I think you should ACK the error response when you get the 4xx/5xx for the first contact. The new INVITE to the second contact should be a new client transaction, although you can re-use the from to and the called , u should use a new branch in the via , See the following excerpt from section 8.1.3.4 of 3261
"Finally, once the new request has been constructed, it is sent using a new client transaction, and therefore MUST have a new branch ID in the top Via field as discussed in Section 8.1.1.7." -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Atul Edlabadkar Sent: Thursday, May 26, 2005 5:10 AM To: Paul Kyzivat; [email protected] Subject: RE: [Sip-implementors] Contact header in 3XX response I am using 3rd party SIP Stack to make new connection for the Contact header from the list. If UAS get 4xx/5xx response for the first Contact then when I try to make connection to the second header from the list and I get error "Transaction already exists" which makes sense because the To, From and Call-id are same. Any comments? Thanks, Atul -----Original Message----- From: Paul Kyzivat [mailto:[EMAIL PROTECTED] Sent: Wednesday, May 25, 2005 4:08 PM To: Atul Edlabadkar Cc: [email protected] Subject: Re: [Sip-implementors] Contact header in 3XX response Atul Edlabadkar wrote: > Hi, > > I would appreciate if someone can comment on following question: > > Does SIP allow multiple Contact headers in 3XX response with same > user-part and destination number but different parameters? I certainly think that is allowed. Do you believe there is some prohibition of it somewhere? In some cases they may not all be tried by a recursing proxy. The rules for a proxy require that it only try a target uri once for a given request. This is to be determined by URI comparison. Depending on the parameter, a uri with a parameter may compare equal to a uri without that parameter. If so, only one of them would be tried. For instance: 302 Contact: <sip:[EMAIL PROTECTED]> Contact: <sip:[EMAIL PROTECTED];baz> Paul _______________________________________________ Sip-implementors mailing list [email protected] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors Confidentiality Notice The information contained in this electronic message and any attachments to this message are intended for the exclusive use of the addressee(s) and may contain confidential or privileged information. If you are not the intended recipient, please notify the sender at Wipro or [EMAIL PROTECTED] immediately and destroy all copies of this message and any attachments. _______________________________________________ Sip-implementors mailing list [email protected] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
