Rodrigo Pimenta Carvalho <pime...@inatel.br> writes: > For example, when user U1 calls and his call is forked (parallel > fork) to users U2 e U3, if there is early media negotiation between > the caller and the callees, can U1 keep the media stream with U2 and > U3 simultaneously?
It is possible, the establishment of media between the caller and each callee is independent. The difficulties are how to recognize the situation and how the caller can handle it. The caller will usually see the two media streams coming from different IP addresses/ports. Usually, the source addresses of the streams correspond to the addresses given in the SDP the callees send, but not always. And the media may start arriving at the caller before the SDP arrives. In a perfect world, the caller would test each media stream for whether it is "silent", and then all of those that are not silent would be mixed for presentation to the user. (Humans can usually parse multiple audio sources.) If an early dialog receives a 18x response but there is no media stream that can be matched with that callee, it may be valuable for the calling UA to include an appropriate audio signal in the mix -- a ringing tone for a 180, a forwarding tone for a 181, etc. Dale _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
