Subject: Re: [Perc] MID and RID

From: Jonathan Lennox <[email-masked]>
Date: Tue, 1 Dec 2015 22:54:50 +0000

> On Nov 30, 2015, at 6:42 PM, Cullen Jennings <[email-masked]> wrote:
> 
> 
>> On Nov 30, 2015, at 12:49 PM, Jonathan Lennox <[email-masked]> wrote:
>> 
>> This is also the issue I raised in today’s call about SSRC rewriting.  Currently, we have no way to give a stream more than one MID at a time, so if you have role-based MIDs there’s no way for a given SSRC to have more than one role at a time.  In non-PERC scenarios, the solution to this is stream duplication, but if we don’t allow SSRC rewriting that won’t be possible.
> 
> But sending two more or less identical copies of the same video to the same endpoint is just such a bandwidth wasted that it seems we really need a better solution than that. Like being able to assign multiple labels designed  to identify the role(s) to the stream. It's rather see us solve that problem that way. 

I agree that streams with multiple roles would be better, but if you assume that roles correspond to m-lines, that’s a pretty high impedance mismatch with the direction we’ve decided to go for BUNDLE.

---

From: Magnus Westerlund <[email-masked]>
Date: Wed, 2 Dec 2015 15:42:38 +0100

Den 2015-11-30 kl. 19:12, skrev Mo Zanaty (mzanaty):
> It's unfortunate we never reached some important header extensions like
> MID and RID in today's design meeting. The proposed MDD behavior (can't
> modify) in the slides does not seem right. Like PT, these values are
> dictated by signaling negotiation, and it may be impossible for MDDs to
> force symmetry and uniformity in the signaling negotiation across all
> participants in order to avoid modifying these values. So I think the
> MDD should be allowed to modify these, and we may want to preserve
> original values for the same reason as PT (in case highly secure
> implementations go as far as ensuring MDD signaling is reasonable given
> some E2E signaling).
>

Yes, I hadn't considered MID and RID and the CLUE capture ID properly 
when doing that slide for the SDES items. It needs to categorize the 
individual SDES items. It appears clear that we have both end-to-end 
ones like CNAME, as well as hop-by-hop ones such as MID.

Cheers

Magnus Westerlund

----------------------------------------------------------------------
Services, Media and Network features, Ericsson Research EAB/TXM
----------------------------------------------------------------------
Ericsson AB                 | Phone  +46 10 7148287
Färögatan 6                 | Mobile +46 73 0949079
SE-164 80 Stockholm, Sweden | mailto: [email-masked]
----------------------------------------------------------------------