Hi Anil, The Request URI of subsequent requests including ACK MUST be same as the published contact i.e the contact in 200 OK.
Section 13.2.2.4 2xx Responses of RFC 3261 states that The UAC core MUST generate an ACK request for each 2xx received from the transaction layer. The header fields of the ACK are constructed in the same way as for any request sent within a dialog (see Section 12) with the exception of the CSeq and the header fields related to authentication. The sequence number of the CSeq header field MUST be the same as the INVITE being acknowledged, but the CSeq method MUST be ACK. ACK for non-2xx is generated by invite client transaction, hence its Request URI MUST be same as one in initial REQUEST. ( This will be AOR of CALLEE ). With Regards Raghu "Anil Chaudhary" <[EMAIL PROTECTED]> Sent by: [EMAIL PROTECTED] 02/25/2007 10:36 AM To [email protected] cc Subject [Sip-implementors] SIP fundamental question Hi, I have a doubt.. When an INVITE goes UA->CA with req uri (say abc.com) and other side (CA) responds with 200 OK with published contact as xyz.com. Then what should be req uri of ACK ( is it be sip:ab.com / sip:xyz.com ?). Since RFC 3261 says that new request should go to the published Contact. If req uri of ACK is abc.com (which many of examples say) then is it the responsiblity of network element in the dialog path(eg proxies etc) to remember the published contact or it is responsibility of UA to change to req uri to published contact so that routing can be done on req uri. _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors *********************** Aricent-Unclassified *********************** "DISCLAIMER: This message is proprietary to Aricent and is intended solely for the use of the individual to whom it is addressed. It may contain privileged or confidential information and should not be circulated or used for any purpose other than for what it is intended. If you have received this message in error, please notify the originator immediately. If you are not the intended recipient, you are notified that you are strictly prohibited from using, copying, altering, or disclosing the contents of this message. Aricent accepts no responsibility for loss or damage arising from the use of the information transmitted by this email including damage from virus." _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
