Is RTCP XR (RFC 3611) used in WebRTC or Janus

[Sam]

I am not able to find any information on this topic.  I am looking at Janus and in Janus rtcp.c, I see that five RTCP types are terminated, including the standard SR, RR, then RTP_FB and PS_FB & finally XR.

Where is the use case for RTCP XR in webRTC?  Can someone point to some RFC or some implementation that uses this RTCP type?

[Lorenzo Miniero]

No, we don't support XR yet. The code you see is a placeholder just so that we don't print an error if the parser goes through an XR packet.

As to how they can be used in WebRTC, there's a brief mention here: https://tools.ietf.org/html/draft-ietf-rtcweb-rtp-usage-26

Lorenzo

[samuel]

Thanks for the info.

I have tried to understand the different RTCP message types and issues in relaying or terminating/transforming them for a SFU. I  have gone through your RFC 8079. 

Will it be too much to ask what is Janus' overall approach? I saw one of your earlier posts which talked about you simply relaying all the RTCP messages.

Currently what RTCP message types are relayed by Janus? Which are transformed? I am going through the code but a quick comment will help a lot.

I think that RTCP message management is 90% of the complexity of a system like Janus. Would you agree? 

[Lorenzo Miniero]

We terminate SR, RR and NACK, and generate our own. Everything else (mostly PLI and REMB) goes through, and we just "fix" the SSRCs along the way.

Lorenzo