Re: FW: [rtcweb] How to signal RTX SSRCs with simulcast

To follow up on this, I suggest making the following addition to draft-ietf-mmusic-rid:

---- AFTER this text in section 4 ----

   An "a=rid" SDP media attribute specifies restrictions defining a
   unique RTP payload configuration identified via the "rid-id" field.
   This value binds the restriction to the RTP Stream identified by its
   RTP Stream Identifier SDES item [I-D.ietf-avtext-rid].  To be clear,
   implementations that use the "a=rid" parameter in SDP MUST support
   the RtpStreamId SDES item described in [I-D.ietf-avtext-rid].  Such
   implementations MUST send it for all streams in an SDP media
   description ("m=") that have "a=rid" lines remaining after applying
   the rules in Section 6 and its subsections.

---- ... add this proposed, new text ----

   Implementations that use the "a=rid" parameter in SDP and that
   make use of redundancy RTP streams [RFC7656], e.g. RTP RTX
   [RFC4588] or FEC [RFC5109][I-D.ietf-payload-flexible-fec-scheme],
   for any of the source RTP streams that have "a=rid" lines remaining
   after applying the rules in Section 6 and its subsections, MUST
   support and use RepairedRtpStreamId SDES item described in
   [I-D.ietf-avtext-rid] for those redundancy RTP streams. This provides
   the binding between the source RTP stream and the corresponding
   redundancy RTP stream, by setting RepairedRtpStreamId value for
   the redundancy RTP stream to the RtpStreamId value of the source
   RTP stream. The redundancy RTP stream MAY (but need not) have an
   "a=rid" line of its own, in which case the RtpStreamId SDES item value
   will be different from the corresponding source RTP stream.

---- End changes ----

The -simulcast draft would be entirely agnostic to this clarification of "a=rid" and RepairedRtpStreamId usage and thereby transparently allow using redundancy RTP streams with simulcast.

/Bo
(as individual)

> -----Original Message-----
> From: Iñaki Baz Castillo [mailto:[email protected]]
> Sent: den 13 mars 2017 14:43
> To: Bo Burman <[email protected]>
> Cc: mmusic ([email protected]) <[email protected]>; Taylor Brandstetter ([email protected])
> <[email protected]>; [email protected]; [email protected]
> Subject: Re: [MMUSIC] FW: [rtcweb] How to signal RTX SSRCs with simulcast
> 
> 2017-03-13 14:41 GMT+01:00 Bo Burman <[email protected]>:
> > [BoB] Usage of RepairedRtpStreamId and RtpStreamId are already defined on RTP level by -avtext-rid. If we have
> preferences on how to best use them with redundancy RTP streams in general, I suggest we add text to -mmusic-rid
> about it. This would be regardless if we go for option A or B, but decided once and for all, thus applicable to RFC 4588 rtx
> and FLEX-FEC alike.
> 
> Agreed.
> 
> 
> --
> Iñaki Baz Castillo
> <[email protected]>
_______________________________________________
mmusic mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/mmusic