From: Laura Meng Sent: Wednesday, January 19, 2005 1:59 PM > double ringback, it seem one from 180, another from 183, but why this two > response occure togather? is it because the proxy fork INVITE to a PSTN > phone as well as IP phone?
Yes, this is due to forking. > if so, should the proxy forward all the 180/183 back? Yes. > if so, what a mass at the UA's end, it start a single phone to want > to talk to someone, but turn out maybe it could get a meeting there! In case of the first final response arriving at the forking proxy this proxy must cancel all other pending transactions. So in normal forking case the UAC will get more 18x responses but only one 200 (RFC 3261 16.7-10). I hope that helps Franz _______________________________________________ Sip-implementors mailing list [email protected] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
