Re: [MMUSIC] [AVTCORE] Duplication semantics drafts

[Magnus Westerlund <[e-mail]>]

On 2011-10-10 20:17, Ali C. Begen (abegen) wrote:
> I revised the two drafts per the feedback in Quebec.
> 
> If there are further comments, we would like to hear about them. As
> of now, there are no open issues from our standpoint except possibly
> defining a new RTCP XR report, which can be done later. Thus, we
> would like these two drafts to be considered and adopted by the
> MMUSIC wg.
> 
> https://datatracker.ietf.org/doc/draft-begen-mmusic-redundancy-grouping/
>
> https://datatracker.ietf.org/doc/draft-begen-mmusic-temporal-interleaving/
> 
> CC'ing AVT(core) since the topic is relevant but please post your
> comments to mmusic where the drafts belong to.
> 

Hi,

(as individual)

I have looked at the redundancy-grouping draft and still think it fails
as RTP specifications for how duplication should be done in RTP, either
using SSRC multiplexing with two different SSRCs in the same RTP session
or for the alternative how having two different RTP sessions. This first
appears to be sufficiently specified, where my only comment is the
dependency on signalling to determine that this grouping is in place. I
do propose that an RTP/RTCP based complement is derived. I would
personally suggest that my own proposal for a new SDES item SRCNAME is
used but that should clearly be discussed.

For the case where multiple RTP sessions are used, it is still not clear
how a receiver determine which SSRC in each RTP session that are
related. And I would like to point out that CNAME is not sufficient.

I still think we should consider splitting this into one AVTCORE
document discussing the RTP aspects of duplication, and another MMUSIC
document defining the grouping semantics.

Cheers

Magnus Westerlund

----------------------------------------------------------------------
Multimedia Technologies, Ericsson Research EAB/TVM
----------------------------------------------------------------------
Ericsson AB                | Phone  [phone]
Färögatan 6                | Mobile [phone]
SE-164 80 Stockholm, Sweden| mailto: [e-mail]
----------------------------------------------------------------------