The parts of the RTC Media API (https://w3c.github.io/webrtc-pc/#rtp-media-api) that allow keeping track of contributing sources for receiving tracks. RTCPeerConnection extension: getReceivers(). RTCRtpSender support: track, getContributingSources(). RTCRtpContributingSource support: timestamp, source. Feature for the rest of the API: https://www.chromestatus.com/feature/5347809238712320
Docs: https://developer.mozilla.org/en-US/docs/Web/API/WebRTC_API