Sachin, (sorry for the previous response sent by a mistake.)
Per the following text in Section 9.1, the INVITE client transaction should be terminated after 64*T1 seconds after sending the CANCEL. I think the proxy would send a 408 to the UAC in this case although I couldn't find any specific reference to this. "Note that both the transaction corresponding to the original request and the CANCEL transaction will complete independently. However, a UAC canceling a request cannot rely on receiving a 487 (Request Terminated) response for the original request, as an RFC 2543-compliant UAS will not generate such a response. If there is no final response for the original request in 64*T1 seconds (T1 is defined in Section 17.1.1), the client SHOULD then consider the original transaction cancelled and SHOULD destroy the client transaction handling the original request." YoungSun > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Sachin > Sent: Thursday, May 04, 2006 5:58 AM > To: [email protected] > Subject: [Sip-implementors] Proxy Timer C processing - how > does it help? > > Hello, > > According to RFC if Timer C fires at proxy, it should > generate CANCEL (provided 1xx was received). Now if the > CANCEL gets 200 OK but the original INVITE does not receive > any final response, what should the proxy do? Won't the > INVITE client transaction continue to hang forever? Won't > this beat the purpose of Timer C, which is there... > > "In order to handle the case where an INVITE request *never* > generates a final response,..." > > > INV INV > UAC ------------> P1 --------------> UAS > 100 100 > <------------ <-------------- > > [Timer C Fires] > CANCEL > ---------------> > 200(CANCEL) > <--------------- > > [No final for INVITE yet.] > > > Thanks, > Sachin > > 16.8 Processing Timer C > > " If timer C should fire, the proxy MUST either reset the timer with > any value it chooses, or terminate the client transaction. If the > client transaction has received a provisional response, the proxy > MUST generate a CANCEL request matching that transaction. If the > client transaction has not received a provisional > response, the proxy > MUST behave as if the transaction received a 408 (Request Timeout) > response." > > _______________________________________________ > Sip-implementors mailing list > [email protected] > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
