Re: [rtcweb] Plan A, respun

[Adam Roach <[e-mail]>]

On 5/7/13 14:29, Paul Kyzivat wrote:
> If I bundle an m-line without a=ssrc, and with unique PTs, do you 
> consider it ok if there are multiple "anonymous" flows each complying 
> to the attributes of the m-line?

I presume, by "multiple anonymous flows," you mean multiple series of 
packets with the same PT, but with different SSRC values.

> Or do you assume that all packets with that PT are treated as one 
> flow, switching from one SSRC to another as they are received?

In the example you gave, all of those packets are defined to be 
associated with the same media line. Looking at basic principles, the 
intention here is that the semantics would be identical to non-webrtc, 
non-bundle clients receiving multiple SSRCs on the same port. 
Admittedly, those semantics have never been crystal clear, but my 
experience is that most systems would use this approach to send multiple 
streams that are semantically the same "thing" and should be rendered as 
one "thing" (e.g., window, speaker, etc).

Specifically, we are *not* trying to allow the situation in which (1) 
the SDP has no SSRC for the m-lines in a bundle group; (2) the party who 
generated the SDP receives multiple streams (distinguished, presumably, 
by SSRC) with the same PT, and (3) the recipient then deduces that there 
should be two different rendering outputs (e.g., windows) as a result. 
That is specifically and intentionally one of the behaviors we removed 
from the Orlando proposal, since it severely dilutes the value of 
preserving existing SDP semantics.

Does that answer the question you're answering?

/a