Intent to Prototype: WebRTC RTP header extension control

[Harald Alvestrand]

Contact emails h...@chromium.org,hand...@chromium.org Explainer https://docs.google.com/document/d/1y1hTsMeav5ijPvoqu1R6U4YC564i1QzgkMeIqWhgiis/edit# Design docs/spec Specification: https://github.com/w3c/webrtc-extensions/pull/25 None TAG review None; minor extension Summary Extend the WebRTC RTCRTPTransceiver API to offer control over which RTP header extensions are negotiated. Extend the WebRTC RTCRTPSender API to offer control over which RTP header extensions are sent. Motivation With the number of RTP header extensions being proposed, experimented with or included in implementations, sending them all all the time will incur considerable overhead, and trying to negotiate too many of them has led to interoperability issues. A mechanism for negotiating them is available in SDP, but a control mechanism for this negotiation has not been available. Risks

Interoperability and Compatibility Adding the feature has low interoperability risk; the feature is easily detectable, and will not lead to negotiation failures with browsers that don't support it. The feature has not seen opposition from other browsers, more a sense of "it's not the top of our priority list". If they see the need, it is likely they will implement this. Firefox: No public signals Edge: No public signals Safari: No public signals Web developers: No signals Ergonomics This is a part of the WebRTC PeerConnection API. Activation No particular challenges known. Security The feature makes a few bits of information about the platform (implemented header extensions) available more easily, which aids in fingerprinting to browser release; this information is already available in RTCPeerConnection.createOffer() in a less obvious form, so there is very little new information being exposed.

Will this feature be supported on all six Blink platforms (Windows, Mac, Linux, Chrome OS, Android, and Android WebView)? Yes Is this feature fully tested by web-platform-tests? Yes WPT tests will be added. Link to entry on the Chrome Platform Status https://chromestatus.com/feature/5680189201711104

This intent message was generated by Chrome Platform Status.