diff --git a/pc/rtc_stats_collector.cc b/pc/rtc_stats_collector.cc
index 569312c..464e22c 100644
--- a/pc/rtc_stats_collector.cc
+++ b/pc/rtc_stats_collector.cc
@@ -114,19 +114,23 @@
   return sb.str();
 }
 
-std::string RTCInboundRTPStreamStatsIDFromSSRC(cricket::MediaType media_type,
+std::string RTCInboundRTPStreamStatsIDFromSSRC(const std::string& transport_id,
+                                               cricket::MediaType media_type,
                                                uint32_t ssrc) {
   char buf[1024];
   rtc::SimpleStringBuilder sb(buf);
-  sb << 'I' << (media_type == cricket::MEDIA_TYPE_AUDIO ? 'A' : 'V') << ssrc;
+  sb << 'I' << transport_id
+     << (media_type == cricket::MEDIA_TYPE_AUDIO ? 'A' : 'V') << ssrc;
   return sb.str();
 }
 
-std::string RTCOutboundRTPStreamStatsIDFromSSRC(cricket::MediaType media_type,
+std::string RTCOutboundRTPStreamStatsIDFromSSRC(const std::string& transport_id,
+                                                cricket::MediaType media_type,
                                                 uint32_t ssrc) {
   char buf[1024];
   rtc::SimpleStringBuilder sb(buf);
-  sb << 'O' << (media_type == cricket::MEDIA_TYPE_AUDIO ? 'A' : 'V') << ssrc;
+  sb << 'O' << transport_id
+     << (media_type == cricket::MEDIA_TYPE_AUDIO ? 'A' : 'V') << ssrc;
   return sb.str();
 }
 
@@ -425,8 +429,8 @@
     const std::string& mid,
     int64_t timestamp_us) {
   auto inbound_audio = std::make_unique<RTCInboundRTPStreamStats>(
-      /*id=*/RTCInboundRTPStreamStatsIDFromSSRC(cricket::MEDIA_TYPE_AUDIO,
-                                                voice_receiver_info.ssrc()),
+      /*id=*/RTCInboundRTPStreamStatsIDFromSSRC(
+          transport_id, cricket::MEDIA_TYPE_AUDIO, voice_receiver_info.ssrc()),
       timestamp_us);
   SetInboundRTPStreamStatsFromMediaReceiverInfo(voice_receiver_info,
                                                 inbound_audio.get());
@@ -740,6 +744,7 @@
 
 std::unique_ptr<RTCRemoteInboundRtpStreamStats>
 ProduceRemoteInboundRtpStreamStatsFromReportBlockData(
+    const std::string& transport_id,
     const ReportBlockData& report_block_data,
     cricket::MediaType media_type,
     const std::map<std::string, RTCOutboundRTPStreamStats*>& outbound_rtps,
@@ -767,8 +772,8 @@
   remote_inbound->round_trip_time_measurements =
       report_block_data.num_rtts();
 
-  std::string local_id =
-      RTCOutboundRTPStreamStatsIDFromSSRC(media_type, report_block.source_ssrc);
+  std::string local_id = RTCOutboundRTPStreamStatsIDFromSSRC(
+      transport_id, media_type, report_block.source_ssrc);
   // Look up local stat from `outbound_rtps` where the pointers are non-const.
   auto local_id_it = outbound_rtps.find(local_id);
   if (local_id_it != outbound_rtps.end()) {
@@ -777,9 +782,7 @@
     outbound_rtp.remote_id = remote_inbound->id();
     // The RTP/RTCP transport is obtained from the
     // RTCOutboundRtpStreamStats's transport.
-    const auto* transport_from_id = outbound_rtp.transport_id.is_defined()
-                                        ? report.Get(*outbound_rtp.transport_id)
-                                        : nullptr;
+    const auto* transport_from_id = report.Get(transport_id);
     if (transport_from_id) {
       const auto& transport = transport_from_id->cast_to<RTCTransportStats>();
       // If RTP and RTCP are not multiplexed, there is a separate RTCP
@@ -2050,8 +2053,8 @@
     if (!voice_sender_info.connected())
       continue;
     auto outbound_audio = std::make_unique<RTCOutboundRTPStreamStats>(
-        RTCOutboundRTPStreamStatsIDFromSSRC(cricket::MEDIA_TYPE_AUDIO,
-                                            voice_sender_info.ssrc()),
+        RTCOutboundRTPStreamStatsIDFromSSRC(
+            transport_id, cricket::MEDIA_TYPE_AUDIO, voice_sender_info.ssrc()),
         timestamp_us);
     SetOutboundRTPStreamStatsFromVoiceSenderInfo(
         transport_id, mid,
@@ -2088,8 +2091,8 @@
        stats.track_media_info_map.voice_media_info()->senders) {
     for (const auto& report_block_data : voice_sender_info.report_block_datas) {
       report->AddStats(ProduceRemoteInboundRtpStreamStatsFromReportBlockData(
-          report_block_data, cricket::MEDIA_TYPE_AUDIO, audio_outbound_rtps,
-          *report));
+          transport_id, report_block_data, cricket::MEDIA_TYPE_AUDIO,
+          audio_outbound_rtps, *report));
     }
   }
 }
@@ -2114,7 +2117,8 @@
     if (!video_receiver_info.connected())
       continue;
     auto inbound_video = std::make_unique<RTCInboundRTPStreamStats>(
-        RTCInboundRTPStreamStatsIDFromSSRC(cricket::MEDIA_TYPE_VIDEO,
+        RTCInboundRTPStreamStatsIDFromSSRC(transport_id,
+                                           cricket::MEDIA_TYPE_VIDEO,
                                            video_receiver_info.ssrc()),
         timestamp_us);
     SetInboundRTPStreamStatsFromVideoReceiverInfo(
@@ -2143,8 +2147,8 @@
     if (!video_sender_info.connected())
       continue;
     auto outbound_video = std::make_unique<RTCOutboundRTPStreamStats>(
-        RTCOutboundRTPStreamStatsIDFromSSRC(cricket::MEDIA_TYPE_VIDEO,
-                                            video_sender_info.ssrc()),
+        RTCOutboundRTPStreamStatsIDFromSSRC(
+            transport_id, cricket::MEDIA_TYPE_VIDEO, video_sender_info.ssrc()),
         timestamp_us);
     SetOutboundRTPStreamStatsFromVideoSenderInfo(
         transport_id, mid,
@@ -2181,8 +2185,8 @@
        stats.track_media_info_map.video_media_info()->senders) {
     for (const auto& report_block_data : video_sender_info.report_block_datas) {
       report->AddStats(ProduceRemoteInboundRtpStreamStatsFromReportBlockData(
-          report_block_data, cricket::MEDIA_TYPE_VIDEO, video_outbound_rtps,
-          *report));
+          transport_id, report_block_data, cricket::MEDIA_TYPE_VIDEO,
+          video_outbound_rtps, *report));
     }
   }
 }
diff --git a/pc/rtc_stats_collector_unittest.cc b/pc/rtc_stats_collector_unittest.cc
index 8ffdf72..9d7ae24 100644
--- a/pc/rtc_stats_collector_unittest.cc
+++ b/pc/rtc_stats_collector_unittest.cc
@@ -720,7 +720,7 @@
     video_media_info.receive_codecs.insert(
         std::make_pair(recv_codec.payload_type, recv_codec));
     // outbound-rtp
-    graph.outbound_rtp_id = "OV3";
+    graph.outbound_rtp_id = "OTTransportName1V3";
     video_media_info.senders.push_back(cricket::VideoSenderInfo());
     video_media_info.senders[0].local_stats.push_back(
         cricket::SsrcSenderInfo());
@@ -728,7 +728,7 @@
     video_media_info.senders[0].codec_payload_type = send_codec.payload_type;
     video_media_info.aggregated_senders.push_back(video_media_info.senders[0]);
     // inbound-rtp
-    graph.inbound_rtp_id = "IV4";
+    graph.inbound_rtp_id = "ITTransportName1V4";
     video_media_info.receivers.push_back(cricket::VideoReceiverInfo());
     video_media_info.receivers[0].local_stats.push_back(
         cricket::SsrcReceiverInfo());
@@ -820,13 +820,13 @@
     media_info.receive_codecs.insert(
         std::make_pair(recv_codec.payload_type, recv_codec));
     // outbound-rtp
-    graph.outbound_rtp_id = "OA3";
+    graph.outbound_rtp_id = "OTTransportName1A3";
     media_info.senders.push_back(cricket::VoiceSenderInfo());
     media_info.senders[0].local_stats.push_back(cricket::SsrcSenderInfo());
     media_info.senders[0].local_stats[0].ssrc = kLocalSsrc;
     media_info.senders[0].codec_payload_type = send_codec.payload_type;
     // inbound-rtp
-    graph.inbound_rtp_id = "IA4";
+    graph.inbound_rtp_id = "ITTransportName1A4";
     media_info.receivers.push_back(cricket::VoiceReceiverInfo());
     media_info.receivers[0].local_stats.push_back(cricket::SsrcReceiverInfo());
     media_info.receivers[0].local_stats[0].ssrc = kRemoteSsrc;
@@ -1043,10 +1043,8 @@
   rtc::scoped_refptr<const RTCStatsReport> report = stats_->GetStatsReport();
   auto inbound_rtps = report->GetStatsOfType<RTCInboundRTPStreamStats>();
   auto outbound_rtps = report->GetStatsOfType<RTCOutboundRTPStreamStats>();
-  // TODO(https://crbug.com/webrtc/14443): When valid SSRC collisions are
-  // handled correctly, we should expect to see 4 of each type of object here.
-  EXPECT_EQ(inbound_rtps.size(), 2u);
-  EXPECT_EQ(outbound_rtps.size(), 2u);
+  EXPECT_EQ(inbound_rtps.size(), 4u);
+  EXPECT_EQ(outbound_rtps.size(), 4u);
 }
 
 // These SSRC collisions are illegal, so it is not clear if this setup can
@@ -2259,7 +2257,8 @@
   auto stats_of_track_type = report->GetStatsOfType<RTCMediaStreamTrackStats>();
   ASSERT_EQ(1U, stats_of_track_type.size());
 
-  RTCInboundRTPStreamStats expected_audio("IA1", report->timestamp_us());
+  RTCInboundRTPStreamStats expected_audio("ITTransportName1A1",
+                                          report->timestamp_us());
   expected_audio.ssrc = 1;
   expected_audio.media_type = "audio";
   expected_audio.kind = "audio";
@@ -2378,7 +2377,8 @@
 
   rtc::scoped_refptr<const RTCStatsReport> report = stats_->GetStatsReport();
 
-  RTCInboundRTPStreamStats expected_video("IV1", report->timestamp_us());
+  RTCInboundRTPStreamStats expected_video("ITTransportName1V1",
+                                          report->timestamp_us());
   expected_video.ssrc = 1;
   expected_video.media_type = "video";
   expected_video.kind = "video";
@@ -2476,7 +2476,8 @@
 
   rtc::scoped_refptr<const RTCStatsReport> report = stats_->GetStatsReport();
 
-  RTCOutboundRTPStreamStats expected_audio("OA1", report->timestamp_us());
+  RTCOutboundRTPStreamStats expected_audio("OTTransportName1A1",
+                                           report->timestamp_us());
   expected_audio.media_source_id = "SA50";
   // `expected_audio.remote_id` should be undefined.
   expected_audio.mid = "AudioMid";
@@ -2906,7 +2907,8 @@
 
   rtc::scoped_refptr<const RTCStatsReport> report = stats_->GetStatsReport();
 
-  RTCOutboundRTPStreamStats expected_audio("OA1", report->timestamp_us());
+  RTCOutboundRTPStreamStats expected_audio("OTTransportName1A1",
+                                           report->timestamp_us());
   expected_audio.media_source_id = "SA50";
   expected_audio.mid = "AudioMid";
   expected_audio.ssrc = 1;
@@ -3234,7 +3236,8 @@
         "TTransportName1";  // 1 for RTP (we have no RTCP
                             // transport)
     expected_remote_inbound_rtp.packets_lost = 7;
-    expected_remote_inbound_rtp.local_id = "O" + MediaTypeCharStr() + stream_id;
+    expected_remote_inbound_rtp.local_id =
+        "OTTransportName1" + MediaTypeCharStr() + stream_id;
     expected_remote_inbound_rtp.round_trip_time = kRoundTripTimeSample2Seconds;
     expected_remote_inbound_rtp.total_round_trip_time =
         kRoundTripTimeSample1Seconds + kRoundTripTimeSample2Seconds;