Re: [rtcweb] [MMUSIC] Is bundle just a port override?

On 03/19/2013 05:19 AM, Mo Zanaty (mzanaty) wrote:
>
> Does bundle imply anything beyond a simple port override of the m-line 
> port? If not, then why not just directly signal the port override in 
> an attribute without any grouping semantics?
>

No, it's not just a port override.

BUNDLE shoves things into the same RTP session, which means that one has 
to obey the rules for being in the same RTP session:
- Security done consistently
- RTCP-mux done consistently
- No SSRC collision
- No payload type collision
So it's a good deal more than just a port override.

Magnus argued in favour of a solution that inserted a multiplex layer, 
so that one could use the same ports but still have stuff in different 
RTP sessions, but that did not appeal to many.

> Offer to mux audio and video on the same port:
>
> m=audio 10000 RTP/AVP 0
>
> m=video 10002 RTP/AVP 31
>
> a=port 10000
>
> i=I really want 10000, but lied on the m-line for fear of confusing 
> you. Confused yet?
>
> Answer supports the port override attribute and agrees to mux audio 
> and video:
>
> m=audio 40000 RTP/AVP 0
>
> m=video 40000 RTP/AVP 31
>
> a=port 40000
>
> ...so audio and video ports are 10000<->40000.
>
> Answer supports the port override attribute but doesn't want to demux 
> on his end:
>
> m=audio 40000 RTP/AVP 0
>
> m=video 40002 RTP/AVP 31
>
> a=port 40002
>
> ...so audio ports are 10000<->40000 and video ports are 10000<->40002.
>
> Answer doesn't support the port override attribute, or doesn't want 
> either end to mux:
>
> m=audio 40000 RTP/AVP 0
>
> m=video 40002 RTP/AVP 31
>
> ...so audio ports are 10000<->40000 and video ports are 10002<->40002.
>
> Either end can re-offer without lies about ports on the m-line after 
> confirming the peer is not confused by muxing, if they want to avoid 
> confusing intermediaries.
>
> Has this approach been tried yet? Dismissed?
>
> Mo
>
>
>
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