[asterisk-users] 180 Ringing with SDP

[Douglas Garstang]

> -----Original Message-----
> From: asterisk-users-bounces at lists.digium.com [mailto:asterisk-users-
> bounces at lists.digium.com] On Behalf Of Alex Balashov
> Sent: Monday, June 18, 2007 5:27 PM
> To: Asterisk Users Mailing List - Non-Commercial Discussion
> Subject: Re: [asterisk-users] 180 Ringing with SDP
> 
> On Mon, 18 Jun 2007, Jared Smith wrote:
> 
> > I could be totally off base here, but it's my understanding that a
180
> > is telling Asterisk to generate ringing on it's side, and that a 183
> > (with SDP) would tell Asterisk that the call is progressing and that
it
> > should play the early media specified in the SDP.  I'm sure someone
> > there's probably someone on the list who is more intimate with the
> > details of SIP that can enlighten us further on the subtle
differences
> > between the 180 and 183 provisional responses.
> 
>    A cursory interpretation of the RFC suggests that 180 Ringing is a
> message designed solely to convey ringback, and that it is the payload
> of the 183 response that may be used to convey additional details
> about the nature of the call's progress.  Therefore, a 180 would be an
> inappropriate vehicle for early media SDP information.

Tell that to level 3. :)