Re: [Linphone-developers] Mediastreamer newbie seeks clue.

[Herb Peyerl]

On Thu, Sep 02, 2010 at 08:15:43AM -0400, Herb Peyerl wrote:
> So according to the source, if multiple SSRC's are received within
> a single RtpSession, then oRTP changes the SSRC assigned to the
> session... But it is my understanding that an RTP session can have
> multiple SSRC's... ie: if multiple senders are sending to a single
> localport in a multicast group...

I apologize for replying to my own message and belaboring the point.

It appears this has been brought up before:

http://lists.nongnu.org/archive/html/linphone-developers/2009-06/msg00015.html

Simon Morlat states this is not supported by RTP. 

If I read RFC3550 correctly, this is actually directly supported
and referred to as a "multi-party RTP session" 

- p.9 in the definition of "RTP session".

- Again on p.16 more explicitely:

   On the other hand, multiplexing multiple related sources of the same
   medium in one RTP session using different SSRC values is the norm for
   multicast sessions.  The problems listed above don't apply: an RTP
   mixer can combine multiple audio sources, for example, and the same
   treatment is applicable for all of them.  It may also be appropriate
   to multiplex streams of the same medium using different SSRC values
   in other scenarios where the last two problems do not apply.


My question is, if it is agreed that the RFC takes precedence over
the oRTP implementation, what is the correct way to fix this? I imagine
fixing this will require more sweeping changes in linphone and elsewhere...

...or should I just drop this ?