18 mar 2010 kl. 12.34 skrev Iñaki Baz Castillo: > 2010/3/18 Rodriguez Merchan, Pedro Julian <pjrmerc...@indra.es>: >> What must i do when i receive the SESSION PROGRESS instead the RINGING? > > Nothing special, the UAC should b able to receive such RTP (real > audio) and render it to the human via the phone speaker. > It's really common and 200% valid.
As a best current practise, I would recommend first sending a 180 Ringing, so that all involved applications can change state. The 183 could very well mean an error message, so you can not assume that it means ringing. Not sending 180 makes life very hard for gateways. You are also allowed to include sdp in an 180 message and both send your preferred ring tone and change state in the same message. /O _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
