diff --git a/api/transport/network_types.h b/api/transport/network_types.h
index a4d46380bc..0693f69c7a 100644
--- a/api/transport/network_types.h
+++ b/api/transport/network_types.h
@@ -85,6 +85,10 @@ struct SentPacket {
   Timestamp send_time = Timestamp::Infinity();
   DataSize size = DataSize::Zero();
   PacedPacketInfo pacing_info;
+  // Transport independent sequence number, any tracked packet should have a
+  // sequence number that is unique over the whole call and increasing by 1 for
+  // each packet.
+  int64_t sequence_number;
 };
 
 // Transport level feedback
diff --git a/api/transport/test/network_control_tester.cc b/api/transport/test/network_control_tester.cc
index a34292ea43..a0bc8d4caa 100644
--- a/api/transport/test/network_control_tester.cc
+++ b/api/transport/test/network_control_tester.cc
@@ -62,6 +62,7 @@ NetworkControllerTester::NetworkControllerTester(
     NetworkControllerFactoryInterface* factory,
     NetworkControllerConfig initial_config)
     : current_time_(Timestamp::seconds(100000)),
+      packet_sequence_number_(1),
       accumulated_delay_(TimeDelta::ms(0)) {
   initial_config.constraints.at_time = current_time_;
   controller_ = factory->Create(initial_config);
@@ -107,8 +108,9 @@ void NetworkControllerTester::RunSimulation(TimeDelta duration,
     }
 
     if (send_packet) {
-      SentPacket sent_packet =
-          next_packet(state_, current_time_, packet_interval);
+      SentPacket sent_packet;
+      sent_packet = next_packet(state_, current_time_, packet_interval);
+      sent_packet.sequence_number = packet_sequence_number_++;
       Update(&state_, controller_->OnSentPacket(sent_packet));
       outstanding_packets_.push_back(SimulateSend(
           sent_packet, packet_interval, propagation_delay, actual_bandwidth));
diff --git a/api/transport/test/network_control_tester.h b/api/transport/test/network_control_tester.h
index 43c6503a69..df52a9bf82 100644
--- a/api/transport/test/network_control_tester.h
+++ b/api/transport/test/network_control_tester.h
@@ -66,6 +66,7 @@ class NetworkControllerTester {
   std::unique_ptr<NetworkControllerInterface> controller_;
   TimeDelta process_interval_ = TimeDelta::PlusInfinity();
   Timestamp current_time_;
+  int64_t packet_sequence_number_;
   TimeDelta accumulated_delay_;
   std::deque<PacketResult> outstanding_packets_;
   NetworkControlUpdate state_;
diff --git a/modules/congestion_controller/rtp/send_side_congestion_controller.cc b/modules/congestion_controller/rtp/send_side_congestion_controller.cc
index 00224bd328..fa010e8234 100644
--- a/modules/congestion_controller/rtp/send_side_congestion_controller.cc
+++ b/modules/congestion_controller/rtp/send_side_congestion_controller.cc
@@ -61,6 +61,7 @@ PacketResult NetworkPacketFeedbackFromRtpPacketFeedback(
     feedback.receive_time = Timestamp::ms(pf.arrival_time_ms);
   if (pf.send_time_ms != webrtc::PacketFeedback::kNoSendTime) {
     feedback.sent_packet = SentPacket();
+    feedback.sent_packet->sequence_number = pf.long_sequence_number;
     feedback.sent_packet->send_time = Timestamp::ms(pf.send_time_ms);
     feedback.sent_packet->size = DataSize::bytes(pf.payload_size);
     feedback.sent_packet->pacing_info = pf.pacing_info;
@@ -542,6 +543,7 @@ void SendSideCongestionController::OnSentPacket(
     SentPacket msg;
     msg.size = DataSize::bytes(packet->payload_size);
     msg.send_time = Timestamp::ms(packet->send_time_ms);
+    msg.sequence_number = packet->long_sequence_number;
     task_queue_->PostTask([this, msg]() {
       RTC_DCHECK_RUN_ON(task_queue_);
       if (controller_)