if (m_slist.empty()) {
+      ASSERT(false);
+    } else {
+      // Note: (m_slist.front().xmit == 0)) {
+      // retransmit segments
+#if _DEBUGMSG >= _DBG_NORMAL
+      LOG(LS_INFO) << "timeout retransmit (rto: " << m_rx_rto
+                   << ") (rto_base: " << m_rto_base
+                   << ") (now: " << now
+                   << ") (dup_acks: " << static_cast<unsigned>(m_dup_acks)
+                   << ")";
+#endif // _DEBUGMSG
+      if (!transmit(m_slist.begin(), now)) {
+        closedown(ECONNABORTED);
+        return;
+      }
+
+      uint32 nInFlight = m_snd_nxt - m_snd_una;
+      m_ssthresh = rtc::_max(nInFlight / 2, 2 * m_mss);
+      //LOG(LS_INFO) << "m_ssthresh: " << m_ssthresh << "  nInFlight: " << nInFlight << "  m_mss: " << m_mss;
+      m_cwnd = m_mss;
+
+      // Back off retransmit timer.  Note: the limit is lower when connecting.
+      uint32 rto_limit = (m_state < TCP_ESTABLISHED) ? DEF_RTO : MAX_RTO;
+      m_rx_rto = rtc::_min(rto_limit, m_rx_rto * 2);
+      m_rto_base = now;
+    }
+  }
+
+  // Check if it's time to probe closed windows
+  if ((m_snd_wnd == 0)
+        && (rtc::TimeDiff(m_lastsend + m_rx_rto, now) <= 0)) {
+    if (rtc::TimeDiff(now, m_lastrecv) >= 15000) {
+      closedown(ECONNABORTED);
+      return;
+    }
+
+    // probe the window
+    packet(m_snd_nxt - 1, 0, 0, 0);
+    m_lastsend = now;
+
+    // back off retransmit timer
+    m_rx_rto = rtc::_min(MAX_RTO, m_rx_rto * 2);
+  }
+
+  // Check if it's time to send delayed acks
+  if (m_t_ack && (rtc::TimeDiff(m_t_ack + m_ack_delay, now) <= 0)) {
+    packet(m_snd_nxt, 0, 0, 0);
+  }
+
+#if PSEUDO_KEEPALIVE
+  // Check for idle timeout
+  if ((m_state == TCP_ESTABLISHED) && (TimeDiff(m_lastrecv + IDLE_TIMEOUT, now) <= 0)) {
+    closedown(ECONNABORTED);
+    return;
+  }
+
+  // Check for ping timeout (to keep udp mapping open)
+  if ((m_state == TCP_ESTABLISHED) && (TimeDiff(m_lasttraffic + (m_bOutgoing ? IDLE_PING * 3/2 : IDLE_PING), now) <= 0)) {
+    packet(m_snd_nxt, 0, 0, 0);
+  }
+#endif // PSEUDO_KEEPALIVE
+}
+
+bool PseudoTcp::NotifyPacket(const char* buffer, size_t len) {
+  if (len > MAX_PACKET) {
+    LOG_F(WARNING) << "packet too large";
+    return false;
+  }
+  return parse(reinterpret_cast<const uint8 *>(buffer), uint32(len));
+}
+
+bool PseudoTcp::GetNextClock(uint32 now, long& timeout) {
+  return clock_check(now, timeout);
+}
+
+void PseudoTcp::GetOption(Option opt, int* value) {
+  if (opt == OPT_NODELAY) {
+    *value = m_use_nagling ? 0 : 1;
+  } else if (opt == OPT_ACKDELAY) {
+    *value = m_ack_delay;
+  } else if (opt == OPT_SNDBUF) {
+    *value = m_sbuf_len;
+  } else if (opt == OPT_RCVBUF) {
+    *value = m_rbuf_len;
+  } else {
+    ASSERT(false);
+  }
+}
+void PseudoTcp::SetOption(Option opt, int value) {
+  if (opt == OPT_NODELAY) {
+    m_use_nagling = value == 0;
+  } else if (opt == OPT_ACKDELAY) {
+    m_ack_delay = value;
+  } else if (opt == OPT_SNDBUF) {
+    ASSERT(m_state == TCP_LISTEN);
+    resizeSendBuffer(value);
+  } else if (opt == OPT_RCVBUF) {
+    ASSERT(m_state == TCP_LISTEN);
+    resizeReceiveBuffer(value);
+  } else {
+    ASSERT(false);
+  }
+}
+
+uint32 PseudoTcp::GetCongestionWindow() const {
+  return m_cwnd;
+}
+
+uint32 PseudoTcp::GetBytesInFlight() const {
+  return m_snd_nxt - m_snd_una;
+}
+
+uint32 PseudoTcp::GetBytesBufferedNotSent() const {
+  size_t buffered_bytes = 0;
+  m_sbuf.GetBuffered(&buffered_bytes);
+  return static_cast<uint32>(m_snd_una + buffered_bytes - m_snd_nxt);
+}
+
+uint32 PseudoTcp::GetRoundTripTimeEstimateMs() const {
+  return m_rx_srtt;
+}
+
+//
+// IPStream Implementation
+//
+
+int PseudoTcp::Recv(char* buffer, size_t len) {
+  if (m_state != TCP_ESTABLISHED) {
+    m_error = ENOTCONN;
+    return SOCKET_ERROR;
+  }
+
+  size_t read = 0;
+  rtc::StreamResult result = m_rbuf.Read(buffer, len, &read, NULL);
+
+  // If there's no data in |m_rbuf|.
+  if (result == rtc::SR_BLOCK) {
+    m_bReadEnable = true;
+    m_error = EWOULDBLOCK;
+    return SOCKET_ERROR;
+  }
+  ASSERT(result == rtc::SR_SUCCESS);
+
+  size_t available_space = 0;
+  m_rbuf.GetWriteRemaining(&available_space);
+
+  if (uint32(available_space) - m_rcv_wnd >=
+      rtc::_min<uint32>(m_rbuf_len / 2, m_mss)) {
+    // TODO(jbeda): !?! Not sure about this was closed business
+    bool bWasClosed = (m_rcv_wnd == 0);
+    m_rcv_wnd = static_cast<uint32>(available_space);
+
+    if (bWasClosed) {
+      attemptSend(sfImmediateAck);
+    }
+  }
+
+  return static_cast<int>(read);
+}
+
+int PseudoTcp::Send(const char* buffer, size_t len) {
+  if (m_state != TCP_ESTABLISHED) {
+    m_error = ENOTCONN;
+    return SOCKET_ERROR;
+  }
+
+  size_t available_space = 0;
+  m_sbuf.GetWriteRemaining(&available_space);
+
+  if (!available_space) {
+    m_bWriteEnable = true;
+    m_error = EWOULDBLOCK;
+    return SOCKET_ERROR;
+  }
+
+  int written = queue(buffer, uint32(len), false);
+  attemptSend();
+  return written;
+}
+
+void PseudoTcp::Close(bool force) {
+  LOG_F(LS_VERBOSE) << "(" << (force ? "true" : "false") << ")";
+  m_shutdown = force ? SD_FORCEFUL : SD_GRACEFUL;
+}
+
+int PseudoTcp::GetError() {
+  return m_error;
+}
+
+//
+// Internal Implementation
+//
+
+uint32 PseudoTcp::queue(const char* data, uint32 len, bool bCtrl) {
+  size_t available_space = 0;
+  m_sbuf.GetWriteRemaining(&available_space);
+
+  if (len > static_cast<uint32>(available_space)) {
+    ASSERT(!bCtrl);
+    len = static_cast<uint32>(available_space);
+  }
+
+  // We can concatenate data if the last segment is the same type
+  // (control v. regular data), and has not been transmitted yet
+  if (!m_slist.empty() && (m_slist.back().bCtrl == bCtrl) &&
+      (m_slist.back().xmit == 0)) {
+    m_slist.back().len += len;
+  } else {
+    size_t snd_buffered = 0;
+    m_sbuf.GetBuffered(&snd_buffered);
+    SSegment sseg(static_cast<uint32>(m_snd_una + snd_buffered), len, bCtrl);
+    m_slist.push_back(sseg);
+  }
+
+  size_t written = 0;
+  m_sbuf.Write(data, len, &written, NULL);
+  return static_cast<uint32>(written);
+}
+
+IPseudoTcpNotify::WriteResult PseudoTcp::packet(uint32 seq, uint8 flags,
+                                                uint32 offset, uint32 len) {
+  ASSERT(HEADER_SIZE + len <= MAX_PACKET);
+
+  uint32 now = Now();
+
+  rtc::scoped_ptr<uint8[]> buffer(new uint8[MAX_PACKET]);
+  long_to_bytes(m_conv, buffer.get());
+  long_to_bytes(seq, buffer.get() + 4);
+  long_to_bytes(m_rcv_nxt, buffer.get() + 8);
+  buffer[12] = 0;
+  buffer[13] = flags;
+  short_to_bytes(
+      static_cast<uint16>(m_rcv_wnd >> m_rwnd_scale), buffer.get() + 14);
+
+  // Timestamp computations
+  long_to_bytes(now, buffer.get() + 16);
+  long_to_bytes(m_ts_recent, buffer.get() + 20);
+  m_ts_lastack = m_rcv_nxt;
+
+  if (len) {
+    size_t bytes_read = 0;
+    rtc::StreamResult result = m_sbuf.ReadOffset(
+        buffer.get() + HEADER_SIZE, len, offset, &bytes_read);
+    RTC_UNUSED(result);
+    ASSERT(result == rtc::SR_SUCCESS);
+    ASSERT(static_cast<uint32>(bytes_read) == len);
+  }
+
+#if _DEBUGMSG >= _DBG_VERBOSE
+  LOG(LS_INFO) << "<-- <CONV=" << m_conv
+               << "><FLG=" << static_cast<unsigned>(flags)
+               << "><SEQ=" << seq << ":" << seq + len
+               << "><ACK=" << m_rcv_nxt
+               << "><WND=" << m_rcv_wnd
+               << "><TS="  << (now % 10000)
+               << "><TSR=" << (m_ts_recent % 10000)
+               << "><LEN=" << len << ">";
+#endif // _DEBUGMSG
+
+  IPseudoTcpNotify::WriteResult wres = m_notify->TcpWritePacket(
+      this, reinterpret_cast<char *>(buffer.get()), len + HEADER_SIZE);
+  // Note: When len is 0, this is an ACK packet.  We don't read the return value for those,
+  // and thus we won't retry.  So go ahead and treat the packet as a success (basically simulate
+  // as if it were dropped), which will prevent our timers from being messed up.
+  if ((wres != IPseudoTcpNotify::WR_SUCCESS) && (0 != len))
+    return wres;
+
+  m_t_ack = 0;
+  if (len > 0) {
+    m_lastsend = now;
+  }
+  m_lasttraffic = now;
+  m_bOutgoing = true;
+
+  return IPseudoTcpNotify::WR_SUCCESS;
+}
+
+bool PseudoTcp::parse(const uint8* buffer, uint32 size) {
+  if (size < 12)
+    return false;
+
+  Segment seg;
+  seg.conv = bytes_to_long(buffer);
+  seg.seq = bytes_to_long(buffer + 4);
+  seg.ack = bytes_to_long(buffer + 8);
+  seg.flags = buffer[13];
+  seg.wnd = bytes_to_short(buffer + 14);
+
+  seg.tsval = bytes_to_long(buffer + 16);
+  seg.tsecr = bytes_to_long(buffer + 20);
+
+  seg.data = reinterpret_cast<const char *>(buffer) + HEADER_SIZE;
+  seg.len = size - HEADER_SIZE;
+
+#if _DEBUGMSG >= _DBG_VERBOSE
+  LOG(LS_INFO) << "--> <CONV=" << seg.conv
+               << "><FLG=" << static_cast<unsigned>(seg.flags)
+               << "><SEQ=" << seg.seq << ":" << seg.seq + seg.len
+               << "><ACK=" << seg.ack
+               << "><WND=" << seg.wnd
+               << "><TS="  << (seg.tsval % 10000)
+               << "><TSR=" << (seg.tsecr % 10000)
+               << "><LEN=" << seg.len << ">";
+#endif // _DEBUGMSG
+
+  return process(seg);
+}
+
+bool PseudoTcp::clock_check(uint32 now, long& nTimeout) {
+  if (m_shutdown == SD_FORCEFUL)
+    return false;
+
+  size_t snd_buffered = 0;
+  m_sbuf.GetBuffered(&snd_buffered);
+  if ((m_shutdown == SD_GRACEFUL)
+      && ((m_state != TCP_ESTABLISHED)
+          || ((snd_buffered == 0) && (m_t_ack == 0)))) {
+    return false;
+  }
+
+  if (m_state == TCP_CLOSED) {
+    nTimeout = CLOSED_TIMEOUT;
+    return true;
+  }
+
+  nTimeout = DEFAULT_TIMEOUT;
+
+  if (m_t_ack) {
+    nTimeout = rtc::_min<int32>(nTimeout,
+      rtc::TimeDiff(m_t_ack + m_ack_delay, now));
+  }
+  if (m_rto_base) {
+    nTimeout = rtc::_min<int32>(nTimeout,
+      rtc::TimeDiff(m_rto_base + m_rx_rto, now));
+  }
+  if (m_snd_wnd == 0) {
+    nTimeout = rtc::_min<int32>(nTimeout, rtc::TimeDiff(m_lastsend + m_rx_rto, now));
+  }
+#if PSEUDO_KEEPALIVE
+  if (m_state == TCP_ESTABLISHED) {
+    nTimeout = rtc::_min<int32>(nTimeout,
+      rtc::TimeDiff(m_lasttraffic + (m_bOutgoing ? IDLE_PING * 3/2 : IDLE_PING), now));
+  }
+#endif // PSEUDO_KEEPALIVE
+  return true;
+}
+
+bool PseudoTcp::process(Segment& seg) {
+  // If this is the wrong conversation, send a reset!?! (with the correct conversation?)
+  if (seg.conv != m_conv) {
+    //if ((seg.flags & FLAG_RST) == 0) {
+    //  packet(tcb, seg.ack, 0, FLAG_RST, 0, 0);
+    //}
+    LOG_F(LS_ERROR) << "wrong conversation";
+    return false;
+  }
+
+  uint32 now = Now();
+  m_lasttraffic = m_lastrecv = now;
+  m_bOutgoing = false;
+
+  if (m_state == TCP_CLOSED) {
+    // !?! send reset?
+    LOG_F(LS_ERROR) << "closed";
+    return false;
+  }
+
+  // Check if this is a reset segment
+  if (seg.flags & FLAG_RST) {
+    closedown(ECONNRESET);
+    return false;
+  }
+
+  // Check for control data
+  bool bConnect = false;
+  if (seg.flags & FLAG_CTL) {
+    if (seg.len == 0) {
+      LOG_F(LS_ERROR) << "Missing control code";
+      return false;
+    } else if (seg.data[0] == CTL_CONNECT) {
+      bConnect = true;
+
+      // TCP options are in the remainder of the payload after CTL_CONNECT.
+      parseOptions(&seg.data[1], seg.len - 1);
+
+      if (m_state == TCP_LISTEN) {
+        m_state = TCP_SYN_RECEIVED;
+        LOG(LS_INFO) << "State: TCP_SYN_RECEIVED";
+        //m_notify->associate(addr);
+        queueConnectMessage();
+      } else if (m_state == TCP_SYN_SENT) {
+        m_state = TCP_ESTABLISHED;
+        LOG(LS_INFO) << "State: TCP_ESTABLISHED";
+        adjustMTU();
+        if (m_notify) {
+          m_notify->OnTcpOpen(this);
+        }
+        //notify(evOpen);
+      }
+    } else {
+      LOG_F(LS_WARNING) << "Unknown control code: " << seg.data[0];
+      return false;
+    }
+  }
+
+  // Update timestamp
+  if ((seg.seq <= m_ts_lastack) && (m_ts_lastack < seg.seq + seg.len)) {
+    m_ts_recent = seg.tsval;
+  }
+
+  // Check if this is a valuable ack
+  if ((seg.ack > m_snd_una) && (seg.ack <= m_snd_nxt)) {
+    // Calculate round-trip time
+    if (seg.tsecr) {
+      int32 rtt = rtc::TimeDiff(now, seg.tsecr);
+      if (rtt >= 0) {
+        if (m_rx_srtt == 0) {
+          m_rx_srtt = rtt;
+          m_rx_rttvar = rtt / 2;
+        } else {
+          uint32 unsigned_rtt = static_cast<uint32>(rtt);
+          uint32 abs_err = unsigned_rtt > m_rx_srtt ? unsigned_rtt - m_rx_srtt
+                                                    : m_rx_srtt - unsigned_rtt;
+          m_rx_rttvar = (3 * m_rx_rttvar + abs_err) / 4;
+          m_rx_srtt = (7 * m_rx_srtt + rtt) / 8;
+        }
+        m_rx_rto = bound(MIN_RTO, m_rx_srtt +
+            rtc::_max<uint32>(1, 4 * m_rx_rttvar), MAX_RTO);
+#if _DEBUGMSG >= _DBG_VERBOSE
+        LOG(LS_INFO) << "rtt: " << rtt
+                     << "  srtt: " << m_rx_srtt
+                     << "  rto: " << m_rx_rto;
+#endif // _DEBUGMSG
+      } else {
+        ASSERT(false);
+      }
+    }
+
+    m_snd_wnd = static_cast<uint32>(seg.wnd) << m_swnd_scale;
+
+    uint32 nAcked = seg.ack - m_snd_una;
+    m_snd_una = seg.ack;
+
+    m_rto_base = (m_snd_una == m_snd_nxt) ? 0 : now;
+
+    m_sbuf.ConsumeReadData(nAcked);
+
+    for (uint32 nFree = nAcked; nFree > 0; ) {
+      ASSERT(!m_slist.empty());
+      if (nFree < m_slist.front().len) {
+        m_slist.front().len -= nFree;
+        nFree = 0;
+      } else {
+        if (m_slist.front().len > m_largest) {
+          m_largest = m_slist.front().len;
+        }
+        nFree -= m_slist.front().len;
+        m_slist.pop_front();
+      }
+    }
+
+    if (m_dup_acks >= 3) {
+      if (m_snd_una >= m_recover) { // NewReno
+        uint32 nInFlight = m_snd_nxt - m_snd_una;
+        m_cwnd = rtc::_min(m_ssthresh, nInFlight + m_mss); // (Fast Retransmit)
+#if _DEBUGMSG >= _DBG_NORMAL
+        LOG(LS_INFO) << "exit recovery";
+#endif // _DEBUGMSG
+        m_dup_acks = 0;
+      } else {
+#if _DEBUGMSG >= _DBG_NORMAL
+        LOG(LS_INFO) << "recovery retransmit";
+#endif // _DEBUGMSG
+        if (!transmit(m_slist.begin(), now)) {
+          closedown(ECONNABORTED);
+          return false;
+        }
+        m_cwnd += m_mss - rtc::_min(nAcked, m_cwnd);
+      }
+    } else {
+      m_dup_acks = 0;
+      // Slow start, congestion avoidance
+      if (m_cwnd < m_ssthresh) {
+        m_cwnd += m_mss;
+      } else {
+        m_cwnd += rtc::_max<uint32>(1, m_mss * m_mss / m_cwnd);
+      }
+    }
+  } else if (seg.ack == m_snd_una) {
+    // !?! Note, tcp says don't do this... but otherwise how does a closed window become open?
+    m_snd_wnd = static_cast<uint32>(seg.wnd) << m_swnd_scale;
+
+    // Check duplicate acks
+    if (seg.len > 0) {
+      // it's a dup ack, but with a data payload, so don't modify m_dup_acks
+    } else if (m_snd_una != m_snd_nxt) {
+      m_dup_acks += 1;
+      if (m_dup_acks == 3) { // (Fast Retransmit)
+#if _DEBUGMSG >= _DBG_NORMAL
+        LOG(LS_INFO) << "enter recovery";
+        LOG(LS_INFO) << "recovery retransmit";
+#endif // _DEBUGMSG
+        if (!transmit(m_slist.begin(), now)) {
+          closedown(ECONNABORTED);
+          return false;
+        }
+        m_recover = m_snd_nxt;
+        uint32 nInFlight = m_snd_nxt - m_snd_una;
+        m_ssthresh = rtc::_max(nInFlight / 2, 2 * m_mss);
+        //LOG(LS_INFO) << "m_ssthresh: " << m_ssthresh << "  nInFlight: " << nInFlight << "  m_mss: " << m_mss;
+        m_cwnd = m_ssthresh + 3 * m_mss;
+      } else if (m_dup_acks > 3) {
+        m_cwnd += m_mss;
+      }
+    } else {
+      m_dup_acks = 0;
+    }
+  }
+
+  // !?! A bit hacky
+  if ((m_state == TCP_SYN_RECEIVED) && !bConnect) {
+    m_state = TCP_ESTABLISHED;
+    LOG(LS_INFO) << "State: TCP_ESTABLISHED";
+    adjustMTU();
+    if (m_notify) {
+      m_notify->OnTcpOpen(this);
+    }
+    //notify(evOpen);
+  }
+
+  // If we make room in the send queue, notify the user
+  // The goal it to make sure we always have at least enough data to fill the
+  // window.  We'd like to notify the app when we are halfway to that point.
+  const uint32 kIdealRefillSize = (m_sbuf_len + m_rbuf_len) / 2;
+  size_t snd_buffered = 0;
+  m_sbuf.GetBuffered(&snd_buffered);
+  if (m_bWriteEnable && static_cast<uint32>(snd_buffered) < kIdealRefillSize) {
+    m_bWriteEnable = false;
+    if (m_notify) {
+      m_notify->OnTcpWriteable(this);
+    }
+    //notify(evWrite);
+  }
+
+  // Conditions were acks must be sent:
+  // 1) Segment is too old (they missed an ACK) (immediately)
+  // 2) Segment is too new (we missed a segment) (immediately)
+  // 3) Segment has data (so we need to ACK!) (delayed)
+  // ... so the only time we don't need to ACK, is an empty segment that points to rcv_nxt!
+
+  SendFlags sflags = sfNone;
+  if (seg.seq != m_rcv_nxt) {
+    sflags = sfImmediateAck; // (Fast Recovery)
+  } else if (seg.len != 0) {
+    if (m_ack_delay == 0) {
+      sflags = sfImmediateAck;
+    } else {
+      sflags = sfDelayedAck;
+    }
+  }
+#if _DEBUGMSG >= _DBG_NORMAL
+  if (sflags == sfImmediateAck) {
+    if (seg.seq > m_rcv_nxt) {
+      LOG_F(LS_INFO) << "too new";
+    } else if (seg.seq + seg.len <= m_rcv_nxt) {
+      LOG_F(LS_INFO) << "too old";
+    }
+  }
+#endif // _DEBUGMSG
+
+  // Adjust the incoming segment to fit our receive buffer
+  if (seg.seq < m_rcv_nxt) {
+    uint32 nAdjust = m_rcv_nxt - seg.seq;
+    if (nAdjust < seg.len) {
+      seg.seq += nAdjust;
+      seg.data += nAdjust;
+      seg.len -= nAdjust;
+    } else {
+      seg.len = 0;
+    }
+  }
+
+  size_t available_space = 0;
+  m_rbuf.GetWriteRemaining(&available_space);
+
+  if ((seg.seq + seg.len - m_rcv_nxt) > static_cast<uint32>(available_space)) {
+    uint32 nAdjust = seg.seq + seg.len - m_rcv_nxt - static_cast<uint32>(available_space);
+    if (nAdjust < seg.len) {
+      seg.len -= nAdjust;
+    } else {
+      seg.len = 0;
+    }
+  }
+
+  bool bIgnoreData = (seg.flags & FLAG_CTL) || (m_shutdown != SD_NONE);
+  bool bNewData = false;
+
+  if (seg.len > 0) {
+    if (bIgnoreData) {
+      if (seg.seq == m_rcv_nxt) {
+        m_rcv_nxt += seg.len;
+      }
+    } else {
+      uint32 nOffset = seg.seq - m_rcv_nxt;
+
+      rtc::StreamResult result = m_rbuf.WriteOffset(seg.data, seg.len,
+                                                          nOffset, NULL);
+      ASSERT(result == rtc::SR_SUCCESS);
+      RTC_UNUSED(result);
+
+      if (seg.seq == m_rcv_nxt) {
+        m_rbuf.ConsumeWriteBuffer(seg.len);
+        m_rcv_nxt += seg.len;
+        m_rcv_wnd -= seg.len;
+        bNewData = true;
+
+        RList::iterator it = m_rlist.begin();
+        while ((it != m_rlist.end()) && (it->seq <= m_rcv_nxt)) {
+          if (it->seq + it->len > m_rcv_nxt) {
+            sflags = sfImmediateAck; // (Fast Recovery)
+            uint32 nAdjust = (it->seq + it->len) - m_rcv_nxt;
+#if _DEBUGMSG >= _DBG_NORMAL
+            LOG(LS_INFO) << "Recovered " << nAdjust << " bytes (" << m_rcv_nxt << " -> " << m_rcv_nxt + nAdjust << ")";
+#endif // _DEBUGMSG
+            m_rbuf.ConsumeWriteBuffer(nAdjust);
+            m_rcv_nxt += nAdjust;
+            m_rcv_wnd -= nAdjust;
+          }
+          it = m_rlist.erase(it);
+        }
+      } else {
+#if _DEBUGMSG >= _DBG_NORMAL
+        LOG(LS_INFO) << "Saving " << seg.len << " bytes (" << seg.seq << " -> " << seg.seq + seg.len << ")";
+#endif // _DEBUGMSG
+        RSegment rseg;
+        rseg.seq = seg.seq;
+        rseg.len = seg.len;
+        RList::iterator it = m_rlist.begin();
+        while ((it != m_rlist.end()) && (it->seq < rseg.seq)) {
+          ++it;
+        }
+        m_rlist.insert(it, rseg);
+      }
+    }
+  }
+
+  attemptSend(sflags);
+
+  // If we have new data, notify the user
+  if (bNewData && m_bReadEnable) {
+    m_bReadEnable = false;
+    if (m_notify) {
+      m_notify->OnTcpReadable(this);
+    }
+    //notify(evRead);
+  }
+
+  return true;
+}
+
+bool PseudoTcp::transmit(const SList::iterator& seg, uint32 now) {
+  if (seg->xmit >= ((m_state == TCP_ESTABLISHED) ? 15 : 30)) {
+    LOG_F(LS_VERBOSE) << "too many retransmits";
+    return false;
+  }
+
+  uint32 nTransmit = rtc::_min(seg->len, m_mss);
+
+  while (true) {
+    uint32 seq = seg->seq;
+    uint8 flags = (seg->bCtrl ? FLAG_CTL : 0);
+    IPseudoTcpNotify::WriteResult wres = packet(seq,
+                                                flags,
+                                                seg->seq - m_snd_una,
+                                                nTransmit);
+
+    if (wres == IPseudoTcpNotify::WR_SUCCESS)
+      break;
+
+    if (wres == IPseudoTcpNotify::WR_FAIL) {
+      LOG_F(LS_VERBOSE) << "packet failed";
+      return false;
+    }
+
+    ASSERT(wres == IPseudoTcpNotify::WR_TOO_LARGE);
+
+    while (true) {
+      if (PACKET_MAXIMUMS[m_msslevel + 1] == 0) {
+        LOG_F(LS_VERBOSE) << "MTU too small";
+        return false;
+      }
+      // !?! We need to break up all outstanding and pending packets and then retransmit!?!
+
+      m_mss = PACKET_MAXIMUMS[++m_msslevel] - PACKET_OVERHEAD;
+      m_cwnd = 2 * m_mss; // I added this... haven't researched actual formula
+      if (m_mss < nTransmit) {
+        nTransmit = m_mss;
+        break;
+      }
+    }
+#if _DEBUGMSG >= _DBG_NORMAL
+    LOG(LS_INFO) << "Adjusting mss to " << m_mss << " bytes";
+#endif // _DEBUGMSG
+  }
+
+  if (nTransmit < seg->len) {
+    LOG_F(LS_VERBOSE) << "mss reduced to " << m_mss;
+
+    SSegment subseg(seg->seq + nTransmit, seg->len - nTransmit, seg->bCtrl);
+    //subseg.tstamp = seg->tstamp;
+    subseg.xmit = seg->xmit;
+    seg->len = nTransmit;
+
+    SList::iterator next = seg;
+    m_slist.insert(++next, subseg);
+  }
+
+  if (seg->xmit == 0) {
+    m_snd_nxt += seg->len;
+  }
+  seg->xmit += 1;
+  //seg->tstamp = now;
+  if (m_rto_base == 0) {
+    m_rto_base = now;
+  }
+
+  return true;
+}
+
+void PseudoTcp::attemptSend(SendFlags sflags) {
+  uint32 now = Now();
+
+  if (rtc::TimeDiff(now, m_lastsend) > static_cast<long>(m_rx_rto)) {
+    m_cwnd = m_mss;
+  }
+
+#if _DEBUGMSG
+  bool bFirst = true;
+  RTC_UNUSED(bFirst);
+#endif // _DEBUGMSG
+
+  while (true) {
+    uint32 cwnd = m_cwnd;
+    if ((m_dup_acks == 1) || (m_dup_acks == 2)) { // Limited Transmit
+      cwnd += m_dup_acks * m_mss;
+    }
+    uint32 nWindow = rtc::_min(m_snd_wnd, cwnd);
+    uint32 nInFlight = m_snd_nxt - m_snd_una;
+    uint32 nUseable = (nInFlight < nWindow) ? (nWindow - nInFlight) : 0;
+
+    size_t snd_buffered = 0;
+    m_sbuf.GetBuffered(&snd_buffered);
+    uint32 nAvailable =
+        rtc::_min(static_cast<uint32>(snd_buffered) - nInFlight, m_mss);
+
+    if (nAvailable > nUseable) {
+      if (nUseable * 4 < nWindow) {
+        // RFC 813 - avoid SWS
+        nAvailable = 0;
+      } else {
+        nAvailable = nUseable;
+      }
+    }
+
+#if _DEBUGMSG >= _DBG_VERBOSE
+    if (bFirst) {
+      size_t available_space = 0;
+      m_sbuf.GetWriteRemaining(&available_space);
+
+      bFirst = false;
+      LOG(LS_INFO) << "[cwnd: " << m_cwnd
+                   << "  nWindow: " << nWindow
+                   << "  nInFlight: " << nInFlight
+                   << "  nAvailable: " << nAvailable
+                   << "  nQueued: " << snd_buffered
+                   << "  nEmpty: " << available_space
+                   << "  ssthresh: " << m_ssthresh << "]";
+    }
+#endif // _DEBUGMSG
+
+    if (nAvailable == 0) {
+      if (sflags == sfNone)
+        return;
+
+      // If this is an immediate ack, or the second delayed ack
+      if ((sflags == sfImmediateAck) || m_t_ack) {
+        packet(m_snd_nxt, 0, 0, 0);
+      } else {
+        m_t_ack = Now();
+      }
+      return;
+    }
+
+    // Nagle's algorithm.
+    // If there is data already in-flight, and we haven't a full segment of
+    // data ready to send then hold off until we get more to send, or the
+    // in-flight data is acknowledged.
+    if (m_use_nagling && (m_snd_nxt > m_snd_una) && (nAvailable < m_mss))  {
+      return;
+    }
+
+    // Find the next segment to transmit
+    SList::iterator it = m_slist.begin();
+    while (it->xmit > 0) {
+      ++it;
+      ASSERT(it != m_slist.end());
+    }
+    SList::iterator seg = it;
+
+    // If the segment is too large, break it into two
+    if (seg->len > nAvailable) {
+      SSegment subseg(seg->seq + nAvailable, seg->len - nAvailable, seg->bCtrl);
+      seg->len = nAvailable;
+      m_slist.insert(++it, subseg);
+    }
+
+    if (!transmit(seg, now)) {
+      LOG_F(LS_VERBOSE) << "transmit failed";
+      // TODO: consider closing socket
+      return;
+    }
+
+    sflags = sfNone;
+  }
+}
+
+void
+PseudoTcp::closedown(uint32 err) {
+  LOG(LS_INFO) << "State: TCP_CLOSED";
+  m_state = TCP_CLOSED;
+  if (m_notify) {
+    m_notify->OnTcpClosed(this, err);
+  }
+  //notify(evClose, err);
+}
+
+void
+PseudoTcp::adjustMTU() {
+  // Determine our current mss level, so that we can adjust appropriately later
+  for (m_msslevel = 0; PACKET_MAXIMUMS[m_msslevel + 1] > 0; ++m_msslevel) {
+    if (static_cast<uint16>(PACKET_MAXIMUMS[m_msslevel]) <= m_mtu_advise) {
+      break;
+    }
+  }
+  m_mss = m_mtu_advise - PACKET_OVERHEAD;
+  // !?! Should we reset m_largest here?
+#if _DEBUGMSG >= _DBG_NORMAL
+  LOG(LS_INFO) << "Adjusting mss to " << m_mss << " bytes";
+#endif // _DEBUGMSG
+  // Enforce minimums on ssthresh and cwnd
+  m_ssthresh = rtc::_max(m_ssthresh, 2 * m_mss);
+  m_cwnd = rtc::_max(m_cwnd, m_mss);
+}
+
+bool
+PseudoTcp::isReceiveBufferFull() const {
+  size_t available_space = 0;
+  m_rbuf.GetWriteRemaining(&available_space);
+  return !available_space;
+}
+
+void
+PseudoTcp::disableWindowScale() {
+  m_support_wnd_scale = false;
+}
+
+void
+PseudoTcp::queueConnectMessage() {
+  rtc::ByteBuffer buf(rtc::ByteBuffer::ORDER_NETWORK);
+
+  buf.WriteUInt8(CTL_CONNECT);
+  if (m_support_wnd_scale) {
+    buf.WriteUInt8(TCP_OPT_WND_SCALE);
+    buf.WriteUInt8(1);
+    buf.WriteUInt8(m_rwnd_scale);
+  }
+  m_snd_wnd = static_cast<uint32>(buf.Length());
+  queue(buf.Data(), static_cast<uint32>(buf.Length()), true);
+}
+
+void
+PseudoTcp::parseOptions(const char* data, uint32 len) {
+  std::set<uint8> options_specified;
+
+  // See http://www.freesoft.org/CIE/Course/Section4/8.htm for
+  // parsing the options list.
+  rtc::ByteBuffer buf(data, len);
+  while (buf.Length()) {
+    uint8 kind = TCP_OPT_EOL;
+    buf.ReadUInt8(&kind);
+
+    if (kind == TCP_OPT_EOL) {
+      // End of option list.
+      break;
+    } else if (kind == TCP_OPT_NOOP) {
+      // No op.
+      continue;
+    }
+
+    // Length of this option.
+    ASSERT(len != 0);
+    RTC_UNUSED(len);
+    uint8 opt_len = 0;
+    buf.ReadUInt8(&opt_len);
+
+    // Content of this option.
+    if (opt_len <= buf.Length()) {
+      applyOption(kind, buf.Data(), opt_len);
+      buf.Consume(opt_len);
+    } else {
+      LOG(LS_ERROR) << "Invalid option length received.";
+      return;
+    }
+    options_specified.insert(kind);
+  }
+
+  if (options_specified.find(TCP_OPT_WND_SCALE) == options_specified.end()) {
+    LOG(LS_WARNING) << "Peer doesn't support window scaling";
+
+    if (m_rwnd_scale > 0) {
+      // Peer doesn't support TCP options and window scaling.
+      // Revert receive buffer size to default value.
+      resizeReceiveBuffer(DEFAULT_RCV_BUF_SIZE);
+      m_swnd_scale = 0;
+    }
+  }
+}
+
+void
+PseudoTcp::applyOption(char kind, const char* data, uint32 len) {
+  if (kind == TCP_OPT_MSS) {
+    LOG(LS_WARNING) << "Peer specified MSS option which is not supported.";
+    // TODO: Implement.
+  } else if (kind == TCP_OPT_WND_SCALE) {
+    // Window scale factor.
+    // http://www.ietf.org/rfc/rfc1323.txt
+    if (len != 1) {
+      LOG_F(WARNING) << "Invalid window scale option received.";
+      return;
+    }
+    applyWindowScaleOption(data[0]);
+  }
+}
+
+void
+PseudoTcp::applyWindowScaleOption(uint8 scale_factor) {
+  m_swnd_scale = scale_factor;
+}
+
+void
+PseudoTcp::resizeSendBuffer(uint32 new_size) {
+  m_sbuf_len = new_size;
+  m_sbuf.SetCapacity(new_size);
+}
+
+void
+PseudoTcp::resizeReceiveBuffer(uint32 new_size) {
+  uint8 scale_factor = 0;
+
+  // Determine the scale factor such that the scaled window size can fit
+  // in a 16-bit unsigned integer.
+  while (new_size > 0xFFFF) {
+    ++scale_factor;
+    new_size >>= 1;
+  }
+
+  // Determine the proper size of the buffer.
+  new_size <<= scale_factor;
+  bool result = m_rbuf.SetCapacity(new_size);
+
+  // Make sure the new buffer is large enough to contain data in the old
+  // buffer. This should always be true because this method is called either
+  // before connection is established or when peers are exchanging connect
+  // messages.
+  ASSERT(result);
+  RTC_UNUSED(result);
+  m_rbuf_len = new_size;
+  m_rwnd_scale = scale_factor;
+  m_ssthresh = new_size;
+
+  size_t available_space = 0;
+  m_rbuf.GetWriteRemaining(&available_space);
+  m_rcv_wnd = static_cast<uint32>(available_space);
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/pseudotcp.h b/webrtc/p2p/base/pseudotcp.h
new file mode 100644
index 0000000..b2cfcb7
--- /dev/null
+++ b/webrtc/p2p/base/pseudotcp.h
@@ -0,0 +1,241 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_PSEUDOTCP_H_
+#define WEBRTC_P2P_BASE_PSEUDOTCP_H_
+
+#include <list>
+
+#include "webrtc/base/basictypes.h"
+#include "webrtc/base/stream.h"
+
+namespace cricket {
+
+//////////////////////////////////////////////////////////////////////
+// IPseudoTcpNotify
+//////////////////////////////////////////////////////////////////////
+
+class PseudoTcp;
+
+class IPseudoTcpNotify {
+ public:
+  // Notification of tcp events
+  virtual void OnTcpOpen(PseudoTcp* tcp) = 0;
+  virtual void OnTcpReadable(PseudoTcp* tcp) = 0;
+  virtual void OnTcpWriteable(PseudoTcp* tcp) = 0;
+  virtual void OnTcpClosed(PseudoTcp* tcp, uint32 error) = 0;
+
+  // Write the packet onto the network
+  enum WriteResult { WR_SUCCESS, WR_TOO_LARGE, WR_FAIL };
+  virtual WriteResult TcpWritePacket(PseudoTcp* tcp,
+                                     const char* buffer, size_t len) = 0;
+
+ protected:
+  virtual ~IPseudoTcpNotify() {}
+};
+
+//////////////////////////////////////////////////////////////////////
+// PseudoTcp
+//////////////////////////////////////////////////////////////////////
+
+class PseudoTcp {
+ public:
+  static uint32 Now();
+
+  PseudoTcp(IPseudoTcpNotify* notify, uint32 conv);
+  virtual ~PseudoTcp();
+
+  int Connect();
+  int Recv(char* buffer, size_t len);
+  int Send(const char* buffer, size_t len);
+  void Close(bool force);
+  int GetError();
+
+  enum TcpState {
+    TCP_LISTEN, TCP_SYN_SENT, TCP_SYN_RECEIVED, TCP_ESTABLISHED, TCP_CLOSED
+  };
+  TcpState State() const { return m_state; }
+
+  // Call this when the PMTU changes.
+  void NotifyMTU(uint16 mtu);
+
+  // Call this based on timeout value returned from GetNextClock.
+  // It's ok to call this too frequently.
+  void NotifyClock(uint32 now);
+
+  // Call this whenever a packet arrives.
+  // Returns true if the packet was processed successfully.
+  bool NotifyPacket(const char * buffer, size_t len);
+
+  // Call this to determine the next time NotifyClock should be called.
+  // Returns false if the socket is ready to be destroyed.
+  bool GetNextClock(uint32 now, long& timeout);
+
+  // Call these to get/set option values to tailor this PseudoTcp
+  // instance's behaviour for the kind of data it will carry.
+  // If an unrecognized option is set or got, an assertion will fire.
+  //
+  // Setting options for OPT_RCVBUF or OPT_SNDBUF after Connect() is called
+  // will result in an assertion.
+  enum Option {
+    OPT_NODELAY,      // Whether to enable Nagle's algorithm (0 == off)
+    OPT_ACKDELAY,     // The Delayed ACK timeout (0 == off).
+    OPT_RCVBUF,       // Set the receive buffer size, in bytes.
+    OPT_SNDBUF,       // Set the send buffer size, in bytes.
+  };
+  void GetOption(Option opt, int* value);
+  void SetOption(Option opt, int value);
+
+  // Returns current congestion window in bytes.
+  uint32 GetCongestionWindow() const;
+
+  // Returns amount of data in bytes that has been sent, but haven't
+  // been acknowledged.
+  uint32 GetBytesInFlight() const;
+
+  // Returns number of bytes that were written in buffer and haven't
+  // been sent.
+  uint32 GetBytesBufferedNotSent() const;
+
+  // Returns current round-trip time estimate in milliseconds.
+  uint32 GetRoundTripTimeEstimateMs() const;
+
+ protected:
+  enum SendFlags { sfNone, sfDelayedAck, sfImmediateAck };
+
+  struct Segment {
+    uint32 conv, seq, ack;
+    uint8 flags;
+    uint16 wnd;
+    const char * data;
+    uint32 len;
+    uint32 tsval, tsecr;
+  };
+
+  struct SSegment {
+    SSegment(uint32 s, uint32 l, bool c)
+        : seq(s), len(l), /*tstamp(0),*/ xmit(0), bCtrl(c) {
+    }
+    uint32 seq, len;
+    //uint32 tstamp;
+    uint8 xmit;
+    bool bCtrl;
+  };
+  typedef std::list<SSegment> SList;
+
+  struct RSegment {
+    uint32 seq, len;
+  };
+
+  uint32 queue(const char* data, uint32 len, bool bCtrl);
+
+  // Creates a packet and submits it to the network. This method can either
+  // send payload or just an ACK packet.
+  //
+  // |seq| is the sequence number of this packet.
+  // |flags| is the flags for sending this packet.
+  // |offset| is the offset to read from |m_sbuf|.
+  // |len| is the number of bytes to read from |m_sbuf| as payload. If this
+  // value is 0 then this is an ACK packet, otherwise this packet has payload.
+  IPseudoTcpNotify::WriteResult packet(uint32 seq, uint8 flags,
+                                       uint32 offset, uint32 len);
+  bool parse(const uint8* buffer, uint32 size);
+
+  void attemptSend(SendFlags sflags = sfNone);
+
+  void closedown(uint32 err = 0);
+
+  bool clock_check(uint32 now, long& nTimeout);
+
+  bool process(Segment& seg);
+  bool transmit(const SList::iterator& seg, uint32 now);
+
+  void adjustMTU();
+
+ protected:
+  // This method is used in test only to query receive buffer state.
+  bool isReceiveBufferFull() const;
+
+  // This method is only used in tests, to disable window scaling
+  // support for testing backward compatibility.
+  void disableWindowScale();
+
+ private:
+  // Queue the connect message with TCP options.
+  void queueConnectMessage();
+
+  // Parse TCP options in the header.
+  void parseOptions(const char* data, uint32 len);
+
+  // Apply a TCP option that has been read from the header.
+  void applyOption(char kind, const char* data, uint32 len);
+
+  // Apply window scale option.
+  void applyWindowScaleOption(uint8 scale_factor);
+
+  // Resize the send buffer with |new_size| in bytes.
+  void resizeSendBuffer(uint32 new_size);
+
+  // Resize the receive buffer with |new_size| in bytes. This call adjusts
+  // window scale factor |m_swnd_scale| accordingly.
+  void resizeReceiveBuffer(uint32 new_size);
+
+  IPseudoTcpNotify* m_notify;
+  enum Shutdown { SD_NONE, SD_GRACEFUL, SD_FORCEFUL } m_shutdown;
+  int m_error;
+
+  // TCB data
+  TcpState m_state;
+  uint32 m_conv;
+  bool m_bReadEnable, m_bWriteEnable, m_bOutgoing;
+  uint32 m_lasttraffic;
+
+  // Incoming data
+  typedef std::list<RSegment> RList;
+  RList m_rlist;
+  uint32 m_rbuf_len, m_rcv_nxt, m_rcv_wnd, m_lastrecv;
+  uint8 m_rwnd_scale;  // Window scale factor.
+  rtc::FifoBuffer m_rbuf;
+
+  // Outgoing data
+  SList m_slist;
+  uint32 m_sbuf_len, m_snd_nxt, m_snd_wnd, m_lastsend, m_snd_una;
+  uint8 m_swnd_scale;  // Window scale factor.
+  rtc::FifoBuffer m_sbuf;
+
+  // Maximum segment size, estimated protocol level, largest segment sent
+  uint32 m_mss, m_msslevel, m_largest, m_mtu_advise;
+  // Retransmit timer
+  uint32 m_rto_base;
+
+  // Timestamp tracking
+  uint32 m_ts_recent, m_ts_lastack;
+
+  // Round-trip calculation
+  uint32 m_rx_rttvar, m_rx_srtt, m_rx_rto;
+
+  // Congestion avoidance, Fast retransmit/recovery, Delayed ACKs
+  uint32 m_ssthresh, m_cwnd;
+  uint8 m_dup_acks;
+  uint32 m_recover;
+  uint32 m_t_ack;
+
+  // Configuration options
+  bool m_use_nagling;
+  uint32 m_ack_delay;
+
+  // This is used by unit tests to test backward compatibility of
+  // PseudoTcp implementations that don't support window scaling.
+  bool m_support_wnd_scale;
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_PSEUDOTCP_H_
diff --git a/webrtc/p2p/base/pseudotcp_unittest.cc b/webrtc/p2p/base/pseudotcp_unittest.cc
new file mode 100644
index 0000000..f5ea7ace
--- /dev/null
+++ b/webrtc/p2p/base/pseudotcp_unittest.cc
@@ -0,0 +1,841 @@
+/*
+ *  Copyright 2011 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <vector>
+
+#include "webrtc/p2p/base/pseudotcp.h"
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/helpers.h"
+#include "webrtc/base/messagehandler.h"
+#include "webrtc/base/stream.h"
+#include "webrtc/base/thread.h"
+#include "webrtc/base/timeutils.h"
+
+using cricket::PseudoTcp;
+
+static const int kConnectTimeoutMs = 10000;  // ~3 * default RTO of 3000ms
+static const int kTransferTimeoutMs = 15000;
+static const int kBlockSize = 4096;
+
+class PseudoTcpForTest : public cricket::PseudoTcp {
+ public:
+  PseudoTcpForTest(cricket::IPseudoTcpNotify* notify, uint32 conv)
+      : PseudoTcp(notify, conv) {
+  }
+
+  bool isReceiveBufferFull() const {
+    return PseudoTcp::isReceiveBufferFull();
+  }
+
+  void disableWindowScale() {
+    PseudoTcp::disableWindowScale();
+  }
+};
+
+class PseudoTcpTestBase : public testing::Test,
+                      public rtc::MessageHandler,
+                      public cricket::IPseudoTcpNotify {
+ public:
+  PseudoTcpTestBase()
+      : local_(this, 1),
+        remote_(this, 1),
+        have_connected_(false),
+        have_disconnected_(false),
+        local_mtu_(65535),
+        remote_mtu_(65535),
+        delay_(0),
+        loss_(0) {
+    // Set use of the test RNG to get predictable loss patterns.
+    rtc::SetRandomTestMode(true);
+  }
+  ~PseudoTcpTestBase() {
+    // Put it back for the next test.
+    rtc::SetRandomTestMode(false);
+  }
+  void SetLocalMtu(int mtu) {
+    local_.NotifyMTU(mtu);
+    local_mtu_ = mtu;
+  }
+  void SetRemoteMtu(int mtu) {
+    remote_.NotifyMTU(mtu);
+    remote_mtu_ = mtu;
+  }
+  void SetDelay(int delay) {
+    delay_ = delay;
+  }
+  void SetLoss(int percent) {
+    loss_ = percent;
+  }
+  void SetOptNagling(bool enable_nagles) {
+    local_.SetOption(PseudoTcp::OPT_NODELAY, !enable_nagles);
+    remote_.SetOption(PseudoTcp::OPT_NODELAY, !enable_nagles);
+  }
+  void SetOptAckDelay(int ack_delay) {
+    local_.SetOption(PseudoTcp::OPT_ACKDELAY, ack_delay);
+    remote_.SetOption(PseudoTcp::OPT_ACKDELAY, ack_delay);
+  }
+  void SetOptSndBuf(int size) {
+    local_.SetOption(PseudoTcp::OPT_SNDBUF, size);
+    remote_.SetOption(PseudoTcp::OPT_SNDBUF, size);
+  }
+  void SetRemoteOptRcvBuf(int size) {
+    remote_.SetOption(PseudoTcp::OPT_RCVBUF, size);
+  }
+  void SetLocalOptRcvBuf(int size) {
+    local_.SetOption(PseudoTcp::OPT_RCVBUF, size);
+  }
+  void DisableRemoteWindowScale() {
+    remote_.disableWindowScale();
+  }
+  void DisableLocalWindowScale() {
+    local_.disableWindowScale();
+  }
+
+ protected:
+  int Connect() {
+    int ret = local_.Connect();
+    if (ret == 0) {
+      UpdateLocalClock();
+    }
+    return ret;
+  }
+  void Close() {
+    local_.Close(false);
+    UpdateLocalClock();
+  }
+
+  enum { MSG_LPACKET, MSG_RPACKET, MSG_LCLOCK, MSG_RCLOCK, MSG_IOCOMPLETE,
+         MSG_WRITE};
+  virtual void OnTcpOpen(PseudoTcp* tcp) {
+    // Consider ourselves connected when the local side gets OnTcpOpen.
+    // OnTcpWriteable isn't fired at open, so we trigger it now.
+    LOG(LS_VERBOSE) << "Opened";
+    if (tcp == &local_) {
+      have_connected_ = true;
+      OnTcpWriteable(tcp);
+    }
+  }
+  // Test derived from the base should override
+  //   virtual void OnTcpReadable(PseudoTcp* tcp)
+  // and
+  //   virtual void OnTcpWritable(PseudoTcp* tcp)
+  virtual void OnTcpClosed(PseudoTcp* tcp, uint32 error) {
+    // Consider ourselves closed when the remote side gets OnTcpClosed.
+    // TODO: OnTcpClosed is only ever notified in case of error in
+    // the current implementation.  Solicited close is not (yet) supported.
+    LOG(LS_VERBOSE) << "Closed";
+    EXPECT_EQ(0U, error);
+    if (tcp == &remote_) {
+      have_disconnected_ = true;
+    }
+  }
+  virtual WriteResult TcpWritePacket(PseudoTcp* tcp,
+                                     const char* buffer, size_t len) {
+    // Randomly drop the desired percentage of packets.
+    // Also drop packets that are larger than the configured MTU.
+    if (rtc::CreateRandomId() % 100 < static_cast<uint32>(loss_)) {
+      LOG(LS_VERBOSE) << "Randomly dropping packet, size=" << len;
+    } else if (len > static_cast<size_t>(
+        rtc::_min(local_mtu_, remote_mtu_))) {
+      LOG(LS_VERBOSE) << "Dropping packet that exceeds path MTU, size=" << len;
+    } else {
+      int id = (tcp == &local_) ? MSG_RPACKET : MSG_LPACKET;
+      std::string packet(buffer, len);
+      rtc::Thread::Current()->PostDelayed(delay_, this, id,
+          rtc::WrapMessageData(packet));
+    }
+    return WR_SUCCESS;
+  }
+
+  void UpdateLocalClock() { UpdateClock(&local_, MSG_LCLOCK); }
+  void UpdateRemoteClock() { UpdateClock(&remote_, MSG_RCLOCK); }
+  void UpdateClock(PseudoTcp* tcp, uint32 message) {
+    long interval = 0;  // NOLINT
+    tcp->GetNextClock(PseudoTcp::Now(), interval);
+    interval = rtc::_max<int>(interval, 0L);  // sometimes interval is < 0
+    rtc::Thread::Current()->Clear(this, message);
+    rtc::Thread::Current()->PostDelayed(interval, this, message);
+  }
+
+  virtual void OnMessage(rtc::Message* message) {
+    switch (message->message_id) {
+      case MSG_LPACKET: {
+        const std::string& s(
+            rtc::UseMessageData<std::string>(message->pdata));
+        local_.NotifyPacket(s.c_str(), s.size());
+        UpdateLocalClock();
+        break;
+      }
+      case MSG_RPACKET: {
+        const std::string& s(
+            rtc::UseMessageData<std::string>(message->pdata));
+        remote_.NotifyPacket(s.c_str(), s.size());
+        UpdateRemoteClock();
+        break;
+      }
+      case MSG_LCLOCK:
+        local_.NotifyClock(PseudoTcp::Now());
+        UpdateLocalClock();
+        break;
+      case MSG_RCLOCK:
+        remote_.NotifyClock(PseudoTcp::Now());
+        UpdateRemoteClock();
+        break;
+      default:
+        break;
+    }
+    delete message->pdata;
+  }
+
+  PseudoTcpForTest local_;
+  PseudoTcpForTest remote_;
+  rtc::MemoryStream send_stream_;
+  rtc::MemoryStream recv_stream_;
+  bool have_connected_;
+  bool have_disconnected_;
+  int local_mtu_;
+  int remote_mtu_;
+  int delay_;
+  int loss_;
+};
+
+class PseudoTcpTest : public PseudoTcpTestBase {
+ public:
+  void TestTransfer(int size) {
+    uint32 start, elapsed;
+    size_t received;
+    // Create some dummy data to send.
+    send_stream_.ReserveSize(size);
+    for (int i = 0; i < size; ++i) {
+      char ch = static_cast<char>(i);
+      send_stream_.Write(&ch, 1, NULL, NULL);
+    }
+    send_stream_.Rewind();
+    // Prepare the receive stream.
+    recv_stream_.ReserveSize(size);
+    // Connect and wait until connected.
+    start = rtc::Time();
+    EXPECT_EQ(0, Connect());
+    EXPECT_TRUE_WAIT(have_connected_, kConnectTimeoutMs);
+    // Sending will start from OnTcpWriteable and complete when all data has
+    // been received.
+    EXPECT_TRUE_WAIT(have_disconnected_, kTransferTimeoutMs);
+    elapsed = rtc::TimeSince(start);
+    recv_stream_.GetSize(&received);
+    // Ensure we closed down OK and we got the right data.
+    // TODO: Ensure the errors are cleared properly.
+    //EXPECT_EQ(0, local_.GetError());
+    //EXPECT_EQ(0, remote_.GetError());
+    EXPECT_EQ(static_cast<size_t>(size), received);
+    EXPECT_EQ(0, memcmp(send_stream_.GetBuffer(),
+                        recv_stream_.GetBuffer(), size));
+    LOG(LS_INFO) << "Transferred " << received << " bytes in " << elapsed
+                 << " ms (" << size * 8 / elapsed << " Kbps)";
+  }
+
+ private:
+  // IPseudoTcpNotify interface
+
+  virtual void OnTcpReadable(PseudoTcp* tcp) {
+    // Stream bytes to the recv stream as they arrive.
+    if (tcp == &remote_) {
+      ReadData();
+
+      // TODO: OnTcpClosed() is currently only notified on error -
+      // there is no on-the-wire equivalent of TCP FIN.
+      // So we fake the notification when all the data has been read.
+      size_t received, required;
+      recv_stream_.GetPosition(&received);
+      send_stream_.GetSize(&required);
+      if (received == required)
+        OnTcpClosed(&remote_, 0);
+    }
+  }
+  virtual void OnTcpWriteable(PseudoTcp* tcp) {
+    // Write bytes from the send stream when we can.
+    // Shut down when we've sent everything.
+    if (tcp == &local_) {
+      LOG(LS_VERBOSE) << "Flow Control Lifted";
+      bool done;
+      WriteData(&done);
+      if (done) {
+        Close();
+      }
+    }
+  }
+
+  void ReadData() {
+    char block[kBlockSize];
+    size_t position;
+    int rcvd;
+    do {
+      rcvd = remote_.Recv(block, sizeof(block));
+      if (rcvd != -1) {
+        recv_stream_.Write(block, rcvd, NULL, NULL);
+        recv_stream_.GetPosition(&position);
+        LOG(LS_VERBOSE) << "Received: " << position;
+      }
+    } while (rcvd > 0);
+  }
+  void WriteData(bool* done) {
+    size_t position, tosend;
+    int sent;
+    char block[kBlockSize];
+    do {
+      send_stream_.GetPosition(&position);
+      if (send_stream_.Read(block, sizeof(block), &tosend, NULL) !=
+          rtc::SR_EOS) {
+        sent = local_.Send(block, tosend);
+        UpdateLocalClock();
+        if (sent != -1) {
+          send_stream_.SetPosition(position + sent);
+          LOG(LS_VERBOSE) << "Sent: " << position + sent;
+        } else {
+          send_stream_.SetPosition(position);
+          LOG(LS_VERBOSE) << "Flow Controlled";
+        }
+      } else {
+        sent = static_cast<int>(tosend = 0);
+      }
+    } while (sent > 0);
+    *done = (tosend == 0);
+  }
+
+ private:
+  rtc::MemoryStream send_stream_;
+  rtc::MemoryStream recv_stream_;
+};
+
+
+class PseudoTcpTestPingPong : public PseudoTcpTestBase {
+ public:
+  PseudoTcpTestPingPong()
+      : iterations_remaining_(0),
+	sender_(NULL),
+	receiver_(NULL),
+	bytes_per_send_(0) {
+  }
+  void SetBytesPerSend(int bytes) {
+    bytes_per_send_ = bytes;
+  }
+  void TestPingPong(int size, int iterations) {
+    uint32 start, elapsed;
+    iterations_remaining_ = iterations;
+    receiver_ = &remote_;
+    sender_ = &local_;
+    // Create some dummy data to send.
+    send_stream_.ReserveSize(size);
+    for (int i = 0; i < size; ++i) {
+      char ch = static_cast<char>(i);
+      send_stream_.Write(&ch, 1, NULL, NULL);
+    }
+    send_stream_.Rewind();
+    // Prepare the receive stream.
+    recv_stream_.ReserveSize(size);
+    // Connect and wait until connected.
+    start = rtc::Time();
+    EXPECT_EQ(0, Connect());
+    EXPECT_TRUE_WAIT(have_connected_, kConnectTimeoutMs);
+    // Sending will start from OnTcpWriteable and stop when the required
+    // number of iterations have completed.
+    EXPECT_TRUE_WAIT(have_disconnected_, kTransferTimeoutMs);
+    elapsed = rtc::TimeSince(start);
+    LOG(LS_INFO) << "Performed " << iterations << " pings in "
+                 << elapsed << " ms";
+  }
+
+ private:
+  // IPseudoTcpNotify interface
+
+  virtual void OnTcpReadable(PseudoTcp* tcp) {
+    if (tcp != receiver_) {
+      LOG_F(LS_ERROR) << "unexpected OnTcpReadable";
+      return;
+    }
+    // Stream bytes to the recv stream as they arrive.
+    ReadData();
+    // If we've received the desired amount of data, rewind things
+    // and send it back the other way!
+    size_t position, desired;
+    recv_stream_.GetPosition(&position);
+    send_stream_.GetSize(&desired);
+    if (position == desired) {
+      if (receiver_ == &local_ && --iterations_remaining_ == 0) {
+        Close();
+        // TODO: Fake OnTcpClosed() on the receiver for now.
+        OnTcpClosed(&remote_, 0);
+        return;
+      }
+      PseudoTcp* tmp = receiver_;
+      receiver_ = sender_;
+      sender_ = tmp;
+      recv_stream_.Rewind();
+      send_stream_.Rewind();
+      OnTcpWriteable(sender_);
+    }
+  }
+  virtual void OnTcpWriteable(PseudoTcp* tcp) {
+    if (tcp != sender_)
+      return;
+    // Write bytes from the send stream when we can.
+    // Shut down when we've sent everything.
+    LOG(LS_VERBOSE) << "Flow Control Lifted";
+    WriteData();
+  }
+
+  void ReadData() {
+    char block[kBlockSize];
+    size_t position;
+    int rcvd;
+    do {
+      rcvd = receiver_->Recv(block, sizeof(block));
+      if (rcvd != -1) {
+        recv_stream_.Write(block, rcvd, NULL, NULL);
+        recv_stream_.GetPosition(&position);
+        LOG(LS_VERBOSE) << "Received: " << position;
+      }
+    } while (rcvd > 0);
+  }
+  void WriteData() {
+    size_t position, tosend;
+    int sent;
+    char block[kBlockSize];
+    do {
+      send_stream_.GetPosition(&position);
+      tosend = bytes_per_send_ ? bytes_per_send_ : sizeof(block);
+      if (send_stream_.Read(block, tosend, &tosend, NULL) !=
+          rtc::SR_EOS) {
+        sent = sender_->Send(block, tosend);
+        UpdateLocalClock();
+        if (sent != -1) {
+          send_stream_.SetPosition(position + sent);
+          LOG(LS_VERBOSE) << "Sent: " << position + sent;
+        } else {
+          send_stream_.SetPosition(position);
+          LOG(LS_VERBOSE) << "Flow Controlled";
+        }
+      } else {
+        sent = static_cast<int>(tosend = 0);
+      }
+    } while (sent > 0);
+  }
+
+ private:
+  int iterations_remaining_;
+  PseudoTcp* sender_;
+  PseudoTcp* receiver_;
+  int bytes_per_send_;
+};
+
+// Fill the receiver window until it is full, drain it and then
+// fill it with the same amount. This is to test that receiver window
+// contracts and enlarges correctly.
+class PseudoTcpTestReceiveWindow : public PseudoTcpTestBase {
+ public:
+  // Not all the data are transfered, |size| just need to be big enough
+  // to fill up the receiver window twice.
+  void TestTransfer(int size) {
+    // Create some dummy data to send.
+    send_stream_.ReserveSize(size);
+    for (int i = 0; i < size; ++i) {
+      char ch = static_cast<char>(i);
+      send_stream_.Write(&ch, 1, NULL, NULL);
+    }
+    send_stream_.Rewind();
+
+    // Prepare the receive stream.
+    recv_stream_.ReserveSize(size);
+
+    // Connect and wait until connected.
+    EXPECT_EQ(0, Connect());
+    EXPECT_TRUE_WAIT(have_connected_, kConnectTimeoutMs);
+
+    rtc::Thread::Current()->Post(this, MSG_WRITE);
+    EXPECT_TRUE_WAIT(have_disconnected_, kTransferTimeoutMs);
+
+    ASSERT_EQ(2u, send_position_.size());
+    ASSERT_EQ(2u, recv_position_.size());
+
+    const size_t estimated_recv_window = EstimateReceiveWindowSize();
+
+    // The difference in consecutive send positions should equal the
+    // receive window size or match very closely. This verifies that receive
+    // window is open after receiver drained all the data.
+    const size_t send_position_diff = send_position_[1] - send_position_[0];
+    EXPECT_GE(1024u, estimated_recv_window - send_position_diff);
+
+    // Receiver drained the receive window twice.
+    EXPECT_EQ(2 * estimated_recv_window, recv_position_[1]);
+  }
+
+  virtual void OnMessage(rtc::Message* message) {
+    int message_id = message->message_id;
+    PseudoTcpTestBase::OnMessage(message);
+
+    switch (message_id) {
+      case MSG_WRITE: {
+        WriteData();
+        break;
+      }
+      default:
+        break;
+    }
+  }
+
+  uint32 EstimateReceiveWindowSize() const {
+    return static_cast<uint32>(recv_position_[0]);
+  }
+
+  uint32 EstimateSendWindowSize() const {
+    return static_cast<uint32>(send_position_[0] - recv_position_[0]);
+  }
+
+ private:
+  // IPseudoTcpNotify interface
+  virtual void OnTcpReadable(PseudoTcp* tcp) {
+  }
+
+  virtual void OnTcpWriteable(PseudoTcp* tcp) {
+  }
+
+  void ReadUntilIOPending() {
+    char block[kBlockSize];
+    size_t position;
+    int rcvd;
+
+    do {
+      rcvd = remote_.Recv(block, sizeof(block));
+      if (rcvd != -1) {
+        recv_stream_.Write(block, rcvd, NULL, NULL);
+        recv_stream_.GetPosition(&position);
+        LOG(LS_VERBOSE) << "Received: " << position;
+      }
+    } while (rcvd > 0);
+
+    recv_stream_.GetPosition(&position);
+    recv_position_.push_back(position);
+
+    // Disconnect if we have done two transfers.
+    if (recv_position_.size() == 2u) {
+      Close();
+      OnTcpClosed(&remote_, 0);
+    } else {
+      WriteData();
+    }
+  }
+
+  void WriteData() {
+    size_t position, tosend;
+    int sent;
+    char block[kBlockSize];
+    do {
+      send_stream_.GetPosition(&position);
+      if (send_stream_.Read(block, sizeof(block), &tosend, NULL) !=
+          rtc::SR_EOS) {
+        sent = local_.Send(block, tosend);
+        UpdateLocalClock();
+        if (sent != -1) {
+          send_stream_.SetPosition(position + sent);
+          LOG(LS_VERBOSE) << "Sent: " << position + sent;
+        } else {
+          send_stream_.SetPosition(position);
+          LOG(LS_VERBOSE) << "Flow Controlled";
+        }
+      } else {
+        sent = static_cast<int>(tosend = 0);
+      }
+    } while (sent > 0);
+    // At this point, we've filled up the available space in the send queue.
+
+    int message_queue_size =
+        static_cast<int>(rtc::Thread::Current()->size());
+    // The message queue will always have at least 2 messages, an RCLOCK and
+    // an LCLOCK, since they are added back on the delay queue at the same time
+    // they are pulled off and therefore are never really removed.
+    if (message_queue_size > 2) {
+      // If there are non-clock messages remaining, attempt to continue sending
+      // after giving those messages time to process, which should free up the
+      // send buffer.
+      rtc::Thread::Current()->PostDelayed(10, this, MSG_WRITE);
+    } else {
+      if (!remote_.isReceiveBufferFull()) {
+        LOG(LS_ERROR) << "This shouldn't happen - the send buffer is full, "
+                      << "the receive buffer is not, and there are no "
+                      << "remaining messages to process.";
+      }
+      send_stream_.GetPosition(&position);
+      send_position_.push_back(position);
+
+      // Drain the receiver buffer.
+      ReadUntilIOPending();
+    }
+  }
+
+ private:
+  rtc::MemoryStream send_stream_;
+  rtc::MemoryStream recv_stream_;
+
+  std::vector<size_t> send_position_;
+  std::vector<size_t> recv_position_;
+};
+
+// Basic end-to-end data transfer tests
+
+// Test the normal case of sending data from one side to the other.
+TEST_F(PseudoTcpTest, TestSend) {
+  SetLocalMtu(1500);
+  SetRemoteMtu(1500);
+  TestTransfer(1000000);
+}
+
+// Test sending data with a 50 ms RTT. Transmission should take longer due
+// to a slower ramp-up in send rate.
+TEST_F(PseudoTcpTest, TestSendWithDelay) {
+  SetLocalMtu(1500);
+  SetRemoteMtu(1500);
+  SetDelay(50);
+  TestTransfer(1000000);
+}
+
+// Test sending data with packet loss. Transmission should take much longer due
+// to send back-off when loss occurs.
+TEST_F(PseudoTcpTest, TestSendWithLoss) {
+  SetLocalMtu(1500);
+  SetRemoteMtu(1500);
+  SetLoss(10);
+  TestTransfer(100000);  // less data so test runs faster
+}
+
+// Test sending data with a 50 ms RTT and 10% packet loss. Transmission should
+// take much longer due to send back-off and slower detection of loss.
+TEST_F(PseudoTcpTest, TestSendWithDelayAndLoss) {
+  SetLocalMtu(1500);
+  SetRemoteMtu(1500);
+  SetDelay(50);
+  SetLoss(10);
+  TestTransfer(100000);  // less data so test runs faster
+}
+
+// Test sending data with 10% packet loss and Nagling disabled.  Transmission
+// should take about the same time as with Nagling enabled.
+TEST_F(PseudoTcpTest, TestSendWithLossAndOptNaglingOff) {
+  SetLocalMtu(1500);
+  SetRemoteMtu(1500);
+  SetLoss(10);
+  SetOptNagling(false);
+  TestTransfer(100000);  // less data so test runs faster
+}
+
+// Test sending data with 10% packet loss and Delayed ACK disabled.
+// Transmission should be slightly faster than with it enabled.
+TEST_F(PseudoTcpTest, TestSendWithLossAndOptAckDelayOff) {
+  SetLocalMtu(1500);
+  SetRemoteMtu(1500);
+  SetLoss(10);
+  SetOptAckDelay(0);
+  TestTransfer(100000);
+}
+
+// Test sending data with 50ms delay and Nagling disabled.
+TEST_F(PseudoTcpTest, TestSendWithDelayAndOptNaglingOff) {
+  SetLocalMtu(1500);
+  SetRemoteMtu(1500);
+  SetDelay(50);
+  SetOptNagling(false);
+  TestTransfer(100000);  // less data so test runs faster
+}
+
+// Test sending data with 50ms delay and Delayed ACK disabled.
+TEST_F(PseudoTcpTest, TestSendWithDelayAndOptAckDelayOff) {
+  SetLocalMtu(1500);
+  SetRemoteMtu(1500);
+  SetDelay(50);
+  SetOptAckDelay(0);
+  TestTransfer(100000);  // less data so test runs faster
+}
+
+// Test a large receive buffer with a sender that doesn't support scaling.
+TEST_F(PseudoTcpTest, TestSendRemoteNoWindowScale) {
+  SetLocalMtu(1500);
+  SetRemoteMtu(1500);
+  SetLocalOptRcvBuf(100000);
+  DisableRemoteWindowScale();
+  TestTransfer(1000000);
+}
+
+// Test a large sender-side receive buffer with a receiver that doesn't support
+// scaling.
+TEST_F(PseudoTcpTest, TestSendLocalNoWindowScale) {
+  SetLocalMtu(1500);
+  SetRemoteMtu(1500);
+  SetRemoteOptRcvBuf(100000);
+  DisableLocalWindowScale();
+  TestTransfer(1000000);
+}
+
+// Test when both sides use window scaling.
+TEST_F(PseudoTcpTest, TestSendBothUseWindowScale) {
+  SetLocalMtu(1500);
+  SetRemoteMtu(1500);
+  SetRemoteOptRcvBuf(100000);
+  SetLocalOptRcvBuf(100000);
+  TestTransfer(1000000);
+}
+
+// Test using a large window scale value.
+TEST_F(PseudoTcpTest, TestSendLargeInFlight) {
+  SetLocalMtu(1500);
+  SetRemoteMtu(1500);
+  SetRemoteOptRcvBuf(100000);
+  SetLocalOptRcvBuf(100000);
+  SetOptSndBuf(150000);
+  TestTransfer(1000000);
+}
+
+TEST_F(PseudoTcpTest, TestSendBothUseLargeWindowScale) {
+  SetLocalMtu(1500);
+  SetRemoteMtu(1500);
+  SetRemoteOptRcvBuf(1000000);
+  SetLocalOptRcvBuf(1000000);
+  TestTransfer(10000000);
+}
+
+// Test using a small receive buffer.
+TEST_F(PseudoTcpTest, TestSendSmallReceiveBuffer) {
+  SetLocalMtu(1500);
+  SetRemoteMtu(1500);
+  SetRemoteOptRcvBuf(10000);
+  SetLocalOptRcvBuf(10000);
+  TestTransfer(1000000);
+}
+
+// Test using a very small receive buffer.
+TEST_F(PseudoTcpTest, TestSendVerySmallReceiveBuffer) {
+  SetLocalMtu(1500);
+  SetRemoteMtu(1500);
+  SetRemoteOptRcvBuf(100);
+  SetLocalOptRcvBuf(100);
+  TestTransfer(100000);
+}
+
+// Ping-pong (request/response) tests
+
+// Test sending <= 1x MTU of data in each ping/pong.  Should take <10ms.
+TEST_F(PseudoTcpTestPingPong, TestPingPong1xMtu) {
+  SetLocalMtu(1500);
+  SetRemoteMtu(1500);
+  TestPingPong(100, 100);
+}
+
+// Test sending 2x-3x MTU of data in each ping/pong.  Should take <10ms.
+TEST_F(PseudoTcpTestPingPong, TestPingPong3xMtu) {
+  SetLocalMtu(1500);
+  SetRemoteMtu(1500);
+  TestPingPong(400, 100);
+}
+
+// Test sending 1x-2x MTU of data in each ping/pong.
+// Should take ~1s, due to interaction between Nagling and Delayed ACK.
+TEST_F(PseudoTcpTestPingPong, TestPingPong2xMtu) {
+  SetLocalMtu(1500);
+  SetRemoteMtu(1500);
+  TestPingPong(2000, 5);
+}
+
+// Test sending 1x-2x MTU of data in each ping/pong with Delayed ACK off.
+// Should take <10ms.
+TEST_F(PseudoTcpTestPingPong, TestPingPong2xMtuWithAckDelayOff) {
+  SetLocalMtu(1500);
+  SetRemoteMtu(1500);
+  SetOptAckDelay(0);
+  TestPingPong(2000, 100);
+}
+
+// Test sending 1x-2x MTU of data in each ping/pong with Nagling off.
+// Should take <10ms.
+TEST_F(PseudoTcpTestPingPong, TestPingPong2xMtuWithNaglingOff) {
+  SetLocalMtu(1500);
+  SetRemoteMtu(1500);
+  SetOptNagling(false);
+  TestPingPong(2000, 5);
+}
+
+// Test sending a ping as pair of short (non-full) segments.
+// Should take ~1s, due to Delayed ACK interaction with Nagling.
+TEST_F(PseudoTcpTestPingPong, TestPingPongShortSegments) {
+  SetLocalMtu(1500);
+  SetRemoteMtu(1500);
+  SetOptAckDelay(5000);
+  SetBytesPerSend(50); // i.e. two Send calls per payload
+  TestPingPong(100, 5);
+}
+
+// Test sending ping as a pair of short (non-full) segments, with Nagling off.
+// Should take <10ms.
+TEST_F(PseudoTcpTestPingPong, TestPingPongShortSegmentsWithNaglingOff) {
+  SetLocalMtu(1500);
+  SetRemoteMtu(1500);
+  SetOptNagling(false);
+  SetBytesPerSend(50); // i.e. two Send calls per payload
+  TestPingPong(100, 5);
+}
+
+// Test sending <= 1x MTU of data ping/pong, in two segments, no Delayed ACK.
+// Should take ~1s.
+TEST_F(PseudoTcpTestPingPong, TestPingPongShortSegmentsWithAckDelayOff) {
+  SetLocalMtu(1500);
+  SetRemoteMtu(1500);
+  SetBytesPerSend(50); // i.e. two Send calls per payload
+  SetOptAckDelay(0);
+  TestPingPong(100, 5);
+}
+
+// Test that receive window expands and contract correctly.
+TEST_F(PseudoTcpTestReceiveWindow, TestReceiveWindow) {
+  SetLocalMtu(1500);
+  SetRemoteMtu(1500);
+  SetOptNagling(false);
+  SetOptAckDelay(0);
+  TestTransfer(1024 * 1000);
+}
+
+// Test setting send window size to a very small value.
+TEST_F(PseudoTcpTestReceiveWindow, TestSetVerySmallSendWindowSize) {
+  SetLocalMtu(1500);
+  SetRemoteMtu(1500);
+  SetOptNagling(false);
+  SetOptAckDelay(0);
+  SetOptSndBuf(900);
+  TestTransfer(1024 * 1000);
+  EXPECT_EQ(900u, EstimateSendWindowSize());
+}
+
+// Test setting receive window size to a value other than default.
+TEST_F(PseudoTcpTestReceiveWindow, TestSetReceiveWindowSize) {
+  SetLocalMtu(1500);
+  SetRemoteMtu(1500);
+  SetOptNagling(false);
+  SetOptAckDelay(0);
+  SetRemoteOptRcvBuf(100000);
+  SetLocalOptRcvBuf(100000);
+  TestTransfer(1024 * 1000);
+  EXPECT_EQ(100000u, EstimateReceiveWindowSize());
+}
+
+/* Test sending data with mismatched MTUs. We should detect this and reduce
+// our packet size accordingly.
+// TODO: This doesn't actually work right now. The current code
+// doesn't detect if the MTU is set too high on either side.
+TEST_F(PseudoTcpTest, TestSendWithMismatchedMtus) {
+  SetLocalMtu(1500);
+  SetRemoteMtu(1280);
+  TestTransfer(1000000);
+}
+*/
diff --git a/webrtc/p2p/base/rawtransport.cc b/webrtc/p2p/base/rawtransport.cc
new file mode 100644
index 0000000..374ed98
--- /dev/null
+++ b/webrtc/p2p/base/rawtransport.cc
@@ -0,0 +1,115 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <string>
+#include <vector>
+#include "webrtc/p2p/base/constants.h"
+#include "webrtc/p2p/base/parsing.h"
+#include "webrtc/p2p/base/rawtransport.h"
+#include "webrtc/p2p/base/rawtransportchannel.h"
+#include "webrtc/p2p/base/sessionmanager.h"
+#include "webrtc/libjingle/xmllite/qname.h"
+#include "webrtc/libjingle/xmllite/xmlelement.h"
+#include "webrtc/libjingle/xmpp/constants.h"
+#include "webrtc/base/common.h"
+
+#if defined(FEATURE_ENABLE_PSTN)
+namespace cricket {
+
+RawTransport::RawTransport(rtc::Thread* signaling_thread,
+                           rtc::Thread* worker_thread,
+                           const std::string& content_name,
+                           PortAllocator* allocator)
+    : Transport(signaling_thread, worker_thread,
+                content_name, NS_GINGLE_RAW, allocator) {
+}
+
+RawTransport::~RawTransport() {
+  DestroyAllChannels();
+}
+
+bool RawTransport::ParseCandidates(SignalingProtocol protocol,
+                                   const buzz::XmlElement* elem,
+                                   const CandidateTranslator* translator,
+                                   Candidates* candidates,
+                                   ParseError* error) {
+  for (const buzz::XmlElement* cand_elem = elem->FirstElement();
+       cand_elem != NULL;
+       cand_elem = cand_elem->NextElement()) {
+    if (cand_elem->Name() == QN_GINGLE_RAW_CHANNEL) {
+      if (!cand_elem->HasAttr(buzz::QN_NAME)) {
+        return BadParse("no channel name given", error);
+      }
+      if (type() != cand_elem->Attr(buzz::QN_NAME)) {
+        return BadParse("channel named does not exist", error);
+      }
+      rtc::SocketAddress addr;
+      if (!ParseRawAddress(cand_elem, &addr, error))
+        return false;
+
+      Candidate candidate;
+      candidate.set_component(1);
+      candidate.set_address(addr);
+      candidates->push_back(candidate);
+    }
+  }
+  return true;
+}
+
+bool RawTransport::WriteCandidates(SignalingProtocol protocol,
+                                   const Candidates& candidates,
+                                   const CandidateTranslator* translator,
+                                   XmlElements* candidate_elems,
+                                   WriteError* error) {
+  for (std::vector<Candidate>::const_iterator
+       cand = candidates.begin();
+       cand != candidates.end();
+       ++cand) {
+    ASSERT(cand->component() == 1);
+    ASSERT(cand->protocol() == "udp");
+    rtc::SocketAddress addr = cand->address();
+
+    buzz::XmlElement* elem = new buzz::XmlElement(QN_GINGLE_RAW_CHANNEL);
+    elem->SetAttr(buzz::QN_NAME, type());
+    elem->SetAttr(QN_ADDRESS, addr.ipaddr().ToString());
+    elem->SetAttr(QN_PORT, addr.PortAsString());
+    candidate_elems->push_back(elem);
+  }
+  return true;
+}
+
+bool RawTransport::ParseRawAddress(const buzz::XmlElement* elem,
+                                   rtc::SocketAddress* addr,
+                                   ParseError* error) {
+  // Make sure the required attributes exist
+  if (!elem->HasAttr(QN_ADDRESS) ||
+      !elem->HasAttr(QN_PORT)) {
+    return BadParse("channel missing required attribute", error);
+  }
+
+  // Parse the address.
+  if (!ParseAddress(elem, QN_ADDRESS, QN_PORT, addr, error))
+    return false;
+
+  return true;
+}
+
+TransportChannelImpl* RawTransport::CreateTransportChannel(int component) {
+  return new RawTransportChannel(content_name(), component, this,
+                                 worker_thread(),
+                                 port_allocator());
+}
+
+void RawTransport::DestroyTransportChannel(TransportChannelImpl* channel) {
+  delete channel;
+}
+
+}  // namespace cricket
+#endif  // defined(FEATURE_ENABLE_PSTN)
diff --git a/webrtc/p2p/base/rawtransport.h b/webrtc/p2p/base/rawtransport.h
new file mode 100644
index 0000000..dbe8f98
--- /dev/null
+++ b/webrtc/p2p/base/rawtransport.h
@@ -0,0 +1,64 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_RAWTRANSPORT_H_
+#define WEBRTC_P2P_BASE_RAWTRANSPORT_H_
+
+#include <string>
+#include "webrtc/p2p/base/transport.h"
+
+#if defined(FEATURE_ENABLE_PSTN)
+namespace cricket {
+
+// Implements a transport that only sends raw packets, no STUN.  As a result,
+// it cannot do pings to determine connectivity, so it only uses a single port
+// that it thinks will work.
+class RawTransport : public Transport, public TransportParser {
+ public:
+  RawTransport(rtc::Thread* signaling_thread,
+               rtc::Thread* worker_thread,
+               const std::string& content_name,
+               PortAllocator* allocator);
+  virtual ~RawTransport();
+
+  virtual bool ParseCandidates(SignalingProtocol protocol,
+                               const buzz::XmlElement* elem,
+                               const CandidateTranslator* translator,
+                               Candidates* candidates,
+                               ParseError* error);
+  virtual bool WriteCandidates(SignalingProtocol protocol,
+                               const Candidates& candidates,
+                               const CandidateTranslator* translator,
+                               XmlElements* candidate_elems,
+                               WriteError* error);
+
+ protected:
+  // Creates and destroys raw channels.
+  virtual TransportChannelImpl* CreateTransportChannel(int component);
+  virtual void DestroyTransportChannel(TransportChannelImpl* channel);
+
+ private:
+  // Parses the given element, which should describe the address to use for a
+  // given channel.  This will return false and signal an error if the address
+  // or channel name is bad.
+  bool ParseRawAddress(const buzz::XmlElement* elem,
+                       rtc::SocketAddress* addr,
+                       ParseError* error);
+
+  friend class RawTransportChannel;  // For ParseAddress.
+
+  DISALLOW_EVIL_CONSTRUCTORS(RawTransport);
+};
+
+}  // namespace cricket
+
+#endif  // defined(FEATURE_ENABLE_PSTN)
+
+#endif  // WEBRTC_P2P_BASE_RAWTRANSPORT_H_
diff --git a/webrtc/p2p/base/rawtransportchannel.cc b/webrtc/p2p/base/rawtransportchannel.cc
new file mode 100644
index 0000000..5779c6e
--- /dev/null
+++ b/webrtc/p2p/base/rawtransportchannel.cc
@@ -0,0 +1,260 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/rawtransportchannel.h"
+
+#include <string>
+#include <vector>
+#include "webrtc/p2p/base/constants.h"
+#include "webrtc/p2p/base/portallocator.h"
+#include "webrtc/p2p/base/portinterface.h"
+#include "webrtc/p2p/base/rawtransport.h"
+#include "webrtc/p2p/base/relayport.h"
+#include "webrtc/p2p/base/sessionmanager.h"
+#include "webrtc/p2p/base/stunport.h"
+#include "webrtc/libjingle/xmllite/qname.h"
+#include "webrtc/libjingle/xmllite/xmlelement.h"
+#include "webrtc/libjingle/xmpp/constants.h"
+#include "webrtc/base/common.h"
+
+#if defined(FEATURE_ENABLE_PSTN)
+
+namespace {
+
+const uint32 MSG_DESTROY_RTC_UNUSED_PORTS = 1;
+
+}  // namespace
+
+namespace cricket {
+
+RawTransportChannel::RawTransportChannel(const std::string& content_name,
+                                         int component,
+                                         RawTransport* transport,
+                                         rtc::Thread *worker_thread,
+                                         PortAllocator *allocator)
+  : TransportChannelImpl(content_name, component),
+    raw_transport_(transport),
+    allocator_(allocator),
+    allocator_session_(NULL),
+    stun_port_(NULL),
+    relay_port_(NULL),
+    port_(NULL),
+    use_relay_(false) {
+  if (worker_thread == NULL)
+    worker_thread_ = raw_transport_->worker_thread();
+  else
+    worker_thread_ = worker_thread;
+}
+
+RawTransportChannel::~RawTransportChannel() {
+  delete allocator_session_;
+}
+
+int RawTransportChannel::SendPacket(const char *data, size_t size,
+                                    const rtc::PacketOptions& options,
+                                    int flags) {
+  if (port_ == NULL)
+    return -1;
+  if (remote_address_.IsNil())
+    return -1;
+  if (flags != 0)
+    return -1;
+  return port_->SendTo(data, size, remote_address_, options, true);
+}
+
+int RawTransportChannel::SetOption(rtc::Socket::Option opt, int value) {
+  // TODO: allow these to be set before we have a port
+  if (port_ == NULL)
+    return -1;
+  return port_->SetOption(opt, value);
+}
+
+int RawTransportChannel::GetError() {
+  return (port_ != NULL) ? port_->GetError() : 0;
+}
+
+void RawTransportChannel::Connect() {
+  // Create an allocator that only returns stun and relay ports.
+  // Use empty string for ufrag and pwd here. There won't be any STUN or relay
+  // interactions when using RawTC.
+  // TODO: Change raw to only use local udp ports.
+  allocator_session_ = allocator_->CreateSession(
+      SessionId(), content_name(), component(), "", "");
+
+  uint32 flags = PORTALLOCATOR_DISABLE_UDP | PORTALLOCATOR_DISABLE_TCP;
+
+#if !defined(FEATURE_ENABLE_STUN_CLASSIFICATION)
+  flags |= PORTALLOCATOR_DISABLE_RELAY;
+#endif
+  allocator_session_->set_flags(flags);
+  allocator_session_->SignalPortReady.connect(
+      this, &RawTransportChannel::OnPortReady);
+  allocator_session_->SignalCandidatesReady.connect(
+      this, &RawTransportChannel::OnCandidatesReady);
+
+  // The initial ports will include stun.
+  allocator_session_->StartGettingPorts();
+}
+
+void RawTransportChannel::Reset() {
+  set_readable(false);
+  set_writable(false);
+
+  delete allocator_session_;
+
+  allocator_session_ = NULL;
+  stun_port_ = NULL;
+  relay_port_ = NULL;
+  port_ = NULL;
+  remote_address_ = rtc::SocketAddress();
+}
+
+void RawTransportChannel::OnCandidate(const Candidate& candidate) {
+  remote_address_ = candidate.address();
+  ASSERT(!remote_address_.IsNil());
+  set_readable(true);
+
+  // We can write once we have a port and a remote address.
+  if (port_ != NULL)
+    SetWritable();
+}
+
+void RawTransportChannel::OnRemoteAddress(
+    const rtc::SocketAddress& remote_address) {
+  remote_address_ = remote_address;
+  set_readable(true);
+
+  if (port_ != NULL)
+    SetWritable();
+}
+
+// Note about stun classification
+// Code to classify our NAT type and use the relay port if we are behind an
+// asymmetric NAT is under a FEATURE_ENABLE_STUN_CLASSIFICATION #define.
+// To turn this one we will have to enable a second stun address and make sure
+// that the relay server works for raw UDP.
+//
+// Another option is to classify the NAT type early and not offer the raw
+// transport type at all if we can't support it.
+
+void RawTransportChannel::OnPortReady(
+    PortAllocatorSession* session, PortInterface* port) {
+  ASSERT(session == allocator_session_);
+
+  if (port->Type() == STUN_PORT_TYPE) {
+    stun_port_ = static_cast<StunPort*>(port);
+  } else if (port->Type() == RELAY_PORT_TYPE) {
+    relay_port_ = static_cast<RelayPort*>(port);
+  } else {
+    ASSERT(false);
+  }
+}
+
+void RawTransportChannel::OnCandidatesReady(
+    PortAllocatorSession *session, const std::vector<Candidate>& candidates) {
+  ASSERT(session == allocator_session_);
+  ASSERT(candidates.size() >= 1);
+
+  // The most recent candidate is the one we haven't seen yet.
+  Candidate c = candidates[candidates.size() - 1];
+
+  if (c.type() == STUN_PORT_TYPE) {
+    ASSERT(stun_port_ != NULL);
+
+#if defined(FEATURE_ENABLE_STUN_CLASSIFICATION)
+    // We need to wait until we have two addresses.
+    if (stun_port_->candidates().size() < 2)
+      return;
+
+    // This is the second address.  If these addresses are the same, then we
+    // are not behind a symmetric NAT.  Hence, a stun port should be sufficient.
+    if (stun_port_->candidates()[0].address() ==
+        stun_port_->candidates()[1].address()) {
+      SetPort(stun_port_);
+      return;
+    }
+
+    // We will need to use relay.
+    use_relay_ = true;
+
+    // If we already have a relay address, we're good.  Otherwise, we will need
+    // to wait until one arrives.
+    if (relay_port_->candidates().size() > 0)
+      SetPort(relay_port_);
+#else  // defined(FEATURE_ENABLE_STUN_CLASSIFICATION)
+    // Always use the stun port.  We don't classify right now so just assume it
+    // will work fine.
+    SetPort(stun_port_);
+#endif
+  } else if (c.type() == RELAY_PORT_TYPE) {
+    if (use_relay_)
+      SetPort(relay_port_);
+  } else {
+    ASSERT(false);
+  }
+}
+
+void RawTransportChannel::SetPort(PortInterface* port) {
+  ASSERT(port_ == NULL);
+  port_ = port;
+
+  // We don't need any ports other than the one we picked.
+  allocator_session_->StopGettingPorts();
+  worker_thread_->Post(
+      this, MSG_DESTROY_RTC_UNUSED_PORTS, NULL);
+
+  // Send a message to the other client containing our address.
+
+  ASSERT(port_->Candidates().size() >= 1);
+  ASSERT(port_->Candidates()[0].protocol() == "udp");
+  SignalCandidateReady(this, port_->Candidates()[0]);
+
+  // Read all packets from this port.
+  port_->EnablePortPackets();
+  port_->SignalReadPacket.connect(this, &RawTransportChannel::OnReadPacket);
+
+  // We can write once we have a port and a remote address.
+  if (!remote_address_.IsAny())
+    SetWritable();
+}
+
+void RawTransportChannel::SetWritable() {
+  ASSERT(port_ != NULL);
+  ASSERT(!remote_address_.IsAny());
+
+  set_writable(true);
+
+  Candidate remote_candidate;
+  remote_candidate.set_address(remote_address_);
+  SignalRouteChange(this, remote_candidate);
+}
+
+void RawTransportChannel::OnReadPacket(
+    PortInterface* port, const char* data, size_t size,
+    const rtc::SocketAddress& addr) {
+  ASSERT(port_ == port);
+  SignalReadPacket(this, data, size, rtc::CreatePacketTime(0), 0);
+}
+
+void RawTransportChannel::OnMessage(rtc::Message* msg) {
+  ASSERT(msg->message_id == MSG_DESTROY_RTC_UNUSED_PORTS);
+  ASSERT(port_ != NULL);
+  if (port_ != stun_port_) {
+    stun_port_->Destroy();
+    stun_port_ = NULL;
+  }
+  if (port_ != relay_port_ && relay_port_ != NULL) {
+    relay_port_->Destroy();
+    relay_port_ = NULL;
+  }
+}
+
+}  // namespace cricket
+#endif  // defined(FEATURE_ENABLE_PSTN)
diff --git a/webrtc/p2p/base/rawtransportchannel.h b/webrtc/p2p/base/rawtransportchannel.h
new file mode 100644
index 0000000..3041cad
--- /dev/null
+++ b/webrtc/p2p/base/rawtransportchannel.h
@@ -0,0 +1,189 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_RAWTRANSPORTCHANNEL_H_
+#define WEBRTC_P2P_BASE_RAWTRANSPORTCHANNEL_H_
+
+#include <string>
+#include <vector>
+#include "webrtc/p2p/base/candidate.h"
+#include "webrtc/p2p/base/rawtransport.h"
+#include "webrtc/p2p/base/transportchannelimpl.h"
+#include "webrtc/base/messagequeue.h"
+
+#if defined(FEATURE_ENABLE_PSTN)
+
+namespace rtc {
+class Thread;
+}
+
+namespace cricket {
+
+class Connection;
+class PortAllocator;
+class PortAllocatorSession;
+class PortInterface;
+class RelayPort;
+class StunPort;
+
+// Implements a channel that just sends bare packets once we have received the
+// address of the other side.  We pick a single address to send them based on
+// a simple investigation of NAT type.
+class RawTransportChannel : public TransportChannelImpl,
+    public rtc::MessageHandler {
+ public:
+  RawTransportChannel(const std::string& content_name,
+                      int component,
+                      RawTransport* transport,
+                      rtc::Thread *worker_thread,
+                      PortAllocator *allocator);
+  virtual ~RawTransportChannel();
+
+  // Implementation of normal channel packet sending.
+  virtual int SendPacket(const char *data, size_t len,
+                         const rtc::PacketOptions& options, int flags);
+  virtual int SetOption(rtc::Socket::Option opt, int value);
+  virtual int GetError();
+
+  // Implements TransportChannelImpl.
+  virtual Transport* GetTransport() { return raw_transport_; }
+  virtual void SetIceCredentials(const std::string& ice_ufrag,
+                                 const std::string& ice_pwd) {}
+  virtual void SetRemoteIceCredentials(const std::string& ice_ufrag,
+                                       const std::string& ice_pwd) {}
+
+  // Creates an allocator session to start figuring out which type of
+  // port we should send to the other client.  This will send
+  // SignalAvailableCandidate once we have decided.
+  virtual void Connect();
+
+  // Resets state back to unconnected.
+  virtual void Reset();
+
+  // We don't actually worry about signaling since we can't send new candidates.
+  virtual void OnSignalingReady() {}
+
+  // Handles a message setting the remote address.  We are writable once we
+  // have this since we now know where to send.
+  virtual void OnCandidate(const Candidate& candidate);
+
+  void OnRemoteAddress(const rtc::SocketAddress& remote_address);
+
+  // Below ICE specific virtual methods not implemented.
+  virtual IceRole GetIceRole() const { return ICEROLE_UNKNOWN; }
+  virtual void SetIceRole(IceRole role) {}
+  virtual void SetIceTiebreaker(uint64 tiebreaker) {}
+
+  virtual bool GetIceProtocolType(IceProtocolType* type) const { return false; }
+  virtual void SetIceProtocolType(IceProtocolType type) {}
+
+  virtual void SetIceUfrag(const std::string& ice_ufrag) {}
+  virtual void SetIcePwd(const std::string& ice_pwd) {}
+  virtual void SetRemoteIceMode(IceMode mode) {}
+  virtual size_t GetConnectionCount() const { return 1; }
+
+  virtual bool GetStats(ConnectionInfos* infos) {
+    return false;
+  }
+
+  // DTLS methods.
+  virtual bool IsDtlsActive() const { return false; }
+
+  // Default implementation.
+  virtual bool GetSslRole(rtc::SSLRole* role) const {
+    return false;
+  }
+
+  virtual bool SetSslRole(rtc::SSLRole role) {
+    return false;
+  }
+
+  // Set up the ciphers to use for DTLS-SRTP.
+  virtual bool SetSrtpCiphers(const std::vector<std::string>& ciphers) {
+    return false;
+  }
+
+  // Find out which DTLS-SRTP cipher was negotiated
+  virtual bool GetSrtpCipher(std::string* cipher) {
+    return false;
+  }
+
+  // Returns false because the channel is not DTLS.
+  virtual bool GetLocalIdentity(rtc::SSLIdentity** identity) const {
+    return false;
+  }
+
+  virtual bool GetRemoteCertificate(rtc::SSLCertificate** cert) const {
+    return false;
+  }
+
+  // Allows key material to be extracted for external encryption.
+  virtual bool ExportKeyingMaterial(
+      const std::string& label,
+      const uint8* context,
+      size_t context_len,
+      bool use_context,
+      uint8* result,
+      size_t result_len) {
+    return false;
+  }
+
+  virtual bool SetLocalIdentity(rtc::SSLIdentity* identity) {
+    return false;
+  }
+
+  // Set DTLS Remote fingerprint. Must be after local identity set.
+  virtual bool SetRemoteFingerprint(
+    const std::string& digest_alg,
+    const uint8* digest,
+    size_t digest_len) {
+    return false;
+  }
+
+ private:
+  RawTransport* raw_transport_;
+  rtc::Thread *worker_thread_;
+  PortAllocator* allocator_;
+  PortAllocatorSession* allocator_session_;
+  StunPort* stun_port_;
+  RelayPort* relay_port_;
+  PortInterface* port_;
+  bool use_relay_;
+  rtc::SocketAddress remote_address_;
+
+  // Called when the allocator creates another port.
+  void OnPortReady(PortAllocatorSession* session, PortInterface* port);
+
+  // Called when one of the ports we are using has determined its address.
+  void OnCandidatesReady(PortAllocatorSession *session,
+                         const std::vector<Candidate>& candidates);
+
+  // Called once we have chosen the port to use for communication with the
+  // other client.  This will send its address and prepare the port for use.
+  void SetPort(PortInterface* port);
+
+  // Called once we have a port and a remote address.  This will set mark the
+  // channel as writable and signal the route to the client.
+  void SetWritable();
+
+  // Called when we receive a packet from the other client.
+  void OnReadPacket(PortInterface* port, const char* data, size_t size,
+                    const rtc::SocketAddress& addr);
+
+  // Handles a message to destroy unused ports.
+  virtual void OnMessage(rtc::Message *msg);
+
+  DISALLOW_EVIL_CONSTRUCTORS(RawTransportChannel);
+};
+
+}  // namespace cricket
+
+#endif  // defined(FEATURE_ENABLE_PSTN)
+#endif  // WEBRTC_P2P_BASE_RAWTRANSPORTCHANNEL_H_
diff --git a/webrtc/p2p/base/relayport.cc b/webrtc/p2p/base/relayport.cc
new file mode 100644
index 0000000..4c40b3d
--- /dev/null
+++ b/webrtc/p2p/base/relayport.cc
@@ -0,0 +1,818 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/relayport.h"
+#include "webrtc/base/asyncpacketsocket.h"
+#include "webrtc/base/helpers.h"
+#include "webrtc/base/logging.h"
+
+namespace cricket {
+
+static const uint32 kMessageConnectTimeout = 1;
+static const int kKeepAliveDelay           = 10 * 60 * 1000;
+static const int kRetryTimeout             = 50 * 1000;  // ICE says 50 secs
+// How long to wait for a socket to connect to remote host in milliseconds
+// before trying another connection.
+static const int kSoftConnectTimeoutMs     = 3 * 1000;
+
+// Handles a connection to one address/port/protocol combination for a
+// particular RelayEntry.
+class RelayConnection : public sigslot::has_slots<> {
+ public:
+  RelayConnection(const ProtocolAddress* protocol_address,
+                  rtc::AsyncPacketSocket* socket,
+                  rtc::Thread* thread);
+  ~RelayConnection();
+  rtc::AsyncPacketSocket* socket() const { return socket_; }
+
+  const ProtocolAddress* protocol_address() {
+    return protocol_address_;
+  }
+
+  rtc::SocketAddress GetAddress() const {
+    return protocol_address_->address;
+  }
+
+  ProtocolType GetProtocol() const {
+    return protocol_address_->proto;
+  }
+
+  int SetSocketOption(rtc::Socket::Option opt, int value);
+
+  // Validates a response to a STUN allocate request.
+  bool CheckResponse(StunMessage* msg);
+
+  // Sends data to the relay server.
+  int Send(const void* pv, size_t cb, const rtc::PacketOptions& options);
+
+  // Sends a STUN allocate request message to the relay server.
+  void SendAllocateRequest(RelayEntry* entry, int delay);
+
+  // Return the latest error generated by the socket.
+  int GetError() { return socket_->GetError(); }
+
+  // Called on behalf of a StunRequest to write data to the socket.  This is
+  // already STUN intended for the server, so no wrapping is necessary.
+  void OnSendPacket(const void* data, size_t size, StunRequest* req);
+
+ private:
+  rtc::AsyncPacketSocket* socket_;
+  const ProtocolAddress* protocol_address_;
+  StunRequestManager *request_manager_;
+};
+
+// Manages a number of connections to the relayserver, one for each
+// available protocol. We aim to use each connection for only a
+// specific destination address so that we can avoid wrapping every
+// packet in a STUN send / data indication.
+class RelayEntry : public rtc::MessageHandler,
+                   public sigslot::has_slots<> {
+ public:
+  RelayEntry(RelayPort* port, const rtc::SocketAddress& ext_addr);
+  ~RelayEntry();
+
+  RelayPort* port() { return port_; }
+
+  const rtc::SocketAddress& address() const { return ext_addr_; }
+  void set_address(const rtc::SocketAddress& addr) { ext_addr_ = addr; }
+
+  bool connected() const { return connected_; }
+  bool locked() const { return locked_; }
+
+  // Returns the last error on the socket of this entry.
+  int GetError();
+
+  // Returns the most preferred connection of the given
+  // ones. Connections are rated based on protocol in the order of:
+  // UDP, TCP and SSLTCP, where UDP is the most preferred protocol
+  static RelayConnection* GetBestConnection(RelayConnection* conn1,
+                                            RelayConnection* conn2);
+
+  // Sends the STUN requests to the server to initiate this connection.
+  void Connect();
+
+  // Called when this entry becomes connected.  The address given is the one
+  // exposed to the outside world on the relay server.
+  void OnConnect(const rtc::SocketAddress& mapped_addr,
+                 RelayConnection* socket);
+
+  // Sends a packet to the given destination address using the socket of this
+  // entry.  This will wrap the packet in STUN if necessary.
+  int SendTo(const void* data, size_t size,
+             const rtc::SocketAddress& addr,
+             const rtc::PacketOptions& options);
+
+  // Schedules a keep-alive allocate request.
+  void ScheduleKeepAlive();
+
+  void SetServerIndex(size_t sindex) { server_index_ = sindex; }
+
+  // Sets this option on the socket of each connection.
+  int SetSocketOption(rtc::Socket::Option opt, int value);
+
+  size_t ServerIndex() const { return server_index_; }
+
+  // Try a different server address
+  void HandleConnectFailure(rtc::AsyncPacketSocket* socket);
+
+  // Implementation of the MessageHandler Interface.
+  virtual void OnMessage(rtc::Message *pmsg);
+
+ private:
+  RelayPort* port_;
+  rtc::SocketAddress ext_addr_;
+  size_t server_index_;
+  bool connected_;
+  bool locked_;
+  RelayConnection* current_connection_;
+
+  // Called when a TCP connection is established or fails
+  void OnSocketConnect(rtc::AsyncPacketSocket* socket);
+  void OnSocketClose(rtc::AsyncPacketSocket* socket, int error);
+
+  // Called when a packet is received on this socket.
+  void OnReadPacket(
+    rtc::AsyncPacketSocket* socket,
+    const char* data, size_t size,
+    const rtc::SocketAddress& remote_addr,
+    const rtc::PacketTime& packet_time);
+  // Called when the socket is currently able to send.
+  void OnReadyToSend(rtc::AsyncPacketSocket* socket);
+
+  // Sends the given data on the socket to the server with no wrapping.  This
+  // returns the number of bytes written or -1 if an error occurred.
+  int SendPacket(const void* data, size_t size,
+                 const rtc::PacketOptions& options);
+};
+
+// Handles an allocate request for a particular RelayEntry.
+class AllocateRequest : public StunRequest {
+ public:
+  AllocateRequest(RelayEntry* entry, RelayConnection* connection);
+  virtual ~AllocateRequest() {}
+
+  virtual void Prepare(StunMessage* request);
+
+  virtual int GetNextDelay();
+
+  virtual void OnResponse(StunMessage* response);
+  virtual void OnErrorResponse(StunMessage* response);
+  virtual void OnTimeout();
+
+ private:
+  RelayEntry* entry_;
+  RelayConnection* connection_;
+  uint32 start_time_;
+};
+
+RelayPort::RelayPort(
+    rtc::Thread* thread, rtc::PacketSocketFactory* factory,
+    rtc::Network* network, const rtc::IPAddress& ip,
+    int min_port, int max_port, const std::string& username,
+    const std::string& password)
+    : Port(thread, RELAY_PORT_TYPE, factory, network, ip, min_port, max_port,
+           username, password),
+      ready_(false),
+      error_(0) {
+  entries_.push_back(
+      new RelayEntry(this, rtc::SocketAddress()));
+  // TODO: set local preference value for TCP based candidates.
+}
+
+RelayPort::~RelayPort() {
+  for (size_t i = 0; i < entries_.size(); ++i)
+    delete entries_[i];
+  thread()->Clear(this);
+}
+
+void RelayPort::AddServerAddress(const ProtocolAddress& addr) {
+  // Since HTTP proxies usually only allow 443,
+  // let's up the priority on PROTO_SSLTCP
+  if (addr.proto == PROTO_SSLTCP &&
+      (proxy().type == rtc::PROXY_HTTPS ||
+       proxy().type == rtc::PROXY_UNKNOWN)) {
+    server_addr_.push_front(addr);
+  } else {
+    server_addr_.push_back(addr);
+  }
+}
+
+void RelayPort::AddExternalAddress(const ProtocolAddress& addr) {
+  std::string proto_name = ProtoToString(addr.proto);
+  for (std::vector<ProtocolAddress>::iterator it = external_addr_.begin();
+       it != external_addr_.end(); ++it) {
+    if ((it->address == addr.address) && (it->proto == addr.proto)) {
+      LOG(INFO) << "Redundant relay address: " << proto_name
+                << " @ " << addr.address.ToSensitiveString();
+      return;
+    }
+  }
+  external_addr_.push_back(addr);
+}
+
+void RelayPort::SetReady() {
+  if (!ready_) {
+    std::vector<ProtocolAddress>::iterator iter;
+    for (iter = external_addr_.begin();
+         iter != external_addr_.end(); ++iter) {
+      std::string proto_name = ProtoToString(iter->proto);
+      // In case of Gturn, related address is set to null socket address.
+      // This is due to as mapped address stun attribute is used for allocated
+      // address.
+      AddAddress(iter->address, iter->address, rtc::SocketAddress(),
+                 proto_name, "", RELAY_PORT_TYPE,
+                 ICE_TYPE_PREFERENCE_RELAY, 0, false);
+    }
+    ready_ = true;
+    SignalPortComplete(this);
+  }
+}
+
+const ProtocolAddress * RelayPort::ServerAddress(size_t index) const {
+  if (index < server_addr_.size())
+    return &server_addr_[index];
+  return NULL;
+}
+
+bool RelayPort::HasMagicCookie(const char* data, size_t size) {
+  if (size < 24 + sizeof(TURN_MAGIC_COOKIE_VALUE)) {
+    return false;
+  } else {
+    return memcmp(data + 24,
+                  TURN_MAGIC_COOKIE_VALUE,
+                  sizeof(TURN_MAGIC_COOKIE_VALUE)) == 0;
+  }
+}
+
+void RelayPort::PrepareAddress() {
+  // We initiate a connect on the first entry.  If this completes, it will fill
+  // in the server address as the address of this port.
+  ASSERT(entries_.size() == 1);
+  entries_[0]->Connect();
+  ready_ = false;
+}
+
+Connection* RelayPort::CreateConnection(const Candidate& address,
+                                        CandidateOrigin origin) {
+  // We only create conns to non-udp sockets if they are incoming on this port
+  if ((address.protocol() != UDP_PROTOCOL_NAME) &&
+      (origin != ORIGIN_THIS_PORT)) {
+    return 0;
+  }
+
+  // We don't support loopback on relays
+  if (address.type() == Type()) {
+    return 0;
+  }
+
+  if (!IsCompatibleAddress(address.address())) {
+    return 0;
+  }
+
+  size_t index = 0;
+  for (size_t i = 0; i < Candidates().size(); ++i) {
+    const Candidate& local = Candidates()[i];
+    if (local.protocol() == address.protocol()) {
+      index = i;
+      break;
+    }
+  }
+
+  Connection * conn = new ProxyConnection(this, index, address);
+  AddConnection(conn);
+  return conn;
+}
+
+int RelayPort::SendTo(const void* data, size_t size,
+                      const rtc::SocketAddress& addr,
+                      const rtc::PacketOptions& options,
+                      bool payload) {
+  // Try to find an entry for this specific address.  Note that the first entry
+  // created was not given an address initially, so it can be set to the first
+  // address that comes along.
+  RelayEntry* entry = 0;
+
+  for (size_t i = 0; i < entries_.size(); ++i) {
+    if (entries_[i]->address().IsNil() && payload) {
+      entry = entries_[i];
+      entry->set_address(addr);
+      break;
+    } else if (entries_[i]->address() == addr) {
+      entry = entries_[i];
+      break;
+    }
+  }
+
+  // If we did not find one, then we make a new one.  This will not be useable
+  // until it becomes connected, however.
+  if (!entry && payload) {
+    entry = new RelayEntry(this, addr);
+    if (!entries_.empty()) {
+      entry->SetServerIndex(entries_[0]->ServerIndex());
+    }
+    entry->Connect();
+    entries_.push_back(entry);
+  }
+
+  // If the entry is connected, then we can send on it (though wrapping may
+  // still be necessary).  Otherwise, we can't yet use this connection, so we
+  // default to the first one.
+  if (!entry || !entry->connected()) {
+    ASSERT(!entries_.empty());
+    entry = entries_[0];
+    if (!entry->connected()) {
+      error_ = EWOULDBLOCK;
+      return SOCKET_ERROR;
+    }
+  }
+
+  // Send the actual contents to the server using the usual mechanism.
+  int sent = entry->SendTo(data, size, addr, options);
+  if (sent <= 0) {
+    ASSERT(sent < 0);
+    error_ = entry->GetError();
+    return SOCKET_ERROR;
+  }
+  // The caller of the function is expecting the number of user data bytes,
+  // rather than the size of the packet.
+  return static_cast<int>(size);
+}
+
+int RelayPort::SetOption(rtc::Socket::Option opt, int value) {
+  int result = 0;
+  for (size_t i = 0; i < entries_.size(); ++i) {
+    if (entries_[i]->SetSocketOption(opt, value) < 0) {
+      result = -1;
+      error_ = entries_[i]->GetError();
+    }
+  }
+  options_.push_back(OptionValue(opt, value));
+  return result;
+}
+
+int RelayPort::GetOption(rtc::Socket::Option opt, int* value) {
+  std::vector<OptionValue>::iterator it;
+  for (it = options_.begin(); it < options_.end(); ++it) {
+    if (it->first == opt) {
+      *value = it->second;
+      return 0;
+    }
+  }
+  return SOCKET_ERROR;
+}
+
+int RelayPort::GetError() {
+  return error_;
+}
+
+void RelayPort::OnReadPacket(
+    const char* data, size_t size,
+    const rtc::SocketAddress& remote_addr,
+    ProtocolType proto,
+    const rtc::PacketTime& packet_time) {
+  if (Connection* conn = GetConnection(remote_addr)) {
+    conn->OnReadPacket(data, size, packet_time);
+  } else {
+    Port::OnReadPacket(data, size, remote_addr, proto);
+  }
+}
+
+RelayConnection::RelayConnection(const ProtocolAddress* protocol_address,
+                                 rtc::AsyncPacketSocket* socket,
+                                 rtc::Thread* thread)
+    : socket_(socket),
+      protocol_address_(protocol_address) {
+  request_manager_ = new StunRequestManager(thread);
+  request_manager_->SignalSendPacket.connect(this,
+                                             &RelayConnection::OnSendPacket);
+}
+
+RelayConnection::~RelayConnection() {
+  delete request_manager_;
+  delete socket_;
+}
+
+int RelayConnection::SetSocketOption(rtc::Socket::Option opt,
+                                     int value) {
+  if (socket_) {
+    return socket_->SetOption(opt, value);
+  }
+  return 0;
+}
+
+bool RelayConnection::CheckResponse(StunMessage* msg) {
+  return request_manager_->CheckResponse(msg);
+}
+
+void RelayConnection::OnSendPacket(const void* data, size_t size,
+                                   StunRequest* req) {
+  // TODO(mallinath) Find a way to get DSCP value from Port.
+  rtc::PacketOptions options;  // Default dscp set to NO_CHANGE.
+  int sent = socket_->SendTo(data, size, GetAddress(), options);
+  if (sent <= 0) {
+    LOG(LS_VERBOSE) << "OnSendPacket: failed sending to " << GetAddress() <<
+        strerror(socket_->GetError());
+    ASSERT(sent < 0);
+  }
+}
+
+int RelayConnection::Send(const void* pv, size_t cb,
+                          const rtc::PacketOptions& options) {
+  return socket_->SendTo(pv, cb, GetAddress(), options);
+}
+
+void RelayConnection::SendAllocateRequest(RelayEntry* entry, int delay) {
+  request_manager_->SendDelayed(new AllocateRequest(entry, this), delay);
+}
+
+RelayEntry::RelayEntry(RelayPort* port,
+                       const rtc::SocketAddress& ext_addr)
+    : port_(port), ext_addr_(ext_addr),
+      server_index_(0), connected_(false), locked_(false),
+      current_connection_(NULL) {
+}
+
+RelayEntry::~RelayEntry() {
+  // Remove all RelayConnections and dispose sockets.
+  delete current_connection_;
+  current_connection_ = NULL;
+}
+
+void RelayEntry::Connect() {
+  // If we're already connected, return.
+  if (connected_)
+    return;
+
+  // If we've exhausted all options, bail out.
+  const ProtocolAddress* ra = port()->ServerAddress(server_index_);
+  if (!ra) {
+    LOG(LS_WARNING) << "No more relay addresses left to try";
+    return;
+  }
+
+  // Remove any previous connection.
+  if (current_connection_) {
+    port()->thread()->Dispose(current_connection_);
+    current_connection_ = NULL;
+  }
+
+  // Try to set up our new socket.
+  LOG(LS_INFO) << "Connecting to relay via " << ProtoToString(ra->proto) <<
+      " @ " << ra->address.ToSensitiveString();
+
+  rtc::AsyncPacketSocket* socket = NULL;
+
+  if (ra->proto == PROTO_UDP) {
+    // UDP sockets are simple.
+    socket = port_->socket_factory()->CreateUdpSocket(
+        rtc::SocketAddress(port_->ip(), 0),
+        port_->min_port(), port_->max_port());
+  } else if (ra->proto == PROTO_TCP || ra->proto == PROTO_SSLTCP) {
+    int opts = (ra->proto == PROTO_SSLTCP) ?
+     rtc::PacketSocketFactory::OPT_SSLTCP : 0;
+    socket = port_->socket_factory()->CreateClientTcpSocket(
+        rtc::SocketAddress(port_->ip(), 0), ra->address,
+        port_->proxy(), port_->user_agent(), opts);
+  } else {
+    LOG(LS_WARNING) << "Unknown protocol (" << ra->proto << ")";
+  }
+
+  if (!socket) {
+    LOG(LS_WARNING) << "Socket creation failed";
+  }
+
+  // If we failed to get a socket, move on to the next protocol.
+  if (!socket) {
+    port()->thread()->Post(this, kMessageConnectTimeout);
+    return;
+  }
+
+  // Otherwise, create the new connection and configure any socket options.
+  socket->SignalReadPacket.connect(this, &RelayEntry::OnReadPacket);
+  socket->SignalReadyToSend.connect(this, &RelayEntry::OnReadyToSend);
+  current_connection_ = new RelayConnection(ra, socket, port()->thread());
+  for (size_t i = 0; i < port_->options().size(); ++i) {
+    current_connection_->SetSocketOption(port_->options()[i].first,
+                                         port_->options()[i].second);
+  }
+
+  // If we're trying UDP, start binding requests.
+  // If we're trying TCP, wait for connection with a fixed timeout.
+  if ((ra->proto == PROTO_TCP) || (ra->proto == PROTO_SSLTCP)) {
+    socket->SignalClose.connect(this, &RelayEntry::OnSocketClose);
+    socket->SignalConnect.connect(this, &RelayEntry::OnSocketConnect);
+    port()->thread()->PostDelayed(kSoftConnectTimeoutMs, this,
+                                  kMessageConnectTimeout);
+  } else {
+    current_connection_->SendAllocateRequest(this, 0);
+  }
+}
+
+int RelayEntry::GetError() {
+  if (current_connection_ != NULL) {
+    return current_connection_->GetError();
+  }
+  return 0;
+}
+
+RelayConnection* RelayEntry::GetBestConnection(RelayConnection* conn1,
+                                               RelayConnection* conn2) {
+  return conn1->GetProtocol() <= conn2->GetProtocol() ? conn1 : conn2;
+}
+
+void RelayEntry::OnConnect(const rtc::SocketAddress& mapped_addr,
+                           RelayConnection* connection) {
+  // We are connected, notify our parent.
+  ProtocolType proto = PROTO_UDP;
+  LOG(INFO) << "Relay allocate succeeded: " << ProtoToString(proto)
+            << " @ " << mapped_addr.ToSensitiveString();
+  connected_ = true;
+
+  port_->AddExternalAddress(ProtocolAddress(mapped_addr, proto));
+  port_->SetReady();
+}
+
+int RelayEntry::SendTo(const void* data, size_t size,
+                       const rtc::SocketAddress& addr,
+                       const rtc::PacketOptions& options) {
+  // If this connection is locked to the address given, then we can send the
+  // packet with no wrapper.
+  if (locked_ && (ext_addr_ == addr))
+    return SendPacket(data, size, options);
+
+  // Otherwise, we must wrap the given data in a STUN SEND request so that we
+  // can communicate the destination address to the server.
+  //
+  // Note that we do not use a StunRequest here.  This is because there is
+  // likely no reason to resend this packet. If it is late, we just drop it.
+  // The next send to this address will try again.
+
+  RelayMessage request;
+  request.SetType(STUN_SEND_REQUEST);
+
+  StunByteStringAttribute* magic_cookie_attr =
+      StunAttribute::CreateByteString(STUN_ATTR_MAGIC_COOKIE);
+  magic_cookie_attr->CopyBytes(TURN_MAGIC_COOKIE_VALUE,
+                               sizeof(TURN_MAGIC_COOKIE_VALUE));
+  VERIFY(request.AddAttribute(magic_cookie_attr));
+
+  StunByteStringAttribute* username_attr =
+      StunAttribute::CreateByteString(STUN_ATTR_USERNAME);
+  username_attr->CopyBytes(port_->username_fragment().c_str(),
+                           port_->username_fragment().size());
+  VERIFY(request.AddAttribute(username_attr));
+
+  StunAddressAttribute* addr_attr =
+      StunAttribute::CreateAddress(STUN_ATTR_DESTINATION_ADDRESS);
+  addr_attr->SetIP(addr.ipaddr());
+  addr_attr->SetPort(addr.port());
+  VERIFY(request.AddAttribute(addr_attr));
+
+  // Attempt to lock
+  if (ext_addr_ == addr) {
+    StunUInt32Attribute* options_attr =
+      StunAttribute::CreateUInt32(STUN_ATTR_OPTIONS);
+    options_attr->SetValue(0x1);
+    VERIFY(request.AddAttribute(options_attr));
+  }
+
+  StunByteStringAttribute* data_attr =
+      StunAttribute::CreateByteString(STUN_ATTR_DATA);
+  data_attr->CopyBytes(data, size);
+  VERIFY(request.AddAttribute(data_attr));
+
+  // TODO: compute the HMAC.
+
+  rtc::ByteBuffer buf;
+  request.Write(&buf);
+
+  return SendPacket(buf.Data(), buf.Length(), options);
+}
+
+void RelayEntry::ScheduleKeepAlive() {
+  if (current_connection_) {
+    current_connection_->SendAllocateRequest(this, kKeepAliveDelay);
+  }
+}
+
+int RelayEntry::SetSocketOption(rtc::Socket::Option opt, int value) {
+  // Set the option on all available sockets.
+  int socket_error = 0;
+  if (current_connection_) {
+    socket_error = current_connection_->SetSocketOption(opt, value);
+  }
+  return socket_error;
+}
+
+void RelayEntry::HandleConnectFailure(
+    rtc::AsyncPacketSocket* socket) {
+  // Make sure it's the current connection that has failed, it might
+  // be an old socked that has not yet been disposed.
+  if (!socket ||
+      (current_connection_ && socket == current_connection_->socket())) {
+    if (current_connection_)
+      port()->SignalConnectFailure(current_connection_->protocol_address());
+
+    // Try to connect to the next server address.
+    server_index_ += 1;
+    Connect();
+  }
+}
+
+void RelayEntry::OnMessage(rtc::Message *pmsg) {
+  ASSERT(pmsg->message_id == kMessageConnectTimeout);
+  if (current_connection_) {
+    const ProtocolAddress* ra = current_connection_->protocol_address();
+    LOG(LS_WARNING) << "Relay " << ra->proto << " connection to " <<
+        ra->address << " timed out";
+
+    // Currently we connect to each server address in sequence. If we
+    // have more addresses to try, treat this is an error and move on to
+    // the next address, otherwise give this connection more time and
+    // await the real timeout.
+    //
+    // TODO: Connect to servers in parallel to speed up connect time
+    // and to avoid giving up too early.
+    port_->SignalSoftTimeout(ra);
+    HandleConnectFailure(current_connection_->socket());
+  } else {
+    HandleConnectFailure(NULL);
+  }
+}
+
+void RelayEntry::OnSocketConnect(rtc::AsyncPacketSocket* socket) {
+  LOG(INFO) << "relay tcp connected to " <<
+      socket->GetRemoteAddress().ToSensitiveString();
+  if (current_connection_ != NULL) {
+    current_connection_->SendAllocateRequest(this, 0);
+  }
+}
+
+void RelayEntry::OnSocketClose(rtc::AsyncPacketSocket* socket,
+                               int error) {
+  PLOG(LERROR, error) << "Relay connection failed: socket closed";
+  HandleConnectFailure(socket);
+}
+
+void RelayEntry::OnReadPacket(
+    rtc::AsyncPacketSocket* socket,
+    const char* data, size_t size,
+    const rtc::SocketAddress& remote_addr,
+    const rtc::PacketTime& packet_time) {
+  // ASSERT(remote_addr == port_->server_addr());
+  // TODO: are we worried about this?
+
+  if (current_connection_ == NULL || socket != current_connection_->socket()) {
+    // This packet comes from an unknown address.
+    LOG(WARNING) << "Dropping packet: unknown address";
+    return;
+  }
+
+  // If the magic cookie is not present, then this is an unwrapped packet sent
+  // by the server,  The actual remote address is the one we recorded.
+  if (!port_->HasMagicCookie(data, size)) {
+    if (locked_) {
+      port_->OnReadPacket(data, size, ext_addr_, PROTO_UDP, packet_time);
+    } else {
+      LOG(WARNING) << "Dropping packet: entry not locked";
+    }
+    return;
+  }
+
+  rtc::ByteBuffer buf(data, size);
+  RelayMessage msg;
+  if (!msg.Read(&buf)) {
+    LOG(INFO) << "Incoming packet was not STUN";
+    return;
+  }
+
+  // The incoming packet should be a STUN ALLOCATE response, SEND response, or
+  // DATA indication.
+  if (current_connection_->CheckResponse(&msg)) {
+    return;
+  } else if (msg.type() == STUN_SEND_RESPONSE) {
+    if (const StunUInt32Attribute* options_attr =
+        msg.GetUInt32(STUN_ATTR_OPTIONS)) {
+      if (options_attr->value() & 0x1) {
+        locked_ = true;
+      }
+    }
+    return;
+  } else if (msg.type() != STUN_DATA_INDICATION) {
+    LOG(INFO) << "Received BAD stun type from server: " << msg.type();
+    return;
+  }
+
+  // This must be a data indication.
+
+  const StunAddressAttribute* addr_attr =
+      msg.GetAddress(STUN_ATTR_SOURCE_ADDRESS2);
+  if (!addr_attr) {
+    LOG(INFO) << "Data indication has no source address";
+    return;
+  } else if (addr_attr->family() != 1) {
+    LOG(INFO) << "Source address has bad family";
+    return;
+  }
+
+  rtc::SocketAddress remote_addr2(addr_attr->ipaddr(), addr_attr->port());
+
+  const StunByteStringAttribute* data_attr = msg.GetByteString(STUN_ATTR_DATA);
+  if (!data_attr) {
+    LOG(INFO) << "Data indication has no data";
+    return;
+  }
+
+  // Process the actual data and remote address in the normal manner.
+  port_->OnReadPacket(data_attr->bytes(), data_attr->length(), remote_addr2,
+                      PROTO_UDP, packet_time);
+}
+
+void RelayEntry::OnReadyToSend(rtc::AsyncPacketSocket* socket) {
+  if (connected()) {
+    port_->OnReadyToSend();
+  }
+}
+
+int RelayEntry::SendPacket(const void* data, size_t size,
+                           const rtc::PacketOptions& options) {
+  int sent = 0;
+  if (current_connection_) {
+    // We are connected, no need to send packets anywere else than to
+    // the current connection.
+    sent = current_connection_->Send(data, size, options);
+  }
+  return sent;
+}
+
+AllocateRequest::AllocateRequest(RelayEntry* entry,
+                                 RelayConnection* connection)
+    : StunRequest(new RelayMessage()),
+      entry_(entry),
+      connection_(connection) {
+  start_time_ = rtc::Time();
+}
+
+void AllocateRequest::Prepare(StunMessage* request) {
+  request->SetType(STUN_ALLOCATE_REQUEST);
+
+  StunByteStringAttribute* username_attr =
+      StunAttribute::CreateByteString(STUN_ATTR_USERNAME);
+  username_attr->CopyBytes(
+      entry_->port()->username_fragment().c_str(),
+      entry_->port()->username_fragment().size());
+  VERIFY(request->AddAttribute(username_attr));
+}
+
+int AllocateRequest::GetNextDelay() {
+  int delay = 100 * rtc::_max(1 << count_, 2);
+  count_ += 1;
+  if (count_ == 5)
+    timeout_ = true;
+  return delay;
+}
+
+void AllocateRequest::OnResponse(StunMessage* response) {
+  const StunAddressAttribute* addr_attr =
+      response->GetAddress(STUN_ATTR_MAPPED_ADDRESS);
+  if (!addr_attr) {
+    LOG(INFO) << "Allocate response missing mapped address.";
+  } else if (addr_attr->family() != 1) {
+    LOG(INFO) << "Mapped address has bad family";
+  } else {
+    rtc::SocketAddress addr(addr_attr->ipaddr(), addr_attr->port());
+    entry_->OnConnect(addr, connection_);
+  }
+
+  // We will do a keep-alive regardless of whether this request suceeds.
+  // This should have almost no impact on network usage.
+  entry_->ScheduleKeepAlive();
+}
+
+void AllocateRequest::OnErrorResponse(StunMessage* response) {
+  const StunErrorCodeAttribute* attr = response->GetErrorCode();
+  if (!attr) {
+    LOG(INFO) << "Bad allocate response error code";
+  } else {
+    LOG(INFO) << "Allocate error response:"
+              << " code=" << attr->code()
+              << " reason='" << attr->reason() << "'";
+  }
+
+  if (rtc::TimeSince(start_time_) <= kRetryTimeout)
+    entry_->ScheduleKeepAlive();
+}
+
+void AllocateRequest::OnTimeout() {
+  LOG(INFO) << "Allocate request timed out";
+  entry_->HandleConnectFailure(connection_->socket());
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/relayport.h b/webrtc/p2p/base/relayport.h
new file mode 100644
index 0000000..3d9538d
--- /dev/null
+++ b/webrtc/p2p/base/relayport.h
@@ -0,0 +1,101 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_RELAYPORT_H_
+#define WEBRTC_P2P_BASE_RELAYPORT_H_
+
+#include <deque>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "webrtc/p2p/base/port.h"
+#include "webrtc/p2p/base/stunrequest.h"
+
+namespace cricket {
+
+class RelayEntry;
+class RelayConnection;
+
+// Communicates using an allocated port on the relay server. For each
+// remote candidate that we try to send data to a RelayEntry instance
+// is created. The RelayEntry will try to reach the remote destination
+// by connecting to all available server addresses in a pre defined
+// order with a small delay in between. When a connection is
+// successful all other connection attemts are aborted.
+class RelayPort : public Port {
+ public:
+  typedef std::pair<rtc::Socket::Option, int> OptionValue;
+
+  // RelayPort doesn't yet do anything fancy in the ctor.
+  static RelayPort* Create(
+      rtc::Thread* thread, rtc::PacketSocketFactory* factory,
+      rtc::Network* network, const rtc::IPAddress& ip,
+      int min_port, int max_port, const std::string& username,
+      const std::string& password) {
+    return new RelayPort(thread, factory, network, ip, min_port, max_port,
+                         username, password);
+  }
+  virtual ~RelayPort();
+
+  void AddServerAddress(const ProtocolAddress& addr);
+  void AddExternalAddress(const ProtocolAddress& addr);
+
+  const std::vector<OptionValue>& options() const { return options_; }
+  bool HasMagicCookie(const char* data, size_t size);
+
+  virtual void PrepareAddress();
+  virtual Connection* CreateConnection(const Candidate& address,
+                                       CandidateOrigin origin);
+  virtual int SetOption(rtc::Socket::Option opt, int value);
+  virtual int GetOption(rtc::Socket::Option opt, int* value);
+  virtual int GetError();
+
+  const ProtocolAddress * ServerAddress(size_t index) const;
+  bool IsReady() { return ready_; }
+
+  // Used for testing.
+  sigslot::signal1<const ProtocolAddress*> SignalConnectFailure;
+  sigslot::signal1<const ProtocolAddress*> SignalSoftTimeout;
+
+ protected:
+  RelayPort(rtc::Thread* thread, rtc::PacketSocketFactory* factory,
+            rtc::Network*, const rtc::IPAddress& ip,
+            int min_port, int max_port, const std::string& username,
+            const std::string& password);
+  bool Init();
+
+  void SetReady();
+
+  virtual int SendTo(const void* data, size_t size,
+                     const rtc::SocketAddress& addr,
+                     const rtc::PacketOptions& options,
+                     bool payload);
+
+  // Dispatches the given packet to the port or connection as appropriate.
+  void OnReadPacket(const char* data, size_t size,
+                    const rtc::SocketAddress& remote_addr,
+                    ProtocolType proto,
+                    const rtc::PacketTime& packet_time);
+
+ private:
+  friend class RelayEntry;
+
+  std::deque<ProtocolAddress> server_addr_;
+  std::vector<ProtocolAddress> external_addr_;
+  bool ready_;
+  std::vector<RelayEntry*> entries_;
+  std::vector<OptionValue> options_;
+  int error_;
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_RELAYPORT_H_
diff --git a/webrtc/p2p/base/relayport_unittest.cc b/webrtc/p2p/base/relayport_unittest.cc
new file mode 100644
index 0000000..d644d67
--- /dev/null
+++ b/webrtc/p2p/base/relayport_unittest.cc
@@ -0,0 +1,272 @@
+/*
+ *  Copyright 2009 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/basicpacketsocketfactory.h"
+#include "webrtc/p2p/base/relayport.h"
+#include "webrtc/p2p/base/relayserver.h"
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/helpers.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/physicalsocketserver.h"
+#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/socketadapters.h"
+#include "webrtc/base/socketaddress.h"
+#include "webrtc/base/ssladapter.h"
+#include "webrtc/base/thread.h"
+#include "webrtc/base/virtualsocketserver.h"
+
+using rtc::SocketAddress;
+
+static const SocketAddress kLocalAddress = SocketAddress("192.168.1.2", 0);
+static const SocketAddress kRelayUdpAddr = SocketAddress("99.99.99.1", 5000);
+static const SocketAddress kRelayTcpAddr = SocketAddress("99.99.99.2", 5001);
+static const SocketAddress kRelaySslAddr = SocketAddress("99.99.99.3", 443);
+static const SocketAddress kRelayExtAddr = SocketAddress("99.99.99.3", 5002);
+
+static const int kTimeoutMs = 1000;
+static const int kMaxTimeoutMs = 5000;
+
+// Tests connecting a RelayPort to a fake relay server
+// (cricket::RelayServer) using all currently available protocols. The
+// network layer is faked out by using a VirtualSocketServer for
+// creating sockets. The test will monitor the current state of the
+// RelayPort and created sockets by listening for signals such as,
+// SignalConnectFailure, SignalConnectTimeout, SignalSocketClosed and
+// SignalReadPacket.
+class RelayPortTest : public testing::Test,
+                      public sigslot::has_slots<> {
+ public:
+  RelayPortTest()
+      : main_(rtc::Thread::Current()),
+        physical_socket_server_(new rtc::PhysicalSocketServer),
+        virtual_socket_server_(new rtc::VirtualSocketServer(
+            physical_socket_server_.get())),
+        ss_scope_(virtual_socket_server_.get()),
+        network_("unittest", "unittest", rtc::IPAddress(INADDR_ANY), 32),
+        socket_factory_(rtc::Thread::Current()),
+        username_(rtc::CreateRandomString(16)),
+        password_(rtc::CreateRandomString(16)),
+        relay_port_(cricket::RelayPort::Create(main_, &socket_factory_,
+                                               &network_,
+                                               kLocalAddress.ipaddr(),
+                                               0, 0, username_, password_)),
+        relay_server_(new cricket::RelayServer(main_)) {
+  }
+
+  void OnReadPacket(rtc::AsyncPacketSocket* socket,
+                    const char* data, size_t size,
+                    const rtc::SocketAddress& remote_addr,
+                    const rtc::PacketTime& packet_time) {
+    received_packet_count_[socket]++;
+  }
+
+  void OnConnectFailure(const cricket::ProtocolAddress* addr) {
+    failed_connections_.push_back(*addr);
+  }
+
+  void OnSoftTimeout(const cricket::ProtocolAddress* addr) {
+    soft_timedout_connections_.push_back(*addr);
+  }
+
+ protected:
+  virtual void SetUp() {
+    // The relay server needs an external socket to work properly.
+    rtc::AsyncUDPSocket* ext_socket =
+        CreateAsyncUdpSocket(kRelayExtAddr);
+    relay_server_->AddExternalSocket(ext_socket);
+
+    // Listen for failures.
+    relay_port_->SignalConnectFailure.
+        connect(this, &RelayPortTest::OnConnectFailure);
+
+    // Listen for soft timeouts.
+    relay_port_->SignalSoftTimeout.
+        connect(this, &RelayPortTest::OnSoftTimeout);
+  }
+
+  // Udp has the highest 'goodness' value of the three different
+  // protocols used for connecting to the relay server. As soon as
+  // PrepareAddress is called, the RelayPort will start trying to
+  // connect to the given UDP address. As soon as a response to the
+  // sent STUN allocate request message has been received, the
+  // RelayPort will consider the connection to be complete and will
+  // abort any other connection attempts.
+  void TestConnectUdp() {
+    // Add a UDP socket to the relay server.
+    rtc::AsyncUDPSocket* internal_udp_socket =
+        CreateAsyncUdpSocket(kRelayUdpAddr);
+    rtc::AsyncSocket* server_socket = CreateServerSocket(kRelayTcpAddr);
+
+    relay_server_->AddInternalSocket(internal_udp_socket);
+    relay_server_->AddInternalServerSocket(server_socket, cricket::PROTO_TCP);
+
+    // Now add our relay addresses to the relay port and let it start.
+    relay_port_->AddServerAddress(
+        cricket::ProtocolAddress(kRelayUdpAddr, cricket::PROTO_UDP));
+    relay_port_->AddServerAddress(
+        cricket::ProtocolAddress(kRelayTcpAddr, cricket::PROTO_TCP));
+    relay_port_->PrepareAddress();
+
+    // Should be connected.
+    EXPECT_TRUE_WAIT(relay_port_->IsReady(), kTimeoutMs);
+
+    // Make sure that we are happy with UDP, ie. not continuing with
+    // TCP, SSLTCP, etc.
+    WAIT(relay_server_->HasConnection(kRelayTcpAddr), kTimeoutMs);
+
+    // Should have only one connection.
+    EXPECT_EQ(1, relay_server_->GetConnectionCount());
+
+    // Should be the UDP address.
+    EXPECT_TRUE(relay_server_->HasConnection(kRelayUdpAddr));
+  }
+
+  // TCP has the second best 'goodness' value, and as soon as UDP
+  // connection has failed, the RelayPort will attempt to connect via
+  // TCP. Here we add a fake UDP address together with a real TCP
+  // address to simulate an UDP failure. As soon as UDP has failed the
+  // RelayPort will try the TCP adress and succed.
+  void TestConnectTcp() {
+    // Create a fake UDP address for relay port to simulate a failure.
+    cricket::ProtocolAddress fake_protocol_address =
+        cricket::ProtocolAddress(kRelayUdpAddr, cricket::PROTO_UDP);
+
+    // Create a server socket for the RelayServer.
+    rtc::AsyncSocket* server_socket = CreateServerSocket(kRelayTcpAddr);
+    relay_server_->AddInternalServerSocket(server_socket, cricket::PROTO_TCP);
+
+    // Add server addresses to the relay port and let it start.
+    relay_port_->AddServerAddress(
+        cricket::ProtocolAddress(fake_protocol_address));
+    relay_port_->AddServerAddress(
+        cricket::ProtocolAddress(kRelayTcpAddr, cricket::PROTO_TCP));
+    relay_port_->PrepareAddress();
+
+    EXPECT_FALSE(relay_port_->IsReady());
+
+    // Should have timed out in 200 + 200 + 400 + 800 + 1600 ms.
+    EXPECT_TRUE_WAIT(HasFailed(&fake_protocol_address), 3600);
+
+    // Wait until relayport is ready.
+    EXPECT_TRUE_WAIT(relay_port_->IsReady(), kMaxTimeoutMs);
+
+    // Should have only one connection.
+    EXPECT_EQ(1, relay_server_->GetConnectionCount());
+
+    // Should be the TCP address.
+    EXPECT_TRUE(relay_server_->HasConnection(kRelayTcpAddr));
+  }
+
+  void TestConnectSslTcp() {
+    // Create a fake TCP address for relay port to simulate a failure.
+    // We skip UDP here since transition from UDP to TCP has been
+    // tested above.
+    cricket::ProtocolAddress fake_protocol_address =
+        cricket::ProtocolAddress(kRelayTcpAddr, cricket::PROTO_TCP);
+
+    // Create a ssl server socket for the RelayServer.
+    rtc::AsyncSocket* ssl_server_socket =
+        CreateServerSocket(kRelaySslAddr);
+    relay_server_->AddInternalServerSocket(ssl_server_socket,
+                                           cricket::PROTO_SSLTCP);
+
+    // Create a tcp server socket that listens on the fake address so
+    // the relay port can attempt to connect to it.
+    rtc::scoped_ptr<rtc::AsyncSocket> tcp_server_socket(
+        CreateServerSocket(kRelayTcpAddr));
+
+    // Add server addresses to the relay port and let it start.
+    relay_port_->AddServerAddress(fake_protocol_address);
+    relay_port_->AddServerAddress(
+        cricket::ProtocolAddress(kRelaySslAddr, cricket::PROTO_SSLTCP));
+    relay_port_->PrepareAddress();
+    EXPECT_FALSE(relay_port_->IsReady());
+
+    // Should have timed out in 3000 ms(relayport.cc, kSoftConnectTimeoutMs).
+    EXPECT_TRUE_WAIT_MARGIN(HasTimedOut(&fake_protocol_address), 3000, 100);
+
+    // Wait until relayport is ready.
+    EXPECT_TRUE_WAIT(relay_port_->IsReady(), kMaxTimeoutMs);
+
+    // Should have only one connection.
+    EXPECT_EQ(1, relay_server_->GetConnectionCount());
+
+    // Should be the SSLTCP address.
+    EXPECT_TRUE(relay_server_->HasConnection(kRelaySslAddr));
+  }
+
+ private:
+  rtc::AsyncUDPSocket* CreateAsyncUdpSocket(const SocketAddress addr) {
+    rtc::AsyncSocket* socket =
+        virtual_socket_server_->CreateAsyncSocket(SOCK_DGRAM);
+    rtc::AsyncUDPSocket* packet_socket =
+        rtc::AsyncUDPSocket::Create(socket, addr);
+    EXPECT_TRUE(packet_socket != NULL);
+    packet_socket->SignalReadPacket.connect(this, &RelayPortTest::OnReadPacket);
+    return packet_socket;
+  }
+
+  rtc::AsyncSocket* CreateServerSocket(const SocketAddress addr) {
+    rtc::AsyncSocket* socket =
+        virtual_socket_server_->CreateAsyncSocket(SOCK_STREAM);
+    EXPECT_GE(socket->Bind(addr), 0);
+    EXPECT_GE(socket->Listen(5), 0);
+    return socket;
+  }
+
+  bool HasFailed(cricket::ProtocolAddress* addr) {
+    for (size_t i = 0; i < failed_connections_.size(); i++) {
+      if (failed_connections_[i].address == addr->address &&
+          failed_connections_[i].proto == addr->proto) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  bool HasTimedOut(cricket::ProtocolAddress* addr) {
+    for (size_t i = 0; i < soft_timedout_connections_.size(); i++) {
+      if (soft_timedout_connections_[i].address == addr->address &&
+          soft_timedout_connections_[i].proto == addr->proto) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  typedef std::map<rtc::AsyncPacketSocket*, int> PacketMap;
+
+  rtc::Thread* main_;
+  rtc::scoped_ptr<rtc::PhysicalSocketServer>
+      physical_socket_server_;
+  rtc::scoped_ptr<rtc::VirtualSocketServer> virtual_socket_server_;
+  rtc::SocketServerScope ss_scope_;
+  rtc::Network network_;
+  rtc::BasicPacketSocketFactory socket_factory_;
+  std::string username_;
+  std::string password_;
+  rtc::scoped_ptr<cricket::RelayPort> relay_port_;
+  rtc::scoped_ptr<cricket::RelayServer> relay_server_;
+  std::vector<cricket::ProtocolAddress> failed_connections_;
+  std::vector<cricket::ProtocolAddress> soft_timedout_connections_;
+  PacketMap received_packet_count_;
+};
+
+TEST_F(RelayPortTest, ConnectUdp) {
+  TestConnectUdp();
+}
+
+TEST_F(RelayPortTest, ConnectTcp) {
+  TestConnectTcp();
+}
+
+TEST_F(RelayPortTest, ConnectSslTcp) {
+  TestConnectSslTcp();
+}
diff --git a/webrtc/p2p/base/relayserver.cc b/webrtc/p2p/base/relayserver.cc
new file mode 100644
index 0000000..e37a168
--- /dev/null
+++ b/webrtc/p2p/base/relayserver.cc
@@ -0,0 +1,746 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/relayserver.h"
+
+#ifdef WEBRTC_POSIX
+#include <errno.h>
+#endif  // WEBRTC_POSIX
+
+#include <algorithm>
+
+#include "webrtc/base/asynctcpsocket.h"
+#include "webrtc/base/helpers.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/socketadapters.h"
+
+namespace cricket {
+
+// By default, we require a ping every 90 seconds.
+const int MAX_LIFETIME = 15 * 60 * 1000;
+
+// The number of bytes in each of the usernames we use.
+const uint32 USERNAME_LENGTH = 16;
+
+// Calls SendTo on the given socket and logs any bad results.
+void Send(rtc::AsyncPacketSocket* socket, const char* bytes, size_t size,
+          const rtc::SocketAddress& addr) {
+  rtc::PacketOptions options;
+  int result = socket->SendTo(bytes, size, addr, options);
+  if (result < static_cast<int>(size)) {
+    LOG(LS_ERROR) << "SendTo wrote only " << result << " of " << size
+                  << " bytes";
+  } else if (result < 0) {
+    LOG_ERR(LS_ERROR) << "SendTo";
+  }
+}
+
+// Sends the given STUN message on the given socket.
+void SendStun(const StunMessage& msg,
+              rtc::AsyncPacketSocket* socket,
+              const rtc::SocketAddress& addr) {
+  rtc::ByteBuffer buf;
+  msg.Write(&buf);
+  Send(socket, buf.Data(), buf.Length(), addr);
+}
+
+// Constructs a STUN error response and sends it on the given socket.
+void SendStunError(const StunMessage& msg, rtc::AsyncPacketSocket* socket,
+                   const rtc::SocketAddress& remote_addr, int error_code,
+                   const char* error_desc, const std::string& magic_cookie) {
+  RelayMessage err_msg;
+  err_msg.SetType(GetStunErrorResponseType(msg.type()));
+  err_msg.SetTransactionID(msg.transaction_id());
+
+  StunByteStringAttribute* magic_cookie_attr =
+      StunAttribute::CreateByteString(cricket::STUN_ATTR_MAGIC_COOKIE);
+  if (magic_cookie.size() == 0) {
+    magic_cookie_attr->CopyBytes(cricket::TURN_MAGIC_COOKIE_VALUE,
+                                 sizeof(cricket::TURN_MAGIC_COOKIE_VALUE));
+  } else {
+    magic_cookie_attr->CopyBytes(magic_cookie.c_str(), magic_cookie.size());
+  }
+  err_msg.AddAttribute(magic_cookie_attr);
+
+  StunErrorCodeAttribute* err_code = StunAttribute::CreateErrorCode();
+  err_code->SetClass(error_code / 100);
+  err_code->SetNumber(error_code % 100);
+  err_code->SetReason(error_desc);
+  err_msg.AddAttribute(err_code);
+
+  SendStun(err_msg, socket, remote_addr);
+}
+
+RelayServer::RelayServer(rtc::Thread* thread)
+  : thread_(thread), log_bindings_(true) {
+}
+
+RelayServer::~RelayServer() {
+  // Deleting the binding will cause it to be removed from the map.
+  while (!bindings_.empty())
+    delete bindings_.begin()->second;
+  for (size_t i = 0; i < internal_sockets_.size(); ++i)
+    delete internal_sockets_[i];
+  for (size_t i = 0; i < external_sockets_.size(); ++i)
+    delete external_sockets_[i];
+  for (size_t i = 0; i < removed_sockets_.size(); ++i)
+    delete removed_sockets_[i];
+  while (!server_sockets_.empty()) {
+    rtc::AsyncSocket* socket = server_sockets_.begin()->first;
+    server_sockets_.erase(server_sockets_.begin()->first);
+    delete socket;
+  }
+}
+
+void RelayServer::AddInternalSocket(rtc::AsyncPacketSocket* socket) {
+  ASSERT(internal_sockets_.end() ==
+      std::find(internal_sockets_.begin(), internal_sockets_.end(), socket));
+  internal_sockets_.push_back(socket);
+  socket->SignalReadPacket.connect(this, &RelayServer::OnInternalPacket);
+}
+
+void RelayServer::RemoveInternalSocket(rtc::AsyncPacketSocket* socket) {
+  SocketList::iterator iter =
+      std::find(internal_sockets_.begin(), internal_sockets_.end(), socket);
+  ASSERT(iter != internal_sockets_.end());
+  internal_sockets_.erase(iter);
+  removed_sockets_.push_back(socket);
+  socket->SignalReadPacket.disconnect(this);
+}
+
+void RelayServer::AddExternalSocket(rtc::AsyncPacketSocket* socket) {
+  ASSERT(external_sockets_.end() ==
+      std::find(external_sockets_.begin(), external_sockets_.end(), socket));
+  external_sockets_.push_back(socket);
+  socket->SignalReadPacket.connect(this, &RelayServer::OnExternalPacket);
+}
+
+void RelayServer::RemoveExternalSocket(rtc::AsyncPacketSocket* socket) {
+  SocketList::iterator iter =
+      std::find(external_sockets_.begin(), external_sockets_.end(), socket);
+  ASSERT(iter != external_sockets_.end());
+  external_sockets_.erase(iter);
+  removed_sockets_.push_back(socket);
+  socket->SignalReadPacket.disconnect(this);
+}
+
+void RelayServer::AddInternalServerSocket(rtc::AsyncSocket* socket,
+                                          cricket::ProtocolType proto) {
+  ASSERT(server_sockets_.end() ==
+         server_sockets_.find(socket));
+  server_sockets_[socket] = proto;
+  socket->SignalReadEvent.connect(this, &RelayServer::OnReadEvent);
+}
+
+void RelayServer::RemoveInternalServerSocket(
+    rtc::AsyncSocket* socket) {
+  ServerSocketMap::iterator iter = server_sockets_.find(socket);
+  ASSERT(iter != server_sockets_.end());
+  server_sockets_.erase(iter);
+  socket->SignalReadEvent.disconnect(this);
+}
+
+int RelayServer::GetConnectionCount() const {
+  return static_cast<int>(connections_.size());
+}
+
+rtc::SocketAddressPair RelayServer::GetConnection(int connection) const {
+  int i = 0;
+  for (ConnectionMap::const_iterator it = connections_.begin();
+       it != connections_.end(); ++it) {
+    if (i == connection) {
+      return it->second->addr_pair();
+    }
+    ++i;
+  }
+  return rtc::SocketAddressPair();
+}
+
+bool RelayServer::HasConnection(const rtc::SocketAddress& address) const {
+  for (ConnectionMap::const_iterator it = connections_.begin();
+       it != connections_.end(); ++it) {
+    if (it->second->addr_pair().destination() == address) {
+      return true;
+    }
+  }
+  return false;
+}
+
+void RelayServer::OnReadEvent(rtc::AsyncSocket* socket) {
+  ASSERT(server_sockets_.find(socket) != server_sockets_.end());
+  AcceptConnection(socket);
+}
+
+void RelayServer::OnInternalPacket(
+    rtc::AsyncPacketSocket* socket, const char* bytes, size_t size,
+    const rtc::SocketAddress& remote_addr,
+    const rtc::PacketTime& packet_time) {
+
+  // Get the address of the connection we just received on.
+  rtc::SocketAddressPair ap(remote_addr, socket->GetLocalAddress());
+  ASSERT(!ap.destination().IsNil());
+
+  // If this did not come from an existing connection, it should be a STUN
+  // allocate request.
+  ConnectionMap::iterator piter = connections_.find(ap);
+  if (piter == connections_.end()) {
+    HandleStunAllocate(bytes, size, ap, socket);
+    return;
+  }
+
+  RelayServerConnection* int_conn = piter->second;
+
+  // Handle STUN requests to the server itself.
+  if (int_conn->binding()->HasMagicCookie(bytes, size)) {
+    HandleStun(int_conn, bytes, size);
+    return;
+  }
+
+  // Otherwise, this is a non-wrapped packet that we are to forward.  Make sure
+  // that this connection has been locked.  (Otherwise, we would not know what
+  // address to forward to.)
+  if (!int_conn->locked()) {
+    LOG(LS_WARNING) << "Dropping packet: connection not locked";
+    return;
+  }
+
+  // Forward this to the destination address into the connection.
+  RelayServerConnection* ext_conn = int_conn->binding()->GetExternalConnection(
+      int_conn->default_destination());
+  if (ext_conn && ext_conn->locked()) {
+    // TODO: Check the HMAC.
+    ext_conn->Send(bytes, size);
+  } else {
+    // This happens very often and is not an error.
+    LOG(LS_INFO) << "Dropping packet: no external connection";
+  }
+}
+
+void RelayServer::OnExternalPacket(
+    rtc::AsyncPacketSocket* socket, const char* bytes, size_t size,
+    const rtc::SocketAddress& remote_addr,
+    const rtc::PacketTime& packet_time) {
+
+  // Get the address of the connection we just received on.
+  rtc::SocketAddressPair ap(remote_addr, socket->GetLocalAddress());
+  ASSERT(!ap.destination().IsNil());
+
+  // If this connection already exists, then forward the traffic.
+  ConnectionMap::iterator piter = connections_.find(ap);
+  if (piter != connections_.end()) {
+    // TODO: Check the HMAC.
+    RelayServerConnection* ext_conn = piter->second;
+    RelayServerConnection* int_conn =
+        ext_conn->binding()->GetInternalConnection(
+            ext_conn->addr_pair().source());
+    ASSERT(int_conn != NULL);
+    int_conn->Send(bytes, size, ext_conn->addr_pair().source());
+    ext_conn->Lock();  // allow outgoing packets
+    return;
+  }
+
+  // The first packet should always be a STUN / TURN packet.  If it isn't, then
+  // we should just ignore this packet.
+  RelayMessage msg;
+  rtc::ByteBuffer buf(bytes, size);
+  if (!msg.Read(&buf)) {
+    LOG(LS_WARNING) << "Dropping packet: first packet not STUN";
+    return;
+  }
+
+  // The initial packet should have a username (which identifies the binding).
+  const StunByteStringAttribute* username_attr =
+      msg.GetByteString(STUN_ATTR_USERNAME);
+  if (!username_attr) {
+    LOG(LS_WARNING) << "Dropping packet: no username";
+    return;
+  }
+
+  uint32 length = rtc::_min(static_cast<uint32>(username_attr->length()),
+                                  USERNAME_LENGTH);
+  std::string username(username_attr->bytes(), length);
+  // TODO: Check the HMAC.
+
+  // The binding should already be present.
+  BindingMap::iterator biter = bindings_.find(username);
+  if (biter == bindings_.end()) {
+    LOG(LS_WARNING) << "Dropping packet: no binding with username";
+    return;
+  }
+
+  // Add this authenticted connection to the binding.
+  RelayServerConnection* ext_conn =
+      new RelayServerConnection(biter->second, ap, socket);
+  ext_conn->binding()->AddExternalConnection(ext_conn);
+  AddConnection(ext_conn);
+
+  // We always know where external packets should be forwarded, so we can lock
+  // them from the beginning.
+  ext_conn->Lock();
+
+  // Send this message on the appropriate internal connection.
+  RelayServerConnection* int_conn = ext_conn->binding()->GetInternalConnection(
+      ext_conn->addr_pair().source());
+  ASSERT(int_conn != NULL);
+  int_conn->Send(bytes, size, ext_conn->addr_pair().source());
+}
+
+bool RelayServer::HandleStun(
+    const char* bytes, size_t size, const rtc::SocketAddress& remote_addr,
+    rtc::AsyncPacketSocket* socket, std::string* username,
+    StunMessage* msg) {
+
+  // Parse this into a stun message. Eat the message if this fails.
+  rtc::ByteBuffer buf(bytes, size);
+  if (!msg->Read(&buf)) {
+    return false;
+  }
+
+  // The initial packet should have a username (which identifies the binding).
+  const StunByteStringAttribute* username_attr =
+      msg->GetByteString(STUN_ATTR_USERNAME);
+  if (!username_attr) {
+    SendStunError(*msg, socket, remote_addr, 432, "Missing Username", "");
+    return false;
+  }
+
+  // Record the username if requested.
+  if (username)
+    username->append(username_attr->bytes(), username_attr->length());
+
+  // TODO: Check for unknown attributes (<= 0x7fff)
+
+  return true;
+}
+
+void RelayServer::HandleStunAllocate(
+    const char* bytes, size_t size, const rtc::SocketAddressPair& ap,
+    rtc::AsyncPacketSocket* socket) {
+
+  // Make sure this is a valid STUN request.
+  RelayMessage request;
+  std::string username;
+  if (!HandleStun(bytes, size, ap.source(), socket, &username, &request))
+    return;
+
+  // Make sure this is a an allocate request.
+  if (request.type() != STUN_ALLOCATE_REQUEST) {
+    SendStunError(request,
+                  socket,
+                  ap.source(),
+                  600,
+                  "Operation Not Supported",
+                  "");
+    return;
+  }
+
+  // TODO: Check the HMAC.
+
+  // Find or create the binding for this username.
+
+  RelayServerBinding* binding;
+
+  BindingMap::iterator biter = bindings_.find(username);
+  if (biter != bindings_.end()) {
+    binding = biter->second;
+  } else {
+    // NOTE: In the future, bindings will be created by the bot only.  This
+    //       else-branch will then disappear.
+
+    // Compute the appropriate lifetime for this binding.
+    uint32 lifetime = MAX_LIFETIME;
+    const StunUInt32Attribute* lifetime_attr =
+        request.GetUInt32(STUN_ATTR_LIFETIME);
+    if (lifetime_attr)
+      lifetime = rtc::_min(lifetime, lifetime_attr->value() * 1000);
+
+    binding = new RelayServerBinding(this, username, "0", lifetime);
+    binding->SignalTimeout.connect(this, &RelayServer::OnTimeout);
+    bindings_[username] = binding;
+
+    if (log_bindings_) {
+      LOG(LS_INFO) << "Added new binding " << username << ", "
+                   << bindings_.size() << " total";
+    }
+  }
+
+  // Add this connection to the binding.  It starts out unlocked.
+  RelayServerConnection* int_conn =
+      new RelayServerConnection(binding, ap, socket);
+  binding->AddInternalConnection(int_conn);
+  AddConnection(int_conn);
+
+  // Now that we have a connection, this other method takes over.
+  HandleStunAllocate(int_conn, request);
+}
+
+void RelayServer::HandleStun(
+    RelayServerConnection* int_conn, const char* bytes, size_t size) {
+
+  // Make sure this is a valid STUN request.
+  RelayMessage request;
+  std::string username;
+  if (!HandleStun(bytes, size, int_conn->addr_pair().source(),
+                  int_conn->socket(), &username, &request))
+    return;
+
+  // Make sure the username is the one were were expecting.
+  if (username != int_conn->binding()->username()) {
+    int_conn->SendStunError(request, 430, "Stale Credentials");
+    return;
+  }
+
+  // TODO: Check the HMAC.
+
+  // Send this request to the appropriate handler.
+  if (request.type() == STUN_SEND_REQUEST)
+    HandleStunSend(int_conn, request);
+  else if (request.type() == STUN_ALLOCATE_REQUEST)
+    HandleStunAllocate(int_conn, request);
+  else
+    int_conn->SendStunError(request, 600, "Operation Not Supported");
+}
+
+void RelayServer::HandleStunAllocate(
+    RelayServerConnection* int_conn, const StunMessage& request) {
+
+  // Create a response message that includes an address with which external
+  // clients can communicate.
+
+  RelayMessage response;
+  response.SetType(STUN_ALLOCATE_RESPONSE);
+  response.SetTransactionID(request.transaction_id());
+
+  StunByteStringAttribute* magic_cookie_attr =
+      StunAttribute::CreateByteString(cricket::STUN_ATTR_MAGIC_COOKIE);
+  magic_cookie_attr->CopyBytes(int_conn->binding()->magic_cookie().c_str(),
+                               int_conn->binding()->magic_cookie().size());
+  response.AddAttribute(magic_cookie_attr);
+
+  size_t index = rand() % external_sockets_.size();
+  rtc::SocketAddress ext_addr =
+      external_sockets_[index]->GetLocalAddress();
+
+  StunAddressAttribute* addr_attr =
+      StunAttribute::CreateAddress(STUN_ATTR_MAPPED_ADDRESS);
+  addr_attr->SetIP(ext_addr.ipaddr());
+  addr_attr->SetPort(ext_addr.port());
+  response.AddAttribute(addr_attr);
+
+  StunUInt32Attribute* res_lifetime_attr =
+      StunAttribute::CreateUInt32(STUN_ATTR_LIFETIME);
+  res_lifetime_attr->SetValue(int_conn->binding()->lifetime() / 1000);
+  response.AddAttribute(res_lifetime_attr);
+
+  // TODO: Support transport-prefs (preallocate RTCP port).
+  // TODO: Support bandwidth restrictions.
+  // TODO: Add message integrity check.
+
+  // Send a response to the caller.
+  int_conn->SendStun(response);
+}
+
+void RelayServer::HandleStunSend(
+    RelayServerConnection* int_conn, const StunMessage& request) {
+
+  const StunAddressAttribute* addr_attr =
+      request.GetAddress(STUN_ATTR_DESTINATION_ADDRESS);
+  if (!addr_attr) {
+    int_conn->SendStunError(request, 400, "Bad Request");
+    return;
+  }
+
+  const StunByteStringAttribute* data_attr =
+      request.GetByteString(STUN_ATTR_DATA);
+  if (!data_attr) {
+    int_conn->SendStunError(request, 400, "Bad Request");
+    return;
+  }
+
+  rtc::SocketAddress ext_addr(addr_attr->ipaddr(), addr_attr->port());
+  RelayServerConnection* ext_conn =
+      int_conn->binding()->GetExternalConnection(ext_addr);
+  if (!ext_conn) {
+    // Create a new connection to establish the relationship with this binding.
+    ASSERT(external_sockets_.size() == 1);
+    rtc::AsyncPacketSocket* socket = external_sockets_[0];
+    rtc::SocketAddressPair ap(ext_addr, socket->GetLocalAddress());
+    ext_conn = new RelayServerConnection(int_conn->binding(), ap, socket);
+    ext_conn->binding()->AddExternalConnection(ext_conn);
+    AddConnection(ext_conn);
+  }
+
+  // If this connection has pinged us, then allow outgoing traffic.
+  if (ext_conn->locked())
+    ext_conn->Send(data_attr->bytes(), data_attr->length());
+
+  const StunUInt32Attribute* options_attr =
+      request.GetUInt32(STUN_ATTR_OPTIONS);
+  if (options_attr && (options_attr->value() & 0x01)) {
+    int_conn->set_default_destination(ext_addr);
+    int_conn->Lock();
+
+    RelayMessage response;
+    response.SetType(STUN_SEND_RESPONSE);
+    response.SetTransactionID(request.transaction_id());
+
+    StunByteStringAttribute* magic_cookie_attr =
+        StunAttribute::CreateByteString(cricket::STUN_ATTR_MAGIC_COOKIE);
+    magic_cookie_attr->CopyBytes(int_conn->binding()->magic_cookie().c_str(),
+                                 int_conn->binding()->magic_cookie().size());
+    response.AddAttribute(magic_cookie_attr);
+
+    StunUInt32Attribute* options2_attr =
+      StunAttribute::CreateUInt32(cricket::STUN_ATTR_OPTIONS);
+    options2_attr->SetValue(0x01);
+    response.AddAttribute(options2_attr);
+
+    int_conn->SendStun(response);
+  }
+}
+
+void RelayServer::AddConnection(RelayServerConnection* conn) {
+  ASSERT(connections_.find(conn->addr_pair()) == connections_.end());
+  connections_[conn->addr_pair()] = conn;
+}
+
+void RelayServer::RemoveConnection(RelayServerConnection* conn) {
+  ConnectionMap::iterator iter = connections_.find(conn->addr_pair());
+  ASSERT(iter != connections_.end());
+  connections_.erase(iter);
+}
+
+void RelayServer::RemoveBinding(RelayServerBinding* binding) {
+  BindingMap::iterator iter = bindings_.find(binding->username());
+  ASSERT(iter != bindings_.end());
+  bindings_.erase(iter);
+
+  if (log_bindings_) {
+    LOG(LS_INFO) << "Removed binding " << binding->username() << ", "
+                 << bindings_.size() << " remaining";
+  }
+}
+
+void RelayServer::OnMessage(rtc::Message *pmsg) {
+#if ENABLE_DEBUG
+  static const uint32 kMessageAcceptConnection = 1;
+  ASSERT(pmsg->message_id == kMessageAcceptConnection);
+#endif
+  rtc::MessageData* data = pmsg->pdata;
+  rtc::AsyncSocket* socket =
+      static_cast <rtc::TypedMessageData<rtc::AsyncSocket*>*>
+      (data)->data();
+  AcceptConnection(socket);
+  delete data;
+}
+
+void RelayServer::OnTimeout(RelayServerBinding* binding) {
+  // This call will result in all of the necessary clean-up. We can't call
+  // delete here, because you can't delete an object that is signaling you.
+  thread_->Dispose(binding);
+}
+
+void RelayServer::AcceptConnection(rtc::AsyncSocket* server_socket) {
+  // Check if someone is trying to connect to us.
+  rtc::SocketAddress accept_addr;
+  rtc::AsyncSocket* accepted_socket =
+      server_socket->Accept(&accept_addr);
+  if (accepted_socket != NULL) {
+    // We had someone trying to connect, now check which protocol to
+    // use and create a packet socket.
+    ASSERT(server_sockets_[server_socket] == cricket::PROTO_TCP ||
+           server_sockets_[server_socket] == cricket::PROTO_SSLTCP);
+    if (server_sockets_[server_socket] == cricket::PROTO_SSLTCP) {
+      accepted_socket = new rtc::AsyncSSLServerSocket(accepted_socket);
+    }
+    rtc::AsyncTCPSocket* tcp_socket =
+        new rtc::AsyncTCPSocket(accepted_socket, false);
+
+    // Finally add the socket so it can start communicating with the client.
+    AddInternalSocket(tcp_socket);
+  }
+}
+
+RelayServerConnection::RelayServerConnection(
+    RelayServerBinding* binding, const rtc::SocketAddressPair& addrs,
+    rtc::AsyncPacketSocket* socket)
+  : binding_(binding), addr_pair_(addrs), socket_(socket), locked_(false) {
+  // The creation of a new connection constitutes a use of the binding.
+  binding_->NoteUsed();
+}
+
+RelayServerConnection::~RelayServerConnection() {
+  // Remove this connection from the server's map (if it exists there).
+  binding_->server()->RemoveConnection(this);
+}
+
+void RelayServerConnection::Send(const char* data, size_t size) {
+  // Note that the binding has been used again.
+  binding_->NoteUsed();
+
+  cricket::Send(socket_, data, size, addr_pair_.source());
+}
+
+void RelayServerConnection::Send(
+    const char* data, size_t size, const rtc::SocketAddress& from_addr) {
+  // If the from address is known to the client, we don't need to send it.
+  if (locked() && (from_addr == default_dest_)) {
+    Send(data, size);
+    return;
+  }
+
+  // Wrap the given data in a data-indication packet.
+
+  RelayMessage msg;
+  msg.SetType(STUN_DATA_INDICATION);
+
+  StunByteStringAttribute* magic_cookie_attr =
+      StunAttribute::CreateByteString(cricket::STUN_ATTR_MAGIC_COOKIE);
+  magic_cookie_attr->CopyBytes(binding_->magic_cookie().c_str(),
+                               binding_->magic_cookie().size());
+  msg.AddAttribute(magic_cookie_attr);
+
+  StunAddressAttribute* addr_attr =
+      StunAttribute::CreateAddress(STUN_ATTR_SOURCE_ADDRESS2);
+  addr_attr->SetIP(from_addr.ipaddr());
+  addr_attr->SetPort(from_addr.port());
+  msg.AddAttribute(addr_attr);
+
+  StunByteStringAttribute* data_attr =
+      StunAttribute::CreateByteString(STUN_ATTR_DATA);
+  ASSERT(size <= 65536);
+  data_attr->CopyBytes(data, uint16(size));
+  msg.AddAttribute(data_attr);
+
+  SendStun(msg);
+}
+
+void RelayServerConnection::SendStun(const StunMessage& msg) {
+  // Note that the binding has been used again.
+  binding_->NoteUsed();
+
+  cricket::SendStun(msg, socket_, addr_pair_.source());
+}
+
+void RelayServerConnection::SendStunError(
+      const StunMessage& request, int error_code, const char* error_desc) {
+  // An error does not indicate use.  If no legitimate use off the binding
+  // occurs, we want it to be cleaned up even if errors are still occuring.
+
+  cricket::SendStunError(
+      request, socket_, addr_pair_.source(), error_code, error_desc,
+      binding_->magic_cookie());
+}
+
+void RelayServerConnection::Lock() {
+  locked_ = true;
+}
+
+void RelayServerConnection::Unlock() {
+  locked_ = false;
+}
+
+// IDs used for posted messages:
+const uint32 MSG_LIFETIME_TIMER = 1;
+
+RelayServerBinding::RelayServerBinding(
+    RelayServer* server, const std::string& username,
+    const std::string& password, uint32 lifetime)
+  : server_(server), username_(username), password_(password),
+    lifetime_(lifetime) {
+  // For now, every connection uses the standard magic cookie value.
+  magic_cookie_.append(
+      reinterpret_cast<const char*>(TURN_MAGIC_COOKIE_VALUE),
+      sizeof(TURN_MAGIC_COOKIE_VALUE));
+
+  // Initialize the last-used time to now.
+  NoteUsed();
+
+  // Set the first timeout check.
+  server_->thread()->PostDelayed(lifetime_, this, MSG_LIFETIME_TIMER);
+}
+
+RelayServerBinding::~RelayServerBinding() {
+  // Clear the outstanding timeout check.
+  server_->thread()->Clear(this);
+
+  // Clean up all of the connections.
+  for (size_t i = 0; i < internal_connections_.size(); ++i)
+    delete internal_connections_[i];
+  for (size_t i = 0; i < external_connections_.size(); ++i)
+    delete external_connections_[i];
+
+  // Remove this binding from the server's map.
+  server_->RemoveBinding(this);
+}
+
+void RelayServerBinding::AddInternalConnection(RelayServerConnection* conn) {
+  internal_connections_.push_back(conn);
+}
+
+void RelayServerBinding::AddExternalConnection(RelayServerConnection* conn) {
+  external_connections_.push_back(conn);
+}
+
+void RelayServerBinding::NoteUsed() {
+  last_used_ = rtc::Time();
+}
+
+bool RelayServerBinding::HasMagicCookie(const char* bytes, size_t size) const {
+  if (size < 24 + magic_cookie_.size()) {
+    return false;
+  } else {
+    return memcmp(bytes + 24, magic_cookie_.c_str(), magic_cookie_.size()) == 0;
+  }
+}
+
+RelayServerConnection* RelayServerBinding::GetInternalConnection(
+    const rtc::SocketAddress& ext_addr) {
+
+  // Look for an internal connection that is locked to this address.
+  for (size_t i = 0; i < internal_connections_.size(); ++i) {
+    if (internal_connections_[i]->locked() &&
+        (ext_addr == internal_connections_[i]->default_destination()))
+      return internal_connections_[i];
+  }
+
+  // If one was not found, we send to the first connection.
+  ASSERT(internal_connections_.size() > 0);
+  return internal_connections_[0];
+}
+
+RelayServerConnection* RelayServerBinding::GetExternalConnection(
+    const rtc::SocketAddress& ext_addr) {
+  for (size_t i = 0; i < external_connections_.size(); ++i) {
+    if (ext_addr == external_connections_[i]->addr_pair().source())
+      return external_connections_[i];
+  }
+  return 0;
+}
+
+void RelayServerBinding::OnMessage(rtc::Message *pmsg) {
+  if (pmsg->message_id == MSG_LIFETIME_TIMER) {
+    ASSERT(!pmsg->pdata);
+
+    // If the lifetime timeout has been exceeded, then send a signal.
+    // Otherwise, just keep waiting.
+    if (rtc::Time() >= last_used_ + lifetime_) {
+      LOG(LS_INFO) << "Expiring binding " << username_;
+      SignalTimeout(this);
+    } else {
+      server_->thread()->PostDelayed(lifetime_, this, MSG_LIFETIME_TIMER);
+    }
+
+  } else {
+    ASSERT(false);
+  }
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/relayserver.h b/webrtc/p2p/base/relayserver.h
new file mode 100644
index 0000000..e0e45d5
--- /dev/null
+++ b/webrtc/p2p/base/relayserver.h
@@ -0,0 +1,235 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_RELAYSERVER_H_
+#define WEBRTC_P2P_BASE_RELAYSERVER_H_
+
+#include <map>
+#include <string>
+#include <vector>
+
+#include "webrtc/p2p/base/port.h"
+#include "webrtc/p2p/base/stun.h"
+#include "webrtc/base/asyncudpsocket.h"
+#include "webrtc/base/socketaddresspair.h"
+#include "webrtc/base/thread.h"
+#include "webrtc/base/timeutils.h"
+
+namespace cricket {
+
+class RelayServerBinding;
+class RelayServerConnection;
+
+// Relays traffic between connections to the server that are "bound" together.
+// All connections created with the same username/password are bound together.
+class RelayServer : public rtc::MessageHandler,
+                    public sigslot::has_slots<> {
+ public:
+  // Creates a server, which will use this thread to post messages to itself.
+  explicit RelayServer(rtc::Thread* thread);
+  ~RelayServer();
+
+  rtc::Thread* thread() { return thread_; }
+
+  // Indicates whether we will print updates of the number of bindings.
+  bool log_bindings() const { return log_bindings_; }
+  void set_log_bindings(bool log_bindings) { log_bindings_ = log_bindings; }
+
+  // Updates the set of sockets that the server uses to talk to "internal"
+  // clients.  These are clients that do the "port allocations".
+  void AddInternalSocket(rtc::AsyncPacketSocket* socket);
+  void RemoveInternalSocket(rtc::AsyncPacketSocket* socket);
+
+  // Updates the set of sockets that the server uses to talk to "external"
+  // clients.  These are the clients that do not do allocations.  They do not
+  // know that these addresses represent a relay server.
+  void AddExternalSocket(rtc::AsyncPacketSocket* socket);
+  void RemoveExternalSocket(rtc::AsyncPacketSocket* socket);
+
+  // Starts listening for connections on this sockets. When someone
+  // tries to connect, the connection will be accepted and a new
+  // internal socket will be added.
+  void AddInternalServerSocket(rtc::AsyncSocket* socket,
+                               cricket::ProtocolType proto);
+
+  // Removes this server socket from the list.
+  void RemoveInternalServerSocket(rtc::AsyncSocket* socket);
+
+  // Methods for testing and debuging.
+  int GetConnectionCount() const;
+  rtc::SocketAddressPair GetConnection(int connection) const;
+  bool HasConnection(const rtc::SocketAddress& address) const;
+
+ private:
+  typedef std::vector<rtc::AsyncPacketSocket*> SocketList;
+  typedef std::map<rtc::AsyncSocket*,
+                   cricket::ProtocolType> ServerSocketMap;
+  typedef std::map<std::string, RelayServerBinding*> BindingMap;
+  typedef std::map<rtc::SocketAddressPair,
+                   RelayServerConnection*> ConnectionMap;
+
+  rtc::Thread* thread_;
+  bool log_bindings_;
+  SocketList internal_sockets_;
+  SocketList external_sockets_;
+  SocketList removed_sockets_;
+  ServerSocketMap server_sockets_;
+  BindingMap bindings_;
+  ConnectionMap connections_;
+
+  // Called when a packet is received by the server on one of its sockets.
+  void OnInternalPacket(rtc::AsyncPacketSocket* socket,
+                        const char* bytes, size_t size,
+                        const rtc::SocketAddress& remote_addr,
+                        const rtc::PacketTime& packet_time);
+  void OnExternalPacket(rtc::AsyncPacketSocket* socket,
+                        const char* bytes, size_t size,
+                        const rtc::SocketAddress& remote_addr,
+                        const rtc::PacketTime& packet_time);
+
+  void OnReadEvent(rtc::AsyncSocket* socket);
+
+  // Processes the relevant STUN request types from the client.
+  bool HandleStun(const char* bytes, size_t size,
+                  const rtc::SocketAddress& remote_addr,
+                  rtc::AsyncPacketSocket* socket,
+                  std::string* username, StunMessage* msg);
+  void HandleStunAllocate(const char* bytes, size_t size,
+                          const rtc::SocketAddressPair& ap,
+                          rtc::AsyncPacketSocket* socket);
+  void HandleStun(RelayServerConnection* int_conn, const char* bytes,
+                  size_t size);
+  void HandleStunAllocate(RelayServerConnection* int_conn,
+                          const StunMessage& msg);
+  void HandleStunSend(RelayServerConnection* int_conn, const StunMessage& msg);
+
+  // Adds/Removes the a connection or binding.
+  void AddConnection(RelayServerConnection* conn);
+  void RemoveConnection(RelayServerConnection* conn);
+  void RemoveBinding(RelayServerBinding* binding);
+
+  // Handle messages in our worker thread.
+  void OnMessage(rtc::Message *pmsg);
+
+  // Called when the timer for checking lifetime times out.
+  void OnTimeout(RelayServerBinding* binding);
+
+  // Accept connections on this server socket.
+  void AcceptConnection(rtc::AsyncSocket* server_socket);
+
+  friend class RelayServerConnection;
+  friend class RelayServerBinding;
+};
+
+// Maintains information about a connection to the server.  Each connection is
+// part of one and only one binding.
+class RelayServerConnection {
+ public:
+  RelayServerConnection(RelayServerBinding* binding,
+                        const rtc::SocketAddressPair& addrs,
+                        rtc::AsyncPacketSocket* socket);
+  ~RelayServerConnection();
+
+  RelayServerBinding* binding() { return binding_; }
+  rtc::AsyncPacketSocket* socket() { return socket_; }
+
+  // Returns a pair where the source is the remote address and the destination
+  // is the local address.
+  const rtc::SocketAddressPair& addr_pair() { return addr_pair_; }
+
+  // Sends a packet to the connected client.  If an address is provided, then
+  // we make sure the internal client receives it, wrapping if necessary.
+  void Send(const char* data, size_t size);
+  void Send(const char* data, size_t size,
+            const rtc::SocketAddress& ext_addr);
+
+  // Sends a STUN message to the connected client with no wrapping.
+  void SendStun(const StunMessage& msg);
+  void SendStunError(const StunMessage& request, int code, const char* desc);
+
+  // A locked connection is one for which we know the intended destination of
+  // any raw packet received.
+  bool locked() const { return locked_; }
+  void Lock();
+  void Unlock();
+
+  // Records the address that raw packets should be forwarded to (for internal
+  // packets only; for external, we already know where they go).
+  const rtc::SocketAddress& default_destination() const {
+    return default_dest_;
+  }
+  void set_default_destination(const rtc::SocketAddress& addr) {
+    default_dest_ = addr;
+  }
+
+ private:
+  RelayServerBinding* binding_;
+  rtc::SocketAddressPair addr_pair_;
+  rtc::AsyncPacketSocket* socket_;
+  bool locked_;
+  rtc::SocketAddress default_dest_;
+};
+
+// Records a set of internal and external connections that we relay between,
+// or in other words, that are "bound" together.
+class RelayServerBinding : public rtc::MessageHandler {
+ public:
+  RelayServerBinding(
+      RelayServer* server, const std::string& username,
+      const std::string& password, uint32 lifetime);
+  virtual ~RelayServerBinding();
+
+  RelayServer* server() { return server_; }
+  uint32 lifetime() { return lifetime_; }
+  const std::string& username() { return username_; }
+  const std::string& password() { return password_; }
+  const std::string& magic_cookie() { return magic_cookie_; }
+
+  // Adds/Removes a connection into the binding.
+  void AddInternalConnection(RelayServerConnection* conn);
+  void AddExternalConnection(RelayServerConnection* conn);
+
+  // We keep track of the use of each binding.  If we detect that it was not
+  // used for longer than the lifetime, then we send a signal.
+  void NoteUsed();
+  sigslot::signal1<RelayServerBinding*> SignalTimeout;
+
+  // Determines whether the given packet has the magic cookie present (in the
+  // right place).
+  bool HasMagicCookie(const char* bytes, size_t size) const;
+
+  // Determines the connection to use to send packets to or from the given
+  // external address.
+  RelayServerConnection* GetInternalConnection(
+      const rtc::SocketAddress& ext_addr);
+  RelayServerConnection* GetExternalConnection(
+      const rtc::SocketAddress& ext_addr);
+
+  // MessageHandler:
+  void OnMessage(rtc::Message *pmsg);
+
+ private:
+  RelayServer* server_;
+
+  std::string username_;
+  std::string password_;
+  std::string magic_cookie_;
+
+  std::vector<RelayServerConnection*> internal_connections_;
+  std::vector<RelayServerConnection*> external_connections_;
+
+  uint32 lifetime_;
+  uint32 last_used_;
+  // TODO: bandwidth
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_RELAYSERVER_H_
diff --git a/webrtc/p2p/base/relayserver_unittest.cc b/webrtc/p2p/base/relayserver_unittest.cc
new file mode 100644
index 0000000..3349a17
--- /dev/null
+++ b/webrtc/p2p/base/relayserver_unittest.cc
@@ -0,0 +1,519 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <string>
+
+#include "webrtc/p2p/base/relayserver.h"
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/helpers.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/physicalsocketserver.h"
+#include "webrtc/base/socketaddress.h"
+#include "webrtc/base/ssladapter.h"
+#include "webrtc/base/testclient.h"
+#include "webrtc/base/thread.h"
+
+using rtc::SocketAddress;
+using namespace cricket;
+
+static const uint32 LIFETIME = 4;  // seconds
+static const SocketAddress server_int_addr("127.0.0.1", 5000);
+static const SocketAddress server_ext_addr("127.0.0.1", 5001);
+static const SocketAddress client1_addr("127.0.0.1", 6000 + (rand() % 1000));
+static const SocketAddress client2_addr("127.0.0.1", 7000 + (rand() % 1000));
+static const char* bad = "this is a completely nonsensical message whose only "
+                         "purpose is to make the parser go 'ack'.  it doesn't "
+                         "look anything like a normal stun message";
+static const char* msg1 = "spamspamspamspamspamspamspambakedbeansspam";
+static const char* msg2 = "Lobster Thermidor a Crevette with a mornay sauce...";
+
+class RelayServerTest : public testing::Test {
+ public:
+  RelayServerTest()
+      : main_(rtc::Thread::Current()), ss_(main_->socketserver()),
+        username_(rtc::CreateRandomString(12)),
+        password_(rtc::CreateRandomString(12)) {
+  }
+ protected:
+  virtual void SetUp() {
+    server_.reset(new RelayServer(main_));
+
+    server_->AddInternalSocket(
+        rtc::AsyncUDPSocket::Create(ss_, server_int_addr));
+    server_->AddExternalSocket(
+        rtc::AsyncUDPSocket::Create(ss_, server_ext_addr));
+
+    client1_.reset(new rtc::TestClient(
+        rtc::AsyncUDPSocket::Create(ss_, client1_addr)));
+    client2_.reset(new rtc::TestClient(
+        rtc::AsyncUDPSocket::Create(ss_, client2_addr)));
+  }
+
+  void Allocate() {
+    rtc::scoped_ptr<StunMessage> req(
+        CreateStunMessage(STUN_ALLOCATE_REQUEST));
+    AddUsernameAttr(req.get(), username_);
+    AddLifetimeAttr(req.get(), LIFETIME);
+    Send1(req.get());
+    delete Receive1();
+  }
+  void Bind() {
+    rtc::scoped_ptr<StunMessage> req(
+        CreateStunMessage(STUN_BINDING_REQUEST));
+    AddUsernameAttr(req.get(), username_);
+    Send2(req.get());
+    delete Receive1();
+  }
+
+  void Send1(const StunMessage* msg) {
+    rtc::ByteBuffer buf;
+    msg->Write(&buf);
+    SendRaw1(buf.Data(), static_cast<int>(buf.Length()));
+  }
+  void Send2(const StunMessage* msg) {
+    rtc::ByteBuffer buf;
+    msg->Write(&buf);
+    SendRaw2(buf.Data(), static_cast<int>(buf.Length()));
+  }
+  void SendRaw1(const char* data, int len) {
+    return Send(client1_.get(), data, len, server_int_addr);
+  }
+  void SendRaw2(const char* data, int len) {
+    return Send(client2_.get(), data, len, server_ext_addr);
+  }
+  void Send(rtc::TestClient* client, const char* data,
+            int len, const SocketAddress& addr) {
+    client->SendTo(data, len, addr);
+  }
+
+  StunMessage* Receive1() {
+    return Receive(client1_.get());
+  }
+  StunMessage* Receive2() {
+    return Receive(client2_.get());
+  }
+  std::string ReceiveRaw1() {
+    return ReceiveRaw(client1_.get());
+  }
+  std::string ReceiveRaw2() {
+    return ReceiveRaw(client2_.get());
+  }
+  StunMessage* Receive(rtc::TestClient* client) {
+    StunMessage* msg = NULL;
+    rtc::TestClient::Packet* packet = client->NextPacket();
+    if (packet) {
+      rtc::ByteBuffer buf(packet->buf, packet->size);
+      msg = new RelayMessage();
+      msg->Read(&buf);
+      delete packet;
+    }
+    return msg;
+  }
+  std::string ReceiveRaw(rtc::TestClient* client) {
+    std::string raw;
+    rtc::TestClient::Packet* packet = client->NextPacket();
+    if (packet) {
+      raw = std::string(packet->buf, packet->size);
+      delete packet;
+    }
+    return raw;
+  }
+
+  static StunMessage* CreateStunMessage(int type) {
+    StunMessage* msg = new RelayMessage();
+    msg->SetType(type);
+    msg->SetTransactionID(
+        rtc::CreateRandomString(kStunTransactionIdLength));
+    return msg;
+  }
+  static void AddMagicCookieAttr(StunMessage* msg) {
+    StunByteStringAttribute* attr =
+        StunAttribute::CreateByteString(STUN_ATTR_MAGIC_COOKIE);
+    attr->CopyBytes(TURN_MAGIC_COOKIE_VALUE, sizeof(TURN_MAGIC_COOKIE_VALUE));
+    msg->AddAttribute(attr);
+  }
+  static void AddUsernameAttr(StunMessage* msg, const std::string& val) {
+    StunByteStringAttribute* attr =
+        StunAttribute::CreateByteString(STUN_ATTR_USERNAME);
+    attr->CopyBytes(val.c_str(), val.size());
+    msg->AddAttribute(attr);
+  }
+  static void AddLifetimeAttr(StunMessage* msg, int val) {
+    StunUInt32Attribute* attr =
+        StunAttribute::CreateUInt32(STUN_ATTR_LIFETIME);
+    attr->SetValue(val);
+    msg->AddAttribute(attr);
+  }
+  static void AddDestinationAttr(StunMessage* msg, const SocketAddress& addr) {
+    StunAddressAttribute* attr =
+        StunAttribute::CreateAddress(STUN_ATTR_DESTINATION_ADDRESS);
+    attr->SetIP(addr.ipaddr());
+    attr->SetPort(addr.port());
+    msg->AddAttribute(attr);
+  }
+
+  rtc::Thread* main_;
+  rtc::SocketServer* ss_;
+  rtc::scoped_ptr<RelayServer> server_;
+  rtc::scoped_ptr<rtc::TestClient> client1_;
+  rtc::scoped_ptr<rtc::TestClient> client2_;
+  std::string username_;
+  std::string password_;
+};
+
+// Send a complete nonsense message and verify that it is eaten.
+TEST_F(RelayServerTest, TestBadRequest) {
+  rtc::scoped_ptr<StunMessage> res;
+
+  SendRaw1(bad, static_cast<int>(strlen(bad)));
+  res.reset(Receive1());
+
+  ASSERT_TRUE(!res);
+}
+
+// Send an allocate request without a username and verify it is rejected.
+TEST_F(RelayServerTest, TestAllocateNoUsername) {
+  rtc::scoped_ptr<StunMessage> req(
+      CreateStunMessage(STUN_ALLOCATE_REQUEST)), res;
+
+  Send1(req.get());
+  res.reset(Receive1());
+
+  ASSERT_TRUE(res);
+  EXPECT_EQ(STUN_ALLOCATE_ERROR_RESPONSE, res->type());
+  EXPECT_EQ(req->transaction_id(), res->transaction_id());
+
+  const StunErrorCodeAttribute* err = res->GetErrorCode();
+  ASSERT_TRUE(err != NULL);
+  EXPECT_EQ(4, err->eclass());
+  EXPECT_EQ(32, err->number());
+  EXPECT_EQ("Missing Username", err->reason());
+}
+
+// Send a binding request and verify that it is rejected.
+TEST_F(RelayServerTest, TestBindingRequest) {
+  rtc::scoped_ptr<StunMessage> req(
+      CreateStunMessage(STUN_BINDING_REQUEST)), res;
+  AddUsernameAttr(req.get(), username_);
+
+  Send1(req.get());
+  res.reset(Receive1());
+
+  ASSERT_TRUE(res);
+  EXPECT_EQ(STUN_BINDING_ERROR_RESPONSE, res->type());
+  EXPECT_EQ(req->transaction_id(), res->transaction_id());
+
+  const StunErrorCodeAttribute* err = res->GetErrorCode();
+  ASSERT_TRUE(err != NULL);
+  EXPECT_EQ(6, err->eclass());
+  EXPECT_EQ(0, err->number());
+  EXPECT_EQ("Operation Not Supported", err->reason());
+}
+
+// Send an allocate request and verify that it is accepted.
+TEST_F(RelayServerTest, TestAllocate) {
+  rtc::scoped_ptr<StunMessage> req(
+      CreateStunMessage(STUN_ALLOCATE_REQUEST)), res;
+  AddUsernameAttr(req.get(), username_);
+  AddLifetimeAttr(req.get(), LIFETIME);
+
+  Send1(req.get());
+  res.reset(Receive1());
+
+  ASSERT_TRUE(res);
+  EXPECT_EQ(STUN_ALLOCATE_RESPONSE, res->type());
+  EXPECT_EQ(req->transaction_id(), res->transaction_id());
+
+  const StunAddressAttribute* mapped_addr =
+      res->GetAddress(STUN_ATTR_MAPPED_ADDRESS);
+  ASSERT_TRUE(mapped_addr != NULL);
+  EXPECT_EQ(1, mapped_addr->family());
+  EXPECT_EQ(server_ext_addr.port(), mapped_addr->port());
+  EXPECT_EQ(server_ext_addr.ipaddr(), mapped_addr->ipaddr());
+
+  const StunUInt32Attribute* res_lifetime_attr =
+      res->GetUInt32(STUN_ATTR_LIFETIME);
+  ASSERT_TRUE(res_lifetime_attr != NULL);
+  EXPECT_EQ(LIFETIME, res_lifetime_attr->value());
+}
+
+// Send a second allocate request and verify that it is also accepted, though
+// the lifetime should be ignored.
+TEST_F(RelayServerTest, TestReallocate) {
+  Allocate();
+
+  rtc::scoped_ptr<StunMessage> req(
+      CreateStunMessage(STUN_ALLOCATE_REQUEST)), res;
+  AddMagicCookieAttr(req.get());
+  AddUsernameAttr(req.get(), username_);
+
+  Send1(req.get());
+  res.reset(Receive1());
+
+  ASSERT_TRUE(res);
+  EXPECT_EQ(STUN_ALLOCATE_RESPONSE, res->type());
+  EXPECT_EQ(req->transaction_id(), res->transaction_id());
+
+  const StunAddressAttribute* mapped_addr =
+      res->GetAddress(STUN_ATTR_MAPPED_ADDRESS);
+  ASSERT_TRUE(mapped_addr != NULL);
+  EXPECT_EQ(1, mapped_addr->family());
+  EXPECT_EQ(server_ext_addr.port(), mapped_addr->port());
+  EXPECT_EQ(server_ext_addr.ipaddr(), mapped_addr->ipaddr());
+
+  const StunUInt32Attribute* lifetime_attr =
+      res->GetUInt32(STUN_ATTR_LIFETIME);
+  ASSERT_TRUE(lifetime_attr != NULL);
+  EXPECT_EQ(LIFETIME, lifetime_attr->value());
+}
+
+// Send a request from another client and see that it arrives at the first
+// client in the binding.
+TEST_F(RelayServerTest, TestRemoteBind) {
+  Allocate();
+
+  rtc::scoped_ptr<StunMessage> req(
+      CreateStunMessage(STUN_BINDING_REQUEST)), res;
+  AddUsernameAttr(req.get(), username_);
+
+  Send2(req.get());
+  res.reset(Receive1());
+
+  ASSERT_TRUE(res);
+  EXPECT_EQ(STUN_DATA_INDICATION, res->type());
+
+  const StunByteStringAttribute* recv_data =
+      res->GetByteString(STUN_ATTR_DATA);
+  ASSERT_TRUE(recv_data != NULL);
+
+  rtc::ByteBuffer buf(recv_data->bytes(), recv_data->length());
+  rtc::scoped_ptr<StunMessage> res2(new StunMessage());
+  EXPECT_TRUE(res2->Read(&buf));
+  EXPECT_EQ(STUN_BINDING_REQUEST, res2->type());
+  EXPECT_EQ(req->transaction_id(), res2->transaction_id());
+
+  const StunAddressAttribute* src_addr =
+      res->GetAddress(STUN_ATTR_SOURCE_ADDRESS2);
+  ASSERT_TRUE(src_addr != NULL);
+  EXPECT_EQ(1, src_addr->family());
+  EXPECT_EQ(client2_addr.ipaddr(), src_addr->ipaddr());
+  EXPECT_EQ(client2_addr.port(), src_addr->port());
+
+  EXPECT_TRUE(Receive2() == NULL);
+}
+
+// Send a complete nonsense message to the established connection and verify
+// that it is dropped by the server.
+TEST_F(RelayServerTest, TestRemoteBadRequest) {
+  Allocate();
+  Bind();
+
+  SendRaw1(bad, static_cast<int>(strlen(bad)));
+  EXPECT_TRUE(Receive1() == NULL);
+  EXPECT_TRUE(Receive2() == NULL);
+}
+
+// Send a send request without a username and verify it is rejected.
+TEST_F(RelayServerTest, TestSendRequestMissingUsername) {
+  Allocate();
+  Bind();
+
+  rtc::scoped_ptr<StunMessage> req(
+      CreateStunMessage(STUN_SEND_REQUEST)), res;
+  AddMagicCookieAttr(req.get());
+
+  Send1(req.get());
+  res.reset(Receive1());
+
+  ASSERT_TRUE(res);
+  EXPECT_EQ(STUN_SEND_ERROR_RESPONSE, res->type());
+  EXPECT_EQ(req->transaction_id(), res->transaction_id());
+
+  const StunErrorCodeAttribute* err = res->GetErrorCode();
+  ASSERT_TRUE(err != NULL);
+  EXPECT_EQ(4, err->eclass());
+  EXPECT_EQ(32, err->number());
+  EXPECT_EQ("Missing Username", err->reason());
+}
+
+// Send a send request with the wrong username and verify it is rejected.
+TEST_F(RelayServerTest, TestSendRequestBadUsername) {
+  Allocate();
+  Bind();
+
+  rtc::scoped_ptr<StunMessage> req(
+      CreateStunMessage(STUN_SEND_REQUEST)), res;
+  AddMagicCookieAttr(req.get());
+  AddUsernameAttr(req.get(), "foobarbizbaz");
+
+  Send1(req.get());
+  res.reset(Receive1());
+
+  ASSERT_TRUE(res);
+  EXPECT_EQ(STUN_SEND_ERROR_RESPONSE, res->type());
+  EXPECT_EQ(req->transaction_id(), res->transaction_id());
+
+  const StunErrorCodeAttribute* err = res->GetErrorCode();
+  ASSERT_TRUE(err != NULL);
+  EXPECT_EQ(4, err->eclass());
+  EXPECT_EQ(30, err->number());
+  EXPECT_EQ("Stale Credentials", err->reason());
+}
+
+// Send a send request without a destination address and verify that it is
+// rejected.
+TEST_F(RelayServerTest, TestSendRequestNoDestinationAddress) {
+  Allocate();
+  Bind();
+
+  rtc::scoped_ptr<StunMessage> req(
+      CreateStunMessage(STUN_SEND_REQUEST)), res;
+  AddMagicCookieAttr(req.get());
+  AddUsernameAttr(req.get(), username_);
+
+  Send1(req.get());
+  res.reset(Receive1());
+
+  ASSERT_TRUE(res);
+  EXPECT_EQ(STUN_SEND_ERROR_RESPONSE, res->type());
+  EXPECT_EQ(req->transaction_id(), res->transaction_id());
+
+  const StunErrorCodeAttribute* err = res->GetErrorCode();
+  ASSERT_TRUE(err != NULL);
+  EXPECT_EQ(4, err->eclass());
+  EXPECT_EQ(0, err->number());
+  EXPECT_EQ("Bad Request", err->reason());
+}
+
+// Send a send request without data and verify that it is rejected.
+TEST_F(RelayServerTest, TestSendRequestNoData) {
+  Allocate();
+  Bind();
+
+  rtc::scoped_ptr<StunMessage> req(
+      CreateStunMessage(STUN_SEND_REQUEST)), res;
+  AddMagicCookieAttr(req.get());
+  AddUsernameAttr(req.get(), username_);
+  AddDestinationAttr(req.get(), client2_addr);
+
+  Send1(req.get());
+  res.reset(Receive1());
+
+  ASSERT_TRUE(res);
+  EXPECT_EQ(STUN_SEND_ERROR_RESPONSE, res->type());
+  EXPECT_EQ(req->transaction_id(), res->transaction_id());
+
+  const StunErrorCodeAttribute* err = res->GetErrorCode();
+  ASSERT_TRUE(err != NULL);
+  EXPECT_EQ(4, err->eclass());
+  EXPECT_EQ(00, err->number());
+  EXPECT_EQ("Bad Request", err->reason());
+}
+
+// Send a binding request after an allocate and verify that it is rejected.
+TEST_F(RelayServerTest, TestSendRequestWrongType) {
+  Allocate();
+  Bind();
+
+  rtc::scoped_ptr<StunMessage> req(
+      CreateStunMessage(STUN_BINDING_REQUEST)), res;
+  AddMagicCookieAttr(req.get());
+  AddUsernameAttr(req.get(), username_);
+
+  Send1(req.get());
+  res.reset(Receive1());
+
+  ASSERT_TRUE(res);
+  EXPECT_EQ(STUN_BINDING_ERROR_RESPONSE, res->type());
+  EXPECT_EQ(req->transaction_id(), res->transaction_id());
+
+  const StunErrorCodeAttribute* err = res->GetErrorCode();
+  ASSERT_TRUE(err != NULL);
+  EXPECT_EQ(6, err->eclass());
+  EXPECT_EQ(0, err->number());
+  EXPECT_EQ("Operation Not Supported", err->reason());
+}
+
+// Verify that we can send traffic back and forth between the clients after a
+// successful allocate and bind.
+TEST_F(RelayServerTest, TestSendRaw) {
+  Allocate();
+  Bind();
+
+  for (int i = 0; i < 10; i++) {
+    rtc::scoped_ptr<StunMessage> req(
+        CreateStunMessage(STUN_SEND_REQUEST)), res;
+    AddMagicCookieAttr(req.get());
+    AddUsernameAttr(req.get(), username_);
+    AddDestinationAttr(req.get(), client2_addr);
+
+    StunByteStringAttribute* send_data =
+        StunAttribute::CreateByteString(STUN_ATTR_DATA);
+    send_data->CopyBytes(msg1);
+    req->AddAttribute(send_data);
+
+    Send1(req.get());
+    EXPECT_EQ(msg1, ReceiveRaw2());
+    SendRaw2(msg2, static_cast<int>(strlen(msg2)));
+    res.reset(Receive1());
+
+    ASSERT_TRUE(res);
+    EXPECT_EQ(STUN_DATA_INDICATION, res->type());
+
+    const StunAddressAttribute* src_addr =
+        res->GetAddress(STUN_ATTR_SOURCE_ADDRESS2);
+    ASSERT_TRUE(src_addr != NULL);
+    EXPECT_EQ(1, src_addr->family());
+    EXPECT_EQ(client2_addr.ipaddr(), src_addr->ipaddr());
+    EXPECT_EQ(client2_addr.port(), src_addr->port());
+
+    const StunByteStringAttribute* recv_data =
+        res->GetByteString(STUN_ATTR_DATA);
+    ASSERT_TRUE(recv_data != NULL);
+    EXPECT_EQ(strlen(msg2), recv_data->length());
+    EXPECT_EQ(0, memcmp(msg2, recv_data->bytes(), recv_data->length()));
+  }
+}
+
+// Verify that a binding expires properly, and rejects send requests.
+TEST_F(RelayServerTest, TestExpiration) {
+  Allocate();
+  Bind();
+
+  // Wait twice the lifetime to make sure the server has expired the binding.
+  rtc::Thread::Current()->ProcessMessages((LIFETIME * 2) * 1000);
+
+  rtc::scoped_ptr<StunMessage> req(
+      CreateStunMessage(STUN_SEND_REQUEST)), res;
+  AddMagicCookieAttr(req.get());
+  AddUsernameAttr(req.get(), username_);
+  AddDestinationAttr(req.get(), client2_addr);
+
+  StunByteStringAttribute* data_attr =
+      StunAttribute::CreateByteString(STUN_ATTR_DATA);
+  data_attr->CopyBytes(msg1);
+  req->AddAttribute(data_attr);
+
+  Send1(req.get());
+  res.reset(Receive1());
+
+  ASSERT_TRUE(res.get() != NULL);
+  EXPECT_EQ(STUN_SEND_ERROR_RESPONSE, res->type());
+
+  const StunErrorCodeAttribute* err = res->GetErrorCode();
+  ASSERT_TRUE(err != NULL);
+  EXPECT_EQ(6, err->eclass());
+  EXPECT_EQ(0, err->number());
+  EXPECT_EQ("Operation Not Supported", err->reason());
+
+  // Also verify that traffic from the external client is ignored.
+  SendRaw2(msg2, static_cast<int>(strlen(msg2)));
+  EXPECT_TRUE(ReceiveRaw1().empty());
+}
diff --git a/webrtc/p2p/base/session.cc b/webrtc/p2p/base/session.cc
new file mode 100644
index 0000000..9749b14
--- /dev/null
+++ b/webrtc/p2p/base/session.cc
@@ -0,0 +1,1760 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/session.h"
+
+#include "webrtc/p2p/base/dtlstransport.h"
+#include "webrtc/p2p/base/p2ptransport.h"
+#include "webrtc/p2p/base/sessionclient.h"
+#include "webrtc/p2p/base/transport.h"
+#include "webrtc/p2p/base/transportchannelproxy.h"
+#include "webrtc/p2p/base/transportinfo.h"
+#include "webrtc/libjingle/xmpp/constants.h"
+#include "webrtc/libjingle/xmpp/jid.h"
+#include "webrtc/base/bind.h"
+#include "webrtc/base/common.h"
+#include "webrtc/base/helpers.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/sslstreamadapter.h"
+
+#include "webrtc/p2p/base/constants.h"
+
+namespace cricket {
+
+using rtc::Bind;
+
+bool BadMessage(const buzz::QName type,
+                const std::string& text,
+                MessageError* err) {
+  err->SetType(type);
+  err->SetText(text);
+  return false;
+}
+
+TransportProxy::~TransportProxy() {
+  for (ChannelMap::iterator iter = channels_.begin();
+       iter != channels_.end(); ++iter) {
+    iter->second->SignalDestroyed(iter->second);
+    delete iter->second;
+  }
+}
+
+const std::string& TransportProxy::type() const {
+  return transport_->get()->type();
+}
+
+TransportChannel* TransportProxy::GetChannel(int component) {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  return GetChannelProxy(component);
+}
+
+TransportChannel* TransportProxy::CreateChannel(
+    const std::string& name, int component) {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  ASSERT(GetChannel(component) == NULL);
+  ASSERT(!transport_->get()->HasChannel(component));
+
+  // We always create a proxy in case we need to change out the transport later.
+  TransportChannelProxy* channel =
+      new TransportChannelProxy(content_name(), name, component);
+  channels_[component] = channel;
+
+  // If we're already negotiated, create an impl and hook it up to the proxy
+  // channel. If we're connecting, create an impl but don't hook it up yet.
+  if (negotiated_) {
+    SetupChannelProxy_w(component, channel);
+  } else if (connecting_) {
+    GetOrCreateChannelProxyImpl_w(component);
+  }
+  return channel;
+}
+
+bool TransportProxy::HasChannel(int component) {
+  return transport_->get()->HasChannel(component);
+}
+
+void TransportProxy::DestroyChannel(int component) {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  TransportChannel* channel = GetChannel(component);
+  if (channel) {
+    // If the state of TransportProxy is not NEGOTIATED
+    // then TransportChannelProxy and its impl are not
+    // connected. Both must be connected before
+    // deletion.
+    if (!negotiated_) {
+      SetupChannelProxy_w(component, GetChannelProxy(component));
+    }
+
+    channels_.erase(component);
+    channel->SignalDestroyed(channel);
+    delete channel;
+  }
+}
+
+void TransportProxy::ConnectChannels() {
+  if (!connecting_) {
+    if (!negotiated_) {
+      for (ChannelMap::iterator iter = channels_.begin();
+           iter != channels_.end(); ++iter) {
+        GetOrCreateChannelProxyImpl(iter->first);
+      }
+    }
+    connecting_ = true;
+  }
+  // TODO(juberti): Right now Transport::ConnectChannels doesn't work if we
+  // don't have any channels yet, so we need to allow this method to be called
+  // multiple times. Once we fix Transport, we can move this call inside the
+  // if (!connecting_) block.
+  transport_->get()->ConnectChannels();
+}
+
+void TransportProxy::CompleteNegotiation() {
+  if (!negotiated_) {
+    for (ChannelMap::iterator iter = channels_.begin();
+         iter != channels_.end(); ++iter) {
+      SetupChannelProxy(iter->first, iter->second);
+    }
+    negotiated_ = true;
+  }
+}
+
+void TransportProxy::AddSentCandidates(const Candidates& candidates) {
+  for (Candidates::const_iterator cand = candidates.begin();
+       cand != candidates.end(); ++cand) {
+    sent_candidates_.push_back(*cand);
+  }
+}
+
+void TransportProxy::AddUnsentCandidates(const Candidates& candidates) {
+  for (Candidates::const_iterator cand = candidates.begin();
+       cand != candidates.end(); ++cand) {
+    unsent_candidates_.push_back(*cand);
+  }
+}
+
+bool TransportProxy::GetChannelNameFromComponent(
+    int component, std::string* channel_name) const {
+  const TransportChannelProxy* channel = GetChannelProxy(component);
+  if (channel == NULL) {
+    return false;
+  }
+
+  *channel_name = channel->name();
+  return true;
+}
+
+bool TransportProxy::GetComponentFromChannelName(
+    const std::string& channel_name, int* component) const {
+  const TransportChannelProxy* channel = GetChannelProxyByName(channel_name);
+  if (channel == NULL) {
+    return false;
+  }
+
+  *component = channel->component();
+  return true;
+}
+
+TransportChannelProxy* TransportProxy::GetChannelProxy(int component) const {
+  ChannelMap::const_iterator iter = channels_.find(component);
+  return (iter != channels_.end()) ? iter->second : NULL;
+}
+
+TransportChannelProxy* TransportProxy::GetChannelProxyByName(
+    const std::string& name) const {
+  for (ChannelMap::const_iterator iter = channels_.begin();
+       iter != channels_.end();
+       ++iter) {
+    if (iter->second->name() == name) {
+      return iter->second;
+    }
+  }
+  return NULL;
+}
+
+TransportChannelImpl* TransportProxy::GetOrCreateChannelProxyImpl(
+    int component) {
+  return worker_thread_->Invoke<TransportChannelImpl*>(Bind(
+      &TransportProxy::GetOrCreateChannelProxyImpl_w, this, component));
+}
+
+TransportChannelImpl* TransportProxy::GetOrCreateChannelProxyImpl_w(
+    int component) {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  TransportChannelImpl* impl = transport_->get()->GetChannel(component);
+  if (impl == NULL) {
+    impl = transport_->get()->CreateChannel(component);
+  }
+  return impl;
+}
+
+void TransportProxy::SetupChannelProxy(
+    int component, TransportChannelProxy* transproxy) {
+  worker_thread_->Invoke<void>(Bind(
+      &TransportProxy::SetupChannelProxy_w, this, component, transproxy));
+}
+
+void TransportProxy::SetupChannelProxy_w(
+    int component, TransportChannelProxy* transproxy) {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  TransportChannelImpl* impl = GetOrCreateChannelProxyImpl(component);
+  ASSERT(impl != NULL);
+  transproxy->SetImplementation(impl);
+}
+
+void TransportProxy::ReplaceChannelProxyImpl(TransportChannelProxy* proxy,
+                                             TransportChannelImpl* impl) {
+  worker_thread_->Invoke<void>(Bind(
+      &TransportProxy::ReplaceChannelProxyImpl_w, this, proxy, impl));
+}
+
+void TransportProxy::ReplaceChannelProxyImpl_w(TransportChannelProxy* proxy,
+                                               TransportChannelImpl* impl) {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  ASSERT(proxy != NULL);
+  proxy->SetImplementation(impl);
+}
+
+// This function muxes |this| onto |target| by repointing |this| at
+// |target|'s transport and setting our TransportChannelProxies
+// to point to |target|'s underlying implementations.
+bool TransportProxy::SetupMux(TransportProxy* target) {
+  // Bail out if there's nothing to do.
+  if (transport_ == target->transport_) {
+    return true;
+  }
+
+  // Run through all channels and remove any non-rtp transport channels before
+  // setting target transport channels.
+  for (ChannelMap::const_iterator iter = channels_.begin();
+       iter != channels_.end(); ++iter) {
+    if (!target->transport_->get()->HasChannel(iter->first)) {
+      // Remove if channel doesn't exist in |transport_|.
+      ReplaceChannelProxyImpl(iter->second, NULL);
+    } else {
+      // Replace the impl for all the TransportProxyChannels with the channels
+      // from |target|'s transport. Fail if there's not an exact match.
+      ReplaceChannelProxyImpl(
+          iter->second, target->transport_->get()->CreateChannel(iter->first));
+    }
+  }
+
+  // Now replace our transport. Must happen afterwards because
+  // it deletes all impls as a side effect.
+  transport_ = target->transport_;
+  transport_->get()->SignalCandidatesReady.connect(
+      this, &TransportProxy::OnTransportCandidatesReady);
+  set_candidates_allocated(target->candidates_allocated());
+  return true;
+}
+
+void TransportProxy::SetIceRole(IceRole role) {
+  transport_->get()->SetIceRole(role);
+}
+
+bool TransportProxy::SetLocalTransportDescription(
+    const TransportDescription& description,
+    ContentAction action,
+    std::string* error_desc) {
+  // If this is an answer, finalize the negotiation.
+  if (action == CA_ANSWER) {
+    CompleteNegotiation();
+  }
+  bool result = transport_->get()->SetLocalTransportDescription(description,
+                                                                action,
+                                                                error_desc);
+  if (result)
+    local_description_set_ = true;
+  return result;
+}
+
+bool TransportProxy::SetRemoteTransportDescription(
+    const TransportDescription& description,
+    ContentAction action,
+    std::string* error_desc) {
+  // If this is an answer, finalize the negotiation.
+  if (action == CA_ANSWER) {
+    CompleteNegotiation();
+  }
+  bool result = transport_->get()->SetRemoteTransportDescription(description,
+                                                                 action,
+                                                                 error_desc);
+  if (result)
+    remote_description_set_ = true;
+  return result;
+}
+
+void TransportProxy::OnSignalingReady() {
+  // If we're starting a new allocation sequence, reset our state.
+  set_candidates_allocated(false);
+  transport_->get()->OnSignalingReady();
+}
+
+bool TransportProxy::OnRemoteCandidates(const Candidates& candidates,
+                                        std::string* error) {
+  // Ensure the transport is negotiated before handling candidates.
+  // TODO(juberti): Remove this once everybody calls SetLocalTD.
+  CompleteNegotiation();
+
+  // Verify each candidate before passing down to transport layer.
+  for (Candidates::const_iterator cand = candidates.begin();
+       cand != candidates.end(); ++cand) {
+    if (!transport_->get()->VerifyCandidate(*cand, error))
+      return false;
+    if (!HasChannel(cand->component())) {
+      *error = "Candidate has unknown component: " + cand->ToString() +
+               " for content: " + content_name_;
+      return false;
+    }
+  }
+  transport_->get()->OnRemoteCandidates(candidates);
+  return true;
+}
+
+void TransportProxy::SetIdentity(
+    rtc::SSLIdentity* identity) {
+  transport_->get()->SetIdentity(identity);
+}
+
+std::string BaseSession::StateToString(State state) {
+  switch (state) {
+    case Session::STATE_INIT:
+      return "STATE_INIT";
+    case Session::STATE_SENTINITIATE:
+      return "STATE_SENTINITIATE";
+    case Session::STATE_RECEIVEDINITIATE:
+      return "STATE_RECEIVEDINITIATE";
+    case Session::STATE_SENTPRACCEPT:
+      return "STATE_SENTPRACCEPT";
+    case Session::STATE_SENTACCEPT:
+      return "STATE_SENTACCEPT";
+    case Session::STATE_RECEIVEDPRACCEPT:
+      return "STATE_RECEIVEDPRACCEPT";
+    case Session::STATE_RECEIVEDACCEPT:
+      return "STATE_RECEIVEDACCEPT";
+    case Session::STATE_SENTMODIFY:
+      return "STATE_SENTMODIFY";
+    case Session::STATE_RECEIVEDMODIFY:
+      return "STATE_RECEIVEDMODIFY";
+    case Session::STATE_SENTREJECT:
+      return "STATE_SENTREJECT";
+    case Session::STATE_RECEIVEDREJECT:
+      return "STATE_RECEIVEDREJECT";
+    case Session::STATE_SENTREDIRECT:
+      return "STATE_SENTREDIRECT";
+    case Session::STATE_SENTTERMINATE:
+      return "STATE_SENTTERMINATE";
+    case Session::STATE_RECEIVEDTERMINATE:
+      return "STATE_RECEIVEDTERMINATE";
+    case Session::STATE_INPROGRESS:
+      return "STATE_INPROGRESS";
+    case Session::STATE_DEINIT:
+      return "STATE_DEINIT";
+    default:
+      break;
+  }
+  return "STATE_" + rtc::ToString(state);
+}
+
+BaseSession::BaseSession(rtc::Thread* signaling_thread,
+                         rtc::Thread* worker_thread,
+                         PortAllocator* port_allocator,
+                         const std::string& sid,
+                         const std::string& content_type,
+                         bool initiator)
+    : state_(STATE_INIT),
+      error_(ERROR_NONE),
+      signaling_thread_(signaling_thread),
+      worker_thread_(worker_thread),
+      port_allocator_(port_allocator),
+      sid_(sid),
+      content_type_(content_type),
+      transport_type_(NS_GINGLE_P2P),
+      initiator_(initiator),
+      identity_(NULL),
+      ice_tiebreaker_(rtc::CreateRandomId64()),
+      role_switch_(false) {
+  ASSERT(signaling_thread->IsCurrent());
+}
+
+BaseSession::~BaseSession() {
+  ASSERT(signaling_thread()->IsCurrent());
+
+  ASSERT(state_ != STATE_DEINIT);
+  LogState(state_, STATE_DEINIT);
+  state_ = STATE_DEINIT;
+  SignalState(this, state_);
+
+  for (TransportMap::iterator iter = transports_.begin();
+       iter != transports_.end(); ++iter) {
+    delete iter->second;
+  }
+}
+
+const SessionDescription* BaseSession::local_description() const {
+  // TODO(tommi): Assert on thread correctness.
+  return local_description_.get();
+}
+
+const SessionDescription* BaseSession::remote_description() const {
+  // TODO(tommi): Assert on thread correctness.
+  return remote_description_.get();
+}
+
+SessionDescription* BaseSession::remote_description() {
+  // TODO(tommi): Assert on thread correctness.
+  return remote_description_.get();
+}
+
+void BaseSession::set_local_description(const SessionDescription* sdesc) {
+  // TODO(tommi): Assert on thread correctness.
+  if (sdesc != local_description_.get())
+    local_description_.reset(sdesc);
+}
+
+void BaseSession::set_remote_description(SessionDescription* sdesc) {
+  // TODO(tommi): Assert on thread correctness.
+  if (sdesc != remote_description_)
+    remote_description_.reset(sdesc);
+}
+
+const SessionDescription* BaseSession::initiator_description() const {
+  // TODO(tommi): Assert on thread correctness.
+  return initiator_ ? local_description_.get() : remote_description_.get();
+}
+
+bool BaseSession::SetIdentity(rtc::SSLIdentity* identity) {
+  if (identity_)
+    return false;
+  identity_ = identity;
+  for (TransportMap::iterator iter = transports_.begin();
+       iter != transports_.end(); ++iter) {
+    iter->second->SetIdentity(identity_);
+  }
+  return true;
+}
+
+bool BaseSession::PushdownTransportDescription(ContentSource source,
+                                               ContentAction action,
+                                               std::string* error_desc) {
+  if (source == CS_LOCAL) {
+    return PushdownLocalTransportDescription(local_description(),
+                                             action,
+                                             error_desc);
+  }
+  return PushdownRemoteTransportDescription(remote_description(),
+                                            action,
+                                            error_desc);
+}
+
+bool BaseSession::PushdownLocalTransportDescription(
+    const SessionDescription* sdesc,
+    ContentAction action,
+    std::string* error_desc) {
+  // Update the Transports with the right information, and trigger them to
+  // start connecting.
+  for (TransportMap::iterator iter = transports_.begin();
+       iter != transports_.end(); ++iter) {
+    // If no transport info was in this session description, ret == false
+    // and we just skip this one.
+    TransportDescription tdesc;
+    bool ret = GetTransportDescription(
+        sdesc, iter->second->content_name(), &tdesc);
+    if (ret) {
+      if (!iter->second->SetLocalTransportDescription(tdesc, action,
+                                                      error_desc)) {
+        return false;
+      }
+
+      iter->second->ConnectChannels();
+    }
+  }
+
+  return true;
+}
+
+bool BaseSession::PushdownRemoteTransportDescription(
+    const SessionDescription* sdesc,
+    ContentAction action,
+    std::string* error_desc) {
+  // Update the Transports with the right information.
+  for (TransportMap::iterator iter = transports_.begin();
+       iter != transports_.end(); ++iter) {
+    TransportDescription tdesc;
+
+    // If no transport info was in this session description, ret == false
+    // and we just skip this one.
+    bool ret = GetTransportDescription(
+        sdesc, iter->second->content_name(), &tdesc);
+    if (ret) {
+      if (!iter->second->SetRemoteTransportDescription(tdesc, action,
+                                                       error_desc)) {
+        return false;
+      }
+    }
+  }
+
+  return true;
+}
+
+TransportChannel* BaseSession::CreateChannel(const std::string& content_name,
+                                             const std::string& channel_name,
+                                             int component) {
+  // We create the proxy "on demand" here because we need to support
+  // creating channels at any time, even before we send or receive
+  // initiate messages, which is before we create the transports.
+  TransportProxy* transproxy = GetOrCreateTransportProxy(content_name);
+  return transproxy->CreateChannel(channel_name, component);
+}
+
+TransportChannel* BaseSession::GetChannel(const std::string& content_name,
+                                          int component) {
+  TransportProxy* transproxy = GetTransportProxy(content_name);
+  if (transproxy == NULL)
+    return NULL;
+
+  return transproxy->GetChannel(component);
+}
+
+void BaseSession::DestroyChannel(const std::string& content_name,
+                                 int component) {
+  TransportProxy* transproxy = GetTransportProxy(content_name);
+  ASSERT(transproxy != NULL);
+  transproxy->DestroyChannel(component);
+}
+
+TransportProxy* BaseSession::GetOrCreateTransportProxy(
+    const std::string& content_name) {
+  TransportProxy* transproxy = GetTransportProxy(content_name);
+  if (transproxy)
+    return transproxy;
+
+  Transport* transport = CreateTransport(content_name);
+  transport->SetIceRole(initiator_ ? ICEROLE_CONTROLLING : ICEROLE_CONTROLLED);
+  transport->SetIceTiebreaker(ice_tiebreaker_);
+  // TODO: Connect all the Transport signals to TransportProxy
+  // then to the BaseSession.
+  transport->SignalConnecting.connect(
+      this, &BaseSession::OnTransportConnecting);
+  transport->SignalWritableState.connect(
+      this, &BaseSession::OnTransportWritable);
+  transport->SignalRequestSignaling.connect(
+      this, &BaseSession::OnTransportRequestSignaling);
+  transport->SignalTransportError.connect(
+      this, &BaseSession::OnTransportSendError);
+  transport->SignalRouteChange.connect(
+      this, &BaseSession::OnTransportRouteChange);
+  transport->SignalCandidatesAllocationDone.connect(
+      this, &BaseSession::OnTransportCandidatesAllocationDone);
+  transport->SignalRoleConflict.connect(
+      this, &BaseSession::OnRoleConflict);
+  transport->SignalCompleted.connect(
+      this, &BaseSession::OnTransportCompleted);
+  transport->SignalFailed.connect(
+      this, &BaseSession::OnTransportFailed);
+
+  transproxy = new TransportProxy(worker_thread_, sid_, content_name,
+                                  new TransportWrapper(transport));
+  transproxy->SignalCandidatesReady.connect(
+      this, &BaseSession::OnTransportProxyCandidatesReady);
+  if (identity_)
+    transproxy->SetIdentity(identity_);
+  transports_[content_name] = transproxy;
+
+  return transproxy;
+}
+
+Transport* BaseSession::GetTransport(const std::string& content_name) {
+  TransportProxy* transproxy = GetTransportProxy(content_name);
+  if (transproxy == NULL)
+    return NULL;
+  return transproxy->impl();
+}
+
+TransportProxy* BaseSession::GetTransportProxy(
+    const std::string& content_name) {
+  TransportMap::iterator iter = transports_.find(content_name);
+  return (iter != transports_.end()) ? iter->second : NULL;
+}
+
+TransportProxy* BaseSession::GetTransportProxy(const Transport* transport) {
+  for (TransportMap::iterator iter = transports_.begin();
+       iter != transports_.end(); ++iter) {
+    TransportProxy* transproxy = iter->second;
+    if (transproxy->impl() == transport) {
+      return transproxy;
+    }
+  }
+  return NULL;
+}
+
+TransportProxy* BaseSession::GetFirstTransportProxy() {
+  if (transports_.empty())
+    return NULL;
+  return transports_.begin()->second;
+}
+
+void BaseSession::DestroyTransportProxy(
+    const std::string& content_name) {
+  TransportMap::iterator iter = transports_.find(content_name);
+  if (iter != transports_.end()) {
+    delete iter->second;
+    transports_.erase(content_name);
+  }
+}
+
+cricket::Transport* BaseSession::CreateTransport(
+    const std::string& content_name) {
+  ASSERT(transport_type_ == NS_GINGLE_P2P);
+  return new cricket::DtlsTransport<P2PTransport>(
+      signaling_thread(), worker_thread(), content_name,
+      port_allocator(), identity_);
+}
+
+bool BaseSession::GetStats(SessionStats* stats) {
+  for (TransportMap::iterator iter = transports_.begin();
+       iter != transports_.end(); ++iter) {
+    std::string proxy_id = iter->second->content_name();
+    // We are ignoring not-yet-instantiated transports.
+    if (iter->second->impl()) {
+      std::string transport_id = iter->second->impl()->content_name();
+      stats->proxy_to_transport[proxy_id] = transport_id;
+      if (stats->transport_stats.find(transport_id)
+          == stats->transport_stats.end()) {
+        TransportStats subinfos;
+        if (!iter->second->impl()->GetStats(&subinfos)) {
+          return false;
+        }
+        stats->transport_stats[transport_id] = subinfos;
+      }
+    }
+  }
+  return true;
+}
+
+void BaseSession::SetState(State state) {
+  ASSERT(signaling_thread_->IsCurrent());
+  if (state != state_) {
+    LogState(state_, state);
+    state_ = state;
+    SignalState(this, state_);
+    signaling_thread_->Post(this, MSG_STATE);
+  }
+  SignalNewDescription();
+}
+
+void BaseSession::SetError(Error error, const std::string& error_desc) {
+  ASSERT(signaling_thread_->IsCurrent());
+  if (error != error_) {
+    error_ = error;
+    error_desc_ = error_desc;
+    SignalError(this, error);
+  }
+}
+
+void BaseSession::OnSignalingReady() {
+  ASSERT(signaling_thread()->IsCurrent());
+  for (TransportMap::iterator iter = transports_.begin();
+       iter != transports_.end(); ++iter) {
+    iter->second->OnSignalingReady();
+  }
+}
+
+// TODO(juberti): Since PushdownLocalTD now triggers the connection process to
+// start, remove this method once everyone calls PushdownLocalTD.
+void BaseSession::SpeculativelyConnectAllTransportChannels() {
+  // Put all transports into the connecting state.
+  for (TransportMap::iterator iter = transports_.begin();
+       iter != transports_.end(); ++iter) {
+    iter->second->ConnectChannels();
+  }
+}
+
+bool BaseSession::OnRemoteCandidates(const std::string& content_name,
+                                     const Candidates& candidates,
+                                     std::string* error) {
+  // Give candidates to the appropriate transport, and tell that transport
+  // to start connecting, if it's not already doing so.
+  TransportProxy* transproxy = GetTransportProxy(content_name);
+  if (!transproxy) {
+    *error = "Unknown content name " + content_name;
+    return false;
+  }
+  if (!transproxy->OnRemoteCandidates(candidates, error)) {
+    return false;
+  }
+  // TODO(juberti): Remove this call once we can be sure that we always have
+  // a local transport description (which will trigger the connection).
+  transproxy->ConnectChannels();
+  return true;
+}
+
+bool BaseSession::MaybeEnableMuxingSupport() {
+  // We need both a local and remote description to decide if we should mux.
+  if ((state_ == STATE_SENTINITIATE ||
+      state_ == STATE_RECEIVEDINITIATE) &&
+      ((local_description_ == NULL) ||
+      (remote_description_ == NULL))) {
+    return false;
+  }
+
+  // In order to perform the multiplexing, we need all proxies to be in the
+  // negotiated state, i.e. to have implementations underneath.
+  // Ensure that this is the case, regardless of whether we are going to mux.
+  for (TransportMap::iterator iter = transports_.begin();
+       iter != transports_.end(); ++iter) {
+    ASSERT(iter->second->negotiated());
+    if (!iter->second->negotiated())
+      return false;
+  }
+
+  // If both sides agree to BUNDLE, mux all the specified contents onto the
+  // transport belonging to the first content name in the BUNDLE group.
+  // If the contents are already muxed, this will be a no-op.
+  // TODO(juberti): Should this check that local and remote have configured
+  // BUNDLE the same way?
+  bool candidates_allocated = IsCandidateAllocationDone();
+  const ContentGroup* local_bundle_group =
+      local_description()->GetGroupByName(GROUP_TYPE_BUNDLE);
+  const ContentGroup* remote_bundle_group =
+      remote_description()->GetGroupByName(GROUP_TYPE_BUNDLE);
+  if (local_bundle_group && remote_bundle_group &&
+      local_bundle_group->FirstContentName()) {
+    const std::string* content_name = local_bundle_group->FirstContentName();
+    const ContentInfo* content =
+        local_description_->GetContentByName(*content_name);
+    ASSERT(content != NULL);
+    if (!SetSelectedProxy(content->name, local_bundle_group)) {
+      LOG(LS_WARNING) << "Failed to set up BUNDLE";
+      return false;
+    }
+
+    // If we weren't done gathering before, we might be done now, as a result
+    // of enabling mux.
+    LOG(LS_INFO) << "Enabling BUNDLE, bundling onto transport: "
+                 << *content_name;
+    if (!candidates_allocated) {
+      MaybeCandidateAllocationDone();
+    }
+  } else {
+    LOG(LS_INFO) << "No BUNDLE information, not bundling.";
+  }
+  return true;
+}
+
+bool BaseSession::SetSelectedProxy(const std::string& content_name,
+                                   const ContentGroup* muxed_group) {
+  TransportProxy* selected_proxy = GetTransportProxy(content_name);
+  if (!selected_proxy) {
+    return false;
+  }
+
+  ASSERT(selected_proxy->negotiated());
+  for (TransportMap::iterator iter = transports_.begin();
+       iter != transports_.end(); ++iter) {
+    // If content is part of the mux group, then repoint its proxy at the
+    // transport object that we have chosen to mux onto. If the proxy
+    // is already pointing at the right object, it will be a no-op.
+    if (muxed_group->HasContentName(iter->first) &&
+        !iter->second->SetupMux(selected_proxy)) {
+      return false;
+    }
+  }
+  return true;
+}
+
+void BaseSession::OnTransportCandidatesAllocationDone(Transport* transport) {
+  // TODO(juberti): This is a clunky way of processing the done signal. Instead,
+  // TransportProxy should receive the done signal directly, set its allocated
+  // flag internally, and then reissue the done signal to Session.
+  // Overall we should make TransportProxy receive *all* the signals from
+  // Transport, since this removes the need to manually iterate over all
+  // the transports, as is needed to make sure signals are handled properly
+  // when BUNDLEing.
+  // TODO(juberti): Per b/7998978, devs and QA are hitting this assert in ways
+  // that make it prohibitively difficult to run dbg builds. Disabled for now.
+  //ASSERT(!IsCandidateAllocationDone());
+  for (TransportMap::iterator iter = transports_.begin();
+       iter != transports_.end(); ++iter) {
+    if (iter->second->impl() == transport) {
+      iter->second->set_candidates_allocated(true);
+    }
+  }
+  MaybeCandidateAllocationDone();
+}
+
+bool BaseSession::IsCandidateAllocationDone() const {
+  for (TransportMap::const_iterator iter = transports_.begin();
+       iter != transports_.end(); ++iter) {
+    if (!iter->second->candidates_allocated())
+      return false;
+  }
+  return true;
+}
+
+void BaseSession::MaybeCandidateAllocationDone() {
+  if (IsCandidateAllocationDone()) {
+    LOG(LS_INFO) << "Candidate gathering is complete.";
+    OnCandidatesAllocationDone();
+  }
+}
+
+void BaseSession::OnRoleConflict() {
+  if (role_switch_) {
+    LOG(LS_WARNING) << "Repeat of role conflict signal from Transport.";
+    return;
+  }
+
+  role_switch_ = true;
+  for (TransportMap::iterator iter = transports_.begin();
+       iter != transports_.end(); ++iter) {
+    // Role will be reverse of initial role setting.
+    IceRole role = initiator_ ? ICEROLE_CONTROLLED : ICEROLE_CONTROLLING;
+    iter->second->SetIceRole(role);
+  }
+}
+
+void BaseSession::LogState(State old_state, State new_state) {
+  LOG(LS_INFO) << "Session:" << id()
+               << " Old state:" << StateToString(old_state)
+               << " New state:" << StateToString(new_state)
+               << " Type:" << content_type()
+               << " Transport:" << transport_type();
+}
+
+// static
+bool BaseSession::GetTransportDescription(const SessionDescription* description,
+                                          const std::string& content_name,
+                                          TransportDescription* tdesc) {
+  if (!description || !tdesc) {
+    return false;
+  }
+  const TransportInfo* transport_info =
+      description->GetTransportInfoByName(content_name);
+  if (!transport_info) {
+    return false;
+  }
+  *tdesc = transport_info->description;
+  return true;
+}
+
+void BaseSession::SignalNewDescription() {
+  ContentAction action;
+  ContentSource source;
+  if (!GetContentAction(&action, &source)) {
+    return;
+  }
+  if (source == CS_LOCAL) {
+    SignalNewLocalDescription(this, action);
+  } else {
+    SignalNewRemoteDescription(this, action);
+  }
+}
+
+bool BaseSession::GetContentAction(ContentAction* action,
+                                   ContentSource* source) {
+  switch (state_) {
+    // new local description
+    case STATE_SENTINITIATE:
+      *action = CA_OFFER;
+      *source = CS_LOCAL;
+      break;
+    case STATE_SENTPRACCEPT:
+      *action = CA_PRANSWER;
+      *source = CS_LOCAL;
+      break;
+    case STATE_SENTACCEPT:
+      *action = CA_ANSWER;
+      *source = CS_LOCAL;
+      break;
+    // new remote description
+    case STATE_RECEIVEDINITIATE:
+      *action = CA_OFFER;
+      *source = CS_REMOTE;
+      break;
+    case STATE_RECEIVEDPRACCEPT:
+      *action = CA_PRANSWER;
+      *source = CS_REMOTE;
+      break;
+    case STATE_RECEIVEDACCEPT:
+      *action = CA_ANSWER;
+      *source = CS_REMOTE;
+      break;
+    default:
+      return false;
+  }
+  return true;
+}
+
+void BaseSession::OnMessage(rtc::Message *pmsg) {
+  switch (pmsg->message_id) {
+  case MSG_TIMEOUT:
+    // Session timeout has occured.
+    SetError(ERROR_TIME, "Session timeout has occured.");
+    break;
+
+  case MSG_STATE:
+    switch (state_) {
+    case STATE_SENTACCEPT:
+    case STATE_RECEIVEDACCEPT:
+      SetState(STATE_INPROGRESS);
+      break;
+
+    default:
+      // Explicitly ignoring some states here.
+      break;
+    }
+    break;
+  }
+}
+
+Session::Session(SessionManager* session_manager,
+                 const std::string& local_name,
+                 const std::string& initiator_name,
+                 const std::string& sid,
+                 const std::string& content_type,
+                 SessionClient* client)
+    : BaseSession(session_manager->signaling_thread(),
+                  session_manager->worker_thread(),
+                  session_manager->port_allocator(),
+                  sid, content_type, initiator_name == local_name) {
+  ASSERT(client != NULL);
+  session_manager_ = session_manager;
+  local_name_ = local_name;
+  initiator_name_ = initiator_name;
+  transport_parser_ = new P2PTransportParser();
+  client_ = client;
+  initiate_acked_ = false;
+  current_protocol_ = PROTOCOL_HYBRID;
+}
+
+Session::~Session() {
+  delete transport_parser_;
+}
+
+bool Session::Initiate(const std::string& to,
+                       const SessionDescription* sdesc) {
+  ASSERT(signaling_thread()->IsCurrent());
+  SessionError error;
+
+  // Only from STATE_INIT
+  if (state() != STATE_INIT)
+    return false;
+
+  // Setup for signaling.
+  set_remote_name(to);
+  set_local_description(sdesc);
+  if (!CreateTransportProxies(GetEmptyTransportInfos(sdesc->contents()),
+                              &error)) {
+    LOG(LS_ERROR) << "Could not create transports: " << error.text;
+    return false;
+  }
+
+  if (!SendInitiateMessage(sdesc, &error)) {
+    LOG(LS_ERROR) << "Could not send initiate message: " << error.text;
+    return false;
+  }
+
+  // We need to connect transport proxy and impl here so that we can process
+  // the TransportDescriptions.
+  SpeculativelyConnectAllTransportChannels();
+
+  PushdownTransportDescription(CS_LOCAL, CA_OFFER, NULL);
+  SetState(Session::STATE_SENTINITIATE);
+  return true;
+}
+
+bool Session::Accept(const SessionDescription* sdesc) {
+  ASSERT(signaling_thread()->IsCurrent());
+
+  // Only if just received initiate
+  if (state() != STATE_RECEIVEDINITIATE)
+    return false;
+
+  // Setup for signaling.
+  set_local_description(sdesc);
+
+  SessionError error;
+  if (!SendAcceptMessage(sdesc, &error)) {
+    LOG(LS_ERROR) << "Could not send accept message: " << error.text;
+    return false;
+  }
+  // TODO(juberti): Add BUNDLE support to transport-info messages.
+  PushdownTransportDescription(CS_LOCAL, CA_ANSWER, NULL);
+  MaybeEnableMuxingSupport();  // Enable transport channel mux if supported.
+  SetState(Session::STATE_SENTACCEPT);
+  return true;
+}
+
+bool Session::Reject(const std::string& reason) {
+  ASSERT(signaling_thread()->IsCurrent());
+
+  // Reject is sent in response to an initiate or modify, to reject the
+  // request
+  if (state() != STATE_RECEIVEDINITIATE && state() != STATE_RECEIVEDMODIFY)
+    return false;
+
+  SessionError error;
+  if (!SendRejectMessage(reason, &error)) {
+    LOG(LS_ERROR) << "Could not send reject message: " << error.text;
+    return false;
+  }
+
+  SetState(STATE_SENTREJECT);
+  return true;
+}
+
+bool Session::TerminateWithReason(const std::string& reason) {
+  ASSERT(signaling_thread()->IsCurrent());
+
+  // Either side can terminate, at any time.
+  switch (state()) {
+    case STATE_SENTTERMINATE:
+    case STATE_RECEIVEDTERMINATE:
+      return false;
+
+    case STATE_SENTREJECT:
+    case STATE_RECEIVEDREJECT:
+      // We don't need to send terminate if we sent or received a reject...
+      // it's implicit.
+      break;
+
+    default:
+      SessionError error;
+      if (!SendTerminateMessage(reason, &error)) {
+        LOG(LS_ERROR) << "Could not send terminate message: " << error.text;
+        return false;
+      }
+      break;
+  }
+
+  SetState(STATE_SENTTERMINATE);
+  return true;
+}
+
+bool Session::SendInfoMessage(const XmlElements& elems,
+                              const std::string& remote_name) {
+  ASSERT(signaling_thread()->IsCurrent());
+  SessionError error;
+  if (!SendMessage(ACTION_SESSION_INFO, elems, remote_name, &error)) {
+    LOG(LS_ERROR) << "Could not send info message " << error.text;
+    return false;
+  }
+  return true;
+}
+
+bool Session::SendDescriptionInfoMessage(const ContentInfos& contents) {
+  XmlElements elems;
+  WriteError write_error;
+  if (!WriteDescriptionInfo(current_protocol_,
+                            contents,
+                            GetContentParsers(),
+                            &elems, &write_error)) {
+    LOG(LS_ERROR) << "Could not write description info message: "
+                  << write_error.text;
+    return false;
+  }
+  SessionError error;
+  if (!SendMessage(ACTION_DESCRIPTION_INFO, elems, &error)) {
+    LOG(LS_ERROR) << "Could not send description info message: "
+                  << error.text;
+    return false;
+  }
+  return true;
+}
+
+TransportInfos Session::GetEmptyTransportInfos(
+    const ContentInfos& contents) const {
+  TransportInfos tinfos;
+  for (ContentInfos::const_iterator content = contents.begin();
+       content != contents.end(); ++content) {
+    tinfos.push_back(TransportInfo(content->name,
+                                   TransportDescription(transport_type(),
+                                                        std::string(),
+                                                        std::string())));
+  }
+  return tinfos;
+}
+
+bool Session::OnRemoteCandidates(
+    const TransportInfos& tinfos, ParseError* error) {
+  for (TransportInfos::const_iterator tinfo = tinfos.begin();
+       tinfo != tinfos.end(); ++tinfo) {
+    std::string str_error;
+    if (!BaseSession::OnRemoteCandidates(
+        tinfo->content_name, tinfo->description.candidates, &str_error)) {
+      return BadParse(str_error, error);
+    }
+  }
+  return true;
+}
+
+bool Session::CreateTransportProxies(const TransportInfos& tinfos,
+                                     SessionError* error) {
+  for (TransportInfos::const_iterator tinfo = tinfos.begin();
+       tinfo != tinfos.end(); ++tinfo) {
+    if (tinfo->description.transport_type != transport_type()) {
+      error->SetText("No supported transport in offer.");
+      return false;
+    }
+
+    GetOrCreateTransportProxy(tinfo->content_name);
+  }
+  return true;
+}
+
+TransportParserMap Session::GetTransportParsers() {
+  TransportParserMap parsers;
+  parsers[transport_type()] = transport_parser_;
+  return parsers;
+}
+
+CandidateTranslatorMap Session::GetCandidateTranslators() {
+  CandidateTranslatorMap translators;
+  // NOTE: This technique makes it impossible to parse G-ICE
+  // candidates in session-initiate messages because the channels
+  // aren't yet created at that point.  Since we don't use candidates
+  // in session-initiate messages, we should be OK.  Once we switch to
+  // ICE, this translation shouldn't be necessary.
+  for (TransportMap::const_iterator iter = transport_proxies().begin();
+       iter != transport_proxies().end(); ++iter) {
+    translators[iter->first] = iter->second;
+  }
+  return translators;
+}
+
+ContentParserMap Session::GetContentParsers() {
+  ContentParserMap parsers;
+  parsers[content_type()] = client_;
+  // We need to be able parse both RTP-based and SCTP-based Jingle
+  // with the same client.
+  if (content_type() == NS_JINGLE_RTP) {
+    parsers[NS_JINGLE_DRAFT_SCTP] = client_;
+  }
+  return parsers;
+}
+
+void Session::OnTransportRequestSignaling(Transport* transport) {
+  ASSERT(signaling_thread()->IsCurrent());
+  TransportProxy* transproxy = GetTransportProxy(transport);
+  ASSERT(transproxy != NULL);
+  if (transproxy) {
+    // Reset candidate allocation status for the transport proxy.
+    transproxy->set_candidates_allocated(false);
+  }
+  SignalRequestSignaling(this);
+}
+
+void Session::OnTransportConnecting(Transport* transport) {
+  // This is an indication that we should begin watching the writability
+  // state of the transport.
+  OnTransportWritable(transport);
+}
+
+void Session::OnTransportWritable(Transport* transport) {
+  ASSERT(signaling_thread()->IsCurrent());
+
+  // If the transport is not writable, start a timer to make sure that it
+  // becomes writable within a reasonable amount of time.  If it does not, we
+  // terminate since we can't actually send data.  If the transport is writable,
+  // cancel the timer.  Note that writability transitions may occur repeatedly
+  // during the lifetime of the session.
+  signaling_thread()->Clear(this, MSG_TIMEOUT);
+  if (transport->HasChannels() && !transport->writable()) {
+    signaling_thread()->PostDelayed(
+        session_manager_->session_timeout() * 1000, this, MSG_TIMEOUT);
+  }
+}
+
+void Session::OnTransportProxyCandidatesReady(TransportProxy* transproxy,
+                                              const Candidates& candidates) {
+  ASSERT(signaling_thread()->IsCurrent());
+  if (transproxy != NULL) {
+    if (initiator() && !initiate_acked_) {
+      // TODO: This is to work around server re-ordering
+      // messages.  We send the candidates once the session-initiate
+      // is acked.  Once we have fixed the server to guarantee message
+      // order, we can remove this case.
+      transproxy->AddUnsentCandidates(candidates);
+    } else {
+      if (!transproxy->negotiated()) {
+        transproxy->AddSentCandidates(candidates);
+      }
+      SessionError error;
+      if (!SendTransportInfoMessage(transproxy, candidates, &error)) {
+        LOG(LS_ERROR) << "Could not send transport info message: "
+                      << error.text;
+        return;
+      }
+    }
+  }
+}
+
+void Session::OnTransportSendError(Transport* transport,
+                                   const buzz::XmlElement* stanza,
+                                   const buzz::QName& name,
+                                   const std::string& type,
+                                   const std::string& text,
+                                   const buzz::XmlElement* extra_info) {
+  ASSERT(signaling_thread()->IsCurrent());
+  SignalErrorMessage(this, stanza, name, type, text, extra_info);
+}
+
+void Session::OnIncomingMessage(const SessionMessage& msg) {
+  ASSERT(signaling_thread()->IsCurrent());
+  ASSERT(state() == STATE_INIT || msg.from == remote_name());
+
+  if (current_protocol_== PROTOCOL_HYBRID) {
+    if (msg.protocol == PROTOCOL_GINGLE) {
+      current_protocol_ = PROTOCOL_GINGLE;
+    } else {
+      current_protocol_ = PROTOCOL_JINGLE;
+    }
+  }
+
+  bool valid = false;
+  MessageError error;
+  switch (msg.type) {
+    case ACTION_SESSION_INITIATE:
+      valid = OnInitiateMessage(msg, &error);
+      break;
+    case ACTION_SESSION_INFO:
+      valid = OnInfoMessage(msg);
+      break;
+    case ACTION_SESSION_ACCEPT:
+      valid = OnAcceptMessage(msg, &error);
+      break;
+    case ACTION_SESSION_REJECT:
+      valid = OnRejectMessage(msg, &error);
+      break;
+    case ACTION_SESSION_TERMINATE:
+      valid = OnTerminateMessage(msg, &error);
+      break;
+    case ACTION_TRANSPORT_INFO:
+      valid = OnTransportInfoMessage(msg, &error);
+      break;
+    case ACTION_TRANSPORT_ACCEPT:
+      valid = OnTransportAcceptMessage(msg, &error);
+      break;
+    case ACTION_DESCRIPTION_INFO:
+      valid = OnDescriptionInfoMessage(msg, &error);
+      break;
+    default:
+      valid = BadMessage(buzz::QN_STANZA_BAD_REQUEST,
+                         "unknown session message type",
+                         &error);
+  }
+
+  if (valid) {
+    SendAcknowledgementMessage(msg.stanza);
+  } else {
+    SignalErrorMessage(this, msg.stanza, error.type,
+                       "modify", error.text, NULL);
+  }
+}
+
+void Session::OnIncomingResponse(const buzz::XmlElement* orig_stanza,
+                                 const buzz::XmlElement* response_stanza,
+                                 const SessionMessage& msg) {
+  ASSERT(signaling_thread()->IsCurrent());
+
+  if (msg.type == ACTION_SESSION_INITIATE) {
+    OnInitiateAcked();
+  }
+}
+
+void Session::OnInitiateAcked() {
+  // TODO: This is to work around server re-ordering
+  // messages.  We send the candidates once the session-initiate
+  // is acked.  Once we have fixed the server to guarantee message
+  // order, we can remove this case.
+  if (!initiate_acked_) {
+    initiate_acked_ = true;
+    SessionError error;
+    SendAllUnsentTransportInfoMessages(&error);
+  }
+}
+
+void Session::OnFailedSend(const buzz::XmlElement* orig_stanza,
+                           const buzz::XmlElement* error_stanza) {
+  ASSERT(signaling_thread()->IsCurrent());
+
+  SessionMessage msg;
+  ParseError parse_error;
+  if (!ParseSessionMessage(orig_stanza, &msg, &parse_error)) {
+    LOG(LS_ERROR) << "Error parsing failed send: " << parse_error.text
+                  << ":" << orig_stanza;
+    return;
+  }
+
+  // If the error is a session redirect, call OnRedirectError, which will
+  // continue the session with a new remote JID.
+  SessionRedirect redirect;
+  if (FindSessionRedirect(error_stanza, &redirect)) {
+    SessionError error;
+    if (!OnRedirectError(redirect, &error)) {
+      // TODO: Should we send a message back?  The standard
+      // says nothing about it.
+      std::ostringstream desc;
+      desc << "Failed to redirect: " << error.text;
+      LOG(LS_ERROR) << desc.str();
+      SetError(ERROR_RESPONSE, desc.str());
+    }
+    return;
+  }
+
+  std::string error_type = "cancel";
+
+  const buzz::XmlElement* error = error_stanza->FirstNamed(buzz::QN_ERROR);
+  if (error) {
+    error_type = error->Attr(buzz::QN_TYPE);
+
+    LOG(LS_ERROR) << "Session error:\n" << error->Str() << "\n"
+                  << "in response to:\n" << orig_stanza->Str();
+  } else {
+    // don't crash if <error> is missing
+    LOG(LS_ERROR) << "Session error without <error/> element, ignoring";
+    return;
+  }
+
+  if (msg.type == ACTION_TRANSPORT_INFO) {
+    // Transport messages frequently generate errors because they are sent right
+    // when we detect a network failure.  For that reason, we ignore such
+    // errors, because if we do not establish writability again, we will
+    // terminate anyway.  The exceptions are transport-specific error tags,
+    // which we pass on to the respective transport.
+  } else if ((error_type != "continue") && (error_type != "wait")) {
+    // We do not set an error if the other side said it is okay to continue
+    // (possibly after waiting).  These errors can be ignored.
+    SetError(ERROR_RESPONSE, "");
+  }
+}
+
+bool Session::OnInitiateMessage(const SessionMessage& msg,
+                                MessageError* error) {
+  if (!CheckState(STATE_INIT, error))
+    return false;
+
+  SessionInitiate init;
+  if (!ParseSessionInitiate(msg.protocol, msg.action_elem,
+                            GetContentParsers(), GetTransportParsers(),
+                            GetCandidateTranslators(),
+                            &init, error))
+    return false;
+
+  SessionError session_error;
+  if (!CreateTransportProxies(init.transports, &session_error)) {
+    return BadMessage(buzz::QN_STANZA_NOT_ACCEPTABLE,
+                      session_error.text, error);
+  }
+
+  set_remote_name(msg.from);
+  set_initiator_name(msg.initiator);
+  set_remote_description(new SessionDescription(init.ClearContents(),
+                                                init.transports,
+                                                init.groups));
+  // Updating transport with TransportDescription.
+  PushdownTransportDescription(CS_REMOTE, CA_OFFER, NULL);
+  SetState(STATE_RECEIVEDINITIATE);
+
+  // Users of Session may listen to state change and call Reject().
+  if (state() != STATE_SENTREJECT) {
+    if (!OnRemoteCandidates(init.transports, error))
+      return false;
+
+    // TODO(juberti): Auto-generate and push down the local transport answer.
+    // This is necessary for trickling to work with RFC 5245 ICE.
+  }
+  return true;
+}
+
+bool Session::OnAcceptMessage(const SessionMessage& msg, MessageError* error) {
+  if (!CheckState(STATE_SENTINITIATE, error))
+    return false;
+
+  SessionAccept accept;
+  if (!ParseSessionAccept(msg.protocol, msg.action_elem,
+                          GetContentParsers(), GetTransportParsers(),
+                          GetCandidateTranslators(),
+                          &accept, error)) {
+    return false;
+  }
+
+  // If we get an accept, we can assume the initiate has been
+  // received, even if we haven't gotten an IQ response.
+  OnInitiateAcked();
+
+  set_remote_description(new SessionDescription(accept.ClearContents(),
+                                                accept.transports,
+                                                accept.groups));
+  // Updating transport with TransportDescription.
+  PushdownTransportDescription(CS_REMOTE, CA_ANSWER, NULL);
+  MaybeEnableMuxingSupport();  // Enable transport channel mux if supported.
+  SetState(STATE_RECEIVEDACCEPT);
+
+  if (!OnRemoteCandidates(accept.transports, error))
+    return false;
+
+  return true;
+}
+
+bool Session::OnRejectMessage(const SessionMessage& msg, MessageError* error) {
+  if (!CheckState(STATE_SENTINITIATE, error))
+    return false;
+
+  SetState(STATE_RECEIVEDREJECT);
+  return true;
+}
+
+bool Session::OnInfoMessage(const SessionMessage& msg) {
+  SignalInfoMessage(this, msg.action_elem);
+  return true;
+}
+
+bool Session::OnTerminateMessage(const SessionMessage& msg,
+                                 MessageError* error) {
+  SessionTerminate term;
+  if (!ParseSessionTerminate(msg.protocol, msg.action_elem, &term, error))
+    return false;
+
+  SignalReceivedTerminateReason(this, term.reason);
+  if (term.debug_reason != buzz::STR_EMPTY) {
+    LOG(LS_VERBOSE) << "Received error on call: " << term.debug_reason;
+  }
+
+  SetState(STATE_RECEIVEDTERMINATE);
+  return true;
+}
+
+bool Session::OnTransportInfoMessage(const SessionMessage& msg,
+                                     MessageError* error) {
+  TransportInfos tinfos;
+  if (!ParseTransportInfos(msg.protocol, msg.action_elem,
+                           initiator_description()->contents(),
+                           GetTransportParsers(), GetCandidateTranslators(),
+                           &tinfos, error))
+    return false;
+
+  if (!OnRemoteCandidates(tinfos, error))
+    return false;
+
+  return true;
+}
+
+bool Session::OnTransportAcceptMessage(const SessionMessage& msg,
+                                       MessageError* error) {
+  // TODO: Currently here only for compatibility with
+  // Gingle 1.1 clients (notably, Google Voice).
+  return true;
+}
+
+bool Session::OnDescriptionInfoMessage(const SessionMessage& msg,
+                              MessageError* error) {
+  if (!CheckState(STATE_INPROGRESS, error))
+    return false;
+
+  DescriptionInfo description_info;
+  if (!ParseDescriptionInfo(msg.protocol, msg.action_elem,
+                            GetContentParsers(), GetTransportParsers(),
+                            GetCandidateTranslators(),
+                            &description_info, error)) {
+    return false;
+  }
+
+  ContentInfos& updated_contents = description_info.contents;
+
+  // TODO: Currently, reflector sends back
+  // video stream updates even for an audio-only call, which causes
+  // this to fail.  Put this back once reflector is fixed.
+  //
+  // ContentInfos::iterator it;
+  // First, ensure all updates are valid before modifying remote_description_.
+  // for (it = updated_contents.begin(); it != updated_contents.end(); ++it) {
+  //   if (remote_description()->GetContentByName(it->name) == NULL) {
+  //     return false;
+  //   }
+  // }
+
+  // TODO: We used to replace contents from an update, but
+  // that no longer works with partial updates.  We need to figure out
+  // a way to merge patial updates into contents.  For now, users of
+  // Session should listen to SignalRemoteDescriptionUpdate and handle
+  // updates.  They should not expect remote_description to be the
+  // latest value.
+  //
+  // for (it = updated_contents.begin(); it != updated_contents.end(); ++it) {
+  //     remote_description()->RemoveContentByName(it->name);
+  //     remote_description()->AddContent(it->name, it->type, it->description);
+  //   }
+  // }
+
+  SignalRemoteDescriptionUpdate(this, updated_contents);
+  return true;
+}
+
+bool BareJidsEqual(const std::string& name1,
+                   const std::string& name2) {
+  buzz::Jid jid1(name1);
+  buzz::Jid jid2(name2);
+
+  return jid1.IsValid() && jid2.IsValid() && jid1.BareEquals(jid2);
+}
+
+bool Session::OnRedirectError(const SessionRedirect& redirect,
+                              SessionError* error) {
+  MessageError message_error;
+  if (!CheckState(STATE_SENTINITIATE, &message_error)) {
+    return BadWrite(message_error.text, error);
+  }
+
+  if (!BareJidsEqual(remote_name(), redirect.target))
+    return BadWrite("Redirection not allowed: must be the same bare jid.",
+                    error);
+
+  // When we receive a redirect, we point the session at the new JID
+  // and resend the candidates.
+  set_remote_name(redirect.target);
+  return (SendInitiateMessage(local_description(), error) &&
+          ResendAllTransportInfoMessages(error));
+}
+
+bool Session::CheckState(State expected, MessageError* error) {
+  if (state() != expected) {
+    // The server can deliver messages out of order/repeated for various
+    // reasons. For example, if the server does not recive our iq response,
+    // it could assume that the iq it sent was lost, and will then send
+    // it again. Ideally, we should implement reliable messaging with
+    // duplicate elimination.
+    return BadMessage(buzz::QN_STANZA_NOT_ALLOWED,
+                      "message not allowed in current state",
+                      error);
+  }
+  return true;
+}
+
+void Session::SetError(Error error, const std::string& error_desc) {
+  BaseSession::SetError(error, error_desc);
+  if (error != ERROR_NONE)
+    signaling_thread()->Post(this, MSG_ERROR);
+}
+
+void Session::OnMessage(rtc::Message* pmsg) {
+  // preserve this because BaseSession::OnMessage may modify it
+  State orig_state = state();
+
+  BaseSession::OnMessage(pmsg);
+
+  switch (pmsg->message_id) {
+  case MSG_ERROR:
+    TerminateWithReason(STR_TERMINATE_ERROR);
+    break;
+
+  case MSG_STATE:
+    switch (orig_state) {
+    case STATE_SENTREJECT:
+    case STATE_RECEIVEDREJECT:
+      // Assume clean termination.
+      Terminate();
+      break;
+
+    case STATE_SENTTERMINATE:
+    case STATE_RECEIVEDTERMINATE:
+      session_manager_->DestroySession(this);
+      break;
+
+    default:
+      // Explicitly ignoring some states here.
+      break;
+    }
+    break;
+  }
+}
+
+bool Session::SendInitiateMessage(const SessionDescription* sdesc,
+                                  SessionError* error) {
+  SessionInitiate init;
+  init.contents = sdesc->contents();
+  init.transports = GetEmptyTransportInfos(init.contents);
+  init.groups = sdesc->groups();
+  return SendMessage(ACTION_SESSION_INITIATE, init, error);
+}
+
+bool Session::WriteSessionAction(
+    SignalingProtocol protocol, const SessionInitiate& init,
+    XmlElements* elems, WriteError* error) {
+  return WriteSessionInitiate(protocol, init.contents, init.transports,
+                              GetContentParsers(), GetTransportParsers(),
+                              GetCandidateTranslators(), init.groups,
+                              elems, error);
+}
+
+bool Session::SendAcceptMessage(const SessionDescription* sdesc,
+                                SessionError* error) {
+  XmlElements elems;
+  if (!WriteSessionAccept(current_protocol_,
+                          sdesc->contents(),
+                          GetEmptyTransportInfos(sdesc->contents()),
+                          GetContentParsers(), GetTransportParsers(),
+                          GetCandidateTranslators(), sdesc->groups(),
+                          &elems, error)) {
+    return false;
+  }
+  return SendMessage(ACTION_SESSION_ACCEPT, elems, error);
+}
+
+bool Session::SendRejectMessage(const std::string& reason,
+                                SessionError* error) {
+  SessionTerminate term(reason);
+  return SendMessage(ACTION_SESSION_REJECT, term, error);
+}
+
+bool Session::SendTerminateMessage(const std::string& reason,
+                                   SessionError* error) {
+  SessionTerminate term(reason);
+  return SendMessage(ACTION_SESSION_TERMINATE, term, error);
+}
+
+bool Session::WriteSessionAction(SignalingProtocol protocol,
+                                 const SessionTerminate& term,
+                                 XmlElements* elems, WriteError* error) {
+  WriteSessionTerminate(protocol, term, elems);
+  return true;
+}
+
+bool Session::SendTransportInfoMessage(const TransportInfo& tinfo,
+                                       SessionError* error) {
+  return SendMessage(ACTION_TRANSPORT_INFO, tinfo, error);
+}
+
+bool Session::SendTransportInfoMessage(const TransportProxy* transproxy,
+                                       const Candidates& candidates,
+                                       SessionError* error) {
+  return SendTransportInfoMessage(TransportInfo(transproxy->content_name(),
+      TransportDescription(transproxy->type(), std::vector<std::string>(),
+                           std::string(), std::string(), ICEMODE_FULL,
+                           CONNECTIONROLE_NONE, NULL, candidates)), error);
+}
+
+bool Session::WriteSessionAction(SignalingProtocol protocol,
+                                 const TransportInfo& tinfo,
+                                 XmlElements* elems, WriteError* error) {
+  TransportInfos tinfos;
+  tinfos.push_back(tinfo);
+  return WriteTransportInfos(protocol, tinfos,
+                             GetTransportParsers(), GetCandidateTranslators(),
+                             elems, error);
+}
+
+bool Session::ResendAllTransportInfoMessages(SessionError* error) {
+  for (TransportMap::const_iterator iter = transport_proxies().begin();
+       iter != transport_proxies().end(); ++iter) {
+    TransportProxy* transproxy = iter->second;
+    if (transproxy->sent_candidates().size() > 0) {
+      if (!SendTransportInfoMessage(
+              transproxy, transproxy->sent_candidates(), error)) {
+        LOG(LS_ERROR) << "Could not resend transport info messages: "
+                      << error->text;
+        return false;
+      }
+      transproxy->ClearSentCandidates();
+    }
+  }
+  return true;
+}
+
+bool Session::SendAllUnsentTransportInfoMessages(SessionError* error) {
+  for (TransportMap::const_iterator iter = transport_proxies().begin();
+       iter != transport_proxies().end(); ++iter) {
+    TransportProxy* transproxy = iter->second;
+    if (transproxy->unsent_candidates().size() > 0) {
+      if (!SendTransportInfoMessage(
+              transproxy, transproxy->unsent_candidates(), error)) {
+        LOG(LS_ERROR) << "Could not send unsent transport info messages: "
+                      << error->text;
+        return false;
+      }
+      transproxy->ClearUnsentCandidates();
+    }
+  }
+  return true;
+}
+
+bool Session::SendMessage(ActionType type, const XmlElements& action_elems,
+                          SessionError* error) {
+    return SendMessage(type, action_elems, remote_name(), error);
+}
+
+bool Session::SendMessage(ActionType type, const XmlElements& action_elems,
+                          const std::string& remote_name, SessionError* error) {
+  rtc::scoped_ptr<buzz::XmlElement> stanza(
+      new buzz::XmlElement(buzz::QN_IQ));
+
+  SessionMessage msg(current_protocol_, type, id(), initiator_name());
+  msg.to = remote_name;
+  WriteSessionMessage(msg, action_elems, stanza.get());
+
+  SignalOutgoingMessage(this, stanza.get());
+  return true;
+}
+
+template <typename Action>
+bool Session::SendMessage(ActionType type, const Action& action,
+                          SessionError* error) {
+  rtc::scoped_ptr<buzz::XmlElement> stanza(
+      new buzz::XmlElement(buzz::QN_IQ));
+  if (!WriteActionMessage(type, action, stanza.get(), error))
+    return false;
+
+  SignalOutgoingMessage(this, stanza.get());
+  return true;
+}
+
+template <typename Action>
+bool Session::WriteActionMessage(ActionType type, const Action& action,
+                                 buzz::XmlElement* stanza,
+                                 WriteError* error) {
+  if (current_protocol_ == PROTOCOL_HYBRID) {
+    if (!WriteActionMessage(PROTOCOL_JINGLE, type, action, stanza, error))
+      return false;
+    if (!WriteActionMessage(PROTOCOL_GINGLE, type, action, stanza, error))
+      return false;
+  } else {
+    if (!WriteActionMessage(current_protocol_, type, action, stanza, error))
+      return false;
+  }
+  return true;
+}
+
+template <typename Action>
+bool Session::WriteActionMessage(SignalingProtocol protocol,
+                                 ActionType type, const Action& action,
+                                 buzz::XmlElement* stanza, WriteError* error) {
+  XmlElements action_elems;
+  if (!WriteSessionAction(protocol, action, &action_elems, error))
+    return false;
+
+  SessionMessage msg(protocol, type, id(), initiator_name());
+  msg.to = remote_name();
+
+  WriteSessionMessage(msg, action_elems, stanza);
+  return true;
+}
+
+void Session::SendAcknowledgementMessage(const buzz::XmlElement* stanza) {
+  rtc::scoped_ptr<buzz::XmlElement> ack(
+      new buzz::XmlElement(buzz::QN_IQ));
+  ack->SetAttr(buzz::QN_TO, remote_name());
+  ack->SetAttr(buzz::QN_ID, stanza->Attr(buzz::QN_ID));
+  ack->SetAttr(buzz::QN_TYPE, "result");
+
+  SignalOutgoingMessage(this, ack.get());
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/session.h b/webrtc/p2p/base/session.h
new file mode 100644
index 0000000..f5eaf41
--- /dev/null
+++ b/webrtc/p2p/base/session.h
@@ -0,0 +1,730 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_SESSION_H_
+#define WEBRTC_P2P_BASE_SESSION_H_
+
+#include <list>
+#include <map>
+#include <string>
+#include <vector>
+
+#include "webrtc/p2p/base/parsing.h"
+#include "webrtc/p2p/base/port.h"
+#include "webrtc/p2p/base/sessionclient.h"
+#include "webrtc/p2p/base/sessionmanager.h"
+#include "webrtc/p2p/base/sessionmessages.h"
+#include "webrtc/p2p/base/transport.h"
+#include "webrtc/libjingle/xmllite/xmlelement.h"
+#include "webrtc/libjingle/xmpp/constants.h"
+#include "webrtc/base/refcount.h"
+#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/scoped_ref_ptr.h"
+#include "webrtc/base/socketaddress.h"
+
+namespace cricket {
+
+class BaseSession;
+class P2PTransportChannel;
+class Transport;
+class TransportChannel;
+class TransportChannelProxy;
+class TransportChannelImpl;
+
+typedef rtc::RefCountedObject<rtc::scoped_ptr<Transport> >
+TransportWrapper;
+
+// Used for errors that will send back a specific error message to the
+// remote peer.  We add "type" to the errors because it's needed for
+// SignalErrorMessage.
+struct MessageError : ParseError {
+  buzz::QName type;
+
+  // if unset, assume type is a parse error
+  MessageError() : ParseError(), type(buzz::QN_STANZA_BAD_REQUEST) {}
+
+  void SetType(const buzz::QName type) {
+    this->type = type;
+  }
+};
+
+// Used for errors that may be returned by public session methods that
+// can fail.
+// TODO: Use this error in Session::Initiate and
+// Session::Accept.
+struct SessionError : WriteError {
+};
+
+// Bundles a Transport and ChannelMap together. ChannelMap is used to
+// create transport channels before receiving or sending a session
+// initiate, and for speculatively connecting channels.  Previously, a
+// session had one ChannelMap and transport.  Now, with multiple
+// transports per session, we need multiple ChannelMaps as well.
+
+typedef std::map<int, TransportChannelProxy*> ChannelMap;
+
+class TransportProxy : public sigslot::has_slots<>,
+                       public CandidateTranslator {
+ public:
+  TransportProxy(
+      rtc::Thread* worker_thread,
+      const std::string& sid,
+      const std::string& content_name,
+      TransportWrapper* transport)
+      : worker_thread_(worker_thread),
+        sid_(sid),
+        content_name_(content_name),
+        transport_(transport),
+        connecting_(false),
+        negotiated_(false),
+        sent_candidates_(false),
+        candidates_allocated_(false),
+        local_description_set_(false),
+        remote_description_set_(false) {
+    transport_->get()->SignalCandidatesReady.connect(
+        this, &TransportProxy::OnTransportCandidatesReady);
+  }
+  ~TransportProxy();
+
+  const std::string& content_name() const { return content_name_; }
+  // TODO(juberti): It's not good form to expose the object you're wrapping,
+  // since callers can mutate it. Can we make this return a const Transport*?
+  Transport* impl() const { return transport_->get(); }
+
+  const std::string& type() const;
+  bool negotiated() const { return negotiated_; }
+  const Candidates& sent_candidates() const { return sent_candidates_; }
+  const Candidates& unsent_candidates() const { return unsent_candidates_; }
+  bool candidates_allocated() const { return candidates_allocated_; }
+  void set_candidates_allocated(bool allocated) {
+    candidates_allocated_ = allocated;
+  }
+
+  TransportChannel* GetChannel(int component);
+  TransportChannel* CreateChannel(const std::string& channel_name,
+                                  int component);
+  bool HasChannel(int component);
+  void DestroyChannel(int component);
+
+  void AddSentCandidates(const Candidates& candidates);
+  void AddUnsentCandidates(const Candidates& candidates);
+  void ClearSentCandidates() { sent_candidates_.clear(); }
+  void ClearUnsentCandidates() { unsent_candidates_.clear(); }
+
+  // Start the connection process for any channels, creating impls if needed.
+  void ConnectChannels();
+  // Hook up impls to the proxy channels. Doesn't change connect state.
+  void CompleteNegotiation();
+
+  // Mux this proxy onto the specified proxy's transport.
+  bool SetupMux(TransportProxy* proxy);
+
+  // Simple functions that thunk down to the same functions on Transport.
+  void SetIceRole(IceRole role);
+  void SetIdentity(rtc::SSLIdentity* identity);
+  bool SetLocalTransportDescription(const TransportDescription& description,
+                                    ContentAction action,
+                                    std::string* error_desc);
+  bool SetRemoteTransportDescription(const TransportDescription& description,
+                                     ContentAction action,
+                                     std::string* error_desc);
+  void OnSignalingReady();
+  bool OnRemoteCandidates(const Candidates& candidates, std::string* error);
+
+  // CandidateTranslator methods.
+  virtual bool GetChannelNameFromComponent(
+      int component, std::string* channel_name) const;
+  virtual bool GetComponentFromChannelName(
+      const std::string& channel_name, int* component) const;
+
+  // Called when a transport signals that it has new candidates.
+  void OnTransportCandidatesReady(cricket::Transport* transport,
+                                  const Candidates& candidates) {
+    SignalCandidatesReady(this, candidates);
+  }
+
+  bool local_description_set() const {
+    return local_description_set_;
+  }
+  bool remote_description_set() const {
+    return remote_description_set_;
+  }
+
+  // Handles sending of ready candidates and receiving of remote candidates.
+  sigslot::signal2<TransportProxy*,
+                         const std::vector<Candidate>&> SignalCandidatesReady;
+
+ private:
+  TransportChannelProxy* GetChannelProxy(int component) const;
+  TransportChannelProxy* GetChannelProxyByName(const std::string& name) const;
+
+  TransportChannelImpl* GetOrCreateChannelProxyImpl(int component);
+  TransportChannelImpl* GetOrCreateChannelProxyImpl_w(int component);
+
+  // Manipulators of transportchannelimpl in channel proxy.
+  void SetupChannelProxy(int component,
+                           TransportChannelProxy* proxy);
+  void SetupChannelProxy_w(int component,
+                             TransportChannelProxy* proxy);
+  void ReplaceChannelProxyImpl(TransportChannelProxy* proxy,
+                               TransportChannelImpl* impl);
+  void ReplaceChannelProxyImpl_w(TransportChannelProxy* proxy,
+                                 TransportChannelImpl* impl);
+
+  rtc::Thread* const worker_thread_;
+  const std::string sid_;
+  const std::string content_name_;
+  rtc::scoped_refptr<TransportWrapper> transport_;
+  bool connecting_;
+  bool negotiated_;
+  ChannelMap channels_;
+  Candidates sent_candidates_;
+  Candidates unsent_candidates_;
+  bool candidates_allocated_;
+  bool local_description_set_;
+  bool remote_description_set_;
+};
+
+typedef std::map<std::string, TransportProxy*> TransportMap;
+
+// Statistics for all the transports of this session.
+typedef std::map<std::string, TransportStats> TransportStatsMap;
+typedef std::map<std::string, std::string> ProxyTransportMap;
+
+struct SessionStats {
+  ProxyTransportMap proxy_to_transport;
+  TransportStatsMap transport_stats;
+};
+
+// A BaseSession manages general session state. This includes negotiation
+// of both the application-level and network-level protocols:  the former
+// defines what will be sent and the latter defines how it will be sent.  Each
+// network-level protocol is represented by a Transport object.  Each Transport
+// participates in the network-level negotiation.  The individual streams of
+// packets are represented by TransportChannels.  The application-level protocol
+// is represented by SessionDecription objects.
+class BaseSession : public sigslot::has_slots<>,
+                    public rtc::MessageHandler {
+ public:
+  enum {
+    MSG_TIMEOUT = 0,
+    MSG_ERROR,
+    MSG_STATE,
+  };
+
+  enum State {
+    STATE_INIT = 0,
+    STATE_SENTINITIATE,       // sent initiate, waiting for Accept or Reject
+    STATE_RECEIVEDINITIATE,   // received an initiate. Call Accept or Reject
+    STATE_SENTPRACCEPT,       // sent provisional Accept
+    STATE_SENTACCEPT,         // sent accept. begin connecting transport
+    STATE_RECEIVEDPRACCEPT,   // received provisional Accept, waiting for Accept
+    STATE_RECEIVEDACCEPT,     // received accept. begin connecting transport
+    STATE_SENTMODIFY,         // sent modify, waiting for Accept or Reject
+    STATE_RECEIVEDMODIFY,     // received modify, call Accept or Reject
+    STATE_SENTREJECT,         // sent reject after receiving initiate
+    STATE_RECEIVEDREJECT,     // received reject after sending initiate
+    STATE_SENTREDIRECT,       // sent direct after receiving initiate
+    STATE_SENTTERMINATE,      // sent terminate (any time / either side)
+    STATE_RECEIVEDTERMINATE,  // received terminate (any time / either side)
+    STATE_INPROGRESS,         // session accepted and in progress
+    STATE_DEINIT,             // session is being destroyed
+  };
+
+  enum Error {
+    ERROR_NONE = 0,       // no error
+    ERROR_TIME = 1,       // no response to signaling
+    ERROR_RESPONSE = 2,   // error during signaling
+    ERROR_NETWORK = 3,    // network error, could not allocate network resources
+    ERROR_CONTENT = 4,    // channel errors in SetLocalContent/SetRemoteContent
+    ERROR_TRANSPORT = 5,  // transport error of some kind
+  };
+
+  // Convert State to a readable string.
+  static std::string StateToString(State state);
+
+  BaseSession(rtc::Thread* signaling_thread,
+              rtc::Thread* worker_thread,
+              PortAllocator* port_allocator,
+              const std::string& sid,
+              const std::string& content_type,
+              bool initiator);
+  virtual ~BaseSession();
+
+  // These are const to allow them to be called from const methods.
+  rtc::Thread* signaling_thread() const { return signaling_thread_; }
+  rtc::Thread* worker_thread() const { return worker_thread_; }
+  PortAllocator* port_allocator() const { return port_allocator_; }
+
+  // The ID of this session.
+  const std::string& id() const { return sid_; }
+
+  // TODO(juberti): This data is largely redundant, as it can now be obtained
+  // from local/remote_description(). Remove these functions and members.
+  // Returns the XML namespace identifying the type of this session.
+  const std::string& content_type() const { return content_type_; }
+  // Returns the XML namespace identifying the transport used for this session.
+  const std::string& transport_type() const { return transport_type_; }
+
+  // Indicates whether we initiated this session.
+  bool initiator() const { return initiator_; }
+
+  // Returns the application-level description given by our client.
+  // If we are the recipient, this will be NULL until we send an accept.
+  const SessionDescription* local_description() const;
+
+  // Returns the application-level description given by the other client.
+  // If we are the initiator, this will be NULL until we receive an accept.
+  const SessionDescription* remote_description() const;
+
+  SessionDescription* remote_description();
+
+  // Takes ownership of SessionDescription*
+  void set_local_description(const SessionDescription* sdesc);
+
+  // Takes ownership of SessionDescription*
+  void set_remote_description(SessionDescription* sdesc);
+
+  const SessionDescription* initiator_description() const;
+
+  // Returns the current state of the session.  See the enum above for details.
+  // Each time the state changes, we will fire this signal.
+  State state() const { return state_; }
+  sigslot::signal2<BaseSession* , State> SignalState;
+
+  // Returns the last error in the session.  See the enum above for details.
+  // Each time the an error occurs, we will fire this signal.
+  Error error() const { return error_; }
+  const std::string& error_desc() const { return error_desc_; }
+  sigslot::signal2<BaseSession* , Error> SignalError;
+
+  // Updates the state, signaling if necessary.
+  virtual void SetState(State state);
+
+  // Updates the error state, signaling if necessary.
+  // TODO(ronghuawu): remove the SetError method that doesn't take |error_desc|.
+  virtual void SetError(Error error, const std::string& error_desc);
+
+  // Fired when the remote description is updated, with the updated
+  // contents.
+  sigslot::signal2<BaseSession* , const ContentInfos&>
+      SignalRemoteDescriptionUpdate;
+
+  // Fired when SetState is called (regardless if there's a state change), which
+  // indicates the session description might have be updated.
+  sigslot::signal2<BaseSession*, ContentAction> SignalNewLocalDescription;
+
+  // Fired when SetState is called (regardless if there's a state change), which
+  // indicates the session description might have be updated.
+  sigslot::signal2<BaseSession*, ContentAction> SignalNewRemoteDescription;
+
+  // Returns the transport that has been negotiated or NULL if
+  // negotiation is still in progress.
+  virtual Transport* GetTransport(const std::string& content_name);
+
+  // Creates a new channel with the given names.  This method may be called
+  // immediately after creating the session.  However, the actual
+  // implementation may not be fixed until transport negotiation completes.
+  // This will usually be called from the worker thread, but that
+  // shouldn't be an issue since the main thread will be blocked in
+  // Send when doing so.
+  virtual TransportChannel* CreateChannel(const std::string& content_name,
+                                          const std::string& channel_name,
+                                          int component);
+
+  // Returns the channel with the given names.
+  virtual TransportChannel* GetChannel(const std::string& content_name,
+                                       int component);
+
+  // Destroys the channel with the given names.
+  // This will usually be called from the worker thread, but that
+  // shouldn't be an issue since the main thread will be blocked in
+  // Send when doing so.
+  virtual void DestroyChannel(const std::string& content_name,
+                              int component);
+
+  // Returns stats for all channels of all transports.
+  // This avoids exposing the internal structures used to track them.
+  virtual bool GetStats(SessionStats* stats);
+
+  rtc::SSLIdentity* identity() { return identity_; }
+
+ protected:
+  // Specifies the identity to use in this session.
+  bool SetIdentity(rtc::SSLIdentity* identity);
+
+  bool PushdownTransportDescription(ContentSource source,
+                                    ContentAction action,
+                                    std::string* error_desc);
+  void set_initiator(bool initiator) { initiator_ = initiator; }
+
+  const TransportMap& transport_proxies() const { return transports_; }
+  // Get a TransportProxy by content_name or transport. NULL if not found.
+  TransportProxy* GetTransportProxy(const std::string& content_name);
+  TransportProxy* GetTransportProxy(const Transport* transport);
+  TransportProxy* GetFirstTransportProxy();
+  void DestroyTransportProxy(const std::string& content_name);
+  // TransportProxy is owned by session.  Return proxy just for convenience.
+  TransportProxy* GetOrCreateTransportProxy(const std::string& content_name);
+  // Creates the actual transport object. Overridable for testing.
+  virtual Transport* CreateTransport(const std::string& content_name);
+
+  void OnSignalingReady();
+  void SpeculativelyConnectAllTransportChannels();
+  // Helper method to provide remote candidates to the transport.
+  bool OnRemoteCandidates(const std::string& content_name,
+                          const Candidates& candidates,
+                          std::string* error);
+
+  // This method will mux transport channels by content_name.
+  // First content is used for muxing.
+  bool MaybeEnableMuxingSupport();
+
+  // Called when a transport requests signaling.
+  virtual void OnTransportRequestSignaling(Transport* transport) {
+  }
+
+  // Called when the first channel of a transport begins connecting.  We use
+  // this to start a timer, to make sure that the connection completes in a
+  // reasonable amount of time.
+  virtual void OnTransportConnecting(Transport* transport) {
+  }
+
+  // Called when a transport changes its writable state.  We track this to make
+  // sure that the transport becomes writable within a reasonable amount of
+  // time.  If this does not occur, we signal an error.
+  virtual void OnTransportWritable(Transport* transport) {
+  }
+  virtual void OnTransportReadable(Transport* transport) {
+  }
+
+  // Called when a transport has found its steady-state connections.
+  virtual void OnTransportCompleted(Transport* transport) {
+  }
+
+  // Called when a transport has failed permanently.
+  virtual void OnTransportFailed(Transport* transport) {
+  }
+
+  // Called when a transport signals that it has new candidates.
+  virtual void OnTransportProxyCandidatesReady(TransportProxy* proxy,
+                                               const Candidates& candidates) {
+  }
+
+  // Called when a transport signals that it found an error in an incoming
+  // message.
+  virtual void OnTransportSendError(Transport* transport,
+                                    const buzz::XmlElement* stanza,
+                                    const buzz::QName& name,
+                                    const std::string& type,
+                                    const std::string& text,
+                                    const buzz::XmlElement* extra_info) {
+  }
+
+  virtual void OnTransportRouteChange(
+      Transport* transport,
+      int component,
+      const cricket::Candidate& remote_candidate) {
+  }
+
+  virtual void OnTransportCandidatesAllocationDone(Transport* transport);
+
+  // Called when all transport channels allocated required candidates.
+  // This method should be used as an indication of candidates gathering process
+  // is completed and application can now send local candidates list to remote.
+  virtual void OnCandidatesAllocationDone() {
+  }
+
+  // Handles the ice role change callback from Transport. This must be
+  // propagated to all the transports.
+  virtual void OnRoleConflict();
+
+  // Handles messages posted to us.
+  virtual void OnMessage(rtc::Message *pmsg);
+
+ protected:
+  State state_;
+  Error error_;
+  std::string error_desc_;
+
+ private:
+  // Helper methods to push local and remote transport descriptions.
+  bool PushdownLocalTransportDescription(
+      const SessionDescription* sdesc, ContentAction action,
+      std::string* error_desc);
+  bool PushdownRemoteTransportDescription(
+      const SessionDescription* sdesc, ContentAction action,
+      std::string* error_desc);
+
+  bool IsCandidateAllocationDone() const;
+  void MaybeCandidateAllocationDone();
+
+  // This method will delete the Transport and TransportChannelImpls and
+  // replace those with the selected Transport objects. Selection is done
+  // based on the content_name and in this case first MediaContent information
+  // is used for mux.
+  bool SetSelectedProxy(const std::string& content_name,
+                        const ContentGroup* muxed_group);
+  // Log session state.
+  void LogState(State old_state, State new_state);
+
+  // Returns true and the TransportInfo of the given |content_name|
+  // from |description|. Returns false if it's not available.
+  static bool GetTransportDescription(const SessionDescription* description,
+                                      const std::string& content_name,
+                                      TransportDescription* info);
+
+  // Fires the new description signal according to the current state.
+  void SignalNewDescription();
+
+  // Gets the ContentAction and ContentSource according to the session state.
+  bool GetContentAction(ContentAction* action, ContentSource* source);
+
+  rtc::Thread* const signaling_thread_;
+  rtc::Thread* const worker_thread_;
+  PortAllocator* const port_allocator_;
+  const std::string sid_;
+  const std::string content_type_;
+  const std::string transport_type_;
+  bool initiator_;
+  rtc::SSLIdentity* identity_;
+  rtc::scoped_ptr<const SessionDescription> local_description_;
+  rtc::scoped_ptr<SessionDescription> remote_description_;
+  uint64 ice_tiebreaker_;
+  // This flag will be set to true after the first role switch. This flag
+  // will enable us to stop any role switch during the call.
+  bool role_switch_;
+  TransportMap transports_;
+};
+
+// A specific Session created by the SessionManager, using XMPP for protocol.
+class Session : public BaseSession {
+ public:
+  // Returns the manager that created and owns this session.
+  SessionManager* session_manager() const { return session_manager_; }
+
+  // Returns the client that is handling the application data of this session.
+  SessionClient* client() const { return client_; }
+
+    // Returns the JID of this client.
+  const std::string& local_name() const { return local_name_; }
+
+  // Returns the JID of the other peer in this session.
+  const std::string& remote_name() const { return remote_name_; }
+
+  // Set the JID of the other peer in this session.
+  // Typically the remote_name_ is set when the session is initiated.
+  // However, sometimes (e.g when a proxy is used) the peer name is
+  // known after the BaseSession has been initiated and it must be updated
+  // explicitly.
+  void set_remote_name(const std::string& name) { remote_name_ = name; }
+
+  // Set the JID of the initiator of this session. Allows for the overriding
+  // of the initiator to be a third-party, eg. the MUC JID when creating p2p
+  // sessions.
+  void set_initiator_name(const std::string& name) { initiator_name_ = name; }
+
+  // Indicates the JID of the entity who initiated this session.
+  // In special cases, may be different than both local_name and remote_name.
+  const std::string& initiator_name() const { return initiator_name_; }
+
+  SignalingProtocol current_protocol() const { return current_protocol_; }
+
+  void set_current_protocol(SignalingProtocol protocol) {
+    current_protocol_ = protocol;
+  }
+
+  // Updates the error state, signaling if necessary.
+  virtual void SetError(Error error, const std::string& error_desc);
+
+  // When the session needs to send signaling messages, it beings by requesting
+  // signaling.  The client should handle this by calling OnSignalingReady once
+  // it is ready to send the messages.
+  // (These are called only by SessionManager.)
+  sigslot::signal1<Session*> SignalRequestSignaling;
+  void OnSignalingReady() { BaseSession::OnSignalingReady(); }
+
+  // Takes ownership of session description.
+  // TODO: Add an error argument to pass back to the caller.
+  bool Initiate(const std::string& to,
+                const SessionDescription* sdesc);
+
+  // When we receive an initiate, we create a session in the
+  // RECEIVEDINITIATE state and respond by accepting or rejecting.
+  // Takes ownership of session description.
+  // TODO: Add an error argument to pass back to the caller.
+  bool Accept(const SessionDescription* sdesc);
+  bool Reject(const std::string& reason);
+  bool Terminate() {
+    return TerminateWithReason(STR_TERMINATE_SUCCESS);
+  }
+  bool TerminateWithReason(const std::string& reason);
+  // Fired whenever we receive a terminate message along with a reason
+  sigslot::signal2<Session*, const std::string&> SignalReceivedTerminateReason;
+
+  // The two clients in the session may also send one another
+  // arbitrary XML messages, which are called "info" messages. Sending
+  // takes ownership of the given elements.  The signal does not; the
+  // parent element will be deleted after the signal.
+  bool SendInfoMessage(const XmlElements& elems,
+                       const std::string& remote_name);
+  bool SendDescriptionInfoMessage(const ContentInfos& contents);
+  sigslot::signal2<Session*, const buzz::XmlElement*> SignalInfoMessage;
+
+ private:
+  // Creates or destroys a session.  (These are called only SessionManager.)
+  Session(SessionManager *session_manager,
+          const std::string& local_name, const std::string& initiator_name,
+          const std::string& sid, const std::string& content_type,
+          SessionClient* client);
+  ~Session();
+  // For each transport info, create a transport proxy.  Can fail for
+  // incompatible transport types.
+  bool CreateTransportProxies(const TransportInfos& tinfos,
+                              SessionError* error);
+  bool OnRemoteCandidates(const TransportInfos& tinfos,
+                          ParseError* error);
+  // Returns a TransportInfo without candidates for each content name.
+  // Uses the transport_type_ of the session.
+  TransportInfos GetEmptyTransportInfos(const ContentInfos& contents) const;
+
+    // Maps passed to serialization functions.
+  TransportParserMap GetTransportParsers();
+  ContentParserMap GetContentParsers();
+  CandidateTranslatorMap GetCandidateTranslators();
+
+  virtual void OnTransportRequestSignaling(Transport* transport);
+  virtual void OnTransportConnecting(Transport* transport);
+  virtual void OnTransportWritable(Transport* transport);
+  virtual void OnTransportProxyCandidatesReady(TransportProxy* proxy,
+                                               const Candidates& candidates);
+  virtual void OnTransportSendError(Transport* transport,
+                                    const buzz::XmlElement* stanza,
+                                    const buzz::QName& name,
+                                    const std::string& type,
+                                    const std::string& text,
+                                    const buzz::XmlElement* extra_info);
+  virtual void OnMessage(rtc::Message *pmsg);
+
+  // Send various kinds of session messages.
+  bool SendInitiateMessage(const SessionDescription* sdesc,
+                           SessionError* error);
+  bool SendAcceptMessage(const SessionDescription* sdesc, SessionError* error);
+  bool SendRejectMessage(const std::string& reason, SessionError* error);
+  bool SendTerminateMessage(const std::string& reason, SessionError* error);
+  bool SendTransportInfoMessage(const TransportInfo& tinfo,
+                                SessionError* error);
+  bool SendTransportInfoMessage(const TransportProxy* transproxy,
+                                const Candidates& candidates,
+                                SessionError* error);
+
+  bool ResendAllTransportInfoMessages(SessionError* error);
+  bool SendAllUnsentTransportInfoMessages(SessionError* error);
+
+  // All versions of SendMessage send a message of the given type to
+  // the other client.  Can pass either a set of elements or an
+  // "action", which must have a WriteSessionAction method to go along
+  // with it.  Sending with an action supports sending a "hybrid"
+  // message.  Sending with elements must be sent as Jingle or Gingle.
+
+  // When passing elems, must be either Jingle or Gingle protocol.
+  // Takes ownership of action_elems.
+  bool SendMessage(ActionType type, const XmlElements& action_elems,
+                   SessionError* error);
+  // Sends a messge, but overrides the remote name.
+  bool SendMessage(ActionType type, const XmlElements& action_elems,
+                   const std::string& remote_name,
+                   SessionError* error);
+  // When passing an action, may be Hybrid protocol.
+  template <typename Action>
+  bool SendMessage(ActionType type, const Action& action,
+                   SessionError* error);
+
+  // Helper methods to write the session message stanza.
+  template <typename Action>
+  bool WriteActionMessage(ActionType type, const Action& action,
+                          buzz::XmlElement* stanza, WriteError* error);
+  template <typename Action>
+  bool WriteActionMessage(SignalingProtocol protocol,
+                          ActionType type, const Action& action,
+                          buzz::XmlElement* stanza, WriteError* error);
+
+  // Sending messages in hybrid form requires being able to write them
+  // on a per-protocol basis with a common method signature, which all
+  // of these have.
+  bool WriteSessionAction(SignalingProtocol protocol,
+                          const SessionInitiate& init,
+                          XmlElements* elems, WriteError* error);
+  bool WriteSessionAction(SignalingProtocol protocol,
+                          const TransportInfo& tinfo,
+                          XmlElements* elems, WriteError* error);
+  bool WriteSessionAction(SignalingProtocol protocol,
+                          const SessionTerminate& term,
+                          XmlElements* elems, WriteError* error);
+
+  // Sends a message back to the other client indicating that we have received
+  // and accepted their message.
+  void SendAcknowledgementMessage(const buzz::XmlElement* stanza);
+
+  // Once signaling is ready, the session will use this signal to request the
+  // sending of each message.  When messages are received by the other client,
+  // they should be handed to OnIncomingMessage.
+  // (These are called only by SessionManager.)
+  sigslot::signal2<Session* , const buzz::XmlElement*> SignalOutgoingMessage;
+  void OnIncomingMessage(const SessionMessage& msg);
+
+  void OnIncomingResponse(const buzz::XmlElement* orig_stanza,
+                          const buzz::XmlElement* response_stanza,
+                          const SessionMessage& msg);
+  void OnInitiateAcked();
+  void OnFailedSend(const buzz::XmlElement* orig_stanza,
+                    const buzz::XmlElement* error_stanza);
+
+  // Invoked when an error is found in an incoming message.  This is translated
+  // into the appropriate XMPP response by SessionManager.
+  sigslot::signal6<BaseSession*,
+                   const buzz::XmlElement*,
+                   const buzz::QName&,
+                   const std::string&,
+                   const std::string&,
+                   const buzz::XmlElement*> SignalErrorMessage;
+
+  // Handlers for the various types of messages.  These functions may take
+  // pointers to the whole stanza or to just the session element.
+  bool OnInitiateMessage(const SessionMessage& msg, MessageError* error);
+  bool OnAcceptMessage(const SessionMessage& msg, MessageError* error);
+  bool OnRejectMessage(const SessionMessage& msg, MessageError* error);
+  bool OnInfoMessage(const SessionMessage& msg);
+  bool OnTerminateMessage(const SessionMessage& msg, MessageError* error);
+  bool OnTransportInfoMessage(const SessionMessage& msg, MessageError* error);
+  bool OnTransportAcceptMessage(const SessionMessage& msg, MessageError* error);
+  bool OnDescriptionInfoMessage(const SessionMessage& msg, MessageError* error);
+  bool OnRedirectError(const SessionRedirect& redirect, SessionError* error);
+
+  // Verifies that we are in the appropriate state to receive this message.
+  bool CheckState(State state, MessageError* error);
+
+  SessionManager* session_manager_;
+  bool initiate_acked_;
+  std::string local_name_;
+  std::string initiator_name_;
+  std::string remote_name_;
+  SessionClient* client_;
+  TransportParser* transport_parser_;
+  // Keeps track of what protocol we are speaking.
+  SignalingProtocol current_protocol_;
+
+  friend class SessionManager;  // For access to constructor, destructor,
+                                // and signaling related methods.
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_SESSION_H_
diff --git a/webrtc/p2p/base/session_unittest.cc b/webrtc/p2p/base/session_unittest.cc
new file mode 100644
index 0000000..d6f94b2
--- /dev/null
+++ b/webrtc/p2p/base/session_unittest.cc
@@ -0,0 +1,2430 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <string.h>
+
+#include <deque>
+#include <map>
+#include <sstream>
+
+#include "webrtc/p2p/base/basicpacketsocketfactory.h"
+#include "webrtc/p2p/base/constants.h"
+#include "webrtc/p2p/base/p2ptransport.h"
+#include "webrtc/p2p/base/parsing.h"
+#include "webrtc/p2p/base/portallocator.h"
+#include "webrtc/p2p/base/relayport.h"
+#include "webrtc/p2p/base/relayserver.h"
+#include "webrtc/p2p/base/session.h"
+#include "webrtc/p2p/base/sessionclient.h"
+#include "webrtc/p2p/base/sessionmanager.h"
+#include "webrtc/p2p/base/stunport.h"
+#include "webrtc/p2p/base/stunserver.h"
+#include "webrtc/p2p/base/transportchannel.h"
+#include "webrtc/p2p/base/transportchannelproxy.h"
+#include "webrtc/p2p/base/udpport.h"
+#include "webrtc/libjingle/xmpp/constants.h"
+#include "webrtc/base/base64.h"
+#include "webrtc/base/common.h"
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/helpers.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/natserver.h"
+#include "webrtc/base/natsocketfactory.h"
+#include "webrtc/base/stringencode.h"
+
+using cricket::SignalingProtocol;
+using cricket::PROTOCOL_HYBRID;
+using cricket::PROTOCOL_JINGLE;
+using cricket::PROTOCOL_GINGLE;
+
+static const std::string kInitiator = "init@init.com";
+static const std::string kResponder = "resp@resp.com";
+// Expected from test random number generator.
+static const std::string kSessionId = "9254631414740579489";
+// TODO: When we need to test more than one transport type,
+// allow this to be injected like the content types are.
+static const std::string kTransportType = "http://www.google.com/transport/p2p";
+
+// Controls how long we wait for a session to send messages that we
+// expect, in milliseconds.  We put it high to avoid flaky tests.
+static const int kEventTimeout = 5000;
+
+static const int kNumPorts = 2;
+static const int kPort0 = 28653;
+static const int kPortStep = 5;
+
+int GetPort(int port_index) {
+  return kPort0 + (port_index * kPortStep);
+}
+
+std::string GetPortString(int port_index) {
+  return rtc::ToString(GetPort(port_index));
+}
+
+// Only works for port_index < 10, which is fine for our purposes.
+std::string GetUsername(int port_index) {
+  return "username" + std::string(8, rtc::ToString(port_index)[0]);
+}
+
+// Only works for port_index < 10, which is fine for our purposes.
+std::string GetPassword(int port_index) {
+  return "password" + std::string(8, rtc::ToString(port_index)[0]);
+}
+
+std::string IqAck(const std::string& id,
+                  const std::string& from,
+                  const std::string& to) {
+  return "<cli:iq"
+      " to=\"" + to + "\""
+      " id=\"" + id + "\""
+      " type=\"result\""
+      " from=\"" + from + "\""
+      " xmlns:cli=\"jabber:client\""
+      "/>";
+}
+
+std::string IqSet(const std::string& id,
+                  const std::string& from,
+                  const std::string& to,
+                  const std::string& content) {
+  return "<cli:iq"
+      " to=\"" + to + "\""
+      " type=\"set\""
+      " from=\"" + from + "\""
+      " id=\"" + id + "\""
+      " xmlns:cli=\"jabber:client\""
+      ">"
+      + content +
+      "</cli:iq>";
+}
+
+std::string IqError(const std::string& id,
+                    const std::string& from,
+                    const std::string& to,
+                    const std::string& content) {
+  return "<cli:error"
+      " to=\"" + to + "\""
+      " type=\"error\""
+      " from=\"" + from + "\""
+      " id=\"" + id + "\""
+      " xmlns:cli=\"jabber:client\""
+      ">"
+      + content +
+      "</cli:error>";
+}
+
+std::string GingleSessionXml(const std::string& type,
+                             const std::string& content) {
+  return "<session"
+      " xmlns=\"http://www.google.com/session\""
+      " type=\"" + type + "\""
+      " id=\"" + kSessionId + "\""
+      " initiator=\"" + kInitiator + "\""
+      ">"
+      + content +
+      "</session>";
+}
+
+std::string GingleDescriptionXml(const std::string& content_type) {
+  return "<description"
+      " xmlns=\"" + content_type + "\""
+      "/>";
+}
+
+std::string P2pCandidateXml(const std::string& name, int port_index) {
+  // Port will update the rtcp username by +1 on the last character. So we need
+  // to compensate here. See Port::username_fragment() for detail.
+  std::string username = GetUsername(port_index);
+  // TODO: Use the component id instead of the channel name to
+  // determinte if we need to covert the username here.
+  if (name == "rtcp" || name == "video_rtcp" || name == "chanb") {
+    char next_ch = username[username.size() - 1];
+    ASSERT(username.size() > 0);
+    rtc::Base64::GetNextBase64Char(next_ch, &next_ch);
+    username[username.size() - 1] = next_ch;
+  }
+  return "<candidate"
+      " name=\"" + name + "\""
+      " address=\"127.0.0.1\""
+      " port=\"" + GetPortString(port_index) + "\""
+      " preference=\"0.99\""
+      " username=\"" + username + "\""
+      " protocol=\"udp\""
+      " generation=\"0\""
+      " password=\"" + GetPassword(port_index) + "\""
+      " type=\"local\""
+      " network=\"network\""
+      "/>";
+}
+
+std::string JingleActionXml(const std::string& action,
+                            const std::string& content) {
+  return "<jingle"
+      " xmlns=\"urn:xmpp:jingle:1\""
+      " action=\"" + action + "\""
+      " sid=\"" + kSessionId + "\""
+      ">"
+      + content +
+      "</jingle>";
+}
+
+std::string JingleInitiateActionXml(const std::string& content) {
+  return "<jingle"
+      " xmlns=\"urn:xmpp:jingle:1\""
+      " action=\"session-initiate\""
+      " sid=\"" + kSessionId + "\""
+      " initiator=\"" + kInitiator + "\""
+      ">"
+      + content +
+      "</jingle>";
+}
+
+std::string JingleGroupInfoXml(const std::string& content_name_a,
+                               const std::string& content_name_b) {
+  std::string group_info = "<jin:group"
+      " type=\"BUNDLE\""
+      " xmlns:jin=\"google:jingle\""
+      ">";
+  if (!content_name_a.empty())
+    group_info += "<content name=\"" + content_name_a + "\""
+    "/>";
+  if (!content_name_b.empty())
+    group_info += "<content name=\"" + content_name_b + "\""
+    "/>";
+  group_info += "</jin:group>";
+  return group_info;
+}
+
+
+std::string JingleEmptyContentXml(const std::string& content_name,
+                                  const std::string& content_type,
+                                  const std::string& transport_type) {
+  return "<content"
+      " name=\"" + content_name + "\""
+      " creator=\"initiator\""
+      ">"
+      "<description"
+      " xmlns=\"" + content_type + "\""
+      "/>"
+      "<transport"
+      " xmlns=\"" + transport_type + "\""
+      "/>"
+      "</content>";
+}
+
+std::string JingleContentXml(const std::string& content_name,
+                             const std::string& content_type,
+                             const std::string& transport_type,
+                             const std::string& transport_main) {
+  std::string transport = transport_type.empty() ? "" :
+      "<transport"
+      " xmlns=\"" + transport_type + "\""
+      ">"
+      + transport_main +
+      "</transport>";
+
+  return"<content"
+      " name=\"" + content_name + "\""
+      " creator=\"initiator\""
+      ">"
+      "<description"
+      " xmlns=\"" + content_type + "\""
+      "/>"
+      + transport +
+      "</content>";
+}
+
+std::string JingleTransportContentXml(const std::string& content_name,
+                                      const std::string& transport_type,
+                                      const std::string& content) {
+  return "<content"
+      " name=\"" + content_name + "\""
+      " creator=\"initiator\""
+      ">"
+      "<transport"
+      " xmlns=\"" + transport_type + "\""
+      ">"
+      + content +
+      "</transport>"
+      "</content>";
+}
+
+std::string GingleInitiateXml(const std::string& content_type) {
+  return GingleSessionXml(
+      "initiate",
+      GingleDescriptionXml(content_type));
+}
+
+std::string JingleInitiateXml(const std::string& content_name_a,
+                              const std::string& content_type_a,
+                              const std::string& content_name_b,
+                              const std::string& content_type_b,
+                              bool bundle = false) {
+  std::string content_xml;
+  if (content_name_b.empty()) {
+    content_xml = JingleEmptyContentXml(
+        content_name_a, content_type_a, kTransportType);
+  } else {
+    content_xml = JingleEmptyContentXml(
+           content_name_a, content_type_a, kTransportType) +
+       JingleEmptyContentXml(
+           content_name_b, content_type_b, kTransportType);
+    if (bundle) {
+      content_xml += JingleGroupInfoXml(content_name_a, content_name_b);
+    }
+  }
+  return JingleInitiateActionXml(content_xml);
+}
+
+std::string GingleAcceptXml(const std::string& content_type) {
+  return GingleSessionXml(
+      "accept",
+      GingleDescriptionXml(content_type));
+}
+
+std::string JingleAcceptXml(const std::string& content_name_a,
+                            const std::string& content_type_a,
+                            const std::string& content_name_b,
+                            const std::string& content_type_b,
+                            bool bundle = false) {
+  std::string content_xml;
+  if (content_name_b.empty()) {
+    content_xml = JingleEmptyContentXml(
+        content_name_a, content_type_a, kTransportType);
+  } else {
+    content_xml = JingleEmptyContentXml(
+        content_name_a, content_type_a, kTransportType) +
+        JingleEmptyContentXml(
+            content_name_b, content_type_b, kTransportType);
+  }
+  if (bundle) {
+    content_xml += JingleGroupInfoXml(content_name_a, content_name_b);
+  }
+
+  return JingleActionXml("session-accept", content_xml);
+}
+
+std::string Gingle2CandidatesXml(const std::string& channel_name,
+                                 int port_index0,
+                                 int port_index1) {
+  return GingleSessionXml(
+      "candidates",
+      P2pCandidateXml(channel_name, port_index0) +
+      P2pCandidateXml(channel_name, port_index1));
+}
+
+std::string Gingle4CandidatesXml(const std::string& channel_name_a,
+                                 int port_index0,
+                                 int port_index1,
+                                 const std::string& channel_name_b,
+                                 int port_index2,
+                                 int port_index3) {
+  return GingleSessionXml(
+      "candidates",
+      P2pCandidateXml(channel_name_a, port_index0) +
+      P2pCandidateXml(channel_name_a, port_index1) +
+      P2pCandidateXml(channel_name_b, port_index2) +
+      P2pCandidateXml(channel_name_b, port_index3));
+}
+
+std::string Jingle2TransportInfoXml(const std::string& content_name,
+                                    const std::string& channel_name,
+                                    int port_index0,
+                                    int port_index1) {
+  return JingleActionXml(
+      "transport-info",
+      JingleTransportContentXml(
+          content_name, kTransportType,
+          P2pCandidateXml(channel_name, port_index0) +
+          P2pCandidateXml(channel_name, port_index1)));
+}
+
+std::string Jingle4TransportInfoXml(const std::string& content_name,
+                                    const std::string& channel_name_a,
+                                    int port_index0,
+                                    int port_index1,
+                                    const std::string& channel_name_b,
+                                    int port_index2,
+                                    int port_index3) {
+  return JingleActionXml(
+      "transport-info",
+      JingleTransportContentXml(
+          content_name, kTransportType,
+          P2pCandidateXml(channel_name_a, port_index0) +
+          P2pCandidateXml(channel_name_a, port_index1) +
+          P2pCandidateXml(channel_name_b, port_index2) +
+          P2pCandidateXml(channel_name_b, port_index3)));
+}
+
+std::string JingleDescriptionInfoXml(const std::string& content_name,
+                                     const std::string& content_type) {
+  return JingleActionXml(
+      "description-info",
+      JingleContentXml(content_name, content_type, "", ""));
+}
+
+std::string GingleRejectXml(const std::string& reason) {
+  return GingleSessionXml(
+      "reject",
+      "<" + reason + "/>");
+}
+
+std::string JingleTerminateXml(const std::string& reason) {
+    return JingleActionXml(
+        "session-terminate",
+        "<reason><" + reason + "/></reason>");
+}
+
+std::string GingleTerminateXml(const std::string& reason) {
+  return GingleSessionXml(
+      "terminate",
+      "<" + reason + "/>");
+}
+
+std::string GingleRedirectXml(const std::string& intitiate,
+                              const std::string& target) {
+  return intitiate +
+    "<error code=\"302\" type=\"modify\">"
+    "<redirect xmlns=\"http://www.google.com/session\">"
+    "xmpp:" + target +
+    "</redirect>"
+    "</error>";
+}
+
+std::string JingleRedirectXml(const std::string& intitiate,
+                              const std::string& target) {
+  return intitiate +
+    "<error code=\"302\" type=\"modify\">"
+    "<redirect xmlns=\"urn:ietf:params:xml:ns:xmpp-stanzas\">"
+    "xmpp:" + target +
+    "</redirect>"
+    "</error>";
+}
+
+std::string InitiateXml(SignalingProtocol protocol,
+                        const std::string& gingle_content_type,
+                        const std::string& content_name_a,
+                        const std::string& content_type_a,
+                        const std::string& content_name_b,
+                        const std::string& content_type_b,
+                        bool bundle = false) {
+  switch (protocol) {
+    case PROTOCOL_JINGLE:
+      return JingleInitiateXml(content_name_a, content_type_a,
+                               content_name_b, content_type_b,
+                               bundle);
+    case PROTOCOL_GINGLE:
+      return GingleInitiateXml(gingle_content_type);
+    case PROTOCOL_HYBRID:
+      return JingleInitiateXml(content_name_a, content_type_a,
+                               content_name_b, content_type_b) +
+          GingleInitiateXml(gingle_content_type);
+  }
+  return "";
+}
+
+std::string InitiateXml(SignalingProtocol protocol,
+                        const std::string& content_name,
+                        const std::string& content_type) {
+  return InitiateXml(protocol,
+                     content_type,
+                     content_name, content_type,
+                     "", "");
+}
+
+std::string AcceptXml(SignalingProtocol protocol,
+                      const std::string& gingle_content_type,
+                      const std::string& content_name_a,
+                      const std::string& content_type_a,
+                      const std::string& content_name_b,
+                      const std::string& content_type_b,
+                      bool bundle = false) {
+  switch (protocol) {
+    case PROTOCOL_JINGLE:
+      return JingleAcceptXml(content_name_a, content_type_a,
+                             content_name_b, content_type_b, bundle);
+    case PROTOCOL_GINGLE:
+      return GingleAcceptXml(gingle_content_type);
+    case PROTOCOL_HYBRID:
+      return
+          JingleAcceptXml(content_name_a, content_type_a,
+                          content_name_b, content_type_b) +
+          GingleAcceptXml(gingle_content_type);
+  }
+  return "";
+}
+
+
+std::string AcceptXml(SignalingProtocol protocol,
+                      const std::string& content_name,
+                      const std::string& content_type,
+                      bool bundle = false) {
+  return AcceptXml(protocol,
+                   content_type,
+                   content_name, content_type,
+                   "", "");
+}
+
+std::string TransportInfo2Xml(SignalingProtocol protocol,
+                              const std::string& content_name,
+                              const std::string& channel_name,
+                              int port_index0,
+                              int port_index1) {
+  switch (protocol) {
+    case PROTOCOL_JINGLE:
+      return Jingle2TransportInfoXml(
+          content_name,
+          channel_name, port_index0, port_index1);
+    case PROTOCOL_GINGLE:
+      return Gingle2CandidatesXml(
+          channel_name, port_index0, port_index1);
+    case PROTOCOL_HYBRID:
+      return
+          Jingle2TransportInfoXml(
+              content_name,
+              channel_name, port_index0, port_index1) +
+          Gingle2CandidatesXml(
+              channel_name, port_index0, port_index1);
+  }
+  return "";
+}
+
+std::string TransportInfo4Xml(SignalingProtocol protocol,
+                              const std::string& content_name,
+                              const std::string& channel_name_a,
+                              int port_index0,
+                              int port_index1,
+                              const std::string& channel_name_b,
+                              int port_index2,
+                              int port_index3) {
+  switch (protocol) {
+    case PROTOCOL_JINGLE:
+      return Jingle4TransportInfoXml(
+          content_name,
+          channel_name_a, port_index0, port_index1,
+          channel_name_b, port_index2, port_index3);
+    case PROTOCOL_GINGLE:
+      return Gingle4CandidatesXml(
+          channel_name_a, port_index0, port_index1,
+          channel_name_b, port_index2, port_index3);
+    case PROTOCOL_HYBRID:
+      return
+          Jingle4TransportInfoXml(
+              content_name,
+              channel_name_a, port_index0, port_index1,
+              channel_name_b, port_index2, port_index3) +
+          Gingle4CandidatesXml(
+              channel_name_a, port_index0, port_index1,
+              channel_name_b, port_index2, port_index3);
+  }
+  return "";
+}
+
+std::string RejectXml(SignalingProtocol protocol,
+                      const std::string& reason) {
+  switch (protocol) {
+    case PROTOCOL_JINGLE:
+      return JingleTerminateXml(reason);
+    case PROTOCOL_GINGLE:
+      return GingleRejectXml(reason);
+    case PROTOCOL_HYBRID:
+      return JingleTerminateXml(reason) +
+          GingleRejectXml(reason);
+  }
+  return "";
+}
+
+std::string TerminateXml(SignalingProtocol protocol,
+                         const std::string& reason) {
+  switch (protocol) {
+    case PROTOCOL_JINGLE:
+      return JingleTerminateXml(reason);
+    case PROTOCOL_GINGLE:
+      return GingleTerminateXml(reason);
+    case PROTOCOL_HYBRID:
+      return JingleTerminateXml(reason) +
+          GingleTerminateXml(reason);
+  }
+  return "";
+}
+
+std::string RedirectXml(SignalingProtocol protocol,
+                        const std::string& initiate,
+                        const std::string& target) {
+  switch (protocol) {
+    case PROTOCOL_JINGLE:
+      return JingleRedirectXml(initiate, target);
+    case PROTOCOL_GINGLE:
+      return GingleRedirectXml(initiate, target);
+    default:
+      break;
+  }
+  return "";
+}
+
+// TODO: Break out and join with fakeportallocator.h
+class TestPortAllocatorSession : public cricket::PortAllocatorSession {
+ public:
+  TestPortAllocatorSession(const std::string& content_name,
+                           int component,
+                           const std::string& ice_ufrag,
+                           const std::string& ice_pwd,
+                           const int port_offset)
+      : PortAllocatorSession(content_name, component, ice_ufrag, ice_pwd, 0),
+        port_offset_(port_offset),
+        ports_(kNumPorts),
+        address_("127.0.0.1", 0),
+        network_("network", "unittest",
+                 rtc::IPAddress(INADDR_LOOPBACK), 8),
+        socket_factory_(rtc::Thread::Current()),
+        running_(false) {
+    network_.AddIP(address_.ipaddr());
+  }
+
+  ~TestPortAllocatorSession() {
+    for (size_t i = 0; i < ports_.size(); i++)
+      delete ports_[i];
+  }
+
+  virtual void StartGettingPorts() {
+    for (int i = 0; i < kNumPorts; i++) {
+      int index = port_offset_ + i;
+      ports_[i] = cricket::UDPPort::Create(
+          rtc::Thread::Current(), &socket_factory_,
+          &network_, address_.ipaddr(), GetPort(index), GetPort(index),
+          GetUsername(index), GetPassword(index));
+      AddPort(ports_[i]);
+    }
+    running_ = true;
+  }
+
+  virtual void StopGettingPorts() { running_ = false; }
+  virtual bool IsGettingPorts() { return running_; }
+
+  void AddPort(cricket::Port* port) {
+    port->set_component(component_);
+    port->set_generation(0);
+    port->SignalDestroyed.connect(
+        this, &TestPortAllocatorSession::OnPortDestroyed);
+    port->SignalPortComplete.connect(
+        this, &TestPortAllocatorSession::OnPortComplete);
+    port->PrepareAddress();
+    SignalPortReady(this, port);
+  }
+
+  void OnPortDestroyed(cricket::PortInterface* port) {
+    for (size_t i = 0; i < ports_.size(); i++) {
+      if (ports_[i] == port)
+        ports_[i] = NULL;
+    }
+  }
+
+  void OnPortComplete(cricket::Port* port) {
+    SignalCandidatesReady(this, port->Candidates());
+  }
+
+ private:
+  int port_offset_;
+  std::vector<cricket::Port*> ports_;
+  rtc::SocketAddress address_;
+  rtc::Network network_;
+  rtc::BasicPacketSocketFactory socket_factory_;
+  bool running_;
+};
+
+class TestPortAllocator : public cricket::PortAllocator {
+ public:
+  TestPortAllocator() : port_offset_(0) {}
+
+  virtual cricket::PortAllocatorSession*
+  CreateSessionInternal(
+                const std::string& content_name,
+                int component,
+                const std::string& ice_ufrag,
+                const std::string& ice_pwd) {
+    port_offset_ += 2;
+    return new TestPortAllocatorSession(content_name, component,
+                                        ice_ufrag, ice_pwd, port_offset_ - 2);
+  }
+
+  int port_offset_;
+};
+
+class TestContentDescription : public cricket::ContentDescription {
+ public:
+  explicit TestContentDescription(const std::string& gingle_content_type,
+                                  const std::string& content_type)
+      : gingle_content_type(gingle_content_type),
+        content_type(content_type) {
+  }
+  virtual ContentDescription* Copy() const {
+    return new TestContentDescription(*this);
+  }
+
+  std::string gingle_content_type;
+  std::string content_type;
+};
+
+cricket::SessionDescription* NewTestSessionDescription(
+    const std::string gingle_content_type,
+    const std::string& content_name_a, const std::string& content_type_a,
+    const std::string& content_name_b, const std::string& content_type_b) {
+
+  cricket::SessionDescription* offer = new cricket::SessionDescription();
+  offer->AddContent(content_name_a, content_type_a,
+                    new TestContentDescription(gingle_content_type,
+                                               content_type_a));
+  cricket::TransportDescription desc(cricket::NS_GINGLE_P2P,
+                                     std::string(), std::string());
+  offer->AddTransportInfo(cricket::TransportInfo(content_name_a, desc));
+
+  if (content_name_a != content_name_b) {
+    offer->AddContent(content_name_b, content_type_b,
+                      new TestContentDescription(gingle_content_type,
+                                                 content_type_b));
+    offer->AddTransportInfo(cricket::TransportInfo(content_name_b, desc));
+  }
+  return offer;
+}
+
+cricket::SessionDescription* NewTestSessionDescription(
+    const std::string& content_name, const std::string& content_type) {
+
+  cricket::SessionDescription* offer = new cricket::SessionDescription();
+  offer->AddContent(content_name, content_type,
+                    new TestContentDescription(content_type,
+                                               content_type));
+  offer->AddTransportInfo(cricket::TransportInfo
+                          (content_name, cricket::TransportDescription(
+                          cricket::NS_GINGLE_P2P,
+                          std::string(), std::string())));
+  return offer;
+}
+
+struct TestSessionClient: public cricket::SessionClient,
+                          public sigslot::has_slots<> {
+ public:
+  TestSessionClient() {
+  }
+
+  ~TestSessionClient() {
+  }
+
+  virtual bool ParseContent(SignalingProtocol protocol,
+                            const buzz::XmlElement* elem,
+                            cricket::ContentDescription** content,
+                            cricket::ParseError* error) {
+    std::string content_type;
+    std::string gingle_content_type;
+    if (protocol == PROTOCOL_GINGLE) {
+      gingle_content_type = elem->Name().Namespace();
+    } else {
+      content_type = elem->Name().Namespace();
+    }
+
+    *content = new TestContentDescription(gingle_content_type, content_type);
+    return true;
+  }
+
+  virtual bool WriteContent(SignalingProtocol protocol,
+                            const cricket::ContentDescription* untyped_content,
+                            buzz::XmlElement** elem,
+                            cricket::WriteError* error) {
+    const TestContentDescription* content =
+        static_cast<const TestContentDescription*>(untyped_content);
+    std::string content_type = (protocol == PROTOCOL_GINGLE ?
+                                content->gingle_content_type :
+                                content->content_type);
+     *elem = new buzz::XmlElement(
+        buzz::QName(content_type, "description"), true);
+    return true;
+  }
+
+  void OnSessionCreate(cricket::Session* session, bool initiate) {
+  }
+
+  void OnSessionDestroy(cricket::Session* session) {
+  }
+};
+
+struct ChannelHandler : sigslot::has_slots<> {
+  explicit ChannelHandler(cricket::TransportChannel* p, const std::string& name)
+    : channel(p), last_readable(false), last_writable(false), data_count(0),
+      last_size(0), name(name) {
+    p->SignalReadableState.connect(this, &ChannelHandler::OnReadableState);
+    p->SignalWritableState.connect(this, &ChannelHandler::OnWritableState);
+    p->SignalReadPacket.connect(this, &ChannelHandler::OnReadPacket);
+  }
+
+  bool writable() const {
+    return last_writable && channel->writable();
+  }
+
+  bool readable() const {
+    return last_readable && channel->readable();
+  }
+
+  void OnReadableState(cricket::TransportChannel* p) {
+    EXPECT_EQ(channel, p);
+    last_readable = channel->readable();
+  }
+
+  void OnWritableState(cricket::TransportChannel* p) {
+    EXPECT_EQ(channel, p);
+    last_writable = channel->writable();
+  }
+
+  void OnReadPacket(cricket::TransportChannel* p, const char* buf,
+                    size_t size, const rtc::PacketTime& time, int flags) {
+    if (memcmp(buf, name.c_str(), name.size()) != 0)
+      return;  // drop packet if packet doesn't belong to this channel. This
+               // can happen when transport channels are muxed together.
+    buf += name.size();  // Remove channel name from the message.
+    size -= name.size();  // Decrement size by channel name string size.
+    EXPECT_EQ(channel, p);
+    EXPECT_LE(size, sizeof(last_data));
+    data_count += 1;
+    last_size = size;
+    memcpy(last_data, buf, size);
+  }
+
+  void Send(const char* data, size_t size) {
+    rtc::PacketOptions options;
+    std::string data_with_id(name);
+    data_with_id += data;
+    int result = channel->SendPacket(data_with_id.c_str(), data_with_id.size(),
+                                     options, 0);
+    EXPECT_EQ(static_cast<int>(data_with_id.size()), result);
+  }
+
+  cricket::TransportChannel* channel;
+  bool last_readable, last_writable;
+  int data_count;
+  char last_data[4096];
+  size_t last_size;
+  std::string name;
+};
+
+void PrintStanza(const std::string& message,
+                 const buzz::XmlElement* stanza) {
+  printf("%s: %s\n", message.c_str(), stanza->Str().c_str());
+}
+
+class TestClient : public sigslot::has_slots<> {
+ public:
+  // TODO: Add channel_component_a/b as inputs to the ctor.
+  TestClient(cricket::PortAllocator* port_allocator,
+             int* next_message_id,
+             const std::string& local_name,
+             SignalingProtocol start_protocol,
+             const std::string& content_type,
+             const std::string& content_name_a,
+             const std::string& channel_name_a,
+             const std::string& content_name_b,
+             const std::string& channel_name_b) {
+    Construct(port_allocator, next_message_id, local_name, start_protocol,
+              content_type, content_name_a, channel_name_a,
+              content_name_b, channel_name_b);
+  }
+
+  ~TestClient() {
+    if (session) {
+      session_manager->DestroySession(session);
+      EXPECT_EQ(1U, session_destroyed_count);
+    }
+    delete session_manager;
+    delete client;
+    for (std::deque<buzz::XmlElement*>::iterator it = sent_stanzas.begin();
+         it != sent_stanzas.end(); ++it) {
+      delete *it;
+    }
+  }
+
+  void Construct(cricket::PortAllocator* pa,
+                 int* message_id,
+                 const std::string& lname,
+                 SignalingProtocol protocol,
+                 const std::string& cont_type,
+                 const std::string& cont_name_a,
+                 const std::string& chan_name_a,
+                 const std::string& cont_name_b,
+                 const std::string& chan_name_b) {
+    port_allocator_ = pa;
+    next_message_id = message_id;
+    local_name = lname;
+    start_protocol = protocol;
+    content_type = cont_type;
+    content_name_a = cont_name_a;
+    channel_name_a = chan_name_a;
+    content_name_b = cont_name_b;
+    channel_name_b = chan_name_b;
+    session_created_count = 0;
+    session_destroyed_count = 0;
+    session_remote_description_update_count = 0;
+    new_local_description = false;
+    new_remote_description = false;
+    last_content_action = cricket::CA_OFFER;
+    last_content_source = cricket::CS_LOCAL;
+    session = NULL;
+    last_session_state = cricket::BaseSession::STATE_INIT;
+    blow_up_on_error = true;
+    error_count = 0;
+
+    session_manager = new cricket::SessionManager(port_allocator_);
+    session_manager->SignalSessionCreate.connect(
+        this, &TestClient::OnSessionCreate);
+    session_manager->SignalSessionDestroy.connect(
+        this, &TestClient::OnSessionDestroy);
+    session_manager->SignalOutgoingMessage.connect(
+        this, &TestClient::OnOutgoingMessage);
+
+    client = new TestSessionClient();
+    session_manager->AddClient(content_type, client);
+    EXPECT_EQ(client, session_manager->GetClient(content_type));
+  }
+
+  uint32 sent_stanza_count() const {
+    return static_cast<uint32>(sent_stanzas.size());
+  }
+
+  const buzz::XmlElement* stanza() const {
+    return last_expected_sent_stanza.get();
+  }
+
+  cricket::BaseSession::State session_state() const {
+    EXPECT_EQ(last_session_state, session->state());
+    return session->state();
+  }
+
+  void SetSessionState(cricket::BaseSession::State state) {
+    session->SetState(state);
+    EXPECT_EQ_WAIT(last_session_state, session->state(), kEventTimeout);
+  }
+
+  void CreateSession() {
+    session_manager->CreateSession(local_name, content_type);
+  }
+
+  void DeliverStanza(const buzz::XmlElement* stanza) {
+    session_manager->OnIncomingMessage(stanza);
+  }
+
+  void DeliverStanza(const std::string& str) {
+    buzz::XmlElement* stanza = buzz::XmlElement::ForStr(str);
+    session_manager->OnIncomingMessage(stanza);
+    delete stanza;
+  }
+
+  void DeliverAckToLastStanza() {
+    const buzz::XmlElement* orig_stanza = stanza();
+    const buzz::XmlElement* response_stanza =
+        buzz::XmlElement::ForStr(IqAck(orig_stanza->Attr(buzz::QN_IQ), "", ""));
+    session_manager->OnIncomingResponse(orig_stanza, response_stanza);
+    delete response_stanza;
+  }
+
+  void ExpectSentStanza(const std::string& expected) {
+    EXPECT_TRUE(!sent_stanzas.empty()) <<
+        "Found no stanza when expected " << expected;
+
+    last_expected_sent_stanza.reset(sent_stanzas.front());
+    sent_stanzas.pop_front();
+
+    std::string actual = last_expected_sent_stanza->Str();
+    EXPECT_EQ(expected, actual);
+  }
+
+  void SkipUnsentStanza() {
+    GetNextOutgoingMessageID();
+  }
+
+  bool HasTransport(const std::string& content_name) const {
+    ASSERT(session != NULL);
+    const cricket::Transport* transport = session->GetTransport(content_name);
+    return transport != NULL && (kTransportType == transport->type());
+  }
+
+  bool HasChannel(const std::string& content_name,
+                  int component) const {
+    ASSERT(session != NULL);
+    const cricket::TransportChannel* channel =
+        session->GetChannel(content_name, component);
+    return channel != NULL && (component == channel->component());
+  }
+
+  cricket::TransportChannel* GetChannel(const std::string& content_name,
+                                        int component) const {
+    ASSERT(session != NULL);
+    return session->GetChannel(content_name, component);
+  }
+
+  void OnSessionCreate(cricket::Session* created_session, bool initiate) {
+    session_created_count += 1;
+
+    session = created_session;
+    session->set_current_protocol(start_protocol);
+    session->SignalState.connect(this, &TestClient::OnSessionState);
+    session->SignalError.connect(this, &TestClient::OnSessionError);
+    session->SignalRemoteDescriptionUpdate.connect(
+        this, &TestClient::OnSessionRemoteDescriptionUpdate);
+    session->SignalNewLocalDescription.connect(
+        this, &TestClient::OnNewLocalDescription);
+    session->SignalNewRemoteDescription.connect(
+        this, &TestClient::OnNewRemoteDescription);
+
+    CreateChannels();
+  }
+
+  void OnSessionDestroy(cricket::Session *session) {
+    session_destroyed_count += 1;
+  }
+
+  void OnSessionState(cricket::BaseSession* session,
+                      cricket::BaseSession::State state) {
+    // EXPECT_EQ does not allow use of this, hence the tmp variable.
+    cricket::BaseSession* tmp = this->session;
+    EXPECT_EQ(tmp, session);
+    last_session_state = state;
+  }
+
+  void OnSessionError(cricket::BaseSession* session,
+                      cricket::BaseSession::Error error) {
+    // EXPECT_EQ does not allow use of this, hence the tmp variable.
+    cricket::BaseSession* tmp = this->session;
+    EXPECT_EQ(tmp, session);
+    if (blow_up_on_error) {
+      EXPECT_TRUE(false);
+    } else {
+      error_count++;
+    }
+  }
+
+  void OnSessionRemoteDescriptionUpdate(cricket::BaseSession* session,
+      const cricket::ContentInfos& contents) {
+    session_remote_description_update_count++;
+  }
+
+  void OnNewLocalDescription(cricket::BaseSession* session,
+                             cricket::ContentAction action) {
+    new_local_description = true;
+    last_content_action = action;
+    last_content_source = cricket::CS_LOCAL;
+  }
+
+  void OnNewRemoteDescription(cricket::BaseSession* session,
+                              cricket::ContentAction action) {
+    new_remote_description = true;
+    last_content_action = action;
+    last_content_source = cricket::CS_REMOTE;
+  }
+
+  void PrepareCandidates() {
+    session_manager->OnSignalingReady();
+  }
+
+  void OnOutgoingMessage(cricket::SessionManager* manager,
+                         const buzz::XmlElement* stanza) {
+    buzz::XmlElement* elem = new buzz::XmlElement(*stanza);
+    EXPECT_TRUE(elem->Name() == buzz::QN_IQ);
+    EXPECT_TRUE(elem->HasAttr(buzz::QN_TO));
+    EXPECT_FALSE(elem->HasAttr(buzz::QN_FROM));
+    EXPECT_TRUE(elem->HasAttr(buzz::QN_TYPE));
+    EXPECT_TRUE((elem->Attr(buzz::QN_TYPE) == "set") ||
+                (elem->Attr(buzz::QN_TYPE) == "result") ||
+                (elem->Attr(buzz::QN_TYPE) == "error"));
+
+    elem->SetAttr(buzz::QN_FROM, local_name);
+    if (elem->Attr(buzz::QN_TYPE) == "set") {
+      EXPECT_FALSE(elem->HasAttr(buzz::QN_ID));
+      elem->SetAttr(buzz::QN_ID, GetNextOutgoingMessageID());
+    }
+
+    // Uncommenting this is useful for debugging.
+    // PrintStanza("OutgoingMessage", elem);
+    sent_stanzas.push_back(elem);
+  }
+
+  std::string GetNextOutgoingMessageID() {
+    int message_id = (*next_message_id)++;
+    std::ostringstream ost;
+    ost << message_id;
+    return ost.str();
+  }
+
+  void CreateChannels() {
+    ASSERT(session != NULL);
+    // We either have a single content with multiple components (RTP/RTCP), or
+    // multiple contents with single components, but not both.
+    int component_a = 1;
+    int component_b = (content_name_a == content_name_b) ? 2 : 1;
+    chan_a.reset(new ChannelHandler(
+        session->CreateChannel(content_name_a, channel_name_a, component_a),
+        channel_name_a));
+    chan_b.reset(new ChannelHandler(
+        session->CreateChannel(content_name_b, channel_name_b, component_b),
+        channel_name_b));
+  }
+
+  int* next_message_id;
+  std::string local_name;
+  SignalingProtocol start_protocol;
+  std::string content_type;
+  std::string content_name_a;
+  std::string channel_name_a;
+  std::string content_name_b;
+  std::string channel_name_b;
+
+  uint32 session_created_count;
+  uint32 session_destroyed_count;
+  uint32 session_remote_description_update_count;
+  bool new_local_description;
+  bool new_remote_description;
+  cricket::ContentAction last_content_action;
+  cricket::ContentSource last_content_source;
+  std::deque<buzz::XmlElement*> sent_stanzas;
+  rtc::scoped_ptr<buzz::XmlElement> last_expected_sent_stanza;
+
+  cricket::SessionManager* session_manager;
+  TestSessionClient* client;
+  cricket::PortAllocator* port_allocator_;
+  cricket::Session* session;
+  cricket::BaseSession::State last_session_state;
+  rtc::scoped_ptr<ChannelHandler> chan_a;
+  rtc::scoped_ptr<ChannelHandler> chan_b;
+  bool blow_up_on_error;
+  int error_count;
+};
+
+class SessionTest : public testing::Test {
+ protected:
+  virtual void SetUp() {
+    // Seed needed for each test to satisfy expectations.
+    rtc::SetRandomTestMode(true);
+  }
+
+  virtual void TearDown() {
+    rtc::SetRandomTestMode(false);
+  }
+
+  // Tests sending data between two clients, over two channels.
+  void TestSendRecv(ChannelHandler* chan1a,
+                    ChannelHandler* chan1b,
+                    ChannelHandler* chan2a,
+                    ChannelHandler* chan2b) {
+    const char* dat1a = "spamspamspamspamspamspamspambakedbeansspam";
+    const char* dat2a = "mapssnaebdekabmapsmapsmapsmapsmapsmapsmaps";
+    const char* dat1b = "Lobster Thermidor a Crevette with a mornay sauce...";
+    const char* dat2b = "...ecuas yanrom a htiw etteverC a rodimrehT retsboL";
+
+    for (int i = 0; i < 20; i++) {
+      chan1a->Send(dat1a, strlen(dat1a));
+      chan1b->Send(dat1b, strlen(dat1b));
+      chan2a->Send(dat2a, strlen(dat2a));
+      chan2b->Send(dat2b, strlen(dat2b));
+
+      EXPECT_EQ_WAIT(i + 1, chan1a->data_count, kEventTimeout);
+      EXPECT_EQ_WAIT(i + 1, chan1b->data_count, kEventTimeout);
+      EXPECT_EQ_WAIT(i + 1, chan2a->data_count, kEventTimeout);
+      EXPECT_EQ_WAIT(i + 1, chan2b->data_count, kEventTimeout);
+
+      EXPECT_EQ(strlen(dat2a), chan1a->last_size);
+      EXPECT_EQ(strlen(dat2b), chan1b->last_size);
+      EXPECT_EQ(strlen(dat1a), chan2a->last_size);
+      EXPECT_EQ(strlen(dat1b), chan2b->last_size);
+
+      EXPECT_EQ(0, memcmp(chan1a->last_data, dat2a, strlen(dat2a)));
+      EXPECT_EQ(0, memcmp(chan1b->last_data, dat2b, strlen(dat2b)));
+      EXPECT_EQ(0, memcmp(chan2a->last_data, dat1a, strlen(dat1a)));
+      EXPECT_EQ(0, memcmp(chan2b->last_data, dat1b, strlen(dat1b)));
+    }
+  }
+
+  // Test an initiate from one client to another, each with
+  // independent initial protocols.  Checks for the correct initiates,
+  // candidates, and accept messages, and tests that working network
+  // channels are established.
+  void TestSession(SignalingProtocol initiator_protocol,
+                   SignalingProtocol responder_protocol,
+                   SignalingProtocol resulting_protocol,
+                   const std::string& gingle_content_type,
+                   const std::string& content_type,
+                   const std::string& content_name_a,
+                   const std::string& channel_name_a,
+                   const std::string& content_name_b,
+                   const std::string& channel_name_b,
+                   const std::string& initiate_xml,
+                   const std::string& transport_info_a_xml,
+                   const std::string& transport_info_b_xml,
+                   const std::string& transport_info_reply_a_xml,
+                   const std::string& transport_info_reply_b_xml,
+                   const std::string& accept_xml,
+                   bool bundle = false) {
+    rtc::scoped_ptr<cricket::PortAllocator> allocator(
+        new TestPortAllocator());
+    int next_message_id = 0;
+
+    rtc::scoped_ptr<TestClient> initiator(
+        new TestClient(allocator.get(), &next_message_id,
+                       kInitiator, initiator_protocol,
+                       content_type,
+                       content_name_a,  channel_name_a,
+                       content_name_b,  channel_name_b));
+    rtc::scoped_ptr<TestClient> responder(
+        new TestClient(allocator.get(), &next_message_id,
+                       kResponder, responder_protocol,
+                       content_type,
+                       content_name_a,  channel_name_a,
+                       content_name_b,  channel_name_b));
+
+    // Create Session and check channels and state.
+    initiator->CreateSession();
+    EXPECT_EQ(1U, initiator->session_created_count);
+    EXPECT_EQ(kSessionId, initiator->session->id());
+    EXPECT_EQ(initiator->session->local_name(), kInitiator);
+    EXPECT_EQ(cricket::BaseSession::STATE_INIT,
+              initiator->session_state());
+
+    // See comment in CreateChannels about how we choose component IDs.
+    int component_a = 1;
+    int component_b = (content_name_a == content_name_b) ? 2 : 1;
+    EXPECT_TRUE(initiator->HasTransport(content_name_a));
+    EXPECT_TRUE(initiator->HasChannel(content_name_a, component_a));
+    EXPECT_TRUE(initiator->HasTransport(content_name_b));
+    EXPECT_TRUE(initiator->HasChannel(content_name_b, component_b));
+
+    // Initiate and expect initiate message sent.
+    cricket::SessionDescription* offer = NewTestSessionDescription(
+        gingle_content_type,
+        content_name_a, content_type,
+        content_name_b, content_type);
+    if (bundle) {
+      cricket::ContentGroup group(cricket::GROUP_TYPE_BUNDLE);
+      group.AddContentName(content_name_a);
+      group.AddContentName(content_name_b);
+      EXPECT_TRUE(group.HasContentName(content_name_a));
+      EXPECT_TRUE(group.HasContentName(content_name_b));
+      offer->AddGroup(group);
+    }
+    EXPECT_TRUE(initiator->session->Initiate(kResponder, offer));
+    EXPECT_EQ(initiator->session->remote_name(), kResponder);
+    EXPECT_EQ(initiator->session->local_description(), offer);
+
+    EXPECT_TRUE_WAIT(initiator->sent_stanza_count() > 0, kEventTimeout);
+    EXPECT_EQ(cricket::BaseSession::STATE_SENTINITIATE,
+              initiator->session_state());
+
+    initiator->ExpectSentStanza(
+        IqSet("0", kInitiator, kResponder, initiate_xml));
+
+    // Deliver the initiate. Expect ack and session created with
+    // transports.
+    responder->DeliverStanza(initiator->stanza());
+    responder->ExpectSentStanza(
+        IqAck("0", kResponder, kInitiator));
+    EXPECT_EQ(0U, responder->sent_stanza_count());
+
+    EXPECT_EQ(1U, responder->session_created_count);
+    EXPECT_EQ(kSessionId, responder->session->id());
+    EXPECT_EQ(responder->session->local_name(), kResponder);
+    EXPECT_EQ(responder->session->remote_name(), kInitiator);
+    EXPECT_EQ(cricket::BaseSession::STATE_RECEIVEDINITIATE,
+              responder->session_state());
+
+    EXPECT_TRUE(responder->HasTransport(content_name_a));
+    EXPECT_TRUE(responder->HasChannel(content_name_a, component_a));
+    EXPECT_TRUE(responder->HasTransport(content_name_b));
+    EXPECT_TRUE(responder->HasChannel(content_name_b, component_b));
+
+    // Expect transport-info message from initiator.
+    // But don't send candidates until initiate ack is received.
+    initiator->PrepareCandidates();
+    WAIT(initiator->sent_stanza_count() > 0, 100);
+    EXPECT_EQ(0U, initiator->sent_stanza_count());
+    initiator->DeliverAckToLastStanza();
+    EXPECT_TRUE_WAIT(initiator->sent_stanza_count() > 0, kEventTimeout);
+    initiator->ExpectSentStanza(
+        IqSet("1", kInitiator, kResponder, transport_info_a_xml));
+
+    // Deliver transport-info and expect ack.
+    responder->DeliverStanza(initiator->stanza());
+    responder->ExpectSentStanza(
+        IqAck("1", kResponder, kInitiator));
+
+    if (!transport_info_b_xml.empty()) {
+      // Expect second transport-info message from initiator.
+      EXPECT_TRUE_WAIT(initiator->sent_stanza_count() > 0, kEventTimeout);
+      initiator->ExpectSentStanza(
+          IqSet("2", kInitiator, kResponder, transport_info_b_xml));
+      EXPECT_EQ(0U, initiator->sent_stanza_count());
+
+      // Deliver second transport-info message and expect ack.
+      responder->DeliverStanza(initiator->stanza());
+      responder->ExpectSentStanza(
+          IqAck("2", kResponder, kInitiator));
+    } else {
+      EXPECT_EQ(0U, initiator->sent_stanza_count());
+      EXPECT_EQ(0U, responder->sent_stanza_count());
+      initiator->SkipUnsentStanza();
+    }
+
+    // Expect reply transport-info message from responder.
+    responder->PrepareCandidates();
+    EXPECT_TRUE_WAIT(responder->sent_stanza_count() > 0, kEventTimeout);
+    responder->ExpectSentStanza(
+        IqSet("3", kResponder, kInitiator, transport_info_reply_a_xml));
+
+    // Deliver reply transport-info and expect ack.
+    initiator->DeliverStanza(responder->stanza());
+    initiator->ExpectSentStanza(
+        IqAck("3", kInitiator, kResponder));
+
+    if (!transport_info_reply_b_xml.empty()) {
+      // Expect second reply transport-info message from responder.
+      EXPECT_TRUE_WAIT(responder->sent_stanza_count() > 0, kEventTimeout);
+      responder->ExpectSentStanza(
+          IqSet("4", kResponder, kInitiator, transport_info_reply_b_xml));
+      EXPECT_EQ(0U, responder->sent_stanza_count());
+
+      // Deliver second reply transport-info message and expect ack.
+      initiator->DeliverStanza(responder->stanza());
+      initiator->ExpectSentStanza(
+          IqAck("4", kInitiator, kResponder));
+      EXPECT_EQ(0U, initiator->sent_stanza_count());
+    } else {
+      EXPECT_EQ(0U, initiator->sent_stanza_count());
+      EXPECT_EQ(0U, responder->sent_stanza_count());
+      responder->SkipUnsentStanza();
+    }
+
+    // The channels should be able to become writable at this point.  This
+    // requires pinging, so it may take a little while.
+    EXPECT_TRUE_WAIT(initiator->chan_a->writable() &&
+                     initiator->chan_a->readable(), kEventTimeout);
+    EXPECT_TRUE_WAIT(initiator->chan_b->writable() &&
+                     initiator->chan_b->readable(), kEventTimeout);
+    EXPECT_TRUE_WAIT(responder->chan_a->writable() &&
+                     responder->chan_a->readable(), kEventTimeout);
+    EXPECT_TRUE_WAIT(responder->chan_b->writable() &&
+                     responder->chan_b->readable(), kEventTimeout);
+
+    // Accept the session and expect accept stanza.
+    cricket::SessionDescription* answer = NewTestSessionDescription(
+        gingle_content_type,
+        content_name_a, content_type,
+        content_name_b, content_type);
+    if (bundle) {
+      cricket::ContentGroup group(cricket::GROUP_TYPE_BUNDLE);
+      group.AddContentName(content_name_a);
+      group.AddContentName(content_name_b);
+      EXPECT_TRUE(group.HasContentName(content_name_a));
+      EXPECT_TRUE(group.HasContentName(content_name_b));
+      answer->AddGroup(group);
+    }
+    EXPECT_TRUE(responder->session->Accept(answer));
+    EXPECT_EQ(responder->session->local_description(), answer);
+
+    responder->ExpectSentStanza(
+        IqSet("5", kResponder, kInitiator, accept_xml));
+
+    EXPECT_EQ(0U, responder->sent_stanza_count());
+
+    // Deliver the accept message and expect an ack.
+    initiator->DeliverStanza(responder->stanza());
+    EXPECT_TRUE_WAIT(initiator->sent_stanza_count() > 0, kEventTimeout);
+    initiator->ExpectSentStanza(
+        IqAck("5", kInitiator, kResponder));
+    EXPECT_EQ(0U, initiator->sent_stanza_count());
+
+    // Both sessions should be in progress and have functioning
+    // channels.
+    EXPECT_EQ(resulting_protocol, initiator->session->current_protocol());
+    EXPECT_EQ(resulting_protocol, responder->session->current_protocol());
+    EXPECT_EQ_WAIT(cricket::BaseSession::STATE_INPROGRESS,
+                   initiator->session_state(), kEventTimeout);
+    EXPECT_EQ_WAIT(cricket::BaseSession::STATE_INPROGRESS,
+                   responder->session_state(), kEventTimeout);
+    if (bundle) {
+      cricket::TransportChannel* initiator_chan_a = initiator->chan_a->channel;
+      cricket::TransportChannel* initiator_chan_b = initiator->chan_b->channel;
+
+      // Since we know these are TransportChannelProxy, type cast it.
+      cricket::TransportChannelProxy* initiator_proxy_chan_a =
+          static_cast<cricket::TransportChannelProxy*>(initiator_chan_a);
+      cricket::TransportChannelProxy* initiator_proxy_chan_b =
+              static_cast<cricket::TransportChannelProxy*>(initiator_chan_b);
+      EXPECT_TRUE(initiator_proxy_chan_a->impl() != NULL);
+      EXPECT_TRUE(initiator_proxy_chan_b->impl() != NULL);
+      EXPECT_EQ(initiator_proxy_chan_a->impl(), initiator_proxy_chan_b->impl());
+
+      cricket::TransportChannel* responder_chan_a = responder->chan_a->channel;
+      cricket::TransportChannel* responder_chan_b = responder->chan_b->channel;
+
+      // Since we know these are TransportChannelProxy, type cast it.
+      cricket::TransportChannelProxy* responder_proxy_chan_a =
+          static_cast<cricket::TransportChannelProxy*>(responder_chan_a);
+      cricket::TransportChannelProxy* responder_proxy_chan_b =
+              static_cast<cricket::TransportChannelProxy*>(responder_chan_b);
+      EXPECT_TRUE(responder_proxy_chan_a->impl() != NULL);
+      EXPECT_TRUE(responder_proxy_chan_b->impl() != NULL);
+      EXPECT_EQ(responder_proxy_chan_a->impl(), responder_proxy_chan_b->impl());
+    }
+    TestSendRecv(initiator->chan_a.get(), initiator->chan_b.get(),
+                 responder->chan_a.get(), responder->chan_b.get());
+
+    if (resulting_protocol == PROTOCOL_JINGLE) {
+      // Deliver a description-info message to the initiator and check if the
+      // content description changes.
+      EXPECT_EQ(0U, initiator->session_remote_description_update_count);
+
+      const cricket::SessionDescription* old_session_desc =
+          initiator->session->remote_description();
+      const cricket::ContentInfo* old_content_a =
+          old_session_desc->GetContentByName(content_name_a);
+      const cricket::ContentDescription* old_content_desc_a =
+          old_content_a->description;
+      const cricket::ContentInfo* old_content_b =
+          old_session_desc->GetContentByName(content_name_b);
+      const cricket::ContentDescription* old_content_desc_b =
+          old_content_b->description;
+      EXPECT_TRUE(old_content_desc_a != NULL);
+      EXPECT_TRUE(old_content_desc_b != NULL);
+
+      LOG(LS_INFO) << "A " << old_content_a->name;
+      LOG(LS_INFO) << "B " << old_content_b->name;
+
+      std::string description_info_xml =
+          JingleDescriptionInfoXml(content_name_a, content_type);
+      initiator->DeliverStanza(
+          IqSet("6", kResponder, kInitiator, description_info_xml));
+      responder->SkipUnsentStanza();
+      EXPECT_EQ(1U, initiator->session_remote_description_update_count);
+
+      const cricket::SessionDescription* new_session_desc =
+          initiator->session->remote_description();
+      const cricket::ContentInfo* new_content_a =
+          new_session_desc->GetContentByName(content_name_a);
+      const cricket::ContentDescription* new_content_desc_a =
+          new_content_a->description;
+      const cricket::ContentInfo* new_content_b =
+          new_session_desc->GetContentByName(content_name_b);
+      const cricket::ContentDescription* new_content_desc_b =
+          new_content_b->description;
+      EXPECT_TRUE(new_content_desc_a != NULL);
+      EXPECT_TRUE(new_content_desc_b != NULL);
+
+      // TODO: We used to replace contents from an update, but
+      // that no longer works with partial updates.  We need to figure out
+      // a way to merge patial updates into contents.  For now, users of
+      // Session should listen to SignalRemoteDescriptionUpdate and handle
+      // updates.  They should not expect remote_description to be the
+      // latest value.
+      // See session.cc OnDescriptionInfoMessage.
+
+      // EXPECT_NE(old_content_desc_a, new_content_desc_a);
+
+      // if (content_name_a != content_name_b) {
+      //   // If content_name_a != content_name_b, then b's content description
+      //   // should not have changed since the description-info message only
+      //   // contained an update for content_name_a.
+      //   EXPECT_EQ(old_content_desc_b, new_content_desc_b);
+      // }
+
+      EXPECT_TRUE_WAIT(initiator->sent_stanza_count() > 0, kEventTimeout);
+      initiator->ExpectSentStanza(
+          IqAck("6", kInitiator, kResponder));
+      EXPECT_EQ(0U, initiator->sent_stanza_count());
+    } else {
+      responder->SkipUnsentStanza();
+    }
+
+    initiator->session->Terminate();
+    initiator->ExpectSentStanza(
+        IqSet("7", kInitiator, kResponder,
+              TerminateXml(resulting_protocol,
+                           cricket::STR_TERMINATE_SUCCESS)));
+
+    responder->DeliverStanza(initiator->stanza());
+    responder->ExpectSentStanza(
+        IqAck("7", kResponder, kInitiator));
+    EXPECT_EQ(cricket::BaseSession::STATE_SENTTERMINATE,
+              initiator->session_state());
+    EXPECT_EQ(cricket::BaseSession::STATE_RECEIVEDTERMINATE,
+              responder->session_state());
+  }
+
+  // Test an initiate with other content, called "main".
+  void TestOtherContent(SignalingProtocol initiator_protocol,
+                        SignalingProtocol responder_protocol,
+                        SignalingProtocol resulting_protocol) {
+    std::string content_name = "main";
+    std::string content_type = "http://oink.splat/session";
+    std::string content_name_a = content_name;
+    std::string channel_name_a = "rtp";
+    std::string content_name_b = content_name;
+    std::string channel_name_b = "rtcp";
+    std::string initiate_xml = InitiateXml(
+        initiator_protocol,
+        content_name_a, content_type);
+    std::string transport_info_a_xml = TransportInfo4Xml(
+        initiator_protocol, content_name,
+        channel_name_a, 0, 1,
+        channel_name_b, 2, 3);
+    std::string transport_info_b_xml = "";
+    std::string transport_info_reply_a_xml = TransportInfo4Xml(
+        resulting_protocol, content_name,
+        channel_name_a, 4, 5,
+        channel_name_b, 6, 7);
+    std::string transport_info_reply_b_xml = "";
+    std::string accept_xml = AcceptXml(
+        resulting_protocol,
+        content_name_a, content_type);
+
+
+    TestSession(initiator_protocol, responder_protocol, resulting_protocol,
+                content_type,
+                content_type,
+                content_name_a, channel_name_a,
+                content_name_b, channel_name_b,
+                initiate_xml,
+                transport_info_a_xml, transport_info_b_xml,
+                transport_info_reply_a_xml, transport_info_reply_b_xml,
+                accept_xml);
+  }
+
+  // Test an initiate with audio content.
+  void TestAudioContent(SignalingProtocol initiator_protocol,
+                        SignalingProtocol responder_protocol,
+                        SignalingProtocol resulting_protocol) {
+    std::string gingle_content_type = cricket::NS_GINGLE_AUDIO;
+    std::string content_name = cricket::CN_AUDIO;
+    std::string content_type = cricket::NS_JINGLE_RTP;
+    std::string channel_name_a = "rtp";
+    std::string channel_name_b = "rtcp";
+    std::string initiate_xml = InitiateXml(
+        initiator_protocol,
+        gingle_content_type,
+        content_name, content_type,
+        "", "");
+    std::string transport_info_a_xml = TransportInfo4Xml(
+        initiator_protocol, content_name,
+        channel_name_a, 0, 1,
+        channel_name_b, 2, 3);
+    std::string transport_info_b_xml = "";
+    std::string transport_info_reply_a_xml = TransportInfo4Xml(
+        resulting_protocol, content_name,
+        channel_name_a, 4, 5,
+        channel_name_b, 6, 7);
+    std::string transport_info_reply_b_xml = "";
+    std::string accept_xml = AcceptXml(
+        resulting_protocol,
+        gingle_content_type,
+        content_name, content_type,
+        "", "");
+
+
+    TestSession(initiator_protocol, responder_protocol, resulting_protocol,
+                gingle_content_type,
+                content_type,
+                content_name, channel_name_a,
+                content_name, channel_name_b,
+                initiate_xml,
+                transport_info_a_xml, transport_info_b_xml,
+                transport_info_reply_a_xml, transport_info_reply_b_xml,
+                accept_xml);
+  }
+
+  // Since media content is "split" into two contents (audio and
+  // video), we need to treat it special.
+  void TestVideoContents(SignalingProtocol initiator_protocol,
+                         SignalingProtocol responder_protocol,
+                         SignalingProtocol resulting_protocol) {
+    std::string content_type = cricket::NS_JINGLE_RTP;
+    std::string gingle_content_type = cricket::NS_GINGLE_VIDEO;
+    std::string content_name_a = cricket::CN_AUDIO;
+    std::string channel_name_a = "rtp";
+    std::string content_name_b = cricket::CN_VIDEO;
+    std::string channel_name_b = "video_rtp";
+
+    std::string initiate_xml = InitiateXml(
+        initiator_protocol,
+        gingle_content_type,
+        content_name_a, content_type,
+        content_name_b, content_type);
+    std::string transport_info_a_xml = TransportInfo2Xml(
+        initiator_protocol, content_name_a,
+        channel_name_a, 0, 1);
+    std::string transport_info_b_xml = TransportInfo2Xml(
+        initiator_protocol, content_name_b,
+        channel_name_b, 2, 3);
+    std::string transport_info_reply_a_xml = TransportInfo2Xml(
+        resulting_protocol, content_name_a,
+        channel_name_a, 4, 5);
+    std::string transport_info_reply_b_xml = TransportInfo2Xml(
+        resulting_protocol, content_name_b,
+        channel_name_b, 6, 7);
+    std::string accept_xml = AcceptXml(
+        resulting_protocol,
+        gingle_content_type,
+        content_name_a, content_type,
+        content_name_b, content_type);
+
+    TestSession(initiator_protocol, responder_protocol, resulting_protocol,
+                gingle_content_type,
+                content_type,
+                content_name_a, channel_name_a,
+                content_name_b, channel_name_b,
+                initiate_xml,
+                transport_info_a_xml, transport_info_b_xml,
+                transport_info_reply_a_xml, transport_info_reply_b_xml,
+                accept_xml);
+  }
+
+  void TestBadRedirect(SignalingProtocol protocol) {
+    std::string content_name = "main";
+    std::string content_type = "http://oink.splat/session";
+    std::string channel_name_a = "chana";
+    std::string channel_name_b = "chanb";
+    std::string initiate_xml = InitiateXml(
+        protocol, content_name, content_type);
+    std::string transport_info_xml = TransportInfo4Xml(
+        protocol, content_name,
+        channel_name_a, 0, 1,
+        channel_name_b, 2, 3);
+    std::string transport_info_reply_xml = TransportInfo4Xml(
+        protocol, content_name,
+        channel_name_a, 4, 5,
+        channel_name_b, 6, 7);
+    std::string accept_xml = AcceptXml(
+        protocol, content_name, content_type);
+    std::string responder_full = kResponder + "/full";
+
+    rtc::scoped_ptr<cricket::PortAllocator> allocator(
+        new TestPortAllocator());
+    int next_message_id = 0;
+
+    rtc::scoped_ptr<TestClient> initiator(
+        new TestClient(allocator.get(), &next_message_id,
+                       kInitiator, protocol,
+                       content_type,
+                       content_name, channel_name_a,
+                       content_name, channel_name_b));
+
+    rtc::scoped_ptr<TestClient> responder(
+        new TestClient(allocator.get(), &next_message_id,
+                       responder_full, protocol,
+                       content_type,
+                       content_name,  channel_name_a,
+                       content_name,  channel_name_b));
+
+    // Create Session and check channels and state.
+    initiator->CreateSession();
+    EXPECT_EQ(1U, initiator->session_created_count);
+    EXPECT_EQ(kSessionId, initiator->session->id());
+    EXPECT_EQ(initiator->session->local_name(), kInitiator);
+    EXPECT_EQ(cricket::BaseSession::STATE_INIT,
+              initiator->session_state());
+
+    EXPECT_TRUE(initiator->HasChannel(content_name, 1));
+    EXPECT_TRUE(initiator->HasChannel(content_name, 2));
+
+    // Initiate and expect initiate message sent.
+    cricket::SessionDescription* offer = NewTestSessionDescription(
+        content_name, content_type);
+    EXPECT_TRUE(initiator->session->Initiate(kResponder, offer));
+    EXPECT_EQ(initiator->session->remote_name(), kResponder);
+    EXPECT_EQ(initiator->session->local_description(), offer);
+
+    EXPECT_TRUE_WAIT(initiator->sent_stanza_count() > 0, kEventTimeout);
+    EXPECT_EQ(cricket::BaseSession::STATE_SENTINITIATE,
+              initiator->session_state());
+    initiator->ExpectSentStanza(
+        IqSet("0", kInitiator, kResponder, initiate_xml));
+
+    // Expect transport-info message from initiator.
+    initiator->DeliverAckToLastStanza();
+    initiator->PrepareCandidates();
+    EXPECT_TRUE_WAIT(initiator->sent_stanza_count() > 0, kEventTimeout);
+    initiator->ExpectSentStanza(
+        IqSet("1", kInitiator, kResponder, transport_info_xml));
+
+    // Send an unauthorized redirect to the initiator and expect it be ignored.
+    initiator->blow_up_on_error = false;
+    const buzz::XmlElement* initiate_stanza = initiator->stanza();
+    rtc::scoped_ptr<buzz::XmlElement> redirect_stanza(
+        buzz::XmlElement::ForStr(
+            IqError("ER", kResponder, kInitiator,
+                    RedirectXml(protocol, initiate_xml, "not@allowed.com"))));
+    initiator->session_manager->OnFailedSend(
+        initiate_stanza, redirect_stanza.get());
+    EXPECT_EQ(initiator->session->remote_name(), kResponder);
+    initiator->blow_up_on_error = true;
+    EXPECT_EQ(initiator->error_count, 1);
+  }
+
+  void TestGoodRedirect(SignalingProtocol protocol) {
+    std::string content_name = "main";
+    std::string content_type = "http://oink.splat/session";
+    std::string channel_name_a = "chana";
+    std::string channel_name_b = "chanb";
+    std::string initiate_xml = InitiateXml(
+        protocol, content_name, content_type);
+    std::string transport_info_xml = TransportInfo4Xml(
+        protocol, content_name,
+        channel_name_a, 0, 1,
+        channel_name_b, 2, 3);
+    std::string transport_info_reply_xml = TransportInfo4Xml(
+        protocol, content_name,
+        channel_name_a, 4, 5,
+        channel_name_b, 6, 7);
+    std::string accept_xml = AcceptXml(
+        protocol, content_name, content_type);
+    std::string responder_full = kResponder + "/full";
+
+    rtc::scoped_ptr<cricket::PortAllocator> allocator(
+        new TestPortAllocator());
+    int next_message_id = 0;
+
+    rtc::scoped_ptr<TestClient> initiator(
+        new TestClient(allocator.get(), &next_message_id,
+                       kInitiator, protocol,
+                       content_type,
+                       content_name, channel_name_a,
+                       content_name, channel_name_b));
+
+    rtc::scoped_ptr<TestClient> responder(
+        new TestClient(allocator.get(), &next_message_id,
+                       responder_full, protocol,
+                       content_type,
+                       content_name,  channel_name_a,
+                       content_name,  channel_name_b));
+
+    // Create Session and check channels and state.
+    initiator->CreateSession();
+    EXPECT_EQ(1U, initiator->session_created_count);
+    EXPECT_EQ(kSessionId, initiator->session->id());
+    EXPECT_EQ(initiator->session->local_name(), kInitiator);
+    EXPECT_EQ(cricket::BaseSession::STATE_INIT,
+              initiator->session_state());
+
+    EXPECT_TRUE(initiator->HasChannel(content_name, 1));
+    EXPECT_TRUE(initiator->HasChannel(content_name, 2));
+
+    // Initiate and expect initiate message sent.
+    cricket::SessionDescription* offer = NewTestSessionDescription(
+        content_name, content_type);
+    EXPECT_TRUE(initiator->session->Initiate(kResponder, offer));
+    EXPECT_EQ(initiator->session->remote_name(), kResponder);
+    EXPECT_EQ(initiator->session->local_description(), offer);
+
+    EXPECT_TRUE_WAIT(initiator->sent_stanza_count() > 0, kEventTimeout);
+    EXPECT_EQ(cricket::BaseSession::STATE_SENTINITIATE,
+              initiator->session_state());
+    initiator->ExpectSentStanza(
+        IqSet("0", kInitiator, kResponder, initiate_xml));
+
+    // Expect transport-info message from initiator.
+    initiator->DeliverAckToLastStanza();
+    initiator->PrepareCandidates();
+    EXPECT_TRUE_WAIT(initiator->sent_stanza_count() > 0, kEventTimeout);
+    initiator->ExpectSentStanza(
+        IqSet("1", kInitiator, kResponder, transport_info_xml));
+
+    // Send a redirect to the initiator and expect all of the message
+    // to be resent.
+    const buzz::XmlElement* initiate_stanza = initiator->stanza();
+    rtc::scoped_ptr<buzz::XmlElement> redirect_stanza(
+        buzz::XmlElement::ForStr(
+            IqError("ER2", kResponder, kInitiator,
+                    RedirectXml(protocol, initiate_xml, responder_full))));
+    initiator->session_manager->OnFailedSend(
+        initiate_stanza, redirect_stanza.get());
+    EXPECT_EQ(initiator->session->remote_name(), responder_full);
+
+    EXPECT_TRUE_WAIT(initiator->sent_stanza_count() > 0, kEventTimeout);
+    initiator->ExpectSentStanza(
+        IqSet("2", kInitiator, responder_full, initiate_xml));
+    initiator->ExpectSentStanza(
+        IqSet("3", kInitiator, responder_full, transport_info_xml));
+
+    // Deliver the initiate. Expect ack and session created with
+    // transports.
+    responder->DeliverStanza(
+        IqSet("2", kInitiator, responder_full, initiate_xml));
+    responder->ExpectSentStanza(
+        IqAck("2", responder_full, kInitiator));
+    EXPECT_EQ(0U, responder->sent_stanza_count());
+
+    EXPECT_EQ(1U, responder->session_created_count);
+    EXPECT_EQ(kSessionId, responder->session->id());
+    EXPECT_EQ(responder->session->local_name(), responder_full);
+    EXPECT_EQ(responder->session->remote_name(), kInitiator);
+    EXPECT_EQ(cricket::BaseSession::STATE_RECEIVEDINITIATE,
+              responder->session_state());
+
+    EXPECT_TRUE(responder->HasChannel(content_name, 1));
+    EXPECT_TRUE(responder->HasChannel(content_name, 2));
+
+    // Deliver transport-info and expect ack.
+    responder->DeliverStanza(
+        IqSet("3", kInitiator, responder_full, transport_info_xml));
+    responder->ExpectSentStanza(
+        IqAck("3", responder_full, kInitiator));
+
+    // Expect reply transport-infos sent to new remote JID
+    responder->PrepareCandidates();
+    EXPECT_TRUE_WAIT(responder->sent_stanza_count() > 0, kEventTimeout);
+    responder->ExpectSentStanza(
+        IqSet("4", responder_full, kInitiator, transport_info_reply_xml));
+
+    initiator->DeliverStanza(responder->stanza());
+    initiator->ExpectSentStanza(
+        IqAck("4", kInitiator, responder_full));
+
+    // The channels should be able to become writable at this point.  This
+    // requires pinging, so it may take a little while.
+    EXPECT_TRUE_WAIT(initiator->chan_a->writable() &&
+                     initiator->chan_a->readable(), kEventTimeout);
+    EXPECT_TRUE_WAIT(initiator->chan_b->writable() &&
+                     initiator->chan_b->readable(), kEventTimeout);
+    EXPECT_TRUE_WAIT(responder->chan_a->writable() &&
+                     responder->chan_a->readable(), kEventTimeout);
+    EXPECT_TRUE_WAIT(responder->chan_b->writable() &&
+                     responder->chan_b->readable(), kEventTimeout);
+
+    // Accept the session and expect accept stanza.
+    cricket::SessionDescription* answer = NewTestSessionDescription(
+        content_name, content_type);
+    EXPECT_TRUE(responder->session->Accept(answer));
+    EXPECT_EQ(responder->session->local_description(), answer);
+
+    responder->ExpectSentStanza(
+        IqSet("5", responder_full, kInitiator, accept_xml));
+    EXPECT_EQ(0U, responder->sent_stanza_count());
+
+    // Deliver the accept message and expect an ack.
+    initiator->DeliverStanza(responder->stanza());
+    EXPECT_TRUE_WAIT(initiator->sent_stanza_count() > 0, kEventTimeout);
+    initiator->ExpectSentStanza(
+        IqAck("5", kInitiator, responder_full));
+    EXPECT_EQ(0U, initiator->sent_stanza_count());
+
+    // Both sessions should be in progress and have functioning
+    // channels.
+    EXPECT_EQ_WAIT(cricket::BaseSession::STATE_INPROGRESS,
+                   initiator->session_state(), kEventTimeout);
+    EXPECT_EQ_WAIT(cricket::BaseSession::STATE_INPROGRESS,
+                   responder->session_state(), kEventTimeout);
+    TestSendRecv(initiator->chan_a.get(), initiator->chan_b.get(),
+                 responder->chan_a.get(), responder->chan_b.get());
+  }
+
+  void TestCandidatesInInitiateAndAccept(const std::string& test_name) {
+    std::string content_name = "main";
+    std::string content_type = "http://oink.splat/session";
+    std::string channel_name_a = "rtp";
+    std::string channel_name_b = "rtcp";
+    cricket::SignalingProtocol protocol = PROTOCOL_JINGLE;
+
+    rtc::scoped_ptr<cricket::PortAllocator> allocator(
+        new TestPortAllocator());
+    int next_message_id = 0;
+
+    rtc::scoped_ptr<TestClient> initiator(
+        new TestClient(allocator.get(), &next_message_id,
+                       kInitiator, protocol,
+                       content_type,
+                       content_name,  channel_name_a,
+                       content_name,  channel_name_b));
+
+    rtc::scoped_ptr<TestClient> responder(
+        new TestClient(allocator.get(), &next_message_id,
+                       kResponder, protocol,
+                       content_type,
+                       content_name,  channel_name_a,
+                       content_name,  channel_name_b));
+
+    // Create Session and check channels and state.
+    initiator->CreateSession();
+    EXPECT_TRUE(initiator->HasTransport(content_name));
+    EXPECT_TRUE(initiator->HasChannel(content_name, 1));
+    EXPECT_TRUE(initiator->HasTransport(content_name));
+    EXPECT_TRUE(initiator->HasChannel(content_name, 2));
+
+    // Initiate and expect initiate message sent.
+    cricket::SessionDescription* offer = NewTestSessionDescription(
+        content_name, content_type);
+    EXPECT_TRUE(initiator->session->Initiate(kResponder, offer));
+
+    EXPECT_TRUE_WAIT(initiator->sent_stanza_count() > 0, kEventTimeout);
+    EXPECT_EQ(cricket::BaseSession::STATE_SENTINITIATE,
+              initiator->session_state());
+    initiator->ExpectSentStanza(
+        IqSet("0", kInitiator, kResponder,
+              InitiateXml(protocol, content_name, content_type)));
+
+    // Fake the delivery the initiate and candidates together.
+    responder->DeliverStanza(
+        IqSet("A", kInitiator, kResponder,
+            JingleInitiateActionXml(
+                JingleContentXml(
+                    content_name, content_type, kTransportType,
+                    P2pCandidateXml(channel_name_a, 0) +
+                    P2pCandidateXml(channel_name_a, 1) +
+                    P2pCandidateXml(channel_name_b, 2) +
+                    P2pCandidateXml(channel_name_b, 3)))));
+    responder->ExpectSentStanza(
+        IqAck("A", kResponder, kInitiator));
+    EXPECT_EQ(0U, responder->sent_stanza_count());
+
+    EXPECT_EQ(1U, responder->session_created_count);
+    EXPECT_EQ(kSessionId, responder->session->id());
+    EXPECT_EQ(responder->session->local_name(), kResponder);
+    EXPECT_EQ(responder->session->remote_name(), kInitiator);
+    EXPECT_EQ(cricket::BaseSession::STATE_RECEIVEDINITIATE,
+              responder->session_state());
+
+    EXPECT_TRUE(responder->HasTransport(content_name));
+    EXPECT_TRUE(responder->HasChannel(content_name, 1));
+    EXPECT_TRUE(responder->HasTransport(content_name));
+    EXPECT_TRUE(responder->HasChannel(content_name, 2));
+
+    // Expect transport-info message from initiator.
+    // But don't send candidates until initiate ack is received.
+    initiator->DeliverAckToLastStanza();
+    initiator->PrepareCandidates();
+    EXPECT_TRUE_WAIT(initiator->sent_stanza_count() > 0, kEventTimeout);
+    initiator->ExpectSentStanza(
+        IqSet("1", kInitiator, kResponder,
+              TransportInfo4Xml(protocol, content_name,
+                                channel_name_a, 0, 1,
+                                channel_name_b, 2, 3)));
+
+    responder->PrepareCandidates();
+    EXPECT_TRUE_WAIT(responder->sent_stanza_count() > 0, kEventTimeout);
+    responder->ExpectSentStanza(
+        IqSet("2", kResponder, kInitiator,
+              TransportInfo4Xml(protocol, content_name,
+                                channel_name_a, 4, 5,
+                                channel_name_b, 6, 7)));
+
+    // Accept the session and expect accept stanza.
+    cricket::SessionDescription* answer = NewTestSessionDescription(
+        content_name, content_type);
+    EXPECT_TRUE(responder->session->Accept(answer));
+
+    responder->ExpectSentStanza(
+        IqSet("3", kResponder, kInitiator,
+              AcceptXml(protocol, content_name, content_type)));
+    EXPECT_EQ(0U, responder->sent_stanza_count());
+
+    // Fake the delivery the accept and candidates together.
+    initiator->DeliverStanza(
+        IqSet("B", kResponder, kInitiator,
+            JingleActionXml("session-accept",
+                JingleContentXml(
+                    content_name, content_type, kTransportType,
+                    P2pCandidateXml(channel_name_a, 4) +
+                    P2pCandidateXml(channel_name_a, 5) +
+                    P2pCandidateXml(channel_name_b, 6) +
+                    P2pCandidateXml(channel_name_b, 7)))));
+    EXPECT_TRUE_WAIT(initiator->sent_stanza_count() > 0, kEventTimeout);
+    initiator->ExpectSentStanza(
+        IqAck("B", kInitiator, kResponder));
+    EXPECT_EQ(0U, initiator->sent_stanza_count());
+
+    // The channels should be able to become writable at this point.  This
+    // requires pinging, so it may take a little while.
+    EXPECT_TRUE_WAIT(initiator->chan_a->writable() &&
+                     initiator->chan_a->readable(), kEventTimeout);
+    EXPECT_TRUE_WAIT(initiator->chan_b->writable() &&
+                     initiator->chan_b->readable(), kEventTimeout);
+    EXPECT_TRUE_WAIT(responder->chan_a->writable() &&
+                     responder->chan_a->readable(), kEventTimeout);
+    EXPECT_TRUE_WAIT(responder->chan_b->writable() &&
+                     responder->chan_b->readable(), kEventTimeout);
+
+
+    // Both sessions should be in progress and have functioning
+    // channels.
+    EXPECT_EQ(protocol, initiator->session->current_protocol());
+    EXPECT_EQ(protocol, responder->session->current_protocol());
+    EXPECT_EQ_WAIT(cricket::BaseSession::STATE_INPROGRESS,
+                   initiator->session_state(), kEventTimeout);
+    EXPECT_EQ_WAIT(cricket::BaseSession::STATE_INPROGRESS,
+                   responder->session_state(), kEventTimeout);
+    TestSendRecv(initiator->chan_a.get(), initiator->chan_b.get(),
+                 responder->chan_a.get(), responder->chan_b.get());
+  }
+
+  // Tests that when an initiator terminates right after initiate,
+  // everything behaves correctly.
+  void TestEarlyTerminationFromInitiator(SignalingProtocol protocol) {
+    std::string content_name = "main";
+    std::string content_type = "http://oink.splat/session";
+
+    rtc::scoped_ptr<cricket::PortAllocator> allocator(
+        new TestPortAllocator());
+    int next_message_id = 0;
+
+    rtc::scoped_ptr<TestClient> initiator(
+        new TestClient(allocator.get(), &next_message_id,
+                       kInitiator, protocol,
+                       content_type,
+                       content_name, "a",
+                       content_name, "b"));
+
+    rtc::scoped_ptr<TestClient> responder(
+        new TestClient(allocator.get(), &next_message_id,
+                       kResponder, protocol,
+                       content_type,
+                       content_name,  "a",
+                       content_name,  "b"));
+
+    // Send initiate
+    initiator->CreateSession();
+    EXPECT_TRUE(initiator->session->Initiate(
+        kResponder, NewTestSessionDescription(content_name, content_type)));
+    initiator->ExpectSentStanza(
+        IqSet("0", kInitiator, kResponder,
+              InitiateXml(protocol, content_name, content_type)));
+    EXPECT_EQ(cricket::BaseSession::STATE_SENTINITIATE,
+              initiator->session_state());
+
+    responder->DeliverStanza(initiator->stanza());
+    responder->ExpectSentStanza(
+        IqAck("0", kResponder, kInitiator));
+    EXPECT_EQ(cricket::BaseSession::STATE_RECEIVEDINITIATE,
+              responder->session_state());
+
+    initiator->session->TerminateWithReason(cricket::STR_TERMINATE_ERROR);
+    initiator->ExpectSentStanza(
+        IqSet("1", kInitiator, kResponder,
+              TerminateXml(protocol, cricket::STR_TERMINATE_ERROR)));
+    EXPECT_EQ(cricket::BaseSession::STATE_SENTTERMINATE,
+              initiator->session_state());
+
+    responder->DeliverStanza(initiator->stanza());
+    responder->ExpectSentStanza(
+        IqAck("1", kResponder, kInitiator));
+    EXPECT_EQ(cricket::BaseSession::STATE_RECEIVEDTERMINATE,
+              responder->session_state());
+  }
+
+  // Tests that when the responder rejects, everything behaves
+  // correctly.
+  void TestRejection(SignalingProtocol protocol) {
+    std::string content_name = "main";
+    std::string content_type = "http://oink.splat/session";
+
+    rtc::scoped_ptr<cricket::PortAllocator> allocator(
+        new TestPortAllocator());
+    int next_message_id = 0;
+
+    rtc::scoped_ptr<TestClient> initiator(
+        new TestClient(allocator.get(), &next_message_id,
+                       kInitiator, protocol,
+                       content_type,
+                       content_name, "a",
+                       content_name, "b"));
+
+    // Send initiate
+    initiator->CreateSession();
+    EXPECT_TRUE(initiator->session->Initiate(
+        kResponder, NewTestSessionDescription(content_name, content_type)));
+    initiator->ExpectSentStanza(
+        IqSet("0", kInitiator, kResponder,
+              InitiateXml(protocol, content_name, content_type)));
+    EXPECT_EQ(cricket::BaseSession::STATE_SENTINITIATE,
+              initiator->session_state());
+
+    initiator->DeliverStanza(
+        IqSet("1", kResponder, kInitiator,
+              RejectXml(protocol, cricket::STR_TERMINATE_ERROR)));
+    initiator->ExpectSentStanza(
+        IqAck("1", kInitiator, kResponder));
+    if (protocol == PROTOCOL_JINGLE) {
+      EXPECT_EQ(cricket::BaseSession::STATE_RECEIVEDTERMINATE,
+                initiator->session_state());
+    } else {
+      EXPECT_EQ(cricket::BaseSession::STATE_RECEIVEDREJECT,
+                initiator->session_state());
+    }
+  }
+
+  void TestTransportMux() {
+    SignalingProtocol initiator_protocol = PROTOCOL_JINGLE;
+    SignalingProtocol responder_protocol = PROTOCOL_JINGLE;
+    SignalingProtocol resulting_protocol = PROTOCOL_JINGLE;
+    std::string content_type = cricket::NS_JINGLE_RTP;
+    std::string gingle_content_type = cricket::NS_GINGLE_VIDEO;
+    std::string content_name_a = cricket::CN_AUDIO;
+    std::string channel_name_a = "rtp";
+    std::string content_name_b = cricket::CN_VIDEO;
+    std::string channel_name_b = "video_rtp";
+
+    std::string initiate_xml = InitiateXml(
+        initiator_protocol,
+        gingle_content_type,
+        content_name_a, content_type,
+        content_name_b, content_type, true);
+    std::string transport_info_a_xml = TransportInfo2Xml(
+        initiator_protocol, content_name_a,
+        channel_name_a, 0, 1);
+    std::string transport_info_b_xml = TransportInfo2Xml(
+        initiator_protocol, content_name_b,
+        channel_name_b, 2, 3);
+    std::string transport_info_reply_a_xml = TransportInfo2Xml(
+        resulting_protocol, content_name_a,
+        channel_name_a, 4, 5);
+    std::string transport_info_reply_b_xml = TransportInfo2Xml(
+        resulting_protocol, content_name_b,
+        channel_name_b, 6, 7);
+    std::string accept_xml = AcceptXml(
+        resulting_protocol,
+        gingle_content_type,
+        content_name_a, content_type,
+        content_name_b, content_type, true);
+
+    TestSession(initiator_protocol, responder_protocol, resulting_protocol,
+                gingle_content_type,
+                content_type,
+                content_name_a, channel_name_a,
+                content_name_b, channel_name_b,
+                initiate_xml,
+                transport_info_a_xml, transport_info_b_xml,
+                transport_info_reply_a_xml, transport_info_reply_b_xml,
+                accept_xml,
+                true);
+  }
+
+  void TestSendDescriptionInfo() {
+    rtc::scoped_ptr<cricket::PortAllocator> allocator(
+        new TestPortAllocator());
+    int next_message_id = 0;
+
+    std::string content_name = "content-name";
+    std::string content_type = "content-type";
+    rtc::scoped_ptr<TestClient> initiator(
+        new TestClient(allocator.get(), &next_message_id,
+                       kInitiator, PROTOCOL_JINGLE,
+                       content_type,
+                       content_name, "",
+                       "",  ""));
+
+    initiator->CreateSession();
+    cricket::SessionDescription* offer = NewTestSessionDescription(
+        content_name, content_type);
+    std::string initiate_xml = InitiateXml(
+        PROTOCOL_JINGLE, content_name, content_type);
+
+    cricket::ContentInfos contents;
+    TestContentDescription content(content_type, content_type);
+    contents.push_back(
+        cricket::ContentInfo(content_name, content_type, &content));
+    std::string description_info_xml = JingleDescriptionInfoXml(
+        content_name, content_type);
+
+    EXPECT_TRUE(initiator->session->Initiate(kResponder, offer));
+    initiator->ExpectSentStanza(
+        IqSet("0", kInitiator, kResponder, initiate_xml));
+
+    EXPECT_TRUE(initiator->session->SendDescriptionInfoMessage(contents));
+    initiator->ExpectSentStanza(
+        IqSet("1", kInitiator, kResponder, description_info_xml));
+  }
+
+  void DoTestSignalNewDescription(
+      TestClient* client,
+      cricket::BaseSession::State state,
+      cricket::ContentAction expected_content_action,
+      cricket::ContentSource expected_content_source) {
+    // Clean up before the new test.
+    client->new_local_description = false;
+    client->new_remote_description = false;
+
+    client->SetSessionState(state);
+    EXPECT_EQ((expected_content_source == cricket::CS_LOCAL),
+               client->new_local_description);
+    EXPECT_EQ((expected_content_source == cricket::CS_REMOTE),
+               client->new_remote_description);
+    EXPECT_EQ(expected_content_action, client->last_content_action);
+    EXPECT_EQ(expected_content_source, client->last_content_source);
+  }
+
+  void TestCallerSignalNewDescription() {
+    rtc::scoped_ptr<cricket::PortAllocator> allocator(
+        new TestPortAllocator());
+    int next_message_id = 0;
+
+    std::string content_name = "content-name";
+    std::string content_type = "content-type";
+    rtc::scoped_ptr<TestClient> initiator(
+        new TestClient(allocator.get(), &next_message_id,
+                       kInitiator, PROTOCOL_JINGLE,
+                       content_type,
+                       content_name, "",
+                       "",  ""));
+
+    initiator->CreateSession();
+
+    // send offer -> send update offer ->
+    // receive pr answer -> receive update pr answer ->
+    // receive answer
+    DoTestSignalNewDescription(
+        initiator.get(), cricket::BaseSession::STATE_SENTINITIATE,
+        cricket::CA_OFFER, cricket::CS_LOCAL);
+
+    DoTestSignalNewDescription(
+        initiator.get(), cricket::BaseSession::STATE_SENTINITIATE,
+        cricket::CA_OFFER, cricket::CS_LOCAL);
+
+    DoTestSignalNewDescription(
+        initiator.get(), cricket::BaseSession::STATE_RECEIVEDPRACCEPT,
+        cricket::CA_PRANSWER, cricket::CS_REMOTE);
+
+    DoTestSignalNewDescription(
+        initiator.get(), cricket::BaseSession::STATE_RECEIVEDPRACCEPT,
+        cricket::CA_PRANSWER, cricket::CS_REMOTE);
+
+    DoTestSignalNewDescription(
+        initiator.get(), cricket::BaseSession::STATE_RECEIVEDACCEPT,
+        cricket::CA_ANSWER, cricket::CS_REMOTE);
+  }
+
+  void TestCalleeSignalNewDescription() {
+    rtc::scoped_ptr<cricket::PortAllocator> allocator(
+        new TestPortAllocator());
+    int next_message_id = 0;
+
+    std::string content_name = "content-name";
+    std::string content_type = "content-type";
+    rtc::scoped_ptr<TestClient> initiator(
+        new TestClient(allocator.get(), &next_message_id,
+                       kInitiator, PROTOCOL_JINGLE,
+                       content_type,
+                       content_name, "",
+                       "",  ""));
+
+    initiator->CreateSession();
+
+    // receive offer -> receive update offer ->
+    // send pr answer -> send update pr answer ->
+    // send answer
+    DoTestSignalNewDescription(
+        initiator.get(), cricket::BaseSession::STATE_RECEIVEDINITIATE,
+        cricket::CA_OFFER, cricket::CS_REMOTE);
+
+    DoTestSignalNewDescription(
+        initiator.get(), cricket::BaseSession::STATE_RECEIVEDINITIATE,
+        cricket::CA_OFFER, cricket::CS_REMOTE);
+
+    DoTestSignalNewDescription(
+        initiator.get(), cricket::BaseSession::STATE_SENTPRACCEPT,
+        cricket::CA_PRANSWER, cricket::CS_LOCAL);
+
+    DoTestSignalNewDescription(
+        initiator.get(), cricket::BaseSession::STATE_SENTPRACCEPT,
+        cricket::CA_PRANSWER, cricket::CS_LOCAL);
+
+    DoTestSignalNewDescription(
+        initiator.get(), cricket::BaseSession::STATE_SENTACCEPT,
+        cricket::CA_ANSWER, cricket::CS_LOCAL);
+  }
+
+  void TestGetTransportStats() {
+    rtc::scoped_ptr<cricket::PortAllocator> allocator(
+        new TestPortAllocator());
+    int next_message_id = 0;
+
+    std::string content_name = "content-name";
+    std::string content_type = "content-type";
+    rtc::scoped_ptr<TestClient> initiator(
+        new TestClient(allocator.get(), &next_message_id,
+                       kInitiator, PROTOCOL_JINGLE,
+                       content_type,
+                       content_name, "",
+                       "",  ""));
+    initiator->CreateSession();
+
+    cricket::SessionStats stats;
+    EXPECT_TRUE(initiator->session->GetStats(&stats));
+    // At initiation, there are 2 transports.
+    EXPECT_EQ(2ul, stats.proxy_to_transport.size());
+    EXPECT_EQ(2ul, stats.transport_stats.size());
+  }
+};
+
+// For each of these, "X => Y = Z" means "if a client with protocol X
+// initiates to a client with protocol Y, they end up speaking protocol Z.
+
+// Gingle => Gingle = Gingle (with other content)
+TEST_F(SessionTest, GingleToGingleOtherContent) {
+  TestOtherContent(PROTOCOL_GINGLE, PROTOCOL_GINGLE, PROTOCOL_GINGLE);
+}
+
+// Gingle => Gingle = Gingle (with audio content)
+TEST_F(SessionTest, GingleToGingleAudioContent) {
+  TestAudioContent(PROTOCOL_GINGLE, PROTOCOL_GINGLE, PROTOCOL_GINGLE);
+}
+
+// Gingle => Gingle = Gingle (with video contents)
+TEST_F(SessionTest, GingleToGingleVideoContents) {
+  TestVideoContents(PROTOCOL_GINGLE, PROTOCOL_GINGLE, PROTOCOL_GINGLE);
+}
+
+// Jingle => Jingle = Jingle (with other content)
+TEST_F(SessionTest, JingleToJingleOtherContent) {
+  TestOtherContent(PROTOCOL_JINGLE, PROTOCOL_JINGLE, PROTOCOL_JINGLE);
+}
+
+// Jingle => Jingle = Jingle (with audio content)
+TEST_F(SessionTest, JingleToJingleAudioContent) {
+  TestAudioContent(PROTOCOL_JINGLE, PROTOCOL_JINGLE, PROTOCOL_JINGLE);
+}
+
+// Jingle => Jingle = Jingle (with video contents)
+TEST_F(SessionTest, JingleToJingleVideoContents) {
+  TestVideoContents(PROTOCOL_JINGLE, PROTOCOL_JINGLE, PROTOCOL_JINGLE);
+}
+
+// Hybrid => Hybrid = Jingle (with other content)
+TEST_F(SessionTest, HybridToHybridOtherContent) {
+  TestOtherContent(PROTOCOL_HYBRID, PROTOCOL_HYBRID, PROTOCOL_JINGLE);
+}
+
+// Hybrid => Hybrid = Jingle (with audio content)
+TEST_F(SessionTest, HybridToHybridAudioContent) {
+  TestAudioContent(PROTOCOL_HYBRID, PROTOCOL_HYBRID, PROTOCOL_JINGLE);
+}
+
+// Hybrid => Hybrid = Jingle (with video contents)
+TEST_F(SessionTest, HybridToHybridVideoContents) {
+  TestVideoContents(PROTOCOL_HYBRID, PROTOCOL_HYBRID, PROTOCOL_JINGLE);
+}
+
+// Gingle => Hybrid = Gingle (with other content)
+TEST_F(SessionTest, GingleToHybridOtherContent) {
+  TestOtherContent(PROTOCOL_GINGLE, PROTOCOL_HYBRID, PROTOCOL_GINGLE);
+}
+
+// Gingle => Hybrid = Gingle (with audio content)
+TEST_F(SessionTest, GingleToHybridAudioContent) {
+  TestAudioContent(PROTOCOL_GINGLE, PROTOCOL_HYBRID, PROTOCOL_GINGLE);
+}
+
+// Gingle => Hybrid = Gingle (with video contents)
+TEST_F(SessionTest, GingleToHybridVideoContents) {
+  TestVideoContents(PROTOCOL_GINGLE, PROTOCOL_HYBRID, PROTOCOL_GINGLE);
+}
+
+// Jingle => Hybrid = Jingle (with other content)
+TEST_F(SessionTest, JingleToHybridOtherContent) {
+  TestOtherContent(PROTOCOL_JINGLE, PROTOCOL_HYBRID, PROTOCOL_JINGLE);
+}
+
+// Jingle => Hybrid = Jingle (with audio content)
+TEST_F(SessionTest, JingleToHybridAudioContent) {
+  TestAudioContent(PROTOCOL_JINGLE, PROTOCOL_HYBRID, PROTOCOL_JINGLE);
+}
+
+// Jingle => Hybrid = Jingle (with video contents)
+TEST_F(SessionTest, JingleToHybridVideoContents) {
+  TestVideoContents(PROTOCOL_JINGLE, PROTOCOL_HYBRID, PROTOCOL_JINGLE);
+}
+
+// Hybrid => Gingle = Gingle (with other content)
+TEST_F(SessionTest, HybridToGingleOtherContent) {
+  TestOtherContent(PROTOCOL_HYBRID, PROTOCOL_GINGLE, PROTOCOL_GINGLE);
+}
+
+// Hybrid => Gingle = Gingle (with audio content)
+TEST_F(SessionTest, HybridToGingleAudioContent) {
+  TestAudioContent(PROTOCOL_HYBRID, PROTOCOL_GINGLE, PROTOCOL_GINGLE);
+}
+
+// Hybrid => Gingle = Gingle (with video contents)
+TEST_F(SessionTest, HybridToGingleVideoContents) {
+  TestVideoContents(PROTOCOL_HYBRID, PROTOCOL_GINGLE, PROTOCOL_GINGLE);
+}
+
+// Hybrid => Jingle = Jingle (with other content)
+TEST_F(SessionTest, HybridToJingleOtherContent) {
+  TestOtherContent(PROTOCOL_HYBRID, PROTOCOL_JINGLE, PROTOCOL_JINGLE);
+}
+
+// Hybrid => Jingle = Jingle (with audio content)
+TEST_F(SessionTest, HybridToJingleAudioContent) {
+  TestAudioContent(PROTOCOL_HYBRID, PROTOCOL_JINGLE, PROTOCOL_JINGLE);
+}
+
+// Hybrid => Jingle = Jingle (with video contents)
+TEST_F(SessionTest, HybridToJingleVideoContents) {
+  TestVideoContents(PROTOCOL_HYBRID, PROTOCOL_JINGLE, PROTOCOL_JINGLE);
+}
+
+TEST_F(SessionTest, GingleEarlyTerminationFromInitiator) {
+  TestEarlyTerminationFromInitiator(PROTOCOL_GINGLE);
+}
+
+TEST_F(SessionTest, JingleEarlyTerminationFromInitiator) {
+  TestEarlyTerminationFromInitiator(PROTOCOL_JINGLE);
+}
+
+TEST_F(SessionTest, HybridEarlyTerminationFromInitiator) {
+  TestEarlyTerminationFromInitiator(PROTOCOL_HYBRID);
+}
+
+TEST_F(SessionTest, GingleRejection) {
+  TestRejection(PROTOCOL_GINGLE);
+}
+
+TEST_F(SessionTest, JingleRejection) {
+  TestRejection(PROTOCOL_JINGLE);
+}
+
+TEST_F(SessionTest, GingleGoodRedirect) {
+  TestGoodRedirect(PROTOCOL_GINGLE);
+}
+
+TEST_F(SessionTest, JingleGoodRedirect) {
+  TestGoodRedirect(PROTOCOL_JINGLE);
+}
+
+TEST_F(SessionTest, GingleBadRedirect) {
+  TestBadRedirect(PROTOCOL_GINGLE);
+}
+
+TEST_F(SessionTest, JingleBadRedirect) {
+  TestBadRedirect(PROTOCOL_JINGLE);
+}
+
+TEST_F(SessionTest, TestCandidatesInInitiateAndAccept) {
+  TestCandidatesInInitiateAndAccept("Candidates in initiate/accept");
+}
+
+TEST_F(SessionTest, TestTransportMux) {
+  TestTransportMux();
+}
+
+TEST_F(SessionTest, TestSendDescriptionInfo) {
+  TestSendDescriptionInfo();
+}
+
+TEST_F(SessionTest, TestCallerSignalNewDescription) {
+  TestCallerSignalNewDescription();
+}
+
+TEST_F(SessionTest, TestCalleeSignalNewDescription) {
+  TestCalleeSignalNewDescription();
+}
+
+TEST_F(SessionTest, TestGetTransportStats) {
+  TestGetTransportStats();
+}
diff --git a/webrtc/p2p/base/sessionclient.h b/webrtc/p2p/base/sessionclient.h
new file mode 100644
index 0000000..8968788
--- /dev/null
+++ b/webrtc/p2p/base/sessionclient.h
@@ -0,0 +1,78 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_SESSIONCLIENT_H_
+#define WEBRTC_P2P_BASE_SESSIONCLIENT_H_
+
+#include "webrtc/p2p/base/constants.h"
+
+namespace buzz {
+class XmlElement;
+}
+
+namespace cricket {
+
+struct ParseError;
+class Session;
+class ContentDescription;
+
+class ContentParser {
+ public:
+  virtual bool ParseContent(SignalingProtocol protocol,
+                            const buzz::XmlElement* elem,
+                            ContentDescription** content,
+                            ParseError* error) = 0;
+  // If not IsWriteable, then a given content should be "skipped" when
+  // writing in the given protocol, as if it didn't exist.  We assume
+  // most things are writeable.  We do this to avoid strange cases
+  // like data contents in Gingle, which aren't writable.
+  virtual bool IsWritable(SignalingProtocol protocol,
+                          const ContentDescription* content) {
+    return true;
+  }
+  virtual bool WriteContent(SignalingProtocol protocol,
+                            const ContentDescription* content,
+                            buzz::XmlElement** elem,
+                            WriteError* error) = 0;
+  virtual ~ContentParser() {}
+};
+
+// A SessionClient exists in 1-1 relation with each session.  The implementor
+// of this interface is the one that understands *what* the two sides are
+// trying to send to one another.  The lower-level layers only know how to send
+// data; they do not know what is being sent.
+class SessionClient : public ContentParser {
+ public:
+  // Notifies the client of the creation / destruction of sessions of this type.
+  //
+  // IMPORTANT: The SessionClient, in its handling of OnSessionCreate, must
+  // create whatever channels are indicate in the description.  This is because
+  // the remote client may already be attempting to connect those channels. If
+  // we do not create our channel right away, then connection may fail or be
+  // delayed.
+  virtual void OnSessionCreate(Session* session, bool received_initiate) = 0;
+  virtual void OnSessionDestroy(Session* session) = 0;
+
+  virtual bool ParseContent(SignalingProtocol protocol,
+                            const buzz::XmlElement* elem,
+                            ContentDescription** content,
+                            ParseError* error) = 0;
+  virtual bool WriteContent(SignalingProtocol protocol,
+                            const ContentDescription* content,
+                            buzz::XmlElement** elem,
+                            WriteError* error) = 0;
+ protected:
+  // The SessionClient interface explicitly does not include destructor
+  virtual ~SessionClient() { }
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_SESSIONCLIENT_H_
diff --git a/webrtc/p2p/base/sessiondescription.cc b/webrtc/p2p/base/sessiondescription.cc
new file mode 100644
index 0000000..b05dc51
--- /dev/null
+++ b/webrtc/p2p/base/sessiondescription.cc
@@ -0,0 +1,222 @@
+/*
+ *  Copyright 2010 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/sessiondescription.h"
+
+#include "webrtc/libjingle/xmllite/xmlelement.h"
+
+namespace cricket {
+
+ContentInfo* FindContentInfoByName(
+    ContentInfos& contents, const std::string& name) {
+  for (ContentInfos::iterator content = contents.begin();
+       content != contents.end(); ++content) {
+    if (content->name == name) {
+      return &(*content);
+    }
+  }
+  return NULL;
+}
+
+const ContentInfo* FindContentInfoByName(
+    const ContentInfos& contents, const std::string& name) {
+  for (ContentInfos::const_iterator content = contents.begin();
+       content != contents.end(); ++content) {
+    if (content->name == name) {
+      return &(*content);
+    }
+  }
+  return NULL;
+}
+
+const ContentInfo* FindContentInfoByType(
+    const ContentInfos& contents, const std::string& type) {
+  for (ContentInfos::const_iterator content = contents.begin();
+       content != contents.end(); ++content) {
+    if (content->type == type) {
+      return &(*content);
+    }
+  }
+  return NULL;
+}
+
+const std::string* ContentGroup::FirstContentName() const {
+  return (!content_names_.empty()) ? &(*content_names_.begin()) : NULL;
+}
+
+bool ContentGroup::HasContentName(const std::string& content_name) const {
+  return (std::find(content_names_.begin(), content_names_.end(),
+                    content_name) != content_names_.end());
+}
+
+void ContentGroup::AddContentName(const std::string& content_name) {
+  if (!HasContentName(content_name)) {
+    content_names_.push_back(content_name);
+  }
+}
+
+bool ContentGroup::RemoveContentName(const std::string& content_name) {
+  ContentNames::iterator iter = std::find(
+      content_names_.begin(), content_names_.end(), content_name);
+  if (iter == content_names_.end()) {
+    return false;
+  }
+  content_names_.erase(iter);
+  return true;
+}
+
+SessionDescription* SessionDescription::Copy() const {
+  SessionDescription* copy = new SessionDescription(*this);
+  // Copy all ContentDescriptions.
+  for (ContentInfos::iterator content = copy->contents_.begin();
+      content != copy->contents().end(); ++content) {
+    content->description = content->description->Copy();
+  }
+  return copy;
+}
+
+const ContentInfo* SessionDescription::GetContentByName(
+    const std::string& name) const {
+  return FindContentInfoByName(contents_, name);
+}
+
+ContentInfo* SessionDescription::GetContentByName(
+    const std::string& name)  {
+  return FindContentInfoByName(contents_, name);
+}
+
+const ContentDescription* SessionDescription::GetContentDescriptionByName(
+    const std::string& name) const {
+  const ContentInfo* cinfo = FindContentInfoByName(contents_, name);
+  if (cinfo == NULL) {
+    return NULL;
+  }
+
+  return cinfo->description;
+}
+
+ContentDescription* SessionDescription::GetContentDescriptionByName(
+    const std::string& name) {
+  ContentInfo* cinfo = FindContentInfoByName(contents_, name);
+  if (cinfo == NULL) {
+    return NULL;
+  }
+
+  return cinfo->description;
+}
+
+const ContentInfo* SessionDescription::FirstContentByType(
+    const std::string& type) const {
+  return FindContentInfoByType(contents_, type);
+}
+
+const ContentInfo* SessionDescription::FirstContent() const {
+  return (contents_.empty()) ? NULL : &(*contents_.begin());
+}
+
+void SessionDescription::AddContent(const std::string& name,
+                                    const std::string& type,
+                                    ContentDescription* description) {
+  contents_.push_back(ContentInfo(name, type, description));
+}
+
+void SessionDescription::AddContent(const std::string& name,
+                                    const std::string& type,
+                                    bool rejected,
+                                    ContentDescription* description) {
+  contents_.push_back(ContentInfo(name, type, rejected, description));
+}
+
+bool SessionDescription::RemoveContentByName(const std::string& name) {
+  for (ContentInfos::iterator content = contents_.begin();
+       content != contents_.end(); ++content) {
+    if (content->name == name) {
+      delete content->description;
+      contents_.erase(content);
+      return true;
+    }
+  }
+
+  return false;
+}
+
+bool SessionDescription::AddTransportInfo(const TransportInfo& transport_info) {
+  if (GetTransportInfoByName(transport_info.content_name) != NULL) {
+    return false;
+  }
+  transport_infos_.push_back(transport_info);
+  return true;
+}
+
+bool SessionDescription::RemoveTransportInfoByName(const std::string& name) {
+  for (TransportInfos::iterator transport_info = transport_infos_.begin();
+       transport_info != transport_infos_.end(); ++transport_info) {
+    if (transport_info->content_name == name) {
+      transport_infos_.erase(transport_info);
+      return true;
+    }
+  }
+  return false;
+}
+
+const TransportInfo* SessionDescription::GetTransportInfoByName(
+    const std::string& name) const {
+  for (TransportInfos::const_iterator iter = transport_infos_.begin();
+       iter != transport_infos_.end(); ++iter) {
+    if (iter->content_name == name) {
+      return &(*iter);
+    }
+  }
+  return NULL;
+}
+
+TransportInfo* SessionDescription::GetTransportInfoByName(
+    const std::string& name) {
+  for (TransportInfos::iterator iter = transport_infos_.begin();
+       iter != transport_infos_.end(); ++iter) {
+    if (iter->content_name == name) {
+      return &(*iter);
+    }
+  }
+  return NULL;
+}
+
+void SessionDescription::RemoveGroupByName(const std::string& name) {
+  for (ContentGroups::iterator iter = content_groups_.begin();
+       iter != content_groups_.end(); ++iter) {
+    if (iter->semantics() == name) {
+      content_groups_.erase(iter);
+      break;
+    }
+  }
+}
+
+bool SessionDescription::HasGroup(const std::string& name) const {
+  for (ContentGroups::const_iterator iter = content_groups_.begin();
+       iter != content_groups_.end(); ++iter) {
+    if (iter->semantics() == name) {
+      return true;
+    }
+  }
+  return false;
+}
+
+const ContentGroup* SessionDescription::GetGroupByName(
+    const std::string& name) const {
+  for (ContentGroups::const_iterator iter = content_groups_.begin();
+       iter != content_groups_.end(); ++iter) {
+    if (iter->semantics() == name) {
+      return &(*iter);
+    }
+  }
+  return NULL;
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/sessiondescription.h b/webrtc/p2p/base/sessiondescription.h
new file mode 100644
index 0000000..1182a67
--- /dev/null
+++ b/webrtc/p2p/base/sessiondescription.h
@@ -0,0 +1,185 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_SESSIONDESCRIPTION_H_
+#define WEBRTC_P2P_BASE_SESSIONDESCRIPTION_H_
+
+#include <string>
+#include <vector>
+
+#include "webrtc/p2p/base/transportinfo.h"
+#include "webrtc/base/constructormagic.h"
+
+namespace cricket {
+
+// Describes a session content. Individual content types inherit from
+// this class.  Analagous to a <jingle><content><description> or
+// <session><description>.
+class ContentDescription {
+ public:
+  virtual ~ContentDescription() {}
+  virtual ContentDescription* Copy() const = 0;
+};
+
+// Analagous to a <jingle><content> or <session><description>.
+// name = name of <content name="...">
+// type = xmlns of <content>
+struct ContentInfo {
+  ContentInfo() : description(NULL) {}
+  ContentInfo(const std::string& name,
+              const std::string& type,
+              ContentDescription* description) :
+      name(name), type(type), rejected(false), description(description) {}
+  ContentInfo(const std::string& name,
+              const std::string& type,
+              bool rejected,
+              ContentDescription* description) :
+      name(name), type(type), rejected(rejected), description(description) {}
+  std::string name;
+  std::string type;
+  bool rejected;
+  ContentDescription* description;
+};
+
+typedef std::vector<std::string> ContentNames;
+
+// This class provides a mechanism to aggregate different media contents into a
+// group. This group can also be shared with the peers in a pre-defined format.
+// GroupInfo should be populated only with the |content_name| of the
+// MediaDescription.
+class ContentGroup {
+ public:
+  explicit ContentGroup(const std::string& semantics) :
+      semantics_(semantics) {}
+
+  const std::string& semantics() const { return semantics_; }
+  const ContentNames& content_names() const { return content_names_; }
+
+  const std::string* FirstContentName() const;
+  bool HasContentName(const std::string& content_name) const;
+  void AddContentName(const std::string& content_name);
+  bool RemoveContentName(const std::string& content_name);
+
+ private:
+  std::string semantics_;
+  ContentNames content_names_;
+};
+
+typedef std::vector<ContentInfo> ContentInfos;
+typedef std::vector<ContentGroup> ContentGroups;
+
+const ContentInfo* FindContentInfoByName(
+    const ContentInfos& contents, const std::string& name);
+const ContentInfo* FindContentInfoByType(
+    const ContentInfos& contents, const std::string& type);
+
+// Describes a collection of contents, each with its own name and
+// type.  Analogous to a <jingle> or <session> stanza.  Assumes that
+// contents are unique be name, but doesn't enforce that.
+class SessionDescription {
+ public:
+  SessionDescription() {}
+  explicit SessionDescription(const ContentInfos& contents) :
+      contents_(contents) {}
+  SessionDescription(const ContentInfos& contents,
+                     const ContentGroups& groups) :
+      contents_(contents),
+      content_groups_(groups) {}
+  SessionDescription(const ContentInfos& contents,
+                     const TransportInfos& transports,
+                     const ContentGroups& groups) :
+      contents_(contents),
+      transport_infos_(transports),
+      content_groups_(groups) {}
+  ~SessionDescription() {
+    for (ContentInfos::iterator content = contents_.begin();
+         content != contents_.end(); ++content) {
+      delete content->description;
+    }
+  }
+
+  SessionDescription* Copy() const;
+
+  // Content accessors.
+  const ContentInfos& contents() const { return contents_; }
+  ContentInfos& contents() { return contents_; }
+  const ContentInfo* GetContentByName(const std::string& name) const;
+  ContentInfo* GetContentByName(const std::string& name);
+  const ContentDescription* GetContentDescriptionByName(
+      const std::string& name) const;
+  ContentDescription* GetContentDescriptionByName(const std::string& name);
+  const ContentInfo* FirstContentByType(const std::string& type) const;
+  const ContentInfo* FirstContent() const;
+
+  // Content mutators.
+  // Adds a content to this description. Takes ownership of ContentDescription*.
+  void AddContent(const std::string& name,
+                  const std::string& type,
+                  ContentDescription* description);
+  void AddContent(const std::string& name,
+                  const std::string& type,
+                  bool rejected,
+                  ContentDescription* description);
+  bool RemoveContentByName(const std::string& name);
+
+  // Transport accessors.
+  const TransportInfos& transport_infos() const { return transport_infos_; }
+  TransportInfos& transport_infos() { return transport_infos_; }
+  const TransportInfo* GetTransportInfoByName(
+      const std::string& name) const;
+  TransportInfo* GetTransportInfoByName(const std::string& name);
+  const TransportDescription* GetTransportDescriptionByName(
+      const std::string& name) const {
+    const TransportInfo* tinfo = GetTransportInfoByName(name);
+    return tinfo ? &tinfo->description : NULL;
+  }
+
+  // Transport mutators.
+  void set_transport_infos(const TransportInfos& transport_infos) {
+    transport_infos_ = transport_infos;
+  }
+  // Adds a TransportInfo to this description.
+  // Returns false if a TransportInfo with the same name already exists.
+  bool AddTransportInfo(const TransportInfo& transport_info);
+  bool RemoveTransportInfoByName(const std::string& name);
+
+  // Group accessors.
+  const ContentGroups& groups() const { return content_groups_; }
+  const ContentGroup* GetGroupByName(const std::string& name) const;
+  bool HasGroup(const std::string& name) const;
+
+  // Group mutators.
+  void AddGroup(const ContentGroup& group) { content_groups_.push_back(group); }
+  // Remove the first group with the same semantics specified by |name|.
+  void RemoveGroupByName(const std::string& name);
+
+ private:
+  ContentInfos contents_;
+  TransportInfos transport_infos_;
+  ContentGroups content_groups_;
+};
+
+// Indicates whether a ContentDescription was an offer or an answer, as
+// described in http://www.ietf.org/rfc/rfc3264.txt. CA_UPDATE
+// indicates a jingle update message which contains a subset of a full
+// session description
+enum ContentAction {
+  CA_OFFER, CA_PRANSWER, CA_ANSWER, CA_UPDATE
+};
+
+// Indicates whether a ContentDescription was sent by the local client
+// or received from the remote client.
+enum ContentSource {
+  CS_LOCAL, CS_REMOTE
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_SESSIONDESCRIPTION_H_
diff --git a/webrtc/p2p/base/sessionid.h b/webrtc/p2p/base/sessionid.h
new file mode 100644
index 0000000..f695700
--- /dev/null
+++ b/webrtc/p2p/base/sessionid.h
@@ -0,0 +1,20 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_SESSIONID_H_
+#define WEBRTC_P2P_BASE_SESSIONID_H_
+
+// TODO: Remove this file.
+
+namespace cricket {
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_SESSIONID_H_
diff --git a/webrtc/p2p/base/sessionmanager.cc b/webrtc/p2p/base/sessionmanager.cc
new file mode 100644
index 0000000..f375dea
--- /dev/null
+++ b/webrtc/p2p/base/sessionmanager.cc
@@ -0,0 +1,309 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/sessionmanager.h"
+
+#include "webrtc/p2p/base/constants.h"
+#include "webrtc/p2p/base/session.h"
+#include "webrtc/p2p/base/sessionmessages.h"
+#include "webrtc/libjingle/xmpp/constants.h"
+#include "webrtc/libjingle/xmpp/jid.h"
+#include "webrtc/base/common.h"
+#include "webrtc/base/helpers.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/stringencode.h"
+
+namespace cricket {
+
+SessionManager::SessionManager(PortAllocator *allocator,
+                               rtc::Thread *worker) {
+  allocator_ = allocator;
+  signaling_thread_ = rtc::Thread::Current();
+  if (worker == NULL) {
+    worker_thread_ = rtc::Thread::Current();
+  } else {
+    worker_thread_ = worker;
+  }
+  timeout_ = 50;
+}
+
+SessionManager::~SessionManager() {
+  // Note: Session::Terminate occurs asynchronously, so it's too late to
+  // delete them now.  They better be all gone.
+  ASSERT(session_map_.empty());
+  // TerminateAll();
+  SignalDestroyed();
+}
+
+void SessionManager::AddClient(const std::string& content_type,
+                               SessionClient* client) {
+  ASSERT(client_map_.find(content_type) == client_map_.end());
+  client_map_[content_type] = client;
+}
+
+void SessionManager::RemoveClient(const std::string& content_type) {
+  ClientMap::iterator iter = client_map_.find(content_type);
+  ASSERT(iter != client_map_.end());
+  client_map_.erase(iter);
+}
+
+SessionClient* SessionManager::GetClient(const std::string& content_type) {
+  ClientMap::iterator iter = client_map_.find(content_type);
+  return (iter != client_map_.end()) ? iter->second : NULL;
+}
+
+Session* SessionManager::CreateSession(const std::string& local_name,
+                                       const std::string& content_type) {
+  std::string id;
+  return CreateSession(id, local_name, content_type);
+}
+
+Session* SessionManager::CreateSession(const std::string& id,
+                                       const std::string& local_name,
+                                       const std::string& content_type) {
+  std::string sid =
+      id.empty() ? rtc::ToString(rtc::CreateRandomId64()) : id;
+  return CreateSession(local_name, local_name, sid, content_type, false);
+}
+
+Session* SessionManager::CreateSession(
+    const std::string& local_name, const std::string& initiator_name,
+    const std::string& sid, const std::string& content_type,
+    bool received_initiate) {
+  SessionClient* client = GetClient(content_type);
+  ASSERT(client != NULL);
+
+  Session* session = new Session(this, local_name, initiator_name,
+                                 sid, content_type, client);
+  session->SetIdentity(transport_desc_factory_.identity());
+  session_map_[session->id()] = session;
+  session->SignalRequestSignaling.connect(
+      this, &SessionManager::OnRequestSignaling);
+  session->SignalOutgoingMessage.connect(
+      this, &SessionManager::OnOutgoingMessage);
+  session->SignalErrorMessage.connect(this, &SessionManager::OnErrorMessage);
+  SignalSessionCreate(session, received_initiate);
+  session->client()->OnSessionCreate(session, received_initiate);
+  return session;
+}
+
+void SessionManager::DestroySession(Session* session) {
+  if (session != NULL) {
+    SessionMap::iterator it = session_map_.find(session->id());
+    if (it != session_map_.end()) {
+      SignalSessionDestroy(session);
+      session->client()->OnSessionDestroy(session);
+      session_map_.erase(it);
+      delete session;
+    }
+  }
+}
+
+Session* SessionManager::GetSession(const std::string& sid) {
+  SessionMap::iterator it = session_map_.find(sid);
+  if (it != session_map_.end())
+    return it->second;
+  return NULL;
+}
+
+void SessionManager::TerminateAll() {
+  while (session_map_.begin() != session_map_.end()) {
+    Session* session = session_map_.begin()->second;
+    session->Terminate();
+  }
+}
+
+bool SessionManager::IsSessionMessage(const buzz::XmlElement* stanza) {
+  return cricket::IsSessionMessage(stanza);
+}
+
+Session* SessionManager::FindSession(const std::string& sid,
+                                     const std::string& remote_name) {
+  SessionMap::iterator iter = session_map_.find(sid);
+  if (iter == session_map_.end())
+    return NULL;
+
+  Session* session = iter->second;
+  if (buzz::Jid(remote_name) != buzz::Jid(session->remote_name()))
+    return NULL;
+
+  return session;
+}
+
+void SessionManager::OnIncomingMessage(const buzz::XmlElement* stanza) {
+  SessionMessage msg;
+  ParseError error;
+
+  if (!ParseSessionMessage(stanza, &msg, &error)) {
+    SendErrorMessage(stanza, buzz::QN_STANZA_BAD_REQUEST, "modify",
+                     error.text, NULL);
+    return;
+  }
+
+  Session* session = FindSession(msg.sid, msg.from);
+  if (session) {
+    session->OnIncomingMessage(msg);
+    return;
+  }
+  if (msg.type != ACTION_SESSION_INITIATE) {
+    SendErrorMessage(stanza, buzz::QN_STANZA_BAD_REQUEST, "modify",
+                     "unknown session", NULL);
+    return;
+  }
+
+  std::string content_type;
+  if (!ParseContentType(msg.protocol, msg.action_elem,
+                        &content_type, &error)) {
+    SendErrorMessage(stanza, buzz::QN_STANZA_BAD_REQUEST, "modify",
+                     error.text, NULL);
+    return;
+  }
+
+  if (!GetClient(content_type)) {
+    SendErrorMessage(stanza, buzz::QN_STANZA_BAD_REQUEST, "modify",
+                     "unknown content type: " + content_type, NULL);
+    return;
+  }
+
+  session = CreateSession(msg.to, msg.initiator, msg.sid,
+                          content_type, true);
+  session->OnIncomingMessage(msg);
+}
+
+void SessionManager::OnIncomingResponse(const buzz::XmlElement* orig_stanza,
+    const buzz::XmlElement* response_stanza) {
+  if (orig_stanza == NULL || response_stanza == NULL) {
+    return;
+  }
+
+  SessionMessage msg;
+  ParseError error;
+  if (!ParseSessionMessage(orig_stanza, &msg, &error)) {
+    LOG(LS_WARNING) << "Error parsing incoming response: " << error.text
+                    << ":" << orig_stanza;
+    return;
+  }
+
+  Session* session = FindSession(msg.sid, msg.to);
+  if (!session) {
+    // Also try the QN_FROM in the response stanza, in case we sent the request
+    // to a bare JID but got the response from a full JID.
+    std::string ack_from = response_stanza->Attr(buzz::QN_FROM);
+    session = FindSession(msg.sid, ack_from);
+  }
+  if (session) {
+    session->OnIncomingResponse(orig_stanza, response_stanza, msg);
+  }
+}
+
+void SessionManager::OnFailedSend(const buzz::XmlElement* orig_stanza,
+                                  const buzz::XmlElement* error_stanza) {
+  SessionMessage msg;
+  ParseError error;
+  if (!ParseSessionMessage(orig_stanza, &msg, &error)) {
+    return;  // TODO: log somewhere?
+  }
+
+  Session* session = FindSession(msg.sid, msg.to);
+  if (session) {
+    rtc::scoped_ptr<buzz::XmlElement> synthetic_error;
+    if (!error_stanza) {
+      // A failed send is semantically equivalent to an error response, so we
+      // can just turn the former into the latter.
+      synthetic_error.reset(
+        CreateErrorMessage(orig_stanza, buzz::QN_STANZA_ITEM_NOT_FOUND,
+                           "cancel", "Recipient did not respond", NULL));
+      error_stanza = synthetic_error.get();
+    }
+
+    session->OnFailedSend(orig_stanza, error_stanza);
+  }
+}
+
+void SessionManager::SendErrorMessage(const buzz::XmlElement* stanza,
+                                      const buzz::QName& name,
+                                      const std::string& type,
+                                      const std::string& text,
+                                      const buzz::XmlElement* extra_info) {
+  rtc::scoped_ptr<buzz::XmlElement> msg(
+      CreateErrorMessage(stanza, name, type, text, extra_info));
+  SignalOutgoingMessage(this, msg.get());
+}
+
+buzz::XmlElement* SessionManager::CreateErrorMessage(
+    const buzz::XmlElement* stanza,
+    const buzz::QName& name,
+    const std::string& type,
+    const std::string& text,
+    const buzz::XmlElement* extra_info) {
+  buzz::XmlElement* iq = new buzz::XmlElement(buzz::QN_IQ);
+  iq->SetAttr(buzz::QN_TO, stanza->Attr(buzz::QN_FROM));
+  iq->SetAttr(buzz::QN_ID, stanza->Attr(buzz::QN_ID));
+  iq->SetAttr(buzz::QN_TYPE, "error");
+
+  CopyXmlChildren(stanza, iq);
+
+  buzz::XmlElement* error = new buzz::XmlElement(buzz::QN_ERROR);
+  error->SetAttr(buzz::QN_TYPE, type);
+  iq->AddElement(error);
+
+  // If the error name is not in the standard namespace, we have to first add
+  // some error from that namespace.
+  if (name.Namespace() != buzz::NS_STANZA) {
+     error->AddElement(
+         new buzz::XmlElement(buzz::QN_STANZA_UNDEFINED_CONDITION));
+  }
+  error->AddElement(new buzz::XmlElement(name));
+
+  if (extra_info)
+    error->AddElement(new buzz::XmlElement(*extra_info));
+
+  if (text.size() > 0) {
+    // It's okay to always use English here.  This text is for debugging
+    // purposes only.
+    buzz::XmlElement* text_elem = new buzz::XmlElement(buzz::QN_STANZA_TEXT);
+    text_elem->SetAttr(buzz::QN_XML_LANG, "en");
+    text_elem->SetBodyText(text);
+    error->AddElement(text_elem);
+  }
+
+  // TODO: Should we include error codes as well for SIP compatibility?
+
+  return iq;
+}
+
+void SessionManager::OnOutgoingMessage(Session* session,
+                                       const buzz::XmlElement* stanza) {
+  SignalOutgoingMessage(this, stanza);
+}
+
+void SessionManager::OnErrorMessage(BaseSession* session,
+                                    const buzz::XmlElement* stanza,
+                                    const buzz::QName& name,
+                                    const std::string& type,
+                                    const std::string& text,
+                                    const buzz::XmlElement* extra_info) {
+  SendErrorMessage(stanza, name, type, text, extra_info);
+}
+
+void SessionManager::OnSignalingReady() {
+  for (SessionMap::iterator it = session_map_.begin();
+      it != session_map_.end();
+      ++it) {
+    it->second->OnSignalingReady();
+  }
+}
+
+void SessionManager::OnRequestSignaling(Session* session) {
+  SignalRequestSignaling();
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/sessionmanager.h b/webrtc/p2p/base/sessionmanager.h
new file mode 100644
index 0000000..74ee5c0
--- /dev/null
+++ b/webrtc/p2p/base/sessionmanager.h
@@ -0,0 +1,194 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_SESSIONMANAGER_H_
+#define WEBRTC_P2P_BASE_SESSIONMANAGER_H_
+
+#include <map>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "webrtc/p2p/base/portallocator.h"
+#include "webrtc/p2p/base/transportdescriptionfactory.h"
+#include "webrtc/base/sigslot.h"
+#include "webrtc/base/thread.h"
+
+namespace buzz {
+class QName;
+class XmlElement;
+}
+
+namespace cricket {
+
+class Session;
+class BaseSession;
+class SessionClient;
+
+// SessionManager manages session instances.
+class SessionManager : public sigslot::has_slots<> {
+ public:
+  SessionManager(PortAllocator *allocator,
+                 rtc::Thread *worker_thread = NULL);
+  virtual ~SessionManager();
+
+  PortAllocator *port_allocator() const { return allocator_; }
+  rtc::Thread *worker_thread() const { return worker_thread_; }
+  rtc::Thread *signaling_thread() const { return signaling_thread_; }
+
+  int session_timeout() const { return timeout_; }
+  void set_session_timeout(int timeout) { timeout_ = timeout; }
+
+  // Set what transport protocol we want to default to.
+  void set_transport_protocol(TransportProtocol proto) {
+     transport_desc_factory_.set_protocol(proto);
+  }
+
+  // Control use of DTLS. An identity must be supplied if DTLS is enabled.
+  void set_secure(SecurePolicy policy) {
+    transport_desc_factory_.set_secure(policy);
+  }
+  void set_identity(rtc::SSLIdentity* identity) {
+    transport_desc_factory_.set_identity(identity);
+  }
+  const TransportDescriptionFactory* transport_desc_factory() const {
+    return &transport_desc_factory_;
+  }
+
+  // Registers support for the given client.  If we receive an initiate
+  // describing a session of the given type, we will automatically create a
+  // Session object and notify this client.  The client may then accept or
+  // reject the session.
+  void AddClient(const std::string& content_type, SessionClient* client);
+  void RemoveClient(const std::string& content_type);
+  SessionClient* GetClient(const std::string& content_type);
+
+  // Creates a new session.  The given name is the JID of the client on whose
+  // behalf we initiate the session.
+  Session *CreateSession(const std::string& local_name,
+                         const std::string& content_type);
+
+  Session *CreateSession(const std::string& id,
+                         const std::string& local_name,
+                         const std::string& content_type);
+
+  // Destroys the given session.
+  void DestroySession(Session *session);
+
+  // Returns the session with the given ID or NULL if none exists.
+  Session *GetSession(const std::string& sid);
+
+  // Terminates all of the sessions created by this manager.
+  void TerminateAll();
+
+  // These are signaled whenever the set of existing sessions changes.
+  sigslot::signal2<Session *, bool> SignalSessionCreate;
+  sigslot::signal1<Session *> SignalSessionDestroy;
+
+  // Determines whether the given stanza is intended for some session.
+  bool IsSessionMessage(const buzz::XmlElement* stanza);
+
+  // Given a sid, initiator, and remote_name, this finds the matching Session
+  Session* FindSession(const std::string& sid,
+                       const std::string& remote_name);
+
+  // Called when we receive a stanza for which IsSessionMessage is true.
+  void OnIncomingMessage(const buzz::XmlElement* stanza);
+
+  // Called when we get a response to a message that we sent.
+  void OnIncomingResponse(const buzz::XmlElement* orig_stanza,
+                          const buzz::XmlElement* response_stanza);
+
+  // Called if an attempted to send times out or an error is returned.  In the
+  // timeout case error_stanza will be NULL
+  void OnFailedSend(const buzz::XmlElement* orig_stanza,
+                    const buzz::XmlElement* error_stanza);
+
+  // Signalled each time a session generates a signaling message to send.
+  // Also signalled on errors, but with a NULL session.
+  sigslot::signal2<SessionManager*,
+                   const buzz::XmlElement*> SignalOutgoingMessage;
+
+  // Signaled before sessions try to send certain signaling messages.  The
+  // client should call OnSignalingReady once it is safe to send them.  These
+  // steps are taken so that we don't send signaling messages trying to
+  // re-establish the connectivity of a session when the client cannot send
+  // the messages (and would probably just drop them on the floor).
+  //
+  // Note: you can connect this directly to OnSignalingReady(), if a signalling
+  // check is not supported.
+  sigslot::signal0<> SignalRequestSignaling;
+  void OnSignalingReady();
+
+  // Signaled when this SessionManager is deleted.
+  sigslot::signal0<> SignalDestroyed;
+
+ private:
+  typedef std::map<std::string, Session*> SessionMap;
+  typedef std::map<std::string, SessionClient*> ClientMap;
+
+  // Helper function for CreateSession.  This is also invoked when we receive
+  // a message attempting to initiate a session with this client.
+  Session *CreateSession(const std::string& local_name,
+                         const std::string& initiator,
+                         const std::string& sid,
+                         const std::string& content_type,
+                         bool received_initiate);
+
+  // Attempts to find a registered session type whose description appears as
+  // a child of the session element.  Such a child should be present indicating
+  // the application they hope to initiate.
+  std::string FindClient(const buzz::XmlElement* session);
+
+  // Sends a message back to the other client indicating that we found an error
+  // in the stanza they sent.  name identifies the error, type is one of the
+  // standard XMPP types (cancel, continue, modify, auth, wait), and text is a
+  // description for debugging purposes.
+  void SendErrorMessage(const buzz::XmlElement* stanza,
+                        const buzz::QName& name,
+                        const std::string& type,
+                        const std::string& text,
+                        const buzz::XmlElement* extra_info);
+
+  // Creates and returns an error message from the given components.  The
+  // caller is responsible for deleting this.
+  buzz::XmlElement* CreateErrorMessage(
+      const buzz::XmlElement* stanza,
+      const buzz::QName& name,
+      const std::string& type,
+      const std::string& text,
+      const buzz::XmlElement* extra_info);
+
+  // Called each time a session requests signaling.
+  void OnRequestSignaling(Session* session);
+
+  // Called each time a session has an outgoing message.
+  void OnOutgoingMessage(Session* session, const buzz::XmlElement* stanza);
+
+  // Called each time a session has an error to send.
+  void OnErrorMessage(BaseSession* session,
+                      const buzz::XmlElement* stanza,
+                      const buzz::QName& name,
+                      const std::string& type,
+                      const std::string& text,
+                      const buzz::XmlElement* extra_info);
+
+  PortAllocator *allocator_;
+  rtc::Thread *signaling_thread_;
+  rtc::Thread *worker_thread_;
+  int timeout_;
+  TransportDescriptionFactory transport_desc_factory_;
+  SessionMap session_map_;
+  ClientMap client_map_;
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_SESSIONMANAGER_H_
diff --git a/webrtc/p2p/base/sessionmessages.cc b/webrtc/p2p/base/sessionmessages.cc
new file mode 100644
index 0000000..cc63673
--- /dev/null
+++ b/webrtc/p2p/base/sessionmessages.cc
@@ -0,0 +1,1132 @@
+/*
+ *  Copyright 2010 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/sessionmessages.h"
+
+#include <stdio.h>
+#include <string>
+
+#include "webrtc/p2p/base/constants.h"
+#include "webrtc/p2p/base/p2ptransport.h"
+#include "webrtc/p2p/base/parsing.h"
+#include "webrtc/p2p/base/sessionclient.h"
+#include "webrtc/p2p/base/sessiondescription.h"
+#include "webrtc/p2p/base/transport.h"
+#include "webrtc/libjingle/xmllite/xmlconstants.h"
+#include "webrtc/libjingle/xmpp/constants.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/stringutils.h"
+
+namespace cricket {
+
+ActionType ToActionType(const std::string& type) {
+  if (type == GINGLE_ACTION_INITIATE)
+    return ACTION_SESSION_INITIATE;
+  if (type == GINGLE_ACTION_INFO)
+    return ACTION_SESSION_INFO;
+  if (type == GINGLE_ACTION_ACCEPT)
+    return ACTION_SESSION_ACCEPT;
+  if (type == GINGLE_ACTION_REJECT)
+    return ACTION_SESSION_REJECT;
+  if (type == GINGLE_ACTION_TERMINATE)
+    return ACTION_SESSION_TERMINATE;
+  if (type == GINGLE_ACTION_CANDIDATES)
+    return ACTION_TRANSPORT_INFO;
+  if (type == JINGLE_ACTION_SESSION_INITIATE)
+    return ACTION_SESSION_INITIATE;
+  if (type == JINGLE_ACTION_TRANSPORT_INFO)
+    return ACTION_TRANSPORT_INFO;
+  if (type == JINGLE_ACTION_TRANSPORT_ACCEPT)
+    return ACTION_TRANSPORT_ACCEPT;
+  if (type == JINGLE_ACTION_SESSION_INFO)
+    return ACTION_SESSION_INFO;
+  if (type == JINGLE_ACTION_SESSION_ACCEPT)
+    return ACTION_SESSION_ACCEPT;
+  if (type == JINGLE_ACTION_SESSION_TERMINATE)
+    return ACTION_SESSION_TERMINATE;
+  if (type == JINGLE_ACTION_TRANSPORT_INFO)
+    return ACTION_TRANSPORT_INFO;
+  if (type == JINGLE_ACTION_TRANSPORT_ACCEPT)
+    return ACTION_TRANSPORT_ACCEPT;
+  if (type == JINGLE_ACTION_DESCRIPTION_INFO)
+    return ACTION_DESCRIPTION_INFO;
+  if (type == GINGLE_ACTION_UPDATE)
+    return ACTION_DESCRIPTION_INFO;
+
+  return ACTION_UNKNOWN;
+}
+
+std::string ToJingleString(ActionType type) {
+  switch (type) {
+    case ACTION_SESSION_INITIATE:
+      return JINGLE_ACTION_SESSION_INITIATE;
+    case ACTION_SESSION_INFO:
+      return JINGLE_ACTION_SESSION_INFO;
+    case ACTION_DESCRIPTION_INFO:
+      return JINGLE_ACTION_DESCRIPTION_INFO;
+    case ACTION_SESSION_ACCEPT:
+      return JINGLE_ACTION_SESSION_ACCEPT;
+    // Notice that reject and terminate both go to
+    // "session-terminate", but there is no "session-reject".
+    case ACTION_SESSION_REJECT:
+    case ACTION_SESSION_TERMINATE:
+      return JINGLE_ACTION_SESSION_TERMINATE;
+    case ACTION_TRANSPORT_INFO:
+      return JINGLE_ACTION_TRANSPORT_INFO;
+    case ACTION_TRANSPORT_ACCEPT:
+      return JINGLE_ACTION_TRANSPORT_ACCEPT;
+    default:
+      return "";
+  }
+}
+
+std::string ToGingleString(ActionType type) {
+  switch (type) {
+    case ACTION_SESSION_INITIATE:
+      return GINGLE_ACTION_INITIATE;
+    case ACTION_SESSION_INFO:
+      return GINGLE_ACTION_INFO;
+    case ACTION_SESSION_ACCEPT:
+      return GINGLE_ACTION_ACCEPT;
+    case ACTION_SESSION_REJECT:
+      return GINGLE_ACTION_REJECT;
+    case ACTION_SESSION_TERMINATE:
+      return GINGLE_ACTION_TERMINATE;
+    case ACTION_TRANSPORT_INFO:
+      return GINGLE_ACTION_CANDIDATES;
+    default:
+      return "";
+  }
+}
+
+
+bool IsJingleMessage(const buzz::XmlElement* stanza) {
+  const buzz::XmlElement* jingle = stanza->FirstNamed(QN_JINGLE);
+  if (jingle == NULL)
+    return false;
+
+  return (jingle->HasAttr(buzz::QN_ACTION) && jingle->HasAttr(QN_SID));
+}
+
+bool IsGingleMessage(const buzz::XmlElement* stanza) {
+  const buzz::XmlElement* session = stanza->FirstNamed(QN_GINGLE_SESSION);
+  if (session == NULL)
+    return false;
+
+  return (session->HasAttr(buzz::QN_TYPE) &&
+          session->HasAttr(buzz::QN_ID)   &&
+          session->HasAttr(QN_INITIATOR));
+}
+
+bool IsSessionMessage(const buzz::XmlElement* stanza) {
+  return (stanza->Name() == buzz::QN_IQ &&
+          stanza->Attr(buzz::QN_TYPE) == buzz::STR_SET &&
+          (IsJingleMessage(stanza) ||
+           IsGingleMessage(stanza)));
+}
+
+bool ParseGingleSessionMessage(const buzz::XmlElement* session,
+                               SessionMessage* msg,
+                               ParseError* error) {
+  msg->protocol = PROTOCOL_GINGLE;
+  std::string type_string = session->Attr(buzz::QN_TYPE);
+  msg->type = ToActionType(type_string);
+  msg->sid = session->Attr(buzz::QN_ID);
+  msg->initiator = session->Attr(QN_INITIATOR);
+  msg->action_elem = session;
+
+  if (msg->type == ACTION_UNKNOWN)
+    return BadParse("unknown action: " + type_string, error);
+
+  return true;
+}
+
+bool ParseJingleSessionMessage(const buzz::XmlElement* jingle,
+                               SessionMessage* msg,
+                               ParseError* error) {
+  msg->protocol = PROTOCOL_JINGLE;
+  std::string type_string = jingle->Attr(buzz::QN_ACTION);
+  msg->type = ToActionType(type_string);
+  msg->sid = jingle->Attr(QN_SID);
+  msg->initiator = GetXmlAttr(jingle, QN_INITIATOR, buzz::STR_EMPTY);
+  msg->action_elem = jingle;
+
+  if (msg->type == ACTION_UNKNOWN)
+    return BadParse("unknown action: " + type_string, error);
+
+  return true;
+}
+
+bool ParseHybridSessionMessage(const buzz::XmlElement* jingle,
+                               SessionMessage* msg,
+                               ParseError* error) {
+  if (!ParseJingleSessionMessage(jingle, msg, error))
+    return false;
+  msg->protocol = PROTOCOL_HYBRID;
+
+  return true;
+}
+
+bool ParseSessionMessage(const buzz::XmlElement* stanza,
+                         SessionMessage* msg,
+                         ParseError* error) {
+  msg->id = stanza->Attr(buzz::QN_ID);
+  msg->from = stanza->Attr(buzz::QN_FROM);
+  msg->to = stanza->Attr(buzz::QN_TO);
+  msg->stanza = stanza;
+
+  const buzz::XmlElement* jingle = stanza->FirstNamed(QN_JINGLE);
+  const buzz::XmlElement* session = stanza->FirstNamed(QN_GINGLE_SESSION);
+  if (jingle && session)
+    return ParseHybridSessionMessage(jingle, msg, error);
+  if (jingle != NULL)
+    return ParseJingleSessionMessage(jingle, msg, error);
+  if (session != NULL)
+    return ParseGingleSessionMessage(session, msg, error);
+  return false;
+}
+
+buzz::XmlElement* WriteGingleAction(const SessionMessage& msg,
+                                    const XmlElements& action_elems) {
+  buzz::XmlElement* session = new buzz::XmlElement(QN_GINGLE_SESSION, true);
+  session->AddAttr(buzz::QN_TYPE, ToGingleString(msg.type));
+  session->AddAttr(buzz::QN_ID, msg.sid);
+  session->AddAttr(QN_INITIATOR, msg.initiator);
+  AddXmlChildren(session, action_elems);
+  return session;
+}
+
+buzz::XmlElement* WriteJingleAction(const SessionMessage& msg,
+                                    const XmlElements& action_elems) {
+  buzz::XmlElement* jingle = new buzz::XmlElement(QN_JINGLE, true);
+  jingle->AddAttr(buzz::QN_ACTION, ToJingleString(msg.type));
+  jingle->AddAttr(QN_SID, msg.sid);
+  if (msg.type == ACTION_SESSION_INITIATE) {
+    jingle->AddAttr(QN_INITIATOR, msg.initiator);
+  }
+  AddXmlChildren(jingle, action_elems);
+  return jingle;
+}
+
+void WriteSessionMessage(const SessionMessage& msg,
+                         const XmlElements& action_elems,
+                         buzz::XmlElement* stanza) {
+  stanza->SetAttr(buzz::QN_TO, msg.to);
+  stanza->SetAttr(buzz::QN_TYPE, buzz::STR_SET);
+
+  if (msg.protocol == PROTOCOL_GINGLE) {
+    stanza->AddElement(WriteGingleAction(msg, action_elems));
+  } else {
+    stanza->AddElement(WriteJingleAction(msg, action_elems));
+  }
+}
+
+
+TransportParser* GetTransportParser(const TransportParserMap& trans_parsers,
+                                    const std::string& transport_type) {
+  TransportParserMap::const_iterator map = trans_parsers.find(transport_type);
+  if (map == trans_parsers.end()) {
+    return NULL;
+  } else {
+    return map->second;
+  }
+}
+
+CandidateTranslator* GetCandidateTranslator(
+    const CandidateTranslatorMap& translators,
+    const std::string& content_name) {
+  CandidateTranslatorMap::const_iterator map = translators.find(content_name);
+  if (map == translators.end()) {
+    return NULL;
+  } else {
+    return map->second;
+  }
+}
+
+bool GetParserAndTranslator(const TransportParserMap& trans_parsers,
+                            const CandidateTranslatorMap& translators,
+                            const std::string& transport_type,
+                            const std::string& content_name,
+                            TransportParser** parser,
+                            CandidateTranslator** translator,
+                            ParseError* error) {
+  *parser = GetTransportParser(trans_parsers, transport_type);
+  if (*parser == NULL) {
+    return BadParse("unknown transport type: " + transport_type, error);
+  }
+  // Not having a translator isn't fatal when parsing. If this is called for an
+  // initiate message, we won't have our proxies set up to do the translation.
+  // Fortunately, for the cases where translation is needed, candidates are
+  // never sent in initiates.
+  *translator = GetCandidateTranslator(translators, content_name);
+  return true;
+}
+
+bool GetParserAndTranslator(const TransportParserMap& trans_parsers,
+                            const CandidateTranslatorMap& translators,
+                            const std::string& transport_type,
+                            const std::string& content_name,
+                            TransportParser** parser,
+                            CandidateTranslator** translator,
+                            WriteError* error) {
+  *parser = GetTransportParser(trans_parsers, transport_type);
+  if (*parser == NULL) {
+    return BadWrite("unknown transport type: " + transport_type, error);
+  }
+  *translator = GetCandidateTranslator(translators, content_name);
+  if (*translator == NULL) {
+    return BadWrite("unknown content name: " + content_name, error);
+  }
+  return true;
+}
+
+bool ParseGingleCandidate(const buzz::XmlElement* candidate_elem,
+                          const TransportParserMap& trans_parsers,
+                          const CandidateTranslatorMap& translators,
+                          const std::string& content_name,
+                          Candidates* candidates,
+                          ParseError* error) {
+  TransportParser* trans_parser;
+  CandidateTranslator* translator;
+  if (!GetParserAndTranslator(trans_parsers, translators,
+                              NS_GINGLE_P2P, content_name,
+                              &trans_parser, &translator, error))
+    return false;
+
+  Candidate candidate;
+  if (!trans_parser->ParseGingleCandidate(
+          candidate_elem, translator, &candidate, error)) {
+    return false;
+  }
+
+  candidates->push_back(candidate);
+  return true;
+}
+
+bool ParseGingleCandidates(const buzz::XmlElement* parent,
+                           const TransportParserMap& trans_parsers,
+                           const CandidateTranslatorMap& translators,
+                           const std::string& content_name,
+                           Candidates* candidates,
+                           ParseError* error) {
+  for (const buzz::XmlElement* candidate_elem = parent->FirstElement();
+       candidate_elem != NULL;
+       candidate_elem = candidate_elem->NextElement()) {
+    if (candidate_elem->Name().LocalPart() == LN_CANDIDATE) {
+      if (!ParseGingleCandidate(candidate_elem, trans_parsers, translators,
+                                content_name, candidates, error)) {
+        return false;
+      }
+    }
+  }
+  return true;
+}
+
+bool ParseGingleTransportInfos(const buzz::XmlElement* action_elem,
+                               const ContentInfos& contents,
+                               const TransportParserMap& trans_parsers,
+                               const CandidateTranslatorMap& translators,
+                               TransportInfos* tinfos,
+                               ParseError* error) {
+  bool has_audio = FindContentInfoByName(contents, CN_AUDIO) != NULL;
+  bool has_video = FindContentInfoByName(contents, CN_VIDEO) != NULL;
+
+  // If we don't have media, no need to separate the candidates.
+  if (!has_audio && !has_video) {
+    TransportInfo tinfo(CN_OTHER,
+        TransportDescription(NS_GINGLE_P2P, std::string(), std::string()));
+    if (!ParseGingleCandidates(action_elem, trans_parsers, translators,
+                               CN_OTHER, &tinfo.description.candidates,
+                               error)) {
+      return false;
+    }
+
+    tinfos->push_back(tinfo);
+    return true;
+  }
+
+  // If we have media, separate the candidates.
+  TransportInfo audio_tinfo(
+      CN_AUDIO,
+      TransportDescription(NS_GINGLE_P2P, std::string(), std::string()));
+  TransportInfo video_tinfo(
+      CN_VIDEO,
+      TransportDescription(NS_GINGLE_P2P, std::string(), std::string()));
+  for (const buzz::XmlElement* candidate_elem = action_elem->FirstElement();
+       candidate_elem != NULL;
+       candidate_elem = candidate_elem->NextElement()) {
+    if (candidate_elem->Name().LocalPart() == LN_CANDIDATE) {
+      const std::string& channel_name = candidate_elem->Attr(buzz::QN_NAME);
+      if (has_audio &&
+          (channel_name == GICE_CHANNEL_NAME_RTP ||
+           channel_name == GICE_CHANNEL_NAME_RTCP)) {
+        if (!ParseGingleCandidate(
+                candidate_elem, trans_parsers,
+                translators, CN_AUDIO,
+                &audio_tinfo.description.candidates, error)) {
+          return false;
+        }
+      } else if (has_video &&
+                 (channel_name == GICE_CHANNEL_NAME_VIDEO_RTP ||
+                  channel_name == GICE_CHANNEL_NAME_VIDEO_RTCP)) {
+        if (!ParseGingleCandidate(
+                candidate_elem, trans_parsers,
+                translators, CN_VIDEO,
+                &video_tinfo.description.candidates, error)) {
+          return false;
+        }
+      } else {
+        return BadParse("Unknown channel name: " + channel_name, error);
+      }
+    }
+  }
+
+  if (has_audio) {
+    tinfos->push_back(audio_tinfo);
+  }
+  if (has_video) {
+    tinfos->push_back(video_tinfo);
+  }
+  return true;
+}
+
+bool ParseJingleTransportInfo(const buzz::XmlElement* trans_elem,
+                              const std::string& content_name,
+                              const TransportParserMap& trans_parsers,
+                              const CandidateTranslatorMap& translators,
+                              TransportInfo* tinfo,
+                              ParseError* error) {
+  TransportParser* trans_parser;
+  CandidateTranslator* translator;
+  if (!GetParserAndTranslator(trans_parsers, translators,
+                              trans_elem->Name().Namespace(), content_name,
+                              &trans_parser, &translator, error))
+    return false;
+
+  TransportDescription tdesc;
+  if (!trans_parser->ParseTransportDescription(trans_elem, translator,
+                                               &tdesc, error))
+    return false;
+
+  *tinfo = TransportInfo(content_name, tdesc);
+  return true;
+}
+
+bool ParseJingleTransportInfos(const buzz::XmlElement* jingle,
+                               const ContentInfos& contents,
+                               const TransportParserMap trans_parsers,
+                               const CandidateTranslatorMap& translators,
+                               TransportInfos* tinfos,
+                               ParseError* error) {
+  for (const buzz::XmlElement* pair_elem
+           = jingle->FirstNamed(QN_JINGLE_CONTENT);
+       pair_elem != NULL;
+       pair_elem = pair_elem->NextNamed(QN_JINGLE_CONTENT)) {
+    std::string content_name;
+    if (!RequireXmlAttr(pair_elem, QN_JINGLE_CONTENT_NAME,
+                        &content_name, error))
+      return false;
+
+    const ContentInfo* content = FindContentInfoByName(contents, content_name);
+    if (!content)
+      return BadParse("Unknown content name: " + content_name, error);
+
+    const buzz::XmlElement* trans_elem;
+    if (!RequireXmlChild(pair_elem, LN_TRANSPORT, &trans_elem, error))
+      return false;
+
+    TransportInfo tinfo;
+    if (!ParseJingleTransportInfo(trans_elem, content->name,
+                                  trans_parsers, translators,
+                                  &tinfo, error))
+      return false;
+
+    tinfos->push_back(tinfo);
+  }
+
+  return true;
+}
+
+buzz::XmlElement* NewTransportElement(const std::string& name) {
+  return new buzz::XmlElement(buzz::QName(name, LN_TRANSPORT), true);
+}
+
+bool WriteGingleCandidates(const Candidates& candidates,
+                           const TransportParserMap& trans_parsers,
+                           const std::string& transport_type,
+                           const CandidateTranslatorMap& translators,
+                           const std::string& content_name,
+                           XmlElements* elems,
+                           WriteError* error) {
+  TransportParser* trans_parser;
+  CandidateTranslator* translator;
+  if (!GetParserAndTranslator(trans_parsers, translators,
+                              transport_type, content_name,
+                              &trans_parser, &translator, error))
+    return false;
+
+  for (size_t i = 0; i < candidates.size(); ++i) {
+    rtc::scoped_ptr<buzz::XmlElement> element;
+    if (!trans_parser->WriteGingleCandidate(candidates[i], translator,
+                                            element.accept(), error)) {
+      return false;
+    }
+
+    elems->push_back(element.release());
+  }
+
+  return true;
+}
+
+bool WriteGingleTransportInfos(const TransportInfos& tinfos,
+                               const TransportParserMap& trans_parsers,
+                               const CandidateTranslatorMap& translators,
+                               XmlElements* elems,
+                               WriteError* error) {
+  for (TransportInfos::const_iterator tinfo = tinfos.begin();
+       tinfo != tinfos.end(); ++tinfo) {
+    if (!WriteGingleCandidates(tinfo->description.candidates,
+                               trans_parsers, tinfo->description.transport_type,
+                               translators, tinfo->content_name,
+                               elems, error))
+      return false;
+  }
+
+  return true;
+}
+
+bool WriteJingleTransportInfo(const TransportInfo& tinfo,
+                              const TransportParserMap& trans_parsers,
+                              const CandidateTranslatorMap& translators,
+                              XmlElements* elems,
+                              WriteError* error) {
+  std::string transport_type = tinfo.description.transport_type;
+  TransportParser* trans_parser;
+  CandidateTranslator* translator;
+  if (!GetParserAndTranslator(trans_parsers, translators,
+                              transport_type, tinfo.content_name,
+                              &trans_parser, &translator, error))
+    return false;
+
+  buzz::XmlElement* trans_elem;
+  if (!trans_parser->WriteTransportDescription(tinfo.description, translator,
+                                               &trans_elem, error)) {
+    return false;
+  }
+
+  elems->push_back(trans_elem);
+  return true;
+}
+
+void WriteJingleContent(const std::string name,
+                        const XmlElements& child_elems,
+                        XmlElements* elems) {
+  buzz::XmlElement* content_elem = new buzz::XmlElement(QN_JINGLE_CONTENT);
+  content_elem->SetAttr(QN_JINGLE_CONTENT_NAME, name);
+  content_elem->SetAttr(QN_CREATOR, LN_INITIATOR);
+  AddXmlChildren(content_elem, child_elems);
+
+  elems->push_back(content_elem);
+}
+
+bool WriteJingleTransportInfos(const TransportInfos& tinfos,
+                               const TransportParserMap& trans_parsers,
+                               const CandidateTranslatorMap& translators,
+                               XmlElements* elems,
+                               WriteError* error) {
+  for (TransportInfos::const_iterator tinfo = tinfos.begin();
+       tinfo != tinfos.end(); ++tinfo) {
+    XmlElements content_child_elems;
+    if (!WriteJingleTransportInfo(*tinfo, trans_parsers, translators,
+                                  &content_child_elems, error))
+
+      return false;
+
+    WriteJingleContent(tinfo->content_name, content_child_elems, elems);
+  }
+
+  return true;
+}
+
+ContentParser* GetContentParser(const ContentParserMap& content_parsers,
+                                const std::string& type) {
+  ContentParserMap::const_iterator map = content_parsers.find(type);
+  if (map == content_parsers.end()) {
+    return NULL;
+  } else {
+    return map->second;
+  }
+}
+
+bool ParseContentInfo(SignalingProtocol protocol,
+                      const std::string& name,
+                      const std::string& type,
+                      const buzz::XmlElement* elem,
+                      const ContentParserMap& parsers,
+                      ContentInfos* contents,
+                      ParseError* error) {
+  ContentParser* parser = GetContentParser(parsers, type);
+  if (parser == NULL)
+    return BadParse("unknown application content: " + type, error);
+
+  ContentDescription* desc;
+  if (!parser->ParseContent(protocol, elem, &desc, error))
+    return false;
+
+  contents->push_back(ContentInfo(name, type, desc));
+  return true;
+}
+
+bool ParseContentType(const buzz::XmlElement* parent_elem,
+                      std::string* content_type,
+                      const buzz::XmlElement** content_elem,
+                      ParseError* error) {
+  if (!RequireXmlChild(parent_elem, LN_DESCRIPTION, content_elem, error))
+    return false;
+
+  *content_type = (*content_elem)->Name().Namespace();
+  return true;
+}
+
+bool ParseGingleContentInfos(const buzz::XmlElement* session,
+                             const ContentParserMap& content_parsers,
+                             ContentInfos* contents,
+                             ParseError* error) {
+  std::string content_type;
+  const buzz::XmlElement* content_elem;
+  if (!ParseContentType(session, &content_type, &content_elem, error))
+    return false;
+
+  if (content_type == NS_GINGLE_VIDEO) {
+    // A parser parsing audio or video content should look at the
+    // namespace and only parse the codecs relevant to that namespace.
+    // We use this to control which codecs get parsed: first audio,
+    // then video.
+    rtc::scoped_ptr<buzz::XmlElement> audio_elem(
+        new buzz::XmlElement(QN_GINGLE_AUDIO_CONTENT));
+    CopyXmlChildren(content_elem, audio_elem.get());
+    if (!ParseContentInfo(PROTOCOL_GINGLE, CN_AUDIO, NS_JINGLE_RTP,
+                          audio_elem.get(), content_parsers,
+                          contents, error))
+      return false;
+
+    if (!ParseContentInfo(PROTOCOL_GINGLE, CN_VIDEO, NS_JINGLE_RTP,
+                          content_elem, content_parsers,
+                          contents, error))
+      return false;
+  } else if (content_type == NS_GINGLE_AUDIO) {
+    if (!ParseContentInfo(PROTOCOL_GINGLE, CN_AUDIO, NS_JINGLE_RTP,
+                          content_elem, content_parsers,
+                          contents, error))
+      return false;
+  } else {
+    if (!ParseContentInfo(PROTOCOL_GINGLE, CN_OTHER, content_type,
+                          content_elem, content_parsers,
+                          contents, error))
+      return false;
+  }
+  return true;
+}
+
+bool ParseJingleContentInfos(const buzz::XmlElement* jingle,
+                             const ContentParserMap& content_parsers,
+                             ContentInfos* contents,
+                             ParseError* error) {
+  for (const buzz::XmlElement* pair_elem
+           = jingle->FirstNamed(QN_JINGLE_CONTENT);
+       pair_elem != NULL;
+       pair_elem = pair_elem->NextNamed(QN_JINGLE_CONTENT)) {
+    std::string content_name;
+    if (!RequireXmlAttr(pair_elem, QN_JINGLE_CONTENT_NAME,
+                        &content_name, error))
+      return false;
+
+    std::string content_type;
+    const buzz::XmlElement* content_elem;
+    if (!ParseContentType(pair_elem, &content_type, &content_elem, error))
+      return false;
+
+    if (!ParseContentInfo(PROTOCOL_JINGLE, content_name, content_type,
+                          content_elem, content_parsers,
+                          contents, error))
+      return false;
+  }
+  return true;
+}
+
+bool ParseJingleGroupInfos(const buzz::XmlElement* jingle,
+                           ContentGroups* groups,
+                           ParseError* error) {
+  for (const buzz::XmlElement* pair_elem
+           = jingle->FirstNamed(QN_JINGLE_DRAFT_GROUP);
+       pair_elem != NULL;
+       pair_elem = pair_elem->NextNamed(QN_JINGLE_DRAFT_GROUP)) {
+    std::string group_name;
+    if (!RequireXmlAttr(pair_elem, QN_JINGLE_DRAFT_GROUP_TYPE,
+                        &group_name, error))
+      return false;
+
+    ContentGroup group(group_name);
+    for (const buzz::XmlElement* child_elem
+             = pair_elem->FirstNamed(QN_JINGLE_CONTENT);
+        child_elem != NULL;
+        child_elem = child_elem->NextNamed(QN_JINGLE_CONTENT)) {
+      std::string content_name;
+      if (!RequireXmlAttr(child_elem, QN_JINGLE_CONTENT_NAME,
+                          &content_name, error))
+        return false;
+      group.AddContentName(content_name);
+    }
+    groups->push_back(group);
+  }
+  return true;
+}
+
+buzz::XmlElement* WriteContentInfo(SignalingProtocol protocol,
+                                   const ContentInfo& content,
+                                   const ContentParserMap& parsers,
+                                   WriteError* error) {
+  ContentParser* parser = GetContentParser(parsers, content.type);
+  if (parser == NULL) {
+    BadWrite("unknown content type: " + content.type, error);
+    return NULL;
+  }
+
+  buzz::XmlElement* elem = NULL;
+  if (!parser->WriteContent(protocol, content.description, &elem, error))
+    return NULL;
+
+  return elem;
+}
+
+bool IsWritable(SignalingProtocol protocol,
+                const ContentInfo& content,
+                const ContentParserMap& parsers) {
+  ContentParser* parser = GetContentParser(parsers, content.type);
+  if (parser == NULL) {
+    return false;
+  }
+
+  return parser->IsWritable(protocol, content.description);
+}
+
+bool WriteGingleContentInfos(const ContentInfos& contents,
+                             const ContentParserMap& parsers,
+                             XmlElements* elems,
+                             WriteError* error) {
+  if (contents.size() == 1 ||
+      (contents.size() == 2 &&
+       !IsWritable(PROTOCOL_GINGLE, contents.at(1), parsers))) {
+    if (contents.front().rejected) {
+      return BadWrite("Gingle protocol may not reject individual contents.",
+                      error);
+    }
+    buzz::XmlElement* elem = WriteContentInfo(
+        PROTOCOL_GINGLE, contents.front(), parsers, error);
+    if (!elem)
+      return false;
+
+    elems->push_back(elem);
+  } else if (contents.size() >= 2 &&
+             contents.at(0).type == NS_JINGLE_RTP &&
+             contents.at(1).type == NS_JINGLE_RTP) {
+     // Special-case audio + video contents so that they are "merged"
+     // into one "video" content.
+    if (contents.at(0).rejected || contents.at(1).rejected) {
+      return BadWrite("Gingle protocol may not reject individual contents.",
+                      error);
+    }
+    buzz::XmlElement* audio = WriteContentInfo(
+        PROTOCOL_GINGLE, contents.at(0), parsers, error);
+    if (!audio)
+      return false;
+
+    buzz::XmlElement* video = WriteContentInfo(
+        PROTOCOL_GINGLE, contents.at(1), parsers, error);
+    if (!video) {
+      delete audio;
+      return false;
+    }
+
+    CopyXmlChildren(audio, video);
+    elems->push_back(video);
+    delete audio;
+  } else {
+    return BadWrite("Gingle protocol may only have one content.", error);
+  }
+
+  return true;
+}
+
+const TransportInfo* GetTransportInfoByContentName(
+    const TransportInfos& tinfos, const std::string& content_name) {
+  for (TransportInfos::const_iterator tinfo = tinfos.begin();
+       tinfo != tinfos.end(); ++tinfo) {
+    if (content_name == tinfo->content_name) {
+      return &*tinfo;
+    }
+  }
+  return NULL;
+}
+
+bool WriteJingleContents(const ContentInfos& contents,
+                         const ContentParserMap& content_parsers,
+                         const TransportInfos& tinfos,
+                         const TransportParserMap& trans_parsers,
+                         const CandidateTranslatorMap& translators,
+                         XmlElements* elems,
+                         WriteError* error) {
+  for (ContentInfos::const_iterator content = contents.begin();
+       content != contents.end(); ++content) {
+    if (content->rejected) {
+      continue;
+    }
+    const TransportInfo* tinfo =
+        GetTransportInfoByContentName(tinfos, content->name);
+    if (!tinfo)
+      return BadWrite("No transport for content: " + content->name, error);
+
+    XmlElements pair_elems;
+    buzz::XmlElement* elem = WriteContentInfo(
+        PROTOCOL_JINGLE, *content, content_parsers, error);
+    if (!elem)
+      return false;
+    pair_elems.push_back(elem);
+
+    if (!WriteJingleTransportInfo(*tinfo, trans_parsers, translators,
+                                  &pair_elems, error))
+      return false;
+
+    WriteJingleContent(content->name, pair_elems, elems);
+  }
+  return true;
+}
+
+bool WriteJingleContentInfos(const ContentInfos& contents,
+                             const ContentParserMap& content_parsers,
+                             XmlElements* elems,
+                             WriteError* error) {
+  for (ContentInfos::const_iterator content = contents.begin();
+       content != contents.end(); ++content) {
+    if (content->rejected) {
+      continue;
+    }
+    XmlElements content_child_elems;
+    buzz::XmlElement* elem = WriteContentInfo(
+        PROTOCOL_JINGLE, *content, content_parsers, error);
+    if (!elem)
+      return false;
+    content_child_elems.push_back(elem);
+    WriteJingleContent(content->name, content_child_elems, elems);
+  }
+  return true;
+}
+
+bool WriteJingleGroupInfo(const ContentInfos& contents,
+                          const ContentGroups& groups,
+                          XmlElements* elems,
+                          WriteError* error) {
+  if (!groups.empty()) {
+    buzz::XmlElement* pair_elem = new buzz::XmlElement(QN_JINGLE_DRAFT_GROUP);
+    pair_elem->SetAttr(QN_JINGLE_DRAFT_GROUP_TYPE, GROUP_TYPE_BUNDLE);
+
+    XmlElements pair_elems;
+    for (ContentInfos::const_iterator content = contents.begin();
+         content != contents.end(); ++content) {
+      buzz::XmlElement* child_elem =
+          new buzz::XmlElement(QN_JINGLE_CONTENT, false);
+      child_elem->SetAttr(QN_JINGLE_CONTENT_NAME, content->name);
+      pair_elems.push_back(child_elem);
+    }
+    AddXmlChildren(pair_elem, pair_elems);
+    elems->push_back(pair_elem);
+  }
+  return true;
+}
+
+bool ParseContentType(SignalingProtocol protocol,
+                      const buzz::XmlElement* action_elem,
+                      std::string* content_type,
+                      ParseError* error) {
+  const buzz::XmlElement* content_elem;
+  if (protocol == PROTOCOL_GINGLE) {
+    if (!ParseContentType(action_elem, content_type, &content_elem, error))
+      return false;
+
+    // Internally, we only use NS_JINGLE_RTP.
+    if (*content_type == NS_GINGLE_AUDIO ||
+        *content_type == NS_GINGLE_VIDEO)
+      *content_type = NS_JINGLE_RTP;
+  } else {
+    const buzz::XmlElement* pair_elem
+        = action_elem->FirstNamed(QN_JINGLE_CONTENT);
+    if (pair_elem == NULL)
+      return BadParse("No contents found", error);
+
+    if (!ParseContentType(pair_elem, content_type, &content_elem, error))
+      return false;
+  }
+
+  return true;
+}
+
+static bool ParseContentMessage(
+    SignalingProtocol protocol,
+    const buzz::XmlElement* action_elem,
+    bool expect_transports,
+    const ContentParserMap& content_parsers,
+    const TransportParserMap& trans_parsers,
+    const CandidateTranslatorMap& translators,
+    SessionInitiate* init,
+    ParseError* error) {
+  init->owns_contents = true;
+  if (protocol == PROTOCOL_GINGLE) {
+    if (!ParseGingleContentInfos(action_elem, content_parsers,
+                                 &init->contents, error))
+      return false;
+
+    if (expect_transports &&
+        !ParseGingleTransportInfos(action_elem, init->contents,
+                                   trans_parsers, translators,
+                                   &init->transports, error))
+      return false;
+  } else {
+    if (!ParseJingleContentInfos(action_elem, content_parsers,
+                                 &init->contents, error))
+      return false;
+    if (!ParseJingleGroupInfos(action_elem, &init->groups, error))
+      return false;
+
+    if (expect_transports &&
+        !ParseJingleTransportInfos(action_elem, init->contents,
+                                   trans_parsers, translators,
+                                   &init->transports, error))
+      return false;
+  }
+
+  return true;
+}
+
+static bool WriteContentMessage(
+    SignalingProtocol protocol,
+    const ContentInfos& contents,
+    const TransportInfos& tinfos,
+    const ContentParserMap& content_parsers,
+    const TransportParserMap& transport_parsers,
+    const CandidateTranslatorMap& translators,
+    const ContentGroups& groups,
+    XmlElements* elems,
+    WriteError* error) {
+  if (protocol == PROTOCOL_GINGLE) {
+    if (!WriteGingleContentInfos(contents, content_parsers, elems, error))
+      return false;
+
+    if (!WriteGingleTransportInfos(tinfos, transport_parsers, translators,
+                                   elems, error))
+      return false;
+  } else {
+    if (!WriteJingleContents(contents, content_parsers,
+                             tinfos, transport_parsers, translators,
+                             elems, error))
+      return false;
+    if (!WriteJingleGroupInfo(contents, groups, elems, error))
+      return false;
+  }
+
+  return true;
+}
+
+bool ParseSessionInitiate(SignalingProtocol protocol,
+                          const buzz::XmlElement* action_elem,
+                          const ContentParserMap& content_parsers,
+                          const TransportParserMap& trans_parsers,
+                          const CandidateTranslatorMap& translators,
+                          SessionInitiate* init,
+                          ParseError* error) {
+  bool expect_transports = true;
+  return ParseContentMessage(protocol, action_elem, expect_transports,
+                             content_parsers, trans_parsers, translators,
+                             init, error);
+}
+
+
+bool WriteSessionInitiate(SignalingProtocol protocol,
+                          const ContentInfos& contents,
+                          const TransportInfos& tinfos,
+                          const ContentParserMap& content_parsers,
+                          const TransportParserMap& transport_parsers,
+                          const CandidateTranslatorMap& translators,
+                          const ContentGroups& groups,
+                          XmlElements* elems,
+                          WriteError* error) {
+  return WriteContentMessage(protocol, contents, tinfos,
+                             content_parsers, transport_parsers, translators,
+                             groups,
+                             elems, error);
+}
+
+bool ParseSessionAccept(SignalingProtocol protocol,
+                        const buzz::XmlElement* action_elem,
+                        const ContentParserMap& content_parsers,
+                        const TransportParserMap& transport_parsers,
+                        const CandidateTranslatorMap& translators,
+                        SessionAccept* accept,
+                        ParseError* error) {
+  bool expect_transports = true;
+  return ParseContentMessage(protocol, action_elem, expect_transports,
+                             content_parsers, transport_parsers, translators,
+                             accept, error);
+}
+
+bool WriteSessionAccept(SignalingProtocol protocol,
+                        const ContentInfos& contents,
+                        const TransportInfos& tinfos,
+                        const ContentParserMap& content_parsers,
+                        const TransportParserMap& transport_parsers,
+                        const CandidateTranslatorMap& translators,
+                        const ContentGroups& groups,
+                        XmlElements* elems,
+                        WriteError* error) {
+  return WriteContentMessage(protocol, contents, tinfos,
+                             content_parsers, transport_parsers, translators,
+                             groups,
+                             elems, error);
+}
+
+bool ParseSessionTerminate(SignalingProtocol protocol,
+                           const buzz::XmlElement* action_elem,
+                           SessionTerminate* term,
+                           ParseError* error) {
+  if (protocol == PROTOCOL_GINGLE) {
+    const buzz::XmlElement* reason_elem = action_elem->FirstElement();
+    if (reason_elem != NULL) {
+      term->reason = reason_elem->Name().LocalPart();
+      const buzz::XmlElement *debug_elem = reason_elem->FirstElement();
+      if (debug_elem != NULL) {
+        term->debug_reason = debug_elem->Name().LocalPart();
+      }
+    }
+    return true;
+  } else {
+    const buzz::XmlElement* reason_elem =
+        action_elem->FirstNamed(QN_JINGLE_REASON);
+    if (reason_elem) {
+      reason_elem = reason_elem->FirstElement();
+      if (reason_elem) {
+        term->reason = reason_elem->Name().LocalPart();
+      }
+    }
+    return true;
+  }
+}
+
+void WriteSessionTerminate(SignalingProtocol protocol,
+                           const SessionTerminate& term,
+                           XmlElements* elems) {
+  if (protocol == PROTOCOL_GINGLE) {
+    elems->push_back(new buzz::XmlElement(buzz::QName(NS_GINGLE, term.reason)));
+  } else {
+    if (!term.reason.empty()) {
+      buzz::XmlElement* reason_elem = new buzz::XmlElement(QN_JINGLE_REASON);
+      reason_elem->AddElement(new buzz::XmlElement(
+          buzz::QName(NS_JINGLE, term.reason)));
+      elems->push_back(reason_elem);
+    }
+  }
+}
+
+bool ParseDescriptionInfo(SignalingProtocol protocol,
+                          const buzz::XmlElement* action_elem,
+                          const ContentParserMap& content_parsers,
+                          const TransportParserMap& transport_parsers,
+                          const CandidateTranslatorMap& translators,
+                          DescriptionInfo* description_info,
+                          ParseError* error) {
+  bool expect_transports = false;
+  return ParseContentMessage(protocol, action_elem, expect_transports,
+                             content_parsers, transport_parsers, translators,
+                             description_info, error);
+}
+
+bool WriteDescriptionInfo(SignalingProtocol protocol,
+                          const ContentInfos& contents,
+                          const ContentParserMap& content_parsers,
+                          XmlElements* elems,
+                          WriteError* error) {
+  if (protocol == PROTOCOL_GINGLE) {
+    return WriteGingleContentInfos(contents, content_parsers, elems, error);
+  } else {
+    return WriteJingleContentInfos(contents, content_parsers, elems, error);
+  }
+}
+
+bool ParseTransportInfos(SignalingProtocol protocol,
+                         const buzz::XmlElement* action_elem,
+                         const ContentInfos& contents,
+                         const TransportParserMap& trans_parsers,
+                         const CandidateTranslatorMap& translators,
+                         TransportInfos* tinfos,
+                         ParseError* error) {
+  if (protocol == PROTOCOL_GINGLE) {
+    return ParseGingleTransportInfos(
+        action_elem, contents, trans_parsers, translators, tinfos, error);
+  } else {
+    return ParseJingleTransportInfos(
+        action_elem, contents, trans_parsers, translators, tinfos, error);
+  }
+}
+
+bool WriteTransportInfos(SignalingProtocol protocol,
+                         const TransportInfos& tinfos,
+                         const TransportParserMap& trans_parsers,
+                         const CandidateTranslatorMap& translators,
+                         XmlElements* elems,
+                         WriteError* error) {
+  if (protocol == PROTOCOL_GINGLE) {
+    return WriteGingleTransportInfos(tinfos, trans_parsers, translators,
+                                     elems, error);
+  } else {
+    return WriteJingleTransportInfos(tinfos, trans_parsers, translators,
+                                     elems, error);
+  }
+}
+
+bool GetUriTarget(const std::string& prefix, const std::string& str,
+                  std::string* after) {
+  size_t pos = str.find(prefix);
+  if (pos == std::string::npos)
+    return false;
+
+  *after = str.substr(pos + prefix.size(), std::string::npos);
+  return true;
+}
+
+bool FindSessionRedirect(const buzz::XmlElement* stanza,
+                         SessionRedirect* redirect) {
+  const buzz::XmlElement* error_elem = GetXmlChild(stanza, LN_ERROR);
+  if (error_elem == NULL)
+    return false;
+
+  const buzz::XmlElement* redirect_elem =
+      error_elem->FirstNamed(QN_GINGLE_REDIRECT);
+  if (redirect_elem == NULL)
+    redirect_elem = error_elem->FirstNamed(buzz::QN_STANZA_REDIRECT);
+  if (redirect_elem == NULL)
+    return false;
+
+  if (!GetUriTarget(STR_REDIRECT_PREFIX, redirect_elem->BodyText(),
+                    &redirect->target))
+    return false;
+
+  return true;
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/sessionmessages.h b/webrtc/p2p/base/sessionmessages.h
new file mode 100644
index 0000000..7b156d4
--- /dev/null
+++ b/webrtc/p2p/base/sessionmessages.h
@@ -0,0 +1,226 @@
+/*
+ *  Copyright 2010 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_SESSIONMESSAGES_H_
+#define WEBRTC_P2P_BASE_SESSIONMESSAGES_H_
+
+#include <map>
+#include <string>
+#include <vector>
+
+#include "webrtc/p2p/base/constants.h"
+#include "webrtc/p2p/base/parsing.h"
+#include "webrtc/p2p/base/sessiondescription.h"  // Needed to delete contents.
+#include "webrtc/p2p/base/transportinfo.h"
+#include "webrtc/libjingle/xmllite/xmlelement.h"
+#include "webrtc/base/basictypes.h"
+
+namespace cricket {
+
+struct ParseError;
+struct WriteError;
+class Candidate;
+class ContentParser;
+class TransportParser;
+
+typedef std::vector<Candidate> Candidates;
+typedef std::map<std::string, ContentParser*> ContentParserMap;
+typedef std::map<std::string, TransportParser*> TransportParserMap;
+
+enum ActionType {
+  ACTION_UNKNOWN,
+
+  ACTION_SESSION_INITIATE,
+  ACTION_SESSION_INFO,
+  ACTION_SESSION_ACCEPT,
+  ACTION_SESSION_REJECT,
+  ACTION_SESSION_TERMINATE,
+
+  ACTION_TRANSPORT_INFO,
+  ACTION_TRANSPORT_ACCEPT,
+
+  ACTION_DESCRIPTION_INFO,
+};
+
+// Abstraction of a <jingle> element within an <iq> stanza, per XMPP
+// standard XEP-166.  Can be serialized into multiple protocols,
+// including the standard (Jingle) and the draft standard (Gingle).
+// In general, used to communicate actions related to a p2p session,
+// such accept, initiate, terminate, etc.
+
+struct SessionMessage {
+  SessionMessage() : action_elem(NULL), stanza(NULL) {}
+
+  SessionMessage(SignalingProtocol protocol, ActionType type,
+                 const std::string& sid, const std::string& initiator) :
+      protocol(protocol), type(type), sid(sid), initiator(initiator),
+      action_elem(NULL), stanza(NULL) {}
+
+  std::string id;
+  std::string from;
+  std::string to;
+  SignalingProtocol protocol;
+  ActionType type;
+  std::string sid;  // session id
+  std::string initiator;
+
+  // Used for further parsing when necessary.
+  // Represents <session> or <jingle>.
+  const buzz::XmlElement* action_elem;
+  // Mostly used for debugging.
+  const buzz::XmlElement* stanza;
+};
+
+// TODO: Break up this class so we don't have to typedef it into
+// different classes.
+struct ContentMessage {
+  ContentMessage() : owns_contents(false) {}
+
+  ~ContentMessage() {
+    if (owns_contents) {
+      for (ContentInfos::iterator content = contents.begin();
+           content != contents.end(); content++) {
+        delete content->description;
+      }
+    }
+  }
+
+  // Caller takes ownership of contents.
+  ContentInfos ClearContents() {
+    ContentInfos out;
+    contents.swap(out);
+    owns_contents = false;
+    return out;
+  }
+
+  bool owns_contents;
+  ContentInfos contents;
+  TransportInfos transports;
+  ContentGroups groups;
+};
+
+typedef ContentMessage SessionInitiate;
+typedef ContentMessage SessionAccept;
+// Note that a DescriptionInfo does not have TransportInfos.
+typedef ContentMessage DescriptionInfo;
+
+struct SessionTerminate {
+  SessionTerminate() {}
+
+  explicit SessionTerminate(const std::string& reason) :
+      reason(reason) {}
+
+  std::string reason;
+  std::string debug_reason;
+};
+
+struct SessionRedirect {
+  std::string target;
+};
+
+// Used during parsing and writing to map component to channel name
+// and back.  This is primarily for converting old G-ICE candidate
+// signalling to new ICE candidate classes.
+class CandidateTranslator {
+ public:
+  virtual bool GetChannelNameFromComponent(
+      int component, std::string* channel_name) const = 0;
+  virtual bool GetComponentFromChannelName(
+      const std::string& channel_name, int* component) const = 0;
+};
+
+// Content name => translator
+typedef std::map<std::string, CandidateTranslator*> CandidateTranslatorMap;
+
+bool IsSessionMessage(const buzz::XmlElement* stanza);
+bool ParseSessionMessage(const buzz::XmlElement* stanza,
+                         SessionMessage* msg,
+                         ParseError* error);
+// Will return an error if there is more than one content type.
+bool ParseContentType(SignalingProtocol protocol,
+                      const buzz::XmlElement* action_elem,
+                      std::string* content_type,
+                      ParseError* error);
+void WriteSessionMessage(const SessionMessage& msg,
+                         const XmlElements& action_elems,
+                         buzz::XmlElement* stanza);
+bool ParseSessionInitiate(SignalingProtocol protocol,
+                          const buzz::XmlElement* action_elem,
+                          const ContentParserMap& content_parsers,
+                          const TransportParserMap& transport_parsers,
+                          const CandidateTranslatorMap& translators,
+                          SessionInitiate* init,
+                          ParseError* error);
+bool WriteSessionInitiate(SignalingProtocol protocol,
+                          const ContentInfos& contents,
+                          const TransportInfos& tinfos,
+                          const ContentParserMap& content_parsers,
+                          const TransportParserMap& transport_parsers,
+                          const CandidateTranslatorMap& translators,
+                          const ContentGroups& groups,
+                          XmlElements* elems,
+                          WriteError* error);
+bool ParseSessionAccept(SignalingProtocol protocol,
+                        const buzz::XmlElement* action_elem,
+                        const ContentParserMap& content_parsers,
+                        const TransportParserMap& transport_parsers,
+                        const CandidateTranslatorMap& translators,
+                        SessionAccept* accept,
+                        ParseError* error);
+bool WriteSessionAccept(SignalingProtocol protocol,
+                        const ContentInfos& contents,
+                        const TransportInfos& tinfos,
+                        const ContentParserMap& content_parsers,
+                        const TransportParserMap& transport_parsers,
+                        const CandidateTranslatorMap& translators,
+                        const ContentGroups& groups,
+                        XmlElements* elems,
+                        WriteError* error);
+bool ParseSessionTerminate(SignalingProtocol protocol,
+                           const buzz::XmlElement* action_elem,
+                           SessionTerminate* term,
+                           ParseError* error);
+void WriteSessionTerminate(SignalingProtocol protocol,
+                           const SessionTerminate& term,
+                           XmlElements* elems);
+bool ParseDescriptionInfo(SignalingProtocol protocol,
+                          const buzz::XmlElement* action_elem,
+                          const ContentParserMap& content_parsers,
+                          const TransportParserMap& transport_parsers,
+                          const CandidateTranslatorMap& translators,
+                          DescriptionInfo* description_info,
+                          ParseError* error);
+bool WriteDescriptionInfo(SignalingProtocol protocol,
+                          const ContentInfos& contents,
+                          const ContentParserMap& content_parsers,
+                          XmlElements* elems,
+                          WriteError* error);
+// Since a TransportInfo is not a transport-info message, and a
+// transport-info message is just a collection of TransportInfos, we
+// say Parse/Write TransportInfos for transport-info messages.
+bool ParseTransportInfos(SignalingProtocol protocol,
+                         const buzz::XmlElement* action_elem,
+                         const ContentInfos& contents,
+                         const TransportParserMap& trans_parsers,
+                         const CandidateTranslatorMap& translators,
+                         TransportInfos* tinfos,
+                         ParseError* error);
+bool WriteTransportInfos(SignalingProtocol protocol,
+                         const TransportInfos& tinfos,
+                         const TransportParserMap& trans_parsers,
+                         const CandidateTranslatorMap& translators,
+                         XmlElements* elems,
+                         WriteError* error);
+// Handles both Gingle and Jingle syntax.
+bool FindSessionRedirect(const buzz::XmlElement* stanza,
+                         SessionRedirect* redirect);
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_SESSIONMESSAGES_H_
diff --git a/webrtc/p2p/base/stun.cc b/webrtc/p2p/base/stun.cc
new file mode 100644
index 0000000..60367fa
--- /dev/null
+++ b/webrtc/p2p/base/stun.cc
@@ -0,0 +1,915 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/stun.h"
+
+#include <string.h>
+
+#include "webrtc/base/byteorder.h"
+#include "webrtc/base/common.h"
+#include "webrtc/base/crc32.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/messagedigest.h"
+#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/stringencode.h"
+
+using rtc::ByteBuffer;
+
+namespace cricket {
+
+const char STUN_ERROR_REASON_TRY_ALTERNATE_SERVER[] = "Try Alternate Server";
+const char STUN_ERROR_REASON_BAD_REQUEST[] = "Bad Request";
+const char STUN_ERROR_REASON_UNAUTHORIZED[] = "Unauthorized";
+const char STUN_ERROR_REASON_FORBIDDEN[] = "Forbidden";
+const char STUN_ERROR_REASON_STALE_CREDENTIALS[] = "Stale Credentials";
+const char STUN_ERROR_REASON_ALLOCATION_MISMATCH[] = "Allocation Mismatch";
+const char STUN_ERROR_REASON_STALE_NONCE[] = "Stale Nonce";
+const char STUN_ERROR_REASON_WRONG_CREDENTIALS[] = "Wrong Credentials";
+const char STUN_ERROR_REASON_UNSUPPORTED_PROTOCOL[] = "Unsupported Protocol";
+const char STUN_ERROR_REASON_ROLE_CONFLICT[] = "Role Conflict";
+const char STUN_ERROR_REASON_SERVER_ERROR[] = "Server Error";
+
+const char TURN_MAGIC_COOKIE_VALUE[] = { '\x72', '\xC6', '\x4B', '\xC6' };
+const char EMPTY_TRANSACTION_ID[] = "0000000000000000";
+const uint32 STUN_FINGERPRINT_XOR_VALUE = 0x5354554E;
+
+// StunMessage
+
+StunMessage::StunMessage()
+    : type_(0),
+      length_(0),
+      transaction_id_(EMPTY_TRANSACTION_ID) {
+  ASSERT(IsValidTransactionId(transaction_id_));
+  attrs_ = new std::vector<StunAttribute*>();
+}
+
+StunMessage::~StunMessage() {
+  for (size_t i = 0; i < attrs_->size(); i++)
+    delete (*attrs_)[i];
+  delete attrs_;
+}
+
+bool StunMessage::IsLegacy() const {
+  if (transaction_id_.size() == kStunLegacyTransactionIdLength)
+    return true;
+  ASSERT(transaction_id_.size() == kStunTransactionIdLength);
+  return false;
+}
+
+bool StunMessage::SetTransactionID(const std::string& str) {
+  if (!IsValidTransactionId(str)) {
+    return false;
+  }
+  transaction_id_ = str;
+  return true;
+}
+
+bool StunMessage::AddAttribute(StunAttribute* attr) {
+  // Fail any attributes that aren't valid for this type of message.
+  if (attr->value_type() != GetAttributeValueType(attr->type())) {
+    return false;
+  }
+  attrs_->push_back(attr);
+  attr->SetOwner(this);
+  size_t attr_length = attr->length();
+  if (attr_length % 4 != 0) {
+    attr_length += (4 - (attr_length % 4));
+  }
+  length_ += static_cast<uint16>(attr_length + 4);
+  return true;
+}
+
+const StunAddressAttribute* StunMessage::GetAddress(int type) const {
+  switch (type) {
+    case STUN_ATTR_MAPPED_ADDRESS: {
+      // Return XOR-MAPPED-ADDRESS when MAPPED-ADDRESS attribute is
+      // missing.
+      const StunAttribute* mapped_address =
+          GetAttribute(STUN_ATTR_MAPPED_ADDRESS);
+      if (!mapped_address)
+        mapped_address = GetAttribute(STUN_ATTR_XOR_MAPPED_ADDRESS);
+      return reinterpret_cast<const StunAddressAttribute*>(mapped_address);
+    }
+
+    default:
+      return static_cast<const StunAddressAttribute*>(GetAttribute(type));
+  }
+}
+
+const StunUInt32Attribute* StunMessage::GetUInt32(int type) const {
+  return static_cast<const StunUInt32Attribute*>(GetAttribute(type));
+}
+
+const StunUInt64Attribute* StunMessage::GetUInt64(int type) const {
+  return static_cast<const StunUInt64Attribute*>(GetAttribute(type));
+}
+
+const StunByteStringAttribute* StunMessage::GetByteString(int type) const {
+  return static_cast<const StunByteStringAttribute*>(GetAttribute(type));
+}
+
+const StunErrorCodeAttribute* StunMessage::GetErrorCode() const {
+  return static_cast<const StunErrorCodeAttribute*>(
+      GetAttribute(STUN_ATTR_ERROR_CODE));
+}
+
+const StunUInt16ListAttribute* StunMessage::GetUnknownAttributes() const {
+  return static_cast<const StunUInt16ListAttribute*>(
+      GetAttribute(STUN_ATTR_UNKNOWN_ATTRIBUTES));
+}
+
+// Verifies a STUN message has a valid MESSAGE-INTEGRITY attribute, using the
+// procedure outlined in RFC 5389, section 15.4.
+bool StunMessage::ValidateMessageIntegrity(const char* data, size_t size,
+                                           const std::string& password) {
+  // Verifying the size of the message.
+  if ((size % 4) != 0) {
+    return false;
+  }
+
+  // Getting the message length from the STUN header.
+  uint16 msg_length = rtc::GetBE16(&data[2]);
+  if (size != (msg_length + kStunHeaderSize)) {
+    return false;
+  }
+
+  // Finding Message Integrity attribute in stun message.
+  size_t current_pos = kStunHeaderSize;
+  bool has_message_integrity_attr = false;
+  while (current_pos < size) {
+    uint16 attr_type, attr_length;
+    // Getting attribute type and length.
+    attr_type = rtc::GetBE16(&data[current_pos]);
+    attr_length = rtc::GetBE16(&data[current_pos + sizeof(attr_type)]);
+
+    // If M-I, sanity check it, and break out.
+    if (attr_type == STUN_ATTR_MESSAGE_INTEGRITY) {
+      if (attr_length != kStunMessageIntegritySize ||
+          current_pos + attr_length > size) {
+        return false;
+      }
+      has_message_integrity_attr = true;
+      break;
+    }
+
+    // Otherwise, skip to the next attribute.
+    current_pos += sizeof(attr_type) + sizeof(attr_length) + attr_length;
+    if ((attr_length % 4) != 0) {
+      current_pos += (4 - (attr_length % 4));
+    }
+  }
+
+  if (!has_message_integrity_attr) {
+    return false;
+  }
+
+  // Getting length of the message to calculate Message Integrity.
+  size_t mi_pos = current_pos;
+  rtc::scoped_ptr<char[]> temp_data(new char[current_pos]);
+  memcpy(temp_data.get(), data, current_pos);
+  if (size > mi_pos + kStunAttributeHeaderSize + kStunMessageIntegritySize) {
+    // Stun message has other attributes after message integrity.
+    // Adjust the length parameter in stun message to calculate HMAC.
+    size_t extra_offset = size -
+        (mi_pos + kStunAttributeHeaderSize + kStunMessageIntegritySize);
+    size_t new_adjusted_len = size - extra_offset - kStunHeaderSize;
+
+    // Writing new length of the STUN message @ Message Length in temp buffer.
+    //      0                   1                   2                   3
+    //      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+    //     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    //     |0 0|     STUN Message Type     |         Message Length        |
+    //     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    rtc::SetBE16(temp_data.get() + 2,
+                       static_cast<uint16>(new_adjusted_len));
+  }
+
+  char hmac[kStunMessageIntegritySize];
+  size_t ret = rtc::ComputeHmac(rtc::DIGEST_SHA_1,
+                                      password.c_str(), password.size(),
+                                      temp_data.get(), mi_pos,
+                                      hmac, sizeof(hmac));
+  ASSERT(ret == sizeof(hmac));
+  if (ret != sizeof(hmac))
+    return false;
+
+  // Comparing the calculated HMAC with the one present in the message.
+  return memcmp(data + current_pos + kStunAttributeHeaderSize,
+                hmac,
+                sizeof(hmac)) == 0;
+}
+
+bool StunMessage::AddMessageIntegrity(const std::string& password) {
+  return AddMessageIntegrity(password.c_str(), password.size());
+}
+
+bool StunMessage::AddMessageIntegrity(const char* key,
+                                      size_t keylen) {
+  // Add the attribute with a dummy value. Since this is a known attribute, it
+  // can't fail.
+  StunByteStringAttribute* msg_integrity_attr =
+      new StunByteStringAttribute(STUN_ATTR_MESSAGE_INTEGRITY,
+          std::string(kStunMessageIntegritySize, '0'));
+  VERIFY(AddAttribute(msg_integrity_attr));
+
+  // Calculate the HMAC for the message.
+  rtc::ByteBuffer buf;
+  if (!Write(&buf))
+    return false;
+
+  int msg_len_for_hmac = static_cast<int>(
+      buf.Length() - kStunAttributeHeaderSize - msg_integrity_attr->length());
+  char hmac[kStunMessageIntegritySize];
+  size_t ret = rtc::ComputeHmac(rtc::DIGEST_SHA_1,
+                                      key, keylen,
+                                      buf.Data(), msg_len_for_hmac,
+                                      hmac, sizeof(hmac));
+  ASSERT(ret == sizeof(hmac));
+  if (ret != sizeof(hmac)) {
+    LOG(LS_ERROR) << "HMAC computation failed. Message-Integrity "
+                  << "has dummy value.";
+    return false;
+  }
+
+  // Insert correct HMAC into the attribute.
+  msg_integrity_attr->CopyBytes(hmac, sizeof(hmac));
+  return true;
+}
+
+// Verifies a message is in fact a STUN message, by performing the checks
+// outlined in RFC 5389, section 7.3, including the FINGERPRINT check detailed
+// in section 15.5.
+bool StunMessage::ValidateFingerprint(const char* data, size_t size) {
+  // Check the message length.
+  size_t fingerprint_attr_size =
+      kStunAttributeHeaderSize + StunUInt32Attribute::SIZE;
+  if (size % 4 != 0 || size < kStunHeaderSize + fingerprint_attr_size)
+    return false;
+
+  // Skip the rest if the magic cookie isn't present.
+  const char* magic_cookie =
+      data + kStunTransactionIdOffset - kStunMagicCookieLength;
+  if (rtc::GetBE32(magic_cookie) != kStunMagicCookie)
+    return false;
+
+  // Check the fingerprint type and length.
+  const char* fingerprint_attr_data = data + size - fingerprint_attr_size;
+  if (rtc::GetBE16(fingerprint_attr_data) != STUN_ATTR_FINGERPRINT ||
+      rtc::GetBE16(fingerprint_attr_data + sizeof(uint16)) !=
+          StunUInt32Attribute::SIZE)
+    return false;
+
+  // Check the fingerprint value.
+  uint32 fingerprint =
+      rtc::GetBE32(fingerprint_attr_data + kStunAttributeHeaderSize);
+  return ((fingerprint ^ STUN_FINGERPRINT_XOR_VALUE) ==
+      rtc::ComputeCrc32(data, size - fingerprint_attr_size));
+}
+
+bool StunMessage::AddFingerprint() {
+  // Add the attribute with a dummy value. Since this is a known attribute,
+  // it can't fail.
+  StunUInt32Attribute* fingerprint_attr =
+     new StunUInt32Attribute(STUN_ATTR_FINGERPRINT, 0);
+  VERIFY(AddAttribute(fingerprint_attr));
+
+  // Calculate the CRC-32 for the message and insert it.
+  rtc::ByteBuffer buf;
+  if (!Write(&buf))
+    return false;
+
+  int msg_len_for_crc32 = static_cast<int>(
+      buf.Length() - kStunAttributeHeaderSize - fingerprint_attr->length());
+  uint32 c = rtc::ComputeCrc32(buf.Data(), msg_len_for_crc32);
+
+  // Insert the correct CRC-32, XORed with a constant, into the attribute.
+  fingerprint_attr->SetValue(c ^ STUN_FINGERPRINT_XOR_VALUE);
+  return true;
+}
+
+bool StunMessage::Read(ByteBuffer* buf) {
+  if (!buf->ReadUInt16(&type_))
+    return false;
+
+  if (type_ & 0x8000) {
+    // RTP and RTCP set the MSB of first byte, since first two bits are version,
+    // and version is always 2 (10). If set, this is not a STUN packet.
+    return false;
+  }
+
+  if (!buf->ReadUInt16(&length_))
+    return false;
+
+  std::string magic_cookie;
+  if (!buf->ReadString(&magic_cookie, kStunMagicCookieLength))
+    return false;
+
+  std::string transaction_id;
+  if (!buf->ReadString(&transaction_id, kStunTransactionIdLength))
+    return false;
+
+  uint32 magic_cookie_int =
+      *reinterpret_cast<const uint32*>(magic_cookie.data());
+  if (rtc::NetworkToHost32(magic_cookie_int) != kStunMagicCookie) {
+    // If magic cookie is invalid it means that the peer implements
+    // RFC3489 instead of RFC5389.
+    transaction_id.insert(0, magic_cookie);
+  }
+  ASSERT(IsValidTransactionId(transaction_id));
+  transaction_id_ = transaction_id;
+
+  if (length_ != buf->Length())
+    return false;
+
+  attrs_->resize(0);
+
+  size_t rest = buf->Length() - length_;
+  while (buf->Length() > rest) {
+    uint16 attr_type, attr_length;
+    if (!buf->ReadUInt16(&attr_type))
+      return false;
+    if (!buf->ReadUInt16(&attr_length))
+      return false;
+
+    StunAttribute* attr = CreateAttribute(attr_type, attr_length);
+    if (!attr) {
+      // Skip any unknown or malformed attributes.
+      if ((attr_length % 4) != 0) {
+        attr_length += (4 - (attr_length % 4));
+      }
+      if (!buf->Consume(attr_length))
+        return false;
+    } else {
+      if (!attr->Read(buf))
+        return false;
+      attrs_->push_back(attr);
+    }
+  }
+
+  ASSERT(buf->Length() == rest);
+  return true;
+}
+
+bool StunMessage::Write(ByteBuffer* buf) const {
+  buf->WriteUInt16(type_);
+  buf->WriteUInt16(length_);
+  if (!IsLegacy())
+    buf->WriteUInt32(kStunMagicCookie);
+  buf->WriteString(transaction_id_);
+
+  for (size_t i = 0; i < attrs_->size(); ++i) {
+    buf->WriteUInt16((*attrs_)[i]->type());
+    buf->WriteUInt16(static_cast<uint16>((*attrs_)[i]->length()));
+    if (!(*attrs_)[i]->Write(buf))
+      return false;
+  }
+
+  return true;
+}
+
+StunAttributeValueType StunMessage::GetAttributeValueType(int type) const {
+  switch (type) {
+    case STUN_ATTR_MAPPED_ADDRESS:      return STUN_VALUE_ADDRESS;
+    case STUN_ATTR_USERNAME:            return STUN_VALUE_BYTE_STRING;
+    case STUN_ATTR_MESSAGE_INTEGRITY:   return STUN_VALUE_BYTE_STRING;
+    case STUN_ATTR_ERROR_CODE:          return STUN_VALUE_ERROR_CODE;
+    case STUN_ATTR_UNKNOWN_ATTRIBUTES:  return STUN_VALUE_UINT16_LIST;
+    case STUN_ATTR_REALM:               return STUN_VALUE_BYTE_STRING;
+    case STUN_ATTR_NONCE:               return STUN_VALUE_BYTE_STRING;
+    case STUN_ATTR_XOR_MAPPED_ADDRESS:  return STUN_VALUE_XOR_ADDRESS;
+    case STUN_ATTR_SOFTWARE:            return STUN_VALUE_BYTE_STRING;
+    case STUN_ATTR_ALTERNATE_SERVER:    return STUN_VALUE_ADDRESS;
+    case STUN_ATTR_FINGERPRINT:         return STUN_VALUE_UINT32;
+    case STUN_ATTR_RETRANSMIT_COUNT:    return STUN_VALUE_UINT32;
+    default:                            return STUN_VALUE_UNKNOWN;
+  }
+}
+
+StunAttribute* StunMessage::CreateAttribute(int type, size_t length) /*const*/ {
+  StunAttributeValueType value_type = GetAttributeValueType(type);
+  return StunAttribute::Create(value_type, type,
+                               static_cast<uint16>(length), this);
+}
+
+const StunAttribute* StunMessage::GetAttribute(int type) const {
+  for (size_t i = 0; i < attrs_->size(); ++i) {
+    if ((*attrs_)[i]->type() == type)
+      return (*attrs_)[i];
+  }
+  return NULL;
+}
+
+bool StunMessage::IsValidTransactionId(const std::string& transaction_id) {
+  return transaction_id.size() == kStunTransactionIdLength ||
+      transaction_id.size() == kStunLegacyTransactionIdLength;
+}
+
+// StunAttribute
+
+StunAttribute::StunAttribute(uint16 type, uint16 length)
+    : type_(type), length_(length) {
+}
+
+void StunAttribute::ConsumePadding(rtc::ByteBuffer* buf) const {
+  int remainder = length_ % 4;
+  if (remainder > 0) {
+    buf->Consume(4 - remainder);
+  }
+}
+
+void StunAttribute::WritePadding(rtc::ByteBuffer* buf) const {
+  int remainder = length_ % 4;
+  if (remainder > 0) {
+    char zeroes[4] = {0};
+    buf->WriteBytes(zeroes, 4 - remainder);
+  }
+}
+
+StunAttribute* StunAttribute::Create(StunAttributeValueType value_type,
+                                     uint16 type, uint16 length,
+                                     StunMessage* owner) {
+  switch (value_type) {
+    case STUN_VALUE_ADDRESS:
+      return new StunAddressAttribute(type, length);
+    case STUN_VALUE_XOR_ADDRESS:
+      return new StunXorAddressAttribute(type, length, owner);
+    case STUN_VALUE_UINT32:
+      return new StunUInt32Attribute(type);
+    case STUN_VALUE_UINT64:
+      return new StunUInt64Attribute(type);
+    case STUN_VALUE_BYTE_STRING:
+      return new StunByteStringAttribute(type, length);
+    case STUN_VALUE_ERROR_CODE:
+      return new StunErrorCodeAttribute(type, length);
+    case STUN_VALUE_UINT16_LIST:
+      return new StunUInt16ListAttribute(type, length);
+    default:
+      return NULL;
+  }
+}
+
+StunAddressAttribute* StunAttribute::CreateAddress(uint16 type) {
+  return new StunAddressAttribute(type, 0);
+}
+
+StunXorAddressAttribute* StunAttribute::CreateXorAddress(uint16 type) {
+  return new StunXorAddressAttribute(type, 0, NULL);
+}
+
+StunUInt64Attribute* StunAttribute::CreateUInt64(uint16 type) {
+  return new StunUInt64Attribute(type);
+}
+
+StunUInt32Attribute* StunAttribute::CreateUInt32(uint16 type) {
+  return new StunUInt32Attribute(type);
+}
+
+StunByteStringAttribute* StunAttribute::CreateByteString(uint16 type) {
+  return new StunByteStringAttribute(type, 0);
+}
+
+StunErrorCodeAttribute* StunAttribute::CreateErrorCode() {
+  return new StunErrorCodeAttribute(
+      STUN_ATTR_ERROR_CODE, StunErrorCodeAttribute::MIN_SIZE);
+}
+
+StunUInt16ListAttribute* StunAttribute::CreateUnknownAttributes() {
+  return new StunUInt16ListAttribute(STUN_ATTR_UNKNOWN_ATTRIBUTES, 0);
+}
+
+StunAddressAttribute::StunAddressAttribute(uint16 type,
+   const rtc::SocketAddress& addr)
+   : StunAttribute(type, 0) {
+  SetAddress(addr);
+}
+
+StunAddressAttribute::StunAddressAttribute(uint16 type, uint16 length)
+    : StunAttribute(type, length) {
+}
+
+bool StunAddressAttribute::Read(ByteBuffer* buf) {
+  uint8 dummy;
+  if (!buf->ReadUInt8(&dummy))
+    return false;
+
+  uint8 stun_family;
+  if (!buf->ReadUInt8(&stun_family)) {
+    return false;
+  }
+  uint16 port;
+  if (!buf->ReadUInt16(&port))
+    return false;
+  if (stun_family == STUN_ADDRESS_IPV4) {
+    in_addr v4addr;
+    if (length() != SIZE_IP4) {
+      return false;
+    }
+    if (!buf->ReadBytes(reinterpret_cast<char*>(&v4addr), sizeof(v4addr))) {
+      return false;
+    }
+    rtc::IPAddress ipaddr(v4addr);
+    SetAddress(rtc::SocketAddress(ipaddr, port));
+  } else if (stun_family == STUN_ADDRESS_IPV6) {
+    in6_addr v6addr;
+    if (length() != SIZE_IP6) {
+      return false;
+    }
+    if (!buf->ReadBytes(reinterpret_cast<char*>(&v6addr), sizeof(v6addr))) {
+      return false;
+    }
+    rtc::IPAddress ipaddr(v6addr);
+    SetAddress(rtc::SocketAddress(ipaddr, port));
+  } else {
+    return false;
+  }
+  return true;
+}
+
+bool StunAddressAttribute::Write(ByteBuffer* buf) const {
+  StunAddressFamily address_family = family();
+  if (address_family == STUN_ADDRESS_UNDEF) {
+    LOG(LS_ERROR) << "Error writing address attribute: unknown family.";
+    return false;
+  }
+  buf->WriteUInt8(0);
+  buf->WriteUInt8(address_family);
+  buf->WriteUInt16(address_.port());
+  switch (address_.family()) {
+    case AF_INET: {
+      in_addr v4addr = address_.ipaddr().ipv4_address();
+      buf->WriteBytes(reinterpret_cast<char*>(&v4addr), sizeof(v4addr));
+      break;
+    }
+    case AF_INET6: {
+      in6_addr v6addr = address_.ipaddr().ipv6_address();
+      buf->WriteBytes(reinterpret_cast<char*>(&v6addr), sizeof(v6addr));
+      break;
+    }
+  }
+  return true;
+}
+
+StunXorAddressAttribute::StunXorAddressAttribute(uint16 type,
+    const rtc::SocketAddress& addr)
+    : StunAddressAttribute(type, addr), owner_(NULL) {
+}
+
+StunXorAddressAttribute::StunXorAddressAttribute(uint16 type,
+                                                 uint16 length,
+                                                 StunMessage* owner)
+    : StunAddressAttribute(type, length), owner_(owner) {}
+
+rtc::IPAddress StunXorAddressAttribute::GetXoredIP() const {
+  if (owner_) {
+    rtc::IPAddress ip = ipaddr();
+    switch (ip.family()) {
+      case AF_INET: {
+        in_addr v4addr = ip.ipv4_address();
+        v4addr.s_addr =
+            (v4addr.s_addr ^ rtc::HostToNetwork32(kStunMagicCookie));
+        return rtc::IPAddress(v4addr);
+      }
+      case AF_INET6: {
+        in6_addr v6addr = ip.ipv6_address();
+        const std::string& transaction_id = owner_->transaction_id();
+        if (transaction_id.length() == kStunTransactionIdLength) {
+          uint32 transactionid_as_ints[3];
+          memcpy(&transactionid_as_ints[0], transaction_id.c_str(),
+                 transaction_id.length());
+          uint32* ip_as_ints = reinterpret_cast<uint32*>(&v6addr.s6_addr);
+          // Transaction ID is in network byte order, but magic cookie
+          // is stored in host byte order.
+          ip_as_ints[0] =
+              (ip_as_ints[0] ^ rtc::HostToNetwork32(kStunMagicCookie));
+          ip_as_ints[1] = (ip_as_ints[1] ^ transactionid_as_ints[0]);
+          ip_as_ints[2] = (ip_as_ints[2] ^ transactionid_as_ints[1]);
+          ip_as_ints[3] = (ip_as_ints[3] ^ transactionid_as_ints[2]);
+          return rtc::IPAddress(v6addr);
+        }
+        break;
+      }
+    }
+  }
+  // Invalid ip family or transaction ID, or missing owner.
+  // Return an AF_UNSPEC address.
+  return rtc::IPAddress();
+}
+
+bool StunXorAddressAttribute::Read(ByteBuffer* buf) {
+  if (!StunAddressAttribute::Read(buf))
+    return false;
+  uint16 xoredport = port() ^ (kStunMagicCookie >> 16);
+  rtc::IPAddress xored_ip = GetXoredIP();
+  SetAddress(rtc::SocketAddress(xored_ip, xoredport));
+  return true;
+}
+
+bool StunXorAddressAttribute::Write(ByteBuffer* buf) const {
+  StunAddressFamily address_family = family();
+  if (address_family == STUN_ADDRESS_UNDEF) {
+    LOG(LS_ERROR) << "Error writing xor-address attribute: unknown family.";
+    return false;
+  }
+  rtc::IPAddress xored_ip = GetXoredIP();
+  if (xored_ip.family() == AF_UNSPEC) {
+    return false;
+  }
+  buf->WriteUInt8(0);
+  buf->WriteUInt8(family());
+  buf->WriteUInt16(port() ^ (kStunMagicCookie >> 16));
+  switch (xored_ip.family()) {
+    case AF_INET: {
+      in_addr v4addr = xored_ip.ipv4_address();
+      buf->WriteBytes(reinterpret_cast<const char*>(&v4addr), sizeof(v4addr));
+      break;
+    }
+    case AF_INET6: {
+      in6_addr v6addr = xored_ip.ipv6_address();
+      buf->WriteBytes(reinterpret_cast<const char*>(&v6addr), sizeof(v6addr));
+      break;
+    }
+  }
+  return true;
+}
+
+StunUInt32Attribute::StunUInt32Attribute(uint16 type, uint32 value)
+    : StunAttribute(type, SIZE), bits_(value) {
+}
+
+StunUInt32Attribute::StunUInt32Attribute(uint16 type)
+    : StunAttribute(type, SIZE), bits_(0) {
+}
+
+bool StunUInt32Attribute::GetBit(size_t index) const {
+  ASSERT(index < 32);
+  return static_cast<bool>((bits_ >> index) & 0x1);
+}
+
+void StunUInt32Attribute::SetBit(size_t index, bool value) {
+  ASSERT(index < 32);
+  bits_ &= ~(1 << index);
+  bits_ |= value ? (1 << index) : 0;
+}
+
+bool StunUInt32Attribute::Read(ByteBuffer* buf) {
+  if (length() != SIZE || !buf->ReadUInt32(&bits_))
+    return false;
+  return true;
+}
+
+bool StunUInt32Attribute::Write(ByteBuffer* buf) const {
+  buf->WriteUInt32(bits_);
+  return true;
+}
+
+StunUInt64Attribute::StunUInt64Attribute(uint16 type, uint64 value)
+    : StunAttribute(type, SIZE), bits_(value) {
+}
+
+StunUInt64Attribute::StunUInt64Attribute(uint16 type)
+    : StunAttribute(type, SIZE), bits_(0) {
+}
+
+bool StunUInt64Attribute::Read(ByteBuffer* buf) {
+  if (length() != SIZE || !buf->ReadUInt64(&bits_))
+    return false;
+  return true;
+}
+
+bool StunUInt64Attribute::Write(ByteBuffer* buf) const {
+  buf->WriteUInt64(bits_);
+  return true;
+}
+
+StunByteStringAttribute::StunByteStringAttribute(uint16 type)
+    : StunAttribute(type, 0), bytes_(NULL) {
+}
+
+StunByteStringAttribute::StunByteStringAttribute(uint16 type,
+                                                 const std::string& str)
+    : StunAttribute(type, 0), bytes_(NULL) {
+  CopyBytes(str.c_str(), str.size());
+}
+
+StunByteStringAttribute::StunByteStringAttribute(uint16 type,
+                                                 const void* bytes,
+                                                 size_t length)
+    : StunAttribute(type, 0), bytes_(NULL) {
+  CopyBytes(bytes, length);
+}
+
+StunByteStringAttribute::StunByteStringAttribute(uint16 type, uint16 length)
+    : StunAttribute(type, length), bytes_(NULL) {
+}
+
+StunByteStringAttribute::~StunByteStringAttribute() {
+  delete [] bytes_;
+}
+
+void StunByteStringAttribute::CopyBytes(const char* bytes) {
+  CopyBytes(bytes, strlen(bytes));
+}
+
+void StunByteStringAttribute::CopyBytes(const void* bytes, size_t length) {
+  char* new_bytes = new char[length];
+  memcpy(new_bytes, bytes, length);
+  SetBytes(new_bytes, length);
+}
+
+uint8 StunByteStringAttribute::GetByte(size_t index) const {
+  ASSERT(bytes_ != NULL);
+  ASSERT(index < length());
+  return static_cast<uint8>(bytes_[index]);
+}
+
+void StunByteStringAttribute::SetByte(size_t index, uint8 value) {
+  ASSERT(bytes_ != NULL);
+  ASSERT(index < length());
+  bytes_[index] = value;
+}
+
+bool StunByteStringAttribute::Read(ByteBuffer* buf) {
+  bytes_ = new char[length()];
+  if (!buf->ReadBytes(bytes_, length())) {
+    return false;
+  }
+
+  ConsumePadding(buf);
+  return true;
+}
+
+bool StunByteStringAttribute::Write(ByteBuffer* buf) const {
+  buf->WriteBytes(bytes_, length());
+  WritePadding(buf);
+  return true;
+}
+
+void StunByteStringAttribute::SetBytes(char* bytes, size_t length) {
+  delete [] bytes_;
+  bytes_ = bytes;
+  SetLength(static_cast<uint16>(length));
+}
+
+StunErrorCodeAttribute::StunErrorCodeAttribute(uint16 type, int code,
+                                               const std::string& reason)
+    : StunAttribute(type, 0) {
+  SetCode(code);
+  SetReason(reason);
+}
+
+StunErrorCodeAttribute::StunErrorCodeAttribute(uint16 type, uint16 length)
+    : StunAttribute(type, length), class_(0), number_(0) {
+}
+
+StunErrorCodeAttribute::~StunErrorCodeAttribute() {
+}
+
+int StunErrorCodeAttribute::code() const {
+  return class_ * 100 + number_;
+}
+
+void StunErrorCodeAttribute::SetCode(int code) {
+  class_ = static_cast<uint8>(code / 100);
+  number_ = static_cast<uint8>(code % 100);
+}
+
+void StunErrorCodeAttribute::SetReason(const std::string& reason) {
+  SetLength(MIN_SIZE + static_cast<uint16>(reason.size()));
+  reason_ = reason;
+}
+
+bool StunErrorCodeAttribute::Read(ByteBuffer* buf) {
+  uint32 val;
+  if (length() < MIN_SIZE || !buf->ReadUInt32(&val))
+    return false;
+
+  if ((val >> 11) != 0)
+    LOG(LS_ERROR) << "error-code bits not zero";
+
+  class_ = ((val >> 8) & 0x7);
+  number_ = (val & 0xff);
+
+  if (!buf->ReadString(&reason_, length() - 4))
+    return false;
+
+  ConsumePadding(buf);
+  return true;
+}
+
+bool StunErrorCodeAttribute::Write(ByteBuffer* buf) const {
+  buf->WriteUInt32(class_ << 8 | number_);
+  buf->WriteString(reason_);
+  WritePadding(buf);
+  return true;
+}
+
+StunUInt16ListAttribute::StunUInt16ListAttribute(uint16 type, uint16 length)
+    : StunAttribute(type, length) {
+  attr_types_ = new std::vector<uint16>();
+}
+
+StunUInt16ListAttribute::~StunUInt16ListAttribute() {
+  delete attr_types_;
+}
+
+size_t StunUInt16ListAttribute::Size() const {
+  return attr_types_->size();
+}
+
+uint16 StunUInt16ListAttribute::GetType(int index) const {
+  return (*attr_types_)[index];
+}
+
+void StunUInt16ListAttribute::SetType(int index, uint16 value) {
+  (*attr_types_)[index] = value;
+}
+
+void StunUInt16ListAttribute::AddType(uint16 value) {
+  attr_types_->push_back(value);
+  SetLength(static_cast<uint16>(attr_types_->size() * 2));
+}
+
+bool StunUInt16ListAttribute::Read(ByteBuffer* buf) {
+  if (length() % 2)
+    return false;
+
+  for (size_t i = 0; i < length() / 2; i++) {
+    uint16 attr;
+    if (!buf->ReadUInt16(&attr))
+      return false;
+    attr_types_->push_back(attr);
+  }
+  // Padding of these attributes is done in RFC 5389 style. This is
+  // slightly different from RFC3489, but it shouldn't be important.
+  // RFC3489 pads out to a 32 bit boundary by duplicating one of the
+  // entries in the list (not necessarily the last one - it's unspecified).
+  // RFC5389 pads on the end, and the bytes are always ignored.
+  ConsumePadding(buf);
+  return true;
+}
+
+bool StunUInt16ListAttribute::Write(ByteBuffer* buf) const {
+  for (size_t i = 0; i < attr_types_->size(); ++i) {
+    buf->WriteUInt16((*attr_types_)[i]);
+  }
+  WritePadding(buf);
+  return true;
+}
+
+int GetStunSuccessResponseType(int req_type) {
+  return IsStunRequestType(req_type) ? (req_type | 0x100) : -1;
+}
+
+int GetStunErrorResponseType(int req_type) {
+  return IsStunRequestType(req_type) ? (req_type | 0x110) : -1;
+}
+
+bool IsStunRequestType(int msg_type) {
+  return ((msg_type & kStunTypeMask) == 0x000);
+}
+
+bool IsStunIndicationType(int msg_type) {
+  return ((msg_type & kStunTypeMask) == 0x010);
+}
+
+bool IsStunSuccessResponseType(int msg_type) {
+  return ((msg_type & kStunTypeMask) == 0x100);
+}
+
+bool IsStunErrorResponseType(int msg_type) {
+  return ((msg_type & kStunTypeMask) == 0x110);
+}
+
+bool ComputeStunCredentialHash(const std::string& username,
+                               const std::string& realm,
+                               const std::string& password,
+                               std::string* hash) {
+  // http://tools.ietf.org/html/rfc5389#section-15.4
+  // long-term credentials will be calculated using the key and key is
+  // key = MD5(username ":" realm ":" SASLprep(password))
+  std::string input = username;
+  input += ':';
+  input += realm;
+  input += ':';
+  input += password;
+
+  char digest[rtc::MessageDigest::kMaxSize];
+  size_t size = rtc::ComputeDigest(
+      rtc::DIGEST_MD5, input.c_str(), input.size(),
+      digest, sizeof(digest));
+  if (size == 0) {
+    return false;
+  }
+
+  *hash = std::string(digest, size);
+  return true;
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/stun.h b/webrtc/p2p/base/stun.h
new file mode 100644
index 0000000..0f600db
--- /dev/null
+++ b/webrtc/p2p/base/stun.h
@@ -0,0 +1,632 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_STUN_H_
+#define WEBRTC_P2P_BASE_STUN_H_
+
+// This file contains classes for dealing with the STUN protocol, as specified
+// in RFC 5389, and its descendants.
+
+#include <string>
+#include <vector>
+
+#include "webrtc/base/basictypes.h"
+#include "webrtc/base/bytebuffer.h"
+#include "webrtc/base/socketaddress.h"
+
+namespace cricket {
+
+// These are the types of STUN messages defined in RFC 5389.
+enum StunMessageType {
+  STUN_BINDING_REQUEST                  = 0x0001,
+  STUN_BINDING_INDICATION               = 0x0011,
+  STUN_BINDING_RESPONSE                 = 0x0101,
+  STUN_BINDING_ERROR_RESPONSE           = 0x0111,
+};
+
+// These are all known STUN attributes, defined in RFC 5389 and elsewhere.
+// Next to each is the name of the class (T is StunTAttribute) that implements
+// that type.
+// RETRANSMIT_COUNT is the number of outstanding pings without a response at
+// the time the packet is generated.
+enum StunAttributeType {
+  STUN_ATTR_MAPPED_ADDRESS              = 0x0001,  // Address
+  STUN_ATTR_USERNAME                    = 0x0006,  // ByteString
+  STUN_ATTR_MESSAGE_INTEGRITY           = 0x0008,  // ByteString, 20 bytes
+  STUN_ATTR_ERROR_CODE                  = 0x0009,  // ErrorCode
+  STUN_ATTR_UNKNOWN_ATTRIBUTES          = 0x000a,  // UInt16List
+  STUN_ATTR_REALM                       = 0x0014,  // ByteString
+  STUN_ATTR_NONCE                       = 0x0015,  // ByteString
+  STUN_ATTR_XOR_MAPPED_ADDRESS          = 0x0020,  // XorAddress
+  STUN_ATTR_SOFTWARE                    = 0x8022,  // ByteString
+  STUN_ATTR_ALTERNATE_SERVER            = 0x8023,  // Address
+  STUN_ATTR_FINGERPRINT                 = 0x8028,  // UInt32
+  STUN_ATTR_RETRANSMIT_COUNT            = 0xFF00   // UInt32
+};
+
+// These are the types of the values associated with the attributes above.
+// This allows us to perform some basic validation when reading or adding
+// attributes. Note that these values are for our own use, and not defined in
+// RFC 5389.
+enum StunAttributeValueType {
+  STUN_VALUE_UNKNOWN                    = 0,
+  STUN_VALUE_ADDRESS                    = 1,
+  STUN_VALUE_XOR_ADDRESS                = 2,
+  STUN_VALUE_UINT32                     = 3,
+  STUN_VALUE_UINT64                     = 4,
+  STUN_VALUE_BYTE_STRING                = 5,
+  STUN_VALUE_ERROR_CODE                 = 6,
+  STUN_VALUE_UINT16_LIST                = 7
+};
+
+// These are the types of STUN addresses defined in RFC 5389.
+enum StunAddressFamily {
+  // NB: UNDEF is not part of the STUN spec.
+  STUN_ADDRESS_UNDEF                    = 0,
+  STUN_ADDRESS_IPV4                     = 1,
+  STUN_ADDRESS_IPV6                     = 2
+};
+
+// These are the types of STUN error codes defined in RFC 5389.
+enum StunErrorCode {
+  STUN_ERROR_TRY_ALTERNATE              = 300,
+  STUN_ERROR_BAD_REQUEST                = 400,
+  STUN_ERROR_UNAUTHORIZED               = 401,
+  STUN_ERROR_UNKNOWN_ATTRIBUTE          = 420,
+  STUN_ERROR_STALE_CREDENTIALS          = 430,  // GICE only
+  STUN_ERROR_STALE_NONCE                = 438,
+  STUN_ERROR_SERVER_ERROR               = 500,
+  STUN_ERROR_GLOBAL_FAILURE             = 600
+};
+
+// Strings for the error codes above.
+extern const char STUN_ERROR_REASON_TRY_ALTERNATE_SERVER[];
+extern const char STUN_ERROR_REASON_BAD_REQUEST[];
+extern const char STUN_ERROR_REASON_UNAUTHORIZED[];
+extern const char STUN_ERROR_REASON_UNKNOWN_ATTRIBUTE[];
+extern const char STUN_ERROR_REASON_STALE_CREDENTIALS[];
+extern const char STUN_ERROR_REASON_STALE_NONCE[];
+extern const char STUN_ERROR_REASON_SERVER_ERROR[];
+
+// The mask used to determine whether a STUN message is a request/response etc.
+const uint32 kStunTypeMask = 0x0110;
+
+// STUN Attribute header length.
+const size_t kStunAttributeHeaderSize = 4;
+
+// Following values correspond to RFC5389.
+const size_t kStunHeaderSize = 20;
+const size_t kStunTransactionIdOffset = 8;
+const size_t kStunTransactionIdLength = 12;
+const uint32 kStunMagicCookie = 0x2112A442;
+const size_t kStunMagicCookieLength = sizeof(kStunMagicCookie);
+
+// Following value corresponds to an earlier version of STUN from
+// RFC3489.
+const size_t kStunLegacyTransactionIdLength = 16;
+
+// STUN Message Integrity HMAC length.
+const size_t kStunMessageIntegritySize = 20;
+
+class StunAttribute;
+class StunAddressAttribute;
+class StunXorAddressAttribute;
+class StunUInt32Attribute;
+class StunUInt64Attribute;
+class StunByteStringAttribute;
+class StunErrorCodeAttribute;
+class StunUInt16ListAttribute;
+
+// Records a complete STUN/TURN message.  Each message consists of a type and
+// any number of attributes.  Each attribute is parsed into an instance of an
+// appropriate class (see above).  The Get* methods will return instances of
+// that attribute class.
+class StunMessage {
+ public:
+  StunMessage();
+  virtual ~StunMessage();
+
+  int type() const { return type_; }
+  size_t length() const { return length_; }
+  const std::string& transaction_id() const { return transaction_id_; }
+
+  // Returns true if the message confirms to RFC3489 rather than
+  // RFC5389. The main difference between two version of the STUN
+  // protocol is the presence of the magic cookie and different length
+  // of transaction ID. For outgoing packets version of the protocol
+  // is determined by the lengths of the transaction ID.
+  bool IsLegacy() const;
+
+  void SetType(int type) { type_ = static_cast<uint16>(type); }
+  bool SetTransactionID(const std::string& str);
+
+  // Gets the desired attribute value, or NULL if no such attribute type exists.
+  const StunAddressAttribute* GetAddress(int type) const;
+  const StunUInt32Attribute* GetUInt32(int type) const;
+  const StunUInt64Attribute* GetUInt64(int type) const;
+  const StunByteStringAttribute* GetByteString(int type) const;
+
+  // Gets these specific attribute values.
+  const StunErrorCodeAttribute* GetErrorCode() const;
+  const StunUInt16ListAttribute* GetUnknownAttributes() const;
+
+  // Takes ownership of the specified attribute, verifies it is of the correct
+  // type, and adds it to the message. The return value indicates whether this
+  // was successful.
+  bool AddAttribute(StunAttribute* attr);
+
+  // Validates that a raw STUN message has a correct MESSAGE-INTEGRITY value.
+  // This can't currently be done on a StunMessage, since it is affected by
+  // padding data (which we discard when reading a StunMessage).
+  static bool ValidateMessageIntegrity(const char* data, size_t size,
+                                       const std::string& password);
+  // Adds a MESSAGE-INTEGRITY attribute that is valid for the current message.
+  bool AddMessageIntegrity(const std::string& password);
+  bool AddMessageIntegrity(const char* key, size_t keylen);
+
+  // Verifies that a given buffer is STUN by checking for a correct FINGERPRINT.
+  static bool ValidateFingerprint(const char* data, size_t size);
+
+  // Adds a FINGERPRINT attribute that is valid for the current message.
+  bool AddFingerprint();
+
+  // Parses the STUN packet in the given buffer and records it here. The
+  // return value indicates whether this was successful.
+  bool Read(rtc::ByteBuffer* buf);
+
+  // Writes this object into a STUN packet. The return value indicates whether
+  // this was successful.
+  bool Write(rtc::ByteBuffer* buf) const;
+
+  // Creates an empty message. Overridable by derived classes.
+  virtual StunMessage* CreateNew() const { return new StunMessage(); }
+
+ protected:
+  // Verifies that the given attribute is allowed for this message.
+  virtual StunAttributeValueType GetAttributeValueType(int type) const;
+
+ private:
+  StunAttribute* CreateAttribute(int type, size_t length) /* const*/;
+  const StunAttribute* GetAttribute(int type) const;
+  static bool IsValidTransactionId(const std::string& transaction_id);
+
+  uint16 type_;
+  uint16 length_;
+  std::string transaction_id_;
+  std::vector<StunAttribute*>* attrs_;
+};
+
+// Base class for all STUN/TURN attributes.
+class StunAttribute {
+ public:
+  virtual ~StunAttribute() {
+  }
+
+  int type() const { return type_; }
+  size_t length() const { return length_; }
+
+  // Return the type of this attribute.
+  virtual StunAttributeValueType value_type() const = 0;
+
+  // Only XorAddressAttribute needs this so far.
+  virtual void SetOwner(StunMessage* owner) {}
+
+  // Reads the body (not the type or length) for this type of attribute from
+  // the given buffer.  Return value is true if successful.
+  virtual bool Read(rtc::ByteBuffer* buf) = 0;
+
+  // Writes the body (not the type or length) to the given buffer.  Return
+  // value is true if successful.
+  virtual bool Write(rtc::ByteBuffer* buf) const = 0;
+
+  // Creates an attribute object with the given type and smallest length.
+  static StunAttribute* Create(StunAttributeValueType value_type, uint16 type,
+                               uint16 length, StunMessage* owner);
+  // TODO: Allow these create functions to take parameters, to reduce
+  // the amount of work callers need to do to initialize attributes.
+  static StunAddressAttribute* CreateAddress(uint16 type);
+  static StunXorAddressAttribute* CreateXorAddress(uint16 type);
+  static StunUInt32Attribute* CreateUInt32(uint16 type);
+  static StunUInt64Attribute* CreateUInt64(uint16 type);
+  static StunByteStringAttribute* CreateByteString(uint16 type);
+  static StunErrorCodeAttribute* CreateErrorCode();
+  static StunUInt16ListAttribute* CreateUnknownAttributes();
+
+ protected:
+  StunAttribute(uint16 type, uint16 length);
+  void SetLength(uint16 length) { length_ = length; }
+  void WritePadding(rtc::ByteBuffer* buf) const;
+  void ConsumePadding(rtc::ByteBuffer* buf) const;
+
+ private:
+  uint16 type_;
+  uint16 length_;
+};
+
+// Implements STUN attributes that record an Internet address.
+class StunAddressAttribute : public StunAttribute {
+ public:
+  static const uint16 SIZE_UNDEF = 0;
+  static const uint16 SIZE_IP4 = 8;
+  static const uint16 SIZE_IP6 = 20;
+  StunAddressAttribute(uint16 type, const rtc::SocketAddress& addr);
+  StunAddressAttribute(uint16 type, uint16 length);
+
+  virtual StunAttributeValueType value_type() const {
+    return STUN_VALUE_ADDRESS;
+  }
+
+  StunAddressFamily family() const {
+    switch (address_.ipaddr().family()) {
+      case AF_INET:
+        return STUN_ADDRESS_IPV4;
+      case AF_INET6:
+        return STUN_ADDRESS_IPV6;
+    }
+    return STUN_ADDRESS_UNDEF;
+  }
+
+  const rtc::SocketAddress& GetAddress() const { return address_; }
+  const rtc::IPAddress& ipaddr() const { return address_.ipaddr(); }
+  uint16 port() const { return address_.port(); }
+
+  void SetAddress(const rtc::SocketAddress& addr) {
+    address_ = addr;
+    EnsureAddressLength();
+  }
+  void SetIP(const rtc::IPAddress& ip) {
+    address_.SetIP(ip);
+    EnsureAddressLength();
+  }
+  void SetPort(uint16 port) { address_.SetPort(port); }
+
+  virtual bool Read(rtc::ByteBuffer* buf);
+  virtual bool Write(rtc::ByteBuffer* buf) const;
+
+ private:
+  void EnsureAddressLength() {
+    switch (family()) {
+      case STUN_ADDRESS_IPV4: {
+        SetLength(SIZE_IP4);
+        break;
+      }
+      case STUN_ADDRESS_IPV6: {
+        SetLength(SIZE_IP6);
+        break;
+      }
+      default: {
+        SetLength(SIZE_UNDEF);
+        break;
+      }
+    }
+  }
+  rtc::SocketAddress address_;
+};
+
+// Implements STUN attributes that record an Internet address. When encoded
+// in a STUN message, the address contained in this attribute is XORed with the
+// transaction ID of the message.
+class StunXorAddressAttribute : public StunAddressAttribute {
+ public:
+  StunXorAddressAttribute(uint16 type, const rtc::SocketAddress& addr);
+  StunXorAddressAttribute(uint16 type, uint16 length,
+                          StunMessage* owner);
+
+  virtual StunAttributeValueType value_type() const {
+    return STUN_VALUE_XOR_ADDRESS;
+  }
+  virtual void SetOwner(StunMessage* owner) {
+    owner_ = owner;
+  }
+  virtual bool Read(rtc::ByteBuffer* buf);
+  virtual bool Write(rtc::ByteBuffer* buf) const;
+
+ private:
+  rtc::IPAddress GetXoredIP() const;
+  StunMessage* owner_;
+};
+
+// Implements STUN attributes that record a 32-bit integer.
+class StunUInt32Attribute : public StunAttribute {
+ public:
+  static const uint16 SIZE = 4;
+  StunUInt32Attribute(uint16 type, uint32 value);
+  explicit StunUInt32Attribute(uint16 type);
+
+  virtual StunAttributeValueType value_type() const {
+    return STUN_VALUE_UINT32;
+  }
+
+  uint32 value() const { return bits_; }
+  void SetValue(uint32 bits) { bits_ = bits; }
+
+  bool GetBit(size_t index) const;
+  void SetBit(size_t index, bool value);
+
+  virtual bool Read(rtc::ByteBuffer* buf);
+  virtual bool Write(rtc::ByteBuffer* buf) const;
+
+ private:
+  uint32 bits_;
+};
+
+class StunUInt64Attribute : public StunAttribute {
+ public:
+  static const uint16 SIZE = 8;
+  StunUInt64Attribute(uint16 type, uint64 value);
+  explicit StunUInt64Attribute(uint16 type);
+
+  virtual StunAttributeValueType value_type() const {
+    return STUN_VALUE_UINT64;
+  }
+
+  uint64 value() const { return bits_; }
+  void SetValue(uint64 bits) { bits_ = bits; }
+
+  virtual bool Read(rtc::ByteBuffer* buf);
+  virtual bool Write(rtc::ByteBuffer* buf) const;
+
+ private:
+  uint64 bits_;
+};
+
+// Implements STUN attributes that record an arbitrary byte string.
+class StunByteStringAttribute : public StunAttribute {
+ public:
+  explicit StunByteStringAttribute(uint16 type);
+  StunByteStringAttribute(uint16 type, const std::string& str);
+  StunByteStringAttribute(uint16 type, const void* bytes, size_t length);
+  StunByteStringAttribute(uint16 type, uint16 length);
+  ~StunByteStringAttribute();
+
+  virtual StunAttributeValueType value_type() const {
+    return STUN_VALUE_BYTE_STRING;
+  }
+
+  const char* bytes() const { return bytes_; }
+  std::string GetString() const { return std::string(bytes_, length()); }
+
+  void CopyBytes(const char* bytes);  // uses strlen
+  void CopyBytes(const void* bytes, size_t length);
+
+  uint8 GetByte(size_t index) const;
+  void SetByte(size_t index, uint8 value);
+
+  virtual bool Read(rtc::ByteBuffer* buf);
+  virtual bool Write(rtc::ByteBuffer* buf) const;
+
+ private:
+  void SetBytes(char* bytes, size_t length);
+
+  char* bytes_;
+};
+
+// Implements STUN attributes that record an error code.
+class StunErrorCodeAttribute : public StunAttribute {
+ public:
+  static const uint16 MIN_SIZE = 4;
+  StunErrorCodeAttribute(uint16 type, int code, const std::string& reason);
+  StunErrorCodeAttribute(uint16 type, uint16 length);
+  ~StunErrorCodeAttribute();
+
+  virtual StunAttributeValueType value_type() const {
+    return STUN_VALUE_ERROR_CODE;
+  }
+
+  // The combined error and class, e.g. 0x400.
+  int code() const;
+  void SetCode(int code);
+
+  // The individual error components.
+  int eclass() const { return class_; }
+  int number() const { return number_; }
+  const std::string& reason() const { return reason_; }
+  void SetClass(uint8 eclass) { class_ = eclass; }
+  void SetNumber(uint8 number) { number_ = number; }
+  void SetReason(const std::string& reason);
+
+  bool Read(rtc::ByteBuffer* buf);
+  bool Write(rtc::ByteBuffer* buf) const;
+
+ private:
+  uint8 class_;
+  uint8 number_;
+  std::string reason_;
+};
+
+// Implements STUN attributes that record a list of attribute names.
+class StunUInt16ListAttribute : public StunAttribute {
+ public:
+  StunUInt16ListAttribute(uint16 type, uint16 length);
+  ~StunUInt16ListAttribute();
+
+  virtual StunAttributeValueType value_type() const {
+    return STUN_VALUE_UINT16_LIST;
+  }
+
+  size_t Size() const;
+  uint16 GetType(int index) const;
+  void SetType(int index, uint16 value);
+  void AddType(uint16 value);
+
+  bool Read(rtc::ByteBuffer* buf);
+  bool Write(rtc::ByteBuffer* buf) const;
+
+ private:
+  std::vector<uint16>* attr_types_;
+};
+
+// Returns the (successful) response type for the given request type.
+// Returns -1 if |request_type| is not a valid request type.
+int GetStunSuccessResponseType(int request_type);
+
+// Returns the error response type for the given request type.
+// Returns -1 if |request_type| is not a valid request type.
+int GetStunErrorResponseType(int request_type);
+
+// Returns whether a given message is a request type.
+bool IsStunRequestType(int msg_type);
+
+// Returns whether a given message is an indication type.
+bool IsStunIndicationType(int msg_type);
+
+// Returns whether a given response is a success type.
+bool IsStunSuccessResponseType(int msg_type);
+
+// Returns whether a given response is an error type.
+bool IsStunErrorResponseType(int msg_type);
+
+// Computes the STUN long-term credential hash.
+bool ComputeStunCredentialHash(const std::string& username,
+    const std::string& realm, const std::string& password, std::string* hash);
+
+// TODO: Move the TURN/ICE stuff below out to separate files.
+extern const char TURN_MAGIC_COOKIE_VALUE[4];
+
+// "GTURN" STUN methods.
+// TODO: Rename these methods to GTURN_ to make it clear they aren't
+// part of standard STUN/TURN.
+enum RelayMessageType {
+  // For now, using the same defs from TurnMessageType below.
+  // STUN_ALLOCATE_REQUEST              = 0x0003,
+  // STUN_ALLOCATE_RESPONSE             = 0x0103,
+  // STUN_ALLOCATE_ERROR_RESPONSE       = 0x0113,
+  STUN_SEND_REQUEST                     = 0x0004,
+  STUN_SEND_RESPONSE                    = 0x0104,
+  STUN_SEND_ERROR_RESPONSE              = 0x0114,
+  STUN_DATA_INDICATION                  = 0x0115,
+};
+
+// "GTURN"-specific STUN attributes.
+// TODO: Rename these attributes to GTURN_ to avoid conflicts.
+enum RelayAttributeType {
+  STUN_ATTR_LIFETIME                    = 0x000d,  // UInt32
+  STUN_ATTR_MAGIC_COOKIE                = 0x000f,  // ByteString, 4 bytes
+  STUN_ATTR_BANDWIDTH                   = 0x0010,  // UInt32
+  STUN_ATTR_DESTINATION_ADDRESS         = 0x0011,  // Address
+  STUN_ATTR_SOURCE_ADDRESS2             = 0x0012,  // Address
+  STUN_ATTR_DATA                        = 0x0013,  // ByteString
+  STUN_ATTR_OPTIONS                     = 0x8001,  // UInt32
+};
+
+// A "GTURN" STUN message.
+class RelayMessage : public StunMessage {
+ protected:
+  virtual StunAttributeValueType GetAttributeValueType(int type) const {
+    switch (type) {
+      case STUN_ATTR_LIFETIME:            return STUN_VALUE_UINT32;
+      case STUN_ATTR_MAGIC_COOKIE:        return STUN_VALUE_BYTE_STRING;
+      case STUN_ATTR_BANDWIDTH:           return STUN_VALUE_UINT32;
+      case STUN_ATTR_DESTINATION_ADDRESS: return STUN_VALUE_ADDRESS;
+      case STUN_ATTR_SOURCE_ADDRESS2:     return STUN_VALUE_ADDRESS;
+      case STUN_ATTR_DATA:                return STUN_VALUE_BYTE_STRING;
+      case STUN_ATTR_OPTIONS:             return STUN_VALUE_UINT32;
+      default: return StunMessage::GetAttributeValueType(type);
+    }
+  }
+  virtual StunMessage* CreateNew() const { return new RelayMessage(); }
+};
+
+// Defined in TURN RFC 5766.
+enum TurnMessageType {
+  STUN_ALLOCATE_REQUEST                 = 0x0003,
+  STUN_ALLOCATE_RESPONSE                = 0x0103,
+  STUN_ALLOCATE_ERROR_RESPONSE          = 0x0113,
+  TURN_REFRESH_REQUEST                  = 0x0004,
+  TURN_REFRESH_RESPONSE                 = 0x0104,
+  TURN_REFRESH_ERROR_RESPONSE           = 0x0114,
+  TURN_SEND_INDICATION                  = 0x0016,
+  TURN_DATA_INDICATION                  = 0x0017,
+  TURN_CREATE_PERMISSION_REQUEST        = 0x0008,
+  TURN_CREATE_PERMISSION_RESPONSE       = 0x0108,
+  TURN_CREATE_PERMISSION_ERROR_RESPONSE = 0x0118,
+  TURN_CHANNEL_BIND_REQUEST             = 0x0009,
+  TURN_CHANNEL_BIND_RESPONSE            = 0x0109,
+  TURN_CHANNEL_BIND_ERROR_RESPONSE      = 0x0119,
+};
+
+enum TurnAttributeType {
+  STUN_ATTR_CHANNEL_NUMBER              = 0x000C,  // UInt32
+  STUN_ATTR_TURN_LIFETIME               = 0x000d,  // UInt32
+  STUN_ATTR_XOR_PEER_ADDRESS            = 0x0012,  // XorAddress
+  // TODO(mallinath) - Uncomment after RelayAttributes are renamed.
+  // STUN_ATTR_DATA                     = 0x0013,  // ByteString
+  STUN_ATTR_XOR_RELAYED_ADDRESS         = 0x0016,  // XorAddress
+  STUN_ATTR_EVEN_PORT                   = 0x0018,  // ByteString, 1 byte.
+  STUN_ATTR_REQUESTED_TRANSPORT         = 0x0019,  // UInt32
+  STUN_ATTR_DONT_FRAGMENT               = 0x001A,  // No content, Length = 0
+  STUN_ATTR_RESERVATION_TOKEN           = 0x0022,  // ByteString, 8 bytes.
+  // TODO(mallinath) - Rename STUN_ATTR_TURN_LIFETIME to STUN_ATTR_LIFETIME and
+  // STUN_ATTR_TURN_DATA to STUN_ATTR_DATA. Also rename RelayMessage attributes
+  // by appending G to attribute name.
+};
+
+// RFC 5766-defined errors.
+enum TurnErrorType {
+  STUN_ERROR_FORBIDDEN                  = 403,
+  STUN_ERROR_ALLOCATION_MISMATCH        = 437,
+  STUN_ERROR_WRONG_CREDENTIALS          = 441,
+  STUN_ERROR_UNSUPPORTED_PROTOCOL       = 442
+};
+extern const char STUN_ERROR_REASON_FORBIDDEN[];
+extern const char STUN_ERROR_REASON_ALLOCATION_MISMATCH[];
+extern const char STUN_ERROR_REASON_WRONG_CREDENTIALS[];
+extern const char STUN_ERROR_REASON_UNSUPPORTED_PROTOCOL[];
+class TurnMessage : public StunMessage {
+ protected:
+  virtual StunAttributeValueType GetAttributeValueType(int type) const {
+    switch (type) {
+      case STUN_ATTR_CHANNEL_NUMBER:      return STUN_VALUE_UINT32;
+      case STUN_ATTR_TURN_LIFETIME:       return STUN_VALUE_UINT32;
+      case STUN_ATTR_XOR_PEER_ADDRESS:    return STUN_VALUE_XOR_ADDRESS;
+      case STUN_ATTR_DATA:                return STUN_VALUE_BYTE_STRING;
+      case STUN_ATTR_XOR_RELAYED_ADDRESS: return STUN_VALUE_XOR_ADDRESS;
+      case STUN_ATTR_EVEN_PORT:           return STUN_VALUE_BYTE_STRING;
+      case STUN_ATTR_REQUESTED_TRANSPORT: return STUN_VALUE_UINT32;
+      case STUN_ATTR_DONT_FRAGMENT:       return STUN_VALUE_BYTE_STRING;
+      case STUN_ATTR_RESERVATION_TOKEN:   return STUN_VALUE_BYTE_STRING;
+      default: return StunMessage::GetAttributeValueType(type);
+    }
+  }
+  virtual StunMessage* CreateNew() const { return new TurnMessage(); }
+};
+
+// RFC 5245 ICE STUN attributes.
+enum IceAttributeType {
+  STUN_ATTR_PRIORITY                    = 0x0024,  // UInt32
+  STUN_ATTR_USE_CANDIDATE               = 0x0025,  // No content, Length = 0
+  STUN_ATTR_ICE_CONTROLLED              = 0x8029,  // UInt64
+  STUN_ATTR_ICE_CONTROLLING             = 0x802A   // UInt64
+};
+
+// RFC 5245-defined errors.
+enum IceErrorCode {
+  STUN_ERROR_ROLE_CONFLICT              = 487,
+};
+extern const char STUN_ERROR_REASON_ROLE_CONFLICT[];
+
+// A RFC 5245 ICE STUN message.
+class IceMessage : public StunMessage {
+ protected:
+  virtual StunAttributeValueType GetAttributeValueType(int type) const {
+    switch (type) {
+      case STUN_ATTR_PRIORITY:        return STUN_VALUE_UINT32;
+      case STUN_ATTR_USE_CANDIDATE:   return STUN_VALUE_BYTE_STRING;
+      case STUN_ATTR_ICE_CONTROLLED:  return STUN_VALUE_UINT64;
+      case STUN_ATTR_ICE_CONTROLLING: return STUN_VALUE_UINT64;
+      default: return StunMessage::GetAttributeValueType(type);
+    }
+  }
+  virtual StunMessage* CreateNew() const { return new IceMessage(); }
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_STUN_H_
diff --git a/webrtc/p2p/base/stun_unittest.cc b/webrtc/p2p/base/stun_unittest.cc
new file mode 100644
index 0000000..396beb6
--- /dev/null
+++ b/webrtc/p2p/base/stun_unittest.cc
@@ -0,0 +1,1402 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <string>
+
+#include "webrtc/p2p/base/stun.h"
+#include "webrtc/base/bytebuffer.h"
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/messagedigest.h"
+#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/socketaddress.h"
+
+namespace cricket {
+
+class StunTest : public ::testing::Test {
+ protected:
+  void CheckStunHeader(const StunMessage& msg, StunMessageType expected_type,
+                       size_t expected_length) {
+    ASSERT_EQ(expected_type, msg.type());
+    ASSERT_EQ(expected_length, msg.length());
+  }
+
+  void CheckStunTransactionID(const StunMessage& msg,
+                              const unsigned char* expectedID, size_t length) {
+    ASSERT_EQ(length, msg.transaction_id().size());
+    ASSERT_EQ(length == kStunTransactionIdLength + 4, msg.IsLegacy());
+    ASSERT_EQ(length == kStunTransactionIdLength, !msg.IsLegacy());
+    ASSERT_EQ(0, memcmp(msg.transaction_id().c_str(), expectedID, length));
+  }
+
+  void CheckStunAddressAttribute(const StunAddressAttribute* addr,
+                                 StunAddressFamily expected_family,
+                                 int expected_port,
+                                 rtc::IPAddress expected_address) {
+    ASSERT_EQ(expected_family, addr->family());
+    ASSERT_EQ(expected_port, addr->port());
+
+    if (addr->family() == STUN_ADDRESS_IPV4) {
+      in_addr v4_address = expected_address.ipv4_address();
+      in_addr stun_address = addr->ipaddr().ipv4_address();
+      ASSERT_EQ(0, memcmp(&v4_address, &stun_address, sizeof(stun_address)));
+    } else if (addr->family() == STUN_ADDRESS_IPV6) {
+      in6_addr v6_address = expected_address.ipv6_address();
+      in6_addr stun_address = addr->ipaddr().ipv6_address();
+      ASSERT_EQ(0, memcmp(&v6_address, &stun_address, sizeof(stun_address)));
+    } else {
+      ASSERT_TRUE(addr->family() == STUN_ADDRESS_IPV6 ||
+                  addr->family() == STUN_ADDRESS_IPV4);
+    }
+  }
+
+  size_t ReadStunMessageTestCase(StunMessage* msg,
+                                 const unsigned char* testcase,
+                                 size_t size) {
+    const char* input = reinterpret_cast<const char*>(testcase);
+    rtc::ByteBuffer buf(input, size);
+    if (msg->Read(&buf)) {
+      // Returns the size the stun message should report itself as being
+      return (size - 20);
+    } else {
+      return 0;
+    }
+  }
+};
+
+
+// Sample STUN packets with various attributes
+// Gathered by wiresharking pjproject's pjnath test programs
+// pjproject available at www.pjsip.org
+
+static const unsigned char kStunMessageWithIPv6MappedAddress[] = {
+  0x00, 0x01, 0x00, 0x18,  // message header
+  0x21, 0x12, 0xa4, 0x42,  // transaction id
+  0x29, 0x1f, 0xcd, 0x7c,
+  0xba, 0x58, 0xab, 0xd7,
+  0xf2, 0x41, 0x01, 0x00,
+  0x00, 0x01, 0x00, 0x14,  // Address type (mapped), length
+  0x00, 0x02, 0xb8, 0x81,  // family (IPv6), port
+  0x24, 0x01, 0xfa, 0x00,  // an IPv6 address
+  0x00, 0x04, 0x10, 0x00,
+  0xbe, 0x30, 0x5b, 0xff,
+  0xfe, 0xe5, 0x00, 0xc3
+};
+
+static const unsigned char kStunMessageWithIPv4MappedAddress[] = {
+  0x01, 0x01, 0x00, 0x0c,   // binding response, length 12
+  0x21, 0x12, 0xa4, 0x42,   // magic cookie
+  0x29, 0x1f, 0xcd, 0x7c,   // transaction ID
+  0xba, 0x58, 0xab, 0xd7,
+  0xf2, 0x41, 0x01, 0x00,
+  0x00, 0x01, 0x00, 0x08,  // Mapped, 8 byte length
+  0x00, 0x01, 0x9d, 0xfc,  // AF_INET, unxor-ed port
+  0xac, 0x17, 0x44, 0xe6   // IPv4 address
+};
+
+// Test XOR-mapped IP addresses:
+static const unsigned char kStunMessageWithIPv6XorMappedAddress[] = {
+  0x01, 0x01, 0x00, 0x18,  // message header (binding response)
+  0x21, 0x12, 0xa4, 0x42,  // magic cookie (rfc5389)
+  0xe3, 0xa9, 0x46, 0xe1,  // transaction ID
+  0x7c, 0x00, 0xc2, 0x62,
+  0x54, 0x08, 0x01, 0x00,
+  0x00, 0x20, 0x00, 0x14,  // Address Type (XOR), length
+  0x00, 0x02, 0xcb, 0x5b,  // family, XOR-ed port
+  0x05, 0x13, 0x5e, 0x42,  // XOR-ed IPv6 address
+  0xe3, 0xad, 0x56, 0xe1,
+  0xc2, 0x30, 0x99, 0x9d,
+  0xaa, 0xed, 0x01, 0xc3
+};
+
+static const unsigned char kStunMessageWithIPv4XorMappedAddress[] = {
+  0x01, 0x01, 0x00, 0x0c,  // message header (binding response)
+  0x21, 0x12, 0xa4, 0x42,  // magic cookie
+  0x29, 0x1f, 0xcd, 0x7c,  // transaction ID
+  0xba, 0x58, 0xab, 0xd7,
+  0xf2, 0x41, 0x01, 0x00,
+  0x00, 0x20, 0x00, 0x08,  // address type (xor), length
+  0x00, 0x01, 0xfc, 0xb5,  // family (AF_INET), XOR-ed port
+  0x8d, 0x05, 0xe0, 0xa4   // IPv4 address
+};
+
+// ByteString Attribute (username)
+static const unsigned char kStunMessageWithByteStringAttribute[] = {
+  0x00, 0x01, 0x00, 0x0c,
+  0x21, 0x12, 0xa4, 0x42,
+  0xe3, 0xa9, 0x46, 0xe1,
+  0x7c, 0x00, 0xc2, 0x62,
+  0x54, 0x08, 0x01, 0x00,
+  0x00, 0x06, 0x00, 0x08,  // username attribute (length 8)
+  0x61, 0x62, 0x63, 0x64,  // abcdefgh
+  0x65, 0x66, 0x67, 0x68
+};
+
+// Message with an unknown but comprehensible optional attribute.
+// Parsing should succeed despite this unknown attribute.
+static const unsigned char kStunMessageWithUnknownAttribute[] = {
+  0x00, 0x01, 0x00, 0x14,
+  0x21, 0x12, 0xa4, 0x42,
+  0xe3, 0xa9, 0x46, 0xe1,
+  0x7c, 0x00, 0xc2, 0x62,
+  0x54, 0x08, 0x01, 0x00,
+  0x00, 0xaa, 0x00, 0x07,  // Unknown attribute, length 7 (needs padding!)
+  0x61, 0x62, 0x63, 0x64,  // abcdefg + padding
+  0x65, 0x66, 0x67, 0x00,
+  0x00, 0x06, 0x00, 0x03,  // Followed by a known attribute we can
+  0x61, 0x62, 0x63, 0x00   // check for (username of length 3)
+};
+
+// ByteString Attribute (username) with padding byte
+static const unsigned char kStunMessageWithPaddedByteStringAttribute[] = {
+  0x00, 0x01, 0x00, 0x08,
+  0x21, 0x12, 0xa4, 0x42,
+  0xe3, 0xa9, 0x46, 0xe1,
+  0x7c, 0x00, 0xc2, 0x62,
+  0x54, 0x08, 0x01, 0x00,
+  0x00, 0x06, 0x00, 0x03,  // username attribute (length 3)
+  0x61, 0x62, 0x63, 0xcc   // abc
+};
+
+// Message with an Unknown Attributes (uint16 list) attribute.
+static const unsigned char kStunMessageWithUInt16ListAttribute[] = {
+  0x00, 0x01, 0x00, 0x0c,
+  0x21, 0x12, 0xa4, 0x42,
+  0xe3, 0xa9, 0x46, 0xe1,
+  0x7c, 0x00, 0xc2, 0x62,
+  0x54, 0x08, 0x01, 0x00,
+  0x00, 0x0a, 0x00, 0x06,  // username attribute (length 6)
+  0x00, 0x01, 0x10, 0x00,  // three attributes plus padding
+  0xAB, 0xCU, 0xBE, 0xEF
+};
+
+// Error response message (unauthorized)
+static const unsigned char kStunMessageWithErrorAttribute[] = {
+  0x01, 0x11, 0x00, 0x14,
+  0x21, 0x12, 0xa4, 0x42,
+  0x29, 0x1f, 0xcd, 0x7c,
+  0xba, 0x58, 0xab, 0xd7,
+  0xf2, 0x41, 0x01, 0x00,
+  0x00, 0x09, 0x00, 0x10,
+  0x00, 0x00, 0x04, 0x01,
+  0x55, 0x6e, 0x61, 0x75,
+  0x74, 0x68, 0x6f, 0x72,
+  0x69, 0x7a, 0x65, 0x64
+};
+
+// Sample messages with an invalid length Field
+
+// The actual length in bytes of the invalid messages (including STUN header)
+static const int kRealLengthOfInvalidLengthTestCases = 32;
+
+static const unsigned char kStunMessageWithZeroLength[] = {
+  0x00, 0x01, 0x00, 0x00,  // length of 0 (last 2 bytes)
+  0x21, 0x12, 0xA4, 0x42,  // magic cookie
+  '0', '1', '2', '3',      // transaction id
+  '4', '5', '6', '7',
+  '8', '9', 'a', 'b',
+  0x00, 0x20, 0x00, 0x08,  // xor mapped address
+  0x00, 0x01, 0x21, 0x1F,
+  0x21, 0x12, 0xA4, 0x53,
+};
+
+static const unsigned char kStunMessageWithExcessLength[] = {
+  0x00, 0x01, 0x00, 0x55,  // length of 85
+  0x21, 0x12, 0xA4, 0x42,  // magic cookie
+  '0', '1', '2', '3',      // transaction id
+  '4', '5', '6', '7',
+  '8', '9', 'a', 'b',
+  0x00, 0x20, 0x00, 0x08,  // xor mapped address
+  0x00, 0x01, 0x21, 0x1F,
+  0x21, 0x12, 0xA4, 0x53,
+};
+
+static const unsigned char kStunMessageWithSmallLength[] = {
+  0x00, 0x01, 0x00, 0x03,  // length of 3
+  0x21, 0x12, 0xA4, 0x42,  // magic cookie
+  '0', '1', '2', '3',      // transaction id
+  '4', '5', '6', '7',
+  '8', '9', 'a', 'b',
+  0x00, 0x20, 0x00, 0x08,  // xor mapped address
+  0x00, 0x01, 0x21, 0x1F,
+  0x21, 0x12, 0xA4, 0x53,
+};
+
+// RTCP packet, for testing we correctly ignore non stun packet types.
+// V=2, P=false, RC=0, Type=200, Len=6, Sender-SSRC=85, etc
+static const unsigned char kRtcpPacket[] = {
+  0x80, 0xc8, 0x00, 0x06, 0x00, 0x00, 0x00, 0x55,
+  0xce, 0xa5, 0x18, 0x3a, 0x39, 0xcc, 0x7d, 0x09,
+  0x23, 0xed, 0x19, 0x07, 0x00, 0x00, 0x01, 0x56,
+  0x00, 0x03, 0x73, 0x50,
+};
+
+// RFC5769 Test Vectors
+// Software name (request):  "STUN test client" (without quotes)
+// Software name (response): "test vector" (without quotes)
+// Username:  "evtj:h6vY" (without quotes)
+// Password:  "VOkJxbRl1RmTxUk/WvJxBt" (without quotes)
+static const unsigned char kRfc5769SampleMsgTransactionId[] = {
+  0xb7, 0xe7, 0xa7, 0x01, 0xbc, 0x34, 0xd6, 0x86, 0xfa, 0x87, 0xdf, 0xae
+};
+static const char kRfc5769SampleMsgClientSoftware[] = "STUN test client";
+static const char kRfc5769SampleMsgServerSoftware[] = "test vector";
+static const char kRfc5769SampleMsgUsername[] = "evtj:h6vY";
+static const char kRfc5769SampleMsgPassword[] = "VOkJxbRl1RmTxUk/WvJxBt";
+static const rtc::SocketAddress kRfc5769SampleMsgMappedAddress(
+    "192.0.2.1", 32853);
+static const rtc::SocketAddress kRfc5769SampleMsgIPv6MappedAddress(
+    "2001:db8:1234:5678:11:2233:4455:6677", 32853);
+
+static const unsigned char kRfc5769SampleMsgWithAuthTransactionId[] = {
+  0x78, 0xad, 0x34, 0x33, 0xc6, 0xad, 0x72, 0xc0, 0x29, 0xda, 0x41, 0x2e
+};
+static const char kRfc5769SampleMsgWithAuthUsername[] =
+    "\xe3\x83\x9e\xe3\x83\x88\xe3\x83\xaa\xe3\x83\x83\xe3\x82\xaf\xe3\x82\xb9";
+static const char kRfc5769SampleMsgWithAuthPassword[] = "TheMatrIX";
+static const char kRfc5769SampleMsgWithAuthNonce[] =
+    "f//499k954d6OL34oL9FSTvy64sA";
+static const char kRfc5769SampleMsgWithAuthRealm[] = "example.org";
+
+// 2.1.  Sample Request
+static const unsigned char kRfc5769SampleRequest[] = {
+  0x00, 0x01, 0x00, 0x58,   //    Request type and message length
+  0x21, 0x12, 0xa4, 0x42,   //    Magic cookie
+  0xb7, 0xe7, 0xa7, 0x01,   // }
+  0xbc, 0x34, 0xd6, 0x86,   // }  Transaction ID
+  0xfa, 0x87, 0xdf, 0xae,   // }
+  0x80, 0x22, 0x00, 0x10,   //    SOFTWARE attribute header
+  0x53, 0x54, 0x55, 0x4e,   // }
+  0x20, 0x74, 0x65, 0x73,   // }  User-agent...
+  0x74, 0x20, 0x63, 0x6c,   // }  ...name
+  0x69, 0x65, 0x6e, 0x74,   // }
+  0x00, 0x24, 0x00, 0x04,   //    PRIORITY attribute header
+  0x6e, 0x00, 0x01, 0xff,   //    ICE priority value
+  0x80, 0x29, 0x00, 0x08,   //    ICE-CONTROLLED attribute header
+  0x93, 0x2f, 0xf9, 0xb1,   // }  Pseudo-random tie breaker...
+  0x51, 0x26, 0x3b, 0x36,   // }   ...for ICE control
+  0x00, 0x06, 0x00, 0x09,   //    USERNAME attribute header
+  0x65, 0x76, 0x74, 0x6a,   // }
+  0x3a, 0x68, 0x36, 0x76,   // }  Username (9 bytes) and padding (3 bytes)
+  0x59, 0x20, 0x20, 0x20,   // }
+  0x00, 0x08, 0x00, 0x14,   //    MESSAGE-INTEGRITY attribute header
+  0x9a, 0xea, 0xa7, 0x0c,   // }
+  0xbf, 0xd8, 0xcb, 0x56,   // }
+  0x78, 0x1e, 0xf2, 0xb5,   // }  HMAC-SHA1 fingerprint
+  0xb2, 0xd3, 0xf2, 0x49,   // }
+  0xc1, 0xb5, 0x71, 0xa2,   // }
+  0x80, 0x28, 0x00, 0x04,   //    FINGERPRINT attribute header
+  0xe5, 0x7a, 0x3b, 0xcf    //    CRC32 fingerprint
+};
+
+// 2.2.  Sample IPv4 Response
+static const unsigned char kRfc5769SampleResponse[] = {
+  0x01, 0x01, 0x00, 0x3c,  //     Response type and message length
+  0x21, 0x12, 0xa4, 0x42,  //     Magic cookie
+  0xb7, 0xe7, 0xa7, 0x01,  // }
+  0xbc, 0x34, 0xd6, 0x86,  // }  Transaction ID
+  0xfa, 0x87, 0xdf, 0xae,  // }
+  0x80, 0x22, 0x00, 0x0b,  //    SOFTWARE attribute header
+  0x74, 0x65, 0x73, 0x74,  // }
+  0x20, 0x76, 0x65, 0x63,  // }  UTF-8 server name
+  0x74, 0x6f, 0x72, 0x20,  // }
+  0x00, 0x20, 0x00, 0x08,  //    XOR-MAPPED-ADDRESS attribute header
+  0x00, 0x01, 0xa1, 0x47,  //    Address family (IPv4) and xor'd mapped port
+  0xe1, 0x12, 0xa6, 0x43,  //    Xor'd mapped IPv4 address
+  0x00, 0x08, 0x00, 0x14,  //    MESSAGE-INTEGRITY attribute header
+  0x2b, 0x91, 0xf5, 0x99,  // }
+  0xfd, 0x9e, 0x90, 0xc3,  // }
+  0x8c, 0x74, 0x89, 0xf9,  // }  HMAC-SHA1 fingerprint
+  0x2a, 0xf9, 0xba, 0x53,  // }
+  0xf0, 0x6b, 0xe7, 0xd7,  // }
+  0x80, 0x28, 0x00, 0x04,  //    FINGERPRINT attribute header
+  0xc0, 0x7d, 0x4c, 0x96   //    CRC32 fingerprint
+};
+
+// 2.3.  Sample IPv6 Response
+static const unsigned char kRfc5769SampleResponseIPv6[] = {
+  0x01, 0x01, 0x00, 0x48,  //    Response type and message length
+  0x21, 0x12, 0xa4, 0x42,  //    Magic cookie
+  0xb7, 0xe7, 0xa7, 0x01,  // }
+  0xbc, 0x34, 0xd6, 0x86,  // }  Transaction ID
+  0xfa, 0x87, 0xdf, 0xae,  // }
+  0x80, 0x22, 0x00, 0x0b,  //    SOFTWARE attribute header
+  0x74, 0x65, 0x73, 0x74,  // }
+  0x20, 0x76, 0x65, 0x63,  // }  UTF-8 server name
+  0x74, 0x6f, 0x72, 0x20,  // }
+  0x00, 0x20, 0x00, 0x14,  //    XOR-MAPPED-ADDRESS attribute header
+  0x00, 0x02, 0xa1, 0x47,  //    Address family (IPv6) and xor'd mapped port.
+  0x01, 0x13, 0xa9, 0xfa,  // }
+  0xa5, 0xd3, 0xf1, 0x79,  // }  Xor'd mapped IPv6 address
+  0xbc, 0x25, 0xf4, 0xb5,  // }
+  0xbe, 0xd2, 0xb9, 0xd9,  // }
+  0x00, 0x08, 0x00, 0x14,  //    MESSAGE-INTEGRITY attribute header
+  0xa3, 0x82, 0x95, 0x4e,  // }
+  0x4b, 0xe6, 0x7b, 0xf1,  // }
+  0x17, 0x84, 0xc9, 0x7c,  // }  HMAC-SHA1 fingerprint
+  0x82, 0x92, 0xc2, 0x75,  // }
+  0xbf, 0xe3, 0xed, 0x41,  // }
+  0x80, 0x28, 0x00, 0x04,  //    FINGERPRINT attribute header
+  0xc8, 0xfb, 0x0b, 0x4c   //    CRC32 fingerprint
+};
+
+// 2.4.  Sample Request with Long-Term Authentication
+static const unsigned char kRfc5769SampleRequestLongTermAuth[] = {
+  0x00, 0x01, 0x00, 0x60,  //    Request type and message length
+  0x21, 0x12, 0xa4, 0x42,  //    Magic cookie
+  0x78, 0xad, 0x34, 0x33,  // }
+  0xc6, 0xad, 0x72, 0xc0,  // }  Transaction ID
+  0x29, 0xda, 0x41, 0x2e,  // }
+  0x00, 0x06, 0x00, 0x12,  //    USERNAME attribute header
+  0xe3, 0x83, 0x9e, 0xe3,  // }
+  0x83, 0x88, 0xe3, 0x83,  // }
+  0xaa, 0xe3, 0x83, 0x83,  // }  Username value (18 bytes) and padding (2 bytes)
+  0xe3, 0x82, 0xaf, 0xe3,  // }
+  0x82, 0xb9, 0x00, 0x00,  // }
+  0x00, 0x15, 0x00, 0x1c,  //    NONCE attribute header
+  0x66, 0x2f, 0x2f, 0x34,  // }
+  0x39, 0x39, 0x6b, 0x39,  // }
+  0x35, 0x34, 0x64, 0x36,  // }
+  0x4f, 0x4c, 0x33, 0x34,  // }  Nonce value
+  0x6f, 0x4c, 0x39, 0x46,  // }
+  0x53, 0x54, 0x76, 0x79,  // }
+  0x36, 0x34, 0x73, 0x41,  // }
+  0x00, 0x14, 0x00, 0x0b,  //    REALM attribute header
+  0x65, 0x78, 0x61, 0x6d,  // }
+  0x70, 0x6c, 0x65, 0x2e,  // }  Realm value (11 bytes) and padding (1 byte)
+  0x6f, 0x72, 0x67, 0x00,  // }
+  0x00, 0x08, 0x00, 0x14,  //    MESSAGE-INTEGRITY attribute header
+  0xf6, 0x70, 0x24, 0x65,  // }
+  0x6d, 0xd6, 0x4a, 0x3e,  // }
+  0x02, 0xb8, 0xe0, 0x71,  // }  HMAC-SHA1 fingerprint
+  0x2e, 0x85, 0xc9, 0xa2,  // }
+  0x8c, 0xa8, 0x96, 0x66   // }
+};
+
+// Length parameter is changed to 0x38 from 0x58.
+// AddMessageIntegrity will add MI information and update the length param
+// accordingly.
+static const unsigned char kRfc5769SampleRequestWithoutMI[] = {
+  0x00, 0x01, 0x00, 0x38,  //    Request type and message length
+  0x21, 0x12, 0xa4, 0x42,  //    Magic cookie
+  0xb7, 0xe7, 0xa7, 0x01,  // }
+  0xbc, 0x34, 0xd6, 0x86,  // }  Transaction ID
+  0xfa, 0x87, 0xdf, 0xae,  // }
+  0x80, 0x22, 0x00, 0x10,  //    SOFTWARE attribute header
+  0x53, 0x54, 0x55, 0x4e,  // }
+  0x20, 0x74, 0x65, 0x73,  // }  User-agent...
+  0x74, 0x20, 0x63, 0x6c,  // }  ...name
+  0x69, 0x65, 0x6e, 0x74,  // }
+  0x00, 0x24, 0x00, 0x04,  //    PRIORITY attribute header
+  0x6e, 0x00, 0x01, 0xff,  //    ICE priority value
+  0x80, 0x29, 0x00, 0x08,  //    ICE-CONTROLLED attribute header
+  0x93, 0x2f, 0xf9, 0xb1,  // }  Pseudo-random tie breaker...
+  0x51, 0x26, 0x3b, 0x36,  // }   ...for ICE control
+  0x00, 0x06, 0x00, 0x09,  //    USERNAME attribute header
+  0x65, 0x76, 0x74, 0x6a,  // }
+  0x3a, 0x68, 0x36, 0x76,  // }  Username (9 bytes) and padding (3 bytes)
+  0x59, 0x20, 0x20, 0x20   // }
+};
+
+// This HMAC differs from the RFC 5769 SampleRequest message. This differs
+// because spec uses 0x20 for the padding where as our implementation uses 0.
+static const unsigned char kCalculatedHmac1[] = {
+  0x79, 0x07, 0xc2, 0xd2,  // }
+  0xed, 0xbf, 0xea, 0x48,  // }
+  0x0e, 0x4c, 0x76, 0xd8,  // }  HMAC-SHA1 fingerprint
+  0x29, 0x62, 0xd5, 0xc3,  // }
+  0x74, 0x2a, 0xf9, 0xe3   // }
+};
+
+// Length parameter is changed to 0x1c from 0x3c.
+// AddMessageIntegrity will add MI information and update the length param
+// accordingly.
+static const unsigned char kRfc5769SampleResponseWithoutMI[] = {
+  0x01, 0x01, 0x00, 0x1c,  //    Response type and message length
+  0x21, 0x12, 0xa4, 0x42,  //    Magic cookie
+  0xb7, 0xe7, 0xa7, 0x01,  // }
+  0xbc, 0x34, 0xd6, 0x86,  // }  Transaction ID
+  0xfa, 0x87, 0xdf, 0xae,  // }
+  0x80, 0x22, 0x00, 0x0b,  //    SOFTWARE attribute header
+  0x74, 0x65, 0x73, 0x74,  // }
+  0x20, 0x76, 0x65, 0x63,  // }  UTF-8 server name
+  0x74, 0x6f, 0x72, 0x20,  // }
+  0x00, 0x20, 0x00, 0x08,  //    XOR-MAPPED-ADDRESS attribute header
+  0x00, 0x01, 0xa1, 0x47,  //    Address family (IPv4) and xor'd mapped port
+  0xe1, 0x12, 0xa6, 0x43   //    Xor'd mapped IPv4 address
+};
+
+// This HMAC differs from the RFC 5769 SampleResponse message. This differs
+// because spec uses 0x20 for the padding where as our implementation uses 0.
+static const unsigned char kCalculatedHmac2[] = {
+  0x5d, 0x6b, 0x58, 0xbe,  // }
+  0xad, 0x94, 0xe0, 0x7e,  // }
+  0xef, 0x0d, 0xfc, 0x12,  // }  HMAC-SHA1 fingerprint
+  0x82, 0xa2, 0xbd, 0x08,  // }
+  0x43, 0x14, 0x10, 0x28   // }
+};
+
+// A transaction ID without the 'magic cookie' portion
+// pjnat's test programs use this transaction ID a lot.
+const unsigned char kTestTransactionId1[] = { 0x029, 0x01f, 0x0cd, 0x07c,
+                                              0x0ba, 0x058, 0x0ab, 0x0d7,
+                                              0x0f2, 0x041, 0x001, 0x000 };
+
+// They use this one sometimes too.
+const unsigned char kTestTransactionId2[] = { 0x0e3, 0x0a9, 0x046, 0x0e1,
+                                              0x07c, 0x000, 0x0c2, 0x062,
+                                              0x054, 0x008, 0x001, 0x000 };
+
+const in6_addr kIPv6TestAddress1 = { { { 0x24, 0x01, 0xfa, 0x00,
+                                         0x00, 0x04, 0x10, 0x00,
+                                         0xbe, 0x30, 0x5b, 0xff,
+                                         0xfe, 0xe5, 0x00, 0xc3 } } };
+const in6_addr kIPv6TestAddress2 = { { { 0x24, 0x01, 0xfa, 0x00,
+                                         0x00, 0x04, 0x10, 0x12,
+                                         0x06, 0x0c, 0xce, 0xff,
+                                         0xfe, 0x1f, 0x61, 0xa4 } } };
+
+#ifdef WEBRTC_POSIX
+const in_addr kIPv4TestAddress1 =  { 0xe64417ac };
+#elif defined WEBRTC_WIN
+// Windows in_addr has a union with a uchar[] array first.
+const in_addr kIPv4TestAddress1 =  { { 0x0ac, 0x017, 0x044, 0x0e6 } };
+#endif
+const char kTestUserName1[] = "abcdefgh";
+const char kTestUserName2[] = "abc";
+const char kTestErrorReason[] = "Unauthorized";
+const int kTestErrorClass = 4;
+const int kTestErrorNumber = 1;
+const int kTestErrorCode = 401;
+
+const int kTestMessagePort1 = 59977;
+const int kTestMessagePort2 = 47233;
+const int kTestMessagePort3 = 56743;
+const int kTestMessagePort4 = 40444;
+
+#define ReadStunMessage(X, Y) ReadStunMessageTestCase(X, Y, sizeof(Y));
+
+// Test that the GetStun*Type and IsStun*Type methods work as expected.
+TEST_F(StunTest, MessageTypes) {
+  EXPECT_EQ(STUN_BINDING_RESPONSE,
+      GetStunSuccessResponseType(STUN_BINDING_REQUEST));
+  EXPECT_EQ(STUN_BINDING_ERROR_RESPONSE,
+      GetStunErrorResponseType(STUN_BINDING_REQUEST));
+  EXPECT_EQ(-1, GetStunSuccessResponseType(STUN_BINDING_INDICATION));
+  EXPECT_EQ(-1, GetStunSuccessResponseType(STUN_BINDING_RESPONSE));
+  EXPECT_EQ(-1, GetStunSuccessResponseType(STUN_BINDING_ERROR_RESPONSE));
+  EXPECT_EQ(-1, GetStunErrorResponseType(STUN_BINDING_INDICATION));
+  EXPECT_EQ(-1, GetStunErrorResponseType(STUN_BINDING_RESPONSE));
+  EXPECT_EQ(-1, GetStunErrorResponseType(STUN_BINDING_ERROR_RESPONSE));
+
+  int types[] = {
+    STUN_BINDING_REQUEST, STUN_BINDING_INDICATION,
+    STUN_BINDING_RESPONSE, STUN_BINDING_ERROR_RESPONSE
+  };
+  for (int i = 0; i < ARRAY_SIZE(types); ++i) {
+    EXPECT_EQ(i == 0, IsStunRequestType(types[i]));
+    EXPECT_EQ(i == 1, IsStunIndicationType(types[i]));
+    EXPECT_EQ(i == 2, IsStunSuccessResponseType(types[i]));
+    EXPECT_EQ(i == 3, IsStunErrorResponseType(types[i]));
+    EXPECT_EQ(1, types[i] & 0xFEEF);
+  }
+}
+
+TEST_F(StunTest, ReadMessageWithIPv4AddressAttribute) {
+  StunMessage msg;
+  size_t size = ReadStunMessage(&msg, kStunMessageWithIPv4MappedAddress);
+  CheckStunHeader(msg, STUN_BINDING_RESPONSE, size);
+  CheckStunTransactionID(msg, kTestTransactionId1, kStunTransactionIdLength);
+
+  const StunAddressAttribute* addr = msg.GetAddress(STUN_ATTR_MAPPED_ADDRESS);
+  rtc::IPAddress test_address(kIPv4TestAddress1);
+  CheckStunAddressAttribute(addr, STUN_ADDRESS_IPV4,
+                            kTestMessagePort4, test_address);
+}
+
+TEST_F(StunTest, ReadMessageWithIPv4XorAddressAttribute) {
+  StunMessage msg;
+  StunMessage msg2;
+  size_t size = ReadStunMessage(&msg, kStunMessageWithIPv4XorMappedAddress);
+  CheckStunHeader(msg, STUN_BINDING_RESPONSE, size);
+  CheckStunTransactionID(msg, kTestTransactionId1, kStunTransactionIdLength);
+
+  const StunAddressAttribute* addr =
+      msg.GetAddress(STUN_ATTR_XOR_MAPPED_ADDRESS);
+  rtc::IPAddress test_address(kIPv4TestAddress1);
+  CheckStunAddressAttribute(addr, STUN_ADDRESS_IPV4,
+                            kTestMessagePort3, test_address);
+}
+
+TEST_F(StunTest, ReadMessageWithIPv6AddressAttribute) {
+  StunMessage msg;
+  size_t size = ReadStunMessage(&msg, kStunMessageWithIPv6MappedAddress);
+  CheckStunHeader(msg, STUN_BINDING_REQUEST, size);
+  CheckStunTransactionID(msg, kTestTransactionId1, kStunTransactionIdLength);
+
+  rtc::IPAddress test_address(kIPv6TestAddress1);
+
+  const StunAddressAttribute* addr = msg.GetAddress(STUN_ATTR_MAPPED_ADDRESS);
+  CheckStunAddressAttribute(addr, STUN_ADDRESS_IPV6,
+                            kTestMessagePort2, test_address);
+}
+
+TEST_F(StunTest, ReadMessageWithInvalidAddressAttribute) {
+  StunMessage msg;
+  size_t size = ReadStunMessage(&msg, kStunMessageWithIPv6MappedAddress);
+  CheckStunHeader(msg, STUN_BINDING_REQUEST, size);
+  CheckStunTransactionID(msg, kTestTransactionId1, kStunTransactionIdLength);
+
+  rtc::IPAddress test_address(kIPv6TestAddress1);
+
+  const StunAddressAttribute* addr = msg.GetAddress(STUN_ATTR_MAPPED_ADDRESS);
+  CheckStunAddressAttribute(addr, STUN_ADDRESS_IPV6,
+                            kTestMessagePort2, test_address);
+}
+
+TEST_F(StunTest, ReadMessageWithIPv6XorAddressAttribute) {
+  StunMessage msg;
+  size_t size = ReadStunMessage(&msg, kStunMessageWithIPv6XorMappedAddress);
+
+  rtc::IPAddress test_address(kIPv6TestAddress1);
+
+  CheckStunHeader(msg, STUN_BINDING_RESPONSE, size);
+  CheckStunTransactionID(msg, kTestTransactionId2, kStunTransactionIdLength);
+
+  const StunAddressAttribute* addr =
+      msg.GetAddress(STUN_ATTR_XOR_MAPPED_ADDRESS);
+  CheckStunAddressAttribute(addr, STUN_ADDRESS_IPV6,
+                            kTestMessagePort1, test_address);
+}
+
+// Read the RFC5389 fields from the RFC5769 sample STUN request.
+TEST_F(StunTest, ReadRfc5769RequestMessage) {
+  StunMessage msg;
+  size_t size = ReadStunMessage(&msg, kRfc5769SampleRequest);
+  CheckStunHeader(msg, STUN_BINDING_REQUEST, size);
+  CheckStunTransactionID(msg, kRfc5769SampleMsgTransactionId,
+                         kStunTransactionIdLength);
+
+  const StunByteStringAttribute* software =
+      msg.GetByteString(STUN_ATTR_SOFTWARE);
+  ASSERT_TRUE(software != NULL);
+  EXPECT_EQ(kRfc5769SampleMsgClientSoftware, software->GetString());
+
+  const StunByteStringAttribute* username =
+      msg.GetByteString(STUN_ATTR_USERNAME);
+  ASSERT_TRUE(username != NULL);
+  EXPECT_EQ(kRfc5769SampleMsgUsername, username->GetString());
+
+  // Actual M-I value checked in a later test.
+  ASSERT_TRUE(msg.GetByteString(STUN_ATTR_MESSAGE_INTEGRITY) != NULL);
+
+  // Fingerprint checked in a later test, but double-check the value here.
+  const StunUInt32Attribute* fingerprint =
+      msg.GetUInt32(STUN_ATTR_FINGERPRINT);
+  ASSERT_TRUE(fingerprint != NULL);
+  EXPECT_EQ(0xe57a3bcf, fingerprint->value());
+}
+
+// Read the RFC5389 fields from the RFC5769 sample STUN response.
+TEST_F(StunTest, ReadRfc5769ResponseMessage) {
+  StunMessage msg;
+  size_t size = ReadStunMessage(&msg, kRfc5769SampleResponse);
+  CheckStunHeader(msg, STUN_BINDING_RESPONSE, size);
+  CheckStunTransactionID(msg, kRfc5769SampleMsgTransactionId,
+                         kStunTransactionIdLength);
+
+  const StunByteStringAttribute* software =
+      msg.GetByteString(STUN_ATTR_SOFTWARE);
+  ASSERT_TRUE(software != NULL);
+  EXPECT_EQ(kRfc5769SampleMsgServerSoftware, software->GetString());
+
+  const StunAddressAttribute* mapped_address =
+      msg.GetAddress(STUN_ATTR_XOR_MAPPED_ADDRESS);
+  ASSERT_TRUE(mapped_address != NULL);
+  EXPECT_EQ(kRfc5769SampleMsgMappedAddress, mapped_address->GetAddress());
+
+  // Actual M-I and fingerprint checked in later tests.
+  ASSERT_TRUE(msg.GetByteString(STUN_ATTR_MESSAGE_INTEGRITY) != NULL);
+  ASSERT_TRUE(msg.GetUInt32(STUN_ATTR_FINGERPRINT) != NULL);
+}
+
+// Read the RFC5389 fields from the RFC5769 sample STUN response for IPv6.
+TEST_F(StunTest, ReadRfc5769ResponseMessageIPv6) {
+  StunMessage msg;
+  size_t size = ReadStunMessage(&msg, kRfc5769SampleResponseIPv6);
+  CheckStunHeader(msg, STUN_BINDING_RESPONSE, size);
+  CheckStunTransactionID(msg, kRfc5769SampleMsgTransactionId,
+                         kStunTransactionIdLength);
+
+  const StunByteStringAttribute* software =
+      msg.GetByteString(STUN_ATTR_SOFTWARE);
+  ASSERT_TRUE(software != NULL);
+  EXPECT_EQ(kRfc5769SampleMsgServerSoftware, software->GetString());
+
+  const StunAddressAttribute* mapped_address =
+      msg.GetAddress(STUN_ATTR_XOR_MAPPED_ADDRESS);
+  ASSERT_TRUE(mapped_address != NULL);
+  EXPECT_EQ(kRfc5769SampleMsgIPv6MappedAddress, mapped_address->GetAddress());
+
+  // Actual M-I and fingerprint checked in later tests.
+  ASSERT_TRUE(msg.GetByteString(STUN_ATTR_MESSAGE_INTEGRITY) != NULL);
+  ASSERT_TRUE(msg.GetUInt32(STUN_ATTR_FINGERPRINT) != NULL);
+}
+
+// Read the RFC5389 fields from the RFC5769 sample STUN response with auth.
+TEST_F(StunTest, ReadRfc5769RequestMessageLongTermAuth) {
+  StunMessage msg;
+  size_t size = ReadStunMessage(&msg, kRfc5769SampleRequestLongTermAuth);
+  CheckStunHeader(msg, STUN_BINDING_REQUEST, size);
+  CheckStunTransactionID(msg, kRfc5769SampleMsgWithAuthTransactionId,
+                         kStunTransactionIdLength);
+
+  const StunByteStringAttribute* username =
+      msg.GetByteString(STUN_ATTR_USERNAME);
+  ASSERT_TRUE(username != NULL);
+  EXPECT_EQ(kRfc5769SampleMsgWithAuthUsername, username->GetString());
+
+  const StunByteStringAttribute* nonce =
+      msg.GetByteString(STUN_ATTR_NONCE);
+  ASSERT_TRUE(nonce != NULL);
+  EXPECT_EQ(kRfc5769SampleMsgWithAuthNonce, nonce->GetString());
+
+  const StunByteStringAttribute* realm =
+      msg.GetByteString(STUN_ATTR_REALM);
+  ASSERT_TRUE(realm != NULL);
+  EXPECT_EQ(kRfc5769SampleMsgWithAuthRealm, realm->GetString());
+
+  // No fingerprint, actual M-I checked in later tests.
+  ASSERT_TRUE(msg.GetByteString(STUN_ATTR_MESSAGE_INTEGRITY) != NULL);
+  ASSERT_TRUE(msg.GetUInt32(STUN_ATTR_FINGERPRINT) == NULL);
+}
+
+// The RFC3489 packet in this test is the same as
+// kStunMessageWithIPv4MappedAddress, but with a different value where the
+// magic cookie was.
+TEST_F(StunTest, ReadLegacyMessage) {
+  unsigned char rfc3489_packet[sizeof(kStunMessageWithIPv4MappedAddress)];
+  memcpy(rfc3489_packet, kStunMessageWithIPv4MappedAddress,
+      sizeof(kStunMessageWithIPv4MappedAddress));
+  // Overwrite the magic cookie here.
+  memcpy(&rfc3489_packet[4], "ABCD", 4);
+
+  StunMessage msg;
+  size_t size = ReadStunMessage(&msg, rfc3489_packet);
+  CheckStunHeader(msg, STUN_BINDING_RESPONSE, size);
+  CheckStunTransactionID(msg, &rfc3489_packet[4], kStunTransactionIdLength + 4);
+
+  const StunAddressAttribute* addr = msg.GetAddress(STUN_ATTR_MAPPED_ADDRESS);
+  rtc::IPAddress test_address(kIPv4TestAddress1);
+  CheckStunAddressAttribute(addr, STUN_ADDRESS_IPV4,
+                            kTestMessagePort4, test_address);
+}
+
+TEST_F(StunTest, SetIPv6XorAddressAttributeOwner) {
+  StunMessage msg;
+  StunMessage msg2;
+  size_t size = ReadStunMessage(&msg, kStunMessageWithIPv6XorMappedAddress);
+
+  rtc::IPAddress test_address(kIPv6TestAddress1);
+
+  CheckStunHeader(msg, STUN_BINDING_RESPONSE, size);
+  CheckStunTransactionID(msg, kTestTransactionId2, kStunTransactionIdLength);
+
+  const StunAddressAttribute* addr =
+      msg.GetAddress(STUN_ATTR_XOR_MAPPED_ADDRESS);
+  CheckStunAddressAttribute(addr, STUN_ADDRESS_IPV6,
+                            kTestMessagePort1, test_address);
+
+  // Owner with a different transaction ID.
+  msg2.SetTransactionID("ABCDABCDABCD");
+  StunXorAddressAttribute addr2(STUN_ATTR_XOR_MAPPED_ADDRESS, 20, NULL);
+  addr2.SetIP(addr->ipaddr());
+  addr2.SetPort(addr->port());
+  addr2.SetOwner(&msg2);
+  // The internal IP address shouldn't change.
+  ASSERT_EQ(addr2.ipaddr(), addr->ipaddr());
+
+  rtc::ByteBuffer correct_buf;
+  rtc::ByteBuffer wrong_buf;
+  EXPECT_TRUE(addr->Write(&correct_buf));
+  EXPECT_TRUE(addr2.Write(&wrong_buf));
+  // But when written out, the buffers should look different.
+  ASSERT_NE(0,
+            memcmp(correct_buf.Data(), wrong_buf.Data(), wrong_buf.Length()));
+  // And when reading a known good value, the address should be wrong.
+  addr2.Read(&correct_buf);
+  ASSERT_NE(addr->ipaddr(), addr2.ipaddr());
+  addr2.SetIP(addr->ipaddr());
+  addr2.SetPort(addr->port());
+  // Try writing with no owner at all, should fail and write nothing.
+  addr2.SetOwner(NULL);
+  ASSERT_EQ(addr2.ipaddr(), addr->ipaddr());
+  wrong_buf.Consume(wrong_buf.Length());
+  EXPECT_FALSE(addr2.Write(&wrong_buf));
+  ASSERT_EQ(0U, wrong_buf.Length());
+}
+
+TEST_F(StunTest, SetIPv4XorAddressAttributeOwner) {
+  // Unlike the IPv6XorAddressAttributeOwner test, IPv4 XOR address attributes
+  // should _not_ be affected by a change in owner. IPv4 XOR address uses the
+  // magic cookie value which is fixed.
+  StunMessage msg;
+  StunMessage msg2;
+  size_t size = ReadStunMessage(&msg, kStunMessageWithIPv4XorMappedAddress);
+
+  rtc::IPAddress test_address(kIPv4TestAddress1);
+
+  CheckStunHeader(msg, STUN_BINDING_RESPONSE, size);
+  CheckStunTransactionID(msg, kTestTransactionId1, kStunTransactionIdLength);
+
+  const StunAddressAttribute* addr =
+      msg.GetAddress(STUN_ATTR_XOR_MAPPED_ADDRESS);
+  CheckStunAddressAttribute(addr, STUN_ADDRESS_IPV4,
+                            kTestMessagePort3, test_address);
+
+  // Owner with a different transaction ID.
+  msg2.SetTransactionID("ABCDABCDABCD");
+  StunXorAddressAttribute addr2(STUN_ATTR_XOR_MAPPED_ADDRESS, 20, NULL);
+  addr2.SetIP(addr->ipaddr());
+  addr2.SetPort(addr->port());
+  addr2.SetOwner(&msg2);
+  // The internal IP address shouldn't change.
+  ASSERT_EQ(addr2.ipaddr(), addr->ipaddr());
+
+  rtc::ByteBuffer correct_buf;
+  rtc::ByteBuffer wrong_buf;
+  EXPECT_TRUE(addr->Write(&correct_buf));
+  EXPECT_TRUE(addr2.Write(&wrong_buf));
+  // The same address data should be written.
+  ASSERT_EQ(0,
+            memcmp(correct_buf.Data(), wrong_buf.Data(), wrong_buf.Length()));
+  // And an attribute should be able to un-XOR an address belonging to a message
+  // with a different transaction ID.
+  EXPECT_TRUE(addr2.Read(&correct_buf));
+  ASSERT_EQ(addr->ipaddr(), addr2.ipaddr());
+
+  // However, no owner is still an error, should fail and write nothing.
+  addr2.SetOwner(NULL);
+  ASSERT_EQ(addr2.ipaddr(), addr->ipaddr());
+  wrong_buf.Consume(wrong_buf.Length());
+  EXPECT_FALSE(addr2.Write(&wrong_buf));
+}
+
+TEST_F(StunTest, CreateIPv6AddressAttribute) {
+  rtc::IPAddress test_ip(kIPv6TestAddress2);
+
+  StunAddressAttribute* addr =
+      StunAttribute::CreateAddress(STUN_ATTR_MAPPED_ADDRESS);
+  rtc::SocketAddress test_addr(test_ip, kTestMessagePort2);
+  addr->SetAddress(test_addr);
+
+  CheckStunAddressAttribute(addr, STUN_ADDRESS_IPV6,
+                            kTestMessagePort2, test_ip);
+  delete addr;
+}
+
+TEST_F(StunTest, CreateIPv4AddressAttribute) {
+  struct in_addr test_in_addr;
+  test_in_addr.s_addr = 0xBEB0B0BE;
+  rtc::IPAddress test_ip(test_in_addr);
+
+  StunAddressAttribute* addr =
+      StunAttribute::CreateAddress(STUN_ATTR_MAPPED_ADDRESS);
+  rtc::SocketAddress test_addr(test_ip, kTestMessagePort2);
+  addr->SetAddress(test_addr);
+
+  CheckStunAddressAttribute(addr, STUN_ADDRESS_IPV4,
+                            kTestMessagePort2, test_ip);
+  delete addr;
+}
+
+// Test that we don't care what order we set the parts of an address
+TEST_F(StunTest, CreateAddressInArbitraryOrder) {
+  StunAddressAttribute* addr =
+  StunAttribute::CreateAddress(STUN_ATTR_DESTINATION_ADDRESS);
+  // Port first
+  addr->SetPort(kTestMessagePort1);
+  addr->SetIP(rtc::IPAddress(kIPv4TestAddress1));
+  ASSERT_EQ(kTestMessagePort1, addr->port());
+  ASSERT_EQ(rtc::IPAddress(kIPv4TestAddress1), addr->ipaddr());
+
+  StunAddressAttribute* addr2 =
+  StunAttribute::CreateAddress(STUN_ATTR_DESTINATION_ADDRESS);
+  // IP first
+  addr2->SetIP(rtc::IPAddress(kIPv4TestAddress1));
+  addr2->SetPort(kTestMessagePort2);
+  ASSERT_EQ(kTestMessagePort2, addr2->port());
+  ASSERT_EQ(rtc::IPAddress(kIPv4TestAddress1), addr2->ipaddr());
+
+  delete addr;
+  delete addr2;
+}
+
+TEST_F(StunTest, WriteMessageWithIPv6AddressAttribute) {
+  StunMessage msg;
+  size_t size = sizeof(kStunMessageWithIPv6MappedAddress);
+
+  rtc::IPAddress test_ip(kIPv6TestAddress1);
+
+  msg.SetType(STUN_BINDING_REQUEST);
+  msg.SetTransactionID(
+      std::string(reinterpret_cast<const char*>(kTestTransactionId1),
+                  kStunTransactionIdLength));
+  CheckStunTransactionID(msg, kTestTransactionId1, kStunTransactionIdLength);
+
+  StunAddressAttribute* addr =
+      StunAttribute::CreateAddress(STUN_ATTR_MAPPED_ADDRESS);
+  rtc::SocketAddress test_addr(test_ip, kTestMessagePort2);
+  addr->SetAddress(test_addr);
+  EXPECT_TRUE(msg.AddAttribute(addr));
+
+  CheckStunHeader(msg, STUN_BINDING_REQUEST, (size - 20));
+
+  rtc::ByteBuffer out;
+  EXPECT_TRUE(msg.Write(&out));
+  ASSERT_EQ(out.Length(), sizeof(kStunMessageWithIPv6MappedAddress));
+  int len1 = static_cast<int>(out.Length());
+  std::string bytes;
+  out.ReadString(&bytes, len1);
+  ASSERT_EQ(0, memcmp(bytes.c_str(), kStunMessageWithIPv6MappedAddress, len1));
+}
+
+TEST_F(StunTest, WriteMessageWithIPv4AddressAttribute) {
+  StunMessage msg;
+  size_t size = sizeof(kStunMessageWithIPv4MappedAddress);
+
+  rtc::IPAddress test_ip(kIPv4TestAddress1);
+
+  msg.SetType(STUN_BINDING_RESPONSE);
+  msg.SetTransactionID(
+      std::string(reinterpret_cast<const char*>(kTestTransactionId1),
+                  kStunTransactionIdLength));
+  CheckStunTransactionID(msg, kTestTransactionId1, kStunTransactionIdLength);
+
+  StunAddressAttribute* addr =
+      StunAttribute::CreateAddress(STUN_ATTR_MAPPED_ADDRESS);
+  rtc::SocketAddress test_addr(test_ip, kTestMessagePort4);
+  addr->SetAddress(test_addr);
+  EXPECT_TRUE(msg.AddAttribute(addr));
+
+  CheckStunHeader(msg, STUN_BINDING_RESPONSE, (size - 20));
+
+  rtc::ByteBuffer out;
+  EXPECT_TRUE(msg.Write(&out));
+  ASSERT_EQ(out.Length(), sizeof(kStunMessageWithIPv4MappedAddress));
+  int len1 = static_cast<int>(out.Length());
+  std::string bytes;
+  out.ReadString(&bytes, len1);
+  ASSERT_EQ(0, memcmp(bytes.c_str(), kStunMessageWithIPv4MappedAddress, len1));
+}
+
+TEST_F(StunTest, WriteMessageWithIPv6XorAddressAttribute) {
+  StunMessage msg;
+  size_t size = sizeof(kStunMessageWithIPv6XorMappedAddress);
+
+  rtc::IPAddress test_ip(kIPv6TestAddress1);
+
+  msg.SetType(STUN_BINDING_RESPONSE);
+  msg.SetTransactionID(
+      std::string(reinterpret_cast<const char*>(kTestTransactionId2),
+                  kStunTransactionIdLength));
+  CheckStunTransactionID(msg, kTestTransactionId2, kStunTransactionIdLength);
+
+  StunAddressAttribute* addr =
+      StunAttribute::CreateXorAddress(STUN_ATTR_XOR_MAPPED_ADDRESS);
+  rtc::SocketAddress test_addr(test_ip, kTestMessagePort1);
+  addr->SetAddress(test_addr);
+  EXPECT_TRUE(msg.AddAttribute(addr));
+
+  CheckStunHeader(msg, STUN_BINDING_RESPONSE, (size - 20));
+
+  rtc::ByteBuffer out;
+  EXPECT_TRUE(msg.Write(&out));
+  ASSERT_EQ(out.Length(), sizeof(kStunMessageWithIPv6XorMappedAddress));
+  int len1 = static_cast<int>(out.Length());
+  std::string bytes;
+  out.ReadString(&bytes, len1);
+  ASSERT_EQ(0,
+            memcmp(bytes.c_str(), kStunMessageWithIPv6XorMappedAddress, len1));
+}
+
+TEST_F(StunTest, WriteMessageWithIPv4XoreAddressAttribute) {
+  StunMessage msg;
+  size_t size = sizeof(kStunMessageWithIPv4XorMappedAddress);
+
+  rtc::IPAddress test_ip(kIPv4TestAddress1);
+
+  msg.SetType(STUN_BINDING_RESPONSE);
+  msg.SetTransactionID(
+      std::string(reinterpret_cast<const char*>(kTestTransactionId1),
+                  kStunTransactionIdLength));
+  CheckStunTransactionID(msg, kTestTransactionId1, kStunTransactionIdLength);
+
+  StunAddressAttribute* addr =
+      StunAttribute::CreateXorAddress(STUN_ATTR_XOR_MAPPED_ADDRESS);
+  rtc::SocketAddress test_addr(test_ip, kTestMessagePort3);
+  addr->SetAddress(test_addr);
+  EXPECT_TRUE(msg.AddAttribute(addr));
+
+  CheckStunHeader(msg, STUN_BINDING_RESPONSE, (size - 20));
+
+  rtc::ByteBuffer out;
+  EXPECT_TRUE(msg.Write(&out));
+  ASSERT_EQ(out.Length(), sizeof(kStunMessageWithIPv4XorMappedAddress));
+  int len1 = static_cast<int>(out.Length());
+  std::string bytes;
+  out.ReadString(&bytes, len1);
+  ASSERT_EQ(0,
+            memcmp(bytes.c_str(), kStunMessageWithIPv4XorMappedAddress, len1));
+}
+
+TEST_F(StunTest, ReadByteStringAttribute) {
+  StunMessage msg;
+  size_t size = ReadStunMessage(&msg, kStunMessageWithByteStringAttribute);
+
+  CheckStunHeader(msg, STUN_BINDING_REQUEST, size);
+  CheckStunTransactionID(msg, kTestTransactionId2, kStunTransactionIdLength);
+  const StunByteStringAttribute* username =
+      msg.GetByteString(STUN_ATTR_USERNAME);
+  ASSERT_TRUE(username != NULL);
+  EXPECT_EQ(kTestUserName1, username->GetString());
+}
+
+TEST_F(StunTest, ReadPaddedByteStringAttribute) {
+  StunMessage msg;
+  size_t size = ReadStunMessage(&msg,
+                                kStunMessageWithPaddedByteStringAttribute);
+  ASSERT_NE(0U, size);
+  CheckStunHeader(msg, STUN_BINDING_REQUEST, size);
+  CheckStunTransactionID(msg, kTestTransactionId2, kStunTransactionIdLength);
+  const StunByteStringAttribute* username =
+      msg.GetByteString(STUN_ATTR_USERNAME);
+  ASSERT_TRUE(username != NULL);
+  EXPECT_EQ(kTestUserName2, username->GetString());
+}
+
+TEST_F(StunTest, ReadErrorCodeAttribute) {
+  StunMessage msg;
+  size_t size = ReadStunMessage(&msg, kStunMessageWithErrorAttribute);
+
+  CheckStunHeader(msg, STUN_BINDING_ERROR_RESPONSE, size);
+  CheckStunTransactionID(msg, kTestTransactionId1, kStunTransactionIdLength);
+  const StunErrorCodeAttribute* errorcode = msg.GetErrorCode();
+  ASSERT_TRUE(errorcode != NULL);
+  EXPECT_EQ(kTestErrorClass, errorcode->eclass());
+  EXPECT_EQ(kTestErrorNumber, errorcode->number());
+  EXPECT_EQ(kTestErrorReason, errorcode->reason());
+  EXPECT_EQ(kTestErrorCode, errorcode->code());
+}
+
+TEST_F(StunTest, ReadMessageWithAUInt16ListAttribute) {
+  StunMessage msg;
+  size_t size = ReadStunMessage(&msg, kStunMessageWithUInt16ListAttribute);
+  CheckStunHeader(msg, STUN_BINDING_REQUEST, size);
+  const StunUInt16ListAttribute* types = msg.GetUnknownAttributes();
+  ASSERT_TRUE(types != NULL);
+  EXPECT_EQ(3U, types->Size());
+  EXPECT_EQ(0x1U, types->GetType(0));
+  EXPECT_EQ(0x1000U, types->GetType(1));
+  EXPECT_EQ(0xAB0CU, types->GetType(2));
+}
+
+TEST_F(StunTest, ReadMessageWithAnUnknownAttribute) {
+  StunMessage msg;
+  size_t size = ReadStunMessage(&msg, kStunMessageWithUnknownAttribute);
+  CheckStunHeader(msg, STUN_BINDING_REQUEST, size);
+
+  // Parsing should have succeeded and there should be a USERNAME attribute
+  const StunByteStringAttribute* username =
+      msg.GetByteString(STUN_ATTR_USERNAME);
+  ASSERT_TRUE(username != NULL);
+  EXPECT_EQ(kTestUserName2, username->GetString());
+}
+
+TEST_F(StunTest, WriteMessageWithAnErrorCodeAttribute) {
+  StunMessage msg;
+  size_t size = sizeof(kStunMessageWithErrorAttribute);
+
+  msg.SetType(STUN_BINDING_ERROR_RESPONSE);
+  msg.SetTransactionID(
+      std::string(reinterpret_cast<const char*>(kTestTransactionId1),
+                  kStunTransactionIdLength));
+  CheckStunTransactionID(msg, kTestTransactionId1, kStunTransactionIdLength);
+  StunErrorCodeAttribute* errorcode = StunAttribute::CreateErrorCode();
+  errorcode->SetCode(kTestErrorCode);
+  errorcode->SetReason(kTestErrorReason);
+  EXPECT_TRUE(msg.AddAttribute(errorcode));
+  CheckStunHeader(msg, STUN_BINDING_ERROR_RESPONSE, (size - 20));
+
+  rtc::ByteBuffer out;
+  EXPECT_TRUE(msg.Write(&out));
+  ASSERT_EQ(size, out.Length());
+  // No padding.
+  ASSERT_EQ(0, memcmp(out.Data(), kStunMessageWithErrorAttribute, size));
+}
+
+TEST_F(StunTest, WriteMessageWithAUInt16ListAttribute) {
+  StunMessage msg;
+  size_t size = sizeof(kStunMessageWithUInt16ListAttribute);
+
+  msg.SetType(STUN_BINDING_REQUEST);
+  msg.SetTransactionID(
+      std::string(reinterpret_cast<const char*>(kTestTransactionId2),
+                  kStunTransactionIdLength));
+  CheckStunTransactionID(msg, kTestTransactionId2, kStunTransactionIdLength);
+  StunUInt16ListAttribute* list = StunAttribute::CreateUnknownAttributes();
+  list->AddType(0x1U);
+  list->AddType(0x1000U);
+  list->AddType(0xAB0CU);
+  EXPECT_TRUE(msg.AddAttribute(list));
+  CheckStunHeader(msg, STUN_BINDING_REQUEST, (size - 20));
+
+  rtc::ByteBuffer out;
+  EXPECT_TRUE(msg.Write(&out));
+  ASSERT_EQ(size, out.Length());
+  // Check everything up to the padding.
+  ASSERT_EQ(0,
+            memcmp(out.Data(), kStunMessageWithUInt16ListAttribute, size - 2));
+}
+
+// Test that we fail to read messages with invalid lengths.
+void CheckFailureToRead(const unsigned char* testcase, size_t length) {
+  StunMessage msg;
+  const char* input = reinterpret_cast<const char*>(testcase);
+  rtc::ByteBuffer buf(input, length);
+  ASSERT_FALSE(msg.Read(&buf));
+}
+
+TEST_F(StunTest, FailToReadInvalidMessages) {
+  CheckFailureToRead(kStunMessageWithZeroLength,
+                     kRealLengthOfInvalidLengthTestCases);
+  CheckFailureToRead(kStunMessageWithSmallLength,
+                     kRealLengthOfInvalidLengthTestCases);
+  CheckFailureToRead(kStunMessageWithExcessLength,
+                     kRealLengthOfInvalidLengthTestCases);
+}
+
+// Test that we properly fail to read a non-STUN message.
+TEST_F(StunTest, FailToReadRtcpPacket) {
+  CheckFailureToRead(kRtcpPacket, sizeof(kRtcpPacket));
+}
+
+// Check our STUN message validation code against the RFC5769 test messages.
+TEST_F(StunTest, ValidateMessageIntegrity) {
+  // Try the messages from RFC 5769.
+  EXPECT_TRUE(StunMessage::ValidateMessageIntegrity(
+      reinterpret_cast<const char*>(kRfc5769SampleRequest),
+      sizeof(kRfc5769SampleRequest),
+      kRfc5769SampleMsgPassword));
+  EXPECT_FALSE(StunMessage::ValidateMessageIntegrity(
+      reinterpret_cast<const char*>(kRfc5769SampleRequest),
+      sizeof(kRfc5769SampleRequest),
+      "InvalidPassword"));
+
+  EXPECT_TRUE(StunMessage::ValidateMessageIntegrity(
+      reinterpret_cast<const char*>(kRfc5769SampleResponse),
+      sizeof(kRfc5769SampleResponse),
+      kRfc5769SampleMsgPassword));
+  EXPECT_FALSE(StunMessage::ValidateMessageIntegrity(
+      reinterpret_cast<const char*>(kRfc5769SampleResponse),
+      sizeof(kRfc5769SampleResponse),
+      "InvalidPassword"));
+
+  EXPECT_TRUE(StunMessage::ValidateMessageIntegrity(
+      reinterpret_cast<const char*>(kRfc5769SampleResponseIPv6),
+      sizeof(kRfc5769SampleResponseIPv6),
+      kRfc5769SampleMsgPassword));
+  EXPECT_FALSE(StunMessage::ValidateMessageIntegrity(
+      reinterpret_cast<const char*>(kRfc5769SampleResponseIPv6),
+      sizeof(kRfc5769SampleResponseIPv6),
+      "InvalidPassword"));
+
+  // We first need to compute the key for the long-term authentication HMAC.
+  std::string key;
+  ComputeStunCredentialHash(kRfc5769SampleMsgWithAuthUsername,
+      kRfc5769SampleMsgWithAuthRealm, kRfc5769SampleMsgWithAuthPassword, &key);
+  EXPECT_TRUE(StunMessage::ValidateMessageIntegrity(
+      reinterpret_cast<const char*>(kRfc5769SampleRequestLongTermAuth),
+      sizeof(kRfc5769SampleRequestLongTermAuth), key));
+  EXPECT_FALSE(StunMessage::ValidateMessageIntegrity(
+      reinterpret_cast<const char*>(kRfc5769SampleRequestLongTermAuth),
+      sizeof(kRfc5769SampleRequestLongTermAuth),
+      "InvalidPassword"));
+
+  // Try some edge cases.
+  EXPECT_FALSE(StunMessage::ValidateMessageIntegrity(
+      reinterpret_cast<const char*>(kStunMessageWithZeroLength),
+      sizeof(kStunMessageWithZeroLength),
+      kRfc5769SampleMsgPassword));
+  EXPECT_FALSE(StunMessage::ValidateMessageIntegrity(
+      reinterpret_cast<const char*>(kStunMessageWithExcessLength),
+      sizeof(kStunMessageWithExcessLength),
+      kRfc5769SampleMsgPassword));
+  EXPECT_FALSE(StunMessage::ValidateMessageIntegrity(
+      reinterpret_cast<const char*>(kStunMessageWithSmallLength),
+      sizeof(kStunMessageWithSmallLength),
+      kRfc5769SampleMsgPassword));
+
+  // Test that munging a single bit anywhere in the message causes the
+  // message-integrity check to fail, unless it is after the M-I attribute.
+  char buf[sizeof(kRfc5769SampleRequest)];
+  memcpy(buf, kRfc5769SampleRequest, sizeof(kRfc5769SampleRequest));
+  for (size_t i = 0; i < sizeof(buf); ++i) {
+    buf[i] ^= 0x01;
+    if (i > 0)
+      buf[i - 1] ^= 0x01;
+    EXPECT_EQ(i >= sizeof(buf) - 8, StunMessage::ValidateMessageIntegrity(
+        buf, sizeof(buf), kRfc5769SampleMsgPassword));
+  }
+}
+
+// Validate that we generate correct MESSAGE-INTEGRITY attributes.
+// Note the use of IceMessage instead of StunMessage; this is necessary because
+// the RFC5769 test messages used include attributes not found in basic STUN.
+TEST_F(StunTest, AddMessageIntegrity) {
+  IceMessage msg;
+  rtc::ByteBuffer buf(
+      reinterpret_cast<const char*>(kRfc5769SampleRequestWithoutMI),
+      sizeof(kRfc5769SampleRequestWithoutMI));
+  EXPECT_TRUE(msg.Read(&buf));
+  EXPECT_TRUE(msg.AddMessageIntegrity(kRfc5769SampleMsgPassword));
+  const StunByteStringAttribute* mi_attr =
+      msg.GetByteString(STUN_ATTR_MESSAGE_INTEGRITY);
+  EXPECT_EQ(20U, mi_attr->length());
+  EXPECT_EQ(0, memcmp(
+      mi_attr->bytes(), kCalculatedHmac1, sizeof(kCalculatedHmac1)));
+
+  rtc::ByteBuffer buf1;
+  EXPECT_TRUE(msg.Write(&buf1));
+  EXPECT_TRUE(StunMessage::ValidateMessageIntegrity(
+        reinterpret_cast<const char*>(buf1.Data()), buf1.Length(),
+        kRfc5769SampleMsgPassword));
+
+  IceMessage msg2;
+  rtc::ByteBuffer buf2(
+      reinterpret_cast<const char*>(kRfc5769SampleResponseWithoutMI),
+      sizeof(kRfc5769SampleResponseWithoutMI));
+  EXPECT_TRUE(msg2.Read(&buf2));
+  EXPECT_TRUE(msg2.AddMessageIntegrity(kRfc5769SampleMsgPassword));
+  const StunByteStringAttribute* mi_attr2 =
+      msg2.GetByteString(STUN_ATTR_MESSAGE_INTEGRITY);
+  EXPECT_EQ(20U, mi_attr2->length());
+  EXPECT_EQ(
+      0, memcmp(mi_attr2->bytes(), kCalculatedHmac2, sizeof(kCalculatedHmac2)));
+
+  rtc::ByteBuffer buf3;
+  EXPECT_TRUE(msg2.Write(&buf3));
+  EXPECT_TRUE(StunMessage::ValidateMessageIntegrity(
+        reinterpret_cast<const char*>(buf3.Data()), buf3.Length(),
+        kRfc5769SampleMsgPassword));
+}
+
+// Check our STUN message validation code against the RFC5769 test messages.
+TEST_F(StunTest, ValidateFingerprint) {
+  EXPECT_TRUE(StunMessage::ValidateFingerprint(
+      reinterpret_cast<const char*>(kRfc5769SampleRequest),
+      sizeof(kRfc5769SampleRequest)));
+  EXPECT_TRUE(StunMessage::ValidateFingerprint(
+      reinterpret_cast<const char*>(kRfc5769SampleResponse),
+      sizeof(kRfc5769SampleResponse)));
+  EXPECT_TRUE(StunMessage::ValidateFingerprint(
+      reinterpret_cast<const char*>(kRfc5769SampleResponseIPv6),
+      sizeof(kRfc5769SampleResponseIPv6)));
+
+  EXPECT_FALSE(StunMessage::ValidateFingerprint(
+      reinterpret_cast<const char*>(kStunMessageWithZeroLength),
+      sizeof(kStunMessageWithZeroLength)));
+  EXPECT_FALSE(StunMessage::ValidateFingerprint(
+      reinterpret_cast<const char*>(kStunMessageWithExcessLength),
+      sizeof(kStunMessageWithExcessLength)));
+  EXPECT_FALSE(StunMessage::ValidateFingerprint(
+      reinterpret_cast<const char*>(kStunMessageWithSmallLength),
+      sizeof(kStunMessageWithSmallLength)));
+
+  // Test that munging a single bit anywhere in the message causes the
+  // fingerprint check to fail.
+  char buf[sizeof(kRfc5769SampleRequest)];
+  memcpy(buf, kRfc5769SampleRequest, sizeof(kRfc5769SampleRequest));
+  for (size_t i = 0; i < sizeof(buf); ++i) {
+    buf[i] ^= 0x01;
+    if (i > 0)
+      buf[i - 1] ^= 0x01;
+    EXPECT_FALSE(StunMessage::ValidateFingerprint(buf, sizeof(buf)));
+  }
+  // Put them all back to normal and the check should pass again.
+  buf[sizeof(buf) - 1] ^= 0x01;
+  EXPECT_TRUE(StunMessage::ValidateFingerprint(buf, sizeof(buf)));
+}
+
+TEST_F(StunTest, AddFingerprint) {
+  IceMessage msg;
+  rtc::ByteBuffer buf(
+      reinterpret_cast<const char*>(kRfc5769SampleRequestWithoutMI),
+      sizeof(kRfc5769SampleRequestWithoutMI));
+  EXPECT_TRUE(msg.Read(&buf));
+  EXPECT_TRUE(msg.AddFingerprint());
+
+  rtc::ByteBuffer buf1;
+  EXPECT_TRUE(msg.Write(&buf1));
+  EXPECT_TRUE(StunMessage::ValidateFingerprint(
+      reinterpret_cast<const char*>(buf1.Data()), buf1.Length()));
+}
+
+// Sample "GTURN" relay message.
+static const unsigned char kRelayMessage[] = {
+  0x00, 0x01, 0x00, 88,    // message header
+  0x21, 0x12, 0xA4, 0x42,  // magic cookie
+  '0', '1', '2', '3',      // transaction id
+  '4', '5', '6', '7',
+  '8', '9', 'a', 'b',
+  0x00, 0x01, 0x00, 8,     // mapped address
+  0x00, 0x01, 0x00, 13,
+  0x00, 0x00, 0x00, 17,
+  0x00, 0x06, 0x00, 12,    // username
+  'a', 'b', 'c', 'd',
+  'e', 'f', 'g', 'h',
+  'i', 'j', 'k', 'l',
+  0x00, 0x0d, 0x00, 4,     // lifetime
+  0x00, 0x00, 0x00, 11,
+  0x00, 0x0f, 0x00, 4,     // magic cookie
+  0x72, 0xc6, 0x4b, 0xc6,
+  0x00, 0x10, 0x00, 4,     // bandwidth
+  0x00, 0x00, 0x00, 6,
+  0x00, 0x11, 0x00, 8,     // destination address
+  0x00, 0x01, 0x00, 13,
+  0x00, 0x00, 0x00, 17,
+  0x00, 0x12, 0x00, 8,     // source address 2
+  0x00, 0x01, 0x00, 13,
+  0x00, 0x00, 0x00, 17,
+  0x00, 0x13, 0x00, 7,     // data
+  'a', 'b', 'c', 'd',
+  'e', 'f', 'g', 0         // DATA must be padded per rfc5766.
+};
+
+// Test that we can read the GTURN-specific fields.
+TEST_F(StunTest, ReadRelayMessage) {
+  RelayMessage msg, msg2;
+
+  const char* input = reinterpret_cast<const char*>(kRelayMessage);
+  size_t size = sizeof(kRelayMessage);
+  rtc::ByteBuffer buf(input, size);
+  EXPECT_TRUE(msg.Read(&buf));
+
+  EXPECT_EQ(STUN_BINDING_REQUEST, msg.type());
+  EXPECT_EQ(size - 20, msg.length());
+  EXPECT_EQ("0123456789ab", msg.transaction_id());
+
+  msg2.SetType(STUN_BINDING_REQUEST);
+  msg2.SetTransactionID("0123456789ab");
+
+  in_addr legacy_in_addr;
+  legacy_in_addr.s_addr = htonl(17U);
+  rtc::IPAddress legacy_ip(legacy_in_addr);
+
+  const StunAddressAttribute* addr = msg.GetAddress(STUN_ATTR_MAPPED_ADDRESS);
+  ASSERT_TRUE(addr != NULL);
+  EXPECT_EQ(1, addr->family());
+  EXPECT_EQ(13, addr->port());
+  EXPECT_EQ(legacy_ip, addr->ipaddr());
+
+  StunAddressAttribute* addr2 =
+      StunAttribute::CreateAddress(STUN_ATTR_MAPPED_ADDRESS);
+  addr2->SetPort(13);
+  addr2->SetIP(legacy_ip);
+  EXPECT_TRUE(msg2.AddAttribute(addr2));
+
+  const StunByteStringAttribute* bytes = msg.GetByteString(STUN_ATTR_USERNAME);
+  ASSERT_TRUE(bytes != NULL);
+  EXPECT_EQ(12U, bytes->length());
+  EXPECT_EQ("abcdefghijkl", bytes->GetString());
+
+  StunByteStringAttribute* bytes2 =
+  StunAttribute::CreateByteString(STUN_ATTR_USERNAME);
+  bytes2->CopyBytes("abcdefghijkl");
+  EXPECT_TRUE(msg2.AddAttribute(bytes2));
+
+  const StunUInt32Attribute* uval = msg.GetUInt32(STUN_ATTR_LIFETIME);
+  ASSERT_TRUE(uval != NULL);
+  EXPECT_EQ(11U, uval->value());
+
+  StunUInt32Attribute* uval2 = StunAttribute::CreateUInt32(STUN_ATTR_LIFETIME);
+  uval2->SetValue(11);
+  EXPECT_TRUE(msg2.AddAttribute(uval2));
+
+  bytes = msg.GetByteString(STUN_ATTR_MAGIC_COOKIE);
+  ASSERT_TRUE(bytes != NULL);
+  EXPECT_EQ(4U, bytes->length());
+  EXPECT_EQ(0,
+            memcmp(bytes->bytes(),
+                   TURN_MAGIC_COOKIE_VALUE,
+                   sizeof(TURN_MAGIC_COOKIE_VALUE)));
+
+  bytes2 = StunAttribute::CreateByteString(STUN_ATTR_MAGIC_COOKIE);
+  bytes2->CopyBytes(reinterpret_cast<const char*>(TURN_MAGIC_COOKIE_VALUE),
+                    sizeof(TURN_MAGIC_COOKIE_VALUE));
+  EXPECT_TRUE(msg2.AddAttribute(bytes2));
+
+  uval = msg.GetUInt32(STUN_ATTR_BANDWIDTH);
+  ASSERT_TRUE(uval != NULL);
+  EXPECT_EQ(6U, uval->value());
+
+  uval2 = StunAttribute::CreateUInt32(STUN_ATTR_BANDWIDTH);
+  uval2->SetValue(6);
+  EXPECT_TRUE(msg2.AddAttribute(uval2));
+
+  addr = msg.GetAddress(STUN_ATTR_DESTINATION_ADDRESS);
+  ASSERT_TRUE(addr != NULL);
+  EXPECT_EQ(1, addr->family());
+  EXPECT_EQ(13, addr->port());
+  EXPECT_EQ(legacy_ip, addr->ipaddr());
+
+  addr2 = StunAttribute::CreateAddress(STUN_ATTR_DESTINATION_ADDRESS);
+  addr2->SetPort(13);
+  addr2->SetIP(legacy_ip);
+  EXPECT_TRUE(msg2.AddAttribute(addr2));
+
+  addr = msg.GetAddress(STUN_ATTR_SOURCE_ADDRESS2);
+  ASSERT_TRUE(addr != NULL);
+  EXPECT_EQ(1, addr->family());
+  EXPECT_EQ(13, addr->port());
+  EXPECT_EQ(legacy_ip, addr->ipaddr());
+
+  addr2 = StunAttribute::CreateAddress(STUN_ATTR_SOURCE_ADDRESS2);
+  addr2->SetPort(13);
+  addr2->SetIP(legacy_ip);
+  EXPECT_TRUE(msg2.AddAttribute(addr2));
+
+  bytes = msg.GetByteString(STUN_ATTR_DATA);
+  ASSERT_TRUE(bytes != NULL);
+  EXPECT_EQ(7U, bytes->length());
+  EXPECT_EQ("abcdefg", bytes->GetString());
+
+  bytes2 = StunAttribute::CreateByteString(STUN_ATTR_DATA);
+  bytes2->CopyBytes("abcdefg");
+  EXPECT_TRUE(msg2.AddAttribute(bytes2));
+
+  rtc::ByteBuffer out;
+  EXPECT_TRUE(msg.Write(&out));
+  EXPECT_EQ(size, out.Length());
+  size_t len1 = out.Length();
+  std::string outstring;
+  out.ReadString(&outstring, len1);
+  EXPECT_EQ(0, memcmp(outstring.c_str(), input, len1));
+
+  rtc::ByteBuffer out2;
+  EXPECT_TRUE(msg2.Write(&out2));
+  EXPECT_EQ(size, out2.Length());
+  size_t len2 = out2.Length();
+  std::string outstring2;
+  out2.ReadString(&outstring2, len2);
+  EXPECT_EQ(0, memcmp(outstring2.c_str(), input, len2));
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/stunport.cc b/webrtc/p2p/base/stunport.cc
new file mode 100644
index 0000000..ec6232a
--- /dev/null
+++ b/webrtc/p2p/base/stunport.cc
@@ -0,0 +1,451 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/stunport.h"
+
+#include "webrtc/p2p/base/common.h"
+#include "webrtc/p2p/base/portallocator.h"
+#include "webrtc/p2p/base/stun.h"
+#include "webrtc/base/common.h"
+#include "webrtc/base/helpers.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/nethelpers.h"
+
+namespace cricket {
+
+// TODO: Move these to a common place (used in relayport too)
+const int KEEPALIVE_DELAY = 10 * 1000;  // 10 seconds - sort timeouts
+const int RETRY_DELAY = 50;             // 50ms, from ICE spec
+const int RETRY_TIMEOUT = 50 * 1000;    // ICE says 50 secs
+
+// Handles a binding request sent to the STUN server.
+class StunBindingRequest : public StunRequest {
+ public:
+  StunBindingRequest(UDPPort* port, bool keep_alive,
+                     const rtc::SocketAddress& addr)
+    : port_(port), keep_alive_(keep_alive), server_addr_(addr) {
+    start_time_ = rtc::Time();
+  }
+
+  virtual ~StunBindingRequest() {
+  }
+
+  const rtc::SocketAddress& server_addr() const { return server_addr_; }
+
+  virtual void Prepare(StunMessage* request) {
+    request->SetType(STUN_BINDING_REQUEST);
+  }
+
+  virtual void OnResponse(StunMessage* response) {
+    const StunAddressAttribute* addr_attr =
+        response->GetAddress(STUN_ATTR_MAPPED_ADDRESS);
+    if (!addr_attr) {
+      LOG(LS_ERROR) << "Binding response missing mapped address.";
+    } else if (addr_attr->family() != STUN_ADDRESS_IPV4 &&
+               addr_attr->family() != STUN_ADDRESS_IPV6) {
+      LOG(LS_ERROR) << "Binding address has bad family";
+    } else {
+      rtc::SocketAddress addr(addr_attr->ipaddr(), addr_attr->port());
+      port_->OnStunBindingRequestSucceeded(server_addr_, addr);
+    }
+
+    // We will do a keep-alive regardless of whether this request succeeds.
+    // This should have almost no impact on network usage.
+    if (keep_alive_) {
+      port_->requests_.SendDelayed(
+          new StunBindingRequest(port_, true, server_addr_),
+          port_->stun_keepalive_delay());
+    }
+  }
+
+  virtual void OnErrorResponse(StunMessage* response) {
+    const StunErrorCodeAttribute* attr = response->GetErrorCode();
+    if (!attr) {
+      LOG(LS_ERROR) << "Bad allocate response error code";
+    } else {
+      LOG(LS_ERROR) << "Binding error response:"
+                 << " class=" << attr->eclass()
+                 << " number=" << attr->number()
+                 << " reason='" << attr->reason() << "'";
+    }
+
+    port_->OnStunBindingOrResolveRequestFailed(server_addr_);
+
+    if (keep_alive_
+        && (rtc::TimeSince(start_time_) <= RETRY_TIMEOUT)) {
+      port_->requests_.SendDelayed(
+          new StunBindingRequest(port_, true, server_addr_),
+          port_->stun_keepalive_delay());
+    }
+  }
+
+  virtual void OnTimeout() {
+    LOG(LS_ERROR) << "Binding request timed out from "
+      << port_->GetLocalAddress().ToSensitiveString()
+      << " (" << port_->Network()->name() << ")";
+
+    port_->OnStunBindingOrResolveRequestFailed(server_addr_);
+
+    if (keep_alive_
+        && (rtc::TimeSince(start_time_) <= RETRY_TIMEOUT)) {
+      port_->requests_.SendDelayed(
+          new StunBindingRequest(port_, true, server_addr_),
+          RETRY_DELAY);
+    }
+  }
+
+ private:
+  UDPPort* port_;
+  bool keep_alive_;
+  const rtc::SocketAddress server_addr_;
+  uint32 start_time_;
+};
+
+UDPPort::AddressResolver::AddressResolver(
+    rtc::PacketSocketFactory* factory)
+    : socket_factory_(factory) {}
+
+UDPPort::AddressResolver::~AddressResolver() {
+  for (ResolverMap::iterator it = resolvers_.begin();
+       it != resolvers_.end(); ++it) {
+    it->second->Destroy(true);
+  }
+}
+
+void UDPPort::AddressResolver::Resolve(
+    const rtc::SocketAddress& address) {
+  if (resolvers_.find(address) != resolvers_.end())
+    return;
+
+  rtc::AsyncResolverInterface* resolver =
+      socket_factory_->CreateAsyncResolver();
+  resolvers_.insert(
+      std::pair<rtc::SocketAddress, rtc::AsyncResolverInterface*>(
+          address, resolver));
+
+  resolver->SignalDone.connect(this,
+                               &UDPPort::AddressResolver::OnResolveResult);
+
+  resolver->Start(address);
+}
+
+bool UDPPort::AddressResolver::GetResolvedAddress(
+    const rtc::SocketAddress& input,
+    int family,
+    rtc::SocketAddress* output) const {
+  ResolverMap::const_iterator it = resolvers_.find(input);
+  if (it == resolvers_.end())
+    return false;
+
+  return it->second->GetResolvedAddress(family, output);
+}
+
+void UDPPort::AddressResolver::OnResolveResult(
+    rtc::AsyncResolverInterface* resolver) {
+  for (ResolverMap::iterator it = resolvers_.begin();
+       it != resolvers_.end(); ++it) {
+    if (it->second == resolver) {
+      SignalDone(it->first, resolver->GetError());
+      return;
+    }
+  }
+}
+
+UDPPort::UDPPort(rtc::Thread* thread,
+                 rtc::PacketSocketFactory* factory,
+                 rtc::Network* network,
+                 rtc::AsyncPacketSocket* socket,
+                 const std::string& username, const std::string& password)
+    : Port(thread, factory, network, socket->GetLocalAddress().ipaddr(),
+           username, password),
+      requests_(thread),
+      socket_(socket),
+      error_(0),
+      ready_(false),
+      stun_keepalive_delay_(KEEPALIVE_DELAY) {
+}
+
+UDPPort::UDPPort(rtc::Thread* thread,
+                 rtc::PacketSocketFactory* factory,
+                 rtc::Network* network,
+                 const rtc::IPAddress& ip, int min_port, int max_port,
+                 const std::string& username, const std::string& password)
+    : Port(thread, LOCAL_PORT_TYPE, factory, network, ip, min_port, max_port,
+           username, password),
+      requests_(thread),
+      socket_(NULL),
+      error_(0),
+      ready_(false),
+      stun_keepalive_delay_(KEEPALIVE_DELAY) {
+}
+
+bool UDPPort::Init() {
+  if (!SharedSocket()) {
+    ASSERT(socket_ == NULL);
+    socket_ = socket_factory()->CreateUdpSocket(
+        rtc::SocketAddress(ip(), 0), min_port(), max_port());
+    if (!socket_) {
+      LOG_J(LS_WARNING, this) << "UDP socket creation failed";
+      return false;
+    }
+    socket_->SignalReadPacket.connect(this, &UDPPort::OnReadPacket);
+  }
+  socket_->SignalReadyToSend.connect(this, &UDPPort::OnReadyToSend);
+  socket_->SignalAddressReady.connect(this, &UDPPort::OnLocalAddressReady);
+  requests_.SignalSendPacket.connect(this, &UDPPort::OnSendPacket);
+  return true;
+}
+
+UDPPort::~UDPPort() {
+  if (!SharedSocket())
+    delete socket_;
+}
+
+void UDPPort::PrepareAddress() {
+  ASSERT(requests_.empty());
+  if (socket_->GetState() == rtc::AsyncPacketSocket::STATE_BOUND) {
+    OnLocalAddressReady(socket_, socket_->GetLocalAddress());
+  }
+}
+
+void UDPPort::MaybePrepareStunCandidate() {
+  // Sending binding request to the STUN server if address is available to
+  // prepare STUN candidate.
+  if (!server_addresses_.empty()) {
+    SendStunBindingRequests();
+  } else {
+    // Port is done allocating candidates.
+    MaybeSetPortCompleteOrError();
+  }
+}
+
+Connection* UDPPort::CreateConnection(const Candidate& address,
+                                       CandidateOrigin origin) {
+  if (address.protocol() != "udp")
+    return NULL;
+
+  if (!IsCompatibleAddress(address.address())) {
+    return NULL;
+  }
+
+  if (SharedSocket() && Candidates()[0].type() != LOCAL_PORT_TYPE) {
+    ASSERT(false);
+    return NULL;
+  }
+
+  Connection* conn = new ProxyConnection(this, 0, address);
+  AddConnection(conn);
+  return conn;
+}
+
+int UDPPort::SendTo(const void* data, size_t size,
+                    const rtc::SocketAddress& addr,
+                    const rtc::PacketOptions& options,
+                    bool payload) {
+  int sent = socket_->SendTo(data, size, addr, options);
+  if (sent < 0) {
+    error_ = socket_->GetError();
+    LOG_J(LS_ERROR, this) << "UDP send of " << size
+                          << " bytes failed with error " << error_;
+  }
+  return sent;
+}
+
+int UDPPort::SetOption(rtc::Socket::Option opt, int value) {
+  return socket_->SetOption(opt, value);
+}
+
+int UDPPort::GetOption(rtc::Socket::Option opt, int* value) {
+  return socket_->GetOption(opt, value);
+}
+
+int UDPPort::GetError() {
+  return error_;
+}
+
+void UDPPort::OnLocalAddressReady(rtc::AsyncPacketSocket* socket,
+                                  const rtc::SocketAddress& address) {
+  AddAddress(address, address, rtc::SocketAddress(),
+             UDP_PROTOCOL_NAME, "", LOCAL_PORT_TYPE,
+             ICE_TYPE_PREFERENCE_HOST, 0, false);
+  MaybePrepareStunCandidate();
+}
+
+void UDPPort::OnReadPacket(
+  rtc::AsyncPacketSocket* socket, const char* data, size_t size,
+  const rtc::SocketAddress& remote_addr,
+  const rtc::PacketTime& packet_time) {
+  ASSERT(socket == socket_);
+  ASSERT(!remote_addr.IsUnresolved());
+
+  // Look for a response from the STUN server.
+  // Even if the response doesn't match one of our outstanding requests, we
+  // will eat it because it might be a response to a retransmitted packet, and
+  // we already cleared the request when we got the first response.
+  if (server_addresses_.find(remote_addr) != server_addresses_.end()) {
+    requests_.CheckResponse(data, size);
+    return;
+  }
+
+  if (Connection* conn = GetConnection(remote_addr)) {
+    conn->OnReadPacket(data, size, packet_time);
+  } else {
+    Port::OnReadPacket(data, size, remote_addr, PROTO_UDP);
+  }
+}
+
+void UDPPort::OnReadyToSend(rtc::AsyncPacketSocket* socket) {
+  Port::OnReadyToSend();
+}
+
+void UDPPort::SendStunBindingRequests() {
+  // We will keep pinging the stun server to make sure our NAT pin-hole stays
+  // open during the call.
+  ASSERT(requests_.empty());
+
+  for (ServerAddresses::const_iterator it = server_addresses_.begin();
+       it != server_addresses_.end(); ++it) {
+    SendStunBindingRequest(*it);
+  }
+}
+
+void UDPPort::ResolveStunAddress(const rtc::SocketAddress& stun_addr) {
+  if (!resolver_) {
+    resolver_.reset(new AddressResolver(socket_factory()));
+    resolver_->SignalDone.connect(this, &UDPPort::OnResolveResult);
+  }
+
+  resolver_->Resolve(stun_addr);
+}
+
+void UDPPort::OnResolveResult(const rtc::SocketAddress& input,
+                              int error) {
+  ASSERT(resolver_.get() != NULL);
+
+  rtc::SocketAddress resolved;
+  if (error != 0 ||
+      !resolver_->GetResolvedAddress(input, ip().family(), &resolved))  {
+    LOG_J(LS_WARNING, this) << "StunPort: stun host lookup received error "
+                            << error;
+    OnStunBindingOrResolveRequestFailed(input);
+    return;
+  }
+
+  server_addresses_.erase(input);
+
+  if (server_addresses_.find(resolved) == server_addresses_.end()) {
+    server_addresses_.insert(resolved);
+    SendStunBindingRequest(resolved);
+  }
+}
+
+void UDPPort::SendStunBindingRequest(
+    const rtc::SocketAddress& stun_addr) {
+  if (stun_addr.IsUnresolved()) {
+    ResolveStunAddress(stun_addr);
+
+  } else if (socket_->GetState() == rtc::AsyncPacketSocket::STATE_BOUND) {
+    // Check if |server_addr_| is compatible with the port's ip.
+    if (IsCompatibleAddress(stun_addr)) {
+      requests_.Send(new StunBindingRequest(this, true, stun_addr));
+    } else {
+      // Since we can't send stun messages to the server, we should mark this
+      // port ready.
+      LOG(LS_WARNING) << "STUN server address is incompatible.";
+      OnStunBindingOrResolveRequestFailed(stun_addr);
+    }
+  }
+}
+
+void UDPPort::OnStunBindingRequestSucceeded(
+    const rtc::SocketAddress& stun_server_addr,
+    const rtc::SocketAddress& stun_reflected_addr) {
+  if (bind_request_succeeded_servers_.find(stun_server_addr) !=
+          bind_request_succeeded_servers_.end()) {
+    return;
+  }
+  bind_request_succeeded_servers_.insert(stun_server_addr);
+
+  // If socket is shared and |stun_reflected_addr| is equal to local socket
+  // address, or if the same address has been added by another STUN server,
+  // then discarding the stun address.
+  // For STUN, related address is the local socket address.
+  if ((!SharedSocket() || stun_reflected_addr != socket_->GetLocalAddress()) &&
+      !HasCandidateWithAddress(stun_reflected_addr)) {
+
+    rtc::SocketAddress related_address = socket_->GetLocalAddress();
+    if (!(candidate_filter() & CF_HOST)) {
+      // If candidate filter doesn't have CF_HOST specified, empty raddr to
+      // avoid local address leakage.
+      related_address = rtc::EmptySocketAddressWithFamily(
+          related_address.family());
+    }
+
+    AddAddress(stun_reflected_addr, socket_->GetLocalAddress(),
+               related_address, UDP_PROTOCOL_NAME, "",
+               STUN_PORT_TYPE, ICE_TYPE_PREFERENCE_SRFLX, 0, false);
+  }
+  MaybeSetPortCompleteOrError();
+}
+
+void UDPPort::OnStunBindingOrResolveRequestFailed(
+    const rtc::SocketAddress& stun_server_addr) {
+  if (bind_request_failed_servers_.find(stun_server_addr) !=
+          bind_request_failed_servers_.end()) {
+    return;
+  }
+  bind_request_failed_servers_.insert(stun_server_addr);
+  MaybeSetPortCompleteOrError();
+}
+
+void UDPPort::MaybeSetPortCompleteOrError() {
+  if (ready_)
+    return;
+
+  // Do not set port ready if we are still waiting for bind responses.
+  const size_t servers_done_bind_request = bind_request_failed_servers_.size() +
+      bind_request_succeeded_servers_.size();
+  if (server_addresses_.size() != servers_done_bind_request) {
+    return;
+  }
+
+  // Setting ready status.
+  ready_ = true;
+
+  // The port is "completed" if there is no stun server provided, or the bind
+  // request succeeded for any stun server, or the socket is shared.
+  if (server_addresses_.empty() ||
+      bind_request_succeeded_servers_.size() > 0 ||
+      SharedSocket()) {
+    SignalPortComplete(this);
+  } else {
+    SignalPortError(this);
+  }
+}
+
+// TODO: merge this with SendTo above.
+void UDPPort::OnSendPacket(const void* data, size_t size, StunRequest* req) {
+  StunBindingRequest* sreq = static_cast<StunBindingRequest*>(req);
+  rtc::PacketOptions options(DefaultDscpValue());
+  if (socket_->SendTo(data, size, sreq->server_addr(), options) < 0)
+    PLOG(LERROR, socket_->GetError()) << "sendto";
+}
+
+bool UDPPort::HasCandidateWithAddress(const rtc::SocketAddress& addr) const {
+  const std::vector<Candidate>& existing_candidates = Candidates();
+  std::vector<Candidate>::const_iterator it = existing_candidates.begin();
+  for (; it != existing_candidates.end(); ++it) {
+    if (it->address() == addr)
+      return true;
+  }
+  return false;
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/stunport.h b/webrtc/p2p/base/stunport.h
new file mode 100644
index 0000000..eda7bb9
--- /dev/null
+++ b/webrtc/p2p/base/stunport.h
@@ -0,0 +1,238 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_STUNPORT_H_
+#define WEBRTC_P2P_BASE_STUNPORT_H_
+
+#include <string>
+
+#include "webrtc/p2p/base/port.h"
+#include "webrtc/p2p/base/stunrequest.h"
+#include "webrtc/base/asyncpacketsocket.h"
+
+// TODO(mallinath) - Rename stunport.cc|h to udpport.cc|h.
+namespace rtc {
+class AsyncResolver;
+class SignalThread;
+}
+
+namespace cricket {
+
+// Communicates using the address on the outside of a NAT.
+class UDPPort : public Port {
+ public:
+  static UDPPort* Create(rtc::Thread* thread,
+                         rtc::PacketSocketFactory* factory,
+                         rtc::Network* network,
+                         rtc::AsyncPacketSocket* socket,
+                         const std::string& username,
+                         const std::string& password) {
+    UDPPort* port = new UDPPort(thread, factory, network, socket,
+                                username, password);
+    if (!port->Init()) {
+      delete port;
+      port = NULL;
+    }
+    return port;
+  }
+
+  static UDPPort* Create(rtc::Thread* thread,
+                         rtc::PacketSocketFactory* factory,
+                         rtc::Network* network,
+                         const rtc::IPAddress& ip,
+                         int min_port, int max_port,
+                         const std::string& username,
+                         const std::string& password) {
+    UDPPort* port = new UDPPort(thread, factory, network,
+                                ip, min_port, max_port,
+                                username, password);
+    if (!port->Init()) {
+      delete port;
+      port = NULL;
+    }
+    return port;
+  }
+  virtual ~UDPPort();
+
+  rtc::SocketAddress GetLocalAddress() const {
+    return socket_->GetLocalAddress();
+  }
+
+  const ServerAddresses& server_addresses() const {
+    return server_addresses_;
+  }
+  void
+  set_server_addresses(const ServerAddresses& addresses) {
+    server_addresses_ = addresses;
+  }
+
+  virtual void PrepareAddress();
+
+  virtual Connection* CreateConnection(const Candidate& address,
+                                       CandidateOrigin origin);
+  virtual int SetOption(rtc::Socket::Option opt, int value);
+  virtual int GetOption(rtc::Socket::Option opt, int* value);
+  virtual int GetError();
+
+  virtual bool HandleIncomingPacket(
+      rtc::AsyncPacketSocket* socket, const char* data, size_t size,
+      const rtc::SocketAddress& remote_addr,
+      const rtc::PacketTime& packet_time) {
+    // All packets given to UDP port will be consumed.
+    OnReadPacket(socket, data, size, remote_addr, packet_time);
+    return true;
+  }
+
+  void set_stun_keepalive_delay(int delay) {
+    stun_keepalive_delay_ = delay;
+  }
+  int stun_keepalive_delay() const {
+    return stun_keepalive_delay_;
+  }
+
+ protected:
+  UDPPort(rtc::Thread* thread, rtc::PacketSocketFactory* factory,
+          rtc::Network* network, const rtc::IPAddress& ip,
+          int min_port, int max_port,
+          const std::string& username, const std::string& password);
+
+  UDPPort(rtc::Thread* thread, rtc::PacketSocketFactory* factory,
+          rtc::Network* network, rtc::AsyncPacketSocket* socket,
+          const std::string& username, const std::string& password);
+
+  bool Init();
+
+  virtual int SendTo(const void* data, size_t size,
+                     const rtc::SocketAddress& addr,
+                     const rtc::PacketOptions& options,
+                     bool payload);
+
+  void OnLocalAddressReady(rtc::AsyncPacketSocket* socket,
+                           const rtc::SocketAddress& address);
+  void OnReadPacket(rtc::AsyncPacketSocket* socket,
+                    const char* data, size_t size,
+                    const rtc::SocketAddress& remote_addr,
+                    const rtc::PacketTime& packet_time);
+
+  void OnReadyToSend(rtc::AsyncPacketSocket* socket);
+
+  // This method will send STUN binding request if STUN server address is set.
+  void MaybePrepareStunCandidate();
+
+  void SendStunBindingRequests();
+
+ private:
+  // A helper class which can be called repeatedly to resolve multiple
+  // addresses, as opposed to rtc::AsyncResolverInterface, which can only
+  // resolve one address per instance.
+  class AddressResolver : public sigslot::has_slots<> {
+   public:
+    explicit AddressResolver(rtc::PacketSocketFactory* factory);
+    ~AddressResolver();
+
+    void Resolve(const rtc::SocketAddress& address);
+    bool GetResolvedAddress(const rtc::SocketAddress& input,
+                            int family,
+                            rtc::SocketAddress* output) const;
+
+    // The signal is sent when resolving the specified address is finished. The
+    // first argument is the input address, the second argument is the error
+    // or 0 if it succeeded.
+    sigslot::signal2<const rtc::SocketAddress&, int> SignalDone;
+
+   private:
+    typedef std::map<rtc::SocketAddress,
+                     rtc::AsyncResolverInterface*> ResolverMap;
+
+    void OnResolveResult(rtc::AsyncResolverInterface* resolver);
+
+    rtc::PacketSocketFactory* socket_factory_;
+    ResolverMap resolvers_;
+  };
+
+  // DNS resolution of the STUN server.
+  void ResolveStunAddress(const rtc::SocketAddress& stun_addr);
+  void OnResolveResult(const rtc::SocketAddress& input, int error);
+
+  void SendStunBindingRequest(const rtc::SocketAddress& stun_addr);
+
+  // Below methods handles binding request responses.
+  void OnStunBindingRequestSucceeded(
+      const rtc::SocketAddress& stun_server_addr,
+      const rtc::SocketAddress& stun_reflected_addr);
+  void OnStunBindingOrResolveRequestFailed(
+      const rtc::SocketAddress& stun_server_addr);
+
+  // Sends STUN requests to the server.
+  void OnSendPacket(const void* data, size_t size, StunRequest* req);
+
+  // TODO(mallinaht) - Move this up to cricket::Port when SignalAddressReady is
+  // changed to SignalPortReady.
+  void MaybeSetPortCompleteOrError();
+
+  bool HasCandidateWithAddress(const rtc::SocketAddress& addr) const;
+
+  ServerAddresses server_addresses_;
+  ServerAddresses bind_request_succeeded_servers_;
+  ServerAddresses bind_request_failed_servers_;
+  StunRequestManager requests_;
+  rtc::AsyncPacketSocket* socket_;
+  int error_;
+  rtc::scoped_ptr<AddressResolver> resolver_;
+  bool ready_;
+  int stun_keepalive_delay_;
+
+  friend class StunBindingRequest;
+};
+
+class StunPort : public UDPPort {
+ public:
+  static StunPort* Create(
+      rtc::Thread* thread,
+      rtc::PacketSocketFactory* factory,
+      rtc::Network* network,
+      const rtc::IPAddress& ip,
+      int min_port, int max_port,
+      const std::string& username,
+      const std::string& password,
+      const ServerAddresses& servers) {
+    StunPort* port = new StunPort(thread, factory, network,
+                                  ip, min_port, max_port,
+                                  username, password, servers);
+    if (!port->Init()) {
+      delete port;
+      port = NULL;
+    }
+    return port;
+  }
+
+  virtual ~StunPort() {}
+
+  virtual void PrepareAddress() {
+    SendStunBindingRequests();
+  }
+
+ protected:
+  StunPort(rtc::Thread* thread, rtc::PacketSocketFactory* factory,
+           rtc::Network* network, const rtc::IPAddress& ip,
+           int min_port, int max_port,
+           const std::string& username, const std::string& password,
+           const ServerAddresses& servers)
+     : UDPPort(thread, factory, network, ip, min_port, max_port, username,
+               password) {
+    // UDPPort will set these to local udp, updating these to STUN.
+    set_type(STUN_PORT_TYPE);
+    set_server_addresses(servers);
+  }
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_STUNPORT_H_
diff --git a/webrtc/p2p/base/stunport_unittest.cc b/webrtc/p2p/base/stunport_unittest.cc
new file mode 100644
index 0000000..81b6808
--- /dev/null
+++ b/webrtc/p2p/base/stunport_unittest.cc
@@ -0,0 +1,283 @@
+/*
+ *  Copyright 2009 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/basicpacketsocketfactory.h"
+#include "webrtc/p2p/base/stunport.h"
+#include "webrtc/p2p/base/teststunserver.h"
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/helpers.h"
+#include "webrtc/base/physicalsocketserver.h"
+#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/socketaddress.h"
+#include "webrtc/base/ssladapter.h"
+#include "webrtc/base/virtualsocketserver.h"
+
+using cricket::ServerAddresses;
+using rtc::SocketAddress;
+
+static const SocketAddress kLocalAddr("127.0.0.1", 0);
+static const SocketAddress kStunAddr1("127.0.0.1", 5000);
+static const SocketAddress kStunAddr2("127.0.0.1", 4000);
+static const SocketAddress kBadAddr("0.0.0.1", 5000);
+static const SocketAddress kStunHostnameAddr("localhost", 5000);
+static const SocketAddress kBadHostnameAddr("not-a-real-hostname", 5000);
+static const int kTimeoutMs = 10000;
+// stun prio = 100 << 24 | 30 (IPV4) << 8 | 256 - 0
+static const uint32 kStunCandidatePriority = 1677729535;
+
+// Tests connecting a StunPort to a fake STUN server (cricket::StunServer)
+// TODO: Use a VirtualSocketServer here. We have to use a
+// PhysicalSocketServer right now since DNS is not part of SocketServer yet.
+class StunPortTest : public testing::Test,
+                     public sigslot::has_slots<> {
+ public:
+  StunPortTest()
+      : pss_(new rtc::PhysicalSocketServer),
+        ss_(new rtc::VirtualSocketServer(pss_.get())),
+        ss_scope_(ss_.get()),
+        network_("unittest", "unittest", rtc::IPAddress(INADDR_ANY), 32),
+        socket_factory_(rtc::Thread::Current()),
+        stun_server_1_(cricket::TestStunServer::Create(
+          rtc::Thread::Current(), kStunAddr1)),
+        stun_server_2_(cricket::TestStunServer::Create(
+          rtc::Thread::Current(), kStunAddr2)),
+        done_(false), error_(false), stun_keepalive_delay_(0) {
+  }
+
+  const cricket::Port* port() const { return stun_port_.get(); }
+  bool done() const { return done_; }
+  bool error() const { return error_; }
+
+  void CreateStunPort(const rtc::SocketAddress& server_addr) {
+    ServerAddresses stun_servers;
+    stun_servers.insert(server_addr);
+    CreateStunPort(stun_servers);
+  }
+
+  void CreateStunPort(const ServerAddresses& stun_servers) {
+    stun_port_.reset(cricket::StunPort::Create(
+        rtc::Thread::Current(), &socket_factory_, &network_,
+        kLocalAddr.ipaddr(), 0, 0, rtc::CreateRandomString(16),
+        rtc::CreateRandomString(22), stun_servers));
+    stun_port_->set_stun_keepalive_delay(stun_keepalive_delay_);
+    stun_port_->SignalPortComplete.connect(this,
+        &StunPortTest::OnPortComplete);
+    stun_port_->SignalPortError.connect(this,
+        &StunPortTest::OnPortError);
+  }
+
+  void CreateSharedStunPort(const rtc::SocketAddress& server_addr) {
+    socket_.reset(socket_factory_.CreateUdpSocket(
+        rtc::SocketAddress(kLocalAddr.ipaddr(), 0), 0, 0));
+    ASSERT_TRUE(socket_ != NULL);
+    socket_->SignalReadPacket.connect(this, &StunPortTest::OnReadPacket);
+    stun_port_.reset(cricket::UDPPort::Create(
+        rtc::Thread::Current(), &socket_factory_,
+        &network_, socket_.get(),
+        rtc::CreateRandomString(16), rtc::CreateRandomString(22)));
+    ASSERT_TRUE(stun_port_ != NULL);
+    ServerAddresses stun_servers;
+    stun_servers.insert(server_addr);
+    stun_port_->set_server_addresses(stun_servers);
+    stun_port_->SignalPortComplete.connect(this,
+        &StunPortTest::OnPortComplete);
+    stun_port_->SignalPortError.connect(this,
+        &StunPortTest::OnPortError);
+  }
+
+  void PrepareAddress() {
+    stun_port_->PrepareAddress();
+  }
+
+  void OnReadPacket(rtc::AsyncPacketSocket* socket, const char* data,
+                    size_t size, const rtc::SocketAddress& remote_addr,
+                    const rtc::PacketTime& packet_time) {
+    stun_port_->HandleIncomingPacket(
+        socket, data, size, remote_addr, rtc::PacketTime());
+  }
+
+  void SendData(const char* data, size_t len) {
+    stun_port_->HandleIncomingPacket(
+        socket_.get(), data, len, rtc::SocketAddress("22.22.22.22", 0),
+        rtc::PacketTime());
+  }
+
+ protected:
+  static void SetUpTestCase() {
+    // Ensure the RNG is inited.
+    rtc::InitRandom(NULL, 0);
+
+  }
+
+  void OnPortComplete(cricket::Port* port) {
+    ASSERT_FALSE(done_);
+    done_ = true;
+    error_ = false;
+  }
+  void OnPortError(cricket::Port* port) {
+    done_ = true;
+    error_ = true;
+  }
+  void SetKeepaliveDelay(int delay) {
+    stun_keepalive_delay_ = delay;
+  }
+
+  cricket::TestStunServer* stun_server_1() {
+    return stun_server_1_.get();
+  }
+  cricket::TestStunServer* stun_server_2() {
+    return stun_server_2_.get();
+  }
+
+ private:
+  rtc::scoped_ptr<rtc::PhysicalSocketServer> pss_;
+  rtc::scoped_ptr<rtc::VirtualSocketServer> ss_;
+  rtc::SocketServerScope ss_scope_;
+  rtc::Network network_;
+  rtc::BasicPacketSocketFactory socket_factory_;
+  rtc::scoped_ptr<cricket::UDPPort> stun_port_;
+  rtc::scoped_ptr<cricket::TestStunServer> stun_server_1_;
+  rtc::scoped_ptr<cricket::TestStunServer> stun_server_2_;
+  rtc::scoped_ptr<rtc::AsyncPacketSocket> socket_;
+  bool done_;
+  bool error_;
+  int stun_keepalive_delay_;
+};
+
+// Test that we can create a STUN port
+TEST_F(StunPortTest, TestBasic) {
+  CreateStunPort(kStunAddr1);
+  EXPECT_EQ("stun", port()->Type());
+  EXPECT_EQ(0U, port()->Candidates().size());
+}
+
+// Test that we can get an address from a STUN server.
+TEST_F(StunPortTest, TestPrepareAddress) {
+  CreateStunPort(kStunAddr1);
+  PrepareAddress();
+  EXPECT_TRUE_WAIT(done(), kTimeoutMs);
+  ASSERT_EQ(1U, port()->Candidates().size());
+  EXPECT_TRUE(kLocalAddr.EqualIPs(port()->Candidates()[0].address()));
+
+  // TODO: Add IPv6 tests here, once either physicalsocketserver supports
+  // IPv6, or this test is changed to use VirtualSocketServer.
+}
+
+// Test that we fail properly if we can't get an address.
+TEST_F(StunPortTest, TestPrepareAddressFail) {
+  CreateStunPort(kBadAddr);
+  PrepareAddress();
+  EXPECT_TRUE_WAIT(done(), kTimeoutMs);
+  EXPECT_TRUE(error());
+  EXPECT_EQ(0U, port()->Candidates().size());
+}
+
+// Test that we can get an address from a STUN server specified by a hostname.
+TEST_F(StunPortTest, TestPrepareAddressHostname) {
+  CreateStunPort(kStunHostnameAddr);
+  PrepareAddress();
+  EXPECT_TRUE_WAIT(done(), kTimeoutMs);
+  ASSERT_EQ(1U, port()->Candidates().size());
+  EXPECT_TRUE(kLocalAddr.EqualIPs(port()->Candidates()[0].address()));
+  EXPECT_EQ(kStunCandidatePriority, port()->Candidates()[0].priority());
+}
+
+// Test that we handle hostname lookup failures properly.
+TEST_F(StunPortTest, TestPrepareAddressHostnameFail) {
+  CreateStunPort(kBadHostnameAddr);
+  PrepareAddress();
+  EXPECT_TRUE_WAIT(done(), kTimeoutMs);
+  EXPECT_TRUE(error());
+  EXPECT_EQ(0U, port()->Candidates().size());
+}
+
+// This test verifies keepalive response messages don't result in
+// additional candidate generation.
+TEST_F(StunPortTest, TestKeepAliveResponse) {
+  SetKeepaliveDelay(500);  // 500ms of keepalive delay.
+  CreateStunPort(kStunHostnameAddr);
+  PrepareAddress();
+  EXPECT_TRUE_WAIT(done(), kTimeoutMs);
+  ASSERT_EQ(1U, port()->Candidates().size());
+  EXPECT_TRUE(kLocalAddr.EqualIPs(port()->Candidates()[0].address()));
+  // Waiting for 1 seond, which will allow us to process
+  // response for keepalive binding request. 500 ms is the keepalive delay.
+  rtc::Thread::Current()->ProcessMessages(1000);
+  ASSERT_EQ(1U, port()->Candidates().size());
+}
+
+// Test that a local candidate can be generated using a shared socket.
+TEST_F(StunPortTest, TestSharedSocketPrepareAddress) {
+  CreateSharedStunPort(kStunAddr1);
+  PrepareAddress();
+  EXPECT_TRUE_WAIT(done(), kTimeoutMs);
+  ASSERT_EQ(1U, port()->Candidates().size());
+  EXPECT_TRUE(kLocalAddr.EqualIPs(port()->Candidates()[0].address()));
+}
+
+// Test that we still a get a local candidate with invalid stun server hostname.
+// Also verifing that UDPPort can receive packets when stun address can't be
+// resolved.
+TEST_F(StunPortTest, TestSharedSocketPrepareAddressInvalidHostname) {
+  CreateSharedStunPort(kBadHostnameAddr);
+  PrepareAddress();
+  EXPECT_TRUE_WAIT(done(), kTimeoutMs);
+  ASSERT_EQ(1U, port()->Candidates().size());
+  EXPECT_TRUE(kLocalAddr.EqualIPs(port()->Candidates()[0].address()));
+
+  // Send data to port after it's ready. This is to make sure, UDP port can
+  // handle data with unresolved stun server address.
+  std::string data = "some random data, sending to cricket::Port.";
+  SendData(data.c_str(), data.length());
+  // No crash is success.
+}
+
+// Test that the same address is added only once if two STUN servers are in use.
+TEST_F(StunPortTest, TestNoDuplicatedAddressWithTwoStunServers) {
+  ServerAddresses stun_servers;
+  stun_servers.insert(kStunAddr1);
+  stun_servers.insert(kStunAddr2);
+  CreateStunPort(stun_servers);
+  EXPECT_EQ("stun", port()->Type());
+  PrepareAddress();
+  EXPECT_TRUE_WAIT(done(), kTimeoutMs);
+  EXPECT_EQ(1U, port()->Candidates().size());
+}
+
+// Test that candidates can be allocated for multiple STUN servers, one of which
+// is not reachable.
+TEST_F(StunPortTest, TestMultipleStunServersWithBadServer) {
+  ServerAddresses stun_servers;
+  stun_servers.insert(kStunAddr1);
+  stun_servers.insert(kBadAddr);
+  CreateStunPort(stun_servers);
+  EXPECT_EQ("stun", port()->Type());
+  PrepareAddress();
+  EXPECT_TRUE_WAIT(done(), kTimeoutMs);
+  EXPECT_EQ(1U, port()->Candidates().size());
+}
+
+// Test that two candidates are allocated if the two STUN servers return
+// different mapped addresses.
+TEST_F(StunPortTest, TestTwoCandidatesWithTwoStunServersAcrossNat) {
+  const SocketAddress kStunMappedAddr1("77.77.77.77", 0);
+  const SocketAddress kStunMappedAddr2("88.77.77.77", 0);
+  stun_server_1()->set_fake_stun_addr(kStunMappedAddr1);
+  stun_server_2()->set_fake_stun_addr(kStunMappedAddr2);
+
+  ServerAddresses stun_servers;
+  stun_servers.insert(kStunAddr1);
+  stun_servers.insert(kStunAddr2);
+  CreateStunPort(stun_servers);
+  EXPECT_EQ("stun", port()->Type());
+  PrepareAddress();
+  EXPECT_TRUE_WAIT(done(), kTimeoutMs);
+  EXPECT_EQ(2U, port()->Candidates().size());
+}
diff --git a/webrtc/p2p/base/stunrequest.cc b/webrtc/p2p/base/stunrequest.cc
new file mode 100644
index 0000000..65eb027
--- /dev/null
+++ b/webrtc/p2p/base/stunrequest.cc
@@ -0,0 +1,193 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/stunrequest.h"
+
+#include "webrtc/base/common.h"
+#include "webrtc/base/helpers.h"
+#include "webrtc/base/logging.h"
+
+namespace cricket {
+
+const uint32 MSG_STUN_SEND = 1;
+
+const int MAX_SENDS = 9;
+const int DELAY_UNIT = 100;  // 100 milliseconds
+const int DELAY_MAX_FACTOR = 16;
+
+StunRequestManager::StunRequestManager(rtc::Thread* thread)
+    : thread_(thread) {
+}
+
+StunRequestManager::~StunRequestManager() {
+  while (requests_.begin() != requests_.end()) {
+    StunRequest *request = requests_.begin()->second;
+    requests_.erase(requests_.begin());
+    delete request;
+  }
+}
+
+void StunRequestManager::Send(StunRequest* request) {
+  SendDelayed(request, 0);
+}
+
+void StunRequestManager::SendDelayed(StunRequest* request, int delay) {
+  request->set_manager(this);
+  ASSERT(requests_.find(request->id()) == requests_.end());
+  request->Construct();
+  requests_[request->id()] = request;
+  thread_->PostDelayed(delay, request, MSG_STUN_SEND, NULL);
+}
+
+void StunRequestManager::Remove(StunRequest* request) {
+  ASSERT(request->manager() == this);
+  RequestMap::iterator iter = requests_.find(request->id());
+  if (iter != requests_.end()) {
+    ASSERT(iter->second == request);
+    requests_.erase(iter);
+    thread_->Clear(request);
+  }
+}
+
+void StunRequestManager::Clear() {
+  std::vector<StunRequest*> requests;
+  for (RequestMap::iterator i = requests_.begin(); i != requests_.end(); ++i)
+    requests.push_back(i->second);
+
+  for (uint32 i = 0; i < requests.size(); ++i) {
+    // StunRequest destructor calls Remove() which deletes requests
+    // from |requests_|.
+    delete requests[i];
+  }
+}
+
+bool StunRequestManager::CheckResponse(StunMessage* msg) {
+  RequestMap::iterator iter = requests_.find(msg->transaction_id());
+  if (iter == requests_.end())
+    return false;
+
+  StunRequest* request = iter->second;
+  if (msg->type() == GetStunSuccessResponseType(request->type())) {
+    request->OnResponse(msg);
+  } else if (msg->type() == GetStunErrorResponseType(request->type())) {
+    request->OnErrorResponse(msg);
+  } else {
+    LOG(LERROR) << "Received response with wrong type: " << msg->type()
+                << " (expecting "
+                << GetStunSuccessResponseType(request->type()) << ")";
+    return false;
+  }
+
+  delete request;
+  return true;
+}
+
+bool StunRequestManager::CheckResponse(const char* data, size_t size) {
+  // Check the appropriate bytes of the stream to see if they match the
+  // transaction ID of a response we are expecting.
+
+  if (size < 20)
+    return false;
+
+  std::string id;
+  id.append(data + kStunTransactionIdOffset, kStunTransactionIdLength);
+
+  RequestMap::iterator iter = requests_.find(id);
+  if (iter == requests_.end())
+    return false;
+
+  // Parse the STUN message and continue processing as usual.
+
+  rtc::ByteBuffer buf(data, size);
+  rtc::scoped_ptr<StunMessage> response(iter->second->msg_->CreateNew());
+  if (!response->Read(&buf))
+    return false;
+
+  return CheckResponse(response.get());
+}
+
+StunRequest::StunRequest()
+    : count_(0), timeout_(false), manager_(0),
+      msg_(new StunMessage()), tstamp_(0) {
+  msg_->SetTransactionID(
+      rtc::CreateRandomString(kStunTransactionIdLength));
+}
+
+StunRequest::StunRequest(StunMessage* request)
+    : count_(0), timeout_(false), manager_(0),
+      msg_(request), tstamp_(0) {
+  msg_->SetTransactionID(
+      rtc::CreateRandomString(kStunTransactionIdLength));
+}
+
+StunRequest::~StunRequest() {
+  ASSERT(manager_ != NULL);
+  if (manager_) {
+    manager_->Remove(this);
+    manager_->thread_->Clear(this);
+  }
+  delete msg_;
+}
+
+void StunRequest::Construct() {
+  if (msg_->type() == 0) {
+    Prepare(msg_);
+    ASSERT(msg_->type() != 0);
+  }
+}
+
+int StunRequest::type() {
+  ASSERT(msg_ != NULL);
+  return msg_->type();
+}
+
+const StunMessage* StunRequest::msg() const {
+  return msg_;
+}
+
+uint32 StunRequest::Elapsed() const {
+  return rtc::TimeSince(tstamp_);
+}
+
+
+void StunRequest::set_manager(StunRequestManager* manager) {
+  ASSERT(!manager_);
+  manager_ = manager;
+}
+
+void StunRequest::OnMessage(rtc::Message* pmsg) {
+  ASSERT(manager_ != NULL);
+  ASSERT(pmsg->message_id == MSG_STUN_SEND);
+
+  if (timeout_) {
+    OnTimeout();
+    delete this;
+    return;
+  }
+
+  tstamp_ = rtc::Time();
+
+  rtc::ByteBuffer buf;
+  msg_->Write(&buf);
+  manager_->SignalSendPacket(buf.Data(), buf.Length(), this);
+
+  int delay = GetNextDelay();
+  manager_->thread_->PostDelayed(delay, this, MSG_STUN_SEND, NULL);
+}
+
+int StunRequest::GetNextDelay() {
+  int delay = DELAY_UNIT * rtc::_min(1 << count_, DELAY_MAX_FACTOR);
+  count_ += 1;
+  if (count_ == MAX_SENDS)
+    timeout_ = true;
+  return delay;
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/stunrequest.h b/webrtc/p2p/base/stunrequest.h
new file mode 100644
index 0000000..5fefc2f
--- /dev/null
+++ b/webrtc/p2p/base/stunrequest.h
@@ -0,0 +1,116 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_STUNREQUEST_H_
+#define WEBRTC_P2P_BASE_STUNREQUEST_H_
+
+#include <map>
+#include <string>
+#include "webrtc/p2p/base/stun.h"
+#include "webrtc/base/sigslot.h"
+#include "webrtc/base/thread.h"
+
+namespace cricket {
+
+class StunRequest;
+
+// Manages a set of STUN requests, sending and resending until we receive a
+// response or determine that the request has timed out.
+class StunRequestManager {
+public:
+  StunRequestManager(rtc::Thread* thread);
+  ~StunRequestManager();
+
+  // Starts sending the given request (perhaps after a delay).
+  void Send(StunRequest* request);
+  void SendDelayed(StunRequest* request, int delay);
+
+  // Removes a stun request that was added previously.  This will happen
+  // automatically when a request succeeds, fails, or times out.
+  void Remove(StunRequest* request);
+
+  // Removes all stun requests that were added previously.
+  void Clear();
+
+  // Determines whether the given message is a response to one of the
+  // outstanding requests, and if so, processes it appropriately.
+  bool CheckResponse(StunMessage* msg);
+  bool CheckResponse(const char* data, size_t size);
+
+  bool empty() { return requests_.empty(); }
+
+  // Raised when there are bytes to be sent.
+  sigslot::signal3<const void*, size_t, StunRequest*> SignalSendPacket;
+
+private:
+  typedef std::map<std::string, StunRequest*> RequestMap;
+
+  rtc::Thread* thread_;
+  RequestMap requests_;
+
+  friend class StunRequest;
+};
+
+// Represents an individual request to be sent.  The STUN message can either be
+// constructed beforehand or built on demand.
+class StunRequest : public rtc::MessageHandler {
+public:
+  StunRequest();
+  StunRequest(StunMessage* request);
+  virtual ~StunRequest();
+
+  // Causes our wrapped StunMessage to be Prepared
+  void Construct();
+
+  // The manager handling this request (if it has been scheduled for sending).
+  StunRequestManager* manager() { return manager_; }
+
+  // Returns the transaction ID of this request.
+  const std::string& id() { return msg_->transaction_id(); }
+
+  // Returns the STUN type of the request message.
+  int type();
+
+  // Returns a const pointer to |msg_|.
+  const StunMessage* msg() const;
+
+  // Time elapsed since last send (in ms)
+  uint32 Elapsed() const;
+
+protected:
+  int count_;
+  bool timeout_;
+
+  // Fills in a request object to be sent.  Note that request's transaction ID
+  // will already be set and cannot be changed.
+  virtual void Prepare(StunMessage* request) {}
+
+  // Called when the message receives a response or times out.
+  virtual void OnResponse(StunMessage* response) {}
+  virtual void OnErrorResponse(StunMessage* response) {}
+  virtual void OnTimeout() {}
+  virtual int GetNextDelay();
+
+private:
+  void set_manager(StunRequestManager* manager);
+
+  // Handles messages for sending and timeout.
+  void OnMessage(rtc::Message* pmsg);
+
+  StunRequestManager* manager_;
+  StunMessage* msg_;
+  uint32 tstamp_;
+
+  friend class StunRequestManager;
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_STUNREQUEST_H_
diff --git a/webrtc/p2p/base/stunrequest_unittest.cc b/webrtc/p2p/base/stunrequest_unittest.cc
new file mode 100644
index 0000000..3ff6cba
--- /dev/null
+++ b/webrtc/p2p/base/stunrequest_unittest.cc
@@ -0,0 +1,203 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/stunrequest.h"
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/helpers.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/ssladapter.h"
+#include "webrtc/base/timeutils.h"
+
+using namespace cricket;
+
+class StunRequestTest : public testing::Test,
+                        public sigslot::has_slots<> {
+ public:
+  StunRequestTest()
+      : manager_(rtc::Thread::Current()),
+        request_count_(0), response_(NULL),
+        success_(false), failure_(false), timeout_(false) {
+    manager_.SignalSendPacket.connect(this, &StunRequestTest::OnSendPacket);
+  }
+
+  void OnSendPacket(const void* data, size_t size, StunRequest* req) {
+    request_count_++;
+  }
+
+  void OnResponse(StunMessage* res) {
+    response_ = res;
+    success_ = true;
+  }
+  void OnErrorResponse(StunMessage* res) {
+    response_ = res;
+    failure_ = true;
+  }
+  void OnTimeout() {
+    timeout_ = true;
+  }
+
+ protected:
+  static StunMessage* CreateStunMessage(StunMessageType type,
+                                        StunMessage* req) {
+    StunMessage* msg = new StunMessage();
+    msg->SetType(type);
+    if (req) {
+      msg->SetTransactionID(req->transaction_id());
+    }
+    return msg;
+  }
+  static int TotalDelay(int sends) {
+    int total = 0;
+    for (int i = 0; i < sends; i++) {
+      if (i < 4)
+        total += 100 << i;
+      else
+        total += 1600;
+    }
+    return total;
+  }
+
+  StunRequestManager manager_;
+  int request_count_;
+  StunMessage* response_;
+  bool success_;
+  bool failure_;
+  bool timeout_;
+};
+
+// Forwards results to the test class.
+class StunRequestThunker : public StunRequest {
+ public:
+  StunRequestThunker(StunMessage* msg, StunRequestTest* test)
+      : StunRequest(msg), test_(test) {}
+  explicit StunRequestThunker(StunRequestTest* test) : test_(test) {}
+ private:
+  virtual void OnResponse(StunMessage* res) {
+    test_->OnResponse(res);
+  }
+  virtual void OnErrorResponse(StunMessage* res) {
+    test_->OnErrorResponse(res);
+  }
+  virtual void OnTimeout() {
+    test_->OnTimeout();
+  }
+
+  virtual void Prepare(StunMessage* request) {
+    request->SetType(STUN_BINDING_REQUEST);
+  }
+
+  StunRequestTest* test_;
+};
+
+// Test handling of a normal binding response.
+TEST_F(StunRequestTest, TestSuccess) {
+  StunMessage* req = CreateStunMessage(STUN_BINDING_REQUEST, NULL);
+
+  manager_.Send(new StunRequestThunker(req, this));
+  StunMessage* res = CreateStunMessage(STUN_BINDING_RESPONSE, req);
+  EXPECT_TRUE(manager_.CheckResponse(res));
+
+  EXPECT_TRUE(response_ == res);
+  EXPECT_TRUE(success_);
+  EXPECT_FALSE(failure_);
+  EXPECT_FALSE(timeout_);
+  delete res;
+}
+
+// Test handling of an error binding response.
+TEST_F(StunRequestTest, TestError) {
+  StunMessage* req = CreateStunMessage(STUN_BINDING_REQUEST, NULL);
+
+  manager_.Send(new StunRequestThunker(req, this));
+  StunMessage* res = CreateStunMessage(STUN_BINDING_ERROR_RESPONSE, req);
+  EXPECT_TRUE(manager_.CheckResponse(res));
+
+  EXPECT_TRUE(response_ == res);
+  EXPECT_FALSE(success_);
+  EXPECT_TRUE(failure_);
+  EXPECT_FALSE(timeout_);
+  delete res;
+}
+
+// Test handling of a binding response with the wrong transaction id.
+TEST_F(StunRequestTest, TestUnexpected) {
+  StunMessage* req = CreateStunMessage(STUN_BINDING_REQUEST, NULL);
+
+  manager_.Send(new StunRequestThunker(req, this));
+  StunMessage* res = CreateStunMessage(STUN_BINDING_RESPONSE, NULL);
+  EXPECT_FALSE(manager_.CheckResponse(res));
+
+  EXPECT_TRUE(response_ == NULL);
+  EXPECT_FALSE(success_);
+  EXPECT_FALSE(failure_);
+  EXPECT_FALSE(timeout_);
+  delete res;
+}
+
+// Test that requests are sent at the right times, and that the 9th request
+// (sent at 7900 ms) can be properly replied to.
+TEST_F(StunRequestTest, TestBackoff) {
+  StunMessage* req = CreateStunMessage(STUN_BINDING_REQUEST, NULL);
+
+  uint32 start = rtc::Time();
+  manager_.Send(new StunRequestThunker(req, this));
+  StunMessage* res = CreateStunMessage(STUN_BINDING_RESPONSE, req);
+  for (int i = 0; i < 9; ++i) {
+    while (request_count_ == i)
+      rtc::Thread::Current()->ProcessMessages(1);
+    int32 elapsed = rtc::TimeSince(start);
+    LOG(LS_INFO) << "STUN request #" << (i + 1)
+                 << " sent at " << elapsed << " ms";
+    EXPECT_GE(TotalDelay(i + 1), elapsed);
+  }
+  EXPECT_TRUE(manager_.CheckResponse(res));
+
+  EXPECT_TRUE(response_ == res);
+  EXPECT_TRUE(success_);
+  EXPECT_FALSE(failure_);
+  EXPECT_FALSE(timeout_);
+  delete res;
+}
+
+// Test that we timeout properly if no response is received in 9500 ms.
+TEST_F(StunRequestTest, TestTimeout) {
+  StunMessage* req = CreateStunMessage(STUN_BINDING_REQUEST, NULL);
+  StunMessage* res = CreateStunMessage(STUN_BINDING_RESPONSE, req);
+
+  manager_.Send(new StunRequestThunker(req, this));
+  rtc::Thread::Current()->ProcessMessages(10000);  // > STUN timeout
+  EXPECT_FALSE(manager_.CheckResponse(res));
+
+  EXPECT_TRUE(response_ == NULL);
+  EXPECT_FALSE(success_);
+  EXPECT_FALSE(failure_);
+  EXPECT_TRUE(timeout_);
+  delete res;
+}
+
+// Regression test for specific crash where we receive a response with the
+// same id as a request that doesn't have an underlying StunMessage yet.
+TEST_F(StunRequestTest, TestNoEmptyRequest) {
+  StunRequestThunker* request = new StunRequestThunker(this);
+
+  manager_.SendDelayed(request, 100);
+
+  StunMessage dummy_req;
+  dummy_req.SetTransactionID(request->id());
+  StunMessage* res = CreateStunMessage(STUN_BINDING_RESPONSE, &dummy_req);
+
+  EXPECT_TRUE(manager_.CheckResponse(res));
+
+  EXPECT_TRUE(response_ == res);
+  EXPECT_TRUE(success_);
+  EXPECT_FALSE(failure_);
+  EXPECT_FALSE(timeout_);
+  delete res;
+}
diff --git a/webrtc/p2p/base/stunserver.cc b/webrtc/p2p/base/stunserver.cc
new file mode 100644
index 0000000..fbc316b
--- /dev/null
+++ b/webrtc/p2p/base/stunserver.cc
@@ -0,0 +1,99 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/stunserver.h"
+
+#include "webrtc/base/bytebuffer.h"
+#include "webrtc/base/logging.h"
+
+namespace cricket {
+
+StunServer::StunServer(rtc::AsyncUDPSocket* socket) : socket_(socket) {
+  socket_->SignalReadPacket.connect(this, &StunServer::OnPacket);
+}
+
+StunServer::~StunServer() {
+  socket_->SignalReadPacket.disconnect(this);
+}
+
+void StunServer::OnPacket(
+    rtc::AsyncPacketSocket* socket, const char* buf, size_t size,
+    const rtc::SocketAddress& remote_addr,
+    const rtc::PacketTime& packet_time) {
+  // Parse the STUN message; eat any messages that fail to parse.
+  rtc::ByteBuffer bbuf(buf, size);
+  StunMessage msg;
+  if (!msg.Read(&bbuf)) {
+    return;
+  }
+
+  // TODO: If unknown non-optional (<= 0x7fff) attributes are found, send a
+  //       420 "Unknown Attribute" response.
+
+  // Send the message to the appropriate handler function.
+  switch (msg.type()) {
+    case STUN_BINDING_REQUEST:
+      OnBindingRequest(&msg, remote_addr);
+      break;
+
+    default:
+      SendErrorResponse(msg, remote_addr, 600, "Operation Not Supported");
+  }
+}
+
+void StunServer::OnBindingRequest(
+    StunMessage* msg, const rtc::SocketAddress& remote_addr) {
+  StunMessage response;
+  GetStunBindReqponse(msg, remote_addr, &response);
+  SendResponse(response, remote_addr);
+}
+
+void StunServer::SendErrorResponse(
+    const StunMessage& msg, const rtc::SocketAddress& addr,
+    int error_code, const char* error_desc) {
+  StunMessage err_msg;
+  err_msg.SetType(GetStunErrorResponseType(msg.type()));
+  err_msg.SetTransactionID(msg.transaction_id());
+
+  StunErrorCodeAttribute* err_code = StunAttribute::CreateErrorCode();
+  err_code->SetCode(error_code);
+  err_code->SetReason(error_desc);
+  err_msg.AddAttribute(err_code);
+
+  SendResponse(err_msg, addr);
+}
+
+void StunServer::SendResponse(
+    const StunMessage& msg, const rtc::SocketAddress& addr) {
+  rtc::ByteBuffer buf;
+  msg.Write(&buf);
+  rtc::PacketOptions options;
+  if (socket_->SendTo(buf.Data(), buf.Length(), addr, options) < 0)
+    LOG_ERR(LS_ERROR) << "sendto";
+}
+
+void StunServer::GetStunBindReqponse(StunMessage* request,
+                                     const rtc::SocketAddress& remote_addr,
+                                     StunMessage* response) const {
+  response->SetType(STUN_BINDING_RESPONSE);
+  response->SetTransactionID(request->transaction_id());
+
+  // Tell the user the address that we received their request from.
+  StunAddressAttribute* mapped_addr;
+  if (!request->IsLegacy()) {
+    mapped_addr = StunAttribute::CreateAddress(STUN_ATTR_MAPPED_ADDRESS);
+  } else {
+    mapped_addr = StunAttribute::CreateXorAddress(STUN_ATTR_XOR_MAPPED_ADDRESS);
+  }
+  mapped_addr->SetAddress(remote_addr);
+  response->AddAttribute(mapped_addr);
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/stunserver.h b/webrtc/p2p/base/stunserver.h
new file mode 100644
index 0000000..a7eeab1
--- /dev/null
+++ b/webrtc/p2p/base/stunserver.h
@@ -0,0 +1,66 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_STUNSERVER_H_
+#define WEBRTC_P2P_BASE_STUNSERVER_H_
+
+#include "webrtc/p2p/base/stun.h"
+#include "webrtc/base/asyncudpsocket.h"
+#include "webrtc/base/scoped_ptr.h"
+
+namespace cricket {
+
+const int STUN_SERVER_PORT = 3478;
+
+class StunServer : public sigslot::has_slots<> {
+ public:
+  // Creates a STUN server, which will listen on the given socket.
+  explicit StunServer(rtc::AsyncUDPSocket* socket);
+  // Removes the STUN server from the socket and deletes the socket.
+  ~StunServer();
+
+ protected:
+  // Slot for AsyncSocket.PacketRead:
+  void OnPacket(
+      rtc::AsyncPacketSocket* socket, const char* buf, size_t size,
+      const rtc::SocketAddress& remote_addr,
+      const rtc::PacketTime& packet_time);
+
+  // Handlers for the different types of STUN/TURN requests:
+  virtual void OnBindingRequest(StunMessage* msg,
+      const rtc::SocketAddress& addr);
+  void OnAllocateRequest(StunMessage* msg,
+      const rtc::SocketAddress& addr);
+  void OnSharedSecretRequest(StunMessage* msg,
+      const rtc::SocketAddress& addr);
+  void OnSendRequest(StunMessage* msg,
+      const rtc::SocketAddress& addr);
+
+  // Sends an error response to the given message back to the user.
+  void SendErrorResponse(
+      const StunMessage& msg, const rtc::SocketAddress& addr,
+      int error_code, const char* error_desc);
+
+  // Sends the given message to the appropriate destination.
+  void SendResponse(const StunMessage& msg,
+       const rtc::SocketAddress& addr);
+
+  // A helper method to compose a STUN binding response.
+  void GetStunBindReqponse(StunMessage* request,
+                           const rtc::SocketAddress& remote_addr,
+                           StunMessage* response) const;
+
+ private:
+  rtc::scoped_ptr<rtc::AsyncUDPSocket> socket_;
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_STUNSERVER_H_
diff --git a/webrtc/p2p/base/stunserver_unittest.cc b/webrtc/p2p/base/stunserver_unittest.cc
new file mode 100644
index 0000000..7266eae
--- /dev/null
+++ b/webrtc/p2p/base/stunserver_unittest.cc
@@ -0,0 +1,109 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <string>
+
+#include "webrtc/p2p/base/stunserver.h"
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/physicalsocketserver.h"
+#include "webrtc/base/testclient.h"
+#include "webrtc/base/thread.h"
+#include "webrtc/base/virtualsocketserver.h"
+
+using namespace cricket;
+
+static const rtc::SocketAddress server_addr("99.99.99.1", 3478);
+static const rtc::SocketAddress client_addr("1.2.3.4", 1234);
+
+class StunServerTest : public testing::Test {
+ public:
+  StunServerTest()
+    : pss_(new rtc::PhysicalSocketServer),
+      ss_(new rtc::VirtualSocketServer(pss_.get())),
+      worker_(ss_.get()) {
+  }
+  virtual void SetUp() {
+    server_.reset(new StunServer(
+        rtc::AsyncUDPSocket::Create(ss_.get(), server_addr)));
+    client_.reset(new rtc::TestClient(
+        rtc::AsyncUDPSocket::Create(ss_.get(), client_addr)));
+
+    worker_.Start();
+  }
+  void Send(const StunMessage& msg) {
+    rtc::ByteBuffer buf;
+    msg.Write(&buf);
+    Send(buf.Data(), static_cast<int>(buf.Length()));
+  }
+  void Send(const char* buf, int len) {
+    client_->SendTo(buf, len, server_addr);
+  }
+  StunMessage* Receive() {
+    StunMessage* msg = NULL;
+    rtc::TestClient::Packet* packet = client_->NextPacket();
+    if (packet) {
+      rtc::ByteBuffer buf(packet->buf, packet->size);
+      msg = new StunMessage();
+      msg->Read(&buf);
+      delete packet;
+    }
+    return msg;
+  }
+ private:
+  rtc::scoped_ptr<rtc::PhysicalSocketServer> pss_;
+  rtc::scoped_ptr<rtc::VirtualSocketServer> ss_;
+  rtc::Thread worker_;
+  rtc::scoped_ptr<StunServer> server_;
+  rtc::scoped_ptr<rtc::TestClient> client_;
+};
+
+// Disable for TSan v2, see
+// https://code.google.com/p/webrtc/issues/detail?id=2517 for details.
+#if !defined(THREAD_SANITIZER)
+
+TEST_F(StunServerTest, TestGood) {
+  StunMessage req;
+  std::string transaction_id = "0123456789ab";
+  req.SetType(STUN_BINDING_REQUEST);
+  req.SetTransactionID(transaction_id);
+  Send(req);
+
+  StunMessage* msg = Receive();
+  ASSERT_TRUE(msg != NULL);
+  EXPECT_EQ(STUN_BINDING_RESPONSE, msg->type());
+  EXPECT_EQ(req.transaction_id(), msg->transaction_id());
+
+  const StunAddressAttribute* mapped_addr =
+      msg->GetAddress(STUN_ATTR_MAPPED_ADDRESS);
+  EXPECT_TRUE(mapped_addr != NULL);
+  EXPECT_EQ(1, mapped_addr->family());
+  EXPECT_EQ(client_addr.port(), mapped_addr->port());
+  if (mapped_addr->ipaddr() != client_addr.ipaddr()) {
+    LOG(LS_WARNING) << "Warning: mapped IP ("
+                    << mapped_addr->ipaddr()
+                    << ") != local IP (" << client_addr.ipaddr()
+                    << ")";
+  }
+
+  delete msg;
+}
+
+#endif // if !defined(THREAD_SANITIZER)
+
+TEST_F(StunServerTest, TestBad) {
+  const char* bad = "this is a completely nonsensical message whose only "
+                    "purpose is to make the parser go 'ack'.  it doesn't "
+                    "look anything like a normal stun message";
+  Send(bad, static_cast<int>(strlen(bad)));
+
+  StunMessage* msg = Receive();
+  ASSERT_TRUE(msg == NULL);
+}
diff --git a/webrtc/p2p/base/tcpport.cc b/webrtc/p2p/base/tcpport.cc
new file mode 100644
index 0000000..be3068b
--- /dev/null
+++ b/webrtc/p2p/base/tcpport.cc
@@ -0,0 +1,321 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/tcpport.h"
+
+#include "webrtc/p2p/base/common.h"
+#include "webrtc/base/common.h"
+#include "webrtc/base/logging.h"
+
+namespace cricket {
+
+TCPPort::TCPPort(rtc::Thread* thread,
+                 rtc::PacketSocketFactory* factory,
+                 rtc::Network* network, const rtc::IPAddress& ip,
+                 int min_port, int max_port, const std::string& username,
+                 const std::string& password, bool allow_listen)
+    : Port(thread, LOCAL_PORT_TYPE, factory, network, ip, min_port, max_port,
+           username, password),
+      incoming_only_(false),
+      allow_listen_(allow_listen),
+      socket_(NULL),
+      error_(0) {
+  // TODO(mallinath) - Set preference value as per RFC 6544.
+  // http://b/issue?id=7141794
+}
+
+bool TCPPort::Init() {
+  if (allow_listen_) {
+    // Treat failure to create or bind a TCP socket as fatal.  This
+    // should never happen.
+    socket_ = socket_factory()->CreateServerTcpSocket(
+        rtc::SocketAddress(ip(), 0), min_port(), max_port(),
+        false /* ssl */);
+    if (!socket_) {
+      LOG_J(LS_ERROR, this) << "TCP socket creation failed.";
+      return false;
+    }
+    socket_->SignalNewConnection.connect(this, &TCPPort::OnNewConnection);
+    socket_->SignalAddressReady.connect(this, &TCPPort::OnAddressReady);
+  }
+  return true;
+}
+
+TCPPort::~TCPPort() {
+  delete socket_;
+  std::list<Incoming>::iterator it;
+  for (it = incoming_.begin(); it != incoming_.end(); ++it)
+    delete it->socket;
+  incoming_.clear();
+}
+
+Connection* TCPPort::CreateConnection(const Candidate& address,
+                                      CandidateOrigin origin) {
+  // We only support TCP protocols
+  if ((address.protocol() != TCP_PROTOCOL_NAME) &&
+      (address.protocol() != SSLTCP_PROTOCOL_NAME)) {
+    return NULL;
+  }
+
+  if (address.tcptype() == TCPTYPE_ACTIVE_STR ||
+      (address.tcptype().empty() && address.address().port() == 0)) {
+    // It's active only candidate, we should not try to create connections
+    // for these candidates.
+    return NULL;
+  }
+
+  // We can't accept TCP connections incoming on other ports
+  if (origin == ORIGIN_OTHER_PORT)
+    return NULL;
+
+  // Check if we are allowed to make outgoing TCP connections
+  if (incoming_only_ && (origin == ORIGIN_MESSAGE))
+    return NULL;
+
+  // We don't know how to act as an ssl server yet
+  if ((address.protocol() == SSLTCP_PROTOCOL_NAME) &&
+      (origin == ORIGIN_THIS_PORT)) {
+    return NULL;
+  }
+
+  if (!IsCompatibleAddress(address.address())) {
+    return NULL;
+  }
+
+  TCPConnection* conn = NULL;
+  if (rtc::AsyncPacketSocket* socket =
+      GetIncoming(address.address(), true)) {
+    socket->SignalReadPacket.disconnect(this);
+    conn = new TCPConnection(this, address, socket);
+  } else {
+    conn = new TCPConnection(this, address);
+  }
+  AddConnection(conn);
+  return conn;
+}
+
+void TCPPort::PrepareAddress() {
+  if (socket_) {
+    // If socket isn't bound yet the address will be added in
+    // OnAddressReady(). Socket may be in the CLOSED state if Listen()
+    // failed, we still want to add the socket address.
+    LOG(LS_VERBOSE) << "Preparing TCP address, current state: "
+                    << socket_->GetState();
+    if (socket_->GetState() == rtc::AsyncPacketSocket::STATE_BOUND ||
+        socket_->GetState() == rtc::AsyncPacketSocket::STATE_CLOSED)
+      AddAddress(socket_->GetLocalAddress(), socket_->GetLocalAddress(),
+                 rtc::SocketAddress(),
+                 TCP_PROTOCOL_NAME, TCPTYPE_PASSIVE_STR, LOCAL_PORT_TYPE,
+                 ICE_TYPE_PREFERENCE_HOST_TCP, 0, true);
+  } else {
+    LOG_J(LS_INFO, this) << "Not listening due to firewall restrictions.";
+    // Note: We still add the address, since otherwise the remote side won't
+    // recognize our incoming TCP connections.
+    AddAddress(rtc::SocketAddress(ip(), 0),
+               rtc::SocketAddress(ip(), 0), rtc::SocketAddress(),
+               TCP_PROTOCOL_NAME, TCPTYPE_ACTIVE_STR, LOCAL_PORT_TYPE,
+               ICE_TYPE_PREFERENCE_HOST_TCP, 0, true);
+  }
+}
+
+int TCPPort::SendTo(const void* data, size_t size,
+                    const rtc::SocketAddress& addr,
+                    const rtc::PacketOptions& options,
+                    bool payload) {
+  rtc::AsyncPacketSocket * socket = NULL;
+  if (TCPConnection * conn = static_cast<TCPConnection*>(GetConnection(addr))) {
+    socket = conn->socket();
+  } else {
+    socket = GetIncoming(addr);
+  }
+  if (!socket) {
+    LOG_J(LS_ERROR, this) << "Attempted to send to an unknown destination, "
+                          << addr.ToSensitiveString();
+    return -1;  // TODO: Set error_
+  }
+
+  int sent = socket->Send(data, size, options);
+  if (sent < 0) {
+    error_ = socket->GetError();
+    LOG_J(LS_ERROR, this) << "TCP send of " << size
+                          << " bytes failed with error " << error_;
+  }
+  return sent;
+}
+
+int TCPPort::GetOption(rtc::Socket::Option opt, int* value) {
+  if (socket_) {
+    return socket_->GetOption(opt, value);
+  } else {
+    return SOCKET_ERROR;
+  }
+}
+
+int TCPPort::SetOption(rtc::Socket::Option opt, int value) {
+  if (socket_) {
+    return socket_->SetOption(opt, value);
+  } else {
+    return SOCKET_ERROR;
+  }
+}
+
+int TCPPort::GetError() {
+  return error_;
+}
+
+void TCPPort::OnNewConnection(rtc::AsyncPacketSocket* socket,
+                              rtc::AsyncPacketSocket* new_socket) {
+  ASSERT(socket == socket_);
+
+  Incoming incoming;
+  incoming.addr = new_socket->GetRemoteAddress();
+  incoming.socket = new_socket;
+  incoming.socket->SignalReadPacket.connect(this, &TCPPort::OnReadPacket);
+  incoming.socket->SignalReadyToSend.connect(this, &TCPPort::OnReadyToSend);
+
+  LOG_J(LS_VERBOSE, this) << "Accepted connection from "
+                          << incoming.addr.ToSensitiveString();
+  incoming_.push_back(incoming);
+}
+
+rtc::AsyncPacketSocket* TCPPort::GetIncoming(
+    const rtc::SocketAddress& addr, bool remove) {
+  rtc::AsyncPacketSocket* socket = NULL;
+  for (std::list<Incoming>::iterator it = incoming_.begin();
+       it != incoming_.end(); ++it) {
+    if (it->addr == addr) {
+      socket = it->socket;
+      if (remove)
+        incoming_.erase(it);
+      break;
+    }
+  }
+  return socket;
+}
+
+void TCPPort::OnReadPacket(rtc::AsyncPacketSocket* socket,
+                           const char* data, size_t size,
+                           const rtc::SocketAddress& remote_addr,
+                           const rtc::PacketTime& packet_time) {
+  Port::OnReadPacket(data, size, remote_addr, PROTO_TCP);
+}
+
+void TCPPort::OnReadyToSend(rtc::AsyncPacketSocket* socket) {
+  Port::OnReadyToSend();
+}
+
+void TCPPort::OnAddressReady(rtc::AsyncPacketSocket* socket,
+                             const rtc::SocketAddress& address) {
+  AddAddress(address, address, rtc::SocketAddress(),
+             TCP_PROTOCOL_NAME, TCPTYPE_PASSIVE_STR, LOCAL_PORT_TYPE,
+             ICE_TYPE_PREFERENCE_HOST_TCP, 0, true);
+}
+
+TCPConnection::TCPConnection(TCPPort* port, const Candidate& candidate,
+                             rtc::AsyncPacketSocket* socket)
+    : Connection(port, 0, candidate), socket_(socket), error_(0) {
+  bool outgoing = (socket_ == NULL);
+  if (outgoing) {
+    // TODO: Handle failures here (unlikely since TCP).
+    int opts = (candidate.protocol() == SSLTCP_PROTOCOL_NAME) ?
+        rtc::PacketSocketFactory::OPT_SSLTCP : 0;
+    socket_ = port->socket_factory()->CreateClientTcpSocket(
+        rtc::SocketAddress(port->ip(), 0),
+        candidate.address(), port->proxy(), port->user_agent(), opts);
+    if (socket_) {
+      LOG_J(LS_VERBOSE, this) << "Connecting from "
+                              << socket_->GetLocalAddress().ToSensitiveString()
+                              << " to "
+                              << candidate.address().ToSensitiveString();
+      set_connected(false);
+      socket_->SignalConnect.connect(this, &TCPConnection::OnConnect);
+    } else {
+      LOG_J(LS_WARNING, this) << "Failed to create connection to "
+                              << candidate.address().ToSensitiveString();
+    }
+  } else {
+    // Incoming connections should match the network address.
+    ASSERT(socket_->GetLocalAddress().ipaddr() == port->ip());
+  }
+
+  if (socket_) {
+    socket_->SignalReadPacket.connect(this, &TCPConnection::OnReadPacket);
+    socket_->SignalReadyToSend.connect(this, &TCPConnection::OnReadyToSend);
+    socket_->SignalClose.connect(this, &TCPConnection::OnClose);
+  }
+}
+
+TCPConnection::~TCPConnection() {
+  delete socket_;
+}
+
+int TCPConnection::Send(const void* data, size_t size,
+                        const rtc::PacketOptions& options) {
+  if (!socket_) {
+    error_ = ENOTCONN;
+    return SOCKET_ERROR;
+  }
+
+  if (write_state() != STATE_WRITABLE) {
+    // TODO: Should STATE_WRITE_TIMEOUT return a non-blocking error?
+    error_ = EWOULDBLOCK;
+    return SOCKET_ERROR;
+  }
+  int sent = socket_->Send(data, size, options);
+  if (sent < 0) {
+    error_ = socket_->GetError();
+  } else {
+    send_rate_tracker_.Update(sent);
+  }
+  return sent;
+}
+
+int TCPConnection::GetError() {
+  return error_;
+}
+
+void TCPConnection::OnConnect(rtc::AsyncPacketSocket* socket) {
+  ASSERT(socket == socket_);
+  // Do not use this connection if the socket bound to a different address than
+  // the one we asked for. This is seen in Chrome, where TCP sockets cannot be
+  // given a binding address, and the platform is expected to pick the
+  // correct local address.
+  if (socket->GetLocalAddress().ipaddr() == port()->ip()) {
+    LOG_J(LS_VERBOSE, this) << "Connection established to "
+                            << socket->GetRemoteAddress().ToSensitiveString();
+    set_connected(true);
+  } else {
+    LOG_J(LS_WARNING, this) << "Dropping connection as TCP socket bound to a "
+                            << "different address from the local candidate.";
+    socket_->Close();
+  }
+}
+
+void TCPConnection::OnClose(rtc::AsyncPacketSocket* socket, int error) {
+  ASSERT(socket == socket_);
+  LOG_J(LS_VERBOSE, this) << "Connection closed with error " << error;
+  set_connected(false);
+  set_write_state(STATE_WRITE_TIMEOUT);
+}
+
+void TCPConnection::OnReadPacket(
+  rtc::AsyncPacketSocket* socket, const char* data, size_t size,
+  const rtc::SocketAddress& remote_addr,
+  const rtc::PacketTime& packet_time) {
+  ASSERT(socket == socket_);
+  Connection::OnReadPacket(data, size, packet_time);
+}
+
+void TCPConnection::OnReadyToSend(rtc::AsyncPacketSocket* socket) {
+  ASSERT(socket == socket_);
+  Connection::OnReadyToSend();
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/tcpport.h b/webrtc/p2p/base/tcpport.h
new file mode 100644
index 0000000..43e4936
--- /dev/null
+++ b/webrtc/p2p/base/tcpport.h
@@ -0,0 +1,136 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_TCPPORT_H_
+#define WEBRTC_P2P_BASE_TCPPORT_H_
+
+#include <list>
+#include <string>
+#include "webrtc/p2p/base/port.h"
+#include "webrtc/base/asyncpacketsocket.h"
+
+namespace cricket {
+
+class TCPConnection;
+
+// Communicates using a local TCP port.
+//
+// This class is designed to allow subclasses to take advantage of the
+// connection management provided by this class.  A subclass should take of all
+// packet sending and preparation, but when a packet is received, it should
+// call this TCPPort::OnReadPacket (3 arg) to dispatch to a connection.
+class TCPPort : public Port {
+ public:
+  static TCPPort* Create(rtc::Thread* thread,
+                         rtc::PacketSocketFactory* factory,
+                         rtc::Network* network,
+                         const rtc::IPAddress& ip,
+                         int min_port, int max_port,
+                         const std::string& username,
+                         const std::string& password,
+                         bool allow_listen) {
+    TCPPort* port = new TCPPort(thread, factory, network,
+                                ip, min_port, max_port,
+                                username, password, allow_listen);
+    if (!port->Init()) {
+      delete port;
+      port = NULL;
+    }
+    return port;
+  }
+  virtual ~TCPPort();
+
+  virtual Connection* CreateConnection(const Candidate& address,
+                                       CandidateOrigin origin);
+
+  virtual void PrepareAddress();
+
+  virtual int GetOption(rtc::Socket::Option opt, int* value);
+  virtual int SetOption(rtc::Socket::Option opt, int value);
+  virtual int GetError();
+
+ protected:
+  TCPPort(rtc::Thread* thread, rtc::PacketSocketFactory* factory,
+          rtc::Network* network, const rtc::IPAddress& ip,
+          int min_port, int max_port, const std::string& username,
+          const std::string& password, bool allow_listen);
+  bool Init();
+
+  // Handles sending using the local TCP socket.
+  virtual int SendTo(const void* data, size_t size,
+                     const rtc::SocketAddress& addr,
+                     const rtc::PacketOptions& options,
+                     bool payload);
+
+  // Accepts incoming TCP connection.
+  void OnNewConnection(rtc::AsyncPacketSocket* socket,
+                       rtc::AsyncPacketSocket* new_socket);
+
+ private:
+  struct Incoming {
+    rtc::SocketAddress addr;
+    rtc::AsyncPacketSocket* socket;
+  };
+
+  rtc::AsyncPacketSocket* GetIncoming(
+      const rtc::SocketAddress& addr, bool remove = false);
+
+  // Receives packet signal from the local TCP Socket.
+  void OnReadPacket(rtc::AsyncPacketSocket* socket,
+                    const char* data, size_t size,
+                    const rtc::SocketAddress& remote_addr,
+                    const rtc::PacketTime& packet_time);
+
+  void OnReadyToSend(rtc::AsyncPacketSocket* socket);
+
+  void OnAddressReady(rtc::AsyncPacketSocket* socket,
+                      const rtc::SocketAddress& address);
+
+  // TODO: Is this still needed?
+  bool incoming_only_;
+  bool allow_listen_;
+  rtc::AsyncPacketSocket* socket_;
+  int error_;
+  std::list<Incoming> incoming_;
+
+  friend class TCPConnection;
+};
+
+class TCPConnection : public Connection {
+ public:
+  // Connection is outgoing unless socket is specified
+  TCPConnection(TCPPort* port, const Candidate& candidate,
+                rtc::AsyncPacketSocket* socket = 0);
+  virtual ~TCPConnection();
+
+  virtual int Send(const void* data, size_t size,
+                   const rtc::PacketOptions& options);
+  virtual int GetError();
+
+  rtc::AsyncPacketSocket* socket() { return socket_; }
+
+ private:
+  void OnConnect(rtc::AsyncPacketSocket* socket);
+  void OnClose(rtc::AsyncPacketSocket* socket, int error);
+  void OnReadPacket(rtc::AsyncPacketSocket* socket,
+                    const char* data, size_t size,
+                    const rtc::SocketAddress& remote_addr,
+                    const rtc::PacketTime& packet_time);
+  void OnReadyToSend(rtc::AsyncPacketSocket* socket);
+
+  rtc::AsyncPacketSocket* socket_;
+  int error_;
+
+  friend class TCPPort;
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_TCPPORT_H_
diff --git a/webrtc/p2p/base/testrelayserver.h b/webrtc/p2p/base/testrelayserver.h
new file mode 100644
index 0000000..87cb9e5
--- /dev/null
+++ b/webrtc/p2p/base/testrelayserver.h
@@ -0,0 +1,101 @@
+/*
+ *  Copyright 2008 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_TESTRELAYSERVER_H_
+#define WEBRTC_P2P_BASE_TESTRELAYSERVER_H_
+
+#include "webrtc/p2p/base/relayserver.h"
+#include "webrtc/base/asynctcpsocket.h"
+#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/sigslot.h"
+#include "webrtc/base/socketadapters.h"
+#include "webrtc/base/thread.h"
+
+namespace cricket {
+
+// A test relay server. Useful for unit tests.
+class TestRelayServer : public sigslot::has_slots<> {
+ public:
+  TestRelayServer(rtc::Thread* thread,
+                  const rtc::SocketAddress& udp_int_addr,
+                  const rtc::SocketAddress& udp_ext_addr,
+                  const rtc::SocketAddress& tcp_int_addr,
+                  const rtc::SocketAddress& tcp_ext_addr,
+                  const rtc::SocketAddress& ssl_int_addr,
+                  const rtc::SocketAddress& ssl_ext_addr)
+      : server_(thread) {
+    server_.AddInternalSocket(rtc::AsyncUDPSocket::Create(
+        thread->socketserver(), udp_int_addr));
+    server_.AddExternalSocket(rtc::AsyncUDPSocket::Create(
+        thread->socketserver(), udp_ext_addr));
+
+    tcp_int_socket_.reset(CreateListenSocket(thread, tcp_int_addr));
+    tcp_ext_socket_.reset(CreateListenSocket(thread, tcp_ext_addr));
+    ssl_int_socket_.reset(CreateListenSocket(thread, ssl_int_addr));
+    ssl_ext_socket_.reset(CreateListenSocket(thread, ssl_ext_addr));
+  }
+  int GetConnectionCount() const {
+    return server_.GetConnectionCount();
+  }
+  rtc::SocketAddressPair GetConnection(int connection) const {
+    return server_.GetConnection(connection);
+  }
+  bool HasConnection(const rtc::SocketAddress& address) const {
+    return server_.HasConnection(address);
+  }
+
+ private:
+  rtc::AsyncSocket* CreateListenSocket(rtc::Thread* thread,
+      const rtc::SocketAddress& addr) {
+    rtc::AsyncSocket* socket =
+        thread->socketserver()->CreateAsyncSocket(addr.family(), SOCK_STREAM);
+    socket->Bind(addr);
+    socket->Listen(5);
+    socket->SignalReadEvent.connect(this, &TestRelayServer::OnAccept);
+    return socket;
+  }
+  void OnAccept(rtc::AsyncSocket* socket) {
+    bool external = (socket == tcp_ext_socket_.get() ||
+                     socket == ssl_ext_socket_.get());
+    bool ssl = (socket == ssl_int_socket_.get() ||
+                socket == ssl_ext_socket_.get());
+    rtc::AsyncSocket* raw_socket = socket->Accept(NULL);
+    if (raw_socket) {
+      rtc::AsyncTCPSocket* packet_socket = new rtc::AsyncTCPSocket(
+          (!ssl) ? raw_socket :
+          new rtc::AsyncSSLServerSocket(raw_socket), false);
+      if (!external) {
+        packet_socket->SignalClose.connect(this,
+            &TestRelayServer::OnInternalClose);
+        server_.AddInternalSocket(packet_socket);
+      } else {
+        packet_socket->SignalClose.connect(this,
+            &TestRelayServer::OnExternalClose);
+        server_.AddExternalSocket(packet_socket);
+      }
+    }
+  }
+  void OnInternalClose(rtc::AsyncPacketSocket* socket, int error) {
+    server_.RemoveInternalSocket(socket);
+  }
+  void OnExternalClose(rtc::AsyncPacketSocket* socket, int error) {
+    server_.RemoveExternalSocket(socket);
+  }
+ private:
+  cricket::RelayServer server_;
+  rtc::scoped_ptr<rtc::AsyncSocket> tcp_int_socket_;
+  rtc::scoped_ptr<rtc::AsyncSocket> tcp_ext_socket_;
+  rtc::scoped_ptr<rtc::AsyncSocket> ssl_int_socket_;
+  rtc::scoped_ptr<rtc::AsyncSocket> ssl_ext_socket_;
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_TESTRELAYSERVER_H_
diff --git a/webrtc/p2p/base/teststunserver.h b/webrtc/p2p/base/teststunserver.h
new file mode 100644
index 0000000..a2a8b6f
--- /dev/null
+++ b/webrtc/p2p/base/teststunserver.h
@@ -0,0 +1,58 @@
+/*
+ *  Copyright 2008 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_TESTSTUNSERVER_H_
+#define WEBRTC_P2P_BASE_TESTSTUNSERVER_H_
+
+#include "webrtc/p2p/base/stunserver.h"
+#include "webrtc/base/socketaddress.h"
+#include "webrtc/base/thread.h"
+
+namespace cricket {
+
+// A test STUN server. Useful for unit tests.
+class TestStunServer : StunServer {
+ public:
+  static TestStunServer* Create(rtc::Thread* thread,
+                                const rtc::SocketAddress& addr) {
+    rtc::AsyncSocket* socket =
+        thread->socketserver()->CreateAsyncSocket(addr.family(), SOCK_DGRAM);
+    rtc::AsyncUDPSocket* udp_socket =
+        rtc::AsyncUDPSocket::Create(socket, addr);
+
+    return new TestStunServer(udp_socket);
+  }
+
+  // Set a fake STUN address to return to the client.
+  void set_fake_stun_addr(const rtc::SocketAddress& addr) {
+    fake_stun_addr_ = addr;
+  }
+
+ private:
+  explicit TestStunServer(rtc::AsyncUDPSocket* socket) : StunServer(socket) {}
+
+  void OnBindingRequest(StunMessage* msg,
+                        const rtc::SocketAddress& remote_addr) OVERRIDE {
+    if (fake_stun_addr_.IsNil()) {
+      StunServer::OnBindingRequest(msg, remote_addr);
+    } else {
+      StunMessage response;
+      GetStunBindReqponse(msg, fake_stun_addr_, &response);
+      SendResponse(response, remote_addr);
+    }
+  }
+
+ private:
+  rtc::SocketAddress fake_stun_addr_;
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_TESTSTUNSERVER_H_
diff --git a/webrtc/p2p/base/testturnserver.h b/webrtc/p2p/base/testturnserver.h
new file mode 100644
index 0000000..19f73e7
--- /dev/null
+++ b/webrtc/p2p/base/testturnserver.h
@@ -0,0 +1,103 @@
+/*
+ *  Copyright 2012 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_TESTTURNSERVER_H_
+#define WEBRTC_P2P_BASE_TESTTURNSERVER_H_
+
+#include <string>
+#include <vector>
+
+#include "webrtc/p2p/base/basicpacketsocketfactory.h"
+#include "webrtc/p2p/base/stun.h"
+#include "webrtc/p2p/base/turnserver.h"
+#include "webrtc/base/asyncudpsocket.h"
+#include "webrtc/base/thread.h"
+
+namespace cricket {
+
+static const char kTestRealm[] = "example.org";
+static const char kTestSoftware[] = "TestTurnServer";
+
+class TestTurnRedirector : public TurnRedirectInterface {
+ public:
+  explicit TestTurnRedirector(const std::vector<rtc::SocketAddress>& addresses)
+      : alternate_server_addresses_(addresses),
+        iter_(alternate_server_addresses_.begin()) {
+  }
+
+  virtual bool ShouldRedirect(const rtc::SocketAddress&,
+                              rtc::SocketAddress* out) {
+    if (!out || iter_ == alternate_server_addresses_.end()) {
+      return false;
+    }
+    *out = *iter_++;
+    return true;
+  }
+
+ private:
+  const std::vector<rtc::SocketAddress>& alternate_server_addresses_;
+  std::vector<rtc::SocketAddress>::const_iterator iter_;
+};
+
+class TestTurnServer : public TurnAuthInterface {
+ public:
+  TestTurnServer(rtc::Thread* thread,
+                 const rtc::SocketAddress& udp_int_addr,
+                 const rtc::SocketAddress& udp_ext_addr)
+      : server_(thread) {
+    AddInternalSocket(udp_int_addr, cricket::PROTO_UDP);
+    server_.SetExternalSocketFactory(new rtc::BasicPacketSocketFactory(),
+        udp_ext_addr);
+    server_.set_realm(kTestRealm);
+    server_.set_software(kTestSoftware);
+    server_.set_auth_hook(this);
+  }
+
+  void set_enable_otu_nonce(bool enable) {
+    server_.set_enable_otu_nonce(enable);
+  }
+
+  TurnServer* server() { return &server_; }
+
+  void set_redirect_hook(TurnRedirectInterface* redirect_hook) {
+    server_.set_redirect_hook(redirect_hook);
+  }
+
+  void AddInternalSocket(const rtc::SocketAddress& int_addr,
+                         ProtocolType proto) {
+    rtc::Thread* thread = rtc::Thread::Current();
+    if (proto == cricket::PROTO_UDP) {
+      server_.AddInternalSocket(rtc::AsyncUDPSocket::Create(
+          thread->socketserver(), int_addr), proto);
+    } else if (proto == cricket::PROTO_TCP) {
+      // For TCP we need to create a server socket which can listen for incoming
+      // new connections.
+      rtc::AsyncSocket* socket =
+          thread->socketserver()->CreateAsyncSocket(SOCK_STREAM);
+      socket->Bind(int_addr);
+      socket->Listen(5);
+      server_.AddInternalServerSocket(socket, proto);
+    }
+  }
+
+ private:
+  // For this test server, succeed if the password is the same as the username.
+  // Obviously, do not use this in a production environment.
+  virtual bool GetKey(const std::string& username, const std::string& realm,
+                      std::string* key) {
+    return ComputeStunCredentialHash(username, realm, username, key);
+  }
+
+  TurnServer server_;
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_TESTTURNSERVER_H_
diff --git a/webrtc/p2p/base/transport.cc b/webrtc/p2p/base/transport.cc
new file mode 100644
index 0000000..05c455e
--- /dev/null
+++ b/webrtc/p2p/base/transport.cc
@@ -0,0 +1,960 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/transport.h"
+
+#include "webrtc/p2p/base/candidate.h"
+#include "webrtc/p2p/base/constants.h"
+#include "webrtc/p2p/base/parsing.h"
+#include "webrtc/p2p/base/port.h"
+#include "webrtc/p2p/base/sessionmanager.h"
+#include "webrtc/p2p/base/transportchannelimpl.h"
+#include "webrtc/libjingle/xmllite/xmlelement.h"
+#include "webrtc/libjingle/xmpp/constants.h"
+#include "webrtc/base/bind.h"
+#include "webrtc/base/common.h"
+#include "webrtc/base/logging.h"
+
+namespace cricket {
+
+using rtc::Bind;
+
+enum {
+  MSG_ONSIGNALINGREADY = 1,
+  MSG_ONREMOTECANDIDATE,
+  MSG_READSTATE,
+  MSG_WRITESTATE,
+  MSG_REQUESTSIGNALING,
+  MSG_CANDIDATEREADY,
+  MSG_ROUTECHANGE,
+  MSG_CONNECTING,
+  MSG_CANDIDATEALLOCATIONCOMPLETE,
+  MSG_ROLECONFLICT,
+  MSG_COMPLETED,
+  MSG_FAILED,
+};
+
+struct ChannelParams : public rtc::MessageData {
+  ChannelParams() : channel(NULL), candidate(NULL) {}
+  explicit ChannelParams(int component)
+      : component(component), channel(NULL), candidate(NULL) {}
+  explicit ChannelParams(Candidate* candidate)
+      : channel(NULL), candidate(candidate) {
+  }
+
+  ~ChannelParams() {
+    delete candidate;
+  }
+
+  std::string name;
+  int component;
+  TransportChannelImpl* channel;
+  Candidate* candidate;
+};
+
+static std::string IceProtoToString(TransportProtocol proto) {
+  std::string proto_str;
+  switch (proto) {
+    case ICEPROTO_GOOGLE:
+      proto_str = "gice";
+      break;
+    case ICEPROTO_HYBRID:
+      proto_str = "hybrid";
+      break;
+    case ICEPROTO_RFC5245:
+      proto_str = "ice";
+      break;
+    default:
+      ASSERT(false);
+      break;
+  }
+  return proto_str;
+}
+
+static bool VerifyIceParams(const TransportDescription& desc) {
+  // For legacy protocols.
+  if (desc.ice_ufrag.empty() && desc.ice_pwd.empty())
+    return true;
+
+  if (desc.ice_ufrag.length() < ICE_UFRAG_MIN_LENGTH ||
+      desc.ice_ufrag.length() > ICE_UFRAG_MAX_LENGTH) {
+    return false;
+  }
+  if (desc.ice_pwd.length() < ICE_PWD_MIN_LENGTH ||
+      desc.ice_pwd.length() > ICE_PWD_MAX_LENGTH) {
+    return false;
+  }
+  return true;
+}
+
+bool BadTransportDescription(const std::string& desc, std::string* err_desc) {
+  if (err_desc) {
+    *err_desc = desc;
+  }
+  LOG(LS_ERROR) << desc;
+  return false;
+}
+
+bool IceCredentialsChanged(const std::string& old_ufrag,
+                           const std::string& old_pwd,
+                           const std::string& new_ufrag,
+                           const std::string& new_pwd) {
+  // TODO(jiayl): The standard (RFC 5245 Section 9.1.1.1) says that ICE should
+  // restart when both the ufrag and password are changed, but we do restart
+  // when either ufrag or passwrod is changed to keep compatible with GICE. We
+  // should clean this up when GICE is no longer used.
+  return (old_ufrag != new_ufrag) || (old_pwd != new_pwd);
+}
+
+static bool IceCredentialsChanged(const TransportDescription& old_desc,
+                                  const TransportDescription& new_desc) {
+  return IceCredentialsChanged(old_desc.ice_ufrag, old_desc.ice_pwd,
+                               new_desc.ice_ufrag, new_desc.ice_pwd);
+}
+
+Transport::Transport(rtc::Thread* signaling_thread,
+                     rtc::Thread* worker_thread,
+                     const std::string& content_name,
+                     const std::string& type,
+                     PortAllocator* allocator)
+  : signaling_thread_(signaling_thread),
+    worker_thread_(worker_thread),
+    content_name_(content_name),
+    type_(type),
+    allocator_(allocator),
+    destroyed_(false),
+    readable_(TRANSPORT_STATE_NONE),
+    writable_(TRANSPORT_STATE_NONE),
+    was_writable_(false),
+    connect_requested_(false),
+    ice_role_(ICEROLE_UNKNOWN),
+    tiebreaker_(0),
+    protocol_(ICEPROTO_HYBRID),
+    remote_ice_mode_(ICEMODE_FULL) {
+}
+
+Transport::~Transport() {
+  ASSERT(signaling_thread_->IsCurrent());
+  ASSERT(destroyed_);
+}
+
+void Transport::SetIceRole(IceRole role) {
+  worker_thread_->Invoke<void>(Bind(&Transport::SetIceRole_w, this, role));
+}
+
+void Transport::SetIdentity(rtc::SSLIdentity* identity) {
+  worker_thread_->Invoke<void>(Bind(&Transport::SetIdentity_w, this, identity));
+}
+
+bool Transport::GetIdentity(rtc::SSLIdentity** identity) {
+  // The identity is set on the worker thread, so for safety it must also be
+  // acquired on the worker thread.
+  return worker_thread_->Invoke<bool>(
+      Bind(&Transport::GetIdentity_w, this, identity));
+}
+
+bool Transport::GetRemoteCertificate(rtc::SSLCertificate** cert) {
+  // Channels can be deleted on the worker thread, so for safety the remote
+  // certificate is acquired on the worker thread.
+  return worker_thread_->Invoke<bool>(
+      Bind(&Transport::GetRemoteCertificate_w, this, cert));
+}
+
+bool Transport::GetRemoteCertificate_w(rtc::SSLCertificate** cert) {
+  ASSERT(worker_thread()->IsCurrent());
+  if (channels_.empty())
+    return false;
+
+  ChannelMap::iterator iter = channels_.begin();
+  return iter->second->GetRemoteCertificate(cert);
+}
+
+bool Transport::SetLocalTransportDescription(
+    const TransportDescription& description,
+    ContentAction action,
+    std::string* error_desc) {
+  return worker_thread_->Invoke<bool>(Bind(
+      &Transport::SetLocalTransportDescription_w, this,
+      description, action, error_desc));
+}
+
+bool Transport::SetRemoteTransportDescription(
+    const TransportDescription& description,
+    ContentAction action,
+    std::string* error_desc) {
+  return worker_thread_->Invoke<bool>(Bind(
+      &Transport::SetRemoteTransportDescription_w, this,
+      description, action, error_desc));
+}
+
+TransportChannelImpl* Transport::CreateChannel(int component) {
+  return worker_thread_->Invoke<TransportChannelImpl*>(Bind(
+      &Transport::CreateChannel_w, this, component));
+}
+
+TransportChannelImpl* Transport::CreateChannel_w(int component) {
+  ASSERT(worker_thread()->IsCurrent());
+  TransportChannelImpl *impl;
+  rtc::CritScope cs(&crit_);
+
+  // Create the entry if it does not exist.
+  bool impl_exists = false;
+  if (channels_.find(component) == channels_.end()) {
+    impl = CreateTransportChannel(component);
+    channels_[component] = ChannelMapEntry(impl);
+  } else {
+    impl = channels_[component].get();
+    impl_exists = true;
+  }
+
+  // Increase the ref count.
+  channels_[component].AddRef();
+  destroyed_ = false;
+
+  if (impl_exists) {
+    // If this is an existing channel, we should just return it without
+    // connecting to all the signal again.
+    return impl;
+  }
+
+  // Push down our transport state to the new channel.
+  impl->SetIceRole(ice_role_);
+  impl->SetIceTiebreaker(tiebreaker_);
+  // TODO(ronghuawu): Change CreateChannel_w to be able to return error since
+  // below Apply**Description_w calls can fail.
+  if (local_description_)
+    ApplyLocalTransportDescription_w(impl, NULL);
+  if (remote_description_)
+    ApplyRemoteTransportDescription_w(impl, NULL);
+  if (local_description_ && remote_description_)
+    ApplyNegotiatedTransportDescription_w(impl, NULL);
+
+  impl->SignalReadableState.connect(this, &Transport::OnChannelReadableState);
+  impl->SignalWritableState.connect(this, &Transport::OnChannelWritableState);
+  impl->SignalRequestSignaling.connect(
+      this, &Transport::OnChannelRequestSignaling);
+  impl->SignalCandidateReady.connect(this, &Transport::OnChannelCandidateReady);
+  impl->SignalRouteChange.connect(this, &Transport::OnChannelRouteChange);
+  impl->SignalCandidatesAllocationDone.connect(
+      this, &Transport::OnChannelCandidatesAllocationDone);
+  impl->SignalRoleConflict.connect(this, &Transport::OnRoleConflict);
+  impl->SignalConnectionRemoved.connect(
+      this, &Transport::OnChannelConnectionRemoved);
+
+  if (connect_requested_) {
+    impl->Connect();
+    if (channels_.size() == 1) {
+      // If this is the first channel, then indicate that we have started
+      // connecting.
+      signaling_thread()->Post(this, MSG_CONNECTING, NULL);
+    }
+  }
+  return impl;
+}
+
+TransportChannelImpl* Transport::GetChannel(int component) {
+  rtc::CritScope cs(&crit_);
+  ChannelMap::iterator iter = channels_.find(component);
+  return (iter != channels_.end()) ? iter->second.get() : NULL;
+}
+
+bool Transport::HasChannels() {
+  rtc::CritScope cs(&crit_);
+  return !channels_.empty();
+}
+
+void Transport::DestroyChannel(int component) {
+  worker_thread_->Invoke<void>(Bind(
+      &Transport::DestroyChannel_w, this, component));
+}
+
+void Transport::DestroyChannel_w(int component) {
+  ASSERT(worker_thread()->IsCurrent());
+
+  TransportChannelImpl* impl = NULL;
+  {
+    rtc::CritScope cs(&crit_);
+    ChannelMap::iterator iter = channels_.find(component);
+    if (iter == channels_.end())
+      return;
+
+    iter->second.DecRef();
+    if (!iter->second.ref()) {
+      impl = iter->second.get();
+      channels_.erase(iter);
+    }
+  }
+
+  if (connect_requested_ && channels_.empty()) {
+    // We're no longer attempting to connect.
+    signaling_thread()->Post(this, MSG_CONNECTING, NULL);
+  }
+
+  if (impl) {
+    // Check in case the deleted channel was the only non-writable channel.
+    OnChannelWritableState(impl);
+    DestroyTransportChannel(impl);
+  }
+}
+
+void Transport::ConnectChannels() {
+  ASSERT(signaling_thread()->IsCurrent());
+  worker_thread_->Invoke<void>(Bind(&Transport::ConnectChannels_w, this));
+}
+
+void Transport::ConnectChannels_w() {
+  ASSERT(worker_thread()->IsCurrent());
+  if (connect_requested_ || channels_.empty())
+    return;
+  connect_requested_ = true;
+  signaling_thread()->Post(
+      this, MSG_CANDIDATEREADY, NULL);
+
+  if (!local_description_) {
+    // TOOD(mallinath) : TransportDescription(TD) shouldn't be generated here.
+    // As Transport must know TD is offer or answer and cricket::Transport
+    // doesn't have the capability to decide it. This should be set by the
+    // Session.
+    // Session must generate local TD before remote candidates pushed when
+    // initiate request initiated by the remote.
+    LOG(LS_INFO) << "Transport::ConnectChannels_w: No local description has "
+                 << "been set. Will generate one.";
+    TransportDescription desc(NS_GINGLE_P2P, std::vector<std::string>(),
+                              rtc::CreateRandomString(ICE_UFRAG_LENGTH),
+                              rtc::CreateRandomString(ICE_PWD_LENGTH),
+                              ICEMODE_FULL, CONNECTIONROLE_NONE, NULL,
+                              Candidates());
+    SetLocalTransportDescription_w(desc, CA_OFFER, NULL);
+  }
+
+  CallChannels_w(&TransportChannelImpl::Connect);
+  if (!channels_.empty()) {
+    signaling_thread()->Post(this, MSG_CONNECTING, NULL);
+  }
+}
+
+void Transport::OnConnecting_s() {
+  ASSERT(signaling_thread()->IsCurrent());
+  SignalConnecting(this);
+}
+
+void Transport::DestroyAllChannels() {
+  ASSERT(signaling_thread()->IsCurrent());
+  worker_thread_->Invoke<void>(
+      Bind(&Transport::DestroyAllChannels_w, this));
+  worker_thread()->Clear(this);
+  signaling_thread()->Clear(this);
+  destroyed_ = true;
+}
+
+void Transport::DestroyAllChannels_w() {
+  ASSERT(worker_thread()->IsCurrent());
+  std::vector<TransportChannelImpl*> impls;
+  {
+    rtc::CritScope cs(&crit_);
+    for (ChannelMap::iterator iter = channels_.begin();
+         iter != channels_.end();
+         ++iter) {
+      iter->second.DecRef();
+      if (!iter->second.ref())
+        impls.push_back(iter->second.get());
+      }
+    }
+  channels_.clear();
+
+
+  for (size_t i = 0; i < impls.size(); ++i)
+    DestroyTransportChannel(impls[i]);
+}
+
+void Transport::ResetChannels() {
+  ASSERT(signaling_thread()->IsCurrent());
+  worker_thread_->Invoke<void>(Bind(&Transport::ResetChannels_w, this));
+}
+
+void Transport::ResetChannels_w() {
+  ASSERT(worker_thread()->IsCurrent());
+
+  // We are no longer attempting to connect
+  connect_requested_ = false;
+
+  // Clear out the old messages, they aren't relevant
+  rtc::CritScope cs(&crit_);
+  ready_candidates_.clear();
+
+  // Reset all of the channels
+  CallChannels_w(&TransportChannelImpl::Reset);
+}
+
+void Transport::OnSignalingReady() {
+  ASSERT(signaling_thread()->IsCurrent());
+  if (destroyed_) return;
+
+  worker_thread()->Post(this, MSG_ONSIGNALINGREADY, NULL);
+
+  // Notify the subclass.
+  OnTransportSignalingReady();
+}
+
+void Transport::CallChannels_w(TransportChannelFunc func) {
+  ASSERT(worker_thread()->IsCurrent());
+  rtc::CritScope cs(&crit_);
+  for (ChannelMap::iterator iter = channels_.begin();
+       iter != channels_.end();
+       ++iter) {
+    ((iter->second.get())->*func)();
+  }
+}
+
+bool Transport::VerifyCandidate(const Candidate& cand, std::string* error) {
+  // No address zero.
+  if (cand.address().IsNil() || cand.address().IsAny()) {
+    *error = "candidate has address of zero";
+    return false;
+  }
+
+  // Disallow all ports below 1024, except for 80 and 443 on public addresses.
+  int port = cand.address().port();
+  if (cand.protocol() == TCP_PROTOCOL_NAME &&
+      (cand.tcptype() == TCPTYPE_ACTIVE_STR || port == 0)) {
+    // Expected for active-only candidates per
+    // http://tools.ietf.org/html/rfc6544#section-4.5 so no error.
+    // Libjingle clients emit port 0, in "active" mode.
+    return true;
+  }
+  if (port < 1024) {
+    if ((port != 80) && (port != 443)) {
+      *error = "candidate has port below 1024, but not 80 or 443";
+      return false;
+    }
+
+    if (cand.address().IsPrivateIP()) {
+      *error = "candidate has port of 80 or 443 with private IP address";
+      return false;
+    }
+  }
+
+  return true;
+}
+
+
+bool Transport::GetStats(TransportStats* stats) {
+  ASSERT(signaling_thread()->IsCurrent());
+  return worker_thread_->Invoke<bool>(Bind(
+      &Transport::GetStats_w, this, stats));
+}
+
+bool Transport::GetStats_w(TransportStats* stats) {
+  ASSERT(worker_thread()->IsCurrent());
+  stats->content_name = content_name();
+  stats->channel_stats.clear();
+  for (ChannelMap::iterator iter = channels_.begin();
+       iter != channels_.end();
+       ++iter) {
+    TransportChannelStats substats;
+    substats.component = iter->second->component();
+    if (!iter->second->GetStats(&substats.connection_infos)) {
+      return false;
+    }
+    stats->channel_stats.push_back(substats);
+  }
+  return true;
+}
+
+bool Transport::GetSslRole(rtc::SSLRole* ssl_role) const {
+  return worker_thread_->Invoke<bool>(Bind(
+      &Transport::GetSslRole_w, this, ssl_role));
+}
+
+void Transport::OnRemoteCandidates(const std::vector<Candidate>& candidates) {
+  for (std::vector<Candidate>::const_iterator iter = candidates.begin();
+       iter != candidates.end();
+       ++iter) {
+    OnRemoteCandidate(*iter);
+  }
+}
+
+void Transport::OnRemoteCandidate(const Candidate& candidate) {
+  ASSERT(signaling_thread()->IsCurrent());
+  if (destroyed_) return;
+
+  if (!HasChannel(candidate.component())) {
+    LOG(LS_WARNING) << "Ignoring candidate for unknown component "
+                    << candidate.component();
+    return;
+  }
+
+  ChannelParams* params = new ChannelParams(new Candidate(candidate));
+  worker_thread()->Post(this, MSG_ONREMOTECANDIDATE, params);
+}
+
+void Transport::OnRemoteCandidate_w(const Candidate& candidate) {
+  ASSERT(worker_thread()->IsCurrent());
+  ChannelMap::iterator iter = channels_.find(candidate.component());
+  // It's ok for a channel to go away while this message is in transit.
+  if (iter != channels_.end()) {
+    iter->second->OnCandidate(candidate);
+  }
+}
+
+void Transport::OnChannelReadableState(TransportChannel* channel) {
+  ASSERT(worker_thread()->IsCurrent());
+  signaling_thread()->Post(this, MSG_READSTATE, NULL);
+}
+
+void Transport::OnChannelReadableState_s() {
+  ASSERT(signaling_thread()->IsCurrent());
+  TransportState readable = GetTransportState_s(true);
+  if (readable_ != readable) {
+    readable_ = readable;
+    SignalReadableState(this);
+  }
+}
+
+void Transport::OnChannelWritableState(TransportChannel* channel) {
+  ASSERT(worker_thread()->IsCurrent());
+  signaling_thread()->Post(this, MSG_WRITESTATE, NULL);
+
+  MaybeCompleted_w();
+}
+
+void Transport::OnChannelWritableState_s() {
+  ASSERT(signaling_thread()->IsCurrent());
+  TransportState writable = GetTransportState_s(false);
+  if (writable_ != writable) {
+    was_writable_ = (writable_ == TRANSPORT_STATE_ALL);
+    writable_ = writable;
+    SignalWritableState(this);
+  }
+}
+
+TransportState Transport::GetTransportState_s(bool read) {
+  ASSERT(signaling_thread()->IsCurrent());
+  rtc::CritScope cs(&crit_);
+  bool any = false;
+  bool all = !channels_.empty();
+  for (ChannelMap::iterator iter = channels_.begin();
+       iter != channels_.end();
+       ++iter) {
+    bool b = (read ? iter->second->readable() :
+      iter->second->writable());
+    any = any || b;
+    all = all && b;
+  }
+  if (all) {
+    return TRANSPORT_STATE_ALL;
+  } else if (any) {
+    return TRANSPORT_STATE_SOME;
+  } else {
+    return TRANSPORT_STATE_NONE;
+  }
+}
+
+void Transport::OnChannelRequestSignaling(TransportChannelImpl* channel) {
+  ASSERT(worker_thread()->IsCurrent());
+  ChannelParams* params = new ChannelParams(channel->component());
+  signaling_thread()->Post(this, MSG_REQUESTSIGNALING, params);
+}
+
+void Transport::OnChannelRequestSignaling_s(int component) {
+  ASSERT(signaling_thread()->IsCurrent());
+  LOG(LS_INFO) << "Transport: " << content_name_ << ", allocating candidates";
+  // Resetting ICE state for the channel.
+  {
+    rtc::CritScope cs(&crit_);
+    ChannelMap::iterator iter = channels_.find(component);
+    if (iter != channels_.end())
+      iter->second.set_candidates_allocated(false);
+  }
+  SignalRequestSignaling(this);
+}
+
+void Transport::OnChannelCandidateReady(TransportChannelImpl* channel,
+                                        const Candidate& candidate) {
+  ASSERT(worker_thread()->IsCurrent());
+  rtc::CritScope cs(&crit_);
+  ready_candidates_.push_back(candidate);
+
+  // We hold any messages until the client lets us connect.
+  if (connect_requested_) {
+    signaling_thread()->Post(
+        this, MSG_CANDIDATEREADY, NULL);
+  }
+}
+
+void Transport::OnChannelCandidateReady_s() {
+  ASSERT(signaling_thread()->IsCurrent());
+  ASSERT(connect_requested_);
+
+  std::vector<Candidate> candidates;
+  {
+    rtc::CritScope cs(&crit_);
+    candidates.swap(ready_candidates_);
+  }
+
+  // we do the deleting of Candidate* here to keep the new above and
+  // delete below close to each other
+  if (!candidates.empty()) {
+    SignalCandidatesReady(this, candidates);
+  }
+}
+
+void Transport::OnChannelRouteChange(TransportChannel* channel,
+                                     const Candidate& remote_candidate) {
+  ASSERT(worker_thread()->IsCurrent());
+  ChannelParams* params = new ChannelParams(new Candidate(remote_candidate));
+  params->channel = static_cast<cricket::TransportChannelImpl*>(channel);
+  signaling_thread()->Post(this, MSG_ROUTECHANGE, params);
+}
+
+void Transport::OnChannelRouteChange_s(const TransportChannel* channel,
+                                       const Candidate& remote_candidate) {
+  ASSERT(signaling_thread()->IsCurrent());
+  SignalRouteChange(this, remote_candidate.component(), remote_candidate);
+}
+
+void Transport::OnChannelCandidatesAllocationDone(
+    TransportChannelImpl* channel) {
+  ASSERT(worker_thread()->IsCurrent());
+  rtc::CritScope cs(&crit_);
+  ChannelMap::iterator iter = channels_.find(channel->component());
+  ASSERT(iter != channels_.end());
+  LOG(LS_INFO) << "Transport: " << content_name_ << ", component "
+               << channel->component() << " allocation complete";
+  iter->second.set_candidates_allocated(true);
+
+  // If all channels belonging to this Transport got signal, then
+  // forward this signal to upper layer.
+  // Can this signal arrive before all transport channels are created?
+  for (iter = channels_.begin(); iter != channels_.end(); ++iter) {
+    if (!iter->second.candidates_allocated())
+      return;
+  }
+  signaling_thread_->Post(this, MSG_CANDIDATEALLOCATIONCOMPLETE);
+
+  MaybeCompleted_w();
+}
+
+void Transport::OnChannelCandidatesAllocationDone_s() {
+  ASSERT(signaling_thread()->IsCurrent());
+  LOG(LS_INFO) << "Transport: " << content_name_ << " allocation complete";
+  SignalCandidatesAllocationDone(this);
+}
+
+void Transport::OnRoleConflict(TransportChannelImpl* channel) {
+  signaling_thread_->Post(this, MSG_ROLECONFLICT);
+}
+
+void Transport::OnChannelConnectionRemoved(TransportChannelImpl* channel) {
+  ASSERT(worker_thread()->IsCurrent());
+  MaybeCompleted_w();
+
+  // Check if the state is now Failed.
+  // Failed is only available in the Controlling ICE role.
+  if (channel->GetIceRole() != ICEROLE_CONTROLLING) {
+    return;
+  }
+
+  ChannelMap::iterator iter = channels_.find(channel->component());
+  ASSERT(iter != channels_.end());
+  // Failed can only occur after candidate allocation has stopped.
+  if (!iter->second.candidates_allocated()) {
+    return;
+  }
+
+  size_t connections = channel->GetConnectionCount();
+  if (connections == 0) {
+    // A Transport has failed if any of its channels have no remaining
+    // connections.
+    signaling_thread_->Post(this, MSG_FAILED);
+  }
+}
+
+void Transport::MaybeCompleted_w() {
+  ASSERT(worker_thread()->IsCurrent());
+
+  // A Transport's ICE process is completed if all of its channels are writable,
+  // have finished allocating candidates, and have pruned all but one of their
+  // connections.
+  ChannelMap::const_iterator iter;
+  for (iter = channels_.begin(); iter != channels_.end(); ++iter) {
+    const TransportChannelImpl* channel = iter->second.get();
+    if (!(channel->writable() &&
+          channel->GetConnectionCount() == 1 &&
+          channel->GetIceRole() == ICEROLE_CONTROLLING &&
+          iter->second.candidates_allocated())) {
+      return;
+    }
+  }
+
+  signaling_thread_->Post(this, MSG_COMPLETED);
+}
+
+void Transport::SetIceRole_w(IceRole role) {
+  rtc::CritScope cs(&crit_);
+  ice_role_ = role;
+  for (ChannelMap::iterator iter = channels_.begin();
+       iter != channels_.end(); ++iter) {
+    iter->second->SetIceRole(ice_role_);
+  }
+}
+
+void Transport::SetRemoteIceMode_w(IceMode mode) {
+  rtc::CritScope cs(&crit_);
+  remote_ice_mode_ = mode;
+  // Shouldn't channels be created after this method executed?
+  for (ChannelMap::iterator iter = channels_.begin();
+       iter != channels_.end(); ++iter) {
+    iter->second->SetRemoteIceMode(remote_ice_mode_);
+  }
+}
+
+bool Transport::SetLocalTransportDescription_w(
+    const TransportDescription& desc,
+    ContentAction action,
+    std::string* error_desc) {
+  bool ret = true;
+  rtc::CritScope cs(&crit_);
+
+  if (!VerifyIceParams(desc)) {
+    return BadTransportDescription("Invalid ice-ufrag or ice-pwd length",
+                                   error_desc);
+  }
+
+  if (local_description_ && IceCredentialsChanged(*local_description_, desc)) {
+    IceRole new_ice_role = (action == CA_OFFER) ? ICEROLE_CONTROLLING
+                                                : ICEROLE_CONTROLLED;
+
+    // It must be called before ApplyLocalTransportDescription_w, which may
+    // trigger an ICE restart and depends on the new ICE role.
+    SetIceRole_w(new_ice_role);
+  }
+
+  local_description_.reset(new TransportDescription(desc));
+
+  for (ChannelMap::iterator iter = channels_.begin();
+       iter != channels_.end(); ++iter) {
+    ret &= ApplyLocalTransportDescription_w(iter->second.get(), error_desc);
+  }
+  if (!ret)
+    return false;
+
+  // If PRANSWER/ANSWER is set, we should decide transport protocol type.
+  if (action == CA_PRANSWER || action == CA_ANSWER) {
+    ret &= NegotiateTransportDescription_w(action, error_desc);
+  }
+  return ret;
+}
+
+bool Transport::SetRemoteTransportDescription_w(
+    const TransportDescription& desc,
+    ContentAction action,
+    std::string* error_desc) {
+  bool ret = true;
+  rtc::CritScope cs(&crit_);
+
+  if (!VerifyIceParams(desc)) {
+    return BadTransportDescription("Invalid ice-ufrag or ice-pwd length",
+                                   error_desc);
+  }
+
+  remote_description_.reset(new TransportDescription(desc));
+  for (ChannelMap::iterator iter = channels_.begin();
+       iter != channels_.end(); ++iter) {
+    ret &= ApplyRemoteTransportDescription_w(iter->second.get(), error_desc);
+  }
+
+  // If PRANSWER/ANSWER is set, we should decide transport protocol type.
+  if (action == CA_PRANSWER || action == CA_ANSWER) {
+    ret = NegotiateTransportDescription_w(CA_OFFER, error_desc);
+  }
+  return ret;
+}
+
+bool Transport::ApplyLocalTransportDescription_w(TransportChannelImpl* ch,
+                                                 std::string* error_desc) {
+  // If existing protocol_type is HYBRID, we may have not chosen the final
+  // protocol type, so update the channel protocol type from the
+  // local description. Otherwise, skip updating the protocol type.
+  // We check for HYBRID to avoid accidental changes; in the case of a
+  // session renegotiation, the new offer will have the google-ice ICE option,
+  // so we need to make sure we don't switch back from ICE mode to HYBRID
+  // when this happens.
+  // There are some other ways we could have solved this, but this is the
+  // simplest. The ultimate solution will be to get rid of GICE altogether.
+  IceProtocolType protocol_type;
+  if (ch->GetIceProtocolType(&protocol_type) &&
+      protocol_type == ICEPROTO_HYBRID) {
+    ch->SetIceProtocolType(
+        TransportProtocolFromDescription(local_description()));
+  }
+  ch->SetIceCredentials(local_description_->ice_ufrag,
+                        local_description_->ice_pwd);
+  return true;
+}
+
+bool Transport::ApplyRemoteTransportDescription_w(TransportChannelImpl* ch,
+                                                  std::string* error_desc) {
+  ch->SetRemoteIceCredentials(remote_description_->ice_ufrag,
+                              remote_description_->ice_pwd);
+  return true;
+}
+
+bool Transport::ApplyNegotiatedTransportDescription_w(
+    TransportChannelImpl* channel, std::string* error_desc) {
+  channel->SetIceProtocolType(protocol_);
+  channel->SetRemoteIceMode(remote_ice_mode_);
+  return true;
+}
+
+bool Transport::NegotiateTransportDescription_w(ContentAction local_role,
+                                                std::string* error_desc) {
+  // TODO(ekr@rtfm.com): This is ICE-specific stuff. Refactor into
+  // P2PTransport.
+  const TransportDescription* offer;
+  const TransportDescription* answer;
+
+  if (local_role == CA_OFFER) {
+    offer = local_description_.get();
+    answer = remote_description_.get();
+  } else {
+    offer = remote_description_.get();
+    answer = local_description_.get();
+  }
+
+  TransportProtocol offer_proto = TransportProtocolFromDescription(offer);
+  TransportProtocol answer_proto = TransportProtocolFromDescription(answer);
+
+  // If offered protocol is gice/ice, then we expect to receive matching
+  // protocol in answer, anything else is treated as an error.
+  // HYBRID is not an option when offered specific protocol.
+  // If offered protocol is HYBRID and answered protocol is HYBRID then
+  // gice is preferred protocol.
+  // TODO(mallinath) - Answer from local or remote should't have both ice
+  // and gice support. It should always pick which protocol it wants to use.
+  // Once WebRTC stops supporting gice (for backward compatibility), HYBRID in
+  // answer must be treated as error.
+  if ((offer_proto == ICEPROTO_GOOGLE || offer_proto == ICEPROTO_RFC5245) &&
+      (offer_proto != answer_proto)) {
+    std::ostringstream desc;
+    desc << "Offer and answer protocol mismatch: "
+         << IceProtoToString(offer_proto)
+         << " vs "
+         << IceProtoToString(answer_proto);
+    return BadTransportDescription(desc.str(), error_desc);
+  }
+  protocol_ = answer_proto == ICEPROTO_HYBRID ? ICEPROTO_GOOGLE : answer_proto;
+
+  // If transport is in ICEROLE_CONTROLLED and remote end point supports only
+  // ice_lite, this local end point should take CONTROLLING role.
+  if (ice_role_ == ICEROLE_CONTROLLED &&
+      remote_description_->ice_mode == ICEMODE_LITE) {
+    SetIceRole_w(ICEROLE_CONTROLLING);
+  }
+
+  // Update remote ice_mode to all existing channels.
+  remote_ice_mode_ = remote_description_->ice_mode;
+
+  // Now that we have negotiated everything, push it downward.
+  // Note that we cache the result so that if we have race conditions
+  // between future SetRemote/SetLocal invocations and new channel
+  // creation, we have the negotiation state saved until a new
+  // negotiation happens.
+  for (ChannelMap::iterator iter = channels_.begin();
+       iter != channels_.end();
+       ++iter) {
+    if (!ApplyNegotiatedTransportDescription_w(iter->second.get(), error_desc))
+      return false;
+  }
+  return true;
+}
+
+void Transport::OnMessage(rtc::Message* msg) {
+  switch (msg->message_id) {
+    case MSG_ONSIGNALINGREADY:
+      CallChannels_w(&TransportChannelImpl::OnSignalingReady);
+      break;
+    case MSG_ONREMOTECANDIDATE: {
+        ChannelParams* params = static_cast<ChannelParams*>(msg->pdata);
+        OnRemoteCandidate_w(*params->candidate);
+        delete params;
+      }
+      break;
+    case MSG_CONNECTING:
+      OnConnecting_s();
+      break;
+    case MSG_READSTATE:
+      OnChannelReadableState_s();
+      break;
+    case MSG_WRITESTATE:
+      OnChannelWritableState_s();
+      break;
+    case MSG_REQUESTSIGNALING: {
+        ChannelParams* params = static_cast<ChannelParams*>(msg->pdata);
+        OnChannelRequestSignaling_s(params->component);
+        delete params;
+      }
+      break;
+    case MSG_CANDIDATEREADY:
+      OnChannelCandidateReady_s();
+      break;
+    case MSG_ROUTECHANGE: {
+        ChannelParams* params = static_cast<ChannelParams*>(msg->pdata);
+        OnChannelRouteChange_s(params->channel, *params->candidate);
+        delete params;
+      }
+      break;
+    case MSG_CANDIDATEALLOCATIONCOMPLETE:
+      OnChannelCandidatesAllocationDone_s();
+      break;
+    case MSG_ROLECONFLICT:
+      SignalRoleConflict();
+      break;
+    case MSG_COMPLETED:
+      SignalCompleted(this);
+      break;
+    case MSG_FAILED:
+      SignalFailed(this);
+      break;
+  }
+}
+
+bool TransportParser::ParseAddress(const buzz::XmlElement* elem,
+                                   const buzz::QName& address_name,
+                                   const buzz::QName& port_name,
+                                   rtc::SocketAddress* address,
+                                   ParseError* error) {
+  if (!elem->HasAttr(address_name))
+    return BadParse("address does not have " + address_name.LocalPart(), error);
+  if (!elem->HasAttr(port_name))
+    return BadParse("address does not have " + port_name.LocalPart(), error);
+
+  address->SetIP(elem->Attr(address_name));
+  std::istringstream ist(elem->Attr(port_name));
+  int port = 0;
+  ist >> port;
+  address->SetPort(port);
+
+  return true;
+}
+
+// We're GICE if the namespace is NS_GOOGLE_P2P, or if NS_JINGLE_ICE_UDP is
+// used and the GICE ice-option is set.
+TransportProtocol TransportProtocolFromDescription(
+    const TransportDescription* desc) {
+  ASSERT(desc != NULL);
+  if (desc->transport_type == NS_JINGLE_ICE_UDP) {
+    return (desc->HasOption(ICE_OPTION_GICE)) ?
+        ICEPROTO_HYBRID : ICEPROTO_RFC5245;
+  }
+  return ICEPROTO_GOOGLE;
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/transport.h b/webrtc/p2p/base/transport.h
new file mode 100644
index 0000000..ab772fe
--- /dev/null
+++ b/webrtc/p2p/base/transport.h
@@ -0,0 +1,513 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+// A Transport manages a set of named channels of the same type.
+//
+// Subclasses choose the appropriate class to instantiate for each channel;
+// however, this base class keeps track of the channels by name, watches their
+// state changes (in order to update the manager's state), and forwards
+// requests to begin connecting or to reset to each of the channels.
+//
+// On Threading:  Transport performs work on both the signaling and worker
+// threads.  For subclasses, the rule is that all signaling related calls will
+// be made on the signaling thread and all channel related calls (including
+// signaling for a channel) will be made on the worker thread.  When
+// information needs to be sent between the two threads, this class should do
+// the work (e.g., OnRemoteCandidate).
+//
+// Note: Subclasses must call DestroyChannels() in their own constructors.
+// It is not possible to do so here because the subclass constructor will
+// already have run.
+
+#ifndef WEBRTC_P2P_BASE_TRANSPORT_H_
+#define WEBRTC_P2P_BASE_TRANSPORT_H_
+
+#include <map>
+#include <string>
+#include <vector>
+#include "webrtc/p2p/base/candidate.h"
+#include "webrtc/p2p/base/constants.h"
+#include "webrtc/p2p/base/sessiondescription.h"
+#include "webrtc/p2p/base/transportinfo.h"
+#include "webrtc/base/criticalsection.h"
+#include "webrtc/base/messagequeue.h"
+#include "webrtc/base/sigslot.h"
+#include "webrtc/base/sslstreamadapter.h"
+
+namespace rtc {
+class Thread;
+}
+
+namespace buzz {
+class QName;
+class XmlElement;
+}
+
+namespace cricket {
+
+struct ParseError;
+struct WriteError;
+class CandidateTranslator;
+class PortAllocator;
+class SessionManager;
+class Session;
+class TransportChannel;
+class TransportChannelImpl;
+
+typedef std::vector<buzz::XmlElement*> XmlElements;
+typedef std::vector<Candidate> Candidates;
+
+// Used to parse and serialize (write) transport candidates.  For
+// convenience of old code, Transports will implement TransportParser.
+// Parse/Write seems better than Serialize/Deserialize or
+// Create/Translate.
+class TransportParser {
+ public:
+  // The incoming Translator value may be null, in which case
+  // ParseCandidates should return false if there are candidates to
+  // parse (indicating a failure to parse).  If the Translator is null
+  // and there are no candidates to parse, then return true,
+  // indicating a successful parse of 0 candidates.
+
+  // Parse or write a transport description, including ICE credentials and
+  // any DTLS fingerprint. Since only Jingle has transport descriptions, these
+  // functions are only used when serializing to Jingle.
+  virtual bool ParseTransportDescription(const buzz::XmlElement* elem,
+                                         const CandidateTranslator* translator,
+                                         TransportDescription* tdesc,
+                                         ParseError* error) = 0;
+  virtual bool WriteTransportDescription(const TransportDescription& tdesc,
+                                         const CandidateTranslator* translator,
+                                         buzz::XmlElement** tdesc_elem,
+                                         WriteError* error) = 0;
+
+
+  // Parse a single candidate. This must be used when parsing Gingle
+  // candidates, since there is no enclosing transport description.
+  virtual bool ParseGingleCandidate(const buzz::XmlElement* elem,
+                                    const CandidateTranslator* translator,
+                                    Candidate* candidates,
+                                    ParseError* error) = 0;
+  virtual bool WriteGingleCandidate(const Candidate& candidate,
+                                    const CandidateTranslator* translator,
+                                    buzz::XmlElement** candidate_elem,
+                                    WriteError* error) = 0;
+
+  // Helper function to parse an element describing an address.  This
+  // retrieves the IP and port from the given element and verifies
+  // that they look like plausible values.
+  bool ParseAddress(const buzz::XmlElement* elem,
+                    const buzz::QName& address_name,
+                    const buzz::QName& port_name,
+                    rtc::SocketAddress* address,
+                    ParseError* error);
+
+  virtual ~TransportParser() {}
+};
+
+// For "writable" and "readable", we need to differentiate between
+// none, all, and some.
+enum TransportState {
+  TRANSPORT_STATE_NONE = 0,
+  TRANSPORT_STATE_SOME,
+  TRANSPORT_STATE_ALL
+};
+
+// Stats that we can return about the connections for a transport channel.
+// TODO(hta): Rename to ConnectionStats
+struct ConnectionInfo {
+  ConnectionInfo()
+      : best_connection(false),
+        writable(false),
+        readable(false),
+        timeout(false),
+        new_connection(false),
+        rtt(0),
+        sent_total_bytes(0),
+        sent_bytes_second(0),
+        recv_total_bytes(0),
+        recv_bytes_second(0),
+        key(NULL) {}
+
+  bool best_connection;        // Is this the best connection we have?
+  bool writable;               // Has this connection received a STUN response?
+  bool readable;               // Has this connection received a STUN request?
+  bool timeout;                // Has this connection timed out?
+  bool new_connection;         // Is this a newly created connection?
+  size_t rtt;                  // The STUN RTT for this connection.
+  size_t sent_total_bytes;     // Total bytes sent on this connection.
+  size_t sent_bytes_second;    // Bps over the last measurement interval.
+  size_t recv_total_bytes;     // Total bytes received on this connection.
+  size_t recv_bytes_second;    // Bps over the last measurement interval.
+  Candidate local_candidate;   // The local candidate for this connection.
+  Candidate remote_candidate;  // The remote candidate for this connection.
+  void* key;                   // A static value that identifies this conn.
+};
+
+// Information about all the connections of a channel.
+typedef std::vector<ConnectionInfo> ConnectionInfos;
+
+// Information about a specific channel
+struct TransportChannelStats {
+  int component;
+  ConnectionInfos connection_infos;
+};
+
+// Information about all the channels of a transport.
+// TODO(hta): Consider if a simple vector is as good as a map.
+typedef std::vector<TransportChannelStats> TransportChannelStatsList;
+
+// Information about the stats of a transport.
+struct TransportStats {
+  std::string content_name;
+  TransportChannelStatsList channel_stats;
+};
+
+bool BadTransportDescription(const std::string& desc, std::string* err_desc);
+
+bool IceCredentialsChanged(const std::string& old_ufrag,
+                           const std::string& old_pwd,
+                           const std::string& new_ufrag,
+                           const std::string& new_pwd);
+
+class Transport : public rtc::MessageHandler,
+                  public sigslot::has_slots<> {
+ public:
+  Transport(rtc::Thread* signaling_thread,
+            rtc::Thread* worker_thread,
+            const std::string& content_name,
+            const std::string& type,
+            PortAllocator* allocator);
+  virtual ~Transport();
+
+  // Returns the signaling thread. The app talks to Transport on this thread.
+  rtc::Thread* signaling_thread() { return signaling_thread_; }
+  // Returns the worker thread. The actual networking is done on this thread.
+  rtc::Thread* worker_thread() { return worker_thread_; }
+
+  // Returns the content_name of this transport.
+  const std::string& content_name() const { return content_name_; }
+  // Returns the type of this transport.
+  const std::string& type() const { return type_; }
+
+  // Returns the port allocator object for this transport.
+  PortAllocator* port_allocator() { return allocator_; }
+
+  // Returns the readable and states of this manager.  These bits are the ORs
+  // of the corresponding bits on the managed channels.  Each time one of these
+  // states changes, a signal is raised.
+  // TODO: Replace uses of readable() and writable() with
+  // any_channels_readable() and any_channels_writable().
+  bool readable() const { return any_channels_readable(); }
+  bool writable() const { return any_channels_writable(); }
+  bool was_writable() const { return was_writable_; }
+  bool any_channels_readable() const {
+    return (readable_ == TRANSPORT_STATE_SOME ||
+            readable_ == TRANSPORT_STATE_ALL);
+  }
+  bool any_channels_writable() const {
+    return (writable_ == TRANSPORT_STATE_SOME ||
+            writable_ == TRANSPORT_STATE_ALL);
+  }
+  bool all_channels_readable() const {
+    return (readable_ == TRANSPORT_STATE_ALL);
+  }
+  bool all_channels_writable() const {
+    return (writable_ == TRANSPORT_STATE_ALL);
+  }
+  sigslot::signal1<Transport*> SignalReadableState;
+  sigslot::signal1<Transport*> SignalWritableState;
+  sigslot::signal1<Transport*> SignalCompleted;
+  sigslot::signal1<Transport*> SignalFailed;
+
+  // Returns whether the client has requested the channels to connect.
+  bool connect_requested() const { return connect_requested_; }
+
+  void SetIceRole(IceRole role);
+  IceRole ice_role() const { return ice_role_; }
+
+  void SetIceTiebreaker(uint64 IceTiebreaker) { tiebreaker_ = IceTiebreaker; }
+  uint64 IceTiebreaker() { return tiebreaker_; }
+
+  // Must be called before applying local session description.
+  void SetIdentity(rtc::SSLIdentity* identity);
+
+  // Get a copy of the local identity provided by SetIdentity.
+  bool GetIdentity(rtc::SSLIdentity** identity);
+
+  // Get a copy of the remote certificate in use by the specified channel.
+  bool GetRemoteCertificate(rtc::SSLCertificate** cert);
+
+  TransportProtocol protocol() const { return protocol_; }
+
+  // Create, destroy, and lookup the channels of this type by their components.
+  TransportChannelImpl* CreateChannel(int component);
+  // Note: GetChannel may lead to race conditions, since the mutex is not held
+  // after the pointer is returned.
+  TransportChannelImpl* GetChannel(int component);
+  // Note: HasChannel does not lead to race conditions, unlike GetChannel.
+  bool HasChannel(int component) {
+    return (NULL != GetChannel(component));
+  }
+  bool HasChannels();
+  void DestroyChannel(int component);
+
+  // Set the local TransportDescription to be used by TransportChannels.
+  // This should be called before ConnectChannels().
+  bool SetLocalTransportDescription(const TransportDescription& description,
+                                    ContentAction action,
+                                    std::string* error_desc);
+
+  // Set the remote TransportDescription to be used by TransportChannels.
+  bool SetRemoteTransportDescription(const TransportDescription& description,
+                                     ContentAction action,
+                                     std::string* error_desc);
+
+  // Tells all current and future channels to start connecting.  When the first
+  // channel begins connecting, the following signal is raised.
+  void ConnectChannels();
+  sigslot::signal1<Transport*> SignalConnecting;
+
+  // Resets all of the channels back to their initial state.  They are no
+  // longer connecting.
+  void ResetChannels();
+
+  // Destroys every channel created so far.
+  void DestroyAllChannels();
+
+  bool GetStats(TransportStats* stats);
+
+  // Before any stanza is sent, the manager will request signaling.  Once
+  // signaling is available, the client should call OnSignalingReady.  Once
+  // this occurs, the transport (or its channels) can send any waiting stanzas.
+  // OnSignalingReady invokes OnTransportSignalingReady and then forwards this
+  // signal to each channel.
+  sigslot::signal1<Transport*> SignalRequestSignaling;
+  void OnSignalingReady();
+
+  // Handles sending of ready candidates and receiving of remote candidates.
+  sigslot::signal2<Transport*,
+                   const std::vector<Candidate>&> SignalCandidatesReady;
+
+  sigslot::signal1<Transport*> SignalCandidatesAllocationDone;
+  void OnRemoteCandidates(const std::vector<Candidate>& candidates);
+
+  // If candidate is not acceptable, returns false and sets error.
+  // Call this before calling OnRemoteCandidates.
+  virtual bool VerifyCandidate(const Candidate& candidate,
+                               std::string* error);
+
+  // Signals when the best connection for a channel changes.
+  sigslot::signal3<Transport*,
+                   int,  // component
+                   const Candidate&> SignalRouteChange;
+
+  // A transport message has generated an transport-specific error.  The
+  // stanza that caused the error is available in session_msg.  If false is
+  // returned, the error is considered unrecoverable, and the session is
+  // terminated.
+  // TODO(juberti): Remove these obsolete functions once Session no longer
+  // references them.
+  virtual void OnTransportError(const buzz::XmlElement* error) {}
+  sigslot::signal6<Transport*, const buzz::XmlElement*, const buzz::QName&,
+                   const std::string&, const std::string&,
+                   const buzz::XmlElement*>
+      SignalTransportError;
+
+  // Forwards the signal from TransportChannel to BaseSession.
+  sigslot::signal0<> SignalRoleConflict;
+
+  virtual bool GetSslRole(rtc::SSLRole* ssl_role) const;
+
+ protected:
+  // These are called by Create/DestroyChannel above in order to create or
+  // destroy the appropriate type of channel.
+  virtual TransportChannelImpl* CreateTransportChannel(int component) = 0;
+  virtual void DestroyTransportChannel(TransportChannelImpl* channel) = 0;
+
+  // Informs the subclass that we received the signaling ready message.
+  virtual void OnTransportSignalingReady() {}
+
+  // The current local transport description, for use by derived classes
+  // when performing transport description negotiation.
+  const TransportDescription* local_description() const {
+    return local_description_.get();
+  }
+
+  // The current remote transport description, for use by derived classes
+  // when performing transport description negotiation.
+  const TransportDescription* remote_description() const {
+    return remote_description_.get();
+  }
+
+  virtual void SetIdentity_w(rtc::SSLIdentity* identity) {}
+
+  virtual bool GetIdentity_w(rtc::SSLIdentity** identity) {
+    return false;
+  }
+
+  // Pushes down the transport parameters from the local description, such
+  // as the ICE ufrag and pwd.
+  // Derived classes can override, but must call the base as well.
+  virtual bool ApplyLocalTransportDescription_w(TransportChannelImpl* channel,
+                                                std::string* error_desc);
+
+  // Pushes down remote ice credentials from the remote description to the
+  // transport channel.
+  virtual bool ApplyRemoteTransportDescription_w(TransportChannelImpl* ch,
+                                                 std::string* error_desc);
+
+  // Negotiates the transport parameters based on the current local and remote
+  // transport description, such at the version of ICE to use, and whether DTLS
+  // should be activated.
+  // Derived classes can negotiate their specific parameters here, but must call
+  // the base as well.
+  virtual bool NegotiateTransportDescription_w(ContentAction local_role,
+                                               std::string* error_desc);
+
+  // Pushes down the transport parameters obtained via negotiation.
+  // Derived classes can set their specific parameters here, but must call the
+  // base as well.
+  virtual bool ApplyNegotiatedTransportDescription_w(
+      TransportChannelImpl* channel, std::string* error_desc);
+
+  virtual bool GetSslRole_w(rtc::SSLRole* ssl_role) const {
+    return false;
+  }
+
+ private:
+  struct ChannelMapEntry {
+    ChannelMapEntry() : impl_(NULL), candidates_allocated_(false), ref_(0) {}
+    explicit ChannelMapEntry(TransportChannelImpl *impl)
+        : impl_(impl),
+          candidates_allocated_(false),
+          ref_(0) {
+    }
+
+    void AddRef() { ++ref_; }
+    void DecRef() {
+      ASSERT(ref_ > 0);
+      --ref_;
+    }
+    int ref() const { return ref_; }
+
+    TransportChannelImpl* get() const { return impl_; }
+    TransportChannelImpl* operator->() const  { return impl_; }
+    void set_candidates_allocated(bool status) {
+      candidates_allocated_ = status;
+    }
+    bool candidates_allocated() const { return candidates_allocated_; }
+
+  private:
+    TransportChannelImpl *impl_;
+    bool candidates_allocated_;
+    int ref_;
+  };
+
+  // Candidate component => ChannelMapEntry
+  typedef std::map<int, ChannelMapEntry> ChannelMap;
+
+  // Called when the state of a channel changes.
+  void OnChannelReadableState(TransportChannel* channel);
+  void OnChannelWritableState(TransportChannel* channel);
+
+  // Called when a channel requests signaling.
+  void OnChannelRequestSignaling(TransportChannelImpl* channel);
+
+  // Called when a candidate is ready from remote peer.
+  void OnRemoteCandidate(const Candidate& candidate);
+  // Called when a candidate is ready from channel.
+  void OnChannelCandidateReady(TransportChannelImpl* channel,
+                               const Candidate& candidate);
+  void OnChannelRouteChange(TransportChannel* channel,
+                            const Candidate& remote_candidate);
+  void OnChannelCandidatesAllocationDone(TransportChannelImpl* channel);
+  // Called when there is ICE role change.
+  void OnRoleConflict(TransportChannelImpl* channel);
+  // Called when the channel removes a connection.
+  void OnChannelConnectionRemoved(TransportChannelImpl* channel);
+
+  // Dispatches messages to the appropriate handler (below).
+  void OnMessage(rtc::Message* msg);
+
+  // These are versions of the above methods that are called only on a
+  // particular thread (s = signaling, w = worker).  The above methods post or
+  // send a message to invoke this version.
+  TransportChannelImpl* CreateChannel_w(int component);
+  void DestroyChannel_w(int component);
+  void ConnectChannels_w();
+  void ResetChannels_w();
+  void DestroyAllChannels_w();
+  void OnRemoteCandidate_w(const Candidate& candidate);
+  void OnChannelReadableState_s();
+  void OnChannelWritableState_s();
+  void OnChannelRequestSignaling_s(int component);
+  void OnConnecting_s();
+  void OnChannelRouteChange_s(const TransportChannel* channel,
+                              const Candidate& remote_candidate);
+  void OnChannelCandidatesAllocationDone_s();
+
+  // Helper function that invokes the given function on every channel.
+  typedef void (TransportChannelImpl::* TransportChannelFunc)();
+  void CallChannels_w(TransportChannelFunc func);
+
+  // Computes the OR of the channel's read or write state (argument picks).
+  TransportState GetTransportState_s(bool read);
+
+  void OnChannelCandidateReady_s();
+
+  void SetIceRole_w(IceRole role);
+  void SetRemoteIceMode_w(IceMode mode);
+  bool SetLocalTransportDescription_w(const TransportDescription& desc,
+                                      ContentAction action,
+                                      std::string* error_desc);
+  bool SetRemoteTransportDescription_w(const TransportDescription& desc,
+                                       ContentAction action,
+                                       std::string* error_desc);
+  bool GetStats_w(TransportStats* infos);
+  bool GetRemoteCertificate_w(rtc::SSLCertificate** cert);
+
+  // Sends SignalCompleted if we are now in that state.
+  void MaybeCompleted_w();
+
+  rtc::Thread* signaling_thread_;
+  rtc::Thread* worker_thread_;
+  std::string content_name_;
+  std::string type_;
+  PortAllocator* allocator_;
+  bool destroyed_;
+  TransportState readable_;
+  TransportState writable_;
+  bool was_writable_;
+  bool connect_requested_;
+  IceRole ice_role_;
+  uint64 tiebreaker_;
+  TransportProtocol protocol_;
+  IceMode remote_ice_mode_;
+  rtc::scoped_ptr<TransportDescription> local_description_;
+  rtc::scoped_ptr<TransportDescription> remote_description_;
+
+  ChannelMap channels_;
+  // Buffers the ready_candidates so that SignalCanidatesReady can
+  // provide them in multiples.
+  std::vector<Candidate> ready_candidates_;
+  // Protects changes to channels and messages
+  rtc::CriticalSection crit_;
+
+  DISALLOW_EVIL_CONSTRUCTORS(Transport);
+};
+
+// Extract a TransportProtocol from a TransportDescription.
+TransportProtocol TransportProtocolFromDescription(
+    const TransportDescription* desc);
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_TRANSPORT_H_
diff --git a/webrtc/p2p/base/transport_unittest.cc b/webrtc/p2p/base/transport_unittest.cc
new file mode 100644
index 0000000..abcf32c
--- /dev/null
+++ b/webrtc/p2p/base/transport_unittest.cc
@@ -0,0 +1,438 @@
+/*
+ *  Copyright 2011 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/constants.h"
+#include "webrtc/p2p/base/fakesession.h"
+#include "webrtc/p2p/base/p2ptransport.h"
+#include "webrtc/p2p/base/parsing.h"
+#include "webrtc/p2p/base/rawtransport.h"
+#include "webrtc/p2p/base/sessionmessages.h"
+#include "webrtc/libjingle/xmllite/xmlelement.h"
+#include "webrtc/libjingle/xmpp/constants.h"
+#include "webrtc/base/fakesslidentity.h"
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/thread.h"
+
+using cricket::Candidate;
+using cricket::Candidates;
+using cricket::Transport;
+using cricket::FakeTransport;
+using cricket::TransportChannel;
+using cricket::FakeTransportChannel;
+using cricket::IceRole;
+using cricket::TransportDescription;
+using cricket::WriteError;
+using cricket::ParseError;
+using rtc::SocketAddress;
+
+static const char kIceUfrag1[] = "TESTICEUFRAG0001";
+static const char kIcePwd1[] = "TESTICEPWD00000000000001";
+
+static const char kIceUfrag2[] = "TESTICEUFRAG0002";
+static const char kIcePwd2[] = "TESTICEPWD00000000000002";
+
+class TransportTest : public testing::Test,
+                      public sigslot::has_slots<> {
+ public:
+  TransportTest()
+      : thread_(rtc::Thread::Current()),
+        transport_(new FakeTransport(
+            thread_, thread_, "test content name", NULL)),
+        channel_(NULL),
+        connecting_signalled_(false),
+        completed_(false),
+        failed_(false) {
+    transport_->SignalConnecting.connect(this, &TransportTest::OnConnecting);
+    transport_->SignalCompleted.connect(this, &TransportTest::OnCompleted);
+    transport_->SignalFailed.connect(this, &TransportTest::OnFailed);
+  }
+  ~TransportTest() {
+    transport_->DestroyAllChannels();
+  }
+  bool SetupChannel() {
+    channel_ = CreateChannel(1);
+    return (channel_ != NULL);
+  }
+  FakeTransportChannel* CreateChannel(int component) {
+    return static_cast<FakeTransportChannel*>(
+        transport_->CreateChannel(component));
+  }
+  void DestroyChannel() {
+    transport_->DestroyChannel(1);
+    channel_ = NULL;
+  }
+
+ protected:
+  void OnConnecting(Transport* transport) {
+    connecting_signalled_ = true;
+  }
+  void OnCompleted(Transport* transport) {
+    completed_ = true;
+  }
+  void OnFailed(Transport* transport) {
+    failed_ = true;
+  }
+
+  rtc::Thread* thread_;
+  rtc::scoped_ptr<FakeTransport> transport_;
+  FakeTransportChannel* channel_;
+  bool connecting_signalled_;
+  bool completed_;
+  bool failed_;
+};
+
+class FakeCandidateTranslator : public cricket::CandidateTranslator {
+ public:
+  void AddMapping(int component, const std::string& channel_name) {
+    name_to_component[channel_name] = component;
+    component_to_name[component] = channel_name;
+  }
+
+  bool GetChannelNameFromComponent(
+      int component, std::string* channel_name) const {
+    if (component_to_name.find(component) == component_to_name.end()) {
+      return false;
+    }
+    *channel_name = component_to_name.find(component)->second;
+    return true;
+  }
+  bool GetComponentFromChannelName(
+      const std::string& channel_name, int* component) const {
+    if (name_to_component.find(channel_name) == name_to_component.end()) {
+      return false;
+    }
+    *component = name_to_component.find(channel_name)->second;
+    return true;
+  }
+
+  std::map<std::string, int> name_to_component;
+  std::map<int, std::string> component_to_name;
+};
+
+// Test that calling ConnectChannels triggers an OnConnecting signal.
+TEST_F(TransportTest, TestConnectChannelsDoesSignal) {
+  EXPECT_TRUE(SetupChannel());
+  transport_->ConnectChannels();
+  EXPECT_FALSE(connecting_signalled_);
+
+  EXPECT_TRUE_WAIT(connecting_signalled_, 100);
+}
+
+// Test that DestroyAllChannels kills any pending OnConnecting signals.
+TEST_F(TransportTest, TestDestroyAllClearsPosts) {
+  EXPECT_TRUE(transport_->CreateChannel(1) != NULL);
+
+  transport_->ConnectChannels();
+  transport_->DestroyAllChannels();
+
+  thread_->ProcessMessages(0);
+  EXPECT_FALSE(connecting_signalled_);
+}
+
+// This test verifies channels are created with proper ICE
+// role, tiebreaker and remote ice mode and credentials after offer and
+// answer negotiations.
+TEST_F(TransportTest, TestChannelIceParameters) {
+  transport_->SetIceRole(cricket::ICEROLE_CONTROLLING);
+  transport_->SetIceTiebreaker(99U);
+  cricket::TransportDescription local_desc(
+      cricket::NS_JINGLE_ICE_UDP, kIceUfrag1, kIcePwd1);
+  ASSERT_TRUE(transport_->SetLocalTransportDescription(local_desc,
+                                                       cricket::CA_OFFER,
+                                                       NULL));
+  EXPECT_EQ(cricket::ICEROLE_CONTROLLING, transport_->ice_role());
+  EXPECT_TRUE(SetupChannel());
+  EXPECT_EQ(cricket::ICEROLE_CONTROLLING, channel_->GetIceRole());
+  EXPECT_EQ(cricket::ICEMODE_FULL, channel_->remote_ice_mode());
+  EXPECT_EQ(kIceUfrag1, channel_->ice_ufrag());
+  EXPECT_EQ(kIcePwd1, channel_->ice_pwd());
+
+  cricket::TransportDescription remote_desc(
+      cricket::NS_JINGLE_ICE_UDP, kIceUfrag1, kIcePwd1);
+  ASSERT_TRUE(transport_->SetRemoteTransportDescription(remote_desc,
+                                                        cricket::CA_ANSWER,
+                                                        NULL));
+  EXPECT_EQ(cricket::ICEROLE_CONTROLLING, channel_->GetIceRole());
+  EXPECT_EQ(99U, channel_->IceTiebreaker());
+  EXPECT_EQ(cricket::ICEMODE_FULL, channel_->remote_ice_mode());
+  // Changing the transport role from CONTROLLING to CONTROLLED.
+  transport_->SetIceRole(cricket::ICEROLE_CONTROLLED);
+  EXPECT_EQ(cricket::ICEROLE_CONTROLLED, channel_->GetIceRole());
+  EXPECT_EQ(cricket::ICEMODE_FULL, channel_->remote_ice_mode());
+  EXPECT_EQ(kIceUfrag1, channel_->remote_ice_ufrag());
+  EXPECT_EQ(kIcePwd1, channel_->remote_ice_pwd());
+}
+
+// Verifies that IceCredentialsChanged returns true when either ufrag or pwd
+// changed, and false in other cases.
+TEST_F(TransportTest, TestIceCredentialsChanged) {
+  EXPECT_TRUE(cricket::IceCredentialsChanged("u1", "p1", "u2", "p2"));
+  EXPECT_TRUE(cricket::IceCredentialsChanged("u1", "p1", "u2", "p1"));
+  EXPECT_TRUE(cricket::IceCredentialsChanged("u1", "p1", "u1", "p2"));
+  EXPECT_FALSE(cricket::IceCredentialsChanged("u1", "p1", "u1", "p1"));
+}
+
+// This test verifies that the callee's ICE role changes from controlled to
+// controlling when the callee triggers an ICE restart.
+TEST_F(TransportTest, TestIceControlledToControllingOnIceRestart) {
+  EXPECT_TRUE(SetupChannel());
+  transport_->SetIceRole(cricket::ICEROLE_CONTROLLED);
+
+  cricket::TransportDescription desc(
+      cricket::NS_JINGLE_ICE_UDP, kIceUfrag1, kIcePwd1);
+  ASSERT_TRUE(transport_->SetRemoteTransportDescription(desc,
+                                                        cricket::CA_OFFER,
+                                                        NULL));
+  ASSERT_TRUE(transport_->SetLocalTransportDescription(desc,
+                                                       cricket::CA_ANSWER,
+                                                       NULL));
+  EXPECT_EQ(cricket::ICEROLE_CONTROLLED, transport_->ice_role());
+
+  cricket::TransportDescription new_local_desc(
+      cricket::NS_JINGLE_ICE_UDP, kIceUfrag2, kIcePwd2);
+  ASSERT_TRUE(transport_->SetLocalTransportDescription(new_local_desc,
+                                                       cricket::CA_OFFER,
+                                                       NULL));
+  EXPECT_EQ(cricket::ICEROLE_CONTROLLING, transport_->ice_role());
+  EXPECT_EQ(cricket::ICEROLE_CONTROLLING, channel_->GetIceRole());
+}
+
+// This test verifies that the caller's ICE role changes from controlling to
+// controlled when the callee triggers an ICE restart.
+TEST_F(TransportTest, TestIceControllingToControlledOnIceRestart) {
+  EXPECT_TRUE(SetupChannel());
+  transport_->SetIceRole(cricket::ICEROLE_CONTROLLING);
+
+  cricket::TransportDescription desc(
+      cricket::NS_JINGLE_ICE_UDP, kIceUfrag1, kIcePwd1);
+  ASSERT_TRUE(transport_->SetLocalTransportDescription(desc,
+                                                       cricket::CA_OFFER,
+                                                       NULL));
+  ASSERT_TRUE(transport_->SetRemoteTransportDescription(desc,
+                                                        cricket::CA_ANSWER,
+                                                        NULL));
+  EXPECT_EQ(cricket::ICEROLE_CONTROLLING, transport_->ice_role());
+
+  cricket::TransportDescription new_local_desc(
+      cricket::NS_JINGLE_ICE_UDP, kIceUfrag2, kIcePwd2);
+  ASSERT_TRUE(transport_->SetLocalTransportDescription(new_local_desc,
+                                                       cricket::CA_ANSWER,
+                                                       NULL));
+  EXPECT_EQ(cricket::ICEROLE_CONTROLLED, transport_->ice_role());
+  EXPECT_EQ(cricket::ICEROLE_CONTROLLED, channel_->GetIceRole());
+}
+
+// This test verifies that the caller's ICE role is still controlling after the
+// callee triggers ICE restart if the callee's ICE mode is LITE.
+TEST_F(TransportTest, TestIceControllingOnIceRestartIfRemoteIsIceLite) {
+  EXPECT_TRUE(SetupChannel());
+  transport_->SetIceRole(cricket::ICEROLE_CONTROLLING);
+
+  cricket::TransportDescription desc(
+      cricket::NS_JINGLE_ICE_UDP, kIceUfrag1, kIcePwd1);
+  ASSERT_TRUE(transport_->SetLocalTransportDescription(desc,
+                                                       cricket::CA_OFFER,
+                                                       NULL));
+
+  cricket::TransportDescription remote_desc(
+      cricket::NS_JINGLE_ICE_UDP, std::vector<std::string>(),
+      kIceUfrag1, kIcePwd1, cricket::ICEMODE_LITE,
+      cricket::CONNECTIONROLE_NONE, NULL, cricket::Candidates());
+  ASSERT_TRUE(transport_->SetRemoteTransportDescription(remote_desc,
+                                                        cricket::CA_ANSWER,
+                                                        NULL));
+
+  EXPECT_EQ(cricket::ICEROLE_CONTROLLING, transport_->ice_role());
+
+  cricket::TransportDescription new_local_desc(
+      cricket::NS_JINGLE_ICE_UDP, kIceUfrag2, kIcePwd2);
+  ASSERT_TRUE(transport_->SetLocalTransportDescription(new_local_desc,
+                                                       cricket::CA_ANSWER,
+                                                       NULL));
+  EXPECT_EQ(cricket::ICEROLE_CONTROLLING, transport_->ice_role());
+  EXPECT_EQ(cricket::ICEROLE_CONTROLLING, channel_->GetIceRole());
+}
+
+// This test verifies that the Completed and Failed states can be reached.
+TEST_F(TransportTest, TestChannelCompletedAndFailed) {
+  transport_->SetIceRole(cricket::ICEROLE_CONTROLLING);
+  cricket::TransportDescription local_desc(
+      cricket::NS_JINGLE_ICE_UDP, kIceUfrag1, kIcePwd1);
+  ASSERT_TRUE(transport_->SetLocalTransportDescription(local_desc,
+                                                       cricket::CA_OFFER,
+                                                       NULL));
+  EXPECT_TRUE(SetupChannel());
+
+  cricket::TransportDescription remote_desc(
+      cricket::NS_JINGLE_ICE_UDP, kIceUfrag1, kIcePwd1);
+  ASSERT_TRUE(transport_->SetRemoteTransportDescription(remote_desc,
+                                                        cricket::CA_ANSWER,
+                                                        NULL));
+
+  channel_->SetConnectionCount(2);
+  channel_->SignalCandidatesAllocationDone(channel_);
+  channel_->SetWritable(true);
+  EXPECT_TRUE_WAIT(transport_->all_channels_writable(), 100);
+  // ICE is not yet completed because there is still more than one connection.
+  EXPECT_FALSE(completed_);
+  EXPECT_FALSE(failed_);
+
+  // When the connection count drops to 1, SignalCompleted should be emitted,
+  // and completed() should be true.
+  channel_->SetConnectionCount(1);
+  EXPECT_TRUE_WAIT(completed_, 100);
+  completed_ = false;
+
+  // When the connection count drops to 0, SignalFailed should be emitted, and
+  // completed() should be false.
+  channel_->SetConnectionCount(0);
+  EXPECT_TRUE_WAIT(failed_, 100);
+  EXPECT_FALSE(completed_);
+}
+
+// Tests channel role is reversed after receiving ice-lite from remote.
+TEST_F(TransportTest, TestSetRemoteIceLiteInOffer) {
+  transport_->SetIceRole(cricket::ICEROLE_CONTROLLED);
+  cricket::TransportDescription remote_desc(
+      cricket::NS_JINGLE_ICE_UDP, std::vector<std::string>(),
+      kIceUfrag1, kIcePwd1, cricket::ICEMODE_LITE,
+      cricket::CONNECTIONROLE_ACTPASS, NULL, cricket::Candidates());
+  ASSERT_TRUE(transport_->SetRemoteTransportDescription(remote_desc,
+                                                        cricket::CA_OFFER,
+                                                        NULL));
+  cricket::TransportDescription local_desc(
+      cricket::NS_JINGLE_ICE_UDP, kIceUfrag1, kIcePwd1);
+  ASSERT_TRUE(transport_->SetLocalTransportDescription(local_desc,
+                                                       cricket::CA_ANSWER,
+                                                       NULL));
+  EXPECT_EQ(cricket::ICEROLE_CONTROLLING, transport_->ice_role());
+  EXPECT_TRUE(SetupChannel());
+  EXPECT_EQ(cricket::ICEROLE_CONTROLLING, channel_->GetIceRole());
+  EXPECT_EQ(cricket::ICEMODE_LITE, channel_->remote_ice_mode());
+}
+
+// Tests ice-lite in remote answer.
+TEST_F(TransportTest, TestSetRemoteIceLiteInAnswer) {
+  transport_->SetIceRole(cricket::ICEROLE_CONTROLLING);
+  cricket::TransportDescription local_desc(
+      cricket::NS_JINGLE_ICE_UDP, kIceUfrag1, kIcePwd1);
+  ASSERT_TRUE(transport_->SetLocalTransportDescription(local_desc,
+                                                       cricket::CA_OFFER,
+                                                       NULL));
+  EXPECT_EQ(cricket::ICEROLE_CONTROLLING, transport_->ice_role());
+  EXPECT_TRUE(SetupChannel());
+  EXPECT_EQ(cricket::ICEROLE_CONTROLLING, channel_->GetIceRole());
+  // Channels will be created in ICEFULL_MODE.
+  EXPECT_EQ(cricket::ICEMODE_FULL, channel_->remote_ice_mode());
+  cricket::TransportDescription remote_desc(
+      cricket::NS_JINGLE_ICE_UDP, std::vector<std::string>(),
+      kIceUfrag1, kIcePwd1, cricket::ICEMODE_LITE,
+      cricket::CONNECTIONROLE_NONE, NULL, cricket::Candidates());
+  ASSERT_TRUE(transport_->SetRemoteTransportDescription(remote_desc,
+                                                        cricket::CA_ANSWER,
+                                                        NULL));
+  EXPECT_EQ(cricket::ICEROLE_CONTROLLING, channel_->GetIceRole());
+  // After receiving remote description with ICEMODE_LITE, channel should
+  // have mode set to ICEMODE_LITE.
+  EXPECT_EQ(cricket::ICEMODE_LITE, channel_->remote_ice_mode());
+}
+
+// Tests that we can properly serialize/deserialize candidates.
+TEST_F(TransportTest, TestP2PTransportWriteAndParseCandidate) {
+  Candidate test_candidate(
+      "", 1, "udp",
+      rtc::SocketAddress("2001:db8:fefe::1", 9999),
+      738197504, "abcdef", "ghijkl", "foo", "testnet", 50, "");
+  Candidate test_candidate2(
+      "", 2, "tcp",
+      rtc::SocketAddress("192.168.7.1", 9999),
+      1107296256, "mnopqr", "stuvwx", "bar", "testnet2", 100, "");
+  rtc::SocketAddress host_address("www.google.com", 24601);
+  host_address.SetResolvedIP(rtc::IPAddress(0x0A000001));
+  Candidate test_candidate3(
+      "", 3, "spdy", host_address, 1476395008, "yzabcd",
+      "efghij", "baz", "testnet3", 150, "");
+  WriteError write_error;
+  ParseError parse_error;
+  rtc::scoped_ptr<buzz::XmlElement> elem;
+  cricket::Candidate parsed_candidate;
+  cricket::P2PTransportParser parser;
+
+  FakeCandidateTranslator translator;
+  translator.AddMapping(1, "test");
+  translator.AddMapping(2, "test2");
+  translator.AddMapping(3, "test3");
+
+  EXPECT_TRUE(parser.WriteGingleCandidate(test_candidate, &translator,
+                                          elem.accept(), &write_error));
+  EXPECT_EQ("", write_error.text);
+  EXPECT_EQ("test", elem->Attr(buzz::QN_NAME));
+  EXPECT_EQ("udp", elem->Attr(cricket::QN_PROTOCOL));
+  EXPECT_EQ("2001:db8:fefe::1", elem->Attr(cricket::QN_ADDRESS));
+  EXPECT_EQ("9999", elem->Attr(cricket::QN_PORT));
+  EXPECT_EQ("0.34", elem->Attr(cricket::QN_PREFERENCE));
+  EXPECT_EQ("abcdef", elem->Attr(cricket::QN_USERNAME));
+  EXPECT_EQ("ghijkl", elem->Attr(cricket::QN_PASSWORD));
+  EXPECT_EQ("foo", elem->Attr(cricket::QN_TYPE));
+  EXPECT_EQ("testnet", elem->Attr(cricket::QN_NETWORK));
+  EXPECT_EQ("50", elem->Attr(cricket::QN_GENERATION));
+
+  EXPECT_TRUE(parser.ParseGingleCandidate(elem.get(), &translator,
+                                          &parsed_candidate, &parse_error));
+  EXPECT_TRUE(test_candidate.IsEquivalent(parsed_candidate));
+
+  EXPECT_TRUE(parser.WriteGingleCandidate(test_candidate2, &translator,
+                                          elem.accept(), &write_error));
+  EXPECT_EQ("test2", elem->Attr(buzz::QN_NAME));
+  EXPECT_EQ("tcp", elem->Attr(cricket::QN_PROTOCOL));
+  EXPECT_EQ("192.168.7.1", elem->Attr(cricket::QN_ADDRESS));
+  EXPECT_EQ("9999", elem->Attr(cricket::QN_PORT));
+  EXPECT_EQ("0.51", elem->Attr(cricket::QN_PREFERENCE));
+  EXPECT_EQ("mnopqr", elem->Attr(cricket::QN_USERNAME));
+  EXPECT_EQ("stuvwx", elem->Attr(cricket::QN_PASSWORD));
+  EXPECT_EQ("bar", elem->Attr(cricket::QN_TYPE));
+  EXPECT_EQ("testnet2", elem->Attr(cricket::QN_NETWORK));
+  EXPECT_EQ("100", elem->Attr(cricket::QN_GENERATION));
+
+  EXPECT_TRUE(parser.ParseGingleCandidate(elem.get(), &translator,
+                                          &parsed_candidate, &parse_error));
+  EXPECT_TRUE(test_candidate2.IsEquivalent(parsed_candidate));
+
+  // Check that an ip is preferred over hostname.
+  EXPECT_TRUE(parser.WriteGingleCandidate(test_candidate3, &translator,
+                                          elem.accept(), &write_error));
+  EXPECT_EQ("test3", elem->Attr(cricket::QN_NAME));
+  EXPECT_EQ("spdy", elem->Attr(cricket::QN_PROTOCOL));
+  EXPECT_EQ("10.0.0.1", elem->Attr(cricket::QN_ADDRESS));
+  EXPECT_EQ("24601", elem->Attr(cricket::QN_PORT));
+  EXPECT_EQ("0.69", elem->Attr(cricket::QN_PREFERENCE));
+  EXPECT_EQ("yzabcd", elem->Attr(cricket::QN_USERNAME));
+  EXPECT_EQ("efghij", elem->Attr(cricket::QN_PASSWORD));
+  EXPECT_EQ("baz", elem->Attr(cricket::QN_TYPE));
+  EXPECT_EQ("testnet3", elem->Attr(cricket::QN_NETWORK));
+  EXPECT_EQ("150", elem->Attr(cricket::QN_GENERATION));
+
+  EXPECT_TRUE(parser.ParseGingleCandidate(elem.get(), &translator,
+                                          &parsed_candidate, &parse_error));
+  EXPECT_TRUE(test_candidate3.IsEquivalent(parsed_candidate));
+}
+
+TEST_F(TransportTest, TestGetStats) {
+  EXPECT_TRUE(SetupChannel());
+  cricket::TransportStats stats;
+  EXPECT_TRUE(transport_->GetStats(&stats));
+  // Note that this tests the behavior of a FakeTransportChannel.
+  ASSERT_EQ(1U, stats.channel_stats.size());
+  EXPECT_EQ(1, stats.channel_stats[0].component);
+  transport_->ConnectChannels();
+  EXPECT_TRUE(transport_->GetStats(&stats));
+  ASSERT_EQ(1U, stats.channel_stats.size());
+  EXPECT_EQ(1, stats.channel_stats[0].component);
+}
diff --git a/webrtc/p2p/base/transportchannel.cc b/webrtc/p2p/base/transportchannel.cc
new file mode 100644
index 0000000..16ae27d
--- /dev/null
+++ b/webrtc/p2p/base/transportchannel.cc
@@ -0,0 +1,43 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <sstream>
+#include "webrtc/p2p/base/transportchannel.h"
+
+namespace cricket {
+
+std::string TransportChannel::ToString() const {
+  const char READABLE_ABBREV[2] = { '_', 'R' };
+  const char WRITABLE_ABBREV[2] = { '_', 'W' };
+  std::stringstream ss;
+  ss << "Channel[" << content_name_
+     << "|" << component_
+     << "|" << READABLE_ABBREV[readable_] << WRITABLE_ABBREV[writable_] << "]";
+  return ss.str();
+}
+
+void TransportChannel::set_readable(bool readable) {
+  if (readable_ != readable) {
+    readable_ = readable;
+    SignalReadableState(this);
+  }
+}
+
+void TransportChannel::set_writable(bool writable) {
+  if (writable_ != writable) {
+    writable_ = writable;
+    if (writable_) {
+      SignalReadyToSend(this);
+    }
+    SignalWritableState(this);
+  }
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/transportchannel.h b/webrtc/p2p/base/transportchannel.h
new file mode 100644
index 0000000..f91c4a8
--- /dev/null
+++ b/webrtc/p2p/base/transportchannel.h
@@ -0,0 +1,143 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_TRANSPORTCHANNEL_H_
+#define WEBRTC_P2P_BASE_TRANSPORTCHANNEL_H_
+
+#include <string>
+#include <vector>
+
+#include "webrtc/p2p/base/candidate.h"
+#include "webrtc/p2p/base/transport.h"
+#include "webrtc/p2p/base/transportdescription.h"
+#include "webrtc/base/asyncpacketsocket.h"
+#include "webrtc/base/basictypes.h"
+#include "webrtc/base/dscp.h"
+#include "webrtc/base/sigslot.h"
+#include "webrtc/base/socket.h"
+#include "webrtc/base/sslidentity.h"
+#include "webrtc/base/sslstreamadapter.h"
+
+namespace cricket {
+
+class Candidate;
+
+// Flags for SendPacket/SignalReadPacket.
+enum PacketFlags {
+  PF_NORMAL       = 0x00,  // A normal packet.
+  PF_SRTP_BYPASS  = 0x01,  // An encrypted SRTP packet; bypass any additional
+                           // crypto provided by the transport (e.g. DTLS)
+};
+
+// A TransportChannel represents one logical stream of packets that are sent
+// between the two sides of a session.
+class TransportChannel : public sigslot::has_slots<> {
+ public:
+  explicit TransportChannel(const std::string& content_name, int component)
+      : content_name_(content_name),
+        component_(component),
+        readable_(false), writable_(false) {}
+  virtual ~TransportChannel() {}
+
+  // TODO(mallinath) - Remove this API, as it's no longer useful.
+  // Returns the session id of this channel.
+  virtual const std::string SessionId() const { return std::string(); }
+
+  const std::string& content_name() const { return content_name_; }
+  int component() const { return component_; }
+
+  // Returns the readable and states of this channel.  Each time one of these
+  // states changes, a signal is raised.  These states are aggregated by the
+  // TransportManager.
+  bool readable() const { return readable_; }
+  bool writable() const { return writable_; }
+  sigslot::signal1<TransportChannel*> SignalReadableState;
+  sigslot::signal1<TransportChannel*> SignalWritableState;
+  // Emitted when the TransportChannel's ability to send has changed.
+  sigslot::signal1<TransportChannel*> SignalReadyToSend;
+
+  // Attempts to send the given packet.  The return value is < 0 on failure.
+  // TODO: Remove the default argument once channel code is updated.
+  virtual int SendPacket(const char* data, size_t len,
+                         const rtc::PacketOptions& options,
+                         int flags = 0) = 0;
+
+  // Sets a socket option on this channel.  Note that not all options are
+  // supported by all transport types.
+  virtual int SetOption(rtc::Socket::Option opt, int value) = 0;
+
+  // Returns the most recent error that occurred on this channel.
+  virtual int GetError() = 0;
+
+  // Returns the current stats for this connection.
+  virtual bool GetStats(ConnectionInfos* infos) = 0;
+
+  // Is DTLS active?
+  virtual bool IsDtlsActive() const = 0;
+
+  // Default implementation.
+  virtual bool GetSslRole(rtc::SSLRole* role) const = 0;
+
+  // Sets up the ciphers to use for DTLS-SRTP.
+  virtual bool SetSrtpCiphers(const std::vector<std::string>& ciphers) = 0;
+
+  // Finds out which DTLS-SRTP cipher was negotiated
+  virtual bool GetSrtpCipher(std::string* cipher) = 0;
+
+  // Gets a copy of the local SSL identity, owned by the caller.
+  virtual bool GetLocalIdentity(rtc::SSLIdentity** identity) const = 0;
+
+  // Gets a copy of the remote side's SSL certificate, owned by the caller.
+  virtual bool GetRemoteCertificate(rtc::SSLCertificate** cert) const = 0;
+
+  // Allows key material to be extracted for external encryption.
+  virtual bool ExportKeyingMaterial(const std::string& label,
+      const uint8* context,
+      size_t context_len,
+      bool use_context,
+      uint8* result,
+      size_t result_len) = 0;
+
+  // Signalled each time a packet is received on this channel.
+  sigslot::signal5<TransportChannel*, const char*,
+                   size_t, const rtc::PacketTime&, int> SignalReadPacket;
+
+  // This signal occurs when there is a change in the way that packets are
+  // being routed, i.e. to a different remote location. The candidate
+  // indicates where and how we are currently sending media.
+  sigslot::signal2<TransportChannel*, const Candidate&> SignalRouteChange;
+
+  // Invoked when the channel is being destroyed.
+  sigslot::signal1<TransportChannel*> SignalDestroyed;
+
+  // Debugging description of this transport channel.
+  std::string ToString() const;
+
+ protected:
+  // Sets the readable state, signaling if necessary.
+  void set_readable(bool readable);
+
+  // Sets the writable state, signaling if necessary.
+  void set_writable(bool writable);
+
+
+ private:
+  // Used mostly for debugging.
+  std::string content_name_;
+  int component_;
+  bool readable_;
+  bool writable_;
+
+  DISALLOW_EVIL_CONSTRUCTORS(TransportChannel);
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_TRANSPORTCHANNEL_H_
diff --git a/webrtc/p2p/base/transportchannelimpl.h b/webrtc/p2p/base/transportchannelimpl.h
new file mode 100644
index 0000000..060df7f
--- /dev/null
+++ b/webrtc/p2p/base/transportchannelimpl.h
@@ -0,0 +1,111 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_TRANSPORTCHANNELIMPL_H_
+#define WEBRTC_P2P_BASE_TRANSPORTCHANNELIMPL_H_
+
+#include <string>
+#include "webrtc/p2p/base/transport.h"
+#include "webrtc/p2p/base/transportchannel.h"
+
+namespace buzz { class XmlElement; }
+
+namespace cricket {
+
+class Candidate;
+
+// Base class for real implementations of TransportChannel.  This includes some
+// methods called only by Transport, which do not need to be exposed to the
+// client.
+class TransportChannelImpl : public TransportChannel {
+ public:
+  explicit TransportChannelImpl(const std::string& content_name, int component)
+      : TransportChannel(content_name, component) {}
+
+  // Returns the transport that created this channel.
+  virtual Transport* GetTransport() = 0;
+
+  // For ICE channels.
+  virtual IceRole GetIceRole() const = 0;
+  virtual void SetIceRole(IceRole role) = 0;
+  virtual void SetIceTiebreaker(uint64 tiebreaker) = 0;
+  virtual size_t GetConnectionCount() const = 0;
+  // To toggle G-ICE/ICE.
+  virtual bool GetIceProtocolType(IceProtocolType* type) const = 0;
+  virtual void SetIceProtocolType(IceProtocolType type) = 0;
+  // SetIceCredentials only need to be implemented by the ICE
+  // transport channels. Non-ICE transport channels can just ignore.
+  // The ufrag and pwd should be set before the Connect() is called.
+  virtual void SetIceCredentials(const std::string& ice_ufrag,
+                                 const std::string& ice_pwd)  = 0;
+  // SetRemoteIceCredentials only need to be implemented by the ICE
+  // transport channels. Non-ICE transport channels can just ignore.
+  virtual void SetRemoteIceCredentials(const std::string& ice_ufrag,
+                                       const std::string& ice_pwd) = 0;
+
+  // SetRemoteIceMode must be implemented only by the ICE transport channels.
+  virtual void SetRemoteIceMode(IceMode mode) = 0;
+
+  // Begins the process of attempting to make a connection to the other client.
+  virtual void Connect() = 0;
+
+  // Resets this channel back to the initial state (i.e., not connecting).
+  virtual void Reset() = 0;
+
+  // Allows an individual channel to request signaling and be notified when it
+  // is ready.  This is useful if the individual named channels have need to
+  // send their own transport-info stanzas.
+  sigslot::signal1<TransportChannelImpl*> SignalRequestSignaling;
+  virtual void OnSignalingReady() = 0;
+
+  // Handles sending and receiving of candidates.  The Transport
+  // receives the candidates and may forward them to the relevant
+  // channel.
+  //
+  // Note: Since candidates are delivered asynchronously to the
+  // channel, they cannot return an error if the message is invalid.
+  // It is assumed that the Transport will have checked validity
+  // before forwarding.
+  sigslot::signal2<TransportChannelImpl*,
+                   const Candidate&> SignalCandidateReady;
+  virtual void OnCandidate(const Candidate& candidate) = 0;
+
+  // DTLS methods
+  // Set DTLS local identity.  The identity object is not copied, but the caller
+  // retains ownership and must delete it after this TransportChannelImpl is
+  // destroyed.
+  // TODO(bemasc): Fix the ownership semantics of this method.
+  virtual bool SetLocalIdentity(rtc::SSLIdentity* identity) = 0;
+
+  // Set DTLS Remote fingerprint. Must be after local identity set.
+  virtual bool SetRemoteFingerprint(const std::string& digest_alg,
+    const uint8* digest,
+    size_t digest_len) = 0;
+
+  virtual bool SetSslRole(rtc::SSLRole role) = 0;
+
+  // TransportChannel is forwarding this signal from PortAllocatorSession.
+  sigslot::signal1<TransportChannelImpl*> SignalCandidatesAllocationDone;
+
+  // Invoked when there is conflict in the ICE role between local and remote
+  // agents.
+  sigslot::signal1<TransportChannelImpl*> SignalRoleConflict;
+
+  // Emitted whenever the number of connections available to the transport
+  // channel decreases.
+  sigslot::signal1<TransportChannelImpl*> SignalConnectionRemoved;
+
+ private:
+  DISALLOW_EVIL_CONSTRUCTORS(TransportChannelImpl);
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_TRANSPORTCHANNELIMPL_H_
diff --git a/webrtc/p2p/base/transportchannelproxy.cc b/webrtc/p2p/base/transportchannelproxy.cc
new file mode 100644
index 0000000..b5e0957
--- /dev/null
+++ b/webrtc/p2p/base/transportchannelproxy.cc
@@ -0,0 +1,249 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/transport.h"
+#include "webrtc/p2p/base/transportchannelimpl.h"
+#include "webrtc/p2p/base/transportchannelproxy.h"
+#include "webrtc/base/common.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/thread.h"
+
+namespace cricket {
+
+enum {
+  MSG_UPDATESTATE,
+};
+
+TransportChannelProxy::TransportChannelProxy(const std::string& content_name,
+                                             const std::string& name,
+                                             int component)
+    : TransportChannel(content_name, component),
+      name_(name),
+      impl_(NULL) {
+  worker_thread_ = rtc::Thread::Current();
+}
+
+TransportChannelProxy::~TransportChannelProxy() {
+  // Clearing any pending signal.
+  worker_thread_->Clear(this);
+  if (impl_)
+    impl_->GetTransport()->DestroyChannel(impl_->component());
+}
+
+void TransportChannelProxy::SetImplementation(TransportChannelImpl* impl) {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+
+  if (impl == impl_) {
+    // Ignore if the |impl| has already been set.
+    LOG(LS_WARNING) << "Ignored TransportChannelProxy::SetImplementation call "
+                    << "with a same impl as the existing one.";
+    return;
+  }
+
+  // Destroy any existing impl_.
+  if (impl_) {
+    impl_->GetTransport()->DestroyChannel(impl_->component());
+  }
+
+  // Adopt the supplied impl, and connect to its signals.
+  impl_ = impl;
+
+  if (impl_) {
+    impl_->SignalReadableState.connect(
+        this, &TransportChannelProxy::OnReadableState);
+    impl_->SignalWritableState.connect(
+        this, &TransportChannelProxy::OnWritableState);
+    impl_->SignalReadPacket.connect(
+        this, &TransportChannelProxy::OnReadPacket);
+    impl_->SignalReadyToSend.connect(
+        this, &TransportChannelProxy::OnReadyToSend);
+    impl_->SignalRouteChange.connect(
+        this, &TransportChannelProxy::OnRouteChange);
+    for (OptionList::iterator it = pending_options_.begin();
+         it != pending_options_.end();
+         ++it) {
+      impl_->SetOption(it->first, it->second);
+    }
+
+    // Push down the SRTP ciphers, if any were set.
+    if (!pending_srtp_ciphers_.empty()) {
+      impl_->SetSrtpCiphers(pending_srtp_ciphers_);
+    }
+    pending_options_.clear();
+  }
+
+  // Post ourselves a message to see if we need to fire state callbacks.
+  worker_thread_->Post(this, MSG_UPDATESTATE);
+}
+
+int TransportChannelProxy::SendPacket(const char* data, size_t len,
+                                      const rtc::PacketOptions& options,
+                                      int flags) {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  // Fail if we don't have an impl yet.
+  if (!impl_) {
+    return -1;
+  }
+  return impl_->SendPacket(data, len, options, flags);
+}
+
+int TransportChannelProxy::SetOption(rtc::Socket::Option opt, int value) {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  if (!impl_) {
+    pending_options_.push_back(OptionPair(opt, value));
+    return 0;
+  }
+  return impl_->SetOption(opt, value);
+}
+
+int TransportChannelProxy::GetError() {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  if (!impl_) {
+    return 0;
+  }
+  return impl_->GetError();
+}
+
+bool TransportChannelProxy::GetStats(ConnectionInfos* infos) {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  if (!impl_) {
+    return false;
+  }
+  return impl_->GetStats(infos);
+}
+
+bool TransportChannelProxy::IsDtlsActive() const {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  if (!impl_) {
+    return false;
+  }
+  return impl_->IsDtlsActive();
+}
+
+bool TransportChannelProxy::GetSslRole(rtc::SSLRole* role) const {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  if (!impl_) {
+    return false;
+  }
+  return impl_->GetSslRole(role);
+}
+
+bool TransportChannelProxy::SetSslRole(rtc::SSLRole role) {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  if (!impl_) {
+    return false;
+  }
+  return impl_->SetSslRole(role);
+}
+
+bool TransportChannelProxy::SetSrtpCiphers(const std::vector<std::string>&
+                                           ciphers) {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  pending_srtp_ciphers_ = ciphers;  // Cache so we can send later, but always
+                                    // set so it stays consistent.
+  if (impl_) {
+    return impl_->SetSrtpCiphers(ciphers);
+  }
+  return true;
+}
+
+bool TransportChannelProxy::GetSrtpCipher(std::string* cipher) {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  if (!impl_) {
+    return false;
+  }
+  return impl_->GetSrtpCipher(cipher);
+}
+
+bool TransportChannelProxy::GetLocalIdentity(
+    rtc::SSLIdentity** identity) const {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  if (!impl_) {
+    return false;
+  }
+  return impl_->GetLocalIdentity(identity);
+}
+
+bool TransportChannelProxy::GetRemoteCertificate(
+    rtc::SSLCertificate** cert) const {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  if (!impl_) {
+    return false;
+  }
+  return impl_->GetRemoteCertificate(cert);
+}
+
+bool TransportChannelProxy::ExportKeyingMaterial(const std::string& label,
+                                                 const uint8* context,
+                                                 size_t context_len,
+                                                 bool use_context,
+                                                 uint8* result,
+                                                 size_t result_len) {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  if (!impl_) {
+    return false;
+  }
+  return impl_->ExportKeyingMaterial(label, context, context_len, use_context,
+                                     result, result_len);
+}
+
+IceRole TransportChannelProxy::GetIceRole() const {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  if (!impl_) {
+    return ICEROLE_UNKNOWN;
+  }
+  return impl_->GetIceRole();
+}
+
+void TransportChannelProxy::OnReadableState(TransportChannel* channel) {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  ASSERT(channel == impl_);
+  set_readable(impl_->readable());
+  // Note: SignalReadableState fired by set_readable.
+}
+
+void TransportChannelProxy::OnWritableState(TransportChannel* channel) {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  ASSERT(channel == impl_);
+  set_writable(impl_->writable());
+  // Note: SignalWritableState fired by set_readable.
+}
+
+void TransportChannelProxy::OnReadPacket(
+    TransportChannel* channel, const char* data, size_t size,
+    const rtc::PacketTime& packet_time, int flags) {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  ASSERT(channel == impl_);
+  SignalReadPacket(this, data, size, packet_time, flags);
+}
+
+void TransportChannelProxy::OnReadyToSend(TransportChannel* channel) {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  ASSERT(channel == impl_);
+  SignalReadyToSend(this);
+}
+
+void TransportChannelProxy::OnRouteChange(TransportChannel* channel,
+                                          const Candidate& candidate) {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  ASSERT(channel == impl_);
+  SignalRouteChange(this, candidate);
+}
+
+void TransportChannelProxy::OnMessage(rtc::Message* msg) {
+  ASSERT(rtc::Thread::Current() == worker_thread_);
+  if (msg->message_id == MSG_UPDATESTATE) {
+     // If impl_ is already readable or writable, push up those signals.
+     set_readable(impl_ ? impl_->readable() : false);
+     set_writable(impl_ ? impl_->writable() : false);
+  }
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/transportchannelproxy.h b/webrtc/p2p/base/transportchannelproxy.h
new file mode 100644
index 0000000..cfd07f8
--- /dev/null
+++ b/webrtc/p2p/base/transportchannelproxy.h
@@ -0,0 +1,95 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_TRANSPORTCHANNELPROXY_H_
+#define WEBRTC_P2P_BASE_TRANSPORTCHANNELPROXY_H_
+
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "webrtc/p2p/base/transportchannel.h"
+#include "webrtc/base/messagehandler.h"
+
+namespace rtc {
+class Thread;
+}
+
+namespace cricket {
+
+class TransportChannelImpl;
+
+// Proxies calls between the client and the transport channel implementation.
+// This is needed because clients are allowed to create channels before the
+// network negotiation is complete.  Hence, we create a proxy up front, and
+// when negotiation completes, connect the proxy to the implementaiton.
+class TransportChannelProxy : public TransportChannel,
+                              public rtc::MessageHandler {
+ public:
+  TransportChannelProxy(const std::string& content_name,
+                        const std::string& name,
+                        int component);
+  virtual ~TransportChannelProxy();
+
+  const std::string& name() const { return name_; }
+  TransportChannelImpl* impl() { return impl_; }
+
+  // Sets the implementation to which we will proxy.
+  void SetImplementation(TransportChannelImpl* impl);
+
+  // Implementation of the TransportChannel interface.  These simply forward to
+  // the implementation.
+  virtual int SendPacket(const char* data, size_t len,
+                         const rtc::PacketOptions& options,
+                         int flags);
+  virtual int SetOption(rtc::Socket::Option opt, int value);
+  virtual int GetError();
+  virtual IceRole GetIceRole() const;
+  virtual bool GetStats(ConnectionInfos* infos);
+  virtual bool IsDtlsActive() const;
+  virtual bool GetSslRole(rtc::SSLRole* role) const;
+  virtual bool SetSslRole(rtc::SSLRole role);
+  virtual bool SetSrtpCiphers(const std::vector<std::string>& ciphers);
+  virtual bool GetSrtpCipher(std::string* cipher);
+  virtual bool GetLocalIdentity(rtc::SSLIdentity** identity) const;
+  virtual bool GetRemoteCertificate(rtc::SSLCertificate** cert) const;
+  virtual bool ExportKeyingMaterial(const std::string& label,
+                            const uint8* context,
+                            size_t context_len,
+                            bool use_context,
+                            uint8* result,
+                            size_t result_len);
+
+ private:
+  // Catch signals from the implementation channel.  These just forward to the
+  // client (after updating our state to match).
+  void OnReadableState(TransportChannel* channel);
+  void OnWritableState(TransportChannel* channel);
+  void OnReadPacket(TransportChannel* channel, const char* data, size_t size,
+                    const rtc::PacketTime& packet_time, int flags);
+  void OnReadyToSend(TransportChannel* channel);
+  void OnRouteChange(TransportChannel* channel, const Candidate& candidate);
+
+  void OnMessage(rtc::Message* message);
+
+  typedef std::pair<rtc::Socket::Option, int> OptionPair;
+  typedef std::vector<OptionPair> OptionList;
+  std::string name_;
+  rtc::Thread* worker_thread_;
+  TransportChannelImpl* impl_;
+  OptionList pending_options_;
+  std::vector<std::string> pending_srtp_ciphers_;
+
+  DISALLOW_EVIL_CONSTRUCTORS(TransportChannelProxy);
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_TRANSPORTCHANNELPROXY_H_
diff --git a/webrtc/p2p/base/transportdescription.cc b/webrtc/p2p/base/transportdescription.cc
new file mode 100644
index 0000000..01c6a8f
--- /dev/null
+++ b/webrtc/p2p/base/transportdescription.cc
@@ -0,0 +1,55 @@
+/*
+ *  Copyright 2013 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/transportdescription.h"
+
+#include "webrtc/p2p/base/constants.h"
+#include "webrtc/base/stringutils.h"
+
+namespace cricket {
+
+bool StringToConnectionRole(const std::string& role_str, ConnectionRole* role) {
+  const char* const roles[] = {
+      CONNECTIONROLE_ACTIVE_STR,
+      CONNECTIONROLE_PASSIVE_STR,
+      CONNECTIONROLE_ACTPASS_STR,
+      CONNECTIONROLE_HOLDCONN_STR
+  };
+
+  for (size_t i = 0; i < ARRAY_SIZE(roles); ++i) {
+    if (_stricmp(roles[i], role_str.c_str()) == 0) {
+      *role = static_cast<ConnectionRole>(CONNECTIONROLE_ACTIVE + i);
+      return true;
+    }
+  }
+  return false;
+}
+
+bool ConnectionRoleToString(const ConnectionRole& role, std::string* role_str) {
+  switch (role) {
+    case cricket::CONNECTIONROLE_ACTIVE:
+      *role_str = cricket::CONNECTIONROLE_ACTIVE_STR;
+      break;
+    case cricket::CONNECTIONROLE_ACTPASS:
+      *role_str = cricket::CONNECTIONROLE_ACTPASS_STR;
+      break;
+    case cricket::CONNECTIONROLE_PASSIVE:
+      *role_str = cricket::CONNECTIONROLE_PASSIVE_STR;
+      break;
+    case cricket::CONNECTIONROLE_HOLDCONN:
+      *role_str = cricket::CONNECTIONROLE_HOLDCONN_STR;
+      break;
+    default:
+      return false;
+  }
+  return true;
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/transportdescription.h b/webrtc/p2p/base/transportdescription.h
new file mode 100644
index 0000000..5ab1cd6
--- /dev/null
+++ b/webrtc/p2p/base/transportdescription.h
@@ -0,0 +1,171 @@
+/*
+ *  Copyright 2012 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_TRANSPORTDESCRIPTION_H_
+#define WEBRTC_P2P_BASE_TRANSPORTDESCRIPTION_H_
+
+#include <algorithm>
+#include <string>
+#include <vector>
+
+#include "webrtc/p2p/base/candidate.h"
+#include "webrtc/p2p/base/constants.h"
+#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/sslfingerprint.h"
+
+namespace cricket {
+
+// SEC_ENABLED and SEC_REQUIRED should only be used if the session
+// was negotiated over TLS, to protect the inline crypto material
+// exchange.
+// SEC_DISABLED: No crypto in outgoing offer, ignore any supplied crypto.
+// SEC_ENABLED:  Crypto in outgoing offer and answer (if supplied in offer).
+// SEC_REQUIRED: Crypto in outgoing offer and answer. Fail any offer with absent
+//               or unsupported crypto.
+enum SecurePolicy {
+  SEC_DISABLED,
+  SEC_ENABLED,
+  SEC_REQUIRED
+};
+
+// The transport protocol we've elected to use.
+enum TransportProtocol {
+  ICEPROTO_GOOGLE,  // Google version of ICE protocol.
+  ICEPROTO_HYBRID,  // ICE, but can fall back to the Google version.
+  ICEPROTO_RFC5245  // Standard RFC 5245 version of ICE.
+};
+// The old name for TransportProtocol.
+// TODO(juberti): remove this.
+typedef TransportProtocol IceProtocolType;
+
+// Whether our side of the call is driving the negotiation, or the other side.
+enum IceRole {
+  ICEROLE_CONTROLLING = 0,
+  ICEROLE_CONTROLLED,
+  ICEROLE_UNKNOWN
+};
+
+// ICE RFC 5245 implementation type.
+enum IceMode {
+  ICEMODE_FULL,  // As defined in http://tools.ietf.org/html/rfc5245#section-4.1
+  ICEMODE_LITE   // As defined in http://tools.ietf.org/html/rfc5245#section-4.2
+};
+
+// RFC 4145 - http://tools.ietf.org/html/rfc4145#section-4
+// 'active':  The endpoint will initiate an outgoing connection.
+// 'passive': The endpoint will accept an incoming connection.
+// 'actpass': The endpoint is willing to accept an incoming
+//            connection or to initiate an outgoing connection.
+enum ConnectionRole {
+  CONNECTIONROLE_NONE = 0,
+  CONNECTIONROLE_ACTIVE,
+  CONNECTIONROLE_PASSIVE,
+  CONNECTIONROLE_ACTPASS,
+  CONNECTIONROLE_HOLDCONN,
+};
+
+extern const char CONNECTIONROLE_ACTIVE_STR[];
+extern const char CONNECTIONROLE_PASSIVE_STR[];
+extern const char CONNECTIONROLE_ACTPASS_STR[];
+extern const char CONNECTIONROLE_HOLDCONN_STR[];
+
+bool StringToConnectionRole(const std::string& role_str, ConnectionRole* role);
+bool ConnectionRoleToString(const ConnectionRole& role, std::string* role_str);
+
+typedef std::vector<Candidate> Candidates;
+
+struct TransportDescription {
+  TransportDescription()
+      : ice_mode(ICEMODE_FULL),
+        connection_role(CONNECTIONROLE_NONE) {}
+
+  TransportDescription(const std::string& transport_type,
+                       const std::vector<std::string>& transport_options,
+                       const std::string& ice_ufrag,
+                       const std::string& ice_pwd,
+                       IceMode ice_mode,
+                       ConnectionRole role,
+                       const rtc::SSLFingerprint* identity_fingerprint,
+                       const Candidates& candidates)
+      : transport_type(transport_type),
+        transport_options(transport_options),
+        ice_ufrag(ice_ufrag),
+        ice_pwd(ice_pwd),
+        ice_mode(ice_mode),
+        connection_role(role),
+        identity_fingerprint(CopyFingerprint(identity_fingerprint)),
+        candidates(candidates) {}
+  TransportDescription(const std::string& transport_type,
+                       const std::string& ice_ufrag,
+                       const std::string& ice_pwd)
+      : transport_type(transport_type),
+        ice_ufrag(ice_ufrag),
+        ice_pwd(ice_pwd),
+        ice_mode(ICEMODE_FULL),
+        connection_role(CONNECTIONROLE_NONE) {}
+  TransportDescription(const TransportDescription& from)
+      : transport_type(from.transport_type),
+        transport_options(from.transport_options),
+        ice_ufrag(from.ice_ufrag),
+        ice_pwd(from.ice_pwd),
+        ice_mode(from.ice_mode),
+        connection_role(from.connection_role),
+        identity_fingerprint(CopyFingerprint(from.identity_fingerprint.get())),
+        candidates(from.candidates) {}
+
+  TransportDescription& operator=(const TransportDescription& from) {
+    // Self-assignment
+    if (this == &from)
+      return *this;
+
+    transport_type = from.transport_type;
+    transport_options = from.transport_options;
+    ice_ufrag = from.ice_ufrag;
+    ice_pwd = from.ice_pwd;
+    ice_mode = from.ice_mode;
+    connection_role = from.connection_role;
+
+    identity_fingerprint.reset(CopyFingerprint(
+        from.identity_fingerprint.get()));
+    candidates = from.candidates;
+    return *this;
+  }
+
+  bool HasOption(const std::string& option) const {
+    return (std::find(transport_options.begin(), transport_options.end(),
+                      option) != transport_options.end());
+  }
+  void AddOption(const std::string& option) {
+    transport_options.push_back(option);
+  }
+  bool secure() const { return identity_fingerprint != NULL; }
+
+  static rtc::SSLFingerprint* CopyFingerprint(
+      const rtc::SSLFingerprint* from) {
+    if (!from)
+      return NULL;
+
+    return new rtc::SSLFingerprint(*from);
+  }
+
+  std::string transport_type;  // xmlns of <transport>
+  std::vector<std::string> transport_options;
+  std::string ice_ufrag;
+  std::string ice_pwd;
+  IceMode ice_mode;
+  ConnectionRole connection_role;
+
+  rtc::scoped_ptr<rtc::SSLFingerprint> identity_fingerprint;
+  Candidates candidates;
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_TRANSPORTDESCRIPTION_H_
diff --git a/webrtc/p2p/base/transportdescriptionfactory.cc b/webrtc/p2p/base/transportdescriptionfactory.cc
new file mode 100644
index 0000000..619c9d1
--- /dev/null
+++ b/webrtc/p2p/base/transportdescriptionfactory.cc
@@ -0,0 +1,160 @@
+/*
+ *  Copyright 2012 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/transportdescriptionfactory.h"
+
+#include "webrtc/p2p/base/transportdescription.h"
+#include "webrtc/base/helpers.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/messagedigest.h"
+#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/sslfingerprint.h"
+
+namespace cricket {
+
+static TransportProtocol kDefaultProtocol = ICEPROTO_GOOGLE;
+
+TransportDescriptionFactory::TransportDescriptionFactory()
+    : protocol_(kDefaultProtocol),
+      secure_(SEC_DISABLED),
+      identity_(NULL) {
+}
+
+TransportDescription* TransportDescriptionFactory::CreateOffer(
+    const TransportOptions& options,
+    const TransportDescription* current_description) const {
+  rtc::scoped_ptr<TransportDescription> desc(new TransportDescription());
+
+  // Set the transport type depending on the selected protocol.
+  if (protocol_ == ICEPROTO_RFC5245) {
+    desc->transport_type = NS_JINGLE_ICE_UDP;
+  } else if (protocol_ == ICEPROTO_HYBRID) {
+    desc->transport_type = NS_JINGLE_ICE_UDP;
+    desc->AddOption(ICE_OPTION_GICE);
+  } else if (protocol_ == ICEPROTO_GOOGLE) {
+    desc->transport_type = NS_GINGLE_P2P;
+  }
+
+  // Generate the ICE credentials if we don't already have them.
+  if (!current_description || options.ice_restart) {
+    desc->ice_ufrag = rtc::CreateRandomString(ICE_UFRAG_LENGTH);
+    desc->ice_pwd = rtc::CreateRandomString(ICE_PWD_LENGTH);
+  } else {
+    desc->ice_ufrag = current_description->ice_ufrag;
+    desc->ice_pwd = current_description->ice_pwd;
+  }
+
+  // If we are trying to establish a secure transport, add a fingerprint.
+  if (secure_ == SEC_ENABLED || secure_ == SEC_REQUIRED) {
+    // Fail if we can't create the fingerprint.
+    // If we are the initiator set role to "actpass".
+    if (!SetSecurityInfo(desc.get(), CONNECTIONROLE_ACTPASS)) {
+      return NULL;
+    }
+  }
+
+  return desc.release();
+}
+
+TransportDescription* TransportDescriptionFactory::CreateAnswer(
+    const TransportDescription* offer,
+    const TransportOptions& options,
+    const TransportDescription* current_description) const {
+  // A NULL offer is treated as a GICE transport description.
+  // TODO(juberti): Figure out why we get NULL offers, and fix this upstream.
+  rtc::scoped_ptr<TransportDescription> desc(new TransportDescription());
+
+  // Figure out which ICE variant to negotiate; prefer RFC 5245 ICE, but fall
+  // back to G-ICE if needed. Note that we never create a hybrid answer, since
+  // we know what the other side can support already.
+  if (offer && offer->transport_type == NS_JINGLE_ICE_UDP &&
+      (protocol_ == ICEPROTO_RFC5245 || protocol_ == ICEPROTO_HYBRID)) {
+    // Offer is ICE or hybrid, we support ICE or hybrid: use ICE.
+    desc->transport_type = NS_JINGLE_ICE_UDP;
+  } else if (offer && offer->transport_type == NS_JINGLE_ICE_UDP &&
+             offer->HasOption(ICE_OPTION_GICE) &&
+             protocol_ == ICEPROTO_GOOGLE) {
+    desc->transport_type = NS_GINGLE_P2P;
+    // Offer is hybrid, we support GICE: use GICE.
+  } else if ((!offer || offer->transport_type == NS_GINGLE_P2P) &&
+             (protocol_ == ICEPROTO_HYBRID || protocol_ == ICEPROTO_GOOGLE)) {
+    // Offer is GICE, we support hybrid or GICE: use GICE.
+    desc->transport_type = NS_GINGLE_P2P;
+  } else {
+    // Mismatch.
+    LOG(LS_WARNING) << "Failed to create TransportDescription answer "
+                       "because of incompatible transport types";
+    return NULL;
+  }
+
+  // Generate the ICE credentials if we don't already have them or ice is
+  // being restarted.
+  if (!current_description || options.ice_restart) {
+    desc->ice_ufrag = rtc::CreateRandomString(ICE_UFRAG_LENGTH);
+    desc->ice_pwd = rtc::CreateRandomString(ICE_PWD_LENGTH);
+  } else {
+    desc->ice_ufrag = current_description->ice_ufrag;
+    desc->ice_pwd = current_description->ice_pwd;
+  }
+
+  // Negotiate security params.
+  if (offer && offer->identity_fingerprint.get()) {
+    // The offer supports DTLS, so answer with DTLS, as long as we support it.
+    if (secure_ == SEC_ENABLED || secure_ == SEC_REQUIRED) {
+      // Fail if we can't create the fingerprint.
+      // Setting DTLS role to active.
+      ConnectionRole role = (options.prefer_passive_role) ?
+          CONNECTIONROLE_PASSIVE : CONNECTIONROLE_ACTIVE;
+
+      if (!SetSecurityInfo(desc.get(), role)) {
+        return NULL;
+      }
+    }
+  } else if (secure_ == SEC_REQUIRED) {
+    // We require DTLS, but the other side didn't offer it. Fail.
+    LOG(LS_WARNING) << "Failed to create TransportDescription answer "
+                       "because of incompatible security settings";
+    return NULL;
+  }
+
+  return desc.release();
+}
+
+bool TransportDescriptionFactory::SetSecurityInfo(
+    TransportDescription* desc, ConnectionRole role) const {
+  if (!identity_) {
+    LOG(LS_ERROR) << "Cannot create identity digest with no identity";
+    return false;
+  }
+
+  // This digest algorithm is used to produce the a=fingerprint lines in SDP.
+  // RFC 4572 Section 5 requires that those lines use the same hash function as
+  // the certificate's signature.
+  std::string digest_alg;
+  if (!identity_->certificate().GetSignatureDigestAlgorithm(&digest_alg)) {
+    LOG(LS_ERROR) << "Failed to retrieve the certificate's digest algorithm";
+    return false;
+  }
+
+  desc->identity_fingerprint.reset(
+      rtc::SSLFingerprint::Create(digest_alg, identity_));
+  if (!desc->identity_fingerprint.get()) {
+    LOG(LS_ERROR) << "Failed to create identity fingerprint, alg="
+                  << digest_alg;
+    return false;
+  }
+
+  // Assign security role.
+  desc->connection_role = role;
+  return true;
+}
+
+}  // namespace cricket
+
diff --git a/webrtc/p2p/base/transportdescriptionfactory.h b/webrtc/p2p/base/transportdescriptionfactory.h
new file mode 100644
index 0000000..a137f72
--- /dev/null
+++ b/webrtc/p2p/base/transportdescriptionfactory.h
@@ -0,0 +1,66 @@
+/*
+ *  Copyright 2012 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_TRANSPORTDESCRIPTIONFACTORY_H_
+#define WEBRTC_P2P_BASE_TRANSPORTDESCRIPTIONFACTORY_H_
+
+#include "webrtc/p2p/base/transportdescription.h"
+
+namespace rtc {
+class SSLIdentity;
+}
+
+namespace cricket {
+
+struct TransportOptions {
+  TransportOptions() : ice_restart(false), prefer_passive_role(false) {}
+  bool ice_restart;
+  bool prefer_passive_role;
+};
+
+// Creates transport descriptions according to the supplied configuration.
+// When creating answers, performs the appropriate negotiation
+// of the various fields to determine the proper result.
+class TransportDescriptionFactory {
+ public:
+  // Default ctor; use methods below to set configuration.
+  TransportDescriptionFactory();
+  SecurePolicy secure() const { return secure_; }
+  // The identity to use when setting up DTLS.
+  rtc::SSLIdentity* identity() const { return identity_; }
+
+  // Specifies the transport protocol to be use.
+  void set_protocol(TransportProtocol protocol) { protocol_ = protocol; }
+  // Specifies the transport security policy to use.
+  void set_secure(SecurePolicy s) { secure_ = s; }
+  // Specifies the identity to use (only used when secure is not SEC_DISABLED).
+  void set_identity(rtc::SSLIdentity* identity) { identity_ = identity; }
+
+  // Creates a transport description suitable for use in an offer.
+  TransportDescription* CreateOffer(const TransportOptions& options,
+      const TransportDescription* current_description) const;
+  // Create a transport description that is a response to an offer.
+  TransportDescription* CreateAnswer(
+      const TransportDescription* offer,
+      const TransportOptions& options,
+      const TransportDescription* current_description) const;
+
+ private:
+  bool SetSecurityInfo(TransportDescription* description,
+                       ConnectionRole role) const;
+
+  TransportProtocol protocol_;
+  SecurePolicy secure_;
+  rtc::SSLIdentity* identity_;
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_TRANSPORTDESCRIPTIONFACTORY_H_
diff --git a/webrtc/p2p/base/transportdescriptionfactory_unittest.cc b/webrtc/p2p/base/transportdescriptionfactory_unittest.cc
new file mode 100644
index 0000000..22816a2
--- /dev/null
+++ b/webrtc/p2p/base/transportdescriptionfactory_unittest.cc
@@ -0,0 +1,365 @@
+/*
+ *  Copyright 2012 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <string>
+#include <vector>
+
+#include "webrtc/p2p/base/constants.h"
+#include "webrtc/p2p/base/transportdescription.h"
+#include "webrtc/p2p/base/transportdescriptionfactory.h"
+#include "webrtc/base/fakesslidentity.h"
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/ssladapter.h"
+
+using rtc::scoped_ptr;
+using cricket::TransportDescriptionFactory;
+using cricket::TransportDescription;
+using cricket::TransportOptions;
+
+class TransportDescriptionFactoryTest : public testing::Test {
+ public:
+  TransportDescriptionFactoryTest()
+      : id1_(new rtc::FakeSSLIdentity("User1")),
+        id2_(new rtc::FakeSSLIdentity("User2")) {
+  }
+
+  void CheckDesc(const TransportDescription* desc, const std::string& type,
+                 const std::string& opt, const std::string& ice_ufrag,
+                 const std::string& ice_pwd, const std::string& dtls_alg) {
+    ASSERT_TRUE(desc != NULL);
+    EXPECT_EQ(type, desc->transport_type);
+    EXPECT_EQ(!opt.empty(), desc->HasOption(opt));
+    if (ice_ufrag.empty() && ice_pwd.empty()) {
+      EXPECT_EQ(static_cast<size_t>(cricket::ICE_UFRAG_LENGTH),
+                desc->ice_ufrag.size());
+      EXPECT_EQ(static_cast<size_t>(cricket::ICE_PWD_LENGTH),
+                desc->ice_pwd.size());
+    } else {
+      EXPECT_EQ(ice_ufrag, desc->ice_ufrag);
+      EXPECT_EQ(ice_pwd, desc->ice_pwd);
+    }
+    if (dtls_alg.empty()) {
+      EXPECT_TRUE(desc->identity_fingerprint.get() == NULL);
+    } else {
+      ASSERT_TRUE(desc->identity_fingerprint.get() != NULL);
+      EXPECT_EQ(desc->identity_fingerprint->algorithm, dtls_alg);
+      EXPECT_GT(desc->identity_fingerprint->digest.length(), 0U);
+    }
+  }
+
+  // This test ice restart by doing two offer answer exchanges. On the second
+  // exchange ice is restarted. The test verifies that the ufrag and password
+  // in the offer and answer is changed.
+  // If |dtls| is true, the test verifies that the finger print is not changed.
+  void TestIceRestart(bool dtls) {
+    if (dtls) {
+      f1_.set_secure(cricket::SEC_ENABLED);
+      f2_.set_secure(cricket::SEC_ENABLED);
+      f1_.set_identity(id1_.get());
+      f2_.set_identity(id2_.get());
+    } else {
+      f1_.set_secure(cricket::SEC_DISABLED);
+      f2_.set_secure(cricket::SEC_DISABLED);
+    }
+
+    cricket::TransportOptions options;
+    // The initial offer / answer exchange.
+    rtc::scoped_ptr<TransportDescription> offer(f1_.CreateOffer(
+        options, NULL));
+    rtc::scoped_ptr<TransportDescription> answer(
+        f2_.CreateAnswer(offer.get(),
+                         options, NULL));
+
+    // Create an updated offer where we restart ice.
+    options.ice_restart = true;
+    rtc::scoped_ptr<TransportDescription> restart_offer(f1_.CreateOffer(
+        options, offer.get()));
+
+    VerifyUfragAndPasswordChanged(dtls, offer.get(), restart_offer.get());
+
+    // Create a new answer. The transport ufrag and password is changed since
+    // |options.ice_restart == true|
+    rtc::scoped_ptr<TransportDescription> restart_answer(
+        f2_.CreateAnswer(restart_offer.get(), options, answer.get()));
+    ASSERT_TRUE(restart_answer.get() != NULL);
+
+    VerifyUfragAndPasswordChanged(dtls, answer.get(), restart_answer.get());
+  }
+
+  void VerifyUfragAndPasswordChanged(bool dtls,
+                                     const TransportDescription* org_desc,
+                                     const TransportDescription* restart_desc) {
+    EXPECT_NE(org_desc->ice_pwd, restart_desc->ice_pwd);
+    EXPECT_NE(org_desc->ice_ufrag, restart_desc->ice_ufrag);
+    EXPECT_EQ(static_cast<size_t>(cricket::ICE_UFRAG_LENGTH),
+              restart_desc->ice_ufrag.size());
+    EXPECT_EQ(static_cast<size_t>(cricket::ICE_PWD_LENGTH),
+              restart_desc->ice_pwd.size());
+    // If DTLS is enabled, make sure the finger print is unchanged.
+    if (dtls) {
+      EXPECT_FALSE(
+          org_desc->identity_fingerprint->GetRfc4572Fingerprint().empty());
+      EXPECT_EQ(org_desc->identity_fingerprint->GetRfc4572Fingerprint(),
+                restart_desc->identity_fingerprint->GetRfc4572Fingerprint());
+    }
+  }
+
+ protected:
+  TransportDescriptionFactory f1_;
+  TransportDescriptionFactory f2_;
+  scoped_ptr<rtc::SSLIdentity> id1_;
+  scoped_ptr<rtc::SSLIdentity> id2_;
+};
+
+// Test that in the default case, we generate the expected G-ICE offer.
+TEST_F(TransportDescriptionFactoryTest, TestOfferGice) {
+  f1_.set_protocol(cricket::ICEPROTO_GOOGLE);
+  scoped_ptr<TransportDescription> desc(f1_.CreateOffer(
+      TransportOptions(), NULL));
+  CheckDesc(desc.get(), cricket::NS_GINGLE_P2P, "", "", "", "");
+}
+
+// Test generating a hybrid offer.
+TEST_F(TransportDescriptionFactoryTest, TestOfferHybrid) {
+  f1_.set_protocol(cricket::ICEPROTO_HYBRID);
+  scoped_ptr<TransportDescription> desc(f1_.CreateOffer(
+      TransportOptions(), NULL));
+  CheckDesc(desc.get(), cricket::NS_JINGLE_ICE_UDP, "google-ice", "", "", "");
+}
+
+// Test generating an ICE-only offer.
+TEST_F(TransportDescriptionFactoryTest, TestOfferIce) {
+  f1_.set_protocol(cricket::ICEPROTO_RFC5245);
+  scoped_ptr<TransportDescription> desc(f1_.CreateOffer(
+      TransportOptions(), NULL));
+  CheckDesc(desc.get(), cricket::NS_JINGLE_ICE_UDP, "", "", "", "");
+}
+
+// Test generating a hybrid offer with DTLS.
+TEST_F(TransportDescriptionFactoryTest, TestOfferHybridDtls) {
+  f1_.set_protocol(cricket::ICEPROTO_HYBRID);
+  f1_.set_secure(cricket::SEC_ENABLED);
+  f1_.set_identity(id1_.get());
+  std::string digest_alg;
+  ASSERT_TRUE(id1_->certificate().GetSignatureDigestAlgorithm(&digest_alg));
+  scoped_ptr<TransportDescription> desc(f1_.CreateOffer(
+      TransportOptions(), NULL));
+  CheckDesc(desc.get(), cricket::NS_JINGLE_ICE_UDP, "google-ice", "", "",
+            digest_alg);
+  // Ensure it also works with SEC_REQUIRED.
+  f1_.set_secure(cricket::SEC_REQUIRED);
+  desc.reset(f1_.CreateOffer(TransportOptions(), NULL));
+  CheckDesc(desc.get(), cricket::NS_JINGLE_ICE_UDP, "google-ice", "", "",
+            digest_alg);
+}
+
+// Test generating a hybrid offer with DTLS fails with no identity.
+TEST_F(TransportDescriptionFactoryTest, TestOfferHybridDtlsWithNoIdentity) {
+  f1_.set_protocol(cricket::ICEPROTO_HYBRID);
+  f1_.set_secure(cricket::SEC_ENABLED);
+  scoped_ptr<TransportDescription> desc(f1_.CreateOffer(
+      TransportOptions(), NULL));
+  ASSERT_TRUE(desc.get() == NULL);
+}
+
+// Test updating a hybrid offer with DTLS to pick ICE.
+// The ICE credentials should stay the same in the new offer.
+TEST_F(TransportDescriptionFactoryTest, TestOfferHybridDtlsReofferIceDtls) {
+  f1_.set_protocol(cricket::ICEPROTO_HYBRID);
+  f1_.set_secure(cricket::SEC_ENABLED);
+  f1_.set_identity(id1_.get());
+  std::string digest_alg;
+  ASSERT_TRUE(id1_->certificate().GetSignatureDigestAlgorithm(&digest_alg));
+  scoped_ptr<TransportDescription> old_desc(f1_.CreateOffer(
+      TransportOptions(), NULL));
+  ASSERT_TRUE(old_desc.get() != NULL);
+  f1_.set_protocol(cricket::ICEPROTO_RFC5245);
+  scoped_ptr<TransportDescription> desc(
+      f1_.CreateOffer(TransportOptions(), old_desc.get()));
+  CheckDesc(desc.get(), cricket::NS_JINGLE_ICE_UDP, "",
+            old_desc->ice_ufrag, old_desc->ice_pwd, digest_alg);
+}
+
+// Test that we can answer a GICE offer with GICE.
+TEST_F(TransportDescriptionFactoryTest, TestAnswerGiceToGice) {
+  f1_.set_protocol(cricket::ICEPROTO_GOOGLE);
+  f2_.set_protocol(cricket::ICEPROTO_GOOGLE);
+  scoped_ptr<TransportDescription> offer(f1_.CreateOffer(
+      TransportOptions(), NULL));
+  ASSERT_TRUE(offer.get() != NULL);
+  scoped_ptr<TransportDescription> desc(f2_.CreateAnswer(
+      offer.get(), TransportOptions(), NULL));
+  CheckDesc(desc.get(), cricket::NS_GINGLE_P2P, "", "", "", "");
+  // Should get the same result when answering as hybrid.
+  f2_.set_protocol(cricket::ICEPROTO_HYBRID);
+  desc.reset(f2_.CreateAnswer(offer.get(), TransportOptions(),
+                              NULL));
+  CheckDesc(desc.get(), cricket::NS_GINGLE_P2P, "", "", "", "");
+}
+
+// Test that we can answer a hybrid offer with GICE.
+TEST_F(TransportDescriptionFactoryTest, TestAnswerGiceToHybrid) {
+  f1_.set_protocol(cricket::ICEPROTO_HYBRID);
+  f2_.set_protocol(cricket::ICEPROTO_GOOGLE);
+  scoped_ptr<TransportDescription> offer(f1_.CreateOffer(
+      TransportOptions(), NULL));
+  ASSERT_TRUE(offer.get() != NULL);
+  scoped_ptr<TransportDescription> desc(
+      f2_.CreateAnswer(offer.get(), TransportOptions(), NULL));
+  CheckDesc(desc.get(), cricket::NS_GINGLE_P2P, "", "", "", "");
+}
+
+// Test that we can answer a hybrid offer with ICE.
+TEST_F(TransportDescriptionFactoryTest, TestAnswerIceToHybrid) {
+  f1_.set_protocol(cricket::ICEPROTO_HYBRID);
+  f2_.set_protocol(cricket::ICEPROTO_RFC5245);
+  scoped_ptr<TransportDescription> offer(f1_.CreateOffer(
+      TransportOptions(), NULL));
+  ASSERT_TRUE(offer.get() != NULL);
+  scoped_ptr<TransportDescription> desc(
+      f2_.CreateAnswer(offer.get(), TransportOptions(), NULL));
+  CheckDesc(desc.get(), cricket::NS_JINGLE_ICE_UDP, "", "", "", "");
+  // Should get the same result when answering as hybrid.
+  f2_.set_protocol(cricket::ICEPROTO_HYBRID);
+  desc.reset(f2_.CreateAnswer(offer.get(), TransportOptions(),
+                              NULL));
+  CheckDesc(desc.get(), cricket::NS_JINGLE_ICE_UDP, "", "", "", "");
+}
+
+// Test that we can answer an ICE offer with ICE.
+TEST_F(TransportDescriptionFactoryTest, TestAnswerIceToIce) {
+  f1_.set_protocol(cricket::ICEPROTO_RFC5245);
+  f2_.set_protocol(cricket::ICEPROTO_RFC5245);
+  scoped_ptr<TransportDescription> offer(f1_.CreateOffer(
+      TransportOptions(), NULL));
+  ASSERT_TRUE(offer.get() != NULL);
+  scoped_ptr<TransportDescription> desc(f2_.CreateAnswer(
+      offer.get(), TransportOptions(), NULL));
+  CheckDesc(desc.get(), cricket::NS_JINGLE_ICE_UDP, "", "", "", "");
+  // Should get the same result when answering as hybrid.
+  f2_.set_protocol(cricket::ICEPROTO_HYBRID);
+  desc.reset(f2_.CreateAnswer(offer.get(), TransportOptions(),
+                              NULL));
+  CheckDesc(desc.get(), cricket::NS_JINGLE_ICE_UDP, "", "", "", "");
+}
+
+// Test that we can't answer a GICE offer with ICE.
+TEST_F(TransportDescriptionFactoryTest, TestAnswerIceToGice) {
+  f1_.set_protocol(cricket::ICEPROTO_GOOGLE);
+  f2_.set_protocol(cricket::ICEPROTO_RFC5245);
+  scoped_ptr<TransportDescription> offer(
+      f1_.CreateOffer(TransportOptions(), NULL));
+  ASSERT_TRUE(offer.get() != NULL);
+  scoped_ptr<TransportDescription> desc(
+      f2_.CreateAnswer(offer.get(), TransportOptions(), NULL));
+  ASSERT_TRUE(desc.get() == NULL);
+}
+
+// Test that we can't answer an ICE offer with GICE.
+TEST_F(TransportDescriptionFactoryTest, TestAnswerGiceToIce) {
+  f1_.set_protocol(cricket::ICEPROTO_RFC5245);
+  f2_.set_protocol(cricket::ICEPROTO_GOOGLE);
+  scoped_ptr<TransportDescription> offer(
+      f1_.CreateOffer(TransportOptions(), NULL));
+  ASSERT_TRUE(offer.get() != NULL);
+  scoped_ptr<TransportDescription> desc(f2_.CreateAnswer(
+      offer.get(), TransportOptions(), NULL));
+  ASSERT_TRUE(desc.get() == NULL);
+}
+
+// Test that we can update an answer properly; ICE credentials shouldn't change.
+TEST_F(TransportDescriptionFactoryTest, TestAnswerIceToIceReanswer) {
+  f1_.set_protocol(cricket::ICEPROTO_RFC5245);
+  f2_.set_protocol(cricket::ICEPROTO_RFC5245);
+  scoped_ptr<TransportDescription> offer(
+      f1_.CreateOffer(TransportOptions(), NULL));
+  ASSERT_TRUE(offer.get() != NULL);
+  scoped_ptr<TransportDescription> old_desc(
+      f2_.CreateAnswer(offer.get(), TransportOptions(), NULL));
+  ASSERT_TRUE(old_desc.get() != NULL);
+  scoped_ptr<TransportDescription> desc(
+      f2_.CreateAnswer(offer.get(), TransportOptions(),
+                       old_desc.get()));
+  ASSERT_TRUE(desc.get() != NULL);
+  CheckDesc(desc.get(), cricket::NS_JINGLE_ICE_UDP, "",
+            old_desc->ice_ufrag, old_desc->ice_pwd, "");
+}
+
+// Test that we handle answering an offer with DTLS with no DTLS.
+TEST_F(TransportDescriptionFactoryTest, TestAnswerHybridToHybridDtls) {
+  f1_.set_protocol(cricket::ICEPROTO_HYBRID);
+  f1_.set_secure(cricket::SEC_ENABLED);
+  f1_.set_identity(id1_.get());
+  f2_.set_protocol(cricket::ICEPROTO_HYBRID);
+  scoped_ptr<TransportDescription> offer(
+      f1_.CreateOffer(TransportOptions(), NULL));
+  ASSERT_TRUE(offer.get() != NULL);
+  scoped_ptr<TransportDescription> desc(
+      f2_.CreateAnswer(offer.get(), TransportOptions(), NULL));
+  CheckDesc(desc.get(), cricket::NS_JINGLE_ICE_UDP, "", "", "", "");
+}
+
+// Test that we handle answering an offer without DTLS if we have DTLS enabled,
+// but fail if we require DTLS.
+TEST_F(TransportDescriptionFactoryTest, TestAnswerHybridDtlsToHybrid) {
+  f1_.set_protocol(cricket::ICEPROTO_HYBRID);
+  f2_.set_protocol(cricket::ICEPROTO_HYBRID);
+  f2_.set_secure(cricket::SEC_ENABLED);
+  f2_.set_identity(id2_.get());
+  scoped_ptr<TransportDescription> offer(
+      f1_.CreateOffer(TransportOptions(), NULL));
+  ASSERT_TRUE(offer.get() != NULL);
+  scoped_ptr<TransportDescription> desc(
+      f2_.CreateAnswer(offer.get(), TransportOptions(), NULL));
+  CheckDesc(desc.get(), cricket::NS_JINGLE_ICE_UDP, "", "", "", "");
+  f2_.set_secure(cricket::SEC_REQUIRED);
+  desc.reset(f2_.CreateAnswer(offer.get(), TransportOptions(),
+                              NULL));
+  ASSERT_TRUE(desc.get() == NULL);
+}
+
+// Test that we handle answering an DTLS offer with DTLS, both if we have
+// DTLS enabled and required.
+TEST_F(TransportDescriptionFactoryTest, TestAnswerHybridDtlsToHybridDtls) {
+  f1_.set_protocol(cricket::ICEPROTO_HYBRID);
+  f1_.set_secure(cricket::SEC_ENABLED);
+  f1_.set_identity(id1_.get());
+
+  f2_.set_protocol(cricket::ICEPROTO_HYBRID);
+  f2_.set_secure(cricket::SEC_ENABLED);
+  f2_.set_identity(id2_.get());
+  // f2_ produces the answer that is being checked in this test, so the
+  // answer must contain fingerprint lines with id2_'s digest algorithm.
+  std::string digest_alg2;
+  ASSERT_TRUE(id2_->certificate().GetSignatureDigestAlgorithm(&digest_alg2));
+
+  scoped_ptr<TransportDescription> offer(
+      f1_.CreateOffer(TransportOptions(), NULL));
+  ASSERT_TRUE(offer.get() != NULL);
+  scoped_ptr<TransportDescription> desc(
+      f2_.CreateAnswer(offer.get(), TransportOptions(), NULL));
+  CheckDesc(desc.get(), cricket::NS_JINGLE_ICE_UDP, "", "", "", digest_alg2);
+  f2_.set_secure(cricket::SEC_REQUIRED);
+  desc.reset(f2_.CreateAnswer(offer.get(), TransportOptions(),
+                              NULL));
+  CheckDesc(desc.get(), cricket::NS_JINGLE_ICE_UDP, "", "", "", digest_alg2);
+}
+
+// Test that ice ufrag and password is changed in an updated offer and answer
+// if |TransportDescriptionOptions::ice_restart| is true.
+TEST_F(TransportDescriptionFactoryTest, TestIceRestart) {
+  TestIceRestart(false);
+}
+
+// Test that ice ufrag and password is changed in an updated offer and answer
+// if |TransportDescriptionOptions::ice_restart| is true and DTLS is enabled.
+TEST_F(TransportDescriptionFactoryTest, TestIceRestartWithDtls) {
+  TestIceRestart(true);
+}
diff --git a/webrtc/p2p/base/transportinfo.h b/webrtc/p2p/base/transportinfo.h
new file mode 100644
index 0000000..3fbf204
--- /dev/null
+++ b/webrtc/p2p/base/transportinfo.h
@@ -0,0 +1,43 @@
+/*
+ *  Copyright 2012 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_TRANSPORTINFO_H_
+#define WEBRTC_P2P_BASE_TRANSPORTINFO_H_
+
+#include <string>
+#include <vector>
+
+#include "webrtc/p2p/base/candidate.h"
+#include "webrtc/p2p/base/constants.h"
+#include "webrtc/p2p/base/transportdescription.h"
+#include "webrtc/base/helpers.h"
+
+namespace cricket {
+
+// A TransportInfo is NOT a transport-info message.  It is comparable
+// to a "ContentInfo". A transport-infos message is basically just a
+// collection of TransportInfos.
+struct TransportInfo {
+  TransportInfo() {}
+
+  TransportInfo(const std::string& content_name,
+                const TransportDescription& description)
+      : content_name(content_name),
+        description(description) {}
+
+  std::string content_name;
+  TransportDescription description;
+};
+
+typedef std::vector<TransportInfo> TransportInfos;
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_TRANSPORTINFO_H_
diff --git a/webrtc/p2p/base/turnport.cc b/webrtc/p2p/base/turnport.cc
new file mode 100644
index 0000000..e7626fe
--- /dev/null
+++ b/webrtc/p2p/base/turnport.cc
@@ -0,0 +1,1196 @@
+/*
+ *  Copyright 2012 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/turnport.h"
+
+#include <functional>
+
+#include "webrtc/p2p/base/common.h"
+#include "webrtc/p2p/base/stun.h"
+#include "webrtc/base/asyncpacketsocket.h"
+#include "webrtc/base/byteorder.h"
+#include "webrtc/base/common.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/nethelpers.h"
+#include "webrtc/base/socketaddress.h"
+#include "webrtc/base/stringencode.h"
+
+namespace cricket {
+
+// TODO(juberti): Move to stun.h when relay messages have been renamed.
+static const int TURN_ALLOCATE_REQUEST = STUN_ALLOCATE_REQUEST;
+
+// TODO(juberti): Extract to turnmessage.h
+static const int TURN_DEFAULT_PORT = 3478;
+static const int TURN_CHANNEL_NUMBER_START = 0x4000;
+static const int TURN_PERMISSION_TIMEOUT = 5 * 60 * 1000;  // 5 minutes
+
+static const size_t TURN_CHANNEL_HEADER_SIZE = 4U;
+
+// Retry at most twice (i.e. three different ALLOCATE requests) on
+// STUN_ERROR_ALLOCATION_MISMATCH error per rfc5766.
+static const size_t MAX_ALLOCATE_MISMATCH_RETRIES = 2;
+
+inline bool IsTurnChannelData(uint16 msg_type) {
+  return ((msg_type & 0xC000) == 0x4000);  // MSB are 0b01
+}
+
+static int GetRelayPreference(cricket::ProtocolType proto, bool secure) {
+  int relay_preference = ICE_TYPE_PREFERENCE_RELAY;
+  if (proto == cricket::PROTO_TCP) {
+    relay_preference -= 1;
+    if (secure)
+      relay_preference -= 1;
+  }
+
+  ASSERT(relay_preference >= 0);
+  return relay_preference;
+}
+
+class TurnAllocateRequest : public StunRequest {
+ public:
+  explicit TurnAllocateRequest(TurnPort* port);
+  virtual void Prepare(StunMessage* request);
+  virtual void OnResponse(StunMessage* response);
+  virtual void OnErrorResponse(StunMessage* response);
+  virtual void OnTimeout();
+
+ private:
+  // Handles authentication challenge from the server.
+  void OnAuthChallenge(StunMessage* response, int code);
+  void OnTryAlternate(StunMessage* response, int code);
+  void OnUnknownAttribute(StunMessage* response);
+
+  TurnPort* port_;
+};
+
+class TurnRefreshRequest : public StunRequest {
+ public:
+  explicit TurnRefreshRequest(TurnPort* port);
+  virtual void Prepare(StunMessage* request);
+  virtual void OnResponse(StunMessage* response);
+  virtual void OnErrorResponse(StunMessage* response);
+  virtual void OnTimeout();
+
+ private:
+  TurnPort* port_;
+};
+
+class TurnCreatePermissionRequest : public StunRequest,
+                                    public sigslot::has_slots<> {
+ public:
+  TurnCreatePermissionRequest(TurnPort* port, TurnEntry* entry,
+                              const rtc::SocketAddress& ext_addr);
+  virtual void Prepare(StunMessage* request);
+  virtual void OnResponse(StunMessage* response);
+  virtual void OnErrorResponse(StunMessage* response);
+  virtual void OnTimeout();
+
+ private:
+  void OnEntryDestroyed(TurnEntry* entry);
+
+  TurnPort* port_;
+  TurnEntry* entry_;
+  rtc::SocketAddress ext_addr_;
+};
+
+class TurnChannelBindRequest : public StunRequest,
+                               public sigslot::has_slots<> {
+ public:
+  TurnChannelBindRequest(TurnPort* port, TurnEntry* entry, int channel_id,
+                         const rtc::SocketAddress& ext_addr);
+  virtual void Prepare(StunMessage* request);
+  virtual void OnResponse(StunMessage* response);
+  virtual void OnErrorResponse(StunMessage* response);
+  virtual void OnTimeout();
+
+ private:
+  void OnEntryDestroyed(TurnEntry* entry);
+
+  TurnPort* port_;
+  TurnEntry* entry_;
+  int channel_id_;
+  rtc::SocketAddress ext_addr_;
+};
+
+// Manages a "connection" to a remote destination. We will attempt to bring up
+// a channel for this remote destination to reduce the overhead of sending data.
+class TurnEntry : public sigslot::has_slots<> {
+ public:
+  enum BindState { STATE_UNBOUND, STATE_BINDING, STATE_BOUND };
+  TurnEntry(TurnPort* port, int channel_id,
+            const rtc::SocketAddress& ext_addr);
+
+  TurnPort* port() { return port_; }
+
+  int channel_id() const { return channel_id_; }
+  const rtc::SocketAddress& address() const { return ext_addr_; }
+  BindState state() const { return state_; }
+
+  // Helper methods to send permission and channel bind requests.
+  void SendCreatePermissionRequest();
+  void SendChannelBindRequest(int delay);
+  // Sends a packet to the given destination address.
+  // This will wrap the packet in STUN if necessary.
+  int Send(const void* data, size_t size, bool payload,
+           const rtc::PacketOptions& options);
+
+  void OnCreatePermissionSuccess();
+  void OnCreatePermissionError(StunMessage* response, int code);
+  void OnChannelBindSuccess();
+  void OnChannelBindError(StunMessage* response, int code);
+  // Signal sent when TurnEntry is destroyed.
+  sigslot::signal1<TurnEntry*> SignalDestroyed;
+
+ private:
+  TurnPort* port_;
+  int channel_id_;
+  rtc::SocketAddress ext_addr_;
+  BindState state_;
+};
+
+TurnPort::TurnPort(rtc::Thread* thread,
+                   rtc::PacketSocketFactory* factory,
+                   rtc::Network* network,
+                   rtc::AsyncPacketSocket* socket,
+                   const std::string& username,
+                   const std::string& password,
+                   const ProtocolAddress& server_address,
+                   const RelayCredentials& credentials,
+                   int server_priority)
+    : Port(thread, factory, network, socket->GetLocalAddress().ipaddr(),
+           username, password),
+      server_address_(server_address),
+      credentials_(credentials),
+      socket_(socket),
+      resolver_(NULL),
+      error_(0),
+      request_manager_(thread),
+      next_channel_number_(TURN_CHANNEL_NUMBER_START),
+      connected_(false),
+      server_priority_(server_priority),
+      allocate_mismatch_retries_(0) {
+  request_manager_.SignalSendPacket.connect(this, &TurnPort::OnSendStunPacket);
+}
+
+TurnPort::TurnPort(rtc::Thread* thread,
+                   rtc::PacketSocketFactory* factory,
+                   rtc::Network* network,
+                   const rtc::IPAddress& ip,
+                   int min_port, int max_port,
+                   const std::string& username,
+                   const std::string& password,
+                   const ProtocolAddress& server_address,
+                   const RelayCredentials& credentials,
+                   int server_priority)
+    : Port(thread, RELAY_PORT_TYPE, factory, network, ip, min_port, max_port,
+           username, password),
+      server_address_(server_address),
+      credentials_(credentials),
+      socket_(NULL),
+      resolver_(NULL),
+      error_(0),
+      request_manager_(thread),
+      next_channel_number_(TURN_CHANNEL_NUMBER_START),
+      connected_(false),
+      server_priority_(server_priority),
+      allocate_mismatch_retries_(0) {
+  request_manager_.SignalSendPacket.connect(this, &TurnPort::OnSendStunPacket);
+}
+
+TurnPort::~TurnPort() {
+  // TODO(juberti): Should this even be necessary?
+  while (!entries_.empty()) {
+    DestroyEntry(entries_.front()->address());
+  }
+  if (resolver_) {
+    resolver_->Destroy(false);
+  }
+  if (!SharedSocket()) {
+    delete socket_;
+  }
+}
+
+void TurnPort::PrepareAddress() {
+  if (credentials_.username.empty() ||
+      credentials_.password.empty()) {
+    LOG(LS_ERROR) << "Allocation can't be started without setting the"
+                  << " TURN server credentials for the user.";
+    OnAllocateError();
+    return;
+  }
+
+  if (!server_address_.address.port()) {
+    // We will set default TURN port, if no port is set in the address.
+    server_address_.address.SetPort(TURN_DEFAULT_PORT);
+  }
+
+  if (server_address_.address.IsUnresolved()) {
+    ResolveTurnAddress(server_address_.address);
+  } else {
+    // If protocol family of server address doesn't match with local, return.
+    if (!IsCompatibleAddress(server_address_.address)) {
+      LOG(LS_ERROR) << "Server IP address family does not match with "
+                    << "local host address family type";
+      OnAllocateError();
+      return;
+    }
+
+    // Insert the current address to prevent redirection pingpong.
+    attempted_server_addresses_.insert(server_address_.address);
+
+    LOG_J(LS_INFO, this) << "Trying to connect to TURN server via "
+                         << ProtoToString(server_address_.proto) << " @ "
+                         << server_address_.address.ToSensitiveString();
+    if (!CreateTurnClientSocket()) {
+      OnAllocateError();
+    } else if (server_address_.proto == PROTO_UDP) {
+      // If its UDP, send AllocateRequest now.
+      // For TCP and TLS AllcateRequest will be sent by OnSocketConnect.
+      SendRequest(new TurnAllocateRequest(this), 0);
+    }
+  }
+}
+
+bool TurnPort::CreateTurnClientSocket() {
+  ASSERT(!socket_ || SharedSocket());
+
+  if (server_address_.proto == PROTO_UDP && !SharedSocket()) {
+    socket_ = socket_factory()->CreateUdpSocket(
+        rtc::SocketAddress(ip(), 0), min_port(), max_port());
+  } else if (server_address_.proto == PROTO_TCP) {
+    ASSERT(!SharedSocket());
+    int opts = rtc::PacketSocketFactory::OPT_STUN;
+    // If secure bit is enabled in server address, use TLS over TCP.
+    if (server_address_.secure) {
+      opts |= rtc::PacketSocketFactory::OPT_TLS;
+    }
+    socket_ = socket_factory()->CreateClientTcpSocket(
+        rtc::SocketAddress(ip(), 0), server_address_.address,
+        proxy(), user_agent(), opts);
+  }
+
+  if (!socket_) {
+    error_ = SOCKET_ERROR;
+    return false;
+  }
+
+  // Apply options if any.
+  for (SocketOptionsMap::iterator iter = socket_options_.begin();
+       iter != socket_options_.end(); ++iter) {
+    socket_->SetOption(iter->first, iter->second);
+  }
+
+  if (!SharedSocket()) {
+    // If socket is shared, AllocationSequence will receive the packet.
+    socket_->SignalReadPacket.connect(this, &TurnPort::OnReadPacket);
+  }
+
+  socket_->SignalReadyToSend.connect(this, &TurnPort::OnReadyToSend);
+
+  if (server_address_.proto == PROTO_TCP) {
+    socket_->SignalConnect.connect(this, &TurnPort::OnSocketConnect);
+    socket_->SignalClose.connect(this, &TurnPort::OnSocketClose);
+  }
+  return true;
+}
+
+void TurnPort::OnSocketConnect(rtc::AsyncPacketSocket* socket) {
+  ASSERT(server_address_.proto == PROTO_TCP);
+  // Do not use this port if the socket bound to a different address than
+  // the one we asked for. This is seen in Chrome, where TCP sockets cannot be
+  // given a binding address, and the platform is expected to pick the
+  // correct local address.
+  if (socket->GetLocalAddress().ipaddr() != ip()) {
+    LOG(LS_WARNING) << "Socket is bound to a different address then the "
+                    << "local port. Discarding TURN port.";
+    OnAllocateError();
+    return;
+  }
+
+  if (server_address_.address.IsUnresolved()) {
+    server_address_.address = socket_->GetRemoteAddress();
+  }
+
+  LOG(LS_INFO) << "TurnPort connected to " << socket->GetRemoteAddress()
+               << " using tcp.";
+  SendRequest(new TurnAllocateRequest(this), 0);
+}
+
+void TurnPort::OnSocketClose(rtc::AsyncPacketSocket* socket, int error) {
+  LOG_J(LS_WARNING, this) << "Connection with server failed, error=" << error;
+  if (!connected_) {
+    OnAllocateError();
+  }
+}
+
+void TurnPort::OnAllocateMismatch() {
+  if (allocate_mismatch_retries_ >= MAX_ALLOCATE_MISMATCH_RETRIES) {
+    LOG_J(LS_WARNING, this) << "Giving up on the port after "
+                            << allocate_mismatch_retries_
+                            << " retries for STUN_ERROR_ALLOCATION_MISMATCH";
+    OnAllocateError();
+    return;
+  }
+
+  LOG_J(LS_INFO, this) << "Allocating a new socket after "
+                       << "STUN_ERROR_ALLOCATION_MISMATCH, retry = "
+                       << allocate_mismatch_retries_ + 1;
+  if (SharedSocket()) {
+    ResetSharedSocket();
+  } else {
+    delete socket_;
+  }
+  socket_ = NULL;
+
+  PrepareAddress();
+  ++allocate_mismatch_retries_;
+}
+
+Connection* TurnPort::CreateConnection(const Candidate& address,
+                                       CandidateOrigin origin) {
+  // TURN-UDP can only connect to UDP candidates.
+  if (address.protocol() != UDP_PROTOCOL_NAME) {
+    return NULL;
+  }
+
+  if (!IsCompatibleAddress(address.address())) {
+    return NULL;
+  }
+
+  // Create an entry, if needed, so we can get our permissions set up correctly.
+  CreateEntry(address.address());
+
+  // A TURN port will have two candiates, STUN and TURN. STUN may not
+  // present in all cases. If present stun candidate will be added first
+  // and TURN candidate later.
+  for (size_t index = 0; index < Candidates().size(); ++index) {
+    if (Candidates()[index].type() == RELAY_PORT_TYPE) {
+      ProxyConnection* conn = new ProxyConnection(this, index, address);
+      conn->SignalDestroyed.connect(this, &TurnPort::OnConnectionDestroyed);
+      AddConnection(conn);
+      return conn;
+    }
+  }
+  return NULL;
+}
+
+int TurnPort::SetOption(rtc::Socket::Option opt, int value) {
+  if (!socket_) {
+    // If socket is not created yet, these options will be applied during socket
+    // creation.
+    socket_options_[opt] = value;
+    return 0;
+  }
+  return socket_->SetOption(opt, value);
+}
+
+int TurnPort::GetOption(rtc::Socket::Option opt, int* value) {
+  if (!socket_) {
+    SocketOptionsMap::const_iterator it = socket_options_.find(opt);
+    if (it == socket_options_.end()) {
+      return -1;
+    }
+    *value = it->second;
+    return 0;
+  }
+
+  return socket_->GetOption(opt, value);
+}
+
+int TurnPort::GetError() {
+  return error_;
+}
+
+int TurnPort::SendTo(const void* data, size_t size,
+                     const rtc::SocketAddress& addr,
+                     const rtc::PacketOptions& options,
+                     bool payload) {
+  // Try to find an entry for this specific address; we should have one.
+  TurnEntry* entry = FindEntry(addr);
+  ASSERT(entry != NULL);
+  if (!entry) {
+    return 0;
+  }
+
+  if (!connected()) {
+    error_ = EWOULDBLOCK;
+    return SOCKET_ERROR;
+  }
+
+  // Send the actual contents to the server using the usual mechanism.
+  int sent = entry->Send(data, size, payload, options);
+  if (sent <= 0) {
+    return SOCKET_ERROR;
+  }
+
+  // The caller of the function is expecting the number of user data bytes,
+  // rather than the size of the packet.
+  return static_cast<int>(size);
+}
+
+void TurnPort::OnReadPacket(
+    rtc::AsyncPacketSocket* socket, const char* data, size_t size,
+    const rtc::SocketAddress& remote_addr,
+    const rtc::PacketTime& packet_time) {
+  ASSERT(socket == socket_);
+  ASSERT(remote_addr == server_address_.address);
+
+  // The message must be at least the size of a channel header.
+  if (size < TURN_CHANNEL_HEADER_SIZE) {
+    LOG_J(LS_WARNING, this) << "Received TURN message that was too short";
+    return;
+  }
+
+  // Check the message type, to see if is a Channel Data message.
+  // The message will either be channel data, a TURN data indication, or
+  // a response to a previous request.
+  uint16 msg_type = rtc::GetBE16(data);
+  if (IsTurnChannelData(msg_type)) {
+    HandleChannelData(msg_type, data, size, packet_time);
+  } else if (msg_type == TURN_DATA_INDICATION) {
+    HandleDataIndication(data, size, packet_time);
+  } else {
+    // This must be a response for one of our requests.
+    // Check success responses, but not errors, for MESSAGE-INTEGRITY.
+    if (IsStunSuccessResponseType(msg_type) &&
+        !StunMessage::ValidateMessageIntegrity(data, size, hash())) {
+      LOG_J(LS_WARNING, this) << "Received TURN message with invalid "
+                              << "message integrity, msg_type=" << msg_type;
+      return;
+    }
+    request_manager_.CheckResponse(data, size);
+  }
+}
+
+void TurnPort::OnReadyToSend(rtc::AsyncPacketSocket* socket) {
+  if (connected_) {
+    Port::OnReadyToSend();
+  }
+}
+
+
+// Update current server address port with the alternate server address port.
+bool TurnPort::SetAlternateServer(const rtc::SocketAddress& address) {
+  // Check if we have seen this address before and reject if we did.
+  AttemptedServerSet::iterator iter = attempted_server_addresses_.find(address);
+  if (iter != attempted_server_addresses_.end()) {
+    LOG_J(LS_WARNING, this) << "Redirection to ["
+                            << address.ToSensitiveString()
+                            << "] ignored, allocation failed.";
+    return false;
+  }
+
+  // If protocol family of server address doesn't match with local, return.
+  if (!IsCompatibleAddress(address)) {
+    LOG(LS_WARNING) << "Server IP address family does not match with "
+                    << "local host address family type";
+    return false;
+  }
+
+  LOG_J(LS_INFO, this) << "Redirecting from TURN server ["
+                       << server_address_.address.ToSensitiveString()
+                       << "] to TURN server ["
+                       << address.ToSensitiveString()
+                       << "]";
+  server_address_ = ProtocolAddress(address, server_address_.proto,
+                                    server_address_.secure);
+
+  // Insert the current address to prevent redirection pingpong.
+  attempted_server_addresses_.insert(server_address_.address);
+  return true;
+}
+
+void TurnPort::ResolveTurnAddress(const rtc::SocketAddress& address) {
+  if (resolver_)
+    return;
+
+  resolver_ = socket_factory()->CreateAsyncResolver();
+  resolver_->SignalDone.connect(this, &TurnPort::OnResolveResult);
+  resolver_->Start(address);
+}
+
+void TurnPort::OnResolveResult(rtc::AsyncResolverInterface* resolver) {
+  ASSERT(resolver == resolver_);
+  // If DNS resolve is failed when trying to connect to the server using TCP,
+  // one of the reason could be due to DNS queries blocked by firewall.
+  // In such cases we will try to connect to the server with hostname, assuming
+  // socket layer will resolve the hostname through a HTTP proxy (if any).
+  if (resolver_->GetError() != 0 && server_address_.proto == PROTO_TCP) {
+    if (!CreateTurnClientSocket()) {
+      OnAllocateError();
+    }
+    return;
+  }
+
+  // Copy the original server address in |resolved_address|. For TLS based
+  // sockets we need hostname along with resolved address.
+  rtc::SocketAddress resolved_address = server_address_.address;
+  if (resolver_->GetError() != 0 ||
+      !resolver_->GetResolvedAddress(ip().family(), &resolved_address)) {
+    LOG_J(LS_WARNING, this) << "TURN host lookup received error "
+                            << resolver_->GetError();
+    error_ = resolver_->GetError();
+    OnAllocateError();
+    return;
+  }
+  // Signal needs both resolved and unresolved address. After signal is sent
+  // we can copy resolved address back into |server_address_|.
+  SignalResolvedServerAddress(this, server_address_.address,
+                              resolved_address);
+  server_address_.address = resolved_address;
+  PrepareAddress();
+}
+
+void TurnPort::OnSendStunPacket(const void* data, size_t size,
+                                StunRequest* request) {
+  rtc::PacketOptions options(DefaultDscpValue());
+  if (Send(data, size, options) < 0) {
+    LOG_J(LS_ERROR, this) << "Failed to send TURN message, err="
+                          << socket_->GetError();
+  }
+}
+
+void TurnPort::OnStunAddress(const rtc::SocketAddress& address) {
+  // STUN Port will discover STUN candidate, as it's supplied with first TURN
+  // server address.
+  // Why not using this address? - P2PTransportChannel will start creating
+  // connections after first candidate, which means it could start creating the
+  // connections before TURN candidate added. For that to handle, we need to
+  // supply STUN candidate from this port to UDPPort, and TurnPort should have
+  // handle to UDPPort to pass back the address.
+}
+
+void TurnPort::OnAllocateSuccess(const rtc::SocketAddress& address,
+                                 const rtc::SocketAddress& stun_address) {
+  connected_ = true;
+
+  rtc::SocketAddress related_address = stun_address;
+    if (!(candidate_filter() & CF_REFLEXIVE)) {
+    // If candidate filter only allows relay type of address, empty raddr to
+    // avoid local address leakage.
+    related_address = rtc::EmptySocketAddressWithFamily(stun_address.family());
+  }
+
+  // For relayed candidate, Base is the candidate itself.
+  AddAddress(address,          // Candidate address.
+             address,          // Base address.
+             related_address,  // Related address.
+             UDP_PROTOCOL_NAME,
+             "",  // TCP canddiate type, empty for turn candidates.
+             RELAY_PORT_TYPE,
+             GetRelayPreference(server_address_.proto, server_address_.secure),
+             server_priority_,
+             true);
+}
+
+void TurnPort::OnAllocateError() {
+  // We will send SignalPortError asynchronously as this can be sent during
+  // port initialization. This way it will not be blocking other port
+  // creation.
+  thread()->Post(this, MSG_ERROR);
+}
+
+void TurnPort::OnMessage(rtc::Message* message) {
+  if (message->message_id == MSG_ERROR) {
+    SignalPortError(this);
+    return;
+  } else if (message->message_id == MSG_ALLOCATE_MISMATCH) {
+    OnAllocateMismatch();
+    return;
+  }
+
+  Port::OnMessage(message);
+}
+
+void TurnPort::OnAllocateRequestTimeout() {
+  OnAllocateError();
+}
+
+void TurnPort::HandleDataIndication(const char* data, size_t size,
+                                    const rtc::PacketTime& packet_time) {
+  // Read in the message, and process according to RFC5766, Section 10.4.
+  rtc::ByteBuffer buf(data, size);
+  TurnMessage msg;
+  if (!msg.Read(&buf)) {
+    LOG_J(LS_WARNING, this) << "Received invalid TURN data indication";
+    return;
+  }
+
+  // Check mandatory attributes.
+  const StunAddressAttribute* addr_attr =
+      msg.GetAddress(STUN_ATTR_XOR_PEER_ADDRESS);
+  if (!addr_attr) {
+    LOG_J(LS_WARNING, this) << "Missing STUN_ATTR_XOR_PEER_ADDRESS attribute "
+                            << "in data indication.";
+    return;
+  }
+
+  const StunByteStringAttribute* data_attr =
+      msg.GetByteString(STUN_ATTR_DATA);
+  if (!data_attr) {
+    LOG_J(LS_WARNING, this) << "Missing STUN_ATTR_DATA attribute in "
+                            << "data indication.";
+    return;
+  }
+
+  // Verify that the data came from somewhere we think we have a permission for.
+  rtc::SocketAddress ext_addr(addr_attr->GetAddress());
+  if (!HasPermission(ext_addr.ipaddr())) {
+    LOG_J(LS_WARNING, this) << "Received TURN data indication with invalid "
+                            << "peer address, addr="
+                            << ext_addr.ToSensitiveString();
+    return;
+  }
+
+  DispatchPacket(data_attr->bytes(), data_attr->length(), ext_addr,
+                 PROTO_UDP, packet_time);
+}
+
+void TurnPort::HandleChannelData(int channel_id, const char* data,
+                                 size_t size,
+                                 const rtc::PacketTime& packet_time) {
+  // Read the message, and process according to RFC5766, Section 11.6.
+  //    0                   1                   2                   3
+  //    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+  //   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+  //   |         Channel Number        |            Length             |
+  //   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+  //   |                                                               |
+  //   /                       Application Data                        /
+  //   /                                                               /
+  //   |                                                               |
+  //   |                               +-------------------------------+
+  //   |                               |
+  //   +-------------------------------+
+
+  // Extract header fields from the message.
+  uint16 len = rtc::GetBE16(data + 2);
+  if (len > size - TURN_CHANNEL_HEADER_SIZE) {
+    LOG_J(LS_WARNING, this) << "Received TURN channel data message with "
+                            << "incorrect length, len=" << len;
+    return;
+  }
+  // Allowing messages larger than |len|, as ChannelData can be padded.
+
+  TurnEntry* entry = FindEntry(channel_id);
+  if (!entry) {
+    LOG_J(LS_WARNING, this) << "Received TURN channel data message for invalid "
+                            << "channel, channel_id=" << channel_id;
+    return;
+  }
+
+  DispatchPacket(data + TURN_CHANNEL_HEADER_SIZE, len, entry->address(),
+                 PROTO_UDP, packet_time);
+}
+
+void TurnPort::DispatchPacket(const char* data, size_t size,
+    const rtc::SocketAddress& remote_addr,
+    ProtocolType proto, const rtc::PacketTime& packet_time) {
+  if (Connection* conn = GetConnection(remote_addr)) {
+    conn->OnReadPacket(data, size, packet_time);
+  } else {
+    Port::OnReadPacket(data, size, remote_addr, proto);
+  }
+}
+
+bool TurnPort::ScheduleRefresh(int lifetime) {
+  // Lifetime is in seconds; we schedule a refresh for one minute less.
+  if (lifetime < 2 * 60) {
+    LOG_J(LS_WARNING, this) << "Received response with lifetime that was "
+                            << "too short, lifetime=" << lifetime;
+    return false;
+  }
+
+  SendRequest(new TurnRefreshRequest(this), (lifetime - 60) * 1000);
+  return true;
+}
+
+void TurnPort::SendRequest(StunRequest* req, int delay) {
+  request_manager_.SendDelayed(req, delay);
+}
+
+void TurnPort::AddRequestAuthInfo(StunMessage* msg) {
+  // If we've gotten the necessary data from the server, add it to our request.
+  VERIFY(!hash_.empty());
+  VERIFY(msg->AddAttribute(new StunByteStringAttribute(
+      STUN_ATTR_USERNAME, credentials_.username)));
+  VERIFY(msg->AddAttribute(new StunByteStringAttribute(
+      STUN_ATTR_REALM, realm_)));
+  VERIFY(msg->AddAttribute(new StunByteStringAttribute(
+      STUN_ATTR_NONCE, nonce_)));
+  VERIFY(msg->AddMessageIntegrity(hash()));
+}
+
+int TurnPort::Send(const void* data, size_t len,
+                   const rtc::PacketOptions& options) {
+  return socket_->SendTo(data, len, server_address_.address, options);
+}
+
+void TurnPort::UpdateHash() {
+  VERIFY(ComputeStunCredentialHash(credentials_.username, realm_,
+                                   credentials_.password, &hash_));
+}
+
+bool TurnPort::UpdateNonce(StunMessage* response) {
+  // When stale nonce error received, we should update
+  // hash and store realm and nonce.
+  // Check the mandatory attributes.
+  const StunByteStringAttribute* realm_attr =
+      response->GetByteString(STUN_ATTR_REALM);
+  if (!realm_attr) {
+    LOG(LS_ERROR) << "Missing STUN_ATTR_REALM attribute in "
+                  << "stale nonce error response.";
+    return false;
+  }
+  set_realm(realm_attr->GetString());
+
+  const StunByteStringAttribute* nonce_attr =
+      response->GetByteString(STUN_ATTR_NONCE);
+  if (!nonce_attr) {
+    LOG(LS_ERROR) << "Missing STUN_ATTR_NONCE attribute in "
+                  << "stale nonce error response.";
+    return false;
+  }
+  set_nonce(nonce_attr->GetString());
+  return true;
+}
+
+static bool MatchesIP(TurnEntry* e, rtc::IPAddress ipaddr) {
+  return e->address().ipaddr() == ipaddr;
+}
+bool TurnPort::HasPermission(const rtc::IPAddress& ipaddr) const {
+  return (std::find_if(entries_.begin(), entries_.end(),
+      std::bind2nd(std::ptr_fun(MatchesIP), ipaddr)) != entries_.end());
+}
+
+static bool MatchesAddress(TurnEntry* e, rtc::SocketAddress addr) {
+  return e->address() == addr;
+}
+TurnEntry* TurnPort::FindEntry(const rtc::SocketAddress& addr) const {
+  EntryList::const_iterator it = std::find_if(entries_.begin(), entries_.end(),
+      std::bind2nd(std::ptr_fun(MatchesAddress), addr));
+  return (it != entries_.end()) ? *it : NULL;
+}
+
+static bool MatchesChannelId(TurnEntry* e, int id) {
+  return e->channel_id() == id;
+}
+TurnEntry* TurnPort::FindEntry(int channel_id) const {
+  EntryList::const_iterator it = std::find_if(entries_.begin(), entries_.end(),
+      std::bind2nd(std::ptr_fun(MatchesChannelId), channel_id));
+  return (it != entries_.end()) ? *it : NULL;
+}
+
+TurnEntry* TurnPort::CreateEntry(const rtc::SocketAddress& addr) {
+  ASSERT(FindEntry(addr) == NULL);
+  TurnEntry* entry = new TurnEntry(this, next_channel_number_++, addr);
+  entries_.push_back(entry);
+  return entry;
+}
+
+void TurnPort::DestroyEntry(const rtc::SocketAddress& addr) {
+  TurnEntry* entry = FindEntry(addr);
+  ASSERT(entry != NULL);
+  entry->SignalDestroyed(entry);
+  entries_.remove(entry);
+  delete entry;
+}
+
+void TurnPort::OnConnectionDestroyed(Connection* conn) {
+  // Destroying TurnEntry for the connection, which is already destroyed.
+  DestroyEntry(conn->remote_candidate().address());
+}
+
+TurnAllocateRequest::TurnAllocateRequest(TurnPort* port)
+    : StunRequest(new TurnMessage()),
+      port_(port) {
+}
+
+void TurnAllocateRequest::Prepare(StunMessage* request) {
+  // Create the request as indicated in RFC 5766, Section 6.1.
+  request->SetType(TURN_ALLOCATE_REQUEST);
+  StunUInt32Attribute* transport_attr = StunAttribute::CreateUInt32(
+      STUN_ATTR_REQUESTED_TRANSPORT);
+  transport_attr->SetValue(IPPROTO_UDP << 24);
+  VERIFY(request->AddAttribute(transport_attr));
+  if (!port_->hash().empty()) {
+    port_->AddRequestAuthInfo(request);
+  }
+}
+
+void TurnAllocateRequest::OnResponse(StunMessage* response) {
+  // Check mandatory attributes as indicated in RFC5766, Section 6.3.
+  const StunAddressAttribute* mapped_attr =
+      response->GetAddress(STUN_ATTR_XOR_MAPPED_ADDRESS);
+  if (!mapped_attr) {
+    LOG_J(LS_WARNING, port_) << "Missing STUN_ATTR_XOR_MAPPED_ADDRESS "
+                             << "attribute in allocate success response";
+    return;
+  }
+  // Using XOR-Mapped-Address for stun.
+  port_->OnStunAddress(mapped_attr->GetAddress());
+
+  const StunAddressAttribute* relayed_attr =
+      response->GetAddress(STUN_ATTR_XOR_RELAYED_ADDRESS);
+  if (!relayed_attr) {
+    LOG_J(LS_WARNING, port_) << "Missing STUN_ATTR_XOR_RELAYED_ADDRESS "
+                             << "attribute in allocate success response";
+    return;
+  }
+
+  const StunUInt32Attribute* lifetime_attr =
+      response->GetUInt32(STUN_ATTR_TURN_LIFETIME);
+  if (!lifetime_attr) {
+    LOG_J(LS_WARNING, port_) << "Missing STUN_ATTR_TURN_LIFETIME attribute in "
+                             << "allocate success response";
+    return;
+  }
+  // Notify the port the allocate succeeded, and schedule a refresh request.
+  port_->OnAllocateSuccess(relayed_attr->GetAddress(),
+                           mapped_attr->GetAddress());
+  port_->ScheduleRefresh(lifetime_attr->value());
+}
+
+void TurnAllocateRequest::OnErrorResponse(StunMessage* response) {
+  // Process error response according to RFC5766, Section 6.4.
+  const StunErrorCodeAttribute* error_code = response->GetErrorCode();
+  switch (error_code->code()) {
+    case STUN_ERROR_UNAUTHORIZED:       // Unauthrorized.
+      OnAuthChallenge(response, error_code->code());
+      break;
+    case STUN_ERROR_TRY_ALTERNATE:
+      OnTryAlternate(response, error_code->code());
+      break;
+    case STUN_ERROR_ALLOCATION_MISMATCH:
+      // We must handle this error async because trying to delete the socket in
+      // OnErrorResponse will cause a deadlock on the socket.
+      port_->thread()->Post(port_, TurnPort::MSG_ALLOCATE_MISMATCH);
+      break;
+    default:
+      LOG_J(LS_WARNING, port_) << "Allocate response error, code="
+                               << error_code->code();
+      port_->OnAllocateError();
+  }
+}
+
+void TurnAllocateRequest::OnTimeout() {
+  LOG_J(LS_WARNING, port_) << "Allocate request timeout";
+  port_->OnAllocateRequestTimeout();
+}
+
+void TurnAllocateRequest::OnAuthChallenge(StunMessage* response, int code) {
+  // If we failed to authenticate even after we sent our credentials, fail hard.
+  if (code == STUN_ERROR_UNAUTHORIZED && !port_->hash().empty()) {
+    LOG_J(LS_WARNING, port_) << "Failed to authenticate with the server "
+                             << "after challenge.";
+    port_->OnAllocateError();
+    return;
+  }
+
+  // Check the mandatory attributes.
+  const StunByteStringAttribute* realm_attr =
+      response->GetByteString(STUN_ATTR_REALM);
+  if (!realm_attr) {
+    LOG_J(LS_WARNING, port_) << "Missing STUN_ATTR_REALM attribute in "
+                             << "allocate unauthorized response.";
+    return;
+  }
+  port_->set_realm(realm_attr->GetString());
+
+  const StunByteStringAttribute* nonce_attr =
+      response->GetByteString(STUN_ATTR_NONCE);
+  if (!nonce_attr) {
+    LOG_J(LS_WARNING, port_) << "Missing STUN_ATTR_NONCE attribute in "
+                             << "allocate unauthorized response.";
+    return;
+  }
+  port_->set_nonce(nonce_attr->GetString());
+
+  // Send another allocate request, with the received realm and nonce values.
+  port_->SendRequest(new TurnAllocateRequest(port_), 0);
+}
+
+void TurnAllocateRequest::OnTryAlternate(StunMessage* response, int code) {
+  // TODO(guoweis): Currently, we only support UDP redirect
+  if (port_->server_address().proto != PROTO_UDP) {
+    LOG_J(LS_WARNING, port_) << "Receiving 300 Alternate Server on non-UDP "
+                         << "allocating request from ["
+                         << port_->server_address().address.ToSensitiveString()
+                         << "], failed as currently not supported";
+    port_->OnAllocateError();
+    return;
+  }
+
+  // According to RFC 5389 section 11, there are use cases where
+  // authentication of response is not possible, we're not validating
+  // message integrity.
+
+  // Get the alternate server address attribute value.
+  const StunAddressAttribute* alternate_server_attr =
+      response->GetAddress(STUN_ATTR_ALTERNATE_SERVER);
+  if (!alternate_server_attr) {
+    LOG_J(LS_WARNING, port_) << "Missing STUN_ATTR_ALTERNATE_SERVER "
+                             << "attribute in try alternate error response";
+    port_->OnAllocateError();
+    return;
+  }
+  if (!port_->SetAlternateServer(alternate_server_attr->GetAddress())) {
+    port_->OnAllocateError();
+    return;
+  }
+
+  // Check the attributes.
+  const StunByteStringAttribute* realm_attr =
+      response->GetByteString(STUN_ATTR_REALM);
+  if (realm_attr) {
+    LOG_J(LS_INFO, port_) << "Applying STUN_ATTR_REALM attribute in "
+                          << "try alternate error response.";
+    port_->set_realm(realm_attr->GetString());
+  }
+
+  const StunByteStringAttribute* nonce_attr =
+      response->GetByteString(STUN_ATTR_NONCE);
+  if (nonce_attr) {
+    LOG_J(LS_INFO, port_) << "Applying STUN_ATTR_NONCE attribute in "
+                          << "try alternate error response.";
+    port_->set_nonce(nonce_attr->GetString());
+  }
+
+  // Send another allocate request to alternate server,
+  // with the received realm and nonce values.
+  port_->SendRequest(new TurnAllocateRequest(port_), 0);
+}
+
+TurnRefreshRequest::TurnRefreshRequest(TurnPort* port)
+    : StunRequest(new TurnMessage()),
+      port_(port) {
+}
+
+void TurnRefreshRequest::Prepare(StunMessage* request) {
+  // Create the request as indicated in RFC 5766, Section 7.1.
+  // No attributes need to be included.
+  request->SetType(TURN_REFRESH_REQUEST);
+  port_->AddRequestAuthInfo(request);
+}
+
+void TurnRefreshRequest::OnResponse(StunMessage* response) {
+  // Check mandatory attributes as indicated in RFC5766, Section 7.3.
+  const StunUInt32Attribute* lifetime_attr =
+      response->GetUInt32(STUN_ATTR_TURN_LIFETIME);
+  if (!lifetime_attr) {
+    LOG_J(LS_WARNING, port_) << "Missing STUN_ATTR_TURN_LIFETIME attribute in "
+                             << "refresh success response.";
+    return;
+  }
+
+  // Schedule a refresh based on the returned lifetime value.
+  port_->ScheduleRefresh(lifetime_attr->value());
+}
+
+void TurnRefreshRequest::OnErrorResponse(StunMessage* response) {
+  const StunErrorCodeAttribute* error_code = response->GetErrorCode();
+  LOG_J(LS_WARNING, port_) << "Refresh response error, code="
+                           << error_code->code();
+
+  if (error_code->code() == STUN_ERROR_STALE_NONCE) {
+    if (port_->UpdateNonce(response)) {
+      // Send RefreshRequest immediately.
+      port_->SendRequest(new TurnRefreshRequest(port_), 0);
+    }
+  }
+}
+
+void TurnRefreshRequest::OnTimeout() {
+}
+
+TurnCreatePermissionRequest::TurnCreatePermissionRequest(
+    TurnPort* port, TurnEntry* entry,
+    const rtc::SocketAddress& ext_addr)
+    : StunRequest(new TurnMessage()),
+      port_(port),
+      entry_(entry),
+      ext_addr_(ext_addr) {
+  entry_->SignalDestroyed.connect(
+      this, &TurnCreatePermissionRequest::OnEntryDestroyed);
+}
+
+void TurnCreatePermissionRequest::Prepare(StunMessage* request) {
+  // Create the request as indicated in RFC5766, Section 9.1.
+  request->SetType(TURN_CREATE_PERMISSION_REQUEST);
+  VERIFY(request->AddAttribute(new StunXorAddressAttribute(
+      STUN_ATTR_XOR_PEER_ADDRESS, ext_addr_)));
+  port_->AddRequestAuthInfo(request);
+}
+
+void TurnCreatePermissionRequest::OnResponse(StunMessage* response) {
+  if (entry_) {
+    entry_->OnCreatePermissionSuccess();
+  }
+}
+
+void TurnCreatePermissionRequest::OnErrorResponse(StunMessage* response) {
+  if (entry_) {
+    const StunErrorCodeAttribute* error_code = response->GetErrorCode();
+    entry_->OnCreatePermissionError(response, error_code->code());
+  }
+}
+
+void TurnCreatePermissionRequest::OnTimeout() {
+  LOG_J(LS_WARNING, port_) << "Create permission timeout";
+}
+
+void TurnCreatePermissionRequest::OnEntryDestroyed(TurnEntry* entry) {
+  ASSERT(entry_ == entry);
+  entry_ = NULL;
+}
+
+TurnChannelBindRequest::TurnChannelBindRequest(
+    TurnPort* port, TurnEntry* entry,
+    int channel_id, const rtc::SocketAddress& ext_addr)
+    : StunRequest(new TurnMessage()),
+      port_(port),
+      entry_(entry),
+      channel_id_(channel_id),
+      ext_addr_(ext_addr) {
+  entry_->SignalDestroyed.connect(
+      this, &TurnChannelBindRequest::OnEntryDestroyed);
+}
+
+void TurnChannelBindRequest::Prepare(StunMessage* request) {
+  // Create the request as indicated in RFC5766, Section 11.1.
+  request->SetType(TURN_CHANNEL_BIND_REQUEST);
+  VERIFY(request->AddAttribute(new StunUInt32Attribute(
+      STUN_ATTR_CHANNEL_NUMBER, channel_id_ << 16)));
+  VERIFY(request->AddAttribute(new StunXorAddressAttribute(
+      STUN_ATTR_XOR_PEER_ADDRESS, ext_addr_)));
+  port_->AddRequestAuthInfo(request);
+}
+
+void TurnChannelBindRequest::OnResponse(StunMessage* response) {
+  if (entry_) {
+    entry_->OnChannelBindSuccess();
+    // Refresh the channel binding just under the permission timeout
+    // threshold. The channel binding has a longer lifetime, but
+    // this is the easiest way to keep both the channel and the
+    // permission from expiring.
+    entry_->SendChannelBindRequest(TURN_PERMISSION_TIMEOUT - 60 * 1000);
+  }
+}
+
+void TurnChannelBindRequest::OnErrorResponse(StunMessage* response) {
+  if (entry_) {
+    const StunErrorCodeAttribute* error_code = response->GetErrorCode();
+    entry_->OnChannelBindError(response, error_code->code());
+  }
+}
+
+void TurnChannelBindRequest::OnTimeout() {
+  LOG_J(LS_WARNING, port_) << "Channel bind timeout";
+}
+
+void TurnChannelBindRequest::OnEntryDestroyed(TurnEntry* entry) {
+  ASSERT(entry_ == entry);
+  entry_ = NULL;
+}
+
+TurnEntry::TurnEntry(TurnPort* port, int channel_id,
+                     const rtc::SocketAddress& ext_addr)
+    : port_(port),
+      channel_id_(channel_id),
+      ext_addr_(ext_addr),
+      state_(STATE_UNBOUND) {
+  // Creating permission for |ext_addr_|.
+  SendCreatePermissionRequest();
+}
+
+void TurnEntry::SendCreatePermissionRequest() {
+  port_->SendRequest(new TurnCreatePermissionRequest(
+      port_, this, ext_addr_), 0);
+}
+
+void TurnEntry::SendChannelBindRequest(int delay) {
+  port_->SendRequest(new TurnChannelBindRequest(
+      port_, this, channel_id_, ext_addr_), delay);
+}
+
+int TurnEntry::Send(const void* data, size_t size, bool payload,
+                    const rtc::PacketOptions& options) {
+  rtc::ByteBuffer buf;
+  if (state_ != STATE_BOUND) {
+    // If we haven't bound the channel yet, we have to use a Send Indication.
+    TurnMessage msg;
+    msg.SetType(TURN_SEND_INDICATION);
+    msg.SetTransactionID(
+        rtc::CreateRandomString(kStunTransactionIdLength));
+    VERIFY(msg.AddAttribute(new StunXorAddressAttribute(
+        STUN_ATTR_XOR_PEER_ADDRESS, ext_addr_)));
+    VERIFY(msg.AddAttribute(new StunByteStringAttribute(
+        STUN_ATTR_DATA, data, size)));
+    VERIFY(msg.Write(&buf));
+
+    // If we're sending real data, request a channel bind that we can use later.
+    if (state_ == STATE_UNBOUND && payload) {
+      SendChannelBindRequest(0);
+      state_ = STATE_BINDING;
+    }
+  } else {
+    // If the channel is bound, we can send the data as a Channel Message.
+    buf.WriteUInt16(channel_id_);
+    buf.WriteUInt16(static_cast<uint16>(size));
+    buf.WriteBytes(reinterpret_cast<const char*>(data), size);
+  }
+  return port_->Send(buf.Data(), buf.Length(), options);
+}
+
+void TurnEntry::OnCreatePermissionSuccess() {
+  LOG_J(LS_INFO, port_) << "Create permission for "
+                        << ext_addr_.ToSensitiveString()
+                        << " succeeded";
+  // For success result code will be 0.
+  port_->SignalCreatePermissionResult(port_, ext_addr_, 0);
+}
+
+void TurnEntry::OnCreatePermissionError(StunMessage* response, int code) {
+  LOG_J(LS_WARNING, port_) << "Create permission for "
+                           << ext_addr_.ToSensitiveString()
+                           << " failed, code=" << code;
+  if (code == STUN_ERROR_STALE_NONCE) {
+    if (port_->UpdateNonce(response)) {
+      SendCreatePermissionRequest();
+    }
+  } else {
+    // Send signal with error code.
+    port_->SignalCreatePermissionResult(port_, ext_addr_, code);
+  }
+}
+
+void TurnEntry::OnChannelBindSuccess() {
+  LOG_J(LS_INFO, port_) << "Channel bind for " << ext_addr_.ToSensitiveString()
+                        << " succeeded";
+  ASSERT(state_ == STATE_BINDING || state_ == STATE_BOUND);
+  state_ = STATE_BOUND;
+}
+
+void TurnEntry::OnChannelBindError(StunMessage* response, int code) {
+  // TODO(mallinath) - Implement handling of error response for channel
+  // bind request as per http://tools.ietf.org/html/rfc5766#section-11.3
+  LOG_J(LS_WARNING, port_) << "Channel bind for "
+                           << ext_addr_.ToSensitiveString()
+                           << " failed, code=" << code;
+  if (code == STUN_ERROR_STALE_NONCE) {
+    if (port_->UpdateNonce(response)) {
+      // Send channel bind request with fresh nonce.
+      SendChannelBindRequest(0);
+    }
+  }
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/turnport.h b/webrtc/p2p/base/turnport.h
new file mode 100644
index 0000000..17fad17
--- /dev/null
+++ b/webrtc/p2p/base/turnport.h
@@ -0,0 +1,237 @@
+/*
+ *  Copyright 2012 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_TURNPORT_H_
+#define WEBRTC_P2P_BASE_TURNPORT_H_
+
+#include <stdio.h>
+#include <list>
+#include <set>
+#include <string>
+
+#include "webrtc/p2p/base/port.h"
+#include "webrtc/p2p/client/basicportallocator.h"
+#include "webrtc/base/asyncpacketsocket.h"
+
+namespace rtc {
+class AsyncResolver;
+class SignalThread;
+}
+
+namespace cricket {
+
+extern const char TURN_PORT_TYPE[];
+class TurnAllocateRequest;
+class TurnEntry;
+
+class TurnPort : public Port {
+ public:
+  static TurnPort* Create(rtc::Thread* thread,
+                          rtc::PacketSocketFactory* factory,
+                          rtc::Network* network,
+                          rtc::AsyncPacketSocket* socket,
+                          const std::string& username,  // ice username.
+                          const std::string& password,  // ice password.
+                          const ProtocolAddress& server_address,
+                          const RelayCredentials& credentials,
+                          int server_priority) {
+    return new TurnPort(thread, factory, network, socket,
+                        username, password, server_address,
+                        credentials, server_priority);
+  }
+
+  static TurnPort* Create(rtc::Thread* thread,
+                          rtc::PacketSocketFactory* factory,
+                          rtc::Network* network,
+                          const rtc::IPAddress& ip,
+                          int min_port, int max_port,
+                          const std::string& username,  // ice username.
+                          const std::string& password,  // ice password.
+                          const ProtocolAddress& server_address,
+                          const RelayCredentials& credentials,
+                          int server_priority) {
+    return new TurnPort(thread, factory, network, ip, min_port, max_port,
+                        username, password, server_address, credentials,
+                        server_priority);
+  }
+
+  virtual ~TurnPort();
+
+  const ProtocolAddress& server_address() const { return server_address_; }
+
+  bool connected() const { return connected_; }
+  const RelayCredentials& credentials() const { return credentials_; }
+
+  virtual void PrepareAddress();
+  virtual Connection* CreateConnection(
+      const Candidate& c, PortInterface::CandidateOrigin origin);
+  virtual int SendTo(const void* data, size_t size,
+                     const rtc::SocketAddress& addr,
+                     const rtc::PacketOptions& options,
+                     bool payload);
+  virtual int SetOption(rtc::Socket::Option opt, int value);
+  virtual int GetOption(rtc::Socket::Option opt, int* value);
+  virtual int GetError();
+
+  virtual bool HandleIncomingPacket(
+      rtc::AsyncPacketSocket* socket, const char* data, size_t size,
+      const rtc::SocketAddress& remote_addr,
+      const rtc::PacketTime& packet_time) {
+    OnReadPacket(socket, data, size, remote_addr, packet_time);
+    return true;
+  }
+  virtual void OnReadPacket(rtc::AsyncPacketSocket* socket,
+                            const char* data, size_t size,
+                            const rtc::SocketAddress& remote_addr,
+                            const rtc::PacketTime& packet_time);
+
+  virtual void OnReadyToSend(rtc::AsyncPacketSocket* socket);
+
+  void OnSocketConnect(rtc::AsyncPacketSocket* socket);
+  void OnSocketClose(rtc::AsyncPacketSocket* socket, int error);
+
+
+  const std::string& hash() const { return hash_; }
+  const std::string& nonce() const { return nonce_; }
+
+  int error() const { return error_; }
+
+  void OnAllocateMismatch();
+
+  rtc::AsyncPacketSocket* socket() const {
+    return socket_;
+  }
+
+  // Signal with resolved server address.
+  // Parameters are port, server address and resolved server address.
+  // This signal will be sent only if server address is resolved successfully.
+  sigslot::signal3<TurnPort*,
+                   const rtc::SocketAddress&,
+                   const rtc::SocketAddress&> SignalResolvedServerAddress;
+
+  // This signal is only for testing purpose.
+  sigslot::signal3<TurnPort*, const rtc::SocketAddress&, int>
+      SignalCreatePermissionResult;
+
+ protected:
+  TurnPort(rtc::Thread* thread,
+           rtc::PacketSocketFactory* factory,
+           rtc::Network* network,
+           rtc::AsyncPacketSocket* socket,
+           const std::string& username,
+           const std::string& password,
+           const ProtocolAddress& server_address,
+           const RelayCredentials& credentials,
+           int server_priority);
+
+  TurnPort(rtc::Thread* thread,
+           rtc::PacketSocketFactory* factory,
+           rtc::Network* network,
+           const rtc::IPAddress& ip,
+           int min_port, int max_port,
+           const std::string& username,
+           const std::string& password,
+           const ProtocolAddress& server_address,
+           const RelayCredentials& credentials,
+           int server_priority);
+
+ private:
+  enum {
+    MSG_ERROR = MSG_FIRST_AVAILABLE,
+    MSG_ALLOCATE_MISMATCH
+  };
+
+  typedef std::list<TurnEntry*> EntryList;
+  typedef std::map<rtc::Socket::Option, int> SocketOptionsMap;
+  typedef std::set<rtc::SocketAddress> AttemptedServerSet;
+
+  virtual void OnMessage(rtc::Message* pmsg);
+
+  bool CreateTurnClientSocket();
+
+  void set_nonce(const std::string& nonce) { nonce_ = nonce; }
+  void set_realm(const std::string& realm) {
+    if (realm != realm_) {
+      realm_ = realm;
+      UpdateHash();
+    }
+  }
+
+  bool SetAlternateServer(const rtc::SocketAddress& address);
+  void ResolveTurnAddress(const rtc::SocketAddress& address);
+  void OnResolveResult(rtc::AsyncResolverInterface* resolver);
+
+  void AddRequestAuthInfo(StunMessage* msg);
+  void OnSendStunPacket(const void* data, size_t size, StunRequest* request);
+  // Stun address from allocate success response.
+  // Currently used only for testing.
+  void OnStunAddress(const rtc::SocketAddress& address);
+  void OnAllocateSuccess(const rtc::SocketAddress& address,
+                         const rtc::SocketAddress& stun_address);
+  void OnAllocateError();
+  void OnAllocateRequestTimeout();
+
+  void HandleDataIndication(const char* data, size_t size,
+                            const rtc::PacketTime& packet_time);
+  void HandleChannelData(int channel_id, const char* data, size_t size,
+                         const rtc::PacketTime& packet_time);
+  void DispatchPacket(const char* data, size_t size,
+      const rtc::SocketAddress& remote_addr,
+      ProtocolType proto, const rtc::PacketTime& packet_time);
+
+  bool ScheduleRefresh(int lifetime);
+  void SendRequest(StunRequest* request, int delay);
+  int Send(const void* data, size_t size,
+           const rtc::PacketOptions& options);
+  void UpdateHash();
+  bool UpdateNonce(StunMessage* response);
+
+  bool HasPermission(const rtc::IPAddress& ipaddr) const;
+  TurnEntry* FindEntry(const rtc::SocketAddress& address) const;
+  TurnEntry* FindEntry(int channel_id) const;
+  TurnEntry* CreateEntry(const rtc::SocketAddress& address);
+  void DestroyEntry(const rtc::SocketAddress& address);
+  void OnConnectionDestroyed(Connection* conn);
+
+  ProtocolAddress server_address_;
+  RelayCredentials credentials_;
+  AttemptedServerSet attempted_server_addresses_;
+
+  rtc::AsyncPacketSocket* socket_;
+  SocketOptionsMap socket_options_;
+  rtc::AsyncResolverInterface* resolver_;
+  int error_;
+
+  StunRequestManager request_manager_;
+  std::string realm_;       // From 401/438 response message.
+  std::string nonce_;       // From 401/438 response message.
+  std::string hash_;        // Digest of username:realm:password
+
+  int next_channel_number_;
+  EntryList entries_;
+
+  bool connected_;
+  // By default the value will be set to 0. This value will be used in
+  // calculating the candidate priority.
+  int server_priority_;
+
+  // The number of retries made due to allocate mismatch error.
+  size_t allocate_mismatch_retries_;
+
+  friend class TurnEntry;
+  friend class TurnAllocateRequest;
+  friend class TurnRefreshRequest;
+  friend class TurnCreatePermissionRequest;
+  friend class TurnChannelBindRequest;
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_TURNPORT_H_
diff --git a/webrtc/p2p/base/turnport_unittest.cc b/webrtc/p2p/base/turnport_unittest.cc
new file mode 100644
index 0000000..4b524d5
--- /dev/null
+++ b/webrtc/p2p/base/turnport_unittest.cc
@@ -0,0 +1,668 @@
+/*
+ *  Copyright 2012 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+#if defined(WEBRTC_POSIX)
+#include <dirent.h>
+#endif
+
+#include "webrtc/p2p/base/basicpacketsocketfactory.h"
+#include "webrtc/p2p/base/constants.h"
+#include "webrtc/p2p/base/tcpport.h"
+#include "webrtc/p2p/base/testturnserver.h"
+#include "webrtc/p2p/base/turnport.h"
+#include "webrtc/p2p/base/udpport.h"
+#include "webrtc/base/asynctcpsocket.h"
+#include "webrtc/base/buffer.h"
+#include "webrtc/base/dscp.h"
+#include "webrtc/base/firewallsocketserver.h"
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/helpers.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/physicalsocketserver.h"
+#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/socketaddress.h"
+#include "webrtc/base/ssladapter.h"
+#include "webrtc/base/thread.h"
+#include "webrtc/base/virtualsocketserver.h"
+
+using rtc::SocketAddress;
+using cricket::Connection;
+using cricket::Port;
+using cricket::PortInterface;
+using cricket::TurnPort;
+using cricket::UDPPort;
+
+static const SocketAddress kLocalAddr1("11.11.11.11", 0);
+static const SocketAddress kLocalAddr2("22.22.22.22", 0);
+static const SocketAddress kLocalIPv6Addr(
+    "2401:fa00:4:1000:be30:5bff:fee5:c3", 0);
+static const SocketAddress kTurnUdpIntAddr("99.99.99.3",
+                                           cricket::TURN_SERVER_PORT);
+static const SocketAddress kTurnTcpIntAddr("99.99.99.4",
+                                           cricket::TURN_SERVER_PORT);
+static const SocketAddress kTurnUdpExtAddr("99.99.99.5", 0);
+static const SocketAddress kTurnAlternateUdpIntAddr(
+    "99.99.99.6", cricket::TURN_SERVER_PORT);
+static const SocketAddress kTurnUdpIPv6IntAddr(
+    "2400:4030:1:2c00:be30:abcd:efab:cdef", cricket::TURN_SERVER_PORT);
+static const SocketAddress kTurnUdpIPv6ExtAddr(
+  "2620:0:1000:1b03:2e41:38ff:fea6:f2a4", 0);
+
+static const char kIceUfrag1[] = "TESTICEUFRAG0001";
+static const char kIceUfrag2[] = "TESTICEUFRAG0002";
+static const char kIcePwd1[] = "TESTICEPWD00000000000001";
+static const char kIcePwd2[] = "TESTICEPWD00000000000002";
+static const char kTurnUsername[] = "test";
+static const char kTurnPassword[] = "test";
+static const unsigned int kTimeout = 1000;
+
+static const cricket::ProtocolAddress kTurnUdpProtoAddr(
+    kTurnUdpIntAddr, cricket::PROTO_UDP);
+static const cricket::ProtocolAddress kTurnTcpProtoAddr(
+    kTurnTcpIntAddr, cricket::PROTO_TCP);
+static const cricket::ProtocolAddress kTurnUdpIPv6ProtoAddr(
+    kTurnUdpIPv6IntAddr, cricket::PROTO_UDP);
+
+static const unsigned int MSG_TESTFINISH = 0;
+
+#if defined(WEBRTC_LINUX) && !defined(WEBRTC_ANDROID)
+static int GetFDCount() {
+  struct dirent *dp;
+  int fd_count = 0;
+  DIR *dir = opendir("/proc/self/fd/");
+  while ((dp = readdir(dir)) != NULL) {
+    if (dp->d_name[0] == '.')
+      continue;
+    ++fd_count;
+  }
+  closedir(dir);
+  return fd_count;
+}
+#endif
+
+class TurnPortTest : public testing::Test,
+                     public sigslot::has_slots<>,
+                     public rtc::MessageHandler {
+ public:
+  TurnPortTest()
+      : main_(rtc::Thread::Current()),
+        pss_(new rtc::PhysicalSocketServer),
+        ss_(new rtc::VirtualSocketServer(pss_.get())),
+        ss_scope_(ss_.get()),
+        network_("unittest", "unittest", rtc::IPAddress(INADDR_ANY), 32),
+        socket_factory_(rtc::Thread::Current()),
+        turn_server_(main_, kTurnUdpIntAddr, kTurnUdpExtAddr),
+        turn_ready_(false),
+        turn_error_(false),
+        turn_unknown_address_(false),
+        turn_create_permission_success_(false),
+        udp_ready_(false),
+        test_finish_(false) {
+    network_.AddIP(rtc::IPAddress(INADDR_ANY));
+  }
+
+  virtual void OnMessage(rtc::Message* msg) {
+    ASSERT(msg->message_id == MSG_TESTFINISH);
+    if (msg->message_id == MSG_TESTFINISH)
+      test_finish_ = true;
+  }
+
+  void OnTurnPortComplete(Port* port) {
+    turn_ready_ = true;
+  }
+  void OnTurnPortError(Port* port) {
+    turn_error_ = true;
+  }
+  void OnTurnUnknownAddress(PortInterface* port, const SocketAddress& addr,
+                            cricket::ProtocolType proto,
+                            cricket::IceMessage* msg, const std::string& rf,
+                            bool /*port_muxed*/) {
+    turn_unknown_address_ = true;
+  }
+  void OnTurnCreatePermissionResult(TurnPort* port, const SocketAddress& addr,
+                                     int code) {
+    // Ignoring the address.
+    if (code == 0) {
+      turn_create_permission_success_ = true;
+    }
+  }
+  void OnTurnReadPacket(Connection* conn, const char* data, size_t size,
+                        const rtc::PacketTime& packet_time) {
+    turn_packets_.push_back(rtc::Buffer(data, size));
+  }
+  void OnUdpPortComplete(Port* port) {
+    udp_ready_ = true;
+  }
+  void OnUdpReadPacket(Connection* conn, const char* data, size_t size,
+                       const rtc::PacketTime& packet_time) {
+    udp_packets_.push_back(rtc::Buffer(data, size));
+  }
+  void OnSocketReadPacket(rtc::AsyncPacketSocket* socket,
+                          const char* data, size_t size,
+                          const rtc::SocketAddress& remote_addr,
+                          const rtc::PacketTime& packet_time) {
+    turn_port_->HandleIncomingPacket(socket, data, size, remote_addr,
+                                     packet_time);
+  }
+  rtc::AsyncSocket* CreateServerSocket(const SocketAddress addr) {
+    rtc::AsyncSocket* socket = ss_->CreateAsyncSocket(SOCK_STREAM);
+    EXPECT_GE(socket->Bind(addr), 0);
+    EXPECT_GE(socket->Listen(5), 0);
+    return socket;
+  }
+
+  void CreateTurnPort(const std::string& username,
+                      const std::string& password,
+                      const cricket::ProtocolAddress& server_address) {
+    CreateTurnPort(kLocalAddr1, username, password, server_address);
+  }
+  void CreateTurnPort(const rtc::SocketAddress& local_address,
+                      const std::string& username,
+                      const std::string& password,
+                      const cricket::ProtocolAddress& server_address) {
+    cricket::RelayCredentials credentials(username, password);
+    turn_port_.reset(TurnPort::Create(main_, &socket_factory_, &network_,
+                                 local_address.ipaddr(), 0, 0,
+                                 kIceUfrag1, kIcePwd1,
+                                 server_address, credentials, 0));
+    // Set ICE protocol type to ICEPROTO_RFC5245, as port by default will be
+    // in Hybrid mode. Protocol type is necessary to send correct type STUN ping
+    // messages.
+    // This TURN port will be the controlling.
+    turn_port_->SetIceProtocolType(cricket::ICEPROTO_RFC5245);
+    turn_port_->SetIceRole(cricket::ICEROLE_CONTROLLING);
+    ConnectSignals();
+  }
+
+  void CreateSharedTurnPort(const std::string& username,
+                            const std::string& password,
+                            const cricket::ProtocolAddress& server_address) {
+    ASSERT(server_address.proto == cricket::PROTO_UDP);
+
+    if (!socket_) {
+      socket_.reset(socket_factory_.CreateUdpSocket(
+          rtc::SocketAddress(kLocalAddr1.ipaddr(), 0), 0, 0));
+      ASSERT_TRUE(socket_ != NULL);
+      socket_->SignalReadPacket.connect(
+          this, &TurnPortTest::OnSocketReadPacket);
+    }
+
+    cricket::RelayCredentials credentials(username, password);
+    turn_port_.reset(cricket::TurnPort::Create(
+        main_, &socket_factory_, &network_, socket_.get(),
+        kIceUfrag1, kIcePwd1, server_address, credentials, 0));
+    // Set ICE protocol type to ICEPROTO_RFC5245, as port by default will be
+    // in Hybrid mode. Protocol type is necessary to send correct type STUN ping
+    // messages.
+    // This TURN port will be the controlling.
+    turn_port_->SetIceProtocolType(cricket::ICEPROTO_RFC5245);
+    turn_port_->SetIceRole(cricket::ICEROLE_CONTROLLING);
+    ConnectSignals();
+  }
+
+  void ConnectSignals() {
+    turn_port_->SignalPortComplete.connect(this,
+        &TurnPortTest::OnTurnPortComplete);
+    turn_port_->SignalPortError.connect(this,
+        &TurnPortTest::OnTurnPortError);
+    turn_port_->SignalUnknownAddress.connect(this,
+        &TurnPortTest::OnTurnUnknownAddress);
+    turn_port_->SignalCreatePermissionResult.connect(this,
+        &TurnPortTest::OnTurnCreatePermissionResult);
+  }
+  void CreateUdpPort() {
+    udp_port_.reset(UDPPort::Create(main_, &socket_factory_, &network_,
+                                    kLocalAddr2.ipaddr(), 0, 0,
+                                    kIceUfrag2, kIcePwd2));
+    // Set protocol type to RFC5245, as turn port is also in same mode.
+    // UDP port will be controlled.
+    udp_port_->SetIceProtocolType(cricket::ICEPROTO_RFC5245);
+    udp_port_->SetIceRole(cricket::ICEROLE_CONTROLLED);
+    udp_port_->SignalPortComplete.connect(
+        this, &TurnPortTest::OnUdpPortComplete);
+  }
+
+  void TestTurnConnection() {
+    // Create ports and prepare addresses.
+    ASSERT_TRUE(turn_port_ != NULL);
+    turn_port_->PrepareAddress();
+    ASSERT_TRUE_WAIT(turn_ready_, kTimeout);
+    CreateUdpPort();
+    udp_port_->PrepareAddress();
+    ASSERT_TRUE_WAIT(udp_ready_, kTimeout);
+
+    // Send ping from UDP to TURN.
+    Connection* conn1 = udp_port_->CreateConnection(
+                    turn_port_->Candidates()[0], Port::ORIGIN_MESSAGE);
+    ASSERT_TRUE(conn1 != NULL);
+    conn1->Ping(0);
+    WAIT(!turn_unknown_address_, kTimeout);
+    EXPECT_FALSE(turn_unknown_address_);
+    EXPECT_EQ(Connection::STATE_READ_INIT, conn1->read_state());
+    EXPECT_EQ(Connection::STATE_WRITE_INIT, conn1->write_state());
+
+    // Send ping from TURN to UDP.
+    Connection* conn2 = turn_port_->CreateConnection(
+                    udp_port_->Candidates()[0], Port::ORIGIN_MESSAGE);
+    ASSERT_TRUE(conn2 != NULL);
+    ASSERT_TRUE_WAIT(turn_create_permission_success_, kTimeout);
+    conn2->Ping(0);
+
+    EXPECT_EQ_WAIT(Connection::STATE_WRITABLE, conn2->write_state(), kTimeout);
+    EXPECT_EQ(Connection::STATE_READABLE, conn1->read_state());
+    EXPECT_EQ(Connection::STATE_READ_INIT, conn2->read_state());
+    EXPECT_EQ(Connection::STATE_WRITE_INIT, conn1->write_state());
+
+    // Send another ping from UDP to TURN.
+    conn1->Ping(0);
+    EXPECT_EQ_WAIT(Connection::STATE_WRITABLE, conn1->write_state(), kTimeout);
+    EXPECT_EQ(Connection::STATE_READABLE, conn2->read_state());
+  }
+
+  void TestTurnSendData() {
+    turn_port_->PrepareAddress();
+    EXPECT_TRUE_WAIT(turn_ready_, kTimeout);
+    CreateUdpPort();
+    udp_port_->PrepareAddress();
+    EXPECT_TRUE_WAIT(udp_ready_, kTimeout);
+    // Create connections and send pings.
+    Connection* conn1 = turn_port_->CreateConnection(
+        udp_port_->Candidates()[0], Port::ORIGIN_MESSAGE);
+    Connection* conn2 = udp_port_->CreateConnection(
+        turn_port_->Candidates()[0], Port::ORIGIN_MESSAGE);
+    ASSERT_TRUE(conn1 != NULL);
+    ASSERT_TRUE(conn2 != NULL);
+    conn1->SignalReadPacket.connect(static_cast<TurnPortTest*>(this),
+                                    &TurnPortTest::OnTurnReadPacket);
+    conn2->SignalReadPacket.connect(static_cast<TurnPortTest*>(this),
+                                    &TurnPortTest::OnUdpReadPacket);
+    conn1->Ping(0);
+    EXPECT_EQ_WAIT(Connection::STATE_WRITABLE, conn1->write_state(), kTimeout);
+    conn2->Ping(0);
+    EXPECT_EQ_WAIT(Connection::STATE_WRITABLE, conn2->write_state(), kTimeout);
+
+    // Send some data.
+    size_t num_packets = 256;
+    for (size_t i = 0; i < num_packets; ++i) {
+      unsigned char buf[256] = { 0 };
+      for (size_t j = 0; j < i + 1; ++j) {
+        buf[j] = 0xFF - static_cast<unsigned char>(j);
+      }
+      conn1->Send(buf, i + 1, options);
+      conn2->Send(buf, i + 1, options);
+      main_->ProcessMessages(0);
+    }
+
+    // Check the data.
+    ASSERT_EQ_WAIT(num_packets, turn_packets_.size(), kTimeout);
+    ASSERT_EQ_WAIT(num_packets, udp_packets_.size(), kTimeout);
+    for (size_t i = 0; i < num_packets; ++i) {
+      EXPECT_EQ(i + 1, turn_packets_[i].length());
+      EXPECT_EQ(i + 1, udp_packets_[i].length());
+      EXPECT_EQ(turn_packets_[i], udp_packets_[i]);
+    }
+  }
+
+ protected:
+  rtc::Thread* main_;
+  rtc::scoped_ptr<rtc::PhysicalSocketServer> pss_;
+  rtc::scoped_ptr<rtc::VirtualSocketServer> ss_;
+  rtc::SocketServerScope ss_scope_;
+  rtc::Network network_;
+  rtc::BasicPacketSocketFactory socket_factory_;
+  rtc::scoped_ptr<rtc::AsyncPacketSocket> socket_;
+  cricket::TestTurnServer turn_server_;
+  rtc::scoped_ptr<TurnPort> turn_port_;
+  rtc::scoped_ptr<UDPPort> udp_port_;
+  bool turn_ready_;
+  bool turn_error_;
+  bool turn_unknown_address_;
+  bool turn_create_permission_success_;
+  bool udp_ready_;
+  bool test_finish_;
+  std::vector<rtc::Buffer> turn_packets_;
+  std::vector<rtc::Buffer> udp_packets_;
+  rtc::PacketOptions options;
+};
+
+// Do a normal TURN allocation.
+TEST_F(TurnPortTest, TestTurnAllocate) {
+  CreateTurnPort(kTurnUsername, kTurnPassword, kTurnUdpProtoAddr);
+  EXPECT_EQ(0, turn_port_->SetOption(rtc::Socket::OPT_SNDBUF, 10*1024));
+  turn_port_->PrepareAddress();
+  EXPECT_TRUE_WAIT(turn_ready_, kTimeout);
+  ASSERT_EQ(1U, turn_port_->Candidates().size());
+  EXPECT_EQ(kTurnUdpExtAddr.ipaddr(),
+            turn_port_->Candidates()[0].address().ipaddr());
+  EXPECT_NE(0, turn_port_->Candidates()[0].address().port());
+}
+
+// Testing a normal UDP allocation using TCP connection.
+TEST_F(TurnPortTest, TestTurnTcpAllocate) {
+  turn_server_.AddInternalSocket(kTurnTcpIntAddr, cricket::PROTO_TCP);
+  CreateTurnPort(kTurnUsername, kTurnPassword, kTurnTcpProtoAddr);
+  EXPECT_EQ(0, turn_port_->SetOption(rtc::Socket::OPT_SNDBUF, 10*1024));
+  turn_port_->PrepareAddress();
+  EXPECT_TRUE_WAIT(turn_ready_, kTimeout);
+  ASSERT_EQ(1U, turn_port_->Candidates().size());
+  EXPECT_EQ(kTurnUdpExtAddr.ipaddr(),
+            turn_port_->Candidates()[0].address().ipaddr());
+  EXPECT_NE(0, turn_port_->Candidates()[0].address().port());
+}
+
+// Testing turn port will attempt to create TCP socket on address resolution
+// failure.
+TEST_F(TurnPortTest, DISABLED_TestTurnTcpOnAddressResolveFailure) {
+  turn_server_.AddInternalSocket(kTurnTcpIntAddr, cricket::PROTO_TCP);
+  CreateTurnPort(kTurnUsername, kTurnPassword, cricket::ProtocolAddress(
+      rtc::SocketAddress("www.webrtc-blah-blah.com", 3478),
+      cricket::PROTO_TCP));
+  turn_port_->PrepareAddress();
+  EXPECT_TRUE_WAIT(turn_error_, kTimeout);
+  // As VSS doesn't provide a DNS resolution, name resolve will fail. TurnPort
+  // will proceed in creating a TCP socket which will fail as there is no
+  // server on the above domain and error will be set to SOCKET_ERROR.
+  EXPECT_EQ(SOCKET_ERROR, turn_port_->error());
+}
+
+// In case of UDP on address resolve failure, TurnPort will not create socket
+// and return allocate failure.
+TEST_F(TurnPortTest, DISABLED_TestTurnUdpOnAdressResolveFailure) {
+  CreateTurnPort(kTurnUsername, kTurnPassword, cricket::ProtocolAddress(
+      rtc::SocketAddress("www.webrtc-blah-blah.com", 3478),
+      cricket::PROTO_UDP));
+  turn_port_->PrepareAddress();
+  EXPECT_TRUE_WAIT(turn_error_, kTimeout);
+  // Error from turn port will not be socket error.
+  EXPECT_NE(SOCKET_ERROR, turn_port_->error());
+}
+
+// Try to do a TURN allocation with an invalid password.
+TEST_F(TurnPortTest, TestTurnAllocateBadPassword) {
+  CreateTurnPort(kTurnUsername, "bad", kTurnUdpProtoAddr);
+  turn_port_->PrepareAddress();
+  EXPECT_TRUE_WAIT(turn_error_, kTimeout);
+  ASSERT_EQ(0U, turn_port_->Candidates().size());
+}
+
+// Tests that a new local address is created after
+// STUN_ERROR_ALLOCATION_MISMATCH.
+TEST_F(TurnPortTest, TestTurnAllocateMismatch) {
+  // Do a normal allocation first.
+  CreateTurnPort(kTurnUsername, kTurnPassword, kTurnUdpProtoAddr);
+  turn_port_->PrepareAddress();
+  EXPECT_TRUE_WAIT(turn_ready_, kTimeout);
+  rtc::SocketAddress first_addr(turn_port_->socket()->GetLocalAddress());
+
+  // Forces the socket server to assign the same port.
+  ss_->SetNextPortForTesting(first_addr.port());
+
+  turn_ready_ = false;
+  CreateTurnPort(kTurnUsername, kTurnPassword, kTurnUdpProtoAddr);
+  turn_port_->PrepareAddress();
+
+  // Verifies that the new port has the same address.
+  EXPECT_EQ(first_addr, turn_port_->socket()->GetLocalAddress());
+
+  EXPECT_TRUE_WAIT(turn_ready_, kTimeout);
+
+  // Verifies that the new port has a different address now.
+  EXPECT_NE(first_addr, turn_port_->socket()->GetLocalAddress());
+}
+
+// Tests that a shared-socket-TurnPort creates its own socket after
+// STUN_ERROR_ALLOCATION_MISMATCH.
+TEST_F(TurnPortTest, TestSharedSocketAllocateMismatch) {
+  // Do a normal allocation first.
+  CreateSharedTurnPort(kTurnUsername, kTurnPassword, kTurnUdpProtoAddr);
+  turn_port_->PrepareAddress();
+  EXPECT_TRUE_WAIT(turn_ready_, kTimeout);
+  rtc::SocketAddress first_addr(turn_port_->socket()->GetLocalAddress());
+
+  turn_ready_ = false;
+  CreateSharedTurnPort(kTurnUsername, kTurnPassword, kTurnUdpProtoAddr);
+
+  // Verifies that the new port has the same address.
+  EXPECT_EQ(first_addr, turn_port_->socket()->GetLocalAddress());
+  EXPECT_TRUE(turn_port_->SharedSocket());
+
+  turn_port_->PrepareAddress();
+  EXPECT_TRUE_WAIT(turn_ready_, kTimeout);
+
+  // Verifies that the new port has a different address now.
+  EXPECT_NE(first_addr, turn_port_->socket()->GetLocalAddress());
+  EXPECT_FALSE(turn_port_->SharedSocket());
+}
+
+TEST_F(TurnPortTest, TestTurnTcpAllocateMismatch) {
+  turn_server_.AddInternalSocket(kTurnTcpIntAddr, cricket::PROTO_TCP);
+  CreateTurnPort(kTurnUsername, kTurnPassword, kTurnTcpProtoAddr);
+
+  // Do a normal allocation first.
+  turn_port_->PrepareAddress();
+  EXPECT_TRUE_WAIT(turn_ready_, kTimeout);
+  rtc::SocketAddress first_addr(turn_port_->socket()->GetLocalAddress());
+
+  // Forces the socket server to assign the same port.
+  ss_->SetNextPortForTesting(first_addr.port());
+
+  turn_ready_ = false;
+  CreateTurnPort(kTurnUsername, kTurnPassword, kTurnTcpProtoAddr);
+  turn_port_->PrepareAddress();
+
+  // Verifies that the new port has the same address.
+  EXPECT_EQ(first_addr, turn_port_->socket()->GetLocalAddress());
+
+  EXPECT_TRUE_WAIT(turn_ready_, kTimeout);
+
+  // Verifies that the new port has a different address now.
+  EXPECT_NE(first_addr, turn_port_->socket()->GetLocalAddress());
+}
+
+// Do a TURN allocation and try to send a packet to it from the outside.
+// The packet should be dropped. Then, try to send a packet from TURN to the
+// outside. It should reach its destination. Finally, try again from the
+// outside. It should now work as well.
+TEST_F(TurnPortTest, TestTurnConnection) {
+  CreateTurnPort(kTurnUsername, kTurnPassword, kTurnUdpProtoAddr);
+  TestTurnConnection();
+}
+
+// Similar to above, except that this test will use the shared socket.
+TEST_F(TurnPortTest, TestTurnConnectionUsingSharedSocket) {
+  CreateSharedTurnPort(kTurnUsername, kTurnPassword, kTurnUdpProtoAddr);
+  TestTurnConnection();
+}
+
+// Test that we can establish a TCP connection with TURN server.
+TEST_F(TurnPortTest, TestTurnTcpConnection) {
+  turn_server_.AddInternalSocket(kTurnTcpIntAddr, cricket::PROTO_TCP);
+  CreateTurnPort(kTurnUsername, kTurnPassword, kTurnTcpProtoAddr);
+  TestTurnConnection();
+}
+
+// Test that we fail to create a connection when we want to use TLS over TCP.
+// This test should be removed once we have TLS support.
+TEST_F(TurnPortTest, TestTurnTlsTcpConnectionFails) {
+  cricket::ProtocolAddress secure_addr(kTurnTcpProtoAddr.address,
+                                       kTurnTcpProtoAddr.proto,
+                                       true);
+  CreateTurnPort(kTurnUsername, kTurnPassword, secure_addr);
+  turn_port_->PrepareAddress();
+  EXPECT_TRUE_WAIT(turn_error_, kTimeout);
+  ASSERT_EQ(0U, turn_port_->Candidates().size());
+}
+
+// Test try-alternate-server feature.
+TEST_F(TurnPortTest, TestTurnAlternateServer) {
+  std::vector<rtc::SocketAddress> redirect_addresses;
+  redirect_addresses.push_back(kTurnAlternateUdpIntAddr);
+
+  cricket::TestTurnRedirector redirector(redirect_addresses);
+  turn_server_.AddInternalSocket(kTurnAlternateUdpIntAddr,
+                                 cricket::PROTO_UDP);
+  turn_server_.set_redirect_hook(&redirector);
+  CreateTurnPort(kTurnUsername, kTurnPassword, kTurnUdpProtoAddr);
+
+  // Retrieve the address before we run the state machine.
+  const SocketAddress old_addr = turn_port_->server_address().address;
+
+  turn_port_->PrepareAddress();
+  EXPECT_TRUE_WAIT(turn_ready_, kTimeout);
+  // Retrieve the address again, the turn port's address should be
+  // changed.
+  const SocketAddress new_addr = turn_port_->server_address().address;
+  EXPECT_NE(old_addr, new_addr);
+  ASSERT_EQ(1U, turn_port_->Candidates().size());
+  EXPECT_EQ(kTurnUdpExtAddr.ipaddr(),
+            turn_port_->Candidates()[0].address().ipaddr());
+  EXPECT_NE(0, turn_port_->Candidates()[0].address().port());
+}
+
+// Test that we fail when we redirect to an address different from
+// current IP family.
+TEST_F(TurnPortTest, TestTurnAlternateServerV4toV6) {
+  std::vector<rtc::SocketAddress> redirect_addresses;
+  redirect_addresses.push_back(kTurnUdpIPv6IntAddr);
+
+  cricket::TestTurnRedirector redirector(redirect_addresses);
+  turn_server_.AddInternalSocket(kTurnAlternateUdpIntAddr,
+                                 cricket::PROTO_UDP);
+  turn_server_.set_redirect_hook(&redirector);
+  CreateTurnPort(kTurnUsername, kTurnPassword, kTurnUdpProtoAddr);
+  turn_port_->PrepareAddress();
+  EXPECT_TRUE_WAIT(turn_error_, kTimeout);
+}
+
+// Test that we fail to handle alternate-server response over TCP protocol.
+TEST_F(TurnPortTest, TestTurnAlternateServerTcp) {
+  std::vector<rtc::SocketAddress> redirect_addresses;
+  redirect_addresses.push_back(kTurnAlternateUdpIntAddr);
+
+  cricket::TestTurnRedirector redirector(redirect_addresses);
+  turn_server_.set_redirect_hook(&redirector);
+  turn_server_.AddInternalSocket(kTurnTcpIntAddr, cricket::PROTO_TCP);
+  CreateTurnPort(kTurnUsername, kTurnPassword, kTurnTcpProtoAddr);
+
+  turn_server_.AddInternalSocket(kTurnAlternateUdpIntAddr, cricket::PROTO_TCP);
+  turn_port_->PrepareAddress();
+  EXPECT_TRUE_WAIT(turn_error_, kTimeout);
+}
+
+// Test try-alternate-server catches the case of pingpong.
+TEST_F(TurnPortTest, TestTurnAlternateServerPingPong) {
+  std::vector<rtc::SocketAddress> redirect_addresses;
+  redirect_addresses.push_back(kTurnAlternateUdpIntAddr);
+  redirect_addresses.push_back(kTurnUdpIntAddr);
+
+  cricket::TestTurnRedirector redirector(redirect_addresses);
+
+  turn_server_.AddInternalSocket(kTurnAlternateUdpIntAddr,
+                                 cricket::PROTO_UDP);
+  turn_server_.set_redirect_hook(&redirector);
+  CreateTurnPort(kTurnUsername, kTurnPassword, kTurnUdpProtoAddr);
+
+  turn_port_->PrepareAddress();
+  EXPECT_TRUE_WAIT(turn_error_, kTimeout);
+  ASSERT_EQ(0U, turn_port_->Candidates().size());
+  rtc::SocketAddress address;
+  // Verify that we have exhausted all alternate servers instead of
+  // failure caused by other errors.
+  EXPECT_FALSE(redirector.ShouldRedirect(address, &address));
+}
+
+// Test try-alternate-server catch the case of repeated server.
+TEST_F(TurnPortTest, TestTurnAlternateServerDetectRepetition) {
+  std::vector<rtc::SocketAddress> redirect_addresses;
+  redirect_addresses.push_back(kTurnAlternateUdpIntAddr);
+  redirect_addresses.push_back(kTurnAlternateUdpIntAddr);
+
+  cricket::TestTurnRedirector redirector(redirect_addresses);
+
+  turn_server_.AddInternalSocket(kTurnAlternateUdpIntAddr,
+                                 cricket::PROTO_UDP);
+  turn_server_.set_redirect_hook(&redirector);
+  CreateTurnPort(kTurnUsername, kTurnPassword, kTurnUdpProtoAddr);
+
+  turn_port_->PrepareAddress();
+  EXPECT_TRUE_WAIT(turn_error_, kTimeout);
+  ASSERT_EQ(0U, turn_port_->Candidates().size());
+}
+
+
+// Run TurnConnectionTest with one-time-use nonce feature.
+// Here server will send a 438 STALE_NONCE error message for
+// every TURN transaction.
+TEST_F(TurnPortTest, TestTurnConnectionUsingOTUNonce) {
+  turn_server_.set_enable_otu_nonce(true);
+  CreateTurnPort(kTurnUsername, kTurnPassword, kTurnUdpProtoAddr);
+  TestTurnConnection();
+}
+
+// Do a TURN allocation, establish a UDP connection, and send some data.
+TEST_F(TurnPortTest, TestTurnSendDataTurnUdpToUdp) {
+  // Create ports and prepare addresses.
+  CreateTurnPort(kTurnUsername, kTurnPassword, kTurnUdpProtoAddr);
+  TestTurnSendData();
+}
+
+// Do a TURN allocation, establish a TCP connection, and send some data.
+TEST_F(TurnPortTest, TestTurnSendDataTurnTcpToUdp) {
+  turn_server_.AddInternalSocket(kTurnTcpIntAddr, cricket::PROTO_TCP);
+  // Create ports and prepare addresses.
+  CreateTurnPort(kTurnUsername, kTurnPassword, kTurnTcpProtoAddr);
+  TestTurnSendData();
+}
+
+// Test TURN fails to make a connection from IPv6 address to a server which has
+// IPv4 address.
+TEST_F(TurnPortTest, TestTurnLocalIPv6AddressServerIPv4) {
+  turn_server_.AddInternalSocket(kTurnUdpIPv6IntAddr, cricket::PROTO_UDP);
+  CreateTurnPort(kLocalIPv6Addr, kTurnUsername, kTurnPassword,
+                 kTurnUdpProtoAddr);
+  turn_port_->PrepareAddress();
+  ASSERT_TRUE_WAIT(turn_error_, kTimeout);
+  EXPECT_TRUE(turn_port_->Candidates().empty());
+}
+
+// Test TURN make a connection from IPv6 address to a server which has
+// IPv6 intenal address. But in this test external address is a IPv4 address,
+// hence allocated address will be a IPv4 address.
+TEST_F(TurnPortTest, TestTurnLocalIPv6AddressServerIPv6ExtenalIPv4) {
+  turn_server_.AddInternalSocket(kTurnUdpIPv6IntAddr, cricket::PROTO_UDP);
+  CreateTurnPort(kLocalIPv6Addr, kTurnUsername, kTurnPassword,
+                 kTurnUdpIPv6ProtoAddr);
+  turn_port_->PrepareAddress();
+  EXPECT_TRUE_WAIT(turn_ready_, kTimeout);
+  ASSERT_EQ(1U, turn_port_->Candidates().size());
+  EXPECT_EQ(kTurnUdpExtAddr.ipaddr(),
+            turn_port_->Candidates()[0].address().ipaddr());
+  EXPECT_NE(0, turn_port_->Candidates()[0].address().port());
+}
+
+// This test verifies any FD's are not leaked after TurnPort is destroyed.
+// https://code.google.com/p/webrtc/issues/detail?id=2651
+#if defined(WEBRTC_LINUX) && !defined(WEBRTC_ANDROID)
+TEST_F(TurnPortTest, TestResolverShutdown) {
+  turn_server_.AddInternalSocket(kTurnUdpIPv6IntAddr, cricket::PROTO_UDP);
+  int last_fd_count = GetFDCount();
+  // Need to supply unresolved address to kick off resolver.
+  CreateTurnPort(kLocalIPv6Addr, kTurnUsername, kTurnPassword,
+                 cricket::ProtocolAddress(rtc::SocketAddress(
+                    "stun.l.google.com", 3478), cricket::PROTO_UDP));
+  turn_port_->PrepareAddress();
+  ASSERT_TRUE_WAIT(turn_error_, kTimeout);
+  EXPECT_TRUE(turn_port_->Candidates().empty());
+  turn_port_.reset();
+  rtc::Thread::Current()->Post(this, MSG_TESTFINISH);
+  // Waiting for above message to be processed.
+  ASSERT_TRUE_WAIT(test_finish_, kTimeout);
+  EXPECT_EQ(last_fd_count, GetFDCount());
+}
+#endif
diff --git a/webrtc/p2p/base/turnserver.cc b/webrtc/p2p/base/turnserver.cc
new file mode 100644
index 0000000..8605e98
--- /dev/null
+++ b/webrtc/p2p/base/turnserver.cc
@@ -0,0 +1,1011 @@
+/*
+ *  Copyright 2012 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/turnserver.h"
+
+#include "webrtc/p2p/base/asyncstuntcpsocket.h"
+#include "webrtc/p2p/base/common.h"
+#include "webrtc/p2p/base/packetsocketfactory.h"
+#include "webrtc/p2p/base/stun.h"
+#include "webrtc/base/bytebuffer.h"
+#include "webrtc/base/helpers.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/messagedigest.h"
+#include "webrtc/base/socketadapters.h"
+#include "webrtc/base/stringencode.h"
+#include "webrtc/base/thread.h"
+
+namespace cricket {
+
+// TODO(juberti): Move this all to a future turnmessage.h
+//static const int IPPROTO_UDP = 17;
+static const int kNonceTimeout = 60 * 60 * 1000;              // 60 minutes
+static const int kDefaultAllocationTimeout = 10 * 60 * 1000;  // 10 minutes
+static const int kPermissionTimeout = 5 * 60 * 1000;          //  5 minutes
+static const int kChannelTimeout = 10 * 60 * 1000;            // 10 minutes
+
+static const int kMinChannelNumber = 0x4000;
+static const int kMaxChannelNumber = 0x7FFF;
+
+static const size_t kNonceKeySize = 16;
+static const size_t kNonceSize = 40;
+
+static const size_t TURN_CHANNEL_HEADER_SIZE = 4U;
+
+// TODO(mallinath) - Move these to a common place.
+inline bool IsTurnChannelData(uint16 msg_type) {
+  // The first two bits of a channel data message are 0b01.
+  return ((msg_type & 0xC000) == 0x4000);
+}
+
+// IDs used for posted messages for TurnServer::Allocation.
+enum {
+  MSG_ALLOCATION_TIMEOUT,
+};
+
+// Encapsulates a TURN allocation.
+// The object is created when an allocation request is received, and then
+// handles TURN messages (via HandleTurnMessage) and channel data messages
+// (via HandleChannelData) for this allocation when received by the server.
+// The object self-deletes and informs the server if its lifetime timer expires.
+class TurnServer::Allocation : public rtc::MessageHandler,
+                               public sigslot::has_slots<> {
+ public:
+  Allocation(TurnServer* server_,
+             rtc::Thread* thread, const Connection& conn,
+             rtc::AsyncPacketSocket* server_socket,
+             const std::string& key);
+  virtual ~Allocation();
+
+  Connection* conn() { return &conn_; }
+  const std::string& key() const { return key_; }
+  const std::string& transaction_id() const { return transaction_id_; }
+  const std::string& username() const { return username_; }
+  const std::string& last_nonce() const { return last_nonce_; }
+  void set_last_nonce(const std::string& nonce) { last_nonce_ = nonce; }
+
+  std::string ToString() const;
+
+  void HandleTurnMessage(const TurnMessage* msg);
+  void HandleChannelData(const char* data, size_t size);
+
+  sigslot::signal1<Allocation*> SignalDestroyed;
+
+ private:
+  typedef std::list<Permission*> PermissionList;
+  typedef std::list<Channel*> ChannelList;
+
+  void HandleAllocateRequest(const TurnMessage* msg);
+  void HandleRefreshRequest(const TurnMessage* msg);
+  void HandleSendIndication(const TurnMessage* msg);
+  void HandleCreatePermissionRequest(const TurnMessage* msg);
+  void HandleChannelBindRequest(const TurnMessage* msg);
+
+  void OnExternalPacket(rtc::AsyncPacketSocket* socket,
+                        const char* data, size_t size,
+                        const rtc::SocketAddress& addr,
+                        const rtc::PacketTime& packet_time);
+
+  static int ComputeLifetime(const TurnMessage* msg);
+  bool HasPermission(const rtc::IPAddress& addr);
+  void AddPermission(const rtc::IPAddress& addr);
+  Permission* FindPermission(const rtc::IPAddress& addr) const;
+  Channel* FindChannel(int channel_id) const;
+  Channel* FindChannel(const rtc::SocketAddress& addr) const;
+
+  void SendResponse(TurnMessage* msg);
+  void SendBadRequestResponse(const TurnMessage* req);
+  void SendErrorResponse(const TurnMessage* req, int code,
+                         const std::string& reason);
+  void SendExternal(const void* data, size_t size,
+                    const rtc::SocketAddress& peer);
+
+  void OnPermissionDestroyed(Permission* perm);
+  void OnChannelDestroyed(Channel* channel);
+  virtual void OnMessage(rtc::Message* msg);
+
+  TurnServer* server_;
+  rtc::Thread* thread_;
+  Connection conn_;
+  rtc::scoped_ptr<rtc::AsyncPacketSocket> external_socket_;
+  std::string key_;
+  std::string transaction_id_;
+  std::string username_;
+  std::string last_nonce_;
+  PermissionList perms_;
+  ChannelList channels_;
+};
+
+// Encapsulates a TURN permission.
+// The object is created when a create permission request is received by an
+// allocation, and self-deletes when its lifetime timer expires.
+class TurnServer::Permission : public rtc::MessageHandler {
+ public:
+  Permission(rtc::Thread* thread, const rtc::IPAddress& peer);
+  ~Permission();
+
+  const rtc::IPAddress& peer() const { return peer_; }
+  void Refresh();
+
+  sigslot::signal1<Permission*> SignalDestroyed;
+
+ private:
+  virtual void OnMessage(rtc::Message* msg);
+
+  rtc::Thread* thread_;
+  rtc::IPAddress peer_;
+};
+
+// Encapsulates a TURN channel binding.
+// The object is created when a channel bind request is received by an
+// allocation, and self-deletes when its lifetime timer expires.
+class TurnServer::Channel : public rtc::MessageHandler {
+ public:
+  Channel(rtc::Thread* thread, int id,
+                     const rtc::SocketAddress& peer);
+  ~Channel();
+
+  int id() const { return id_; }
+  const rtc::SocketAddress& peer() const { return peer_; }
+  void Refresh();
+
+  sigslot::signal1<Channel*> SignalDestroyed;
+
+ private:
+  virtual void OnMessage(rtc::Message* msg);
+
+  rtc::Thread* thread_;
+  int id_;
+  rtc::SocketAddress peer_;
+};
+
+static bool InitResponse(const StunMessage* req, StunMessage* resp) {
+  int resp_type = (req) ? GetStunSuccessResponseType(req->type()) : -1;
+  if (resp_type == -1)
+    return false;
+  resp->SetType(resp_type);
+  resp->SetTransactionID(req->transaction_id());
+  return true;
+}
+
+static bool InitErrorResponse(const StunMessage* req, int code,
+                              const std::string& reason, StunMessage* resp) {
+  int resp_type = (req) ? GetStunErrorResponseType(req->type()) : -1;
+  if (resp_type == -1)
+    return false;
+  resp->SetType(resp_type);
+  resp->SetTransactionID(req->transaction_id());
+  VERIFY(resp->AddAttribute(new cricket::StunErrorCodeAttribute(
+      STUN_ATTR_ERROR_CODE, code, reason)));
+  return true;
+}
+
+TurnServer::TurnServer(rtc::Thread* thread)
+    : thread_(thread),
+      nonce_key_(rtc::CreateRandomString(kNonceKeySize)),
+      auth_hook_(NULL),
+      redirect_hook_(NULL),
+      enable_otu_nonce_(false) {
+}
+
+TurnServer::~TurnServer() {
+  for (AllocationMap::iterator it = allocations_.begin();
+       it != allocations_.end(); ++it) {
+    delete it->second;
+  }
+
+  for (InternalSocketMap::iterator it = server_sockets_.begin();
+       it != server_sockets_.end(); ++it) {
+    rtc::AsyncPacketSocket* socket = it->first;
+    delete socket;
+  }
+
+  for (ServerSocketMap::iterator it = server_listen_sockets_.begin();
+       it != server_listen_sockets_.end(); ++it) {
+    rtc::AsyncSocket* socket = it->first;
+    delete socket;
+  }
+}
+
+void TurnServer::AddInternalSocket(rtc::AsyncPacketSocket* socket,
+                                   ProtocolType proto) {
+  ASSERT(server_sockets_.end() == server_sockets_.find(socket));
+  server_sockets_[socket] = proto;
+  socket->SignalReadPacket.connect(this, &TurnServer::OnInternalPacket);
+}
+
+void TurnServer::AddInternalServerSocket(rtc::AsyncSocket* socket,
+                                         ProtocolType proto) {
+  ASSERT(server_listen_sockets_.end() ==
+      server_listen_sockets_.find(socket));
+  server_listen_sockets_[socket] = proto;
+  socket->SignalReadEvent.connect(this, &TurnServer::OnNewInternalConnection);
+}
+
+void TurnServer::SetExternalSocketFactory(
+    rtc::PacketSocketFactory* factory,
+    const rtc::SocketAddress& external_addr) {
+  external_socket_factory_.reset(factory);
+  external_addr_ = external_addr;
+}
+
+void TurnServer::OnNewInternalConnection(rtc::AsyncSocket* socket) {
+  ASSERT(server_listen_sockets_.find(socket) != server_listen_sockets_.end());
+  AcceptConnection(socket);
+}
+
+void TurnServer::AcceptConnection(rtc::AsyncSocket* server_socket) {
+  // Check if someone is trying to connect to us.
+  rtc::SocketAddress accept_addr;
+  rtc::AsyncSocket* accepted_socket = server_socket->Accept(&accept_addr);
+  if (accepted_socket != NULL) {
+    ProtocolType proto = server_listen_sockets_[server_socket];
+    cricket::AsyncStunTCPSocket* tcp_socket =
+        new cricket::AsyncStunTCPSocket(accepted_socket, false);
+
+    tcp_socket->SignalClose.connect(this, &TurnServer::OnInternalSocketClose);
+    // Finally add the socket so it can start communicating with the client.
+    AddInternalSocket(tcp_socket, proto);
+  }
+}
+
+void TurnServer::OnInternalSocketClose(rtc::AsyncPacketSocket* socket,
+                                       int err) {
+  DestroyInternalSocket(socket);
+}
+
+void TurnServer::OnInternalPacket(rtc::AsyncPacketSocket* socket,
+                                  const char* data, size_t size,
+                                  const rtc::SocketAddress& addr,
+                                  const rtc::PacketTime& packet_time) {
+  // Fail if the packet is too small to even contain a channel header.
+  if (size < TURN_CHANNEL_HEADER_SIZE) {
+   return;
+  }
+  InternalSocketMap::iterator iter = server_sockets_.find(socket);
+  ASSERT(iter != server_sockets_.end());
+  Connection conn(addr, iter->second, socket);
+  uint16 msg_type = rtc::GetBE16(data);
+  if (!IsTurnChannelData(msg_type)) {
+    // This is a STUN message.
+    HandleStunMessage(&conn, data, size);
+  } else {
+    // This is a channel message; let the allocation handle it.
+    Allocation* allocation = FindAllocation(&conn);
+    if (allocation) {
+      allocation->HandleChannelData(data, size);
+    }
+  }
+}
+
+void TurnServer::HandleStunMessage(Connection* conn, const char* data,
+                                   size_t size) {
+  TurnMessage msg;
+  rtc::ByteBuffer buf(data, size);
+  if (!msg.Read(&buf) || (buf.Length() > 0)) {
+    LOG(LS_WARNING) << "Received invalid STUN message";
+    return;
+  }
+
+  // If it's a STUN binding request, handle that specially.
+  if (msg.type() == STUN_BINDING_REQUEST) {
+    HandleBindingRequest(conn, &msg);
+    return;
+  }
+
+  if (redirect_hook_ != NULL && msg.type() == STUN_ALLOCATE_REQUEST) {
+    rtc::SocketAddress address;
+    if (redirect_hook_->ShouldRedirect(conn->src(), &address)) {
+      SendErrorResponseWithAlternateServer(
+          conn, &msg, address);
+      return;
+    }
+  }
+
+  // Look up the key that we'll use to validate the M-I. If we have an
+  // existing allocation, the key will already be cached.
+  Allocation* allocation = FindAllocation(conn);
+  std::string key;
+  if (!allocation) {
+    GetKey(&msg, &key);
+  } else {
+    key = allocation->key();
+  }
+
+  // Ensure the message is authorized; only needed for requests.
+  if (IsStunRequestType(msg.type())) {
+    if (!CheckAuthorization(conn, &msg, data, size, key)) {
+      return;
+    }
+  }
+
+  if (!allocation && msg.type() == STUN_ALLOCATE_REQUEST) {
+    HandleAllocateRequest(conn, &msg, key);
+  } else if (allocation &&
+             (msg.type() != STUN_ALLOCATE_REQUEST ||
+              msg.transaction_id() == allocation->transaction_id())) {
+    // This is a non-allocate request, or a retransmit of an allocate.
+    // Check that the username matches the previous username used.
+    if (IsStunRequestType(msg.type()) &&
+        msg.GetByteString(STUN_ATTR_USERNAME)->GetString() !=
+            allocation->username()) {
+      SendErrorResponse(conn, &msg, STUN_ERROR_WRONG_CREDENTIALS,
+                        STUN_ERROR_REASON_WRONG_CREDENTIALS);
+      return;
+    }
+    allocation->HandleTurnMessage(&msg);
+  } else {
+    // Allocation mismatch.
+    SendErrorResponse(conn, &msg, STUN_ERROR_ALLOCATION_MISMATCH,
+                      STUN_ERROR_REASON_ALLOCATION_MISMATCH);
+  }
+}
+
+bool TurnServer::GetKey(const StunMessage* msg, std::string* key) {
+  const StunByteStringAttribute* username_attr =
+      msg->GetByteString(STUN_ATTR_USERNAME);
+  if (!username_attr) {
+    return false;
+  }
+
+  std::string username = username_attr->GetString();
+  return (auth_hook_ != NULL && auth_hook_->GetKey(username, realm_, key));
+}
+
+bool TurnServer::CheckAuthorization(Connection* conn,
+                                    const StunMessage* msg,
+                                    const char* data, size_t size,
+                                    const std::string& key) {
+  // RFC 5389, 10.2.2.
+  ASSERT(IsStunRequestType(msg->type()));
+  const StunByteStringAttribute* mi_attr =
+      msg->GetByteString(STUN_ATTR_MESSAGE_INTEGRITY);
+  const StunByteStringAttribute* username_attr =
+      msg->GetByteString(STUN_ATTR_USERNAME);
+  const StunByteStringAttribute* realm_attr =
+      msg->GetByteString(STUN_ATTR_REALM);
+  const StunByteStringAttribute* nonce_attr =
+      msg->GetByteString(STUN_ATTR_NONCE);
+
+  // Fail if no M-I.
+  if (!mi_attr) {
+    SendErrorResponseWithRealmAndNonce(conn, msg, STUN_ERROR_UNAUTHORIZED,
+                                       STUN_ERROR_REASON_UNAUTHORIZED);
+    return false;
+  }
+
+  // Fail if there is M-I but no username, nonce, or realm.
+  if (!username_attr || !realm_attr || !nonce_attr) {
+    SendErrorResponse(conn, msg, STUN_ERROR_BAD_REQUEST,
+                      STUN_ERROR_REASON_BAD_REQUEST);
+    return false;
+  }
+
+  // Fail if bad nonce.
+  if (!ValidateNonce(nonce_attr->GetString())) {
+    SendErrorResponseWithRealmAndNonce(conn, msg, STUN_ERROR_STALE_NONCE,
+                                       STUN_ERROR_REASON_STALE_NONCE);
+    return false;
+  }
+
+  // Fail if bad username or M-I.
+  // We need |data| and |size| for the call to ValidateMessageIntegrity.
+  if (key.empty() || !StunMessage::ValidateMessageIntegrity(data, size, key)) {
+    SendErrorResponseWithRealmAndNonce(conn, msg, STUN_ERROR_UNAUTHORIZED,
+                                       STUN_ERROR_REASON_UNAUTHORIZED);
+    return false;
+  }
+
+  // Fail if one-time-use nonce feature is enabled.
+  Allocation* allocation = FindAllocation(conn);
+  if (enable_otu_nonce_ && allocation &&
+      allocation->last_nonce() == nonce_attr->GetString()) {
+    SendErrorResponseWithRealmAndNonce(conn, msg, STUN_ERROR_STALE_NONCE,
+                                       STUN_ERROR_REASON_STALE_NONCE);
+    return false;
+  }
+
+  if (allocation) {
+    allocation->set_last_nonce(nonce_attr->GetString());
+  }
+  // Success.
+  return true;
+}
+
+void TurnServer::HandleBindingRequest(Connection* conn,
+                                      const StunMessage* req) {
+  StunMessage response;
+  InitResponse(req, &response);
+
+  // Tell the user the address that we received their request from.
+  StunAddressAttribute* mapped_addr_attr;
+  mapped_addr_attr = new StunXorAddressAttribute(
+      STUN_ATTR_XOR_MAPPED_ADDRESS, conn->src());
+  VERIFY(response.AddAttribute(mapped_addr_attr));
+
+  SendStun(conn, &response);
+}
+
+void TurnServer::HandleAllocateRequest(Connection* conn,
+                                       const TurnMessage* msg,
+                                       const std::string& key) {
+  // Check the parameters in the request.
+  const StunUInt32Attribute* transport_attr =
+      msg->GetUInt32(STUN_ATTR_REQUESTED_TRANSPORT);
+  if (!transport_attr) {
+    SendErrorResponse(conn, msg, STUN_ERROR_BAD_REQUEST,
+                      STUN_ERROR_REASON_BAD_REQUEST);
+    return;
+  }
+
+  // Only UDP is supported right now.
+  int proto = transport_attr->value() >> 24;
+  if (proto != IPPROTO_UDP) {
+    SendErrorResponse(conn, msg, STUN_ERROR_UNSUPPORTED_PROTOCOL,
+                      STUN_ERROR_REASON_UNSUPPORTED_PROTOCOL);
+    return;
+  }
+
+  // Create the allocation and let it send the success response.
+  // If the actual socket allocation fails, send an internal error.
+  Allocation* alloc = CreateAllocation(conn, proto, key);
+  if (alloc) {
+    alloc->HandleTurnMessage(msg);
+  } else {
+    SendErrorResponse(conn, msg, STUN_ERROR_SERVER_ERROR,
+                      "Failed to allocate socket");
+  }
+}
+
+std::string TurnServer::GenerateNonce() const {
+  // Generate a nonce of the form hex(now + HMAC-MD5(nonce_key_, now))
+  uint32 now = rtc::Time();
+  std::string input(reinterpret_cast<const char*>(&now), sizeof(now));
+  std::string nonce = rtc::hex_encode(input.c_str(), input.size());
+  nonce += rtc::ComputeHmac(rtc::DIGEST_MD5, nonce_key_, input);
+  ASSERT(nonce.size() == kNonceSize);
+  return nonce;
+}
+
+bool TurnServer::ValidateNonce(const std::string& nonce) const {
+  // Check the size.
+  if (nonce.size() != kNonceSize) {
+    return false;
+  }
+
+  // Decode the timestamp.
+  uint32 then;
+  char* p = reinterpret_cast<char*>(&then);
+  size_t len = rtc::hex_decode(p, sizeof(then),
+      nonce.substr(0, sizeof(then) * 2));
+  if (len != sizeof(then)) {
+    return false;
+  }
+
+  // Verify the HMAC.
+  if (nonce.substr(sizeof(then) * 2) != rtc::ComputeHmac(
+      rtc::DIGEST_MD5, nonce_key_, std::string(p, sizeof(then)))) {
+    return false;
+  }
+
+  // Validate the timestamp.
+  return rtc::TimeSince(then) < kNonceTimeout;
+}
+
+TurnServer::Allocation* TurnServer::FindAllocation(Connection* conn) {
+  AllocationMap::const_iterator it = allocations_.find(*conn);
+  return (it != allocations_.end()) ? it->second : NULL;
+}
+
+TurnServer::Allocation* TurnServer::CreateAllocation(Connection* conn,
+                                                     int proto,
+                                                     const std::string& key) {
+  rtc::AsyncPacketSocket* external_socket = (external_socket_factory_) ?
+      external_socket_factory_->CreateUdpSocket(external_addr_, 0, 0) : NULL;
+  if (!external_socket) {
+    return NULL;
+  }
+
+  // The Allocation takes ownership of the socket.
+  Allocation* allocation = new Allocation(this,
+      thread_, *conn, external_socket, key);
+  allocation->SignalDestroyed.connect(this, &TurnServer::OnAllocationDestroyed);
+  allocations_[*conn] = allocation;
+  return allocation;
+}
+
+void TurnServer::SendErrorResponse(Connection* conn,
+                                   const StunMessage* req,
+                                   int code, const std::string& reason) {
+  TurnMessage resp;
+  InitErrorResponse(req, code, reason, &resp);
+  LOG(LS_INFO) << "Sending error response, type=" << resp.type()
+               << ", code=" << code << ", reason=" << reason;
+  SendStun(conn, &resp);
+}
+
+void TurnServer::SendErrorResponseWithRealmAndNonce(
+    Connection* conn, const StunMessage* msg,
+    int code, const std::string& reason) {
+  TurnMessage resp;
+  InitErrorResponse(msg, code, reason, &resp);
+  VERIFY(resp.AddAttribute(new StunByteStringAttribute(
+      STUN_ATTR_NONCE, GenerateNonce())));
+  VERIFY(resp.AddAttribute(new StunByteStringAttribute(
+      STUN_ATTR_REALM, realm_)));
+  SendStun(conn, &resp);
+}
+
+void TurnServer::SendErrorResponseWithAlternateServer(
+    Connection* conn, const StunMessage* msg,
+    const rtc::SocketAddress& addr) {
+  TurnMessage resp;
+  InitErrorResponse(msg, STUN_ERROR_TRY_ALTERNATE,
+                    STUN_ERROR_REASON_TRY_ALTERNATE_SERVER, &resp);
+  VERIFY(resp.AddAttribute(new StunAddressAttribute(
+      STUN_ATTR_ALTERNATE_SERVER, addr)));
+  SendStun(conn, &resp);
+}
+
+void TurnServer::SendStun(Connection* conn, StunMessage* msg) {
+  rtc::ByteBuffer buf;
+  // Add a SOFTWARE attribute if one is set.
+  if (!software_.empty()) {
+    VERIFY(msg->AddAttribute(
+        new StunByteStringAttribute(STUN_ATTR_SOFTWARE, software_)));
+  }
+  msg->Write(&buf);
+  Send(conn, buf);
+}
+
+void TurnServer::Send(Connection* conn,
+                      const rtc::ByteBuffer& buf) {
+  rtc::PacketOptions options;
+  conn->socket()->SendTo(buf.Data(), buf.Length(), conn->src(), options);
+}
+
+void TurnServer::OnAllocationDestroyed(Allocation* allocation) {
+  // Removing the internal socket if the connection is not udp.
+  rtc::AsyncPacketSocket* socket = allocation->conn()->socket();
+  InternalSocketMap::iterator iter = server_sockets_.find(socket);
+  ASSERT(iter != server_sockets_.end());
+  // Skip if the socket serving this allocation is UDP, as this will be shared
+  // by all allocations.
+  if (iter->second != cricket::PROTO_UDP) {
+    DestroyInternalSocket(socket);
+  }
+
+  AllocationMap::iterator it = allocations_.find(*(allocation->conn()));
+  if (it != allocations_.end())
+    allocations_.erase(it);
+}
+
+void TurnServer::DestroyInternalSocket(rtc::AsyncPacketSocket* socket) {
+  InternalSocketMap::iterator iter = server_sockets_.find(socket);
+  if (iter != server_sockets_.end()) {
+    rtc::AsyncPacketSocket* socket = iter->first;
+    // We must destroy the socket async to avoid invalidating the sigslot
+    // callback list iterator inside a sigslot callback.
+    rtc::Thread::Current()->Dispose(socket);
+    server_sockets_.erase(iter);
+  }
+}
+
+TurnServer::Connection::Connection(const rtc::SocketAddress& src,
+                                   ProtocolType proto,
+                                   rtc::AsyncPacketSocket* socket)
+    : src_(src),
+      dst_(socket->GetRemoteAddress()),
+      proto_(proto),
+      socket_(socket) {
+}
+
+bool TurnServer::Connection::operator==(const Connection& c) const {
+  return src_ == c.src_ && dst_ == c.dst_ && proto_ == c.proto_;
+}
+
+bool TurnServer::Connection::operator<(const Connection& c) const {
+  return src_ < c.src_ || dst_ < c.dst_ || proto_ < c.proto_;
+}
+
+std::string TurnServer::Connection::ToString() const {
+  const char* const kProtos[] = {
+      "unknown", "udp", "tcp", "ssltcp"
+  };
+  std::ostringstream ost;
+  ost << src_.ToString() << "-" << dst_.ToString() << ":"<< kProtos[proto_];
+  return ost.str();
+}
+
+TurnServer::Allocation::Allocation(TurnServer* server,
+                                   rtc::Thread* thread,
+                                   const Connection& conn,
+                                   rtc::AsyncPacketSocket* socket,
+                                   const std::string& key)
+    : server_(server),
+      thread_(thread),
+      conn_(conn),
+      external_socket_(socket),
+      key_(key) {
+  external_socket_->SignalReadPacket.connect(
+      this, &TurnServer::Allocation::OnExternalPacket);
+}
+
+TurnServer::Allocation::~Allocation() {
+  for (ChannelList::iterator it = channels_.begin();
+       it != channels_.end(); ++it) {
+    delete *it;
+  }
+  for (PermissionList::iterator it = perms_.begin();
+       it != perms_.end(); ++it) {
+    delete *it;
+  }
+  thread_->Clear(this, MSG_ALLOCATION_TIMEOUT);
+  LOG_J(LS_INFO, this) << "Allocation destroyed";
+}
+
+std::string TurnServer::Allocation::ToString() const {
+  std::ostringstream ost;
+  ost << "Alloc[" << conn_.ToString() << "]";
+  return ost.str();
+}
+
+void TurnServer::Allocation::HandleTurnMessage(const TurnMessage* msg) {
+  ASSERT(msg != NULL);
+  switch (msg->type()) {
+    case STUN_ALLOCATE_REQUEST:
+      HandleAllocateRequest(msg);
+      break;
+    case TURN_REFRESH_REQUEST:
+      HandleRefreshRequest(msg);
+      break;
+    case TURN_SEND_INDICATION:
+      HandleSendIndication(msg);
+      break;
+    case TURN_CREATE_PERMISSION_REQUEST:
+      HandleCreatePermissionRequest(msg);
+      break;
+    case TURN_CHANNEL_BIND_REQUEST:
+      HandleChannelBindRequest(msg);
+      break;
+    default:
+      // Not sure what to do with this, just eat it.
+      LOG_J(LS_WARNING, this) << "Invalid TURN message type received: "
+                              << msg->type();
+  }
+}
+
+void TurnServer::Allocation::HandleAllocateRequest(const TurnMessage* msg) {
+  // Copy the important info from the allocate request.
+  transaction_id_ = msg->transaction_id();
+  const StunByteStringAttribute* username_attr =
+      msg->GetByteString(STUN_ATTR_USERNAME);
+  ASSERT(username_attr != NULL);
+  username_ = username_attr->GetString();
+
+  // Figure out the lifetime and start the allocation timer.
+  int lifetime_secs = ComputeLifetime(msg);
+  thread_->PostDelayed(lifetime_secs * 1000, this, MSG_ALLOCATION_TIMEOUT);
+
+  LOG_J(LS_INFO, this) << "Created allocation, lifetime=" << lifetime_secs;
+
+  // We've already validated all the important bits; just send a response here.
+  TurnMessage response;
+  InitResponse(msg, &response);
+
+  StunAddressAttribute* mapped_addr_attr =
+      new StunXorAddressAttribute(STUN_ATTR_XOR_MAPPED_ADDRESS, conn_.src());
+  StunAddressAttribute* relayed_addr_attr =
+      new StunXorAddressAttribute(STUN_ATTR_XOR_RELAYED_ADDRESS,
+          external_socket_->GetLocalAddress());
+  StunUInt32Attribute* lifetime_attr =
+      new StunUInt32Attribute(STUN_ATTR_LIFETIME, lifetime_secs);
+  VERIFY(response.AddAttribute(mapped_addr_attr));
+  VERIFY(response.AddAttribute(relayed_addr_attr));
+  VERIFY(response.AddAttribute(lifetime_attr));
+
+  SendResponse(&response);
+}
+
+void TurnServer::Allocation::HandleRefreshRequest(const TurnMessage* msg) {
+  // Figure out the new lifetime.
+  int lifetime_secs = ComputeLifetime(msg);
+
+  // Reset the expiration timer.
+  thread_->Clear(this, MSG_ALLOCATION_TIMEOUT);
+  thread_->PostDelayed(lifetime_secs * 1000, this, MSG_ALLOCATION_TIMEOUT);
+
+  LOG_J(LS_INFO, this) << "Refreshed allocation, lifetime=" << lifetime_secs;
+
+  // Send a success response with a LIFETIME attribute.
+  TurnMessage response;
+  InitResponse(msg, &response);
+
+  StunUInt32Attribute* lifetime_attr =
+      new StunUInt32Attribute(STUN_ATTR_LIFETIME, lifetime_secs);
+  VERIFY(response.AddAttribute(lifetime_attr));
+
+  SendResponse(&response);
+}
+
+void TurnServer::Allocation::HandleSendIndication(const TurnMessage* msg) {
+  // Check mandatory attributes.
+  const StunByteStringAttribute* data_attr = msg->GetByteString(STUN_ATTR_DATA);
+  const StunAddressAttribute* peer_attr =
+      msg->GetAddress(STUN_ATTR_XOR_PEER_ADDRESS);
+  if (!data_attr || !peer_attr) {
+    LOG_J(LS_WARNING, this) << "Received invalid send indication";
+    return;
+  }
+
+  // If a permission exists, send the data on to the peer.
+  if (HasPermission(peer_attr->GetAddress().ipaddr())) {
+    SendExternal(data_attr->bytes(), data_attr->length(),
+                 peer_attr->GetAddress());
+  } else {
+    LOG_J(LS_WARNING, this) << "Received send indication without permission"
+                            << "peer=" << peer_attr->GetAddress();
+  }
+}
+
+void TurnServer::Allocation::HandleCreatePermissionRequest(
+    const TurnMessage* msg) {
+  // Check mandatory attributes.
+  const StunAddressAttribute* peer_attr =
+      msg->GetAddress(STUN_ATTR_XOR_PEER_ADDRESS);
+  if (!peer_attr) {
+    SendBadRequestResponse(msg);
+    return;
+  }
+
+  // Add this permission.
+  AddPermission(peer_attr->GetAddress().ipaddr());
+
+  LOG_J(LS_INFO, this) << "Created permission, peer="
+                       << peer_attr->GetAddress();
+
+  // Send a success response.
+  TurnMessage response;
+  InitResponse(msg, &response);
+  SendResponse(&response);
+}
+
+void TurnServer::Allocation::HandleChannelBindRequest(const TurnMessage* msg) {
+  // Check mandatory attributes.
+  const StunUInt32Attribute* channel_attr =
+      msg->GetUInt32(STUN_ATTR_CHANNEL_NUMBER);
+  const StunAddressAttribute* peer_attr =
+      msg->GetAddress(STUN_ATTR_XOR_PEER_ADDRESS);
+  if (!channel_attr || !peer_attr) {
+    SendBadRequestResponse(msg);
+    return;
+  }
+
+  // Check that channel id is valid.
+  int channel_id = channel_attr->value() >> 16;
+  if (channel_id < kMinChannelNumber || channel_id > kMaxChannelNumber) {
+    SendBadRequestResponse(msg);
+    return;
+  }
+
+  // Check that this channel id isn't bound to another transport address, and
+  // that this transport address isn't bound to another channel id.
+  Channel* channel1 = FindChannel(channel_id);
+  Channel* channel2 = FindChannel(peer_attr->GetAddress());
+  if (channel1 != channel2) {
+    SendBadRequestResponse(msg);
+    return;
+  }
+
+  // Add or refresh this channel.
+  if (!channel1) {
+    channel1 = new Channel(thread_, channel_id, peer_attr->GetAddress());
+    channel1->SignalDestroyed.connect(this,
+        &TurnServer::Allocation::OnChannelDestroyed);
+    channels_.push_back(channel1);
+  } else {
+    channel1->Refresh();
+  }
+
+  // Channel binds also refresh permissions.
+  AddPermission(peer_attr->GetAddress().ipaddr());
+
+  LOG_J(LS_INFO, this) << "Bound channel, id=" << channel_id
+                       << ", peer=" << peer_attr->GetAddress();
+
+  // Send a success response.
+  TurnMessage response;
+  InitResponse(msg, &response);
+  SendResponse(&response);
+}
+
+void TurnServer::Allocation::HandleChannelData(const char* data, size_t size) {
+  // Extract the channel number from the data.
+  uint16 channel_id = rtc::GetBE16(data);
+  Channel* channel = FindChannel(channel_id);
+  if (channel) {
+    // Send the data to the peer address.
+    SendExternal(data + TURN_CHANNEL_HEADER_SIZE,
+                 size - TURN_CHANNEL_HEADER_SIZE, channel->peer());
+  } else {
+    LOG_J(LS_WARNING, this) << "Received channel data for invalid channel, id="
+                            << channel_id;
+  }
+}
+
+void TurnServer::Allocation::OnExternalPacket(
+    rtc::AsyncPacketSocket* socket,
+    const char* data, size_t size,
+    const rtc::SocketAddress& addr,
+    const rtc::PacketTime& packet_time) {
+  ASSERT(external_socket_.get() == socket);
+  Channel* channel = FindChannel(addr);
+  if (channel) {
+    // There is a channel bound to this address. Send as a channel message.
+    rtc::ByteBuffer buf;
+    buf.WriteUInt16(channel->id());
+    buf.WriteUInt16(static_cast<uint16>(size));
+    buf.WriteBytes(data, size);
+    server_->Send(&conn_, buf);
+  } else if (HasPermission(addr.ipaddr())) {
+    // No channel, but a permission exists. Send as a data indication.
+    TurnMessage msg;
+    msg.SetType(TURN_DATA_INDICATION);
+    msg.SetTransactionID(
+        rtc::CreateRandomString(kStunTransactionIdLength));
+    VERIFY(msg.AddAttribute(new StunXorAddressAttribute(
+        STUN_ATTR_XOR_PEER_ADDRESS, addr)));
+    VERIFY(msg.AddAttribute(new StunByteStringAttribute(
+        STUN_ATTR_DATA, data, size)));
+    server_->SendStun(&conn_, &msg);
+  } else {
+    LOG_J(LS_WARNING, this) << "Received external packet without permission, "
+                            << "peer=" << addr;
+  }
+}
+
+int TurnServer::Allocation::ComputeLifetime(const TurnMessage* msg) {
+  // Return the smaller of our default lifetime and the requested lifetime.
+  uint32 lifetime = kDefaultAllocationTimeout / 1000;  // convert to seconds
+  const StunUInt32Attribute* lifetime_attr = msg->GetUInt32(STUN_ATTR_LIFETIME);
+  if (lifetime_attr && lifetime_attr->value() < lifetime) {
+    lifetime = lifetime_attr->value();
+  }
+  return lifetime;
+}
+
+bool TurnServer::Allocation::HasPermission(const rtc::IPAddress& addr) {
+  return (FindPermission(addr) != NULL);
+}
+
+void TurnServer::Allocation::AddPermission(const rtc::IPAddress& addr) {
+  Permission* perm = FindPermission(addr);
+  if (!perm) {
+    perm = new Permission(thread_, addr);
+    perm->SignalDestroyed.connect(
+        this, &TurnServer::Allocation::OnPermissionDestroyed);
+    perms_.push_back(perm);
+  } else {
+    perm->Refresh();
+  }
+}
+
+TurnServer::Permission* TurnServer::Allocation::FindPermission(
+    const rtc::IPAddress& addr) const {
+  for (PermissionList::const_iterator it = perms_.begin();
+       it != perms_.end(); ++it) {
+    if ((*it)->peer() == addr)
+      return *it;
+  }
+  return NULL;
+}
+
+TurnServer::Channel* TurnServer::Allocation::FindChannel(int channel_id) const {
+  for (ChannelList::const_iterator it = channels_.begin();
+       it != channels_.end(); ++it) {
+    if ((*it)->id() == channel_id)
+      return *it;
+  }
+  return NULL;
+}
+
+TurnServer::Channel* TurnServer::Allocation::FindChannel(
+    const rtc::SocketAddress& addr) const {
+  for (ChannelList::const_iterator it = channels_.begin();
+       it != channels_.end(); ++it) {
+    if ((*it)->peer() == addr)
+      return *it;
+  }
+  return NULL;
+}
+
+void TurnServer::Allocation::SendResponse(TurnMessage* msg) {
+  // Success responses always have M-I.
+  msg->AddMessageIntegrity(key_);
+  server_->SendStun(&conn_, msg);
+}
+
+void TurnServer::Allocation::SendBadRequestResponse(const TurnMessage* req) {
+  SendErrorResponse(req, STUN_ERROR_BAD_REQUEST, STUN_ERROR_REASON_BAD_REQUEST);
+}
+
+void TurnServer::Allocation::SendErrorResponse(const TurnMessage* req, int code,
+                                       const std::string& reason) {
+  server_->SendErrorResponse(&conn_, req, code, reason);
+}
+
+void TurnServer::Allocation::SendExternal(const void* data, size_t size,
+                                  const rtc::SocketAddress& peer) {
+  rtc::PacketOptions options;
+  external_socket_->SendTo(data, size, peer, options);
+}
+
+void TurnServer::Allocation::OnMessage(rtc::Message* msg) {
+  ASSERT(msg->message_id == MSG_ALLOCATION_TIMEOUT);
+  SignalDestroyed(this);
+  delete this;
+}
+
+void TurnServer::Allocation::OnPermissionDestroyed(Permission* perm) {
+  PermissionList::iterator it = std::find(perms_.begin(), perms_.end(), perm);
+  ASSERT(it != perms_.end());
+  perms_.erase(it);
+}
+
+void TurnServer::Allocation::OnChannelDestroyed(Channel* channel) {
+  ChannelList::iterator it =
+      std::find(channels_.begin(), channels_.end(), channel);
+  ASSERT(it != channels_.end());
+  channels_.erase(it);
+}
+
+TurnServer::Permission::Permission(rtc::Thread* thread,
+                                   const rtc::IPAddress& peer)
+    : thread_(thread), peer_(peer) {
+  Refresh();
+}
+
+TurnServer::Permission::~Permission() {
+  thread_->Clear(this, MSG_ALLOCATION_TIMEOUT);
+}
+
+void TurnServer::Permission::Refresh() {
+  thread_->Clear(this, MSG_ALLOCATION_TIMEOUT);
+  thread_->PostDelayed(kPermissionTimeout, this, MSG_ALLOCATION_TIMEOUT);
+}
+
+void TurnServer::Permission::OnMessage(rtc::Message* msg) {
+  ASSERT(msg->message_id == MSG_ALLOCATION_TIMEOUT);
+  SignalDestroyed(this);
+  delete this;
+}
+
+TurnServer::Channel::Channel(rtc::Thread* thread, int id,
+                             const rtc::SocketAddress& peer)
+    : thread_(thread), id_(id), peer_(peer) {
+  Refresh();
+}
+
+TurnServer::Channel::~Channel() {
+  thread_->Clear(this, MSG_ALLOCATION_TIMEOUT);
+}
+
+void TurnServer::Channel::Refresh() {
+  thread_->Clear(this, MSG_ALLOCATION_TIMEOUT);
+  thread_->PostDelayed(kChannelTimeout, this, MSG_ALLOCATION_TIMEOUT);
+}
+
+void TurnServer::Channel::OnMessage(rtc::Message* msg) {
+  ASSERT(msg->message_id == MSG_ALLOCATION_TIMEOUT);
+  SignalDestroyed(this);
+  delete this;
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/base/turnserver.h b/webrtc/p2p/base/turnserver.h
new file mode 100644
index 0000000..670b618
--- /dev/null
+++ b/webrtc/p2p/base/turnserver.h
@@ -0,0 +1,190 @@
+/*
+ *  Copyright 2012 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_TURNSERVER_H_
+#define WEBRTC_P2P_BASE_TURNSERVER_H_
+
+#include <list>
+#include <map>
+#include <set>
+#include <string>
+
+#include "webrtc/p2p/base/portinterface.h"
+#include "webrtc/base/asyncpacketsocket.h"
+#include "webrtc/base/messagequeue.h"
+#include "webrtc/base/sigslot.h"
+#include "webrtc/base/socketaddress.h"
+
+namespace rtc {
+class ByteBuffer;
+class PacketSocketFactory;
+class Thread;
+}
+
+namespace cricket {
+
+class StunMessage;
+class TurnMessage;
+
+// The default server port for TURN, as specified in RFC5766.
+const int TURN_SERVER_PORT = 3478;
+
+// An interface through which the MD5 credential hash can be retrieved.
+class TurnAuthInterface {
+ public:
+  // Gets HA1 for the specified user and realm.
+  // HA1 = MD5(A1) = MD5(username:realm:password).
+  // Return true if the given username and realm are valid, or false if not.
+  virtual bool GetKey(const std::string& username, const std::string& realm,
+                      std::string* key) = 0;
+};
+
+// An interface enables Turn Server to control redirection behavior.
+class TurnRedirectInterface {
+ public:
+  virtual bool ShouldRedirect(const rtc::SocketAddress& address,
+                              rtc::SocketAddress* out) = 0;
+  virtual ~TurnRedirectInterface() {}
+};
+
+// The core TURN server class. Give it a socket to listen on via
+// AddInternalServerSocket, and a factory to create external sockets via
+// SetExternalSocketFactory, and it's ready to go.
+// Not yet wired up: TCP support.
+class TurnServer : public sigslot::has_slots<> {
+ public:
+  explicit TurnServer(rtc::Thread* thread);
+  ~TurnServer();
+
+  // Gets/sets the realm value to use for the server.
+  const std::string& realm() const { return realm_; }
+  void set_realm(const std::string& realm) { realm_ = realm; }
+
+  // Gets/sets the value for the SOFTWARE attribute for TURN messages.
+  const std::string& software() const { return software_; }
+  void set_software(const std::string& software) { software_ = software; }
+
+  // Sets the authentication callback; does not take ownership.
+  void set_auth_hook(TurnAuthInterface* auth_hook) { auth_hook_ = auth_hook; }
+
+  void set_redirect_hook(TurnRedirectInterface* redirect_hook) {
+    redirect_hook_ = redirect_hook;
+  }
+
+  void set_enable_otu_nonce(bool enable) { enable_otu_nonce_ = enable; }
+
+  // Starts listening for packets from internal clients.
+  void AddInternalSocket(rtc::AsyncPacketSocket* socket,
+                         ProtocolType proto);
+  // Starts listening for the connections on this socket. When someone tries
+  // to connect, the connection will be accepted and a new internal socket
+  // will be added.
+  void AddInternalServerSocket(rtc::AsyncSocket* socket,
+                               ProtocolType proto);
+  // Specifies the factory to use for creating external sockets.
+  void SetExternalSocketFactory(rtc::PacketSocketFactory* factory,
+                                const rtc::SocketAddress& address);
+
+ private:
+  // Encapsulates the client's connection to the server.
+  class Connection {
+   public:
+    Connection() : proto_(PROTO_UDP), socket_(NULL) {}
+    Connection(const rtc::SocketAddress& src,
+               ProtocolType proto,
+               rtc::AsyncPacketSocket* socket);
+    const rtc::SocketAddress& src() const { return src_; }
+    rtc::AsyncPacketSocket* socket() { return socket_; }
+    bool operator==(const Connection& t) const;
+    bool operator<(const Connection& t) const;
+    std::string ToString() const;
+
+   private:
+    rtc::SocketAddress src_;
+    rtc::SocketAddress dst_;
+    cricket::ProtocolType proto_;
+    rtc::AsyncPacketSocket* socket_;
+  };
+  class Allocation;
+  class Permission;
+  class Channel;
+  typedef std::map<Connection, Allocation*> AllocationMap;
+
+  void OnInternalPacket(rtc::AsyncPacketSocket* socket, const char* data,
+                        size_t size, const rtc::SocketAddress& address,
+                        const rtc::PacketTime& packet_time);
+
+  void OnNewInternalConnection(rtc::AsyncSocket* socket);
+
+  // Accept connections on this server socket.
+  void AcceptConnection(rtc::AsyncSocket* server_socket);
+  void OnInternalSocketClose(rtc::AsyncPacketSocket* socket, int err);
+
+  void HandleStunMessage(Connection* conn, const char* data, size_t size);
+  void HandleBindingRequest(Connection* conn, const StunMessage* msg);
+  void HandleAllocateRequest(Connection* conn, const TurnMessage* msg,
+                             const std::string& key);
+
+  bool GetKey(const StunMessage* msg, std::string* key);
+  bool CheckAuthorization(Connection* conn, const StunMessage* msg,
+                          const char* data, size_t size,
+                          const std::string& key);
+  std::string GenerateNonce() const;
+  bool ValidateNonce(const std::string& nonce) const;
+
+  Allocation* FindAllocation(Connection* conn);
+  Allocation* CreateAllocation(Connection* conn, int proto,
+                               const std::string& key);
+
+  void SendErrorResponse(Connection* conn, const StunMessage* req,
+                         int code, const std::string& reason);
+
+  void SendErrorResponseWithRealmAndNonce(Connection* conn,
+                                          const StunMessage* req,
+                                          int code,
+                                          const std::string& reason);
+
+  void SendErrorResponseWithAlternateServer(Connection* conn,
+                                            const StunMessage* req,
+                                            const rtc::SocketAddress& addr);
+
+  void SendStun(Connection* conn, StunMessage* msg);
+  void Send(Connection* conn, const rtc::ByteBuffer& buf);
+
+  void OnAllocationDestroyed(Allocation* allocation);
+  void DestroyInternalSocket(rtc::AsyncPacketSocket* socket);
+
+  typedef std::map<rtc::AsyncPacketSocket*,
+                   ProtocolType> InternalSocketMap;
+  typedef std::map<rtc::AsyncSocket*,
+                   ProtocolType> ServerSocketMap;
+
+  rtc::Thread* thread_;
+  std::string nonce_key_;
+  std::string realm_;
+  std::string software_;
+  TurnAuthInterface* auth_hook_;
+  TurnRedirectInterface* redirect_hook_;
+  // otu - one-time-use. Server will respond with 438 if it's
+  // sees the same nonce in next transaction.
+  bool enable_otu_nonce_;
+
+  InternalSocketMap server_sockets_;
+  ServerSocketMap server_listen_sockets_;
+  rtc::scoped_ptr<rtc::PacketSocketFactory>
+      external_socket_factory_;
+  rtc::SocketAddress external_addr_;
+
+  AllocationMap allocations_;
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_TURNSERVER_H_
diff --git a/webrtc/p2p/base/udpport.h b/webrtc/p2p/base/udpport.h
new file mode 100644
index 0000000..9f86864
--- /dev/null
+++ b/webrtc/p2p/base/udpport.h
@@ -0,0 +1,17 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_UDPPORT_H_
+#define WEBRTC_P2P_BASE_UDPPORT_H_
+
+// StunPort will be handling UDPPort functionality.
+#include "webrtc/p2p/base/stunport.h"
+
+#endif  // WEBRTC_P2P_BASE_UDPPORT_H_
diff --git a/webrtc/p2p/client/autoportallocator.h b/webrtc/p2p/client/autoportallocator.h
new file mode 100644
index 0000000..5df1f0d
--- /dev/null
+++ b/webrtc/p2p/client/autoportallocator.h
@@ -0,0 +1,52 @@
+/*
+ *  Copyright 2010 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_CLIENT_AUTOPORTALLOCATOR_H_
+#define WEBRTC_P2P_CLIENT_AUTOPORTALLOCATOR_H_
+
+#include <string>
+#include <vector>
+
+#include "webrtc/p2p/client/httpportallocator.h"
+#include "webrtc/libjingle/xmpp/jingleinfotask.h"
+#include "webrtc/libjingle/xmpp/xmppclient.h"
+#include "webrtc/base/sigslot.h"
+
+// This class sets the relay and stun servers using XmppClient.
+// It enables the client to traverse Proxy and NAT.
+class AutoPortAllocator : public cricket::HttpPortAllocator {
+ public:
+  AutoPortAllocator(rtc::NetworkManager* network_manager,
+                    const std::string& user_agent)
+      : cricket::HttpPortAllocator(network_manager, user_agent) {
+  }
+
+  // Creates and initiates a task to get relay token from XmppClient and set
+  // it appropriately.
+  void SetXmppClient(buzz::XmppClient* client) {
+    // The JingleInfoTask is freed by the task-runner.
+    buzz::JingleInfoTask* jit = new buzz::JingleInfoTask(client);
+    jit->SignalJingleInfo.connect(this, &AutoPortAllocator::OnJingleInfo);
+    jit->Start();
+    jit->RefreshJingleInfoNow();
+  }
+
+ private:
+  void OnJingleInfo(
+      const std::string& token,
+      const std::vector<std::string>& relay_hosts,
+      const std::vector<rtc::SocketAddress>& stun_hosts) {
+    SetRelayToken(token);
+    SetStunHosts(stun_hosts);
+    SetRelayHosts(relay_hosts);
+  }
+};
+
+#endif  // WEBRTC_P2P_CLIENT_AUTOPORTALLOCATOR_H_
diff --git a/webrtc/p2p/client/basicportallocator.cc b/webrtc/p2p/client/basicportallocator.cc
new file mode 100644
index 0000000..5013a57
--- /dev/null
+++ b/webrtc/p2p/client/basicportallocator.cc
@@ -0,0 +1,1190 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/client/basicportallocator.h"
+
+#include <string>
+#include <vector>
+
+#include "webrtc/p2p/base/basicpacketsocketfactory.h"
+#include "webrtc/p2p/base/common.h"
+#include "webrtc/p2p/base/port.h"
+#include "webrtc/p2p/base/relayport.h"
+#include "webrtc/p2p/base/stunport.h"
+#include "webrtc/p2p/base/tcpport.h"
+#include "webrtc/p2p/base/turnport.h"
+#include "webrtc/p2p/base/udpport.h"
+#include "webrtc/base/common.h"
+#include "webrtc/base/helpers.h"
+#include "webrtc/base/logging.h"
+
+using rtc::CreateRandomId;
+using rtc::CreateRandomString;
+
+namespace {
+
+enum {
+  MSG_CONFIG_START,
+  MSG_CONFIG_READY,
+  MSG_ALLOCATE,
+  MSG_ALLOCATION_PHASE,
+  MSG_SHAKE,
+  MSG_SEQUENCEOBJECTS_CREATED,
+  MSG_CONFIG_STOP,
+};
+
+const int PHASE_UDP = 0;
+const int PHASE_RELAY = 1;
+const int PHASE_TCP = 2;
+const int PHASE_SSLTCP = 3;
+
+const int kNumPhases = 4;
+
+const int SHAKE_MIN_DELAY = 45 * 1000;  // 45 seconds
+const int SHAKE_MAX_DELAY = 90 * 1000;  // 90 seconds
+
+int ShakeDelay() {
+  int range = SHAKE_MAX_DELAY - SHAKE_MIN_DELAY + 1;
+  return SHAKE_MIN_DELAY + CreateRandomId() % range;
+}
+
+}  // namespace
+
+namespace cricket {
+
+const uint32 DISABLE_ALL_PHASES =
+  PORTALLOCATOR_DISABLE_UDP
+  | PORTALLOCATOR_DISABLE_TCP
+  | PORTALLOCATOR_DISABLE_STUN
+  | PORTALLOCATOR_DISABLE_RELAY;
+
+// Performs the allocation of ports, in a sequenced (timed) manner, for a given
+// network and IP address.
+class AllocationSequence : public rtc::MessageHandler,
+                           public sigslot::has_slots<> {
+ public:
+  enum State {
+    kInit,       // Initial state.
+    kRunning,    // Started allocating ports.
+    kStopped,    // Stopped from running.
+    kCompleted,  // All ports are allocated.
+
+    // kInit --> kRunning --> {kCompleted|kStopped}
+  };
+
+  AllocationSequence(BasicPortAllocatorSession* session,
+                     rtc::Network* network,
+                     PortConfiguration* config,
+                     uint32 flags);
+  ~AllocationSequence();
+  bool Init();
+  void Clear();
+
+  State state() const { return state_; }
+
+  // Disables the phases for a new sequence that this one already covers for an
+  // equivalent network setup.
+  void DisableEquivalentPhases(rtc::Network* network,
+      PortConfiguration* config, uint32* flags);
+
+  // Starts and stops the sequence.  When started, it will continue allocating
+  // new ports on its own timed schedule.
+  void Start();
+  void Stop();
+
+  // MessageHandler
+  void OnMessage(rtc::Message* msg);
+
+  void EnableProtocol(ProtocolType proto);
+  bool ProtocolEnabled(ProtocolType proto) const;
+
+  // Signal from AllocationSequence, when it's done with allocating ports.
+  // This signal is useful, when port allocation fails which doesn't result
+  // in any candidates. Using this signal BasicPortAllocatorSession can send
+  // its candidate discovery conclusion signal. Without this signal,
+  // BasicPortAllocatorSession doesn't have any event to trigger signal. This
+  // can also be achieved by starting timer in BPAS.
+  sigslot::signal1<AllocationSequence*> SignalPortAllocationComplete;
+
+ private:
+  typedef std::vector<ProtocolType> ProtocolList;
+
+  bool IsFlagSet(uint32 flag) {
+    return ((flags_ & flag) != 0);
+  }
+  void CreateUDPPorts();
+  void CreateTCPPorts();
+  void CreateStunPorts();
+  void CreateRelayPorts();
+  void CreateGturnPort(const RelayServerConfig& config);
+  void CreateTurnPort(const RelayServerConfig& config);
+
+  void OnReadPacket(rtc::AsyncPacketSocket* socket,
+                    const char* data, size_t size,
+                    const rtc::SocketAddress& remote_addr,
+                    const rtc::PacketTime& packet_time);
+
+  void OnPortDestroyed(PortInterface* port);
+
+  BasicPortAllocatorSession* session_;
+  rtc::Network* network_;
+  rtc::IPAddress ip_;
+  PortConfiguration* config_;
+  State state_;
+  uint32 flags_;
+  ProtocolList protocols_;
+  rtc::scoped_ptr<rtc::AsyncPacketSocket> udp_socket_;
+  // There will be only one udp port per AllocationSequence.
+  UDPPort* udp_port_;
+  std::vector<TurnPort*> turn_ports_;
+  int phase_;
+};
+
+// BasicPortAllocator
+BasicPortAllocator::BasicPortAllocator(
+    rtc::NetworkManager* network_manager,
+    rtc::PacketSocketFactory* socket_factory)
+    : network_manager_(network_manager),
+      socket_factory_(socket_factory) {
+  ASSERT(socket_factory_ != NULL);
+  Construct();
+}
+
+BasicPortAllocator::BasicPortAllocator(
+    rtc::NetworkManager* network_manager)
+    : network_manager_(network_manager),
+      socket_factory_(NULL) {
+  Construct();
+}
+
+BasicPortAllocator::BasicPortAllocator(
+    rtc::NetworkManager* network_manager,
+    rtc::PacketSocketFactory* socket_factory,
+    const ServerAddresses& stun_servers)
+    : network_manager_(network_manager),
+      socket_factory_(socket_factory),
+      stun_servers_(stun_servers) {
+  ASSERT(socket_factory_ != NULL);
+  Construct();
+}
+
+BasicPortAllocator::BasicPortAllocator(
+    rtc::NetworkManager* network_manager,
+    const ServerAddresses& stun_servers,
+    const rtc::SocketAddress& relay_address_udp,
+    const rtc::SocketAddress& relay_address_tcp,
+    const rtc::SocketAddress& relay_address_ssl)
+    : network_manager_(network_manager),
+      socket_factory_(NULL),
+      stun_servers_(stun_servers) {
+
+  RelayServerConfig config(RELAY_GTURN);
+  if (!relay_address_udp.IsNil())
+    config.ports.push_back(ProtocolAddress(relay_address_udp, PROTO_UDP));
+  if (!relay_address_tcp.IsNil())
+    config.ports.push_back(ProtocolAddress(relay_address_tcp, PROTO_TCP));
+  if (!relay_address_ssl.IsNil())
+    config.ports.push_back(ProtocolAddress(relay_address_ssl, PROTO_SSLTCP));
+
+  if (!config.ports.empty())
+    AddRelay(config);
+
+  Construct();
+}
+
+void BasicPortAllocator::Construct() {
+  allow_tcp_listen_ = true;
+}
+
+BasicPortAllocator::~BasicPortAllocator() {
+}
+
+PortAllocatorSession *BasicPortAllocator::CreateSessionInternal(
+    const std::string& content_name, int component,
+    const std::string& ice_ufrag, const std::string& ice_pwd) {
+  return new BasicPortAllocatorSession(
+      this, content_name, component, ice_ufrag, ice_pwd);
+}
+
+
+// BasicPortAllocatorSession
+BasicPortAllocatorSession::BasicPortAllocatorSession(
+    BasicPortAllocator *allocator,
+    const std::string& content_name,
+    int component,
+    const std::string& ice_ufrag,
+    const std::string& ice_pwd)
+    : PortAllocatorSession(content_name, component,
+                           ice_ufrag, ice_pwd, allocator->flags()),
+      allocator_(allocator), network_thread_(NULL),
+      socket_factory_(allocator->socket_factory()),
+      allocation_started_(false),
+      network_manager_started_(false),
+      running_(false),
+      allocation_sequences_created_(false) {
+  allocator_->network_manager()->SignalNetworksChanged.connect(
+      this, &BasicPortAllocatorSession::OnNetworksChanged);
+  allocator_->network_manager()->StartUpdating();
+}
+
+BasicPortAllocatorSession::~BasicPortAllocatorSession() {
+  allocator_->network_manager()->StopUpdating();
+  if (network_thread_ != NULL)
+    network_thread_->Clear(this);
+
+  for (uint32 i = 0; i < sequences_.size(); ++i) {
+    // AllocationSequence should clear it's map entry for turn ports before
+    // ports are destroyed.
+    sequences_[i]->Clear();
+  }
+
+  std::vector<PortData>::iterator it;
+  for (it = ports_.begin(); it != ports_.end(); it++)
+    delete it->port();
+
+  for (uint32 i = 0; i < configs_.size(); ++i)
+    delete configs_[i];
+
+  for (uint32 i = 0; i < sequences_.size(); ++i)
+    delete sequences_[i];
+}
+
+void BasicPortAllocatorSession::StartGettingPorts() {
+  network_thread_ = rtc::Thread::Current();
+  if (!socket_factory_) {
+    owned_socket_factory_.reset(
+        new rtc::BasicPacketSocketFactory(network_thread_));
+    socket_factory_ = owned_socket_factory_.get();
+  }
+
+  running_ = true;
+  network_thread_->Post(this, MSG_CONFIG_START);
+
+  if (flags() & PORTALLOCATOR_ENABLE_SHAKER)
+    network_thread_->PostDelayed(ShakeDelay(), this, MSG_SHAKE);
+}
+
+void BasicPortAllocatorSession::StopGettingPorts() {
+  ASSERT(rtc::Thread::Current() == network_thread_);
+  running_ = false;
+  network_thread_->Clear(this, MSG_ALLOCATE);
+  for (uint32 i = 0; i < sequences_.size(); ++i)
+    sequences_[i]->Stop();
+  network_thread_->Post(this, MSG_CONFIG_STOP);
+}
+
+void BasicPortAllocatorSession::OnMessage(rtc::Message *message) {
+  switch (message->message_id) {
+  case MSG_CONFIG_START:
+    ASSERT(rtc::Thread::Current() == network_thread_);
+    GetPortConfigurations();
+    break;
+
+  case MSG_CONFIG_READY:
+    ASSERT(rtc::Thread::Current() == network_thread_);
+    OnConfigReady(static_cast<PortConfiguration*>(message->pdata));
+    break;
+
+  case MSG_ALLOCATE:
+    ASSERT(rtc::Thread::Current() == network_thread_);
+    OnAllocate();
+    break;
+
+  case MSG_SHAKE:
+    ASSERT(rtc::Thread::Current() == network_thread_);
+    OnShake();
+    break;
+  case MSG_SEQUENCEOBJECTS_CREATED:
+    ASSERT(rtc::Thread::Current() == network_thread_);
+    OnAllocationSequenceObjectsCreated();
+    break;
+  case MSG_CONFIG_STOP:
+    ASSERT(rtc::Thread::Current() == network_thread_);
+    OnConfigStop();
+    break;
+  default:
+    ASSERT(false);
+  }
+}
+
+void BasicPortAllocatorSession::GetPortConfigurations() {
+  PortConfiguration* config = new PortConfiguration(allocator_->stun_servers(),
+                                                    username(),
+                                                    password());
+
+  for (size_t i = 0; i < allocator_->relays().size(); ++i) {
+    config->AddRelay(allocator_->relays()[i]);
+  }
+  ConfigReady(config);
+}
+
+void BasicPortAllocatorSession::ConfigReady(PortConfiguration* config) {
+  network_thread_->Post(this, MSG_CONFIG_READY, config);
+}
+
+// Adds a configuration to the list.
+void BasicPortAllocatorSession::OnConfigReady(PortConfiguration* config) {
+  if (config)
+    configs_.push_back(config);
+
+  AllocatePorts();
+}
+
+void BasicPortAllocatorSession::OnConfigStop() {
+  ASSERT(rtc::Thread::Current() == network_thread_);
+
+  // If any of the allocated ports have not completed the candidates allocation,
+  // mark those as error. Since session doesn't need any new candidates
+  // at this stage of the allocation, it's safe to discard any new candidates.
+  bool send_signal = false;
+  for (std::vector<PortData>::iterator it = ports_.begin();
+       it != ports_.end(); ++it) {
+    if (!it->complete()) {
+      // Updating port state to error, which didn't finish allocating candidates
+      // yet.
+      it->set_error();
+      send_signal = true;
+    }
+  }
+
+  // Did we stop any running sequences?
+  for (std::vector<AllocationSequence*>::iterator it = sequences_.begin();
+       it != sequences_.end() && !send_signal; ++it) {
+    if ((*it)->state() == AllocationSequence::kStopped) {
+      send_signal = true;
+    }
+  }
+
+  // If we stopped anything that was running, send a done signal now.
+  if (send_signal) {
+    MaybeSignalCandidatesAllocationDone();
+  }
+}
+
+void BasicPortAllocatorSession::AllocatePorts() {
+  ASSERT(rtc::Thread::Current() == network_thread_);
+  network_thread_->Post(this, MSG_ALLOCATE);
+}
+
+void BasicPortAllocatorSession::OnAllocate() {
+  if (network_manager_started_)
+    DoAllocate();
+
+  allocation_started_ = true;
+}
+
+// For each network, see if we have a sequence that covers it already.  If not,
+// create a new sequence to create the appropriate ports.
+void BasicPortAllocatorSession::DoAllocate() {
+  bool done_signal_needed = false;
+  std::vector<rtc::Network*> networks;
+  allocator_->network_manager()->GetNetworks(&networks);
+  if (networks.empty()) {
+    LOG(LS_WARNING) << "Machine has no networks; no ports will be allocated";
+    done_signal_needed = true;
+  } else {
+    for (uint32 i = 0; i < networks.size(); ++i) {
+      PortConfiguration* config = NULL;
+      if (configs_.size() > 0)
+        config = configs_.back();
+
+      uint32 sequence_flags = flags();
+      if ((sequence_flags & DISABLE_ALL_PHASES) == DISABLE_ALL_PHASES) {
+        // If all the ports are disabled we should just fire the allocation
+        // done event and return.
+        done_signal_needed = true;
+        break;
+      }
+
+      // Disables phases that are not specified in this config.
+      if (!config || config->StunServers().empty()) {
+        // No STUN ports specified in this config.
+        sequence_flags |= PORTALLOCATOR_DISABLE_STUN;
+      }
+      if (!config || config->relays.empty()) {
+        // No relay ports specified in this config.
+        sequence_flags |= PORTALLOCATOR_DISABLE_RELAY;
+      }
+
+      if (!(sequence_flags & PORTALLOCATOR_ENABLE_IPV6) &&
+#ifdef USE_WEBRTC_DEV_BRANCH
+          networks[i]->GetBestIP().family() == AF_INET6) {
+#else  // USE_WEBRTC_DEV_BRANCH
+          networks[i]->ip().family() == AF_INET6) {
+#endif  // USE_WEBRTC_DEV_BRANCH
+        // Skip IPv6 networks unless the flag's been set.
+        continue;
+      }
+
+      // Disable phases that would only create ports equivalent to
+      // ones that we have already made.
+      DisableEquivalentPhases(networks[i], config, &sequence_flags);
+
+      if ((sequence_flags & DISABLE_ALL_PHASES) == DISABLE_ALL_PHASES) {
+        // New AllocationSequence would have nothing to do, so don't make it.
+        continue;
+      }
+
+      AllocationSequence* sequence =
+          new AllocationSequence(this, networks[i], config, sequence_flags);
+      if (!sequence->Init()) {
+        delete sequence;
+        continue;
+      }
+      done_signal_needed = true;
+      sequence->SignalPortAllocationComplete.connect(
+          this, &BasicPortAllocatorSession::OnPortAllocationComplete);
+      if (running_)
+        sequence->Start();
+      sequences_.push_back(sequence);
+    }
+  }
+  if (done_signal_needed) {
+    network_thread_->Post(this, MSG_SEQUENCEOBJECTS_CREATED);
+  }
+}
+
+void BasicPortAllocatorSession::OnNetworksChanged() {
+  network_manager_started_ = true;
+  if (allocation_started_)
+    DoAllocate();
+}
+
+void BasicPortAllocatorSession::DisableEquivalentPhases(
+    rtc::Network* network, PortConfiguration* config, uint32* flags) {
+  for (uint32 i = 0; i < sequences_.size() &&
+      (*flags & DISABLE_ALL_PHASES) != DISABLE_ALL_PHASES; ++i) {
+    sequences_[i]->DisableEquivalentPhases(network, config, flags);
+  }
+}
+
+void BasicPortAllocatorSession::AddAllocatedPort(Port* port,
+                                                 AllocationSequence * seq,
+                                                 bool prepare_address) {
+  if (!port)
+    return;
+
+  LOG(LS_INFO) << "Adding allocated port for " << content_name();
+  port->set_content_name(content_name());
+  port->set_component(component_);
+  port->set_generation(generation());
+  if (allocator_->proxy().type != rtc::PROXY_NONE)
+    port->set_proxy(allocator_->user_agent(), allocator_->proxy());
+  port->set_send_retransmit_count_attribute((allocator_->flags() &
+      PORTALLOCATOR_ENABLE_STUN_RETRANSMIT_ATTRIBUTE) != 0);
+
+  // Push down the candidate_filter to individual port.
+  port->set_candidate_filter(allocator_->candidate_filter());
+
+  PortData data(port, seq);
+  ports_.push_back(data);
+
+  port->SignalCandidateReady.connect(
+      this, &BasicPortAllocatorSession::OnCandidateReady);
+  port->SignalPortComplete.connect(this,
+      &BasicPortAllocatorSession::OnPortComplete);
+  port->SignalDestroyed.connect(this,
+      &BasicPortAllocatorSession::OnPortDestroyed);
+  port->SignalPortError.connect(
+      this, &BasicPortAllocatorSession::OnPortError);
+  LOG_J(LS_INFO, port) << "Added port to allocator";
+
+  if (prepare_address)
+    port->PrepareAddress();
+}
+
+void BasicPortAllocatorSession::OnAllocationSequenceObjectsCreated() {
+  allocation_sequences_created_ = true;
+  // Send candidate allocation complete signal if we have no sequences.
+  MaybeSignalCandidatesAllocationDone();
+}
+
+void BasicPortAllocatorSession::OnCandidateReady(
+    Port* port, const Candidate& c) {
+  ASSERT(rtc::Thread::Current() == network_thread_);
+  PortData* data = FindPort(port);
+  ASSERT(data != NULL);
+  // Discarding any candidate signal if port allocation status is
+  // already in completed state.
+  if (data->complete())
+    return;
+
+  // Send candidates whose protocol is enabled.
+  std::vector<Candidate> candidates;
+  ProtocolType pvalue;
+  bool candidate_allowed_to_send = CheckCandidateFilter(c);
+  if (StringToProto(c.protocol().c_str(), &pvalue) &&
+      data->sequence()->ProtocolEnabled(pvalue) &&
+      candidate_allowed_to_send) {
+    candidates.push_back(c);
+  }
+
+  if (!candidates.empty()) {
+    SignalCandidatesReady(this, candidates);
+  }
+
+  // Moving to READY state as we have atleast one candidate from the port.
+  // Since this port has atleast one candidate we should forward this port
+  // to listners, to allow connections from this port.
+  // Also we should make sure that candidate gathered from this port is allowed
+  // to send outside.
+  if (!data->ready() && candidate_allowed_to_send) {
+    data->set_ready();
+    SignalPortReady(this, port);
+  }
+}
+
+void BasicPortAllocatorSession::OnPortComplete(Port* port) {
+  ASSERT(rtc::Thread::Current() == network_thread_);
+  PortData* data = FindPort(port);
+  ASSERT(data != NULL);
+
+  // Ignore any late signals.
+  if (data->complete())
+    return;
+
+  // Moving to COMPLETE state.
+  data->set_complete();
+  // Send candidate allocation complete signal if this was the last port.
+  MaybeSignalCandidatesAllocationDone();
+}
+
+void BasicPortAllocatorSession::OnPortError(Port* port) {
+  ASSERT(rtc::Thread::Current() == network_thread_);
+  PortData* data = FindPort(port);
+  ASSERT(data != NULL);
+  // We might have already given up on this port and stopped it.
+  if (data->complete())
+    return;
+
+  // SignalAddressError is currently sent from StunPort/TurnPort.
+  // But this signal itself is generic.
+  data->set_error();
+  // Send candidate allocation complete signal if this was the last port.
+  MaybeSignalCandidatesAllocationDone();
+}
+
+void BasicPortAllocatorSession::OnProtocolEnabled(AllocationSequence* seq,
+                                                  ProtocolType proto) {
+  std::vector<Candidate> candidates;
+  for (std::vector<PortData>::iterator it = ports_.begin();
+       it != ports_.end(); ++it) {
+    if (it->sequence() != seq)
+      continue;
+
+    const std::vector<Candidate>& potentials = it->port()->Candidates();
+    for (size_t i = 0; i < potentials.size(); ++i) {
+      if (!CheckCandidateFilter(potentials[i]))
+        continue;
+      ProtocolType pvalue;
+      if (!StringToProto(potentials[i].protocol().c_str(), &pvalue))
+        continue;
+      if (pvalue == proto) {
+        candidates.push_back(potentials[i]);
+      }
+    }
+  }
+
+  if (!candidates.empty()) {
+    SignalCandidatesReady(this, candidates);
+  }
+}
+
+bool BasicPortAllocatorSession::CheckCandidateFilter(const Candidate& c) {
+  uint32 filter = allocator_->candidate_filter();
+  bool allowed = false;
+  if (filter & CF_RELAY) {
+    allowed |= (c.type() == RELAY_PORT_TYPE);
+  }
+
+  if (filter & CF_REFLEXIVE) {
+    // We allow host candidates if the filter allows server-reflexive candidates
+    // and the candidate is a public IP. Because we don't generate
+    // server-reflexive candidates if they have the same IP as the host
+    // candidate (i.e. when the host candidate is a public IP), filtering to
+    // only server-reflexive candidates won't work right when the host
+    // candidates have public IPs.
+    allowed |= (c.type() == STUN_PORT_TYPE) ||
+               (c.type() == LOCAL_PORT_TYPE && !c.address().IsPrivateIP());
+  }
+
+  if (filter & CF_HOST) {
+    allowed |= (c.type() == LOCAL_PORT_TYPE);
+  }
+
+  return allowed;
+}
+
+void BasicPortAllocatorSession::OnPortAllocationComplete(
+    AllocationSequence* seq) {
+  // Send candidate allocation complete signal if all ports are done.
+  MaybeSignalCandidatesAllocationDone();
+}
+
+void BasicPortAllocatorSession::MaybeSignalCandidatesAllocationDone() {
+  // Send signal only if all required AllocationSequence objects
+  // are created.
+  if (!allocation_sequences_created_)
+    return;
+
+  // Check that all port allocation sequences are complete.
+  for (std::vector<AllocationSequence*>::iterator it = sequences_.begin();
+       it != sequences_.end(); ++it) {
+    if ((*it)->state() == AllocationSequence::kRunning)
+      return;
+  }
+
+  // If all allocated ports are in complete state, session must have got all
+  // expected candidates. Session will trigger candidates allocation complete
+  // signal.
+  for (std::vector<PortData>::iterator it = ports_.begin();
+       it != ports_.end(); ++it) {
+    if (!it->complete())
+      return;
+  }
+  LOG(LS_INFO) << "All candidates gathered for " << content_name_ << ":"
+               << component_ << ":" << generation();
+  SignalCandidatesAllocationDone(this);
+}
+
+void BasicPortAllocatorSession::OnPortDestroyed(
+    PortInterface* port) {
+  ASSERT(rtc::Thread::Current() == network_thread_);
+  for (std::vector<PortData>::iterator iter = ports_.begin();
+       iter != ports_.end(); ++iter) {
+    if (port == iter->port()) {
+      ports_.erase(iter);
+      LOG_J(LS_INFO, port) << "Removed port from allocator ("
+                           << static_cast<int>(ports_.size()) << " remaining)";
+      return;
+    }
+  }
+  ASSERT(false);
+}
+
+void BasicPortAllocatorSession::OnShake() {
+  LOG(INFO) << ">>>>> SHAKE <<<<< >>>>> SHAKE <<<<< >>>>> SHAKE <<<<<";
+
+  std::vector<Port*> ports;
+  std::vector<Connection*> connections;
+
+  for (size_t i = 0; i < ports_.size(); ++i) {
+    if (ports_[i].ready())
+      ports.push_back(ports_[i].port());
+  }
+
+  for (size_t i = 0; i < ports.size(); ++i) {
+    Port::AddressMap::const_iterator iter;
+    for (iter = ports[i]->connections().begin();
+         iter != ports[i]->connections().end();
+         ++iter) {
+      connections.push_back(iter->second);
+    }
+  }
+
+  LOG(INFO) << ">>>>> Destroying " << ports.size() << " ports and "
+            << connections.size() << " connections";
+
+  for (size_t i = 0; i < connections.size(); ++i)
+    connections[i]->Destroy();
+
+  if (running_ || (ports.size() > 0) || (connections.size() > 0))
+    network_thread_->PostDelayed(ShakeDelay(), this, MSG_SHAKE);
+}
+
+BasicPortAllocatorSession::PortData* BasicPortAllocatorSession::FindPort(
+    Port* port) {
+  for (std::vector<PortData>::iterator it = ports_.begin();
+       it != ports_.end(); ++it) {
+    if (it->port() == port) {
+      return &*it;
+    }
+  }
+  return NULL;
+}
+
+// AllocationSequence
+
+AllocationSequence::AllocationSequence(BasicPortAllocatorSession* session,
+                                       rtc::Network* network,
+                                       PortConfiguration* config,
+                                       uint32 flags)
+    : session_(session),
+      network_(network),
+
+#ifdef USE_WEBRTC_DEV_BRANCH
+      ip_(network->GetBestIP()),
+#else  // USE_WEBRTC_DEV_BRANCH
+      ip_(network->ip()),
+#endif  // USE_WEBRTC_DEV_BRANCH
+      config_(config),
+      state_(kInit),
+      flags_(flags),
+      udp_socket_(),
+      udp_port_(NULL),
+      phase_(0) {
+}
+
+bool AllocationSequence::Init() {
+  if (IsFlagSet(PORTALLOCATOR_ENABLE_SHARED_SOCKET) &&
+      !IsFlagSet(PORTALLOCATOR_ENABLE_SHARED_UFRAG)) {
+    LOG(LS_ERROR) << "Shared socket option can't be set without "
+                  << "shared ufrag.";
+    ASSERT(false);
+    return false;
+  }
+
+  if (IsFlagSet(PORTALLOCATOR_ENABLE_SHARED_SOCKET)) {
+    udp_socket_.reset(session_->socket_factory()->CreateUdpSocket(
+        rtc::SocketAddress(ip_, 0), session_->allocator()->min_port(),
+        session_->allocator()->max_port()));
+    if (udp_socket_) {
+      udp_socket_->SignalReadPacket.connect(
+          this, &AllocationSequence::OnReadPacket);
+    }
+    // Continuing if |udp_socket_| is NULL, as local TCP and RelayPort using TCP
+    // are next available options to setup a communication channel.
+  }
+  return true;
+}
+
+void AllocationSequence::Clear() {
+  udp_port_ = NULL;
+  turn_ports_.clear();
+}
+
+AllocationSequence::~AllocationSequence() {
+  session_->network_thread()->Clear(this);
+}
+
+void AllocationSequence::DisableEquivalentPhases(rtc::Network* network,
+    PortConfiguration* config, uint32* flags) {
+#ifdef USE_WEBRTC_DEV_BRANCH
+  if (!((network == network_) && (ip_ == network->GetBestIP()))) {
+#else  // USE_WEBRTC_DEV_BRANCH
+  if (!((network == network_) && (ip_ == network->ip()))) {
+#endif  // USE_WEBRTC_DEV_BRANCH
+    // Different network setup; nothing is equivalent.
+    return;
+  }
+
+  // Else turn off the stuff that we've already got covered.
+
+  // Every config implicitly specifies local, so turn that off right away.
+  *flags |= PORTALLOCATOR_DISABLE_UDP;
+  *flags |= PORTALLOCATOR_DISABLE_TCP;
+
+  if (config_ && config) {
+    if (config_->StunServers() == config->StunServers()) {
+      // Already got this STUN servers covered.
+      *flags |= PORTALLOCATOR_DISABLE_STUN;
+    }
+    if (!config_->relays.empty()) {
+      // Already got relays covered.
+      // NOTE: This will even skip a _different_ set of relay servers if we
+      // were to be given one, but that never happens in our codebase. Should
+      // probably get rid of the list in PortConfiguration and just keep a
+      // single relay server in each one.
+      *flags |= PORTALLOCATOR_DISABLE_RELAY;
+    }
+  }
+}
+
+void AllocationSequence::Start() {
+  state_ = kRunning;
+  session_->network_thread()->Post(this, MSG_ALLOCATION_PHASE);
+}
+
+void AllocationSequence::Stop() {
+  // If the port is completed, don't set it to stopped.
+  if (state_ == kRunning) {
+    state_ = kStopped;
+    session_->network_thread()->Clear(this, MSG_ALLOCATION_PHASE);
+  }
+}
+
+void AllocationSequence::OnMessage(rtc::Message* msg) {
+  ASSERT(rtc::Thread::Current() == session_->network_thread());
+  ASSERT(msg->message_id == MSG_ALLOCATION_PHASE);
+
+  const char* const PHASE_NAMES[kNumPhases] = {
+    "Udp", "Relay", "Tcp", "SslTcp"
+  };
+
+  // Perform all of the phases in the current step.
+  LOG_J(LS_INFO, network_) << "Allocation Phase="
+                           << PHASE_NAMES[phase_];
+
+  switch (phase_) {
+    case PHASE_UDP:
+      CreateUDPPorts();
+      CreateStunPorts();
+      EnableProtocol(PROTO_UDP);
+      break;
+
+    case PHASE_RELAY:
+      CreateRelayPorts();
+      break;
+
+    case PHASE_TCP:
+      CreateTCPPorts();
+      EnableProtocol(PROTO_TCP);
+      break;
+
+    case PHASE_SSLTCP:
+      state_ = kCompleted;
+      EnableProtocol(PROTO_SSLTCP);
+      break;
+
+    default:
+      ASSERT(false);
+  }
+
+  if (state() == kRunning) {
+    ++phase_;
+    session_->network_thread()->PostDelayed(
+        session_->allocator()->step_delay(),
+        this, MSG_ALLOCATION_PHASE);
+  } else {
+    // If all phases in AllocationSequence are completed, no allocation
+    // steps needed further. Canceling  pending signal.
+    session_->network_thread()->Clear(this, MSG_ALLOCATION_PHASE);
+    SignalPortAllocationComplete(this);
+  }
+}
+
+void AllocationSequence::EnableProtocol(ProtocolType proto) {
+  if (!ProtocolEnabled(proto)) {
+    protocols_.push_back(proto);
+    session_->OnProtocolEnabled(this, proto);
+  }
+}
+
+bool AllocationSequence::ProtocolEnabled(ProtocolType proto) const {
+  for (ProtocolList::const_iterator it = protocols_.begin();
+       it != protocols_.end(); ++it) {
+    if (*it == proto)
+      return true;
+  }
+  return false;
+}
+
+void AllocationSequence::CreateUDPPorts() {
+  if (IsFlagSet(PORTALLOCATOR_DISABLE_UDP)) {
+    LOG(LS_VERBOSE) << "AllocationSequence: UDP ports disabled, skipping.";
+    return;
+  }
+
+  // TODO(mallinath) - Remove UDPPort creating socket after shared socket
+  // is enabled completely.
+  UDPPort* port = NULL;
+  if (IsFlagSet(PORTALLOCATOR_ENABLE_SHARED_SOCKET) && udp_socket_) {
+    port = UDPPort::Create(session_->network_thread(),
+                           session_->socket_factory(), network_,
+                           udp_socket_.get(),
+                           session_->username(), session_->password());
+  } else {
+    port = UDPPort::Create(session_->network_thread(),
+                           session_->socket_factory(),
+                           network_, ip_,
+                           session_->allocator()->min_port(),
+                           session_->allocator()->max_port(),
+                           session_->username(), session_->password());
+  }
+
+  if (port) {
+    // If shared socket is enabled, STUN candidate will be allocated by the
+    // UDPPort.
+    if (IsFlagSet(PORTALLOCATOR_ENABLE_SHARED_SOCKET)) {
+      udp_port_ = port;
+
+      // If STUN is not disabled, setting stun server address to port.
+      if (!IsFlagSet(PORTALLOCATOR_DISABLE_STUN)) {
+        // If config has stun_servers, use it to get server reflexive candidate
+        // otherwise use first TURN server which supports UDP.
+        if (config_ && !config_->StunServers().empty()) {
+          LOG(LS_INFO) << "AllocationSequence: UDPPort will be handling the "
+                       <<  "STUN candidate generation.";
+          port->set_server_addresses(config_->StunServers());
+        } else if (config_ &&
+                   config_->SupportsProtocol(RELAY_TURN, PROTO_UDP)) {
+          port->set_server_addresses(config_->GetRelayServerAddresses(
+              RELAY_TURN, PROTO_UDP));
+          LOG(LS_INFO) << "AllocationSequence: TURN Server address will be "
+                       << " used for generating STUN candidate.";
+        }
+      }
+    }
+
+    session_->AddAllocatedPort(port, this, true);
+    port->SignalDestroyed.connect(this, &AllocationSequence::OnPortDestroyed);
+  }
+}
+
+void AllocationSequence::CreateTCPPorts() {
+  if (IsFlagSet(PORTALLOCATOR_DISABLE_TCP)) {
+    LOG(LS_VERBOSE) << "AllocationSequence: TCP ports disabled, skipping.";
+    return;
+  }
+
+  Port* port = TCPPort::Create(session_->network_thread(),
+                               session_->socket_factory(),
+                               network_, ip_,
+                               session_->allocator()->min_port(),
+                               session_->allocator()->max_port(),
+                               session_->username(), session_->password(),
+                               session_->allocator()->allow_tcp_listen());
+  if (port) {
+    session_->AddAllocatedPort(port, this, true);
+    // Since TCPPort is not created using shared socket, |port| will not be
+    // added to the dequeue.
+  }
+}
+
+void AllocationSequence::CreateStunPorts() {
+  if (IsFlagSet(PORTALLOCATOR_DISABLE_STUN)) {
+    LOG(LS_VERBOSE) << "AllocationSequence: STUN ports disabled, skipping.";
+    return;
+  }
+
+  if (IsFlagSet(PORTALLOCATOR_ENABLE_SHARED_SOCKET)) {
+    return;
+  }
+
+  // If BasicPortAllocatorSession::OnAllocate left STUN ports enabled then we
+  // ought to have an address for them here.
+  ASSERT(config_ && !config_->StunServers().empty());
+  if (!(config_ && !config_->StunServers().empty())) {
+    LOG(LS_WARNING)
+        << "AllocationSequence: No STUN server configured, skipping.";
+    return;
+  }
+
+  StunPort* port = StunPort::Create(session_->network_thread(),
+                                session_->socket_factory(),
+                                network_, ip_,
+                                session_->allocator()->min_port(),
+                                session_->allocator()->max_port(),
+                                session_->username(), session_->password(),
+                                config_->StunServers());
+  if (port) {
+    session_->AddAllocatedPort(port, this, true);
+    // Since StunPort is not created using shared socket, |port| will not be
+    // added to the dequeue.
+  }
+}
+
+void AllocationSequence::CreateRelayPorts() {
+  if (IsFlagSet(PORTALLOCATOR_DISABLE_RELAY)) {
+     LOG(LS_VERBOSE) << "AllocationSequence: Relay ports disabled, skipping.";
+     return;
+  }
+
+  // If BasicPortAllocatorSession::OnAllocate left relay ports enabled then we
+  // ought to have a relay list for them here.
+  ASSERT(config_ && !config_->relays.empty());
+  if (!(config_ && !config_->relays.empty())) {
+    LOG(LS_WARNING)
+        << "AllocationSequence: No relay server configured, skipping.";
+    return;
+  }
+
+  PortConfiguration::RelayList::const_iterator relay;
+  for (relay = config_->relays.begin();
+       relay != config_->relays.end(); ++relay) {
+    if (relay->type == RELAY_GTURN) {
+      CreateGturnPort(*relay);
+    } else if (relay->type == RELAY_TURN) {
+      CreateTurnPort(*relay);
+    } else {
+      ASSERT(false);
+    }
+  }
+}
+
+void AllocationSequence::CreateGturnPort(const RelayServerConfig& config) {
+  // TODO(mallinath) - Rename RelayPort to GTurnPort.
+  RelayPort* port = RelayPort::Create(session_->network_thread(),
+                                      session_->socket_factory(),
+                                      network_, ip_,
+                                      session_->allocator()->min_port(),
+                                      session_->allocator()->max_port(),
+                                      config_->username, config_->password);
+  if (port) {
+    // Since RelayPort is not created using shared socket, |port| will not be
+    // added to the dequeue.
+    // Note: We must add the allocated port before we add addresses because
+    //       the latter will create candidates that need name and preference
+    //       settings.  However, we also can't prepare the address (normally
+    //       done by AddAllocatedPort) until we have these addresses.  So we
+    //       wait to do that until below.
+    session_->AddAllocatedPort(port, this, false);
+
+    // Add the addresses of this protocol.
+    PortList::const_iterator relay_port;
+    for (relay_port = config.ports.begin();
+         relay_port != config.ports.end();
+         ++relay_port) {
+      port->AddServerAddress(*relay_port);
+      port->AddExternalAddress(*relay_port);
+    }
+    // Start fetching an address for this port.
+    port->PrepareAddress();
+  }
+}
+
+void AllocationSequence::CreateTurnPort(const RelayServerConfig& config) {
+  PortList::const_iterator relay_port;
+  for (relay_port = config.ports.begin();
+       relay_port != config.ports.end(); ++relay_port) {
+    TurnPort* port = NULL;
+    // Shared socket mode must be enabled only for UDP based ports. Hence
+    // don't pass shared socket for ports which will create TCP sockets.
+    // TODO(mallinath) - Enable shared socket mode for TURN ports. Disabled
+    // due to webrtc bug https://code.google.com/p/webrtc/issues/detail?id=3537
+    if (IsFlagSet(PORTALLOCATOR_ENABLE_SHARED_SOCKET) &&
+        relay_port->proto == PROTO_UDP) {
+      port = TurnPort::Create(session_->network_thread(),
+                              session_->socket_factory(),
+                              network_, udp_socket_.get(),
+                              session_->username(), session_->password(),
+                              *relay_port, config.credentials, config.priority);
+
+      turn_ports_.push_back(port);
+      // Listen to the port destroyed signal, to allow AllocationSequence to
+      // remove entrt from it's map.
+      port->SignalDestroyed.connect(this, &AllocationSequence::OnPortDestroyed);
+    } else {
+      port = TurnPort::Create(session_->network_thread(),
+                              session_->socket_factory(),
+                              network_, ip_,
+                              session_->allocator()->min_port(),
+                              session_->allocator()->max_port(),
+                              session_->username(),
+                              session_->password(),
+                              *relay_port, config.credentials, config.priority);
+    }
+    ASSERT(port != NULL);
+    session_->AddAllocatedPort(port, this, true);
+  }
+}
+
+void AllocationSequence::OnReadPacket(
+    rtc::AsyncPacketSocket* socket, const char* data, size_t size,
+    const rtc::SocketAddress& remote_addr,
+    const rtc::PacketTime& packet_time) {
+  ASSERT(socket == udp_socket_.get());
+
+  bool turn_port_found = false;
+
+  // Try to find the TurnPort that matches the remote address. Note that the
+  // message could be a STUN binding response if the TURN server is also used as
+  // a STUN server. We don't want to parse every message here to check if it is
+  // a STUN binding response, so we pass the message to TurnPort regardless of
+  // the message type. The TurnPort will just ignore the message since it will
+  // not find any request by transaction ID.
+  for (std::vector<TurnPort*>::const_iterator it = turn_ports_.begin();
+       it != turn_ports_.end(); ++it) {
+    TurnPort* port = *it;
+    if (port->server_address().address == remote_addr) {
+      port->HandleIncomingPacket(socket, data, size, remote_addr, packet_time);
+      turn_port_found = true;
+      break;
+    }
+  }
+
+  if (udp_port_) {
+    const ServerAddresses& stun_servers = udp_port_->server_addresses();
+
+    // Pass the packet to the UdpPort if there is no matching TurnPort, or if
+    // the TURN server is also a STUN server.
+    if (!turn_port_found ||
+        stun_servers.find(remote_addr) != stun_servers.end()) {
+      udp_port_->HandleIncomingPacket(
+          socket, data, size, remote_addr, packet_time);
+    }
+  }
+}
+
+void AllocationSequence::OnPortDestroyed(PortInterface* port) {
+  if (udp_port_ == port) {
+    udp_port_ = NULL;
+    return;
+  }
+
+  turn_ports_.erase(std::find(turn_ports_.begin(), turn_ports_.end(), port));
+}
+
+// PortConfiguration
+PortConfiguration::PortConfiguration(
+    const rtc::SocketAddress& stun_address,
+    const std::string& username,
+    const std::string& password)
+    : stun_address(stun_address), username(username), password(password) {
+  if (!stun_address.IsNil())
+    stun_servers.insert(stun_address);
+}
+
+PortConfiguration::PortConfiguration(const ServerAddresses& stun_servers,
+                                     const std::string& username,
+                                     const std::string& password)
+    : stun_servers(stun_servers),
+      username(username),
+      password(password) {
+  if (!stun_servers.empty())
+    stun_address = *(stun_servers.begin());
+}
+
+ServerAddresses PortConfiguration::StunServers() {
+  if (!stun_address.IsNil() &&
+      stun_servers.find(stun_address) == stun_servers.end()) {
+    stun_servers.insert(stun_address);
+  }
+  return stun_servers;
+}
+
+void PortConfiguration::AddRelay(const RelayServerConfig& config) {
+  relays.push_back(config);
+}
+
+bool PortConfiguration::SupportsProtocol(
+    const RelayServerConfig& relay, ProtocolType type) const {
+  PortList::const_iterator relay_port;
+  for (relay_port = relay.ports.begin();
+        relay_port != relay.ports.end();
+        ++relay_port) {
+    if (relay_port->proto == type)
+      return true;
+  }
+  return false;
+}
+
+bool PortConfiguration::SupportsProtocol(RelayType turn_type,
+                                         ProtocolType type) const {
+  for (size_t i = 0; i < relays.size(); ++i) {
+    if (relays[i].type == turn_type &&
+        SupportsProtocol(relays[i], type))
+      return true;
+  }
+  return false;
+}
+
+ServerAddresses PortConfiguration::GetRelayServerAddresses(
+    RelayType turn_type, ProtocolType type) const {
+  ServerAddresses servers;
+  for (size_t i = 0; i < relays.size(); ++i) {
+    if (relays[i].type == turn_type && SupportsProtocol(relays[i], type)) {
+      servers.insert(relays[i].ports.front().address);
+    }
+  }
+  return servers;
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/client/basicportallocator.h b/webrtc/p2p/client/basicportallocator.h
new file mode 100644
index 0000000..96468d3
--- /dev/null
+++ b/webrtc/p2p/client/basicportallocator.h
@@ -0,0 +1,241 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_CLIENT_BASICPORTALLOCATOR_H_
+#define WEBRTC_P2P_CLIENT_BASICPORTALLOCATOR_H_
+
+#include <string>
+#include <vector>
+
+#include "webrtc/p2p/base/port.h"
+#include "webrtc/p2p/base/portallocator.h"
+#include "webrtc/base/messagequeue.h"
+#include "webrtc/base/network.h"
+#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/thread.h"
+
+namespace cricket {
+
+struct RelayCredentials {
+  RelayCredentials() {}
+  RelayCredentials(const std::string& username,
+                   const std::string& password)
+      : username(username),
+        password(password) {
+  }
+
+  std::string username;
+  std::string password;
+};
+
+typedef std::vector<ProtocolAddress> PortList;
+struct RelayServerConfig {
+  RelayServerConfig(RelayType type) : type(type), priority(0) {}
+
+  RelayType type;
+  PortList ports;
+  RelayCredentials credentials;
+  int priority;
+};
+
+class BasicPortAllocator : public PortAllocator {
+ public:
+  BasicPortAllocator(rtc::NetworkManager* network_manager,
+                     rtc::PacketSocketFactory* socket_factory);
+  explicit BasicPortAllocator(rtc::NetworkManager* network_manager);
+  BasicPortAllocator(rtc::NetworkManager* network_manager,
+                     rtc::PacketSocketFactory* socket_factory,
+                     const ServerAddresses& stun_servers);
+  BasicPortAllocator(rtc::NetworkManager* network_manager,
+                     const ServerAddresses& stun_servers,
+                     const rtc::SocketAddress& relay_server_udp,
+                     const rtc::SocketAddress& relay_server_tcp,
+                     const rtc::SocketAddress& relay_server_ssl);
+  virtual ~BasicPortAllocator();
+
+  rtc::NetworkManager* network_manager() { return network_manager_; }
+
+  // If socket_factory() is set to NULL each PortAllocatorSession
+  // creates its own socket factory.
+  rtc::PacketSocketFactory* socket_factory() { return socket_factory_; }
+
+  const ServerAddresses& stun_servers() const {
+    return stun_servers_;
+  }
+
+  const std::vector<RelayServerConfig>& relays() const {
+    return relays_;
+  }
+  virtual void AddRelay(const RelayServerConfig& relay) {
+    relays_.push_back(relay);
+  }
+
+  virtual PortAllocatorSession* CreateSessionInternal(
+      const std::string& content_name,
+      int component,
+      const std::string& ice_ufrag,
+      const std::string& ice_pwd);
+
+ private:
+  void Construct();
+
+  rtc::NetworkManager* network_manager_;
+  rtc::PacketSocketFactory* socket_factory_;
+  const ServerAddresses stun_servers_;
+  std::vector<RelayServerConfig> relays_;
+  bool allow_tcp_listen_;
+};
+
+struct PortConfiguration;
+class AllocationSequence;
+
+class BasicPortAllocatorSession : public PortAllocatorSession,
+                                  public rtc::MessageHandler {
+ public:
+  BasicPortAllocatorSession(BasicPortAllocator* allocator,
+                            const std::string& content_name,
+                            int component,
+                            const std::string& ice_ufrag,
+                            const std::string& ice_pwd);
+  ~BasicPortAllocatorSession();
+
+  virtual BasicPortAllocator* allocator() { return allocator_; }
+  rtc::Thread* network_thread() { return network_thread_; }
+  rtc::PacketSocketFactory* socket_factory() { return socket_factory_; }
+
+  virtual void StartGettingPorts();
+  virtual void StopGettingPorts();
+  virtual bool IsGettingPorts() { return running_; }
+
+ protected:
+  // Starts the process of getting the port configurations.
+  virtual void GetPortConfigurations();
+
+  // Adds a port configuration that is now ready.  Once we have one for each
+  // network (or a timeout occurs), we will start allocating ports.
+  virtual void ConfigReady(PortConfiguration* config);
+
+  // MessageHandler.  Can be overriden if message IDs do not conflict.
+  virtual void OnMessage(rtc::Message *message);
+
+ private:
+  class PortData {
+   public:
+    PortData() : port_(NULL), sequence_(NULL), state_(STATE_INIT) {}
+    PortData(Port* port, AllocationSequence* seq)
+    : port_(port), sequence_(seq), state_(STATE_INIT) {
+    }
+
+    Port* port() { return port_; }
+    AllocationSequence* sequence() { return sequence_; }
+    bool ready() const { return state_ == STATE_READY; }
+    bool complete() const {
+      // Returns true if candidate allocation has completed one way or another.
+      return ((state_ == STATE_COMPLETE) || (state_ == STATE_ERROR));
+    }
+
+    void set_ready() { ASSERT(state_ == STATE_INIT); state_ = STATE_READY; }
+    void set_complete() {
+      state_ = STATE_COMPLETE;
+    }
+    void set_error() {
+      ASSERT(state_ == STATE_INIT || state_ == STATE_READY);
+      state_ = STATE_ERROR;
+    }
+
+   private:
+    enum State {
+      STATE_INIT,      // No candidates allocated yet.
+      STATE_READY,     // At least one candidate is ready for process.
+      STATE_COMPLETE,  // All candidates allocated and ready for process.
+      STATE_ERROR      // Error in gathering candidates.
+    };
+    Port* port_;
+    AllocationSequence* sequence_;
+    State state_;
+  };
+
+  void OnConfigReady(PortConfiguration* config);
+  void OnConfigStop();
+  void AllocatePorts();
+  void OnAllocate();
+  void DoAllocate();
+  void OnNetworksChanged();
+  void OnAllocationSequenceObjectsCreated();
+  void DisableEquivalentPhases(rtc::Network* network,
+                               PortConfiguration* config, uint32* flags);
+  void AddAllocatedPort(Port* port, AllocationSequence* seq,
+                        bool prepare_address);
+  void OnCandidateReady(Port* port, const Candidate& c);
+  void OnPortComplete(Port* port);
+  void OnPortError(Port* port);
+  void OnProtocolEnabled(AllocationSequence* seq, ProtocolType proto);
+  void OnPortDestroyed(PortInterface* port);
+  void OnShake();
+  void MaybeSignalCandidatesAllocationDone();
+  void OnPortAllocationComplete(AllocationSequence* seq);
+  PortData* FindPort(Port* port);
+
+  bool CheckCandidateFilter(const Candidate& c);
+
+  BasicPortAllocator* allocator_;
+  rtc::Thread* network_thread_;
+  rtc::scoped_ptr<rtc::PacketSocketFactory> owned_socket_factory_;
+  rtc::PacketSocketFactory* socket_factory_;
+  bool allocation_started_;
+  bool network_manager_started_;
+  bool running_;  // set when StartGetAllPorts is called
+  bool allocation_sequences_created_;
+  std::vector<PortConfiguration*> configs_;
+  std::vector<AllocationSequence*> sequences_;
+  std::vector<PortData> ports_;
+
+  friend class AllocationSequence;
+};
+
+// Records configuration information useful in creating ports.
+struct PortConfiguration : public rtc::MessageData {
+  // TODO(jiayl): remove |stun_address| when Chrome is updated.
+  rtc::SocketAddress stun_address;
+  ServerAddresses stun_servers;
+  std::string username;
+  std::string password;
+
+  typedef std::vector<RelayServerConfig> RelayList;
+  RelayList relays;
+
+  // TODO(jiayl): remove this ctor when Chrome is updated.
+  PortConfiguration(const rtc::SocketAddress& stun_address,
+                    const std::string& username,
+                    const std::string& password);
+
+  PortConfiguration(const ServerAddresses& stun_servers,
+                    const std::string& username,
+                    const std::string& password);
+
+  // TODO(jiayl): remove when |stun_address| is removed.
+  ServerAddresses StunServers();
+
+  // Adds another relay server, with the given ports and modifier, to the list.
+  void AddRelay(const RelayServerConfig& config);
+
+  // Determines whether the given relay server supports the given protocol.
+  bool SupportsProtocol(const RelayServerConfig& relay,
+                        ProtocolType type) const;
+  bool SupportsProtocol(RelayType turn_type, ProtocolType type) const;
+  // Helper method returns the server addresses for the matching RelayType and
+  // Protocol type.
+  ServerAddresses GetRelayServerAddresses(
+      RelayType turn_type, ProtocolType type) const;
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_CLIENT_BASICPORTALLOCATOR_H_
diff --git a/webrtc/p2p/client/connectivitychecker.cc b/webrtc/p2p/client/connectivitychecker.cc
new file mode 100644
index 0000000..6e3598e
--- /dev/null
+++ b/webrtc/p2p/client/connectivitychecker.cc
@@ -0,0 +1,573 @@
+/*
+ *  Copyright 2011 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <string>
+
+#include "webrtc/p2p/client/connectivitychecker.h"
+
+#include "webrtc/p2p/base/candidate.h"
+#include "webrtc/p2p/base/common.h"
+#include "webrtc/p2p/base/constants.h"
+#include "webrtc/p2p/base/port.h"
+#include "webrtc/p2p/base/relayport.h"
+#include "webrtc/p2p/base/stunport.h"
+#include "webrtc/base/asynchttprequest.h"
+#include "webrtc/base/autodetectproxy.h"
+#include "webrtc/base/helpers.h"
+#include "webrtc/base/httpcommon-inl.h"
+#include "webrtc/base/httpcommon.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/proxydetect.h"
+#include "webrtc/base/thread.h"
+
+namespace cricket {
+
+static const char kDefaultStunHostname[] = "stun.l.google.com";
+static const int kDefaultStunPort = 19302;
+
+// Default maximum time in milliseconds we will wait for connections.
+static const uint32 kDefaultTimeoutMs = 3000;
+
+enum {
+  MSG_START = 1,
+  MSG_STOP = 2,
+  MSG_TIMEOUT = 3,
+  MSG_SIGNAL_RESULTS = 4
+};
+
+class TestHttpPortAllocator : public HttpPortAllocator {
+ public:
+  TestHttpPortAllocator(rtc::NetworkManager* network_manager,
+                        const std::string& user_agent,
+                        const std::string& relay_token) :
+      HttpPortAllocator(network_manager, user_agent) {
+    SetRelayToken(relay_token);
+  }
+  PortAllocatorSession* CreateSessionInternal(
+      const std::string& content_name,
+      int component,
+      const std::string& ice_ufrag,
+      const std::string& ice_pwd) {
+    return new TestHttpPortAllocatorSession(this, content_name, component,
+                                            ice_ufrag, ice_pwd,
+                                            stun_hosts(), relay_hosts(),
+                                            relay_token(), user_agent());
+  }
+};
+
+void TestHttpPortAllocatorSession::ConfigReady(PortConfiguration* config) {
+  SignalConfigReady(username(), password(), config, proxy_);
+  delete config;
+}
+
+void TestHttpPortAllocatorSession::OnRequestDone(
+    rtc::SignalThread* data) {
+  rtc::AsyncHttpRequest* request =
+      static_cast<rtc::AsyncHttpRequest*>(data);
+
+  // Tell the checker that the request is complete.
+  SignalRequestDone(request);
+
+  // Pass on the response to super class.
+  HttpPortAllocatorSession::OnRequestDone(data);
+}
+
+ConnectivityChecker::ConnectivityChecker(
+    rtc::Thread* worker,
+    const std::string& jid,
+    const std::string& session_id,
+    const std::string& user_agent,
+    const std::string& relay_token,
+    const std::string& connection)
+    : worker_(worker),
+      jid_(jid),
+      session_id_(session_id),
+      user_agent_(user_agent),
+      relay_token_(relay_token),
+      connection_(connection),
+      proxy_detect_(NULL),
+      timeout_ms_(kDefaultTimeoutMs),
+      stun_address_(kDefaultStunHostname, kDefaultStunPort),
+      started_(false) {
+}
+
+ConnectivityChecker::~ConnectivityChecker() {
+  if (started_) {
+    // We try to clear the TIMEOUT below. But worker may still handle it and
+    // cause SignalCheckDone to happen on main-thread. So we finally clear any
+    // pending SIGNAL_RESULTS.
+    worker_->Clear(this, MSG_TIMEOUT);
+    worker_->Send(this, MSG_STOP);
+    nics_.clear();
+    main_->Clear(this, MSG_SIGNAL_RESULTS);
+  }
+}
+
+bool ConnectivityChecker::Initialize() {
+  network_manager_.reset(CreateNetworkManager());
+  socket_factory_.reset(CreateSocketFactory(worker_));
+  port_allocator_.reset(CreatePortAllocator(network_manager_.get(),
+                                            user_agent_, relay_token_));
+  uint32 new_allocator_flags = port_allocator_->flags();
+  new_allocator_flags |= cricket::PORTALLOCATOR_ENABLE_SHARED_UFRAG;
+  port_allocator_->set_flags(new_allocator_flags);
+  return true;
+}
+
+void ConnectivityChecker::Start() {
+  main_ = rtc::Thread::Current();
+  worker_->Post(this, MSG_START);
+  started_ = true;
+}
+
+void ConnectivityChecker::CleanUp() {
+  ASSERT(worker_ == rtc::Thread::Current());
+  if (proxy_detect_) {
+    proxy_detect_->Release();
+    proxy_detect_ = NULL;
+  }
+
+  for (uint32 i = 0; i < sessions_.size(); ++i) {
+    delete sessions_[i];
+  }
+  sessions_.clear();
+  for (uint32 i = 0; i < ports_.size(); ++i) {
+    delete ports_[i];
+  }
+  ports_.clear();
+}
+
+bool ConnectivityChecker::AddNic(const rtc::IPAddress& ip,
+                                 const rtc::SocketAddress& proxy_addr) {
+  NicMap::iterator i = nics_.find(NicId(ip, proxy_addr));
+  if (i != nics_.end()) {
+    // Already have it.
+    return false;
+  }
+  uint32 now = rtc::Time();
+  NicInfo info;
+  info.ip = ip;
+  info.proxy_info = GetProxyInfo();
+  info.stun.start_time_ms = now;
+  nics_.insert(std::pair<NicId, NicInfo>(NicId(ip, proxy_addr), info));
+  return true;
+}
+
+void ConnectivityChecker::SetProxyInfo(const rtc::ProxyInfo& proxy_info) {
+  port_allocator_->set_proxy(user_agent_, proxy_info);
+  AllocatePorts();
+}
+
+rtc::ProxyInfo ConnectivityChecker::GetProxyInfo() const {
+  rtc::ProxyInfo proxy_info;
+  if (proxy_detect_) {
+    proxy_info = proxy_detect_->proxy();
+  }
+  return proxy_info;
+}
+
+void ConnectivityChecker::CheckNetworks() {
+  network_manager_->SignalNetworksChanged.connect(
+      this, &ConnectivityChecker::OnNetworksChanged);
+  network_manager_->StartUpdating();
+}
+
+void ConnectivityChecker::OnMessage(rtc::Message *msg) {
+  switch (msg->message_id) {
+    case MSG_START:
+      ASSERT(worker_ == rtc::Thread::Current());
+      worker_->PostDelayed(timeout_ms_, this, MSG_TIMEOUT);
+      CheckNetworks();
+      break;
+    case MSG_STOP:
+      // We're being stopped, free resources.
+      CleanUp();
+      break;
+    case MSG_TIMEOUT:
+      // We need to signal results on the main thread.
+      main_->Post(this, MSG_SIGNAL_RESULTS);
+      break;
+    case MSG_SIGNAL_RESULTS:
+      ASSERT(main_ == rtc::Thread::Current());
+      SignalCheckDone(this);
+      break;
+    default:
+      LOG(LS_ERROR) << "Unknown message: " << msg->message_id;
+  }
+}
+
+void ConnectivityChecker::OnProxyDetect(rtc::SignalThread* thread) {
+  ASSERT(worker_ == rtc::Thread::Current());
+  if (proxy_detect_->proxy().type != rtc::PROXY_NONE) {
+    SetProxyInfo(proxy_detect_->proxy());
+  }
+}
+
+void ConnectivityChecker::OnRequestDone(rtc::AsyncHttpRequest* request) {
+  ASSERT(worker_ == rtc::Thread::Current());
+  // Since we don't know what nic were actually used for the http request,
+  // for now, just use the first one.
+  std::vector<rtc::Network*> networks;
+  network_manager_->GetNetworks(&networks);
+  if (networks.empty()) {
+    LOG(LS_ERROR) << "No networks while registering http start.";
+    return;
+  }
+  rtc::ProxyInfo proxy_info = request->proxy();
+  NicMap::iterator i =
+#ifdef USE_WEBRTC_DEV_BRANCH
+      nics_.find(NicId(networks[0]->GetBestIP(), proxy_info.address));
+#else  // USE_WEBRTC_DEV_BRANCH
+      nics_.find(NicId(networks[0]->ip(), proxy_info.address));
+#endif  // USE_WEBRTC_DEV_BRANCH
+  if (i != nics_.end()) {
+    int port = request->port();
+    uint32 now = rtc::Time();
+    NicInfo* nic_info = &i->second;
+    if (port == rtc::HTTP_DEFAULT_PORT) {
+      nic_info->http.rtt = now - nic_info->http.start_time_ms;
+    } else if (port == rtc::HTTP_SECURE_PORT) {
+      nic_info->https.rtt = now - nic_info->https.start_time_ms;
+    } else {
+      LOG(LS_ERROR) << "Got response with unknown port: " << port;
+    }
+  } else {
+    LOG(LS_ERROR) << "No nic info found while receiving response.";
+  }
+}
+
+void ConnectivityChecker::OnConfigReady(
+    const std::string& username, const std::string& password,
+    const PortConfiguration* config, const rtc::ProxyInfo& proxy_info) {
+  ASSERT(worker_ == rtc::Thread::Current());
+
+  // Since we send requests on both HTTP and HTTPS we will get two
+  // configs per nic. Results from the second will overwrite the
+  // result from the first.
+  // TODO: Handle multiple pings on one nic.
+  CreateRelayPorts(username, password, config, proxy_info);
+}
+
+void ConnectivityChecker::OnRelayPortComplete(Port* port) {
+  ASSERT(worker_ == rtc::Thread::Current());
+  RelayPort* relay_port = reinterpret_cast<RelayPort*>(port);
+  const ProtocolAddress* address = relay_port->ServerAddress(0);
+#ifdef USE_WEBRTC_DEV_BRANCH
+  rtc::IPAddress ip = port->Network()->GetBestIP();
+#else  // USE_WEBRTC_DEV_BRANCH
+  rtc::IPAddress ip = port->Network()->ip();
+#endif  // USE_WEBRTC_DEV_BRANCH
+  NicMap::iterator i = nics_.find(NicId(ip, port->proxy().address));
+  if (i != nics_.end()) {
+    // We have it already, add the new information.
+    NicInfo* nic_info = &i->second;
+    ConnectInfo* connect_info = NULL;
+    if (address) {
+      switch (address->proto) {
+        case PROTO_UDP:
+          connect_info = &nic_info->udp;
+          break;
+        case PROTO_TCP:
+          connect_info = &nic_info->tcp;
+          break;
+        case PROTO_SSLTCP:
+          connect_info = &nic_info->ssltcp;
+          break;
+        default:
+          LOG(LS_ERROR) << " relay address with bad protocol added";
+      }
+      if (connect_info) {
+        connect_info->rtt =
+            rtc::TimeSince(connect_info->start_time_ms);
+      }
+    }
+  } else {
+    LOG(LS_ERROR) << " got relay address for non-existing nic";
+  }
+}
+
+void ConnectivityChecker::OnStunPortComplete(Port* port) {
+  ASSERT(worker_ == rtc::Thread::Current());
+  const std::vector<Candidate> candidates = port->Candidates();
+  Candidate c = candidates[0];
+#ifdef USE_WEBRTC_DEV_BRANCH
+  rtc::IPAddress ip = port->Network()->GetBestIP();
+#else  // USE_WEBRTC_DEV_BRANCH
+  rtc::IPAddress ip = port->Network()->ip();
+#endif  // USE_WEBRTC_DEV_BRANCH
+  NicMap::iterator i = nics_.find(NicId(ip, port->proxy().address));
+  if (i != nics_.end()) {
+    // We have it already, add the new information.
+    uint32 now = rtc::Time();
+    NicInfo* nic_info = &i->second;
+    nic_info->external_address = c.address();
+
+    nic_info->stun_server_addresses =
+        static_cast<StunPort*>(port)->server_addresses();
+    nic_info->stun.rtt = now - nic_info->stun.start_time_ms;
+  } else {
+    LOG(LS_ERROR) << "Got stun address for non-existing nic";
+  }
+}
+
+void ConnectivityChecker::OnStunPortError(Port* port) {
+  ASSERT(worker_ == rtc::Thread::Current());
+  LOG(LS_ERROR) << "Stun address error.";
+#ifdef USE_WEBRTC_DEV_BRANCH
+  rtc::IPAddress ip = port->Network()->GetBestIP();
+#else  // USE_WEBRTC_DEV_BRANCH
+  rtc::IPAddress ip = port->Network()->ip();
+#endif  // USE_WEBRTC_DEV_BRANCH
+  NicMap::iterator i = nics_.find(NicId(ip, port->proxy().address));
+  if (i != nics_.end()) {
+    // We have it already, add the new information.
+    NicInfo* nic_info = &i->second;
+
+    nic_info->stun_server_addresses =
+        static_cast<StunPort*>(port)->server_addresses();
+  }
+}
+
+void ConnectivityChecker::OnRelayPortError(Port* port) {
+  ASSERT(worker_ == rtc::Thread::Current());
+  LOG(LS_ERROR) << "Relay address error.";
+}
+
+void ConnectivityChecker::OnNetworksChanged() {
+  ASSERT(worker_ == rtc::Thread::Current());
+  std::vector<rtc::Network*> networks;
+  network_manager_->GetNetworks(&networks);
+  if (networks.empty()) {
+    LOG(LS_ERROR) << "Machine has no networks; nothing to do";
+    return;
+  }
+  AllocatePorts();
+}
+
+HttpPortAllocator* ConnectivityChecker::CreatePortAllocator(
+    rtc::NetworkManager* network_manager,
+    const std::string& user_agent,
+    const std::string& relay_token) {
+  return new TestHttpPortAllocator(network_manager, user_agent, relay_token);
+}
+
+StunPort* ConnectivityChecker::CreateStunPort(
+    const std::string& username, const std::string& password,
+    const PortConfiguration* config, rtc::Network* network) {
+  return StunPort::Create(worker_,
+                          socket_factory_.get(),
+                          network,
+#ifdef USE_WEBRTC_DEV_BRANCH
+                          network->GetBestIP(),
+#else  // USE_WEBRTC_DEV_BRANCH
+                          network->ip(),
+#endif  // USE_WEBRTC_DEV_BRANCH
+                          0,
+                          0,
+                          username,
+                          password,
+                          config->stun_servers);
+}
+
+RelayPort* ConnectivityChecker::CreateRelayPort(
+    const std::string& username, const std::string& password,
+    const PortConfiguration* config, rtc::Network* network) {
+  return RelayPort::Create(worker_,
+                           socket_factory_.get(),
+                           network,
+#ifdef USE_WEBRTC_DEV_BRANCH
+                           network->GetBestIP(),
+#else  // USE_WEBRTC_DEV_BRANCH
+                           network->ip(),
+#endif  // USE_WEBRTC_DEV_BRANCH
+                           port_allocator_->min_port(),
+                           port_allocator_->max_port(),
+                           username,
+                           password);
+}
+
+void ConnectivityChecker::CreateRelayPorts(
+    const std::string& username, const std::string& password,
+    const PortConfiguration* config, const rtc::ProxyInfo& proxy_info) {
+  PortConfiguration::RelayList::const_iterator relay;
+  std::vector<rtc::Network*> networks;
+  network_manager_->GetNetworks(&networks);
+  if (networks.empty()) {
+    LOG(LS_ERROR) << "Machine has no networks; no relay ports created.";
+    return;
+  }
+  for (relay = config->relays.begin();
+       relay != config->relays.end(); ++relay) {
+    for (uint32 i = 0; i < networks.size(); ++i) {
+      NicMap::iterator iter =
+#ifdef USE_WEBRTC_DEV_BRANCH
+          nics_.find(NicId(networks[i]->GetBestIP(), proxy_info.address));
+#else  // USE_WEBRTC_DEV_BRANCH
+          nics_.find(NicId(networks[i]->ip(), proxy_info.address));
+#endif  // USE_WEBRTC_DEV_BRANCH
+      if (iter != nics_.end()) {
+        // TODO: Now setting the same start time for all protocols.
+        // This might affect accuracy, but since we are mainly looking for
+        // connect failures or number that stick out, this is good enough.
+        uint32 now = rtc::Time();
+        NicInfo* nic_info = &iter->second;
+        nic_info->udp.start_time_ms = now;
+        nic_info->tcp.start_time_ms = now;
+        nic_info->ssltcp.start_time_ms = now;
+
+        // Add the addresses of this protocol.
+        PortList::const_iterator relay_port;
+        for (relay_port = relay->ports.begin();
+             relay_port != relay->ports.end();
+             ++relay_port) {
+          RelayPort* port = CreateRelayPort(username, password,
+                                            config, networks[i]);
+          port->AddServerAddress(*relay_port);
+          port->AddExternalAddress(*relay_port);
+
+          nic_info->media_server_address = port->ServerAddress(0)->address;
+
+          // Listen to network events.
+          port->SignalPortComplete.connect(
+              this, &ConnectivityChecker::OnRelayPortComplete);
+          port->SignalPortError.connect(
+              this, &ConnectivityChecker::OnRelayPortError);
+
+          port->set_proxy(user_agent_, proxy_info);
+
+          // Start fetching an address for this port.
+          port->PrepareAddress();
+          ports_.push_back(port);
+        }
+      } else {
+        LOG(LS_ERROR) << "Failed to find nic info when creating relay ports.";
+      }
+    }
+  }
+}
+
+void ConnectivityChecker::AllocatePorts() {
+  const std::string username = rtc::CreateRandomString(ICE_UFRAG_LENGTH);
+  const std::string password = rtc::CreateRandomString(ICE_PWD_LENGTH);
+  ServerAddresses stun_servers;
+  stun_servers.insert(stun_address_);
+  PortConfiguration config(stun_servers, username, password);
+  std::vector<rtc::Network*> networks;
+  network_manager_->GetNetworks(&networks);
+  if (networks.empty()) {
+    LOG(LS_ERROR) << "Machine has no networks; no ports will be allocated";
+    return;
+  }
+  rtc::ProxyInfo proxy_info = GetProxyInfo();
+  bool allocate_relay_ports = false;
+  for (uint32 i = 0; i < networks.size(); ++i) {
+#ifdef USE_WEBRTC_DEV_BRANCH
+    if (AddNic(networks[i]->GetBestIP(), proxy_info.address)) {
+#else  // USE_WEBRTC_DEV_BRANCH
+    if (AddNic(networks[i]->ip(), proxy_info.address)) {
+#endif  // USE_WEBRTC_DEV_BRANCH
+      Port* port = CreateStunPort(username, password, &config, networks[i]);
+      if (port) {
+
+        // Listen to network events.
+        port->SignalPortComplete.connect(
+            this, &ConnectivityChecker::OnStunPortComplete);
+        port->SignalPortError.connect(
+            this, &ConnectivityChecker::OnStunPortError);
+
+        port->set_proxy(user_agent_, proxy_info);
+        port->PrepareAddress();
+        ports_.push_back(port);
+        allocate_relay_ports = true;
+      }
+    }
+  }
+
+  // If any new ip/proxy combinations were added, send a relay allocate.
+  if (allocate_relay_ports) {
+    AllocateRelayPorts();
+  }
+
+  // Initiate proxy detection.
+  InitiateProxyDetection();
+}
+
+void ConnectivityChecker::InitiateProxyDetection() {
+  // Only start if we haven't been started before.
+  if (!proxy_detect_) {
+    proxy_detect_ = new rtc::AutoDetectProxy(user_agent_);
+    rtc::Url<char> host_url("/", "relay.google.com",
+                                  rtc::HTTP_DEFAULT_PORT);
+    host_url.set_secure(true);
+    proxy_detect_->set_server_url(host_url.url());
+    proxy_detect_->SignalWorkDone.connect(
+        this, &ConnectivityChecker::OnProxyDetect);
+    proxy_detect_->Start();
+  }
+}
+
+void ConnectivityChecker::AllocateRelayPorts() {
+  // Currently we are using the 'default' nic for http(s) requests.
+  TestHttpPortAllocatorSession* allocator_session =
+      reinterpret_cast<TestHttpPortAllocatorSession*>(
+          port_allocator_->CreateSessionInternal(
+              "connectivity checker test content",
+              ICE_CANDIDATE_COMPONENT_RTP,
+              rtc::CreateRandomString(ICE_UFRAG_LENGTH),
+              rtc::CreateRandomString(ICE_PWD_LENGTH)));
+  allocator_session->set_proxy(port_allocator_->proxy());
+  allocator_session->SignalConfigReady.connect(
+      this, &ConnectivityChecker::OnConfigReady);
+  allocator_session->SignalRequestDone.connect(
+      this, &ConnectivityChecker::OnRequestDone);
+
+  // Try both http and https.
+  RegisterHttpStart(rtc::HTTP_SECURE_PORT);
+  allocator_session->SendSessionRequest("relay.l.google.com",
+                                        rtc::HTTP_SECURE_PORT);
+  RegisterHttpStart(rtc::HTTP_DEFAULT_PORT);
+  allocator_session->SendSessionRequest("relay.l.google.com",
+                                        rtc::HTTP_DEFAULT_PORT);
+
+  sessions_.push_back(allocator_session);
+}
+
+void ConnectivityChecker::RegisterHttpStart(int port) {
+  // Since we don't know what nic were actually used for the http request,
+  // for now, just use the first one.
+  std::vector<rtc::Network*> networks;
+  network_manager_->GetNetworks(&networks);
+  if (networks.empty()) {
+    LOG(LS_ERROR) << "No networks while registering http start.";
+    return;
+  }
+  rtc::ProxyInfo proxy_info = GetProxyInfo();
+  NicMap::iterator i =
+#ifdef USE_WEBRTC_DEV_BRANCH
+      nics_.find(NicId(networks[0]->GetBestIP(), proxy_info.address));
+#else  // USE_WEBRTC_DEV_BRANCH
+      nics_.find(NicId(networks[0]->ip(), proxy_info.address));
+#endif  // USE_WEBRTC_DEV_BRANCH
+  if (i != nics_.end()) {
+    uint32 now = rtc::Time();
+    NicInfo* nic_info = &i->second;
+    if (port == rtc::HTTP_DEFAULT_PORT) {
+      nic_info->http.start_time_ms = now;
+    } else if (port == rtc::HTTP_SECURE_PORT) {
+      nic_info->https.start_time_ms = now;
+    } else {
+      LOG(LS_ERROR) << "Registering start time for unknown port: " << port;
+    }
+  } else {
+    LOG(LS_ERROR) << "Error, no nic info found while registering http start.";
+  }
+}
+
+}  // namespace rtc
diff --git a/webrtc/p2p/client/connectivitychecker.h b/webrtc/p2p/client/connectivitychecker.h
new file mode 100644
index 0000000..427749e
--- /dev/null
+++ b/webrtc/p2p/client/connectivitychecker.h
@@ -0,0 +1,281 @@
+/*
+ *  Copyright 2011 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_CLIENT_CONNECTIVITYCHECKER_H_
+#define WEBRTC_P2P_CLIENT_CONNECTIVITYCHECKER_H_
+
+#include <map>
+#include <string>
+
+#include "webrtc/p2p/base/basicpacketsocketfactory.h"
+#include "webrtc/p2p/client/httpportallocator.h"
+#include "webrtc/base/basictypes.h"
+#include "webrtc/base/messagehandler.h"
+#include "webrtc/base/network.h"
+#include "webrtc/base/proxyinfo.h"
+#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/sigslot.h"
+#include "webrtc/base/socketaddress.h"
+
+namespace rtc {
+class AsyncHttpRequest;
+class AutoDetectProxy;
+class BasicPacketSocketFactory;
+class NetworkManager;
+class PacketSocketFactory;
+class SignalThread;
+class TestHttpPortAllocatorSession;
+class Thread;
+}
+
+namespace cricket {
+class HttpPortAllocator;
+class Port;
+class PortAllocatorSession;
+struct PortConfiguration;
+class RelayPort;
+class StunPort;
+
+// Contains details about a discovered firewall that are of interest
+// when debugging call failures.
+struct FirewallInfo {
+  std::string brand;
+  std::string model;
+
+  // TODO: List of current port mappings.
+};
+
+// Contains details about a specific connect attempt.
+struct ConnectInfo {
+  ConnectInfo()
+      : rtt(-1), error(0) {}
+  // Time when the connection was initiated. Needed for calculating
+  // the round trip time.
+  uint32 start_time_ms;
+  // Round trip time in milliseconds or -1 for failed connection.
+  int32 rtt;
+  // Error code representing low level errors like socket errors.
+  int error;
+};
+
+// Identifier for a network interface and proxy address pair.
+struct NicId {
+  NicId(const rtc::IPAddress& ip,
+        const rtc::SocketAddress& proxy_address)
+      : ip(ip),
+        proxy_address(proxy_address) {
+  }
+  rtc::IPAddress ip;
+  rtc::SocketAddress proxy_address;
+};
+
+// Comparator implementation identifying unique network interface and
+// proxy address pairs.
+class NicIdComparator {
+ public:
+  int compare(const NicId &first, const NicId &second) const {
+    if (first.ip == second.ip) {
+      // Compare proxy address.
+      if (first.proxy_address == second.proxy_address) {
+        return 0;
+      } else {
+        return first.proxy_address < second.proxy_address? -1 : 1;
+      }
+    }
+    return first.ip < second.ip ? -1 : 1;
+  }
+
+  bool operator()(const NicId &first, const NicId &second) const {
+    return (compare(first, second) < 0);
+  }
+};
+
+// Contains information of a network interface and proxy address pair.
+struct NicInfo {
+  NicInfo() {}
+  rtc::IPAddress ip;
+  rtc::ProxyInfo proxy_info;
+  rtc::SocketAddress external_address;
+  ServerAddresses stun_server_addresses;
+  rtc::SocketAddress media_server_address;
+  ConnectInfo stun;
+  ConnectInfo http;
+  ConnectInfo https;
+  ConnectInfo udp;
+  ConnectInfo tcp;
+  ConnectInfo ssltcp;
+  FirewallInfo firewall;
+};
+
+// Holds the result of the connectivity check.
+class NicMap : public std::map<NicId, NicInfo, NicIdComparator> {
+};
+
+class TestHttpPortAllocatorSession : public HttpPortAllocatorSession {
+ public:
+  TestHttpPortAllocatorSession(
+      HttpPortAllocator* allocator,
+      const std::string& content_name,
+      int component,
+      const std::string& ice_ufrag,
+      const std::string& ice_pwd,
+      const std::vector<rtc::SocketAddress>& stun_hosts,
+      const std::vector<std::string>& relay_hosts,
+      const std::string& relay_token,
+      const std::string& user_agent)
+      : HttpPortAllocatorSession(
+          allocator, content_name, component, ice_ufrag, ice_pwd, stun_hosts,
+          relay_hosts, relay_token, user_agent) {
+  }
+  void set_proxy(const rtc::ProxyInfo& proxy) {
+    proxy_ = proxy;
+  }
+
+  void ConfigReady(PortConfiguration* config);
+
+  void OnRequestDone(rtc::SignalThread* data);
+
+  sigslot::signal4<const std::string&, const std::string&,
+                   const PortConfiguration*,
+                   const rtc::ProxyInfo&> SignalConfigReady;
+  sigslot::signal1<rtc::AsyncHttpRequest*> SignalRequestDone;
+
+ private:
+  rtc::ProxyInfo proxy_;
+};
+
+// Runs a request/response check on all network interface and proxy
+// address combinations. The check is considered done either when all
+// checks has been successful or when the check times out.
+class ConnectivityChecker
+    : public rtc::MessageHandler, public sigslot::has_slots<> {
+ public:
+  ConnectivityChecker(rtc::Thread* worker,
+                      const std::string& jid,
+                      const std::string& session_id,
+                      const std::string& user_agent,
+                      const std::string& relay_token,
+                      const std::string& connection);
+  virtual ~ConnectivityChecker();
+
+  // Virtual for gMock.
+  virtual bool Initialize();
+  virtual void Start();
+
+  // MessageHandler implementation.
+  virtual void OnMessage(rtc::Message *msg);
+
+  // Instruct checker to stop and wait until that's done.
+  // Virtual for gMock.
+  virtual void Stop() {
+    worker_->Stop();
+  }
+
+  const NicMap& GetResults() const {
+    return nics_;
+  }
+
+  void set_timeout_ms(uint32 timeout) {
+    timeout_ms_ = timeout;
+  }
+
+  void set_stun_address(const rtc::SocketAddress& stun_address) {
+    stun_address_ = stun_address;
+  }
+
+  const std::string& connection() const {
+    return connection_;
+  }
+
+  const std::string& jid() const {
+    return jid_;
+  }
+
+  const std::string& session_id() const {
+    return session_id_;
+  }
+
+  // Context: Main Thread. Signalled when the connectivity check is complete.
+  sigslot::signal1<ConnectivityChecker*> SignalCheckDone;
+
+ protected:
+  // Can be overridden for test.
+  virtual rtc::NetworkManager* CreateNetworkManager() {
+    return new rtc::BasicNetworkManager();
+  }
+  virtual rtc::BasicPacketSocketFactory* CreateSocketFactory(
+      rtc::Thread* thread) {
+    return new rtc::BasicPacketSocketFactory(thread);
+  }
+  virtual HttpPortAllocator* CreatePortAllocator(
+      rtc::NetworkManager* network_manager,
+      const std::string& user_agent,
+      const std::string& relay_token);
+  virtual StunPort* CreateStunPort(
+      const std::string& username, const std::string& password,
+      const PortConfiguration* config, rtc::Network* network);
+  virtual RelayPort* CreateRelayPort(
+      const std::string& username, const std::string& password,
+      const PortConfiguration* config, rtc::Network* network);
+  virtual void InitiateProxyDetection();
+  virtual void SetProxyInfo(const rtc::ProxyInfo& info);
+  virtual rtc::ProxyInfo GetProxyInfo() const;
+
+  rtc::Thread* worker() {
+    return worker_;
+  }
+
+ private:
+  bool AddNic(const rtc::IPAddress& ip,
+              const rtc::SocketAddress& proxy_address);
+  void AllocatePorts();
+  void AllocateRelayPorts();
+  void CheckNetworks();
+  void CreateRelayPorts(
+      const std::string& username, const std::string& password,
+      const PortConfiguration* config, const rtc::ProxyInfo& proxy_info);
+
+  // Must be called by the worker thread.
+  void CleanUp();
+
+  void OnRequestDone(rtc::AsyncHttpRequest* request);
+  void OnRelayPortComplete(Port* port);
+  void OnStunPortComplete(Port* port);
+  void OnRelayPortError(Port* port);
+  void OnStunPortError(Port* port);
+  void OnNetworksChanged();
+  void OnProxyDetect(rtc::SignalThread* thread);
+  void OnConfigReady(
+      const std::string& username, const std::string& password,
+      const PortConfiguration* config, const rtc::ProxyInfo& proxy);
+  void OnConfigWithProxyReady(const PortConfiguration*);
+  void RegisterHttpStart(int port);
+  rtc::Thread* worker_;
+  std::string jid_;
+  std::string session_id_;
+  std::string user_agent_;
+  std::string relay_token_;
+  std::string connection_;
+  rtc::AutoDetectProxy* proxy_detect_;
+  rtc::scoped_ptr<rtc::NetworkManager> network_manager_;
+  rtc::scoped_ptr<rtc::BasicPacketSocketFactory> socket_factory_;
+  rtc::scoped_ptr<HttpPortAllocator> port_allocator_;
+  NicMap nics_;
+  std::vector<Port*> ports_;
+  std::vector<PortAllocatorSession*> sessions_;
+  uint32 timeout_ms_;
+  rtc::SocketAddress stun_address_;
+  rtc::Thread* main_;
+  bool started_;
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_CLIENT_CONNECTIVITYCHECKER_H_
diff --git a/webrtc/p2p/client/connectivitychecker_unittest.cc b/webrtc/p2p/client/connectivitychecker_unittest.cc
new file mode 100644
index 0000000..838dc88
--- /dev/null
+++ b/webrtc/p2p/client/connectivitychecker_unittest.cc
@@ -0,0 +1,375 @@
+/*
+ *  Copyright 2011 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <string>
+
+#include "webrtc/p2p/base/basicpacketsocketfactory.h"
+#include "webrtc/p2p/base/relayport.h"
+#include "webrtc/p2p/base/stunport.h"
+#include "webrtc/p2p/client/connectivitychecker.h"
+#include "webrtc/p2p/client/httpportallocator.h"
+#include "webrtc/base/asynchttprequest.h"
+#include "webrtc/base/fakenetwork.h"
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/socketaddress.h"
+
+namespace cricket {
+
+static const rtc::SocketAddress kClientAddr1("11.11.11.11", 0);
+static const rtc::SocketAddress kClientAddr2("22.22.22.22", 0);
+static const rtc::SocketAddress kExternalAddr("33.33.33.33", 3333);
+static const rtc::SocketAddress kStunAddr("44.44.44.44", 4444);
+static const rtc::SocketAddress kRelayAddr("55.55.55.55", 5555);
+static const rtc::SocketAddress kProxyAddr("66.66.66.66", 6666);
+static const rtc::ProxyType kProxyType = rtc::PROXY_HTTPS;
+static const char kRelayHost[] = "relay.google.com";
+static const char kRelayToken[] =
+    "CAESFwoOb2phQGdvb2dsZS5jb20Q043h47MmGhBTB1rbfIXkhuarDCZe+xF6";
+static const char kBrowserAgent[] = "browser_test";
+static const char kJid[] = "a.b@c";
+static const char kUserName[] = "testuser";
+static const char kPassword[] = "testpassword";
+static const char kMagicCookie[] = "testcookie";
+static const char kRelayUdpPort[] = "4444";
+static const char kRelayTcpPort[] = "5555";
+static const char kRelaySsltcpPort[] = "6666";
+static const char kSessionId[] = "testsession";
+static const char kConnection[] = "testconnection";
+static const int kMinPort = 1000;
+static const int kMaxPort = 2000;
+
+// Fake implementation to mock away real network usage.
+class FakeRelayPort : public RelayPort {
+ public:
+  FakeRelayPort(rtc::Thread* thread,
+                rtc::PacketSocketFactory* factory,
+                rtc::Network* network, const rtc::IPAddress& ip,
+                int min_port, int max_port,
+                const std::string& username, const std::string& password)
+      : RelayPort(thread, factory, network, ip, min_port, max_port,
+                  username, password) {
+  }
+
+  // Just signal that we are done.
+  virtual void PrepareAddress() {
+    SignalPortComplete(this);
+  }
+};
+
+// Fake implementation to mock away real network usage.
+class FakeStunPort : public StunPort {
+ public:
+  FakeStunPort(rtc::Thread* thread,
+               rtc::PacketSocketFactory* factory,
+               rtc::Network* network,
+               const rtc::IPAddress& ip,
+               int min_port, int max_port,
+               const std::string& username, const std::string& password,
+               const ServerAddresses& server_addr)
+      : StunPort(thread, factory, network, ip, min_port, max_port,
+                 username, password, server_addr) {
+  }
+
+  // Just set external address and signal that we are done.
+  virtual void PrepareAddress() {
+    AddAddress(kExternalAddr, kExternalAddr, rtc::SocketAddress(), "udp", "",
+               STUN_PORT_TYPE, ICE_TYPE_PREFERENCE_SRFLX, 0, true);
+    SignalPortComplete(this);
+  }
+};
+
+// Fake implementation to mock away real network usage by responding
+// to http requests immediately.
+class FakeHttpPortAllocatorSession : public TestHttpPortAllocatorSession {
+ public:
+  FakeHttpPortAllocatorSession(
+      HttpPortAllocator* allocator,
+      const std::string& content_name,
+      int component,
+      const std::string& ice_ufrag, const std::string& ice_pwd,
+      const std::vector<rtc::SocketAddress>& stun_hosts,
+      const std::vector<std::string>& relay_hosts,
+      const std::string& relay_token,
+      const std::string& agent)
+      : TestHttpPortAllocatorSession(allocator,
+                                     content_name,
+                                     component,
+                                     ice_ufrag,
+                                     ice_pwd,
+                                     stun_hosts,
+                                     relay_hosts,
+                                     relay_token,
+                                     agent) {
+  }
+  virtual void SendSessionRequest(const std::string& host, int port) {
+    FakeReceiveSessionResponse(host, port);
+  }
+
+  // Pass results to the real implementation.
+  void FakeReceiveSessionResponse(const std::string& host, int port) {
+    rtc::AsyncHttpRequest* response = CreateAsyncHttpResponse(port);
+    TestHttpPortAllocatorSession::OnRequestDone(response);
+    response->Destroy(true);
+  }
+
+ private:
+  // Helper method for creating a response to a relay session request.
+  rtc::AsyncHttpRequest* CreateAsyncHttpResponse(int port) {
+    rtc::AsyncHttpRequest* request =
+        new rtc::AsyncHttpRequest(kBrowserAgent);
+    std::stringstream ss;
+    ss << "username=" << kUserName << std::endl
+       << "password=" << kPassword << std::endl
+       << "magic_cookie=" << kMagicCookie << std::endl
+       << "relay.ip=" << kRelayAddr.ipaddr().ToString() << std::endl
+       << "relay.udp_port=" << kRelayUdpPort << std::endl
+       << "relay.tcp_port=" << kRelayTcpPort << std::endl
+       << "relay.ssltcp_port=" << kRelaySsltcpPort << std::endl;
+    request->response().document.reset(
+        new rtc::MemoryStream(ss.str().c_str()));
+    request->response().set_success();
+    request->set_port(port);
+    request->set_secure(port == rtc::HTTP_SECURE_PORT);
+    return request;
+  }
+};
+
+// Fake implementation for creating fake http sessions.
+class FakeHttpPortAllocator : public HttpPortAllocator {
+ public:
+  FakeHttpPortAllocator(rtc::NetworkManager* network_manager,
+                        const std::string& user_agent)
+      : HttpPortAllocator(network_manager, user_agent) {
+  }
+
+  virtual PortAllocatorSession* CreateSessionInternal(
+      const std::string& content_name, int component,
+      const std::string& ice_ufrag, const std::string& ice_pwd) {
+    std::vector<rtc::SocketAddress> stun_hosts;
+    stun_hosts.push_back(kStunAddr);
+    std::vector<std::string> relay_hosts;
+    relay_hosts.push_back(kRelayHost);
+    return new FakeHttpPortAllocatorSession(this,
+                                            content_name,
+                                            component,
+                                            ice_ufrag,
+                                            ice_pwd,
+                                            stun_hosts,
+                                            relay_hosts,
+                                            kRelayToken,
+                                            kBrowserAgent);
+  }
+};
+
+class ConnectivityCheckerForTest : public ConnectivityChecker {
+ public:
+  ConnectivityCheckerForTest(rtc::Thread* worker,
+                             const std::string& jid,
+                             const std::string& session_id,
+                             const std::string& user_agent,
+                             const std::string& relay_token,
+                             const std::string& connection)
+      : ConnectivityChecker(worker,
+                            jid,
+                            session_id,
+                            user_agent,
+                            relay_token,
+                            connection),
+        proxy_initiated_(false) {
+  }
+
+  rtc::FakeNetworkManager* network_manager() const {
+    return network_manager_;
+  }
+
+  FakeHttpPortAllocator* port_allocator() const {
+    return fake_port_allocator_;
+  }
+
+ protected:
+  // Overridden methods for faking a real network.
+  virtual rtc::NetworkManager* CreateNetworkManager() {
+    network_manager_ = new rtc::FakeNetworkManager();
+    return network_manager_;
+  }
+  virtual rtc::BasicPacketSocketFactory* CreateSocketFactory(
+      rtc::Thread* thread) {
+    // Create socket factory, for simplicity, let it run on the current thread.
+    socket_factory_ =
+        new rtc::BasicPacketSocketFactory(rtc::Thread::Current());
+    return socket_factory_;
+  }
+  virtual HttpPortAllocator* CreatePortAllocator(
+      rtc::NetworkManager* network_manager,
+      const std::string& user_agent,
+      const std::string& relay_token) {
+    fake_port_allocator_ =
+        new FakeHttpPortAllocator(network_manager, user_agent);
+    return fake_port_allocator_;
+  }
+  virtual StunPort* CreateStunPort(
+      const std::string& username, const std::string& password,
+      const PortConfiguration* config, rtc::Network* network) {
+    return new FakeStunPort(worker(),
+                            socket_factory_,
+                            network,
+#ifdef USE_WEBRTC_DEV_BRANCH
+                            network->GetBestIP(),
+#else  // USE_WEBRTC_DEV_BRANCH
+                            network->ip(),
+#endif  // USE_WEBRTC_DEV_BRANCH
+                            kMinPort,
+                            kMaxPort,
+                            username,
+                            password,
+                            config->stun_servers);
+  }
+  virtual RelayPort* CreateRelayPort(
+      const std::string& username, const std::string& password,
+      const PortConfiguration* config, rtc::Network* network) {
+    return new FakeRelayPort(worker(),
+                             socket_factory_,
+                             network,
+#ifdef USE_WEBRTC_DEV_BRANCH
+                             network->GetBestIP(),
+#else  // USE_WEBRTC_DEV_BRANCH
+                             network->ip(),
+#endif  // USE_WEBRTC_DEV_BRANCH
+                             kMinPort,
+                             kMaxPort,
+                             username,
+                             password);
+  }
+  virtual void InitiateProxyDetection() {
+    if (!proxy_initiated_) {
+      proxy_initiated_ = true;
+      proxy_info_.address = kProxyAddr;
+      proxy_info_.type = kProxyType;
+      SetProxyInfo(proxy_info_);
+    }
+  }
+
+  virtual rtc::ProxyInfo GetProxyInfo() const {
+    return proxy_info_;
+  }
+
+ private:
+  rtc::BasicPacketSocketFactory* socket_factory_;
+  FakeHttpPortAllocator* fake_port_allocator_;
+  rtc::FakeNetworkManager* network_manager_;
+  rtc::ProxyInfo proxy_info_;
+  bool proxy_initiated_;
+};
+
+class ConnectivityCheckerTest : public testing::Test {
+ protected:
+  void VerifyNic(const NicInfo& info,
+                 const rtc::SocketAddress& local_address) {
+    // Verify that the external address has been set.
+    EXPECT_EQ(kExternalAddr, info.external_address);
+
+    // Verify that the stun server address has been set.
+    EXPECT_EQ(1U, info.stun_server_addresses.size());
+    EXPECT_EQ(kStunAddr, *(info.stun_server_addresses.begin()));
+
+    // Verify that the media server address has been set. Don't care
+    // about port since it is different for different protocols.
+    EXPECT_EQ(kRelayAddr.ipaddr(), info.media_server_address.ipaddr());
+
+    // Verify that local ip matches.
+    EXPECT_EQ(local_address.ipaddr(), info.ip);
+
+    // Verify that we have received responses for our
+    // pings. Unsuccessful ping has rtt value -1, successful >= 0.
+    EXPECT_GE(info.stun.rtt, 0);
+    EXPECT_GE(info.udp.rtt, 0);
+    EXPECT_GE(info.tcp.rtt, 0);
+    EXPECT_GE(info.ssltcp.rtt, 0);
+
+    // If proxy has been set, verify address and type.
+    if (!info.proxy_info.address.IsNil()) {
+      EXPECT_EQ(kProxyAddr, info.proxy_info.address);
+      EXPECT_EQ(kProxyType, info.proxy_info.type);
+    }
+  }
+};
+
+// Tests a configuration with two network interfaces. Verifies that 4
+// combinations of ip/proxy are created and that all protocols are
+// tested on each combination.
+TEST_F(ConnectivityCheckerTest, TestStart) {
+  ConnectivityCheckerForTest connectivity_checker(rtc::Thread::Current(),
+                                                  kJid,
+                                                  kSessionId,
+                                                  kBrowserAgent,
+                                                  kRelayToken,
+                                                  kConnection);
+  connectivity_checker.Initialize();
+  connectivity_checker.set_stun_address(kStunAddr);
+  connectivity_checker.network_manager()->AddInterface(kClientAddr1);
+  connectivity_checker.network_manager()->AddInterface(kClientAddr2);
+
+  connectivity_checker.Start();
+  rtc::Thread::Current()->ProcessMessages(1000);
+
+  NicMap nics = connectivity_checker.GetResults();
+
+  // There should be 4 nics in our map. 2 for each interface added,
+  // one with proxy set and one without.
+  EXPECT_EQ(4U, nics.size());
+
+  // First verify interfaces without proxy.
+  rtc::SocketAddress nilAddress;
+
+  // First lookup the address of the first nic combined with no proxy.
+  NicMap::iterator i = nics.find(NicId(kClientAddr1.ipaddr(), nilAddress));
+  ASSERT(i != nics.end());
+  NicInfo info = i->second;
+  VerifyNic(info, kClientAddr1);
+
+  // Then make sure the second device has been tested without proxy.
+  i = nics.find(NicId(kClientAddr2.ipaddr(), nilAddress));
+  ASSERT(i != nics.end());
+  info = i->second;
+  VerifyNic(info, kClientAddr2);
+
+  // Now verify both interfaces with proxy.
+  i = nics.find(NicId(kClientAddr1.ipaddr(), kProxyAddr));
+  ASSERT(i != nics.end());
+  info = i->second;
+  VerifyNic(info, kClientAddr1);
+
+  i = nics.find(NicId(kClientAddr2.ipaddr(), kProxyAddr));
+  ASSERT(i != nics.end());
+  info = i->second;
+  VerifyNic(info, kClientAddr2);
+};
+
+// Tests that nothing bad happens if thera are no network interfaces
+// available to check.
+TEST_F(ConnectivityCheckerTest, TestStartNoNetwork) {
+  ConnectivityCheckerForTest connectivity_checker(rtc::Thread::Current(),
+                                                  kJid,
+                                                  kSessionId,
+                                                  kBrowserAgent,
+                                                  kRelayToken,
+                                                  kConnection);
+  connectivity_checker.Initialize();
+  connectivity_checker.Start();
+  rtc::Thread::Current()->ProcessMessages(1000);
+
+  NicMap nics = connectivity_checker.GetResults();
+
+  // Verify that no nics where checked.
+  EXPECT_EQ(0U, nics.size());
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/client/fakeportallocator.h b/webrtc/p2p/client/fakeportallocator.h
new file mode 100644
index 0000000..73dae3a
--- /dev/null
+++ b/webrtc/p2p/client/fakeportallocator.h
@@ -0,0 +1,121 @@
+/*
+ *  Copyright 2010 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_CLIENT_FAKEPORTALLOCATOR_H_
+#define WEBRTC_P2P_CLIENT_FAKEPORTALLOCATOR_H_
+
+#include <string>
+#include "webrtc/p2p/base/basicpacketsocketfactory.h"
+#include "webrtc/p2p/base/portallocator.h"
+#include "webrtc/p2p/base/udpport.h"
+#include "webrtc/base/scoped_ptr.h"
+
+namespace rtc {
+class SocketFactory;
+class Thread;
+}
+
+namespace cricket {
+
+class FakePortAllocatorSession : public PortAllocatorSession {
+ public:
+  FakePortAllocatorSession(rtc::Thread* worker_thread,
+                           rtc::PacketSocketFactory* factory,
+                           const std::string& content_name,
+                           int component,
+                           const std::string& ice_ufrag,
+                           const std::string& ice_pwd)
+      : PortAllocatorSession(content_name, component, ice_ufrag, ice_pwd,
+                             cricket::PORTALLOCATOR_ENABLE_SHARED_UFRAG),
+        worker_thread_(worker_thread),
+        factory_(factory),
+        network_("network", "unittest",
+                 rtc::IPAddress(INADDR_LOOPBACK), 8),
+        port_(), running_(false),
+        port_config_count_(0) {
+    network_.AddIP(rtc::IPAddress(INADDR_LOOPBACK));
+  }
+
+  virtual void StartGettingPorts() {
+    if (!port_) {
+      port_.reset(cricket::UDPPort::Create(worker_thread_,
+                                           factory_,
+                                           &network_,
+#ifdef USE_WEBRTC_DEV_BRANCH
+                                           network_.GetBestIP(),
+#else  // USE_WEBRTC_DEV_BRANCH
+                                           network_.ip(),
+#endif  // USE_WEBRTC_DEV_BRANCH
+                                           0,
+                                           0,
+                                           username(),
+                                           password()));
+      AddPort(port_.get());
+    }
+    ++port_config_count_;
+    running_ = true;
+  }
+
+  virtual void StopGettingPorts() { running_ = false; }
+  virtual bool IsGettingPorts() { return running_; }
+  int port_config_count() { return port_config_count_; }
+
+  void AddPort(cricket::Port* port) {
+    port->set_component(component_);
+    port->set_generation(0);
+    port->SignalPortComplete.connect(
+        this, &FakePortAllocatorSession::OnPortComplete);
+    port->PrepareAddress();
+    SignalPortReady(this, port);
+  }
+  void OnPortComplete(cricket::Port* port) {
+    SignalCandidatesReady(this, port->Candidates());
+    SignalCandidatesAllocationDone(this);
+  }
+
+ private:
+  rtc::Thread* worker_thread_;
+  rtc::PacketSocketFactory* factory_;
+  rtc::Network network_;
+  rtc::scoped_ptr<cricket::Port> port_;
+  bool running_;
+  int port_config_count_;
+};
+
+class FakePortAllocator : public cricket::PortAllocator {
+ public:
+  FakePortAllocator(rtc::Thread* worker_thread,
+                    rtc::PacketSocketFactory* factory)
+      : worker_thread_(worker_thread), factory_(factory) {
+    if (factory_ == NULL) {
+      owned_factory_.reset(new rtc::BasicPacketSocketFactory(
+          worker_thread_));
+      factory_ = owned_factory_.get();
+    }
+  }
+
+  virtual cricket::PortAllocatorSession* CreateSessionInternal(
+      const std::string& content_name,
+      int component,
+      const std::string& ice_ufrag,
+      const std::string& ice_pwd) {
+    return new FakePortAllocatorSession(
+        worker_thread_, factory_, content_name, component, ice_ufrag, ice_pwd);
+  }
+
+ private:
+  rtc::Thread* worker_thread_;
+  rtc::PacketSocketFactory* factory_;
+  rtc::scoped_ptr<rtc::BasicPacketSocketFactory> owned_factory_;
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_CLIENT_FAKEPORTALLOCATOR_H_
diff --git a/webrtc/p2p/client/httpportallocator.cc b/webrtc/p2p/client/httpportallocator.cc
new file mode 100644
index 0000000..c072da2
--- /dev/null
+++ b/webrtc/p2p/client/httpportallocator.cc
@@ -0,0 +1,326 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/client/httpportallocator.h"
+
+#include <algorithm>
+#include <map>
+
+#include "webrtc/base/asynchttprequest.h"
+#include "webrtc/base/basicdefs.h"
+#include "webrtc/base/common.h"
+#include "webrtc/base/helpers.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/nethelpers.h"
+#include "webrtc/base/signalthread.h"
+#include "webrtc/base/stringencode.h"
+
+namespace {
+
+// Helper routine to remove whitespace from the ends of a string.
+void Trim(std::string& str) {
+  size_t first = str.find_first_not_of(" \t\r\n");
+  if (first == std::string::npos) {
+    str.clear();
+    return;
+  }
+
+  ASSERT(str.find_last_not_of(" \t\r\n") != std::string::npos);
+}
+
+// Parses the lines in the result of the HTTP request that are of the form
+// 'a=b' and returns them in a map.
+typedef std::map<std::string, std::string> StringMap;
+void ParseMap(const std::string& string, StringMap& map) {
+  size_t start_of_line = 0;
+  size_t end_of_line = 0;
+
+  for (;;) {  // for each line
+    start_of_line = string.find_first_not_of("\r\n", end_of_line);
+    if (start_of_line == std::string::npos)
+      break;
+
+    end_of_line = string.find_first_of("\r\n", start_of_line);
+    if (end_of_line == std::string::npos) {
+      end_of_line = string.length();
+    }
+
+    size_t equals = string.find('=', start_of_line);
+    if ((equals >= end_of_line) || (equals == std::string::npos))
+      continue;
+
+    std::string key(string, start_of_line, equals - start_of_line);
+    std::string value(string, equals + 1, end_of_line - equals - 1);
+
+    Trim(key);
+    Trim(value);
+
+    if ((key.size() > 0) && (value.size() > 0))
+      map[key] = value;
+  }
+}
+
+}  // namespace
+
+namespace cricket {
+
+// HttpPortAllocatorBase
+
+const int HttpPortAllocatorBase::kNumRetries = 5;
+
+const char HttpPortAllocatorBase::kCreateSessionURL[] = "/create_session";
+
+HttpPortAllocatorBase::HttpPortAllocatorBase(
+    rtc::NetworkManager* network_manager,
+    rtc::PacketSocketFactory* socket_factory,
+    const std::string &user_agent)
+    : BasicPortAllocator(network_manager, socket_factory), agent_(user_agent) {
+  relay_hosts_.push_back("relay.google.com");
+  stun_hosts_.push_back(
+      rtc::SocketAddress("stun.l.google.com", 19302));
+}
+
+HttpPortAllocatorBase::HttpPortAllocatorBase(
+    rtc::NetworkManager* network_manager,
+    const std::string &user_agent)
+    : BasicPortAllocator(network_manager), agent_(user_agent) {
+  relay_hosts_.push_back("relay.google.com");
+  stun_hosts_.push_back(
+      rtc::SocketAddress("stun.l.google.com", 19302));
+}
+
+HttpPortAllocatorBase::~HttpPortAllocatorBase() {
+}
+
+// HttpPortAllocatorSessionBase
+
+HttpPortAllocatorSessionBase::HttpPortAllocatorSessionBase(
+    HttpPortAllocatorBase* allocator,
+    const std::string& content_name,
+    int component,
+    const std::string& ice_ufrag,
+    const std::string& ice_pwd,
+    const std::vector<rtc::SocketAddress>& stun_hosts,
+    const std::vector<std::string>& relay_hosts,
+    const std::string& relay_token,
+    const std::string& user_agent)
+    : BasicPortAllocatorSession(allocator, content_name, component,
+                                ice_ufrag, ice_pwd),
+      relay_hosts_(relay_hosts), stun_hosts_(stun_hosts),
+      relay_token_(relay_token), agent_(user_agent), attempts_(0) {
+}
+
+HttpPortAllocatorSessionBase::~HttpPortAllocatorSessionBase() {}
+
+void HttpPortAllocatorSessionBase::GetPortConfigurations() {
+  // Creating relay sessions can take time and is done asynchronously.
+  // Creating stun sessions could also take time and could be done aysnc also,
+  // but for now is done here and added to the initial config.  Note any later
+  // configs will have unresolved stun ips and will be discarded by the
+  // AllocationSequence.
+  ServerAddresses hosts;
+  for (std::vector<rtc::SocketAddress>::iterator it = stun_hosts_.begin();
+      it != stun_hosts_.end(); ++it) {
+    hosts.insert(*it);
+  }
+
+  PortConfiguration* config = new PortConfiguration(hosts,
+                                                    username(),
+                                                    password());
+  ConfigReady(config);
+  TryCreateRelaySession();
+}
+
+void HttpPortAllocatorSessionBase::TryCreateRelaySession() {
+  if (allocator()->flags() & PORTALLOCATOR_DISABLE_RELAY) {
+    LOG(LS_VERBOSE) << "HttpPortAllocator: Relay ports disabled, skipping.";
+    return;
+  }
+
+  if (attempts_ == HttpPortAllocator::kNumRetries) {
+    LOG(LS_ERROR) << "HttpPortAllocator: maximum number of requests reached; "
+                  << "giving up on relay.";
+    return;
+  }
+
+  if (relay_hosts_.size() == 0) {
+    LOG(LS_ERROR) << "HttpPortAllocator: no relay hosts configured.";
+    return;
+  }
+
+  // Choose the next host to try.
+  std::string host = relay_hosts_[attempts_ % relay_hosts_.size()];
+  attempts_++;
+  LOG(LS_INFO) << "HTTPPortAllocator: sending to relay host " << host;
+  if (relay_token_.empty()) {
+    LOG(LS_WARNING) << "No relay auth token found.";
+  }
+
+  SendSessionRequest(host, rtc::HTTP_SECURE_PORT);
+}
+
+std::string HttpPortAllocatorSessionBase::GetSessionRequestUrl() {
+  std::string url = std::string(HttpPortAllocator::kCreateSessionURL);
+  if (allocator()->flags() & PORTALLOCATOR_ENABLE_SHARED_UFRAG) {
+    ASSERT(!username().empty());
+    ASSERT(!password().empty());
+    url = url + "?username=" + rtc::s_url_encode(username()) +
+        "&password=" + rtc::s_url_encode(password());
+  }
+  return url;
+}
+
+void HttpPortAllocatorSessionBase::ReceiveSessionResponse(
+    const std::string& response) {
+
+  StringMap map;
+  ParseMap(response, map);
+
+  if (!username().empty() && map["username"] != username()) {
+    LOG(LS_WARNING) << "Received unexpected username value from relay server.";
+  }
+  if (!password().empty() && map["password"] != password()) {
+    LOG(LS_WARNING) << "Received unexpected password value from relay server.";
+  }
+
+  std::string relay_ip = map["relay.ip"];
+  std::string relay_udp_port = map["relay.udp_port"];
+  std::string relay_tcp_port = map["relay.tcp_port"];
+  std::string relay_ssltcp_port = map["relay.ssltcp_port"];
+
+  ServerAddresses hosts;
+  for (std::vector<rtc::SocketAddress>::iterator it = stun_hosts_.begin();
+      it != stun_hosts_.end(); ++it) {
+    hosts.insert(*it);
+  }
+
+  PortConfiguration* config = new PortConfiguration(hosts,
+                                                    map["username"],
+                                                    map["password"]);
+
+  RelayServerConfig relay_config(RELAY_GTURN);
+  if (!relay_udp_port.empty()) {
+    rtc::SocketAddress address(relay_ip, atoi(relay_udp_port.c_str()));
+    relay_config.ports.push_back(ProtocolAddress(address, PROTO_UDP));
+  }
+  if (!relay_tcp_port.empty()) {
+    rtc::SocketAddress address(relay_ip, atoi(relay_tcp_port.c_str()));
+    relay_config.ports.push_back(ProtocolAddress(address, PROTO_TCP));
+  }
+  if (!relay_ssltcp_port.empty()) {
+    rtc::SocketAddress address(relay_ip, atoi(relay_ssltcp_port.c_str()));
+    relay_config.ports.push_back(ProtocolAddress(address, PROTO_SSLTCP));
+  }
+  config->AddRelay(relay_config);
+  ConfigReady(config);
+}
+
+// HttpPortAllocator
+
+HttpPortAllocator::HttpPortAllocator(
+    rtc::NetworkManager* network_manager,
+    rtc::PacketSocketFactory* socket_factory,
+    const std::string &user_agent)
+    : HttpPortAllocatorBase(network_manager, socket_factory, user_agent) {
+}
+
+HttpPortAllocator::HttpPortAllocator(
+    rtc::NetworkManager* network_manager,
+    const std::string &user_agent)
+    : HttpPortAllocatorBase(network_manager, user_agent) {
+}
+HttpPortAllocator::~HttpPortAllocator() {}
+
+PortAllocatorSession* HttpPortAllocator::CreateSessionInternal(
+    const std::string& content_name,
+    int component,
+    const std::string& ice_ufrag, const std::string& ice_pwd) {
+  return new HttpPortAllocatorSession(this, content_name, component,
+                                      ice_ufrag, ice_pwd, stun_hosts(),
+                                      relay_hosts(), relay_token(),
+                                      user_agent());
+}
+
+// HttpPortAllocatorSession
+
+HttpPortAllocatorSession::HttpPortAllocatorSession(
+    HttpPortAllocator* allocator,
+    const std::string& content_name,
+    int component,
+    const std::string& ice_ufrag,
+    const std::string& ice_pwd,
+    const std::vector<rtc::SocketAddress>& stun_hosts,
+    const std::vector<std::string>& relay_hosts,
+    const std::string& relay,
+    const std::string& agent)
+    : HttpPortAllocatorSessionBase(allocator, content_name, component,
+                                   ice_ufrag, ice_pwd, stun_hosts,
+                                   relay_hosts, relay, agent) {
+}
+
+HttpPortAllocatorSession::~HttpPortAllocatorSession() {
+  for (std::list<rtc::AsyncHttpRequest*>::iterator it = requests_.begin();
+       it != requests_.end(); ++it) {
+    (*it)->Destroy(true);
+  }
+}
+
+void HttpPortAllocatorSession::SendSessionRequest(const std::string& host,
+                                                  int port) {
+  // Initiate an HTTP request to create a session through the chosen host.
+  rtc::AsyncHttpRequest* request =
+      new rtc::AsyncHttpRequest(user_agent());
+  request->SignalWorkDone.connect(this,
+      &HttpPortAllocatorSession::OnRequestDone);
+
+  request->set_secure(port == rtc::HTTP_SECURE_PORT);
+  request->set_proxy(allocator()->proxy());
+  request->response().document.reset(new rtc::MemoryStream);
+  request->request().verb = rtc::HV_GET;
+  request->request().path = GetSessionRequestUrl();
+  request->request().addHeader("X-Talk-Google-Relay-Auth", relay_token(), true);
+  request->request().addHeader("X-Stream-Type", "video_rtp", true);
+  request->set_host(host);
+  request->set_port(port);
+  request->Start();
+  request->Release();
+
+  requests_.push_back(request);
+}
+
+void HttpPortAllocatorSession::OnRequestDone(rtc::SignalThread* data) {
+  rtc::AsyncHttpRequest* request =
+      static_cast<rtc::AsyncHttpRequest*>(data);
+
+  // Remove the request from the list of active requests.
+  std::list<rtc::AsyncHttpRequest*>::iterator it =
+      std::find(requests_.begin(), requests_.end(), request);
+  if (it != requests_.end()) {
+    requests_.erase(it);
+  }
+
+  if (request->response().scode != 200) {
+    LOG(LS_WARNING) << "HTTPPortAllocator: request "
+                    << " received error " << request->response().scode;
+    TryCreateRelaySession();
+    return;
+  }
+  LOG(LS_INFO) << "HTTPPortAllocator: request succeeded";
+
+  rtc::MemoryStream* stream =
+      static_cast<rtc::MemoryStream*>(request->response().document.get());
+  stream->Rewind();
+  size_t length;
+  stream->GetSize(&length);
+  std::string resp = std::string(stream->GetBuffer(), length);
+  ReceiveSessionResponse(resp);
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/client/httpportallocator.h b/webrtc/p2p/client/httpportallocator.h
new file mode 100644
index 0000000..e2fa743
--- /dev/null
+++ b/webrtc/p2p/client/httpportallocator.h
@@ -0,0 +1,173 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_CLIENT_HTTPPORTALLOCATOR_H_
+#define WEBRTC_P2P_CLIENT_HTTPPORTALLOCATOR_H_
+
+#include <list>
+#include <string>
+#include <vector>
+
+#include "webrtc/p2p/client/basicportallocator.h"
+
+class HttpPortAllocatorTest_TestSessionRequestUrl_Test;
+
+namespace rtc {
+class AsyncHttpRequest;
+class SignalThread;
+}
+
+namespace cricket {
+
+class HttpPortAllocatorBase : public BasicPortAllocator {
+ public:
+  // The number of HTTP requests we should attempt before giving up.
+  static const int kNumRetries;
+
+  // Records the URL that we will GET in order to create a session.
+  static const char kCreateSessionURL[];
+
+  HttpPortAllocatorBase(rtc::NetworkManager* network_manager,
+                        const std::string& user_agent);
+  HttpPortAllocatorBase(rtc::NetworkManager* network_manager,
+                        rtc::PacketSocketFactory* socket_factory,
+                        const std::string& user_agent);
+  virtual ~HttpPortAllocatorBase();
+
+  // CreateSession is defined in BasicPortAllocator but is
+  // redefined here as pure virtual.
+  virtual PortAllocatorSession* CreateSessionInternal(
+      const std::string& content_name,
+      int component,
+      const std::string& ice_ufrag,
+      const std::string& ice_pwd) = 0;
+
+  void SetStunHosts(const std::vector<rtc::SocketAddress>& hosts) {
+    if (!hosts.empty()) {
+      stun_hosts_ = hosts;
+    }
+  }
+  void SetRelayHosts(const std::vector<std::string>& hosts) {
+    if (!hosts.empty()) {
+      relay_hosts_ = hosts;
+    }
+  }
+  void SetRelayToken(const std::string& relay) { relay_token_ = relay; }
+
+  const std::vector<rtc::SocketAddress>& stun_hosts() const {
+    return stun_hosts_;
+  }
+
+  const std::vector<std::string>& relay_hosts() const {
+    return relay_hosts_;
+  }
+
+  const std::string& relay_token() const {
+    return relay_token_;
+  }
+
+  const std::string& user_agent() const {
+    return agent_;
+  }
+
+ private:
+  std::vector<rtc::SocketAddress> stun_hosts_;
+  std::vector<std::string> relay_hosts_;
+  std::string relay_token_;
+  std::string agent_;
+};
+
+class RequestData;
+
+class HttpPortAllocatorSessionBase : public BasicPortAllocatorSession {
+ public:
+  HttpPortAllocatorSessionBase(
+      HttpPortAllocatorBase* allocator,
+      const std::string& content_name,
+      int component,
+      const std::string& ice_ufrag,
+      const std::string& ice_pwd,
+      const std::vector<rtc::SocketAddress>& stun_hosts,
+      const std::vector<std::string>& relay_hosts,
+      const std::string& relay,
+      const std::string& agent);
+  virtual ~HttpPortAllocatorSessionBase();
+
+  const std::string& relay_token() const {
+    return relay_token_;
+  }
+
+  const std::string& user_agent() const {
+      return agent_;
+  }
+
+  virtual void SendSessionRequest(const std::string& host, int port) = 0;
+  virtual void ReceiveSessionResponse(const std::string& response);
+
+  // Made public for testing. Should be protected.
+  std::string GetSessionRequestUrl();
+
+ protected:
+  virtual void GetPortConfigurations();
+  void TryCreateRelaySession();
+  virtual HttpPortAllocatorBase* allocator() {
+    return static_cast<HttpPortAllocatorBase*>(
+        BasicPortAllocatorSession::allocator());
+  }
+
+ private:
+  std::vector<std::string> relay_hosts_;
+  std::vector<rtc::SocketAddress> stun_hosts_;
+  std::string relay_token_;
+  std::string agent_;
+  int attempts_;
+};
+
+class HttpPortAllocator : public HttpPortAllocatorBase {
+ public:
+  HttpPortAllocator(rtc::NetworkManager* network_manager,
+                    const std::string& user_agent);
+  HttpPortAllocator(rtc::NetworkManager* network_manager,
+                    rtc::PacketSocketFactory* socket_factory,
+                    const std::string& user_agent);
+  virtual ~HttpPortAllocator();
+  virtual PortAllocatorSession* CreateSessionInternal(
+      const std::string& content_name,
+      int component,
+      const std::string& ice_ufrag, const std::string& ice_pwd);
+};
+
+class HttpPortAllocatorSession : public HttpPortAllocatorSessionBase {
+ public:
+  HttpPortAllocatorSession(
+      HttpPortAllocator* allocator,
+      const std::string& content_name,
+      int component,
+      const std::string& ice_ufrag,
+      const std::string& ice_pwd,
+      const std::vector<rtc::SocketAddress>& stun_hosts,
+      const std::vector<std::string>& relay_hosts,
+      const std::string& relay,
+      const std::string& agent);
+  virtual ~HttpPortAllocatorSession();
+
+  virtual void SendSessionRequest(const std::string& host, int port);
+
+ protected:
+  // Protected for diagnostics.
+  virtual void OnRequestDone(rtc::SignalThread* request);
+
+ private:
+  std::list<rtc::AsyncHttpRequest*> requests_;
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_CLIENT_HTTPPORTALLOCATOR_H_
diff --git a/webrtc/p2p/client/portallocator_unittest.cc b/webrtc/p2p/client/portallocator_unittest.cc
new file mode 100644
index 0000000..5dcc8f9
--- /dev/null
+++ b/webrtc/p2p/client/portallocator_unittest.cc
@@ -0,0 +1,1066 @@
+/*
+ *  Copyright 2009 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/base/basicpacketsocketfactory.h"
+#include "webrtc/p2p/base/constants.h"
+#include "webrtc/p2p/base/p2ptransportchannel.h"
+#include "webrtc/p2p/base/portallocatorsessionproxy.h"
+#include "webrtc/p2p/base/testrelayserver.h"
+#include "webrtc/p2p/base/teststunserver.h"
+#include "webrtc/p2p/base/testturnserver.h"
+#include "webrtc/p2p/client/basicportallocator.h"
+#include "webrtc/p2p/client/httpportallocator.h"
+#include "webrtc/base/fakenetwork.h"
+#include "webrtc/base/firewallsocketserver.h"
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/helpers.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/base/natserver.h"
+#include "webrtc/base/natsocketfactory.h"
+#include "webrtc/base/network.h"
+#include "webrtc/base/physicalsocketserver.h"
+#include "webrtc/base/socketaddress.h"
+#include "webrtc/base/ssladapter.h"
+#include "webrtc/base/thread.h"
+#include "webrtc/base/virtualsocketserver.h"
+
+using cricket::ServerAddresses;
+using rtc::SocketAddress;
+using rtc::Thread;
+
+static const SocketAddress kClientAddr("11.11.11.11", 0);
+static const SocketAddress kPrivateAddr("192.168.1.11", 0);
+static const SocketAddress kClientIPv6Addr(
+    "2401:fa00:4:1000:be30:5bff:fee5:c3", 0);
+static const SocketAddress kClientAddr2("22.22.22.22", 0);
+static const SocketAddress kNatAddr("77.77.77.77", rtc::NAT_SERVER_PORT);
+static const SocketAddress kRemoteClientAddr("22.22.22.22", 0);
+static const SocketAddress kStunAddr("99.99.99.1", cricket::STUN_SERVER_PORT);
+static const SocketAddress kRelayUdpIntAddr("99.99.99.2", 5000);
+static const SocketAddress kRelayUdpExtAddr("99.99.99.3", 5001);
+static const SocketAddress kRelayTcpIntAddr("99.99.99.2", 5002);
+static const SocketAddress kRelayTcpExtAddr("99.99.99.3", 5003);
+static const SocketAddress kRelaySslTcpIntAddr("99.99.99.2", 5004);
+static const SocketAddress kRelaySslTcpExtAddr("99.99.99.3", 5005);
+static const SocketAddress kTurnUdpIntAddr("99.99.99.4", 3478);
+static const SocketAddress kTurnTcpIntAddr("99.99.99.5", 3478);
+static const SocketAddress kTurnUdpExtAddr("99.99.99.6", 0);
+
+// Minimum and maximum port for port range tests.
+static const int kMinPort = 10000;
+static const int kMaxPort = 10099;
+
+// Based on ICE_UFRAG_LENGTH
+static const char kIceUfrag0[] = "TESTICEUFRAG0000";
+// Based on ICE_PWD_LENGTH
+static const char kIcePwd0[] = "TESTICEPWD00000000000000";
+
+static const char kContentName[] = "test content";
+
+static const int kDefaultAllocationTimeout = 1000;
+static const char kTurnUsername[] = "test";
+static const char kTurnPassword[] = "test";
+
+namespace cricket {
+
+// Helper for dumping candidates
+std::ostream& operator<<(std::ostream& os, const cricket::Candidate& c) {
+  os << c.ToString();
+  return os;
+}
+
+}  // namespace cricket
+
+class PortAllocatorTest : public testing::Test, public sigslot::has_slots<> {
+ public:
+  PortAllocatorTest()
+      : pss_(new rtc::PhysicalSocketServer),
+        vss_(new rtc::VirtualSocketServer(pss_.get())),
+        fss_(new rtc::FirewallSocketServer(vss_.get())),
+        ss_scope_(fss_.get()),
+        nat_factory_(vss_.get(), kNatAddr),
+        nat_socket_factory_(&nat_factory_),
+        stun_server_(cricket::TestStunServer::Create(Thread::Current(),
+                                                     kStunAddr)),
+        relay_server_(Thread::Current(), kRelayUdpIntAddr, kRelayUdpExtAddr,
+                      kRelayTcpIntAddr, kRelayTcpExtAddr,
+                      kRelaySslTcpIntAddr, kRelaySslTcpExtAddr),
+        turn_server_(Thread::Current(), kTurnUdpIntAddr, kTurnUdpExtAddr),
+        candidate_allocation_done_(false) {
+    cricket::ServerAddresses stun_servers;
+    stun_servers.insert(kStunAddr);
+    // Passing the addresses of GTURN servers will enable GTURN in
+    // Basicportallocator.
+    allocator_.reset(new cricket::BasicPortAllocator(
+        &network_manager_,
+        stun_servers,
+        kRelayUdpIntAddr, kRelayTcpIntAddr, kRelaySslTcpIntAddr));
+    allocator_->set_step_delay(cricket::kMinimumStepDelay);
+  }
+
+  void AddInterface(const SocketAddress& addr) {
+    network_manager_.AddInterface(addr);
+  }
+  bool SetPortRange(int min_port, int max_port) {
+    return allocator_->SetPortRange(min_port, max_port);
+  }
+  void ResetWithNatServer(const rtc::SocketAddress& stun_server) {
+    nat_server_.reset(new rtc::NATServer(
+        rtc::NAT_OPEN_CONE, vss_.get(), kNatAddr, vss_.get(), kNatAddr));
+
+    ServerAddresses stun_servers;
+    stun_servers.insert(stun_server);
+    allocator_.reset(new cricket::BasicPortAllocator(
+        &network_manager_, &nat_socket_factory_, stun_servers));
+    allocator().set_step_delay(cricket::kMinimumStepDelay);
+  }
+
+  // Create a BasicPortAllocator without GTURN and add the TURN servers.
+  void ResetWithTurnServers(const rtc::SocketAddress& udp_turn,
+                            const rtc::SocketAddress& tcp_turn) {
+    allocator_.reset(new cricket::BasicPortAllocator(&network_manager_));
+    allocator().set_step_delay(cricket::kMinimumStepDelay);
+    AddTurnServers(udp_turn, tcp_turn);
+  }
+
+  void AddTurnServers(const rtc::SocketAddress& udp_turn,
+                      const rtc::SocketAddress& tcp_turn) {
+    cricket::RelayServerConfig relay_server(cricket::RELAY_TURN);
+    cricket::RelayCredentials credentials(kTurnUsername, kTurnPassword);
+    relay_server.credentials = credentials;
+
+    if (!udp_turn.IsNil()) {
+      relay_server.ports.push_back(cricket::ProtocolAddress(
+          kTurnUdpIntAddr, cricket::PROTO_UDP, false));
+    }
+    if (!tcp_turn.IsNil()) {
+      relay_server.ports.push_back(cricket::ProtocolAddress(
+          kTurnTcpIntAddr, cricket::PROTO_TCP, false));
+    }
+    allocator_->AddRelay(relay_server);
+  }
+
+  bool CreateSession(int component) {
+    session_.reset(CreateSession("session", component));
+    if (!session_)
+      return false;
+    return true;
+  }
+
+  bool CreateSession(int component, const std::string& content_name) {
+    session_.reset(CreateSession("session", content_name, component));
+    if (!session_)
+      return false;
+    return true;
+  }
+
+  cricket::PortAllocatorSession* CreateSession(
+      const std::string& sid, int component) {
+    return CreateSession(sid, kContentName, component);
+  }
+
+  cricket::PortAllocatorSession* CreateSession(
+      const std::string& sid, const std::string& content_name, int component) {
+    return CreateSession(sid, content_name, component, kIceUfrag0, kIcePwd0);
+  }
+
+  cricket::PortAllocatorSession* CreateSession(
+      const std::string& sid, const std::string& content_name, int component,
+      const std::string& ice_ufrag, const std::string& ice_pwd) {
+    cricket::PortAllocatorSession* session =
+        allocator_->CreateSession(
+            sid, content_name, component, ice_ufrag, ice_pwd);
+    session->SignalPortReady.connect(this,
+            &PortAllocatorTest::OnPortReady);
+    session->SignalCandidatesReady.connect(this,
+        &PortAllocatorTest::OnCandidatesReady);
+    session->SignalCandidatesAllocationDone.connect(this,
+        &PortAllocatorTest::OnCandidatesAllocationDone);
+    return session;
+  }
+
+  static bool CheckCandidate(const cricket::Candidate& c,
+                             int component, const std::string& type,
+                             const std::string& proto,
+                             const SocketAddress& addr) {
+    return (c.component() == component && c.type() == type &&
+        c.protocol() == proto && c.address().ipaddr() == addr.ipaddr() &&
+        ((addr.port() == 0 && (c.address().port() != 0)) ||
+        (c.address().port() == addr.port())));
+  }
+  static bool CheckPort(const rtc::SocketAddress& addr,
+                        int min_port, int max_port) {
+    return (addr.port() >= min_port && addr.port() <= max_port);
+  }
+
+  void OnCandidatesAllocationDone(cricket::PortAllocatorSession* session) {
+    // We should only get this callback once, except in the mux test where
+    // we have multiple port allocation sessions.
+    if (session == session_.get()) {
+      ASSERT_FALSE(candidate_allocation_done_);
+      candidate_allocation_done_ = true;
+    }
+  }
+
+  // Check if all ports allocated have send-buffer size |expected|. If
+  // |expected| == -1, check if GetOptions returns SOCKET_ERROR.
+  void CheckSendBufferSizesOfAllPorts(int expected) {
+    std::vector<cricket::PortInterface*>::iterator it;
+    for (it = ports_.begin(); it < ports_.end(); ++it) {
+      int send_buffer_size;
+      if (expected == -1) {
+        EXPECT_EQ(SOCKET_ERROR,
+                  (*it)->GetOption(rtc::Socket::OPT_SNDBUF,
+                                   &send_buffer_size));
+      } else {
+        EXPECT_EQ(0, (*it)->GetOption(rtc::Socket::OPT_SNDBUF,
+                                      &send_buffer_size));
+        ASSERT_EQ(expected, send_buffer_size);
+      }
+    }
+  }
+
+ protected:
+  cricket::BasicPortAllocator& allocator() {
+    return *allocator_;
+  }
+
+  void OnPortReady(cricket::PortAllocatorSession* ses,
+                   cricket::PortInterface* port) {
+    LOG(LS_INFO) << "OnPortReady: " << port->ToString();
+    ports_.push_back(port);
+  }
+  void OnCandidatesReady(cricket::PortAllocatorSession* ses,
+                         const std::vector<cricket::Candidate>& candidates) {
+    for (size_t i = 0; i < candidates.size(); ++i) {
+      LOG(LS_INFO) << "OnCandidatesReady: " << candidates[i].ToString();
+      candidates_.push_back(candidates[i]);
+    }
+  }
+
+  bool HasRelayAddress(const cricket::ProtocolAddress& proto_addr) {
+    for (size_t i = 0; i < allocator_->relays().size(); ++i) {
+      cricket::RelayServerConfig server_config = allocator_->relays()[i];
+      cricket::PortList::const_iterator relay_port;
+      for (relay_port = server_config.ports.begin();
+          relay_port != server_config.ports.end(); ++relay_port) {
+        if (proto_addr.address == relay_port->address &&
+            proto_addr.proto == relay_port->proto)
+          return true;
+      }
+    }
+    return false;
+  }
+
+  rtc::scoped_ptr<rtc::PhysicalSocketServer> pss_;
+  rtc::scoped_ptr<rtc::VirtualSocketServer> vss_;
+  rtc::scoped_ptr<rtc::FirewallSocketServer> fss_;
+  rtc::SocketServerScope ss_scope_;
+  rtc::scoped_ptr<rtc::NATServer> nat_server_;
+  rtc::NATSocketFactory nat_factory_;
+  rtc::BasicPacketSocketFactory nat_socket_factory_;
+  rtc::scoped_ptr<cricket::TestStunServer> stun_server_;
+  cricket::TestRelayServer relay_server_;
+  cricket::TestTurnServer turn_server_;
+  rtc::FakeNetworkManager network_manager_;
+  rtc::scoped_ptr<cricket::BasicPortAllocator> allocator_;
+  rtc::scoped_ptr<cricket::PortAllocatorSession> session_;
+  std::vector<cricket::PortInterface*> ports_;
+  std::vector<cricket::Candidate> candidates_;
+  bool candidate_allocation_done_;
+};
+
+// Tests that we can init the port allocator and create a session.
+TEST_F(PortAllocatorTest, TestBasic) {
+  EXPECT_EQ(&network_manager_, allocator().network_manager());
+  EXPECT_EQ(kStunAddr, *allocator().stun_servers().begin());
+  ASSERT_EQ(1u, allocator().relays().size());
+  EXPECT_EQ(cricket::RELAY_GTURN, allocator().relays()[0].type);
+  // Empty relay credentials are used for GTURN.
+  EXPECT_TRUE(allocator().relays()[0].credentials.username.empty());
+  EXPECT_TRUE(allocator().relays()[0].credentials.password.empty());
+  EXPECT_TRUE(HasRelayAddress(cricket::ProtocolAddress(
+      kRelayUdpIntAddr, cricket::PROTO_UDP)));
+  EXPECT_TRUE(HasRelayAddress(cricket::ProtocolAddress(
+      kRelayTcpIntAddr, cricket::PROTO_TCP)));
+  EXPECT_TRUE(HasRelayAddress(cricket::ProtocolAddress(
+      kRelaySslTcpIntAddr, cricket::PROTO_SSLTCP)));
+  EXPECT_TRUE(CreateSession(cricket::ICE_CANDIDATE_COMPONENT_RTP));
+}
+
+// Tests that we allocator session not trying to allocate ports for every 250ms.
+TEST_F(PortAllocatorTest, TestNoNetworkInterface) {
+  EXPECT_TRUE(CreateSession(cricket::ICE_CANDIDATE_COMPONENT_RTP));
+  session_->StartGettingPorts();
+  // Waiting for one second to make sure BasicPortAllocatorSession has not
+  // called OnAllocate multiple times. In old behavior it's called every 250ms.
+  // When there are no network interfaces, each execution of OnAllocate will
+  // result in SignalCandidatesAllocationDone signal.
+  rtc::Thread::Current()->ProcessMessages(1000);
+  EXPECT_TRUE(candidate_allocation_done_);
+  EXPECT_EQ(0U, candidates_.size());
+}
+
+// Tests that we can get all the desired addresses successfully.
+TEST_F(PortAllocatorTest, TestGetAllPortsWithMinimumStepDelay) {
+  AddInterface(kClientAddr);
+  EXPECT_TRUE(CreateSession(cricket::ICE_CANDIDATE_COMPONENT_RTP));
+  session_->StartGettingPorts();
+  ASSERT_EQ_WAIT(7U, candidates_.size(), kDefaultAllocationTimeout);
+  EXPECT_EQ(4U, ports_.size());
+  EXPECT_PRED5(CheckCandidate, candidates_[0],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "local", "udp", kClientAddr);
+  EXPECT_PRED5(CheckCandidate, candidates_[1],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "stun", "udp", kClientAddr);
+  EXPECT_PRED5(CheckCandidate, candidates_[2],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "relay", "udp", kRelayUdpIntAddr);
+  EXPECT_PRED5(CheckCandidate, candidates_[3],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "relay", "udp", kRelayUdpExtAddr);
+  EXPECT_PRED5(CheckCandidate, candidates_[4],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "relay", "tcp", kRelayTcpIntAddr);
+  EXPECT_PRED5(CheckCandidate, candidates_[5],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "local", "tcp", kClientAddr);
+  EXPECT_PRED5(CheckCandidate, candidates_[6],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP,
+      "relay", "ssltcp", kRelaySslTcpIntAddr);
+  EXPECT_TRUE(candidate_allocation_done_);
+}
+
+// Verify candidates with default step delay of 1sec.
+TEST_F(PortAllocatorTest, TestGetAllPortsWithOneSecondStepDelay) {
+  AddInterface(kClientAddr);
+  allocator_->set_step_delay(cricket::kDefaultStepDelay);
+  EXPECT_TRUE(CreateSession(cricket::ICE_CANDIDATE_COMPONENT_RTP));
+  session_->StartGettingPorts();
+  ASSERT_EQ_WAIT(2U, candidates_.size(), 1000);
+  EXPECT_EQ(2U, ports_.size());
+  ASSERT_EQ_WAIT(4U, candidates_.size(), 2000);
+  EXPECT_EQ(3U, ports_.size());
+  EXPECT_PRED5(CheckCandidate, candidates_[2],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "relay", "udp", kRelayUdpIntAddr);
+  EXPECT_PRED5(CheckCandidate, candidates_[3],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "relay", "udp", kRelayUdpExtAddr);
+  ASSERT_EQ_WAIT(6U, candidates_.size(), 1500);
+  EXPECT_PRED5(CheckCandidate, candidates_[4],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "relay", "tcp", kRelayTcpIntAddr);
+  EXPECT_PRED5(CheckCandidate, candidates_[5],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "local", "tcp", kClientAddr);
+  EXPECT_EQ(4U, ports_.size());
+  ASSERT_EQ_WAIT(7U, candidates_.size(), 2000);
+  EXPECT_PRED5(CheckCandidate, candidates_[6],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP,
+               "relay", "ssltcp", kRelaySslTcpIntAddr);
+  EXPECT_EQ(4U, ports_.size());
+  EXPECT_TRUE(candidate_allocation_done_);
+  // If we Stop gathering now, we shouldn't get a second "done" callback.
+  session_->StopGettingPorts();
+}
+
+TEST_F(PortAllocatorTest, TestSetupVideoRtpPortsWithNormalSendBuffers) {
+  AddInterface(kClientAddr);
+  EXPECT_TRUE(CreateSession(cricket::ICE_CANDIDATE_COMPONENT_RTP,
+                            cricket::CN_VIDEO));
+  session_->StartGettingPorts();
+  ASSERT_EQ_WAIT(7U, candidates_.size(), kDefaultAllocationTimeout);
+  EXPECT_TRUE(candidate_allocation_done_);
+  // If we Stop gathering now, we shouldn't get a second "done" callback.
+  session_->StopGettingPorts();
+
+  // All ports should have unset send-buffer sizes.
+  CheckSendBufferSizesOfAllPorts(-1);
+}
+
+// Tests that we can get callback after StopGetAllPorts.
+TEST_F(PortAllocatorTest, TestStopGetAllPorts) {
+  AddInterface(kClientAddr);
+  EXPECT_TRUE(CreateSession(cricket::ICE_CANDIDATE_COMPONENT_RTP));
+  session_->StartGettingPorts();
+  ASSERT_EQ_WAIT(2U, candidates_.size(), kDefaultAllocationTimeout);
+  EXPECT_EQ(2U, ports_.size());
+  session_->StopGettingPorts();
+  EXPECT_TRUE_WAIT(candidate_allocation_done_, kDefaultAllocationTimeout);
+}
+
+// Test that we restrict client ports appropriately when a port range is set.
+// We check the candidates for udp/stun/tcp ports, and the from address
+// for relay ports.
+TEST_F(PortAllocatorTest, TestGetAllPortsPortRange) {
+  AddInterface(kClientAddr);
+  // Check that an invalid port range fails.
+  EXPECT_FALSE(SetPortRange(kMaxPort, kMinPort));
+  // Check that a null port range succeeds.
+  EXPECT_TRUE(SetPortRange(0, 0));
+  // Check that a valid port range succeeds.
+  EXPECT_TRUE(SetPortRange(kMinPort, kMaxPort));
+  EXPECT_TRUE(CreateSession(cricket::ICE_CANDIDATE_COMPONENT_RTP));
+  session_->StartGettingPorts();
+  ASSERT_EQ_WAIT(7U, candidates_.size(), kDefaultAllocationTimeout);
+  EXPECT_EQ(4U, ports_.size());
+  // Check the port number for the UDP port object.
+  EXPECT_PRED3(CheckPort, candidates_[0].address(), kMinPort, kMaxPort);
+  // Check the port number for the STUN port object.
+  EXPECT_PRED3(CheckPort, candidates_[1].address(), kMinPort, kMaxPort);
+  // Check the port number used to connect to the relay server.
+  EXPECT_PRED3(CheckPort, relay_server_.GetConnection(0).source(),
+               kMinPort, kMaxPort);
+  // Check the port number for the TCP port object.
+  EXPECT_PRED3(CheckPort, candidates_[5].address(), kMinPort, kMaxPort);
+  EXPECT_TRUE(candidate_allocation_done_);
+}
+
+// Test that we don't crash or malfunction if we have no network adapters.
+TEST_F(PortAllocatorTest, TestGetAllPortsNoAdapters) {
+  EXPECT_TRUE(CreateSession(cricket::ICE_CANDIDATE_COMPONENT_RTP));
+  session_->StartGettingPorts();
+  rtc::Thread::Current()->ProcessMessages(100);
+  // Without network adapter, we should not get any candidate.
+  EXPECT_EQ(0U, candidates_.size());
+  EXPECT_TRUE(candidate_allocation_done_);
+}
+
+// Test that we can get OnCandidatesAllocationDone callback when all the ports
+// are disabled.
+TEST_F(PortAllocatorTest, TestDisableAllPorts) {
+  AddInterface(kClientAddr);
+  EXPECT_TRUE(CreateSession(cricket::ICE_CANDIDATE_COMPONENT_RTP));
+  session_->set_flags(cricket::PORTALLOCATOR_DISABLE_UDP |
+                      cricket::PORTALLOCATOR_DISABLE_STUN |
+                      cricket::PORTALLOCATOR_DISABLE_RELAY |
+                      cricket::PORTALLOCATOR_DISABLE_TCP);
+  session_->StartGettingPorts();
+  rtc::Thread::Current()->ProcessMessages(100);
+  EXPECT_EQ(0U, candidates_.size());
+  EXPECT_TRUE(candidate_allocation_done_);
+}
+
+// Test that we don't crash or malfunction if we can't create UDP sockets.
+TEST_F(PortAllocatorTest, TestGetAllPortsNoUdpSockets) {
+  AddInterface(kClientAddr);
+  fss_->set_udp_sockets_enabled(false);
+  EXPECT_TRUE(CreateSession(1));
+  session_->StartGettingPorts();
+  ASSERT_EQ_WAIT(5U, candidates_.size(), kDefaultAllocationTimeout);
+  EXPECT_EQ(2U, ports_.size());
+  EXPECT_PRED5(CheckCandidate, candidates_[0],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "relay", "udp", kRelayUdpIntAddr);
+  EXPECT_PRED5(CheckCandidate, candidates_[1],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "relay", "udp", kRelayUdpExtAddr);
+  EXPECT_PRED5(CheckCandidate, candidates_[2],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "relay", "tcp", kRelayTcpIntAddr);
+  EXPECT_PRED5(CheckCandidate, candidates_[3],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "local", "tcp", kClientAddr);
+  EXPECT_PRED5(CheckCandidate, candidates_[4],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP,
+      "relay", "ssltcp", kRelaySslTcpIntAddr);
+  EXPECT_TRUE(candidate_allocation_done_);
+}
+
+// Test that we don't crash or malfunction if we can't create UDP sockets or
+// listen on TCP sockets. We still give out a local TCP address, since
+// apparently this is needed for the remote side to accept our connection.
+TEST_F(PortAllocatorTest, TestGetAllPortsNoUdpSocketsNoTcpListen) {
+  AddInterface(kClientAddr);
+  fss_->set_udp_sockets_enabled(false);
+  fss_->set_tcp_listen_enabled(false);
+  EXPECT_TRUE(CreateSession(1));
+  session_->StartGettingPorts();
+  ASSERT_EQ_WAIT(5U, candidates_.size(), kDefaultAllocationTimeout);
+  EXPECT_EQ(2U, ports_.size());
+  EXPECT_PRED5(CheckCandidate, candidates_[0],
+      1, "relay", "udp", kRelayUdpIntAddr);
+  EXPECT_PRED5(CheckCandidate, candidates_[1],
+      1, "relay", "udp", kRelayUdpExtAddr);
+  EXPECT_PRED5(CheckCandidate, candidates_[2],
+      1, "relay", "tcp", kRelayTcpIntAddr);
+  EXPECT_PRED5(CheckCandidate, candidates_[3],
+      1, "local", "tcp", kClientAddr);
+  EXPECT_PRED5(CheckCandidate, candidates_[4],
+      1, "relay", "ssltcp", kRelaySslTcpIntAddr);
+  EXPECT_TRUE(candidate_allocation_done_);
+}
+
+// Test that we don't crash or malfunction if we can't create any sockets.
+// TODO: Find a way to exit early here.
+TEST_F(PortAllocatorTest, TestGetAllPortsNoSockets) {
+  AddInterface(kClientAddr);
+  fss_->set_tcp_sockets_enabled(false);
+  fss_->set_udp_sockets_enabled(false);
+  EXPECT_TRUE(CreateSession(cricket::ICE_CANDIDATE_COMPONENT_RTP));
+  session_->StartGettingPorts();
+  WAIT(candidates_.size() > 0, 2000);
+  // TODO - Check candidate_allocation_done signal.
+  // In case of Relay, ports creation will succeed but sockets will fail.
+  // There is no error reporting from RelayEntry to handle this failure.
+}
+
+// Testing STUN timeout.
+TEST_F(PortAllocatorTest, TestGetAllPortsNoUdpAllowed) {
+  fss_->AddRule(false, rtc::FP_UDP, rtc::FD_ANY, kClientAddr);
+  AddInterface(kClientAddr);
+  EXPECT_TRUE(CreateSession(cricket::ICE_CANDIDATE_COMPONENT_RTP));
+  session_->StartGettingPorts();
+  EXPECT_EQ_WAIT(2U, candidates_.size(), kDefaultAllocationTimeout);
+  EXPECT_EQ(2U, ports_.size());
+  EXPECT_PRED5(CheckCandidate, candidates_[0],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "local", "udp", kClientAddr);
+  EXPECT_PRED5(CheckCandidate, candidates_[1],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "local", "tcp", kClientAddr);
+  // RelayPort connection timeout is 3sec. TCP connection with RelayServer
+  // will be tried after 3 seconds.
+  EXPECT_EQ_WAIT(6U, candidates_.size(), 4000);
+  EXPECT_EQ(3U, ports_.size());
+  EXPECT_PRED5(CheckCandidate, candidates_[2],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "relay", "udp", kRelayUdpIntAddr);
+  EXPECT_PRED5(CheckCandidate, candidates_[3],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "relay", "tcp", kRelayTcpIntAddr);
+  EXPECT_PRED5(CheckCandidate, candidates_[4],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "relay", "ssltcp",
+      kRelaySslTcpIntAddr);
+  EXPECT_PRED5(CheckCandidate, candidates_[5],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "relay", "udp", kRelayUdpExtAddr);
+  // Stun Timeout is 9sec.
+  EXPECT_TRUE_WAIT(candidate_allocation_done_, 9000);
+}
+
+TEST_F(PortAllocatorTest, TestCandidatePriorityOfMultipleInterfaces) {
+  AddInterface(kClientAddr);
+  AddInterface(kClientAddr2);
+  // Allocating only host UDP ports. This is done purely for testing
+  // convenience.
+  allocator().set_flags(cricket::PORTALLOCATOR_DISABLE_TCP |
+                        cricket::PORTALLOCATOR_DISABLE_STUN |
+                        cricket::PORTALLOCATOR_DISABLE_RELAY);
+  EXPECT_TRUE(CreateSession(cricket::ICE_CANDIDATE_COMPONENT_RTP));
+  session_->StartGettingPorts();
+  EXPECT_TRUE_WAIT(candidate_allocation_done_, kDefaultAllocationTimeout);
+  ASSERT_EQ(2U, candidates_.size());
+  EXPECT_EQ(2U, ports_.size());
+  // Candidates priorities should be different.
+  EXPECT_NE(candidates_[0].priority(), candidates_[1].priority());
+}
+
+// Test to verify ICE restart process.
+TEST_F(PortAllocatorTest, TestGetAllPortsRestarts) {
+  AddInterface(kClientAddr);
+  EXPECT_TRUE(CreateSession(cricket::ICE_CANDIDATE_COMPONENT_RTP));
+  session_->StartGettingPorts();
+  EXPECT_EQ_WAIT(7U, candidates_.size(), kDefaultAllocationTimeout);
+  EXPECT_EQ(4U, ports_.size());
+  EXPECT_TRUE(candidate_allocation_done_);
+  // TODO - Extend this to verify ICE restart.
+}
+
+// Test ICE candidate filter mechanism with options Relay/Host/Reflexive.
+// This test also verifies that when the allocator is only allowed to use
+// relay (i.e. IceTransportsType is relay), the raddr is an empty
+// address with the correct family. This is to prevent any local
+// reflective address leakage in the sdp line.
+TEST_F(PortAllocatorTest, TestCandidateFilterWithRelayOnly) {
+  AddInterface(kClientAddr);
+  // GTURN is not configured here.
+  ResetWithTurnServers(kTurnUdpIntAddr, rtc::SocketAddress());
+  allocator().set_candidate_filter(cricket::CF_RELAY);
+  EXPECT_TRUE(CreateSession(cricket::ICE_CANDIDATE_COMPONENT_RTP));
+  session_->StartGettingPorts();
+  EXPECT_TRUE_WAIT(candidate_allocation_done_, kDefaultAllocationTimeout);
+  EXPECT_PRED5(CheckCandidate,
+               candidates_[0],
+               cricket::ICE_CANDIDATE_COMPONENT_RTP,
+               "relay",
+               "udp",
+               rtc::SocketAddress(kTurnUdpExtAddr.ipaddr(), 0));
+
+  EXPECT_EQ(1U, candidates_.size());
+  EXPECT_EQ(1U, ports_.size());  // Only Relay port will be in ready state.
+  for (size_t i = 0; i < candidates_.size(); ++i) {
+    EXPECT_EQ(std::string(cricket::RELAY_PORT_TYPE), candidates_[i].type());
+    EXPECT_EQ(
+        candidates_[0].related_address(),
+        rtc::EmptySocketAddressWithFamily(candidates_[0].address().family()));
+  }
+}
+
+TEST_F(PortAllocatorTest, TestCandidateFilterWithHostOnly) {
+  AddInterface(kClientAddr);
+  allocator().set_flags(cricket::PORTALLOCATOR_ENABLE_SHARED_UFRAG |
+                        cricket::PORTALLOCATOR_ENABLE_SHARED_SOCKET);
+  allocator().set_candidate_filter(cricket::CF_HOST);
+  EXPECT_TRUE(CreateSession(cricket::ICE_CANDIDATE_COMPONENT_RTP));
+  session_->StartGettingPorts();
+  EXPECT_TRUE_WAIT(candidate_allocation_done_, kDefaultAllocationTimeout);
+  EXPECT_EQ(2U, candidates_.size()); // Host UDP/TCP candidates only.
+  EXPECT_EQ(2U, ports_.size()); // UDP/TCP ports only.
+  for (size_t i = 0; i < candidates_.size(); ++i) {
+    EXPECT_EQ(std::string(cricket::LOCAL_PORT_TYPE), candidates_[i].type());
+  }
+}
+
+// Host is behind the NAT.
+TEST_F(PortAllocatorTest, TestCandidateFilterWithReflexiveOnly) {
+  AddInterface(kPrivateAddr);
+  ResetWithNatServer(kStunAddr);
+
+  allocator().set_flags(cricket::PORTALLOCATOR_ENABLE_SHARED_UFRAG |
+                        cricket::PORTALLOCATOR_ENABLE_SHARED_SOCKET);
+  allocator().set_candidate_filter(cricket::CF_REFLEXIVE);
+  EXPECT_TRUE(CreateSession(cricket::ICE_CANDIDATE_COMPONENT_RTP));
+  session_->StartGettingPorts();
+  EXPECT_TRUE_WAIT(candidate_allocation_done_, kDefaultAllocationTimeout);
+  // Host is behind NAT, no private address will be exposed. Hence only UDP
+  // port with STUN candidate will be sent outside.
+  EXPECT_EQ(1U, candidates_.size()); // Only STUN candidate.
+  EXPECT_EQ(1U, ports_.size());  // Only UDP port will be in ready state.
+  for (size_t i = 0; i < candidates_.size(); ++i) {
+    EXPECT_EQ(std::string(cricket::STUN_PORT_TYPE), candidates_[i].type());
+    EXPECT_EQ(
+        candidates_[0].related_address(),
+        rtc::EmptySocketAddressWithFamily(candidates_[0].address().family()));
+  }
+}
+
+// Host is not behind the NAT.
+TEST_F(PortAllocatorTest, TestCandidateFilterWithReflexiveOnlyAndNoNAT) {
+  AddInterface(kClientAddr);
+  allocator().set_flags(cricket::PORTALLOCATOR_ENABLE_SHARED_UFRAG |
+                        cricket::PORTALLOCATOR_ENABLE_SHARED_SOCKET);
+  allocator().set_candidate_filter(cricket::CF_REFLEXIVE);
+  EXPECT_TRUE(CreateSession(cricket::ICE_CANDIDATE_COMPONENT_RTP));
+  session_->StartGettingPorts();
+  EXPECT_TRUE_WAIT(candidate_allocation_done_, kDefaultAllocationTimeout);
+  // Host has a public address, both UDP and TCP candidates will be exposed.
+  EXPECT_EQ(2U, candidates_.size()); // Local UDP + TCP candidate.
+  EXPECT_EQ(2U, ports_.size());  //  UDP and TCP ports will be in ready state.
+  for (size_t i = 0; i < candidates_.size(); ++i) {
+    EXPECT_EQ(std::string(cricket::LOCAL_PORT_TYPE), candidates_[i].type());
+  }
+}
+
+TEST_F(PortAllocatorTest, TestBasicMuxFeatures) {
+  AddInterface(kClientAddr);
+  allocator().set_flags(cricket::PORTALLOCATOR_ENABLE_BUNDLE);
+  // Session ID - session1.
+  rtc::scoped_ptr<cricket::PortAllocatorSession> session1(
+      CreateSession("session1", cricket::ICE_CANDIDATE_COMPONENT_RTP));
+  rtc::scoped_ptr<cricket::PortAllocatorSession> session2(
+      CreateSession("session1", cricket::ICE_CANDIDATE_COMPONENT_RTCP));
+  session1->StartGettingPorts();
+  session2->StartGettingPorts();
+  // Each session should receive two proxy ports of local and stun.
+  ASSERT_EQ_WAIT(14U, candidates_.size(), kDefaultAllocationTimeout);
+  EXPECT_EQ(8U, ports_.size());
+
+  rtc::scoped_ptr<cricket::PortAllocatorSession> session3(
+      CreateSession("session1", cricket::ICE_CANDIDATE_COMPONENT_RTP));
+  session3->StartGettingPorts();
+  // Already allocated candidates and ports will be sent to the newly
+  // allocated proxy session.
+  ASSERT_EQ_WAIT(21U, candidates_.size(), kDefaultAllocationTimeout);
+  EXPECT_EQ(12U, ports_.size());
+}
+
+// This test verifies by changing ice_ufrag and/or ice_pwd
+// will result in different set of candidates when BUNDLE is enabled.
+// If BUNDLE is disabled, CreateSession will always allocate new
+// set of candidates.
+TEST_F(PortAllocatorTest, TestBundleIceRestart) {
+  AddInterface(kClientAddr);
+  allocator().set_flags(cricket::PORTALLOCATOR_ENABLE_BUNDLE);
+  // Session ID - session1.
+  rtc::scoped_ptr<cricket::PortAllocatorSession> session1(
+      CreateSession("session1", kContentName,
+                    cricket::ICE_CANDIDATE_COMPONENT_RTP,
+                    kIceUfrag0, kIcePwd0));
+  session1->StartGettingPorts();
+  ASSERT_EQ_WAIT(7U, candidates_.size(), kDefaultAllocationTimeout);
+  EXPECT_EQ(4U, ports_.size());
+
+  // Allocate a different session with sid |session1| and different ice_ufrag.
+  rtc::scoped_ptr<cricket::PortAllocatorSession> session2(
+      CreateSession("session1", kContentName,
+                    cricket::ICE_CANDIDATE_COMPONENT_RTP,
+                    "TestIceUfrag", kIcePwd0));
+  session2->StartGettingPorts();
+  ASSERT_EQ_WAIT(14U, candidates_.size(), kDefaultAllocationTimeout);
+  EXPECT_EQ(8U, ports_.size());
+  // Verifying the candidate address different from previously allocated
+  // address.
+  // Skipping verification of component id and candidate type.
+  EXPECT_NE(candidates_[0].address(), candidates_[7].address());
+  EXPECT_NE(candidates_[1].address(), candidates_[8].address());
+
+  // Allocating a different session with sid |session1| and
+  // different ice_pwd.
+  rtc::scoped_ptr<cricket::PortAllocatorSession> session3(
+      CreateSession("session1", kContentName,
+                    cricket::ICE_CANDIDATE_COMPONENT_RTP,
+                    kIceUfrag0, "TestIcePwd"));
+  session3->StartGettingPorts();
+  ASSERT_EQ_WAIT(21U, candidates_.size(), kDefaultAllocationTimeout);
+  EXPECT_EQ(12U, ports_.size());
+  // Verifying the candidate address different from previously
+  // allocated address.
+  EXPECT_NE(candidates_[7].address(), candidates_[14].address());
+  EXPECT_NE(candidates_[8].address(), candidates_[15].address());
+
+  // Allocating a session with by changing both ice_ufrag and ice_pwd.
+  rtc::scoped_ptr<cricket::PortAllocatorSession> session4(
+      CreateSession("session1", kContentName,
+                    cricket::ICE_CANDIDATE_COMPONENT_RTP,
+                    "TestIceUfrag", "TestIcePwd"));
+  session4->StartGettingPorts();
+  ASSERT_EQ_WAIT(28U, candidates_.size(), kDefaultAllocationTimeout);
+  EXPECT_EQ(16U, ports_.size());
+  // Verifying the candidate address different from previously
+  // allocated address.
+  EXPECT_NE(candidates_[14].address(), candidates_[21].address());
+  EXPECT_NE(candidates_[15].address(), candidates_[22].address());
+}
+
+// Test that when the PORTALLOCATOR_ENABLE_SHARED_UFRAG is enabled we got same
+// ufrag and pwd for the collected candidates.
+TEST_F(PortAllocatorTest, TestEnableSharedUfrag) {
+  allocator().set_flags(allocator().flags() |
+                        cricket::PORTALLOCATOR_ENABLE_SHARED_UFRAG);
+  AddInterface(kClientAddr);
+  EXPECT_TRUE(CreateSession(cricket::ICE_CANDIDATE_COMPONENT_RTP));
+  session_->StartGettingPorts();
+  ASSERT_EQ_WAIT(7U, candidates_.size(), kDefaultAllocationTimeout);
+  EXPECT_PRED5(CheckCandidate, candidates_[0],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "local", "udp", kClientAddr);
+  EXPECT_PRED5(CheckCandidate, candidates_[1],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "stun", "udp", kClientAddr);
+  EXPECT_PRED5(CheckCandidate, candidates_[5],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "local", "tcp", kClientAddr);
+  EXPECT_EQ(4U, ports_.size());
+  EXPECT_EQ(kIceUfrag0, candidates_[0].username());
+  EXPECT_EQ(kIceUfrag0, candidates_[1].username());
+  EXPECT_EQ(kIceUfrag0, candidates_[2].username());
+  EXPECT_EQ(kIcePwd0, candidates_[0].password());
+  EXPECT_EQ(kIcePwd0, candidates_[1].password());
+  EXPECT_TRUE(candidate_allocation_done_);
+}
+
+// Test that when the PORTALLOCATOR_ENABLE_SHARED_UFRAG isn't enabled we got
+// different ufrag and pwd for the collected candidates.
+TEST_F(PortAllocatorTest, TestDisableSharedUfrag) {
+  allocator().set_flags(allocator().flags() &
+                        ~cricket::PORTALLOCATOR_ENABLE_SHARED_UFRAG);
+  AddInterface(kClientAddr);
+  EXPECT_TRUE(CreateSession(cricket::ICE_CANDIDATE_COMPONENT_RTP));
+  session_->StartGettingPorts();
+  ASSERT_EQ_WAIT(7U, candidates_.size(), kDefaultAllocationTimeout);
+  EXPECT_PRED5(CheckCandidate, candidates_[0],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "local", "udp", kClientAddr);
+  EXPECT_PRED5(CheckCandidate, candidates_[1],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "stun", "udp", kClientAddr);
+  EXPECT_EQ(4U, ports_.size());
+  // Port should generate random ufrag and pwd.
+  EXPECT_NE(kIceUfrag0, candidates_[0].username());
+  EXPECT_NE(kIceUfrag0, candidates_[1].username());
+  EXPECT_NE(candidates_[0].username(), candidates_[1].username());
+  EXPECT_NE(kIcePwd0, candidates_[0].password());
+  EXPECT_NE(kIcePwd0, candidates_[1].password());
+  EXPECT_NE(candidates_[0].password(), candidates_[1].password());
+  EXPECT_TRUE(candidate_allocation_done_);
+}
+
+// Test that when PORTALLOCATOR_ENABLE_SHARED_SOCKET is enabled only one port
+// is allocated for udp and stun. Also verify there is only one candidate
+// (local) if stun candidate is same as local candidate, which will be the case
+// in a public network like the below test.
+TEST_F(PortAllocatorTest, TestSharedSocketWithoutNat) {
+  AddInterface(kClientAddr);
+  allocator_->set_flags(allocator().flags() |
+                        cricket::PORTALLOCATOR_ENABLE_SHARED_UFRAG |
+                        cricket::PORTALLOCATOR_ENABLE_SHARED_SOCKET);
+  EXPECT_TRUE(CreateSession(cricket::ICE_CANDIDATE_COMPONENT_RTP));
+  session_->StartGettingPorts();
+  ASSERT_EQ_WAIT(6U, candidates_.size(), kDefaultAllocationTimeout);
+  EXPECT_EQ(3U, ports_.size());
+  EXPECT_PRED5(CheckCandidate, candidates_[0],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "local", "udp", kClientAddr);
+  EXPECT_TRUE_WAIT(candidate_allocation_done_, kDefaultAllocationTimeout);
+}
+
+// Test that when PORTALLOCATOR_ENABLE_SHARED_SOCKET is enabled only one port
+// is allocated for udp and stun. In this test we should expect both stun and
+// local candidates as client behind a nat.
+TEST_F(PortAllocatorTest, TestSharedSocketWithNat) {
+  AddInterface(kClientAddr);
+  ResetWithNatServer(kStunAddr);
+
+  allocator_->set_flags(allocator().flags() |
+                        cricket::PORTALLOCATOR_ENABLE_SHARED_UFRAG |
+                        cricket::PORTALLOCATOR_ENABLE_SHARED_SOCKET);
+  EXPECT_TRUE(CreateSession(cricket::ICE_CANDIDATE_COMPONENT_RTP));
+  session_->StartGettingPorts();
+  ASSERT_EQ_WAIT(3U, candidates_.size(), kDefaultAllocationTimeout);
+  ASSERT_EQ(2U, ports_.size());
+  EXPECT_PRED5(CheckCandidate, candidates_[0],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "local", "udp", kClientAddr);
+  EXPECT_PRED5(CheckCandidate, candidates_[1],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "stun", "udp",
+      rtc::SocketAddress(kNatAddr.ipaddr(), 0));
+  EXPECT_TRUE_WAIT(candidate_allocation_done_, kDefaultAllocationTimeout);
+  EXPECT_EQ(3U, candidates_.size());
+}
+
+// Test TURN port in shared socket mode with UDP and TCP TURN server adderesses.
+TEST_F(PortAllocatorTest, TestSharedSocketWithoutNatUsingTurn) {
+  turn_server_.AddInternalSocket(kTurnTcpIntAddr, cricket::PROTO_TCP);
+  AddInterface(kClientAddr);
+  allocator_.reset(new cricket::BasicPortAllocator(&network_manager_));
+
+  AddTurnServers(kTurnUdpIntAddr, kTurnTcpIntAddr);
+
+  allocator_->set_step_delay(cricket::kMinimumStepDelay);
+  allocator_->set_flags(allocator().flags() |
+                        cricket::PORTALLOCATOR_ENABLE_SHARED_UFRAG |
+                        cricket::PORTALLOCATOR_ENABLE_SHARED_SOCKET |
+                        cricket::PORTALLOCATOR_DISABLE_TCP);
+
+  EXPECT_TRUE(CreateSession(cricket::ICE_CANDIDATE_COMPONENT_RTP));
+  session_->StartGettingPorts();
+
+  ASSERT_EQ_WAIT(3U, candidates_.size(), kDefaultAllocationTimeout);
+  ASSERT_EQ(3U, ports_.size());
+  EXPECT_PRED5(CheckCandidate, candidates_[0],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "local", "udp", kClientAddr);
+  EXPECT_PRED5(CheckCandidate, candidates_[1],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "relay", "udp",
+      rtc::SocketAddress(kTurnUdpExtAddr.ipaddr(), 0));
+  EXPECT_PRED5(CheckCandidate, candidates_[2],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "relay", "udp",
+      rtc::SocketAddress(kTurnUdpExtAddr.ipaddr(), 0));
+  EXPECT_TRUE_WAIT(candidate_allocation_done_, kDefaultAllocationTimeout);
+  EXPECT_EQ(3U, candidates_.size());
+}
+
+// Testing DNS resolve for the TURN server, this will test AllocationSequence
+// handling the unresolved address signal from TurnPort.
+TEST_F(PortAllocatorTest, TestSharedSocketWithServerAddressResolve) {
+  turn_server_.AddInternalSocket(rtc::SocketAddress("127.0.0.1", 3478),
+                                 cricket::PROTO_UDP);
+  AddInterface(kClientAddr);
+  allocator_.reset(new cricket::BasicPortAllocator(&network_manager_));
+  cricket::RelayServerConfig relay_server(cricket::RELAY_TURN);
+  cricket::RelayCredentials credentials(kTurnUsername, kTurnPassword);
+  relay_server.credentials = credentials;
+  relay_server.ports.push_back(cricket::ProtocolAddress(
+      rtc::SocketAddress("localhost", 3478),
+      cricket::PROTO_UDP, false));
+  allocator_->AddRelay(relay_server);
+
+  allocator_->set_step_delay(cricket::kMinimumStepDelay);
+  allocator_->set_flags(allocator().flags() |
+                        cricket::PORTALLOCATOR_ENABLE_SHARED_UFRAG |
+                        cricket::PORTALLOCATOR_ENABLE_SHARED_SOCKET |
+                        cricket::PORTALLOCATOR_DISABLE_TCP);
+
+  EXPECT_TRUE(CreateSession(cricket::ICE_CANDIDATE_COMPONENT_RTP));
+  session_->StartGettingPorts();
+
+  EXPECT_EQ_WAIT(2U, ports_.size(), kDefaultAllocationTimeout);
+}
+
+// Test that when PORTALLOCATOR_ENABLE_SHARED_SOCKET is enabled only one port
+// is allocated for udp/stun/turn. In this test we should expect all local,
+// stun and turn candidates.
+TEST_F(PortAllocatorTest, TestSharedSocketWithNatUsingTurn) {
+  AddInterface(kClientAddr);
+  ResetWithNatServer(kStunAddr);
+
+  AddTurnServers(kTurnUdpIntAddr, rtc::SocketAddress());
+
+  allocator_->set_flags(allocator().flags() |
+                        cricket::PORTALLOCATOR_ENABLE_SHARED_UFRAG |
+                        cricket::PORTALLOCATOR_ENABLE_SHARED_SOCKET |
+                        cricket::PORTALLOCATOR_DISABLE_TCP);
+
+  EXPECT_TRUE(CreateSession(cricket::ICE_CANDIDATE_COMPONENT_RTP));
+  session_->StartGettingPorts();
+
+  ASSERT_EQ_WAIT(3U, candidates_.size(), kDefaultAllocationTimeout);
+  ASSERT_EQ(2U, ports_.size());
+  EXPECT_PRED5(CheckCandidate, candidates_[0],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "local", "udp", kClientAddr);
+  EXPECT_PRED5(CheckCandidate, candidates_[1],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "stun", "udp",
+      rtc::SocketAddress(kNatAddr.ipaddr(), 0));
+  EXPECT_PRED5(CheckCandidate, candidates_[2],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "relay", "udp",
+      rtc::SocketAddress(kTurnUdpExtAddr.ipaddr(), 0));
+  EXPECT_TRUE_WAIT(candidate_allocation_done_, kDefaultAllocationTimeout);
+  EXPECT_EQ(3U, candidates_.size());
+  // Local port will be created first and then TURN port.
+  EXPECT_EQ(2U, ports_[0]->Candidates().size());
+  EXPECT_EQ(1U, ports_[1]->Candidates().size());
+}
+
+// Test that when PORTALLOCATOR_ENABLE_SHARED_SOCKET is enabled and the TURN
+// server is also used as the STUN server, we should get 'local', 'stun', and
+// 'relay' candidates.
+TEST_F(PortAllocatorTest, TestSharedSocketWithNatUsingTurnAsStun) {
+  AddInterface(kClientAddr);
+  ResetWithNatServer(kTurnUdpIntAddr);
+  AddTurnServers(kTurnUdpIntAddr, rtc::SocketAddress());
+
+  // Must set the step delay to 0 to make sure the relay allocation phase is
+  // started before the STUN candidates are obtained, so that the STUN binding
+  // response is processed when both StunPort and TurnPort exist to reproduce
+  // webrtc issue 3537.
+  allocator_->set_step_delay(0);
+  allocator_->set_flags(allocator().flags() |
+                        cricket::PORTALLOCATOR_ENABLE_SHARED_UFRAG |
+                        cricket::PORTALLOCATOR_ENABLE_SHARED_SOCKET |
+                        cricket::PORTALLOCATOR_DISABLE_TCP);
+
+  EXPECT_TRUE(CreateSession(cricket::ICE_CANDIDATE_COMPONENT_RTP));
+  session_->StartGettingPorts();
+
+  ASSERT_EQ_WAIT(3U, candidates_.size(), kDefaultAllocationTimeout);
+  EXPECT_PRED5(CheckCandidate, candidates_[0],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "local", "udp", kClientAddr);
+  EXPECT_PRED5(CheckCandidate, candidates_[1],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "stun", "udp",
+      rtc::SocketAddress(kNatAddr.ipaddr(), 0));
+  EXPECT_PRED5(CheckCandidate, candidates_[2],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "relay", "udp",
+      rtc::SocketAddress(kTurnUdpExtAddr.ipaddr(), 0));
+  EXPECT_EQ(candidates_[2].related_address(), candidates_[1].address());
+
+  EXPECT_TRUE_WAIT(candidate_allocation_done_, kDefaultAllocationTimeout);
+  EXPECT_EQ(3U, candidates_.size());
+  // Local port will be created first and then TURN port.
+  EXPECT_EQ(2U, ports_[0]->Candidates().size());
+  EXPECT_EQ(1U, ports_[1]->Candidates().size());
+}
+
+// This test verifies when PORTALLOCATOR_ENABLE_SHARED_SOCKET flag is enabled
+// and fail to generate STUN candidate, local UDP candidate is generated
+// properly.
+TEST_F(PortAllocatorTest, TestSharedSocketNoUdpAllowed) {
+  allocator().set_flags(allocator().flags() |
+                        cricket::PORTALLOCATOR_DISABLE_RELAY |
+                        cricket::PORTALLOCATOR_DISABLE_TCP |
+                        cricket::PORTALLOCATOR_ENABLE_SHARED_UFRAG |
+                        cricket::PORTALLOCATOR_ENABLE_SHARED_SOCKET);
+  fss_->AddRule(false, rtc::FP_UDP, rtc::FD_ANY, kClientAddr);
+  AddInterface(kClientAddr);
+  EXPECT_TRUE(CreateSession(cricket::ICE_CANDIDATE_COMPONENT_RTP));
+  session_->StartGettingPorts();
+  ASSERT_EQ_WAIT(1U, ports_.size(), kDefaultAllocationTimeout);
+  EXPECT_EQ(1U, candidates_.size());
+  EXPECT_PRED5(CheckCandidate, candidates_[0],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "local", "udp", kClientAddr);
+  // STUN timeout is 9sec. We need to wait to get candidate done signal.
+  EXPECT_TRUE_WAIT(candidate_allocation_done_, 10000);
+  EXPECT_EQ(1U, candidates_.size());
+}
+
+// This test verifies allocator can use IPv6 addresses along with IPv4.
+TEST_F(PortAllocatorTest, TestEnableIPv6Addresses) {
+  allocator().set_flags(allocator().flags() |
+                        cricket::PORTALLOCATOR_DISABLE_RELAY |
+                        cricket::PORTALLOCATOR_ENABLE_IPV6 |
+                        cricket::PORTALLOCATOR_ENABLE_SHARED_UFRAG |
+                        cricket::PORTALLOCATOR_ENABLE_SHARED_SOCKET);
+  AddInterface(kClientIPv6Addr);
+  AddInterface(kClientAddr);
+  allocator_->set_step_delay(cricket::kMinimumStepDelay);
+  EXPECT_TRUE(CreateSession(cricket::ICE_CANDIDATE_COMPONENT_RTP));
+  session_->StartGettingPorts();
+  ASSERT_EQ_WAIT(4U, ports_.size(), kDefaultAllocationTimeout);
+  EXPECT_EQ(4U, candidates_.size());
+  EXPECT_TRUE_WAIT(candidate_allocation_done_, kDefaultAllocationTimeout);
+  EXPECT_PRED5(CheckCandidate, candidates_[0],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "local", "udp",
+      kClientIPv6Addr);
+  EXPECT_PRED5(CheckCandidate, candidates_[1],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "local", "udp",
+      kClientAddr);
+  EXPECT_PRED5(CheckCandidate, candidates_[2],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "local", "tcp",
+      kClientIPv6Addr);
+  EXPECT_PRED5(CheckCandidate, candidates_[3],
+      cricket::ICE_CANDIDATE_COMPONENT_RTP, "local", "tcp",
+      kClientAddr);
+  EXPECT_EQ(4U, candidates_.size());
+}
+
+// Test that the httpportallocator correctly maintains its lists of stun and
+// relay servers, by never allowing an empty list.
+TEST(HttpPortAllocatorTest, TestHttpPortAllocatorHostLists) {
+  rtc::FakeNetworkManager network_manager;
+  cricket::HttpPortAllocator alloc(&network_manager, "unit test agent");
+  EXPECT_EQ(1U, alloc.relay_hosts().size());
+  EXPECT_EQ(1U, alloc.stun_hosts().size());
+
+  std::vector<std::string> relay_servers;
+  std::vector<rtc::SocketAddress> stun_servers;
+
+  alloc.SetRelayHosts(relay_servers);
+  alloc.SetStunHosts(stun_servers);
+  EXPECT_EQ(1U, alloc.relay_hosts().size());
+  EXPECT_EQ(1U, alloc.stun_hosts().size());
+
+  relay_servers.push_back("1.unittest.corp.google.com");
+  relay_servers.push_back("2.unittest.corp.google.com");
+  stun_servers.push_back(
+      rtc::SocketAddress("1.unittest.corp.google.com", 0));
+  stun_servers.push_back(
+      rtc::SocketAddress("2.unittest.corp.google.com", 0));
+
+  alloc.SetRelayHosts(relay_servers);
+  alloc.SetStunHosts(stun_servers);
+  EXPECT_EQ(2U, alloc.relay_hosts().size());
+  EXPECT_EQ(2U, alloc.stun_hosts().size());
+}
+
+// Test that the HttpPortAllocator uses correct URL to create sessions.
+TEST(HttpPortAllocatorTest, TestSessionRequestUrl) {
+  rtc::FakeNetworkManager network_manager;
+  cricket::HttpPortAllocator alloc(&network_manager, "unit test agent");
+
+  // Disable PORTALLOCATOR_ENABLE_SHARED_UFRAG.
+  alloc.set_flags(alloc.flags() & ~cricket::PORTALLOCATOR_ENABLE_SHARED_UFRAG);
+  rtc::scoped_ptr<cricket::HttpPortAllocatorSessionBase> session(
+      static_cast<cricket::HttpPortAllocatorSession*>(
+          alloc.CreateSessionInternal(
+              "test content", 0, kIceUfrag0, kIcePwd0)));
+  std::string url = session->GetSessionRequestUrl();
+  LOG(LS_INFO) << "url: " << url;
+  EXPECT_EQ(std::string(cricket::HttpPortAllocator::kCreateSessionURL), url);
+
+  // Enable PORTALLOCATOR_ENABLE_SHARED_UFRAG.
+  alloc.set_flags(alloc.flags() | cricket::PORTALLOCATOR_ENABLE_SHARED_UFRAG);
+  session.reset(static_cast<cricket::HttpPortAllocatorSession*>(
+      alloc.CreateSessionInternal("test content", 0, kIceUfrag0, kIcePwd0)));
+  url = session->GetSessionRequestUrl();
+  LOG(LS_INFO) << "url: " << url;
+  std::vector<std::string> parts;
+  rtc::split(url, '?', &parts);
+  ASSERT_EQ(2U, parts.size());
+
+  std::vector<std::string> args_parts;
+  rtc::split(parts[1], '&', &args_parts);
+
+  std::map<std::string, std::string> args;
+  for (std::vector<std::string>::iterator it = args_parts.begin();
+       it != args_parts.end(); ++it) {
+    std::vector<std::string> parts;
+    rtc::split(*it, '=', &parts);
+    ASSERT_EQ(2U, parts.size());
+    args[rtc::s_url_decode(parts[0])] = rtc::s_url_decode(parts[1]);
+  }
+
+  EXPECT_EQ(kIceUfrag0, args["username"]);
+  EXPECT_EQ(kIcePwd0, args["password"]);
+}
diff --git a/webrtc/p2p/client/sessionmanagertask.h b/webrtc/p2p/client/sessionmanagertask.h
new file mode 100644
index 0000000..04d79d4
--- /dev/null
+++ b/webrtc/p2p/client/sessionmanagertask.h
@@ -0,0 +1,76 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_CLIENT_SESSIONMANAGERTASK_H_
+#define WEBRTC_P2P_CLIENT_SESSIONMANAGERTASK_H_
+
+#include "webrtc/p2p/base/sessionmanager.h"
+#include "webrtc/p2p/client/sessionsendtask.h"
+#include "webrtc/libjingle/xmpp/xmppengine.h"
+#include "webrtc/libjingle/xmpp/xmpptask.h"
+
+namespace cricket {
+
+// This class handles sending and receiving XMPP messages on behalf of the
+// SessionManager.  The sending part is handed over to SessionSendTask.
+
+class SessionManagerTask : public buzz::XmppTask {
+ public:
+  SessionManagerTask(buzz::XmppTaskParentInterface* parent,
+                     SessionManager* session_manager)
+      : buzz::XmppTask(parent, buzz::XmppEngine::HL_SINGLE),
+        session_manager_(session_manager) {
+  }
+
+  ~SessionManagerTask() {
+  }
+
+  // Turns on simple support for sending messages, using SessionSendTask.
+  void EnableOutgoingMessages() {
+    session_manager_->SignalOutgoingMessage.connect(
+        this, &SessionManagerTask::OnOutgoingMessage);
+    session_manager_->SignalRequestSignaling.connect(
+        session_manager_, &SessionManager::OnSignalingReady);
+  }
+
+  virtual int ProcessStart() {
+    const buzz::XmlElement *stanza = NextStanza();
+    if (stanza == NULL)
+      return STATE_BLOCKED;
+    session_manager_->OnIncomingMessage(stanza);
+    return STATE_START;
+  }
+
+ protected:
+  virtual bool HandleStanza(const buzz::XmlElement *stanza) {
+    if (!session_manager_->IsSessionMessage(stanza))
+      return false;
+    // Responses are handled by the SessionSendTask that sent the request.
+    //if (stanza->Attr(buzz::QN_TYPE) != buzz::STR_SET)
+    //  return false;
+    QueueStanza(stanza);
+    return true;
+  }
+
+ private:
+  void OnOutgoingMessage(SessionManager* manager,
+                         const buzz::XmlElement* stanza) {
+    cricket::SessionSendTask* sender =
+        new cricket::SessionSendTask(parent_, session_manager_);
+    sender->Send(stanza);
+    sender->Start();
+  }
+
+  SessionManager* session_manager_;
+};
+
+}  // namespace cricket
+
+#endif // WEBRTC_P2P_CLIENT_SESSIONMANAGERTASK_H_
diff --git a/webrtc/p2p/client/sessionsendtask.h b/webrtc/p2p/client/sessionsendtask.h
new file mode 100644
index 0000000..818aa1a
--- /dev/null
+++ b/webrtc/p2p/client/sessionsendtask.h
@@ -0,0 +1,128 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_CLIENT_SESSIONSENDTASK_H_
+#define WEBRTC_P2P_CLIENT_SESSIONSENDTASK_H_
+
+#include "webrtc/p2p/base/sessionmanager.h"
+#include "webrtc/libjingle/xmpp/constants.h"
+#include "webrtc/libjingle/xmpp/xmppclient.h"
+#include "webrtc/libjingle/xmpp/xmppengine.h"
+#include "webrtc/libjingle/xmpp/xmpptask.h"
+#include "webrtc/base/common.h"
+
+namespace cricket {
+
+// The job of this task is to send an IQ stanza out (after stamping it with
+// an ID attribute) and then wait for a response.  If not response happens
+// within 5 seconds, it will signal failure on a SessionManager.  If an error
+// happens it will also signal failure.  If, however, the send succeeds this
+// task will quietly go away.
+
+class SessionSendTask : public buzz::XmppTask {
+ public:
+  SessionSendTask(buzz::XmppTaskParentInterface* parent,
+                  SessionManager* session_manager)
+    : buzz::XmppTask(parent, buzz::XmppEngine::HL_SINGLE),
+      session_manager_(session_manager) {
+    set_timeout_seconds(15);
+    session_manager_->SignalDestroyed.connect(
+        this, &SessionSendTask::OnSessionManagerDestroyed);
+  }
+
+  virtual ~SessionSendTask() {
+    SignalDone(this);
+  }
+
+  void Send(const buzz::XmlElement* stanza) {
+    ASSERT(stanza_.get() == NULL);
+
+    // This should be an IQ of type set, result, or error.  In the first case,
+    // we supply an ID.  In the others, it should be present.
+    ASSERT(stanza->Name() == buzz::QN_IQ);
+    ASSERT(stanza->HasAttr(buzz::QN_TYPE));
+    if (stanza->Attr(buzz::QN_TYPE) == "set") {
+      ASSERT(!stanza->HasAttr(buzz::QN_ID));
+    } else {
+      ASSERT((stanza->Attr(buzz::QN_TYPE) == "result") ||
+             (stanza->Attr(buzz::QN_TYPE) == "error"));
+      ASSERT(stanza->HasAttr(buzz::QN_ID));
+    }
+
+    stanza_.reset(new buzz::XmlElement(*stanza));
+    if (stanza_->HasAttr(buzz::QN_ID)) {
+      set_task_id(stanza_->Attr(buzz::QN_ID));
+    } else {
+      stanza_->SetAttr(buzz::QN_ID, task_id());
+    }
+  }
+
+  void OnSessionManagerDestroyed() {
+    // If the session manager doesn't exist anymore, we should still try to
+    // send the message, but avoid calling back into the SessionManager.
+    session_manager_ = NULL;
+  }
+
+  sigslot::signal1<SessionSendTask *> SignalDone;
+
+ protected:
+  virtual int OnTimeout() {
+    if (session_manager_ != NULL) {
+      session_manager_->OnFailedSend(stanza_.get(), NULL);
+    }
+
+    return XmppTask::OnTimeout();
+  }
+
+  virtual int ProcessStart() {
+    SendStanza(stanza_.get());
+    if (stanza_->Attr(buzz::QN_TYPE) == buzz::STR_SET) {
+      return STATE_RESPONSE;
+    } else {
+      return STATE_DONE;
+    }
+  }
+
+  virtual int ProcessResponse() {
+    const buzz::XmlElement* next = NextStanza();
+    if (next == NULL)
+      return STATE_BLOCKED;
+
+    if (session_manager_ != NULL) {
+      if (next->Attr(buzz::QN_TYPE) == buzz::STR_RESULT) {
+        session_manager_->OnIncomingResponse(stanza_.get(), next);
+      } else {
+        session_manager_->OnFailedSend(stanza_.get(), next);
+      }
+    }
+
+    return STATE_DONE;
+  }
+
+  virtual bool HandleStanza(const buzz::XmlElement *stanza) {
+    if (!MatchResponseIq(stanza,
+                         buzz::Jid(stanza_->Attr(buzz::QN_TO)), task_id()))
+      return false;
+    if (stanza->Attr(buzz::QN_TYPE) == buzz::STR_RESULT ||
+        stanza->Attr(buzz::QN_TYPE) == buzz::STR_ERROR) {
+      QueueStanza(stanza);
+      return true;
+    }
+    return false;
+  }
+
+ private:
+  SessionManager *session_manager_;
+  rtc::scoped_ptr<buzz::XmlElement> stanza_;
+};
+
+}
+
+#endif // WEBRTC_P2P_CLIENT_SESSIONSENDTASK_H_
diff --git a/webrtc/p2p/client/socketmonitor.cc b/webrtc/p2p/client/socketmonitor.cc
new file mode 100644
index 0000000..5245535
--- /dev/null
+++ b/webrtc/p2p/client/socketmonitor.cc
@@ -0,0 +1,97 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/p2p/client/socketmonitor.h"
+
+#include "webrtc/base/common.h"
+
+namespace cricket {
+
+enum {
+  MSG_MONITOR_POLL,
+  MSG_MONITOR_START,
+  MSG_MONITOR_STOP,
+  MSG_MONITOR_SIGNAL
+};
+
+SocketMonitor::SocketMonitor(TransportChannel* channel,
+                             rtc::Thread* worker_thread,
+                             rtc::Thread* monitor_thread) {
+  channel_ = channel;
+  channel_thread_ = worker_thread;
+  monitoring_thread_ = monitor_thread;
+  monitoring_ = false;
+}
+
+SocketMonitor::~SocketMonitor() {
+  channel_thread_->Clear(this);
+  monitoring_thread_->Clear(this);
+}
+
+void SocketMonitor::Start(int milliseconds) {
+  rate_ = milliseconds;
+  if (rate_ < 250)
+    rate_ = 250;
+  channel_thread_->Post(this, MSG_MONITOR_START);
+}
+
+void SocketMonitor::Stop() {
+  channel_thread_->Post(this, MSG_MONITOR_STOP);
+}
+
+void SocketMonitor::OnMessage(rtc::Message *message) {
+  rtc::CritScope cs(&crit_);
+  switch (message->message_id) {
+    case MSG_MONITOR_START:
+      ASSERT(rtc::Thread::Current() == channel_thread_);
+      if (!monitoring_) {
+        monitoring_ = true;
+        PollSocket(true);
+      }
+      break;
+
+    case MSG_MONITOR_STOP:
+      ASSERT(rtc::Thread::Current() == channel_thread_);
+      if (monitoring_) {
+        monitoring_ = false;
+        channel_thread_->Clear(this);
+      }
+      break;
+
+    case MSG_MONITOR_POLL:
+      ASSERT(rtc::Thread::Current() == channel_thread_);
+      PollSocket(true);
+      break;
+
+    case MSG_MONITOR_SIGNAL: {
+      ASSERT(rtc::Thread::Current() == monitoring_thread_);
+      std::vector<ConnectionInfo> infos = connection_infos_;
+      crit_.Leave();
+      SignalUpdate(this, infos);
+      crit_.Enter();
+      break;
+    }
+  }
+}
+
+void SocketMonitor::PollSocket(bool poll) {
+  ASSERT(rtc::Thread::Current() == channel_thread_);
+  rtc::CritScope cs(&crit_);
+
+  // Gather connection infos
+  channel_->GetStats(&connection_infos_);
+
+  // Signal the monitoring thread, start another poll timer
+  monitoring_thread_->Post(this, MSG_MONITOR_SIGNAL);
+  if (poll)
+    channel_thread_->PostDelayed(rate_, this, MSG_MONITOR_POLL);
+}
+
+}  // namespace cricket
diff --git a/webrtc/p2p/client/socketmonitor.h b/webrtc/p2p/client/socketmonitor.h
new file mode 100644
index 0000000..5c10a4ec
--- /dev/null
+++ b/webrtc/p2p/client/socketmonitor.h
@@ -0,0 +1,54 @@
+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_CLIENT_SOCKETMONITOR_H_
+#define WEBRTC_P2P_CLIENT_SOCKETMONITOR_H_
+
+#include <vector>
+
+#include "webrtc/p2p/base/transportchannel.h"
+#include "webrtc/base/criticalsection.h"
+#include "webrtc/base/sigslot.h"
+#include "webrtc/base/thread.h"
+
+namespace cricket {
+
+class SocketMonitor : public rtc::MessageHandler,
+                      public sigslot::has_slots<> {
+ public:
+  SocketMonitor(TransportChannel* channel,
+                rtc::Thread* worker_thread,
+                rtc::Thread* monitor_thread);
+  ~SocketMonitor();
+
+  void Start(int cms);
+  void Stop();
+
+  rtc::Thread* monitor_thread() { return monitoring_thread_; }
+
+  sigslot::signal2<SocketMonitor*,
+                   const std::vector<ConnectionInfo>&> SignalUpdate;
+
+ protected:
+  void OnMessage(rtc::Message* message);
+  void PollSocket(bool poll);
+
+  std::vector<ConnectionInfo> connection_infos_;
+  TransportChannel* channel_;
+  rtc::Thread* channel_thread_;
+  rtc::Thread* monitoring_thread_;
+  rtc::CriticalSection crit_;
+  uint32 rate_;
+  bool monitoring_;
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_CLIENT_SOCKETMONITOR_H_
diff --git a/webrtc/p2p/p2p.gyp b/webrtc/p2p/p2p.gyp
new file mode 100644
index 0000000..102e75b
--- /dev/null
+++ b/webrtc/p2p/p2p.gyp
@@ -0,0 +1,130 @@
+# Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
+#
+# Use of this source code is governed by a BSD-style license
+# that can be found in the LICENSE file in the root of the source
+# tree. An additional intellectual property rights grant can be found
+# in the file PATENTS.  All contributing project authors may
+# be found in the AUTHORS file in the root of the source tree.
+
+{
+  'includes': [ '../build/common.gypi', ],
+  'targets': [
+    {
+      'target_name': 'rtc_p2p',
+      'type': 'static_library',
+      'dependencies': [
+        '<(webrtc_root)/base/base.gyp:webrtc_base',
+        '<(webrtc_root)/libjingle/xmpp/xmpp.gyp:rtc_xmpp',
+        '<(DEPTH)/third_party/expat/expat.gyp:expat',
+      ],
+      'cflags_cc!': [
+        '-Wnon-virtual-dtor',
+      ],
+      'export_dependent_settings': [
+        '<(DEPTH)/third_party/expat/expat.gyp:expat',
+      ],
+      'sources': [
+        'base/asyncstuntcpsocket.cc',
+        'base/asyncstuntcpsocket.h',
+        'base/basicpacketsocketfactory.cc',
+        'base/basicpacketsocketfactory.h',
+        'base/candidate.h',
+        'base/common.h',
+        'base/constants.cc',
+        'base/constants.h',
+        'base/dtlstransportchannel.cc',
+        'base/dtlstransportchannel.h',
+        'base/p2ptransport.cc',
+        'base/p2ptransport.h',
+        'base/p2ptransportchannel.cc',
+        'base/p2ptransportchannel.h',
+        'base/packetsocketfactory.h',
+        'base/parsing.cc',
+        'base/parsing.h',
+        'base/port.cc',
+        'base/port.h',
+        'base/portallocator.cc',
+        'base/portallocator.h',
+        'base/portallocatorsessionproxy.cc',
+        'base/portallocatorsessionproxy.h',
+        'base/portinterface.h',
+        'base/portproxy.cc',
+        'base/portproxy.h',
+        'base/pseudotcp.cc',
+        'base/pseudotcp.h',
+        'base/rawtransport.cc',
+        'base/rawtransport.h',
+        'base/rawtransportchannel.cc',
+        'base/rawtransportchannel.h',
+        'base/relayport.cc',
+        'base/relayport.h',
+        'base/relayserver.cc',
+        'base/relayserver.h',
+        'base/session.cc',
+        'base/session.h',
+        'base/sessionclient.h',
+        'base/sessiondescription.cc',
+        'base/sessiondescription.h',
+        'base/sessionid.h',
+        'base/sessionmanager.cc',
+        'base/sessionmanager.h',
+        'base/sessionmessages.cc',
+        'base/sessionmessages.h',
+        'base/stun.cc',
+        'base/stun.h',
+        'base/stunport.cc',
+        'base/stunport.h',
+        'base/stunrequest.cc',
+        'base/stunrequest.h',
+        'base/stunserver.cc',
+        'base/stunserver.h',
+        'base/tcpport.cc',
+        'base/tcpport.h',
+        'base/transport.cc',
+        'base/transport.h',
+        'base/transportchannel.cc',
+        'base/transportchannel.h',
+        'base/transportchannelimpl.h',
+        'base/transportchannelproxy.cc',
+        'base/transportchannelproxy.h',
+        'base/transportdescription.cc',
+        'base/transportdescription.h',
+        'base/transportdescriptionfactory.cc',
+        'base/transportdescriptionfactory.h',
+        'base/transportinfo.h',
+        'base/turnport.cc',
+        'base/turnport.h',
+        'base/turnserver.cc',
+        'base/turnserver.h',
+        'base/udpport.h',
+        'client/autoportallocator.h',
+        'client/basicportallocator.cc',
+        'client/basicportallocator.h',
+        'client/connectivitychecker.cc',
+        'client/connectivitychecker.h',
+        'client/httpportallocator.cc',
+        'client/httpportallocator.h',
+        'client/sessionmanagertask.h',
+        'client/sessionsendtask.h',
+        'client/socketmonitor.cc',
+        'client/socketmonitor.h',
+      ],
+      'direct_dependent_settings': {
+        'cflags_cc!': [
+          '-Wnon-virtual-dtor',
+        ],
+        'defines': [
+          'FEATURE_ENABLE_VOICEMAIL',
+        ],
+      },
+      'conditions': [
+        ['build_with_chromium==0', {
+          'defines': [
+            'FEATURE_ENABLE_VOICEMAIL',
+            'FEATURE_ENABLE_PSTN',
+          ],
+        }],
+      ],
+    }],
+}
+  
diff --git a/webrtc/p2p/p2p_tests.gypi b/webrtc/p2p/p2p_tests.gypi
new file mode 100644
index 0000000..f9e6959
--- /dev/null
+++ b/webrtc/p2p/p2p_tests.gypi
@@ -0,0 +1,44 @@
+# Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
+#
+# Use of this source code is governed by a BSD-style license
+# that can be found in the LICENSE file in the root of the source
+# tree. An additional intellectual property rights grant can be found
+# in the file PATENTS.  All contributing project authors may
+# be found in the AUTHORS file in the root of the source tree.
+
+{
+  'includes': [ '../build/common.gypi', ],
+  'targets': [
+    {
+      'target_name': 'rtc_p2p_unittest',
+      'type': 'none',
+      'direct_dependent_settings': {
+        'sources': [
+          'base/dtlstransportchannel_unittest.cc',
+          'base/fakesession.h',
+          'base/p2ptransportchannel_unittest.cc',
+          'base/port_unittest.cc',
+          'base/portallocatorsessionproxy_unittest.cc',
+          'base/pseudotcp_unittest.cc',
+          'base/relayport_unittest.cc',
+          'base/relayserver_unittest.cc',
+          'base/session_unittest.cc',
+          'base/stun_unittest.cc',
+          'base/stunport_unittest.cc',
+          'base/stunrequest_unittest.cc',
+          'base/stunserver_unittest.cc',
+          'base/testrelayserver.h',
+          'base/teststunserver.h',
+          'base/testturnserver.h',
+          'base/transport_unittest.cc',
+          'base/transportdescriptionfactory_unittest.cc',
+          'base/turnport_unittest.cc',
+          'client/connectivitychecker_unittest.cc',
+          'client/fakeportallocator.h',
+          'client/portallocator_unittest.cc',
+        ],
+      },
+    },
+  ],
+}
+