Re: [MMUSIC] RTP/AVP vs RTP/AVPF vs RTP/SAVPF vs .... how to pick a default?

[Emil Ivov <[e-mail]>]

Oops, hit sent a bit too early. I wanted to add that that the least
painful option would obviously be to add tcap attributes as per 5939
and then keep RTP/AVP in the m= line but that would still be rejected
by a WebRTC endpoint (right?) so do we need to adjust JSEP to allow
RTP/AVP if the m= line contains the necessary transport capabilities?

Emil


On Wed, Oct 9, 2013 at 5:44 PM, Emil Ivov <[e-mail]> wrote:
> Hey all,
>
> We've recently implemented support for DTLS/SRTP and a question that
> we had somehow avoided in the past with SDES and ZRTP is now back on
> the table:
>
> By default, which profile would a SIP UA use in an outgoing offer?
>
> Until recently recently we were offering RTP/AVP by default, which is
> ok for ZRTP and tolerated by most of the endpoints that support SDES.
>
> We also had a couple of config options that allowed Jitsi to (A)
> create offers with RTP/SAVP(F) in case someone turned out to be picky
> about the transport or (B) duplicate all m= lines and offer them with
> every supported transport so that the remote endpoint would pick what
> it likes.
>
> Obviously option (A) is not a suitable default for a generic SIP UA
> because that would make it incompatible with the majority of the
> endpoints that exist today. (B) could have worked but now that we are
> going for "Unified", having the same "m=" line appear with RTP/AVP and
> then again with RTP/SAVPF would have to be interpreted as two
> independent streams rather than the same stream being available over
> two different transports.
>
> So, do we have a story here or do we need to create one?
>
> Emil
>
> --
> https://jitsi.org



-- 
Emil Ivov, Ph.D.                       67000 Strasbourg,
Project Lead                           France
Jitsi
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