Inline regards Rayees
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of johnny kao Sent: Saturday, April 28, 2007 12:30 AM To: [email protected] Subject: [Sip-implementors] Question about termination of a early dialog Hi, 1 . RFC3261 says on page 77: "Independent of the method, if a request outside of a dialog generates a non-2xx final response, any early dialogs created through provisional responses to that request are terminated." Does it only describe the behavior of UAS? Consider the situation below: UAC generates a CANCEL request, it could receive no responses for the initial INVITE request (if UAS followed the RFC2543). Thus, can I suppose that the early dialog of the UAC is terminated while the CANCEL issued? The dialog is not terminated at this point in time. It does point to details of the same in section 15 of RFC. 2. Page 54 says: "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, the client SHOULD then consider the original transaction cancelled and SHOULD destroy the client transaction handling the original request." But the retransmission of the INVITE is stop by the provisional response it received, how the UAC implements this feature? Re-start the timer of the INVITE? Most of the servers do so. RFC 3261 does state the following "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 17.1.1.1), the client SHOULD then consider the original transaction cancelled and SHOULD destroy the client transaction handling the original request." As soon as a CANCEL request is sent a timer is started that lasts 64*T1 to wait for 487 response for INVITE. THX Johnny, TW _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________ ---------------------------------------------------------------------------------- IMPORTANT The information contained in this e-mail any attachments is intended only for the named recipient and may be privileged or confidential. If you are not the intended recipient, please notify us immediately on +44 (0)1908 425000 and do not disclose, copy, distribute or take any action based on the contents of this e-mail. You should understand and accept that, when communicating with us by e-mail, it is not a totally secure communication medium. We accept no liability for any direct, indirect or consequential loss arising from any action taken in reliance on the information contained in this e-mail and give no warranty or representation as to its accuracy or reliability. DIGITALK has the facility to monitor and read both incoming and outgoing communications by e-mail. In line with industry efforts to reduce the proliferation of Un-Solicited SPAM messages, DIGITALK uses various methods including Reverse-DNS lookups and ban-lists to prevent malicious content reaching our users. This message and any attachments has been scanned for known viruses. However, we would advise you to ensure the content is indeed virus free. We do not, to the extent permitted by law, accept any liability (whether in contract, negligence or otherwise) for any virus infection and/or external compromise of security and/or breach of confidentiality in relation to transmissions sent by e-mail. VAT No: GB 876 3287 81. Reg No: 3080801 Place of Registration: England Registered Office Address: 2 Radian Court, Knowlhill, Milton Keynes ----------------------------------------------------------------------------------" _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
