diff --git a/api/video_codecs/video_codec.h b/api/video_codecs/video_codec.h
index 828bd1d..57bb893 100644
--- a/api/video_codecs/video_codec.h
+++ b/api/video_codecs/video_codec.h
@@ -82,6 +82,7 @@
   }
   bool frameDroppingOn;
   int keyFrameInterval;
+  uint8_t numberOfTemporalLayers;
   // These are NULL/0 if not externally negotiated.
   const uint8_t* spsData;
   size_t spsLen;
diff --git a/api/video_codecs/video_encoder.cc b/api/video_codecs/video_encoder.cc
index 5b7d89c..e56c597 100644
--- a/api/video_codecs/video_encoder.cc
+++ b/api/video_codecs/video_encoder.cc
@@ -53,6 +53,7 @@
 
   h264_settings.frameDroppingOn = true;
   h264_settings.keyFrameInterval = 3000;
+  h264_settings.numberOfTemporalLayers = 1;
   h264_settings.spsData = nullptr;
   h264_settings.spsLen = 0;
   h264_settings.ppsData = nullptr;
diff --git a/call/rtp_payload_params.cc b/call/rtp_payload_params.cc
index 93ef654..6042ed3 100644
--- a/call/rtp_payload_params.cc
+++ b/call/rtp_payload_params.cc
@@ -91,6 +91,15 @@
       h264_header.packetization_mode =
           info.codecSpecific.H264.packetization_mode;
       rtp->simulcastIdx = spatial_index.value_or(0);
+      rtp->frame_marking.temporal_id = kNoTemporalIdx;
+      if (info.codecSpecific.H264.temporal_idx != kNoTemporalIdx) {
+        rtp->frame_marking.temporal_id = info.codecSpecific.H264.temporal_idx;
+        rtp->frame_marking.layer_id = 0;
+        rtp->frame_marking.independent_frame =
+            info.codecSpecific.H264.idr_frame;
+        rtp->frame_marking.base_layer_sync =
+            info.codecSpecific.H264.base_layer_sync;
+      }
       return;
     }
     case kVideoCodecMultiplex:
@@ -222,6 +231,14 @@
       vp9_header.tl0_pic_idx = state_.tl0_pic_idx;
     }
   }
+  if (rtp_video_header->codec == kVideoCodecH264) {
+    if (rtp_video_header->frame_marking.temporal_id != kNoTemporalIdx) {
+      if (rtp_video_header->frame_marking.temporal_id == 0) {
+        ++state_.tl0_pic_idx;
+      }
+      rtp_video_header->frame_marking.tl0_pic_idx = state_.tl0_pic_idx;
+    }
+  }
   // There are currently two generic descriptors in WebRTC. The old descriptor
   // can not share a picture id space between simulcast streams, so we use the
   // |picture_id| in this case. We let the |picture_id| tag along in |frame_id|
diff --git a/call/rtp_payload_params_unittest.cc b/call/rtp_payload_params_unittest.cc
index c46d975..ff3589e 100644
--- a/call/rtp_payload_params_unittest.cc
+++ b/call/rtp_payload_params_unittest.cc
@@ -144,14 +144,18 @@
 }
 
 TEST(RtpPayloadParamsTest, InfoMappedToRtpVideoHeader_H264) {
-  RtpPayloadParams params(kSsrc1, {});
+  RtpPayloadState state;
+  state.picture_id = kPictureId;
+  state.tl0_pic_idx = kInitialTl0PicIdx1;
+  RtpPayloadParams params(kSsrc1, &state);
 
   EncodedImage encoded_image;
   CodecSpecificInfo codec_info;
+  CodecSpecificInfoH264 *h264info = &codec_info.codecSpecific.H264;
   memset(&codec_info, 0, sizeof(CodecSpecificInfo));
   codec_info.codecType = kVideoCodecH264;
-  codec_info.codecSpecific.H264.packetization_mode =
-      H264PacketizationMode::SingleNalUnit;
+  h264info->packetization_mode = H264PacketizationMode::SingleNalUnit;
+  h264info->temporal_idx = kNoTemporalIdx;
 
   RTPVideoHeader header =
       params.GetRtpVideoHeader(encoded_image, &codec_info, kDontCare);
@@ -160,6 +164,32 @@
   EXPECT_EQ(kVideoCodecH264, header.codec);
   const auto& h264 = absl::get<RTPVideoHeaderH264>(header.video_type_header);
   EXPECT_EQ(H264PacketizationMode::SingleNalUnit, h264.packetization_mode);
+
+  // test temporal param 1
+  h264info->temporal_idx = 1;
+  h264info->base_layer_sync = true;
+  h264info->idr_frame = false;
+
+  header = params.GetRtpVideoHeader(encoded_image, &codec_info, kDontCare);
+
+  EXPECT_EQ(kVideoCodecH264, header.codec);
+  EXPECT_EQ(header.frame_marking.tl0_pic_idx, kInitialTl0PicIdx1);
+  EXPECT_EQ(header.frame_marking.temporal_id, h264info->temporal_idx);
+  EXPECT_EQ(header.frame_marking.base_layer_sync, h264info->base_layer_sync);
+  EXPECT_EQ(header.frame_marking.independent_frame, h264info->idr_frame);
+
+  // test temporal param 2
+  h264info->temporal_idx = 0;
+  h264info->base_layer_sync = false;
+  h264info->idr_frame = true;
+
+  header = params.GetRtpVideoHeader(encoded_image, &codec_info, kDontCare);
+
+  EXPECT_EQ(kVideoCodecH264, header.codec);
+  EXPECT_EQ(header.frame_marking.tl0_pic_idx, kInitialTl0PicIdx1 + 1);
+  EXPECT_EQ(header.frame_marking.temporal_id, h264info->temporal_idx);
+  EXPECT_EQ(header.frame_marking.base_layer_sync, h264info->base_layer_sync);
+  EXPECT_EQ(header.frame_marking.independent_frame, h264info->idr_frame);
 }
 
 TEST(RtpPayloadParamsTest, PictureIdIsSetForVp8) {
diff --git a/media/engine/fake_webrtc_call.cc b/media/engine/fake_webrtc_call.cc
index 4dd3b39b..662c6d2 100644
--- a/media/engine/fake_webrtc_call.cc
+++ b/media/engine/fake_webrtc_call.cc
@@ -249,6 +249,8 @@
     } else if (config_.rtp.payload_name == "H264") {
       config.encoder_specific_settings->FillVideoCodecH264(
           &codec_specific_settings_.h264);
+      codec_specific_settings_.h264.numberOfTemporalLayers =
+            num_temporal_layers;
     } else {
       ADD_FAILURE() << "Unsupported encoder payload: "
                     << config_.rtp.payload_name;
diff --git a/media/engine/webrtc_video_engine.cc b/media/engine/webrtc_video_engine.cc
index 88f9000..e001872 100644
--- a/media/engine/webrtc_video_engine.cc
+++ b/media/engine/webrtc_video_engine.cc
@@ -2690,7 +2690,8 @@
         absl::EqualsIgnoreCase(codec_name_, kH264CodecName)) &&
        is_screenshare_ && screenshare_config_explicitly_enabled_)) {
     const bool temporal_layers_supported =
-        absl::EqualsIgnoreCase(codec_name_, kVp8CodecName);
+        absl::EqualsIgnoreCase(codec_name_, kVp8CodecName)
+        || absl::EqualsIgnoreCase(codec_name_, kH264CodecName);
     layers = GetSimulcastConfig(encoder_config.number_of_streams, width, height,
                                 0 /*not used*/, encoder_config.bitrate_priority,
                                 max_qp_, 0 /*not_used*/, is_screenshare_,
diff --git a/modules/rtp_rtcp/source/rtp_sender_video.cc b/modules/rtp_rtcp/source/rtp_sender_video.cc
index c63f0d7..3adc98a 100644
--- a/modules/rtp_rtcp/source/rtp_sender_video.cc
+++ b/modules/rtp_rtcp/source/rtp_sender_video.cc
@@ -58,6 +58,7 @@
                             FrameType frame_type,
                             bool set_video_rotation,
                             bool set_color_space,
+                            bool set_frame_marking,
                             bool first_packet,
                             bool last_packet,
                             RtpPacketToSend* packet) {
@@ -84,6 +85,14 @@
   if (playout_delay) {
     packet->SetExtension<PlayoutDelayLimits>(*playout_delay);
   }
+
+  if (set_frame_marking) {
+    FrameMarking frame_marking = video_header.frame_marking;
+    frame_marking.start_of_frame = first_packet;
+    frame_marking.end_of_frame = last_packet;
+    packet->SetExtension<FrameMarkingExtension>(frame_marking);
+  }
+
   if (video_header.generic) {
     RtpGenericFrameDescriptor generic_descriptor;
     generic_descriptor.SetFirstPacketInSubFrame(first_packet);
@@ -215,6 +224,12 @@
 
   rtc::CritScope cs(&payload_type_crit_);
   payload_type_map_[payload_type] = video_type;
+
+  // Backward compatibility for older receivers without temporal layer logic
+  if (video_type == kVideoCodecH264) {
+    rtc::CritScope cs(&crit_);
+    retransmission_settings_ = kRetransmitBaseLayer | kRetransmitHigherLayers;
+  }
 }
 
 void RTPSenderVideo::SendVideoPacket(std::unique_ptr<RtpPacketToSend> packet,
@@ -422,6 +437,8 @@
   int32_t retransmission_settings;
   bool set_video_rotation;
   bool set_color_space = false;
+  bool set_frame_marking = video_header->codec == kVideoCodecH264 &&
+        video_header->frame_marking.temporal_id != kNoTemporalIdx;
 
   const absl::optional<PlayoutDelay> playout_delay =
       playout_delay_oracle_.PlayoutDelayToSend(video_header->playout_delay);
@@ -489,17 +506,18 @@
   auto last_packet = absl::make_unique<RtpPacketToSend>(*single_packet);
   // Simplest way to estimate how much extensions would occupy is to set them.
   AddRtpHeaderExtensions(*video_header, playout_delay, frame_type,
-                         set_video_rotation, set_color_space, /*first=*/true,
-                         /*last=*/true, single_packet.get());
+                         set_video_rotation, set_color_space, set_frame_marking,
+                         /*first=*/true, /*last=*/true, single_packet.get());
   AddRtpHeaderExtensions(*video_header, playout_delay, frame_type,
-                         set_video_rotation, set_color_space, /*first=*/true,
-                         /*last=*/false, first_packet.get());
+                         set_video_rotation, set_color_space, set_frame_marking,
+                         /*first=*/true, /*last=*/false, first_packet.get());
   AddRtpHeaderExtensions(*video_header, playout_delay, frame_type,
-                         set_video_rotation, set_color_space, /*first=*/false,
-                         /*last=*/false, middle_packet.get());
+                         set_video_rotation, set_color_space, set_frame_marking,
+                         /*first=*/false, /*last=*/false, middle_packet.get());
   AddRtpHeaderExtensions(*video_header, playout_delay, frame_type,
-                         set_video_rotation, set_color_space, /*first=*/false,
-                         /*last=*/true, last_packet.get());
+                         set_video_rotation, set_color_space, set_frame_marking,
+                         /*first=*/false, /*last=*/true, last_packet.get());
+
   RTC_DCHECK_GT(packet_capacity, single_packet->headers_size());
   RTC_DCHECK_GT(packet_capacity, first_packet->headers_size());
   RTC_DCHECK_GT(packet_capacity, middle_packet->headers_size());
@@ -733,7 +751,12 @@
     uint8_t operator()(const RTPVideoHeaderH264&) { return kNoTemporalIdx; }
     uint8_t operator()(const absl::monostate&) { return kNoTemporalIdx; }
   };
-  return absl::visit(TemporalIdGetter(), header.video_type_header);
+  switch (header.codec) {
+    case kVideoCodecH264:
+      return header.frame_marking.temporal_id;
+    default:
+      return absl::visit(TemporalIdGetter(), header.video_type_header);
+  }
 }
 
 bool RTPSenderVideo::UpdateConditionalRetransmit(
diff --git a/modules/rtp_rtcp/source/rtp_sender_video_unittest.cc b/modules/rtp_rtcp/source/rtp_sender_video_unittest.cc
index 85bbc80..43eb4ed 100644
--- a/modules/rtp_rtcp/source/rtp_sender_video_unittest.cc
+++ b/modules/rtp_rtcp/source/rtp_sender_video_unittest.cc
@@ -39,6 +39,7 @@
 constexpr int kTransportSequenceNumberExtensionId = 13;
 constexpr int kVideoTimingExtensionId = 12;
 constexpr int kGenericDescriptorId = 10;
+constexpr int kFrameMarkingExtensionId = 6;
 constexpr int kVideoRotationExtensionId = 5;
 constexpr int kPayload = 100;
 constexpr uint32_t kTimestamp = 10;
@@ -63,6 +64,8 @@
                                    kVideoTimingExtensionId);
     receivers_extensions_.Register(kRtpExtensionGenericFrameDescriptor,
                                    kGenericDescriptorId);
+    receivers_extensions_.Register(kRtpExtensionFrameMarking,
+                                   kFrameMarkingExtensionId);
   }
 
   bool SendRtp(const uint8_t* data,
@@ -230,6 +233,43 @@
   EXPECT_EQ(kVideoRotation_90, rotation);
 }
 
+TEST_P(RtpSenderVideoTest, CheckH264FrameMarking) {
+  uint8_t kFrame[kMaxPacketLength];
+  EXPECT_EQ(0, rtp_sender_.RegisterRtpHeaderExtension(
+                   kRtpExtensionFrameMarking, kFrameMarkingExtensionId));
+
+  RTPFragmentationHeader frag;
+  frag.VerifyAndAllocateFragmentationHeader(1);
+  frag.fragmentationOffset[0] = 0;
+  frag.fragmentationLength[0] = sizeof(kFrame);
+
+  RTPVideoHeader hdr;
+  hdr.video_type_header.emplace<RTPVideoHeaderH264>().packetization_mode =
+      H264PacketizationMode::NonInterleaved;
+  hdr.codec = kVideoCodecH264;
+  hdr.frame_marking.temporal_id = kNoTemporalIdx;
+  hdr.frame_marking.tl0_pic_idx = 99;
+  hdr.frame_marking.base_layer_sync = true;
+  rtp_sender_video_.SendVideo(kVideoFrameDelta, kPayload,
+                               kTimestamp, 0, kFrame, sizeof(kFrame), &frag,
+                               &hdr, kDefaultExpectedRetransmissionTimeMs);
+
+  FrameMarking fm;
+  EXPECT_FALSE(
+      transport_.last_sent_packet().GetExtension<FrameMarkingExtension>(&fm));
+
+  hdr.frame_marking.temporal_id = 0;
+  rtp_sender_video_.SendVideo(kVideoFrameDelta, kPayload,
+                               kTimestamp + 1, 0, kFrame, sizeof(kFrame), &frag,
+                               &hdr, kDefaultExpectedRetransmissionTimeMs);
+
+  EXPECT_TRUE(
+      transport_.last_sent_packet().GetExtension<FrameMarkingExtension>(&fm));
+  EXPECT_EQ(hdr.frame_marking.temporal_id, fm.temporal_id);
+  EXPECT_EQ(hdr.frame_marking.tl0_pic_idx, fm.tl0_pic_idx);
+  EXPECT_EQ(hdr.frame_marking.base_layer_sync, fm.base_layer_sync);
+}
+
 // Make sure rotation is parsed correctly when the Camera (C) and Flip (F) bits
 // are set in the CVO byte.
 TEST_P(RtpSenderVideoTest, SendVideoWithCameraAndFlipCVO) {
@@ -275,6 +315,7 @@
   header.video_type_header.emplace<RTPVideoHeaderH264>().packetization_mode =
       H264PacketizationMode::NonInterleaved;
   header.codec = kVideoCodecH264;
+  header.frame_marking.temporal_id = kNoTemporalIdx;
 
   EXPECT_EQ(kDontRetransmit,
             rtp_sender_video_.GetStorageType(
@@ -289,6 +330,15 @@
             rtp_sender_video_.GetStorageType(
                 header, kConditionallyRetransmitHigherLayers,
                 kDefaultExpectedRetransmissionTimeMs));
+
+  // Test higher level retransmit.
+  for (int tid = 0; tid <= kMaxTemporalStreams; ++tid) {
+    header.frame_marking.temporal_id = tid;
+    EXPECT_EQ(kAllowRetransmission,
+              rtp_sender_video_.GetStorageType(
+                  header, kRetransmitHigherLayers | kRetransmitBaseLayer,
+                  kDefaultExpectedRetransmissionTimeMs));
+  }
 }
 
 TEST_P(RtpSenderVideoTest, RetransmissionTypesVP8BaseLayer) {
diff --git a/modules/rtp_rtcp/source/rtp_video_header.h b/modules/rtp_rtcp/source/rtp_video_header.h
index b6c43ef..49d8c28 100644
--- a/modules/rtp_rtcp/source/rtp_video_header.h
+++ b/modules/rtp_rtcp/source/rtp_video_header.h
@@ -63,7 +63,7 @@
 
   PlayoutDelay playout_delay = {-1, -1};
   VideoSendTiming video_timing;
-  FrameMarking frame_marking;
+  FrameMarking frame_marking = {false, false, false, false, false, 0xFF, 0, 0};
   absl::optional<ColorSpace> color_space;
   RTPVideoTypeHeader video_type_header;
 };
diff --git a/modules/video_coding/codecs/h264/h264_encoder_impl.cc b/modules/video_coding/codecs/h264/h264_encoder_impl.cc
index 7aeac66..7e9464c 100644
--- a/modules/video_coding/codecs/h264/h264_encoder_impl.cc
+++ b/modules/video_coding/codecs/h264/h264_encoder_impl.cc
@@ -167,7 +167,9 @@
       number_of_cores_(0),
       encoded_image_callback_(nullptr),
       has_reported_init_(false),
-      has_reported_error_(false) {
+      has_reported_error_(false),
+      num_temporal_layers_(1),
+      tl0sync_limit_(0) {
   RTC_CHECK(absl::EqualsIgnoreCase(codec.name, cricket::kH264CodecName));
   std::string packetization_mode_string;
   if (codec.GetParam(cricket::kH264FmtpPacketizationMode,
@@ -236,13 +238,10 @@
     codec_.simulcastStream[0].height = codec_.height;
   }
 
+  num_temporal_layers_ = codec_.H264()->numberOfTemporalLayers;
+
   for (int i = 0, idx = number_of_streams - 1; i < number_of_streams;
        ++i, --idx) {
-    // Temporal layers still not supported.
-    if (inst->simulcastStream[i].numberOfTemporalLayers > 1) {
-      Release();
-      return WEBRTC_VIDEO_CODEC_ERR_SIMULCAST_PARAMETERS_NOT_SUPPORTED;
-    }
     ISVCEncoder* openh264_encoder;
     // Create encoder.
     if (WelsCreateSVCEncoder(&openh264_encoder) != 0) {
@@ -530,6 +529,22 @@
       codec_specific.codecType = kVideoCodecH264;
       codec_specific.codecSpecific.H264.packetization_mode =
           packetization_mode_;
+      codec_specific.codecSpecific.H264.temporal_idx = kNoTemporalIdx;
+      codec_specific.codecSpecific.H264.idr_frame =
+          info.eFrameType == videoFrameTypeIDR;
+      codec_specific.codecSpecific.H264.base_layer_sync = false;
+      if (num_temporal_layers_ > 1) {
+        const uint8_t tid = info.sLayerInfo[0].uiTemporalId;
+        codec_specific.codecSpecific.H264.temporal_idx = tid;
+        codec_specific.codecSpecific.H264.base_layer_sync =
+            tid > 0 && tid < tl0sync_limit_;
+        if (codec_specific.codecSpecific.H264.base_layer_sync) {
+          tl0sync_limit_ = tid;
+        }
+        if (tid == 0) {
+          tl0sync_limit_ = num_temporal_layers_;
+        }
+      }
       encoded_image_callback_->OnEncodedImage(encoded_images_[i],
                                               &codec_specific, &frag_header);
     }
@@ -581,6 +596,10 @@
       encoder_params.iTargetBitrate;
   encoder_params.sSpatialLayers[0].iMaxSpatialBitrate =
       encoder_params.iMaxBitrate;
+  encoder_params.iTemporalLayerNum = num_temporal_layers_;
+  if (encoder_params.iTemporalLayerNum > 1) {
+    encoder_params.iNumRefFrame = 1;
+  }
   RTC_LOG(INFO) << "OpenH264 version is " << OPENH264_MAJOR << "."
                 << OPENH264_MINOR;
   switch (packetization_mode_) {
diff --git a/modules/video_coding/codecs/h264/h264_encoder_impl.h b/modules/video_coding/codecs/h264/h264_encoder_impl.h
index da32563..044b6eb 100644
--- a/modules/video_coding/codecs/h264/h264_encoder_impl.h
+++ b/modules/video_coding/codecs/h264/h264_encoder_impl.h
@@ -100,6 +100,9 @@
 
   bool has_reported_init_;
   bool has_reported_error_;
+
+  int num_temporal_layers_;
+  uint8_t tl0sync_limit_;
 };
 
 }  // namespace webrtc
diff --git a/modules/video_coding/codecs/h264/include/h264_globals.h b/modules/video_coding/codecs/h264/include/h264_globals.h
index e321500..321a6b7 100644
--- a/modules/video_coding/codecs/h264/include/h264_globals.h
+++ b/modules/video_coding/codecs/h264/include/h264_globals.h
@@ -15,6 +15,8 @@
 #define MODULES_VIDEO_CODING_CODECS_H264_INCLUDE_H264_GLOBALS_H_
 
 #include <string>
+#include "modules/video_coding/codecs/interface/common_constants.h"
+
 
 #include "rtc_base/checks.h"
 
diff --git a/modules/video_coding/encoded_frame.cc b/modules/video_coding/encoded_frame.cc
index c18ef13..6e8e342 100644
--- a/modules/video_coding/encoded_frame.cc
+++ b/modules/video_coding/encoded_frame.cc
@@ -135,6 +135,20 @@
       }
       case kVideoCodecH264: {
         _codecSpecificInfo.codecType = kVideoCodecH264;
+
+        // The following H264 codec specific data are not used elsewhere.
+        // Instead they are read directly from the frame marking extension.
+        // These codec specific data structures should be removed
+        // when frame marking is used.
+        _codecSpecificInfo.codecSpecific.H264.temporal_idx = kNoTemporalIdx;
+        if (header->frame_marking.temporal_id != kNoTemporalIdx) {
+          _codecSpecificInfo.codecSpecific.H264.temporal_idx =
+              header->frame_marking.temporal_id;
+          _codecSpecificInfo.codecSpecific.H264.base_layer_sync =
+              header->frame_marking.base_layer_sync;
+          _codecSpecificInfo.codecSpecific.H264.idr_frame =
+              header->frame_marking.independent_frame;
+        }
         break;
       }
       default: {
diff --git a/modules/video_coding/include/video_codec_interface.h b/modules/video_coding/include/video_codec_interface.h
index 052963c..0a6c12d 100644
--- a/modules/video_coding/include/video_codec_interface.h
+++ b/modules/video_coding/include/video_codec_interface.h
@@ -83,6 +83,9 @@
 // Hack alert - the code assumes that thisstruct is memset when constructed.
 struct CodecSpecificInfoH264 {
   H264PacketizationMode packetization_mode;
+  uint8_t temporal_idx;
+  bool base_layer_sync;
+  bool idr_frame;
 };
 static_assert(std::is_pod<CodecSpecificInfoH264>::value, "");
 
diff --git a/modules/video_coding/session_info.cc b/modules/video_coding/session_info.cc
index d6b59be..f77f6d6 100644
--- a/modules/video_coding/session_info.cc
+++ b/modules/video_coding/session_info.cc
@@ -95,6 +95,8 @@
     return absl::get<RTPVideoHeaderVP9>(
                packets_.front().video_header.video_type_header)
         .temporal_idx;
+  } else if (packets_.front().video_header.codec == kVideoCodecH264) {
+    return packets_.front().video_header.frame_marking.temporal_id;
   } else {
     return kNoTemporalIdx;
   }
@@ -111,6 +113,8 @@
     return absl::get<RTPVideoHeaderVP9>(
                packets_.front().video_header.video_type_header)
         .temporal_up_switch;
+  } else if (packets_.front().video_header.codec == kVideoCodecH264) {
+    return packets_.front().video_header.frame_marking.base_layer_sync;
   } else {
     return false;
   }
@@ -127,6 +131,8 @@
     return absl::get<RTPVideoHeaderVP9>(
                packets_.front().video_header.video_type_header)
         .tl0_pic_idx;
+  } else if (packets_.front().video_header.codec == kVideoCodecH264) {
+    return packets_.front().video_header.frame_marking.tl0_pic_idx;
   } else {
     return kNoTl0PicIdx;
   }
diff --git a/modules/video_coding/video_codec_initializer.cc b/modules/video_coding/video_codec_initializer.cc
index d67cf52..a2bc27a 100644
--- a/modules/video_coding/video_codec_initializer.cc
+++ b/modules/video_coding/video_codec_initializer.cc
@@ -225,6 +225,12 @@
     case kVideoCodecH264: {
       if (!config.encoder_specific_settings)
         *video_codec.H264() = VideoEncoder::GetDefaultH264Settings();
+      video_codec.H264()->numberOfTemporalLayers = static_cast<unsigned char>(
+          streams.back().num_temporal_layers.value_or(
+              video_codec.H264()->numberOfTemporalLayers));
+      RTC_DCHECK_GE(video_codec.H264()->numberOfTemporalLayers, 1);
+      RTC_DCHECK_LE(video_codec.H264()->numberOfTemporalLayers,
+                    kMaxTemporalStreams);
       break;
     }
     default:
diff --git a/video/rtp_video_stream_receiver.cc b/video/rtp_video_stream_receiver.cc
index 2c35ceb..656dd7a 100644
--- a/video/rtp_video_stream_receiver.cc
+++ b/video/rtp_video_stream_receiver.cc
@@ -495,6 +495,8 @@
       VideoSendTiming::kInvalid;
   webrtc_rtp_header.video_header().is_last_packet_in_frame =
       webrtc_rtp_header.header.markerBit;
+  webrtc_rtp_header.video_header().frame_marking.temporal_id = kNoTemporalIdx;
+
   if (parsed_payload.video_header().codec == kVideoCodecVP9) {
     const RTPVideoHeaderVP9& codec_header = absl::get<RTPVideoHeaderVP9>(
         parsed_payload.video_header().video_type_header);
@@ -512,6 +514,9 @@
       &webrtc_rtp_header.video_header().video_timing);
   packet.GetExtension<PlayoutDelayLimits>(
       &webrtc_rtp_header.video_header().playout_delay);
+  packet.GetExtension<FrameMarkingExtension>(
+      &webrtc_rtp_header.video_header().frame_marking);
+
   webrtc_rtp_header.video_header().color_space =
       packet.GetExtension<ColorSpaceExtension>();
   if (webrtc_rtp_header.video_header().color_space ||
@@ -523,6 +528,7 @@
   } else if (last_color_space_) {
     webrtc_rtp_header.video_header().color_space = last_color_space_;
   }
+
   absl::optional<RtpGenericFrameDescriptor> generic_descriptor_wire;
   generic_descriptor_wire.emplace();
   if (packet.GetExtension<RtpGenericFrameDescriptorExtension>(
diff --git a/video/video_send_stream_tests.cc b/video/video_send_stream_tests.cc
index bd5a03c..057fd95 100644
--- a/video/video_send_stream_tests.cc
+++ b/video/video_send_stream_tests.cc
@@ -2534,8 +2534,23 @@
 template <>
 void VideoCodecConfigObserver<VideoCodecH264>::VerifyCodecSpecifics(
     const VideoCodec& config) const {
+  // Check that the number of temporal layers has propagated properly to
+  // VideoCodec.
+  EXPECT_EQ(kVideoCodecConfigObserverNumberOfTemporalLayers,
+            config.H264().numberOfTemporalLayers);
+
+  for (unsigned char i = 0; i < config.numberOfSimulcastStreams; ++i) {
+    EXPECT_EQ(kVideoCodecConfigObserverNumberOfTemporalLayers,
+              config.simulcastStream[i].numberOfTemporalLayers);
+  }
+
+  // Set expected temporal layers as they should have been set when
+  // reconfiguring the encoder and not match the set config.
+  VideoCodecH264 encoder_settings = encoder_settings_;
+  encoder_settings.numberOfTemporalLayers =
+      kVideoCodecConfigObserverNumberOfTemporalLayers;
   EXPECT_EQ(
-      0, memcmp(&config.H264(), &encoder_settings_, sizeof(encoder_settings_)));
+      0, memcmp(&config.H264(), &encoder_settings, sizeof(encoder_settings_)));
 }
 
 template <>
diff --git a/video/video_stream_encoder.cc b/video/video_stream_encoder.cc
index 168b267..fb9dd8b 100644
--- a/video/video_stream_encoder.cc
+++ b/video/video_stream_encoder.cc
@@ -628,6 +628,8 @@
     num_layers = codec.VP8()->numberOfTemporalLayers;
   } else if (codec.codecType == kVideoCodecVP9) {
     num_layers = codec.VP9()->numberOfTemporalLayers;
+  } else if (codec.codecType == kVideoCodecH264) {
+    num_layers = codec.H264()->numberOfTemporalLayers;
   } else if (codec.codecType == kVideoCodecGeneric &&
              codec.numberOfSimulcastStreams > 0) {
     // This is mainly for unit testing, disabling frame dropping.