Hello Madhuri , I think the callee should send back a 481 (transaction does not exist) to the caller in response to the cancel request as the final response to the INVITE transaction has already been sent. Then finally when the 200 OK gets out of the stack on completion of the PRACK transaction , the caller can ACK the 200 OK and then immedietly send a BYE. Regards , Sayan
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Madhuri Sakhare Sent: Thursday, May 25, 2006 7:40 PM To: [email protected] Subject: [Sip-implementors] Query Regarding Collision case of CANCEL. Hi, Consider this call flow: UAC UAS | INVITE | |----------------------->| | 180 RINGING | |<-----------------------| | CANCEL | |----------------------->| | 200 OK CANCEL | |<-----------------------| | | This is a collision case of a reliable 180 response and a CANCEL Request. The application on the callee side has sent a 200 OK response, and the response is left pending in the SIP stack. Then the collision occurs and the CANCEL is indicated to the application, but since it has already sent a final response, it has no way of sending another one. The call is not freed. How should the SIP stack responds to this? Regards, Madhuri _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors 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 proprietary, confidential or privileged information. If you are not the intended recipient, you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately and destroy all copies of this message and any attachments. WARNING: Computer viruses can be transmitted via email. The recipient should check this email and any attachments for the presence of viruses. The company accepts no liability for any damage caused by any virus transmitted by this email. www.wipro.com _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
