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Adds RTT based backoff trial to SendSideBandwidthEstimation.

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Bug: webrtc:9718
Change-Id: Ic94dcd7612524d350f54d1907f843577b890badf
Reviewed-on: https://webrtc-review.googlesource.com/c/104122
Commit-Queue: Sebastian Jansson <srte@webrtc.org>
Reviewed-by: Christoffer Rodbro <crodbro@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25048}
This commit is contained in:
Sebastian Jansson
2018-10-08 12:49:53 +02:00
committed by Commit Bot
parent d2fb1bfeba
commit 2e068e8b6f
5 changed files with 91 additions and 19 deletions
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50
modules/congestion_controller/goog_cc/goog_cc_network_control.cc
View File

@ -250,6 +250,13 @@ NetworkControlUpdate GoogCcNetworkController::OnSentPacket(
SentPacket sent_packet) {
alr_detector_->OnBytesSent(sent_packet.size.bytes(),
sent_packet.send_time.ms());
if (!first_packet_sent_) {
first_packet_sent_ = true;
// Initialize feedback time to send time to allow estimation of RTT until
// first feedback is received.
bandwidth_estimation_->UpdatePropagationRtt(sent_packet.send_time,
TimeDelta::Zero());
}
return NetworkControlUpdate();
}
@ -331,24 +338,30 @@ NetworkControlUpdate GoogCcNetworkController::OnTransportLossReport(
NetworkControlUpdate GoogCcNetworkController::OnTransportPacketsFeedback(
TransportPacketsFeedback report) {
TimeDelta feedback_max_rtt = TimeDelta::MinusInfinity();
TimeDelta max_feedback_rtt = TimeDelta::MinusInfinity();
TimeDelta min_propagation_rtt = TimeDelta::PlusInfinity();
Timestamp max_recv_time = Timestamp::MinusInfinity();
for (const auto& packet_feedback : report.ReceivedWithSendInfo()) {
TimeDelta rtt =
report.feedback_time - packet_feedback.sent_packet->send_time;
// max() is used to account for feedback being delayed by the
// receiver.
feedback_max_rtt = std::max(feedback_max_rtt, rtt);
max_recv_time = std::max(max_recv_time, packet_feedback.receive_time);
std::vector<PacketResult> feedbacks = report.ReceivedWithSendInfo();
for (const auto& feedback : feedbacks)
max_recv_time = std::max(max_recv_time, feedback.receive_time);
for (const auto& feedback : feedbacks) {
TimeDelta feedback_rtt =
report.feedback_time - feedback.sent_packet->send_time;
TimeDelta min_pending_time = feedback.receive_time - max_recv_time;
TimeDelta propagation_rtt = feedback_rtt - min_pending_time;
max_feedback_rtt = std::max(max_feedback_rtt, feedback_rtt);
min_propagation_rtt = std::min(min_propagation_rtt, propagation_rtt);
}
absl::optional<int64_t> min_feedback_max_rtt_ms;
if (feedback_max_rtt.IsFinite()) {
feedback_max_rtts_.push_back(feedback_max_rtt.ms());
if (max_feedback_rtt.IsFinite()) {
feedback_max_rtts_.push_back(max_feedback_rtt.ms());
const size_t kMaxFeedbackRttWindow = 32;
if (feedback_max_rtts_.size() > kMaxFeedbackRttWindow)
feedback_max_rtts_.pop_front();
min_feedback_max_rtt_ms.emplace(*std::min_element(
feedback_max_rtts_.begin(), feedback_max_rtts_.end()));
bandwidth_estimation_->UpdatePropagationRtt(report.feedback_time,
min_propagation_rtt);
}
if (packet_feedback_only_) {
if (!feedback_max_rtts_.empty()) {
@ -359,7 +372,7 @@ NetworkControlUpdate GoogCcNetworkController::OnTransportPacketsFeedback(
}
TimeDelta feedback_min_rtt = TimeDelta::PlusInfinity();
for (const auto& packet_feedback : report.ReceivedWithSendInfo()) {
for (const auto& packet_feedback : feedbacks) {
TimeDelta pending_time = packet_feedback.receive_time - max_recv_time;
TimeDelta rtt = report.feedback_time -
packet_feedback.sent_packet->send_time - pending_time;
@ -428,10 +441,13 @@ NetworkControlUpdate GoogCcNetworkController::OnTransportPacketsFeedback(
// No valid RTT could be because send-side BWE isn't used, in which case
// we don't try to limit the outstanding packets.
if (in_cwnd_experiment_ && min_feedback_max_rtt_ms) {
if (in_cwnd_experiment_ && max_feedback_rtt.IsFinite()) {
int64_t min_feedback_max_rtt_ms =
*std::min_element(feedback_max_rtts_.begin(), feedback_max_rtts_.end());
const DataSize kMinCwnd = DataSize::bytes(2 * 1500);
TimeDelta time_window =
TimeDelta::ms(*min_feedback_max_rtt_ms + accepted_queue_ms_);
TimeDelta::ms(min_feedback_max_rtt_ms + accepted_queue_ms_);
DataSize data_window = last_bandwidth_ * time_window;
if (current_data_window_) {
data_window =
@ -440,7 +456,7 @@ NetworkControlUpdate GoogCcNetworkController::OnTransportPacketsFeedback(
data_window = std::max(kMinCwnd, data_window);
}
current_data_window_ = data_window;
RTC_LOG(LS_INFO) << "Feedback rtt: " << *min_feedback_max_rtt_ms
RTC_LOG(LS_INFO) << "Feedback rtt: " << min_feedback_max_rtt_ms
<< " Bitrate: " << last_bandwidth_.bps();
}
update.congestion_window = current_data_window_;

2
modules/congestion_controller/goog_cc/goog_cc_network_control.h
View File

@ -73,6 +73,8 @@ class GoogCcNetworkController : public NetworkControllerInterface {
absl::optional<NetworkControllerConfig> initial_config_;
bool first_packet_sent_ = false;
Timestamp next_loss_update_ = Timestamp::MinusInfinity();
int lost_packets_since_last_loss_update_ = 0;
int expected_packets_since_last_loss_update_ = 0;