I don't know of any explicit guidelines but use of "180 Ringing" with SDP is certainly acceptable.
As it says: "This response MAY be used to initiate local ringback." I think this means that you can use SDP if you want your UA to play ringback back to the caller. This has applications in SIP-ISDN gateways (amongst others) where it may wish to pass back a ringback generated by the ISDN side. Attila Attila Sipos Software Engineer Let's talk Business, Let's talk VoIP www.vegastream.com > -----Original Message----- > From: Jasson Casey [mailto:[EMAIL PROTECTED] > Sent: 17 December 2003 15:31 > To: [EMAIL PROTECTED] > Subject: [Sip-implementors] SDP in 180 response > > > I was wondering if there explicit guidelines on whether a SDP > can be passed in 180 responses? The only thing I came up with was: > > 21.1.2 180 Ringing > > The UA receiving the INVITE is trying to alert the user. This > response MAY be used to initiate local ringback. > > 21.1.5 183 Session Progress > > The 183 (Session Progress) response is used to convey information > about the progress of the call that is not otherwise > classified. The > Reason-Phrase, header fields, or message body MAY be used to convey > more details about the call progress. > > There is no reference to body content in the 180 response, > while there is in the 183 response. Some thoughts would be helpful. > > thanks, > > -jasson > > _______________________________________________ > Sip-implementors mailing list > [EMAIL PROTECTED] > http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors > _______________________________________________ Sip-implementors mailing list [EMAIL PROTECTED] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
