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

[Adam Roach <[e-mail]>]

Thanks! These changes look good to me, and I've added them to a -11 
version of the document, and uploaded it to the i-d repository:

https://www.ietf.org/id/draft-ietf-mmusic-rid-11.txt

/a

On 7/6/17 13:49, Bo Burman wrote:
> 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:[e-mail]]
>> Sent: den 13 mars 2017 14:43
>> To: Bo Burman <[e-mail]>
>> Cc: mmusic ([e-mail]) <[e-mail]>; Taylor Brandstetter ([e-mail])
>> <[e-mail]>; [e-mail]; [e-mail]
>> Subject: Re: [MMUSIC] FW: [rtcweb] How to signal RTX SSRCs with simulcast
>>
>> 2017-03-13 14:41 GMT+01:00 Bo Burman <[e-mail]>:
>>> [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
>> <[e-mail]>