There was once a draft that discussed this. (I think maybe Rohan Mahy
was the author.) But it was a long time ago and it no doubt expired.
There seem to be many schools of thought about how to handle early
media, so there have been no agreements on how it should work. Among the
issues are:
- providers that in general won't allow the media to flow until
the session is established
- potential bandwidth issues for forked calls where multiple
forks generate early media
- difficulty in deciding what fork to play if receiving early
media from more than one
But if you only have a single potential early media source, and that
media can flow, then the best recommendation I have seen is to play
early media if you are receiving it. If you are receiving none, and you
have received an 180 then play locally generated ringback. This has
nothing to do with which 1xx responses do/don't contain sdp.
Paul
Vikram Chhibber wrote:
> Normally, remote media is always given more preference than local
> ring-back. But, there are no best practices draft/specifications on
> this as far as I know.
>
> On Thu, Feb 28, 2008 at 10:18 AM, Madhav Bhamidipati <[EMAIL PROTECTED]>
> wrote:
>> I think, 18X with an early media needs to be given preference, 18X
>> with no media is local
>> ringback, but with SDP there might be an identity of the called party.
>>
>> Madhav
>> On 2/28/08, Madhav Bhamidipati <[EMAIL PROTECTED]> wrote:
>>
>>
>>
>>
>> > On 2/27/08, Iñaki Baz Castillo <[EMAIL PROTECTED]> wrote:
>> > > El Wednesday 27 February 2008 07:53:44 A C Sathish-a22713 escribió:
>> > > > All,
>> > > > Can someone give some pointer on what should be UAC behaviour, when
>> > > > it receives 180 Ringing after receiving 183 Response with SDP .
>> > > > Should UAC play local ringing ? Can some one give some draft reference
>> > > > for UAC behaviour of this scenario.
>> > >
>> > > Hi, read this thread about it:
>> > >
>> > >
>> >
>> https://lists.cs.columbia.edu/pipermail/sip-implementors/2008-January/018245.html
>> > >
>> > >
>> > > PD: And don't break mail thread by pressing "Reply" in any other mail to
>> > > generate a new one (your mail appears in the same thread as the mail
>> with
>> > > subject "Query about Supported and require header in Invite".
>> > > Please, to create a NEW mail thread press "Create new" in your mail
>> > client
>> > > instead of press "Reply" in any other message.
>> > >
>> > > Regards.
>> > >
>> > >
>> > > --
>> > > Iñaki Baz Castillo
>> > > [EMAIL PROTECTED]
>> > >
>> > > _______________________________________________
>> > > Sip-implementors mailing list
>> > > [email protected]
>> > > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
>> > >
>> >
>>
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>
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