Re: [MMUSIC] BUNDLE and DATA CHANNEL - Paul's example

[Martin Thomson <[e-mail]>]

On 29 April 2013 10:05, Paul Kyzivat <[e-mail]> wrote:
> On 4/29/13 10:41 AM, Christer Holmberg wrote:
>> In your example there is only one SCTP m- line, and in WebRTC I guess it
>> will also be the case, but SDP doesn't prevent you from using multiple SCTP
>> m- lines - unless BUNDLE explicitly forbids it, that is.
>
> I agree. If we want to support that, then the obvious way (for DTLS/SCTP) is
> via SCTP port. That depends on there being a way to specify the SCTP with
> DTLS/SCTP. That has come and gone from the SDP proposal for SCTP.

I don't care whether SDP supports it or not, I care whether it makes
sense to do it at all.

There's a reason why you might not want to mux SCTP - it's a protocol
with multiplexing support.  Multiplexing outside of it is at best a
crude thing to do and at worst a way to dilute congestion signals.

I can understand how you can conceive of scenarios where different
application layer protocols don't play well together enough that you
want more aggressive separation.  I don't see significant value in
supporting those scenarios.

That doesn't completely preclude the future use of SCTP port for
demux, but it does constrain complexity.