Tadkot, I think the problem is here --> ".... and insert it own VIA header field value."
Section 9.1 of RFC 3261 states that - "A CANCEL constructed by a client MUST have only a single Via header field value matching the top Via value in the request being cancelled." I am not sure about the branch parameter though (but my guess is that should be the same too). Regards, Anshuman S. Rawat Software Group, Conexant Systems India Private Ltd. -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Friday, November 18, 2005 5:26 PM To: Sip-Implementors Subject: [Sip-implementors] CANCEL message construction at proxy level Hi All, I am new to this mail grpu and SIP world :). I need some information about how to construct the CANCEL message at the proxy level. Scenario 1> Caller A sends INVITE message to PROXY 2> PROXY(stateful) send 100 trying to caller A and sends the INVITE message to caller B 3> Caller A sends CANCEL message to PROXY to cancel the INVITE message 4> PROXY send 200 OK and 487 response back to Caller A and checks for 1xx response from caller B and construct the CANCEL message to send to caller B 5> PROXY construct this message with same Request-URI, TO , FROM, CALL-ID and Cseq number field values of the INVITE message send to caller B and insert it own VIA header field value. the branch id is different from the one which is sent in INVITE message to caller B. 5> But the CALLER B sends 481 Call/Transaction Does Not Exist message back to PROXY. NOTE: if the CALLER B is CISCO media gateway, then it accept CANCEL message by sending 200 OK and 487 message, But if it is a Pingtel phone then it sends 481. Any clue why the behavior is different here. Thanks and Regards -venkat _______________________________________________ Sip-implementors mailing list [email protected] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors ********************** Legal Disclaimer **************************** "This email may contain confidential and privileged material for the sole use of the intended recipient. Any unauthorized review, use or distribution by others is strictly prohibited. If you have received the message in error, please advise the sender by reply email and delete the message. Thank you." ********************************************************************** _______________________________________________ Sip-implementors mailing list [email protected] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
