----- Original Message ----- From: "A Venkatraman" <[EMAIL PROTECTED]> To: "Robert Sparks" <[EMAIL PROTECTED]>; "'Paul Kyzivat'" <[EMAIL PROTECTED]> Cc: "'Bob Penfield'" <[EMAIL PROTECTED]>; "Wei BJ Lu" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Sent: Friday, November 16, 2001 11:58 AM Subject: RE: [Sip-implementors] How does forking proxy handle To Tag in errorresponse selection?
> Robert > It is understood that the receipt of a non-2xx final response on one of the > provisional call-legs should cleanup the state in all other call-legs for > that transaction and a timer started for the call-leg that received the > non-2xx final response. > If a 2xx class response is received on one call-leg, a timer should be > started on the other legs for cleaning up if no 2xx class is ever received > on the others. If the UAC wanted to make sure the incomplete dialogs were ended, it is allowed to send BYE. The UAC would only get another 2xx if the proxy did not cancel the other branches, or the proxy's CANCEL and the 2xx from the UAS "passed on the wire". > I am not sure that we should impose an additional twist on the UAC by > allowing the proxy to create a new call-leg by sending the non-2xx response > with a tag that is different from the ones on the provisionals that have > been forwarded, earlier. > > When picking a best reponse, can we not suggest that the proxy re-use a tag > from one of the final responses it is choosing from? Bis-05 lines 2370-2371 currently says "The tag in the To header..... If the forwarded response did not have one, it MUST NOT be inserted by the proxy". So a proxy cannot insert a tag of its own. Only UASes can insert tags in the To header. So if the proxy is simply selecting the "best" response for *forward*, it leaves the tag alone. If it is contructing a response as a UAS, I suppose it could insert its own tag. _______________________________________________ Sip-implementors mailing list [EMAIL PROTECTED] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
