Header extension official list review

[robin-raymond]

I think we should review this list:
http://ortc.org/wp-content/uploads/2016/03/ortc.html#headerextensions*

And collect any others that are being used here because I know in practice we probably need to implement more than officially required.

[robin-raymond]

See https://tools.ietf.org/html/draft-ietf-rtcweb-rtp-usage-25#page-18

I noticed video orientation is missing. Other ext are useful too even if not officially required yet.

5.2.5.  Coordination of Video Orientation

   WebRTC endpoints that send or receive video MUST implement the
   coordination of video orientation (CVO) RTP header extension as
   described in Section 4 of [I-D.ietf-rtcweb-video].

   This header extension uses the [RFC5285] generic header extension
   framework, and so needs to be negotiated before it can be used.

[robin-raymond]

https://webrtc.org/experiments/rtp-hdrext/abs-send-time/

[robin-raymond]

Needed? https://tools.ietf.org/html/rfc5450

[aboba]

Should we add Abs-Send-Time to the header extension list (as a non-normative reference)? It is widely implemented.