Hi Santosh, I think what you mean by establishing a dialog is changing of dialog state to "confirm" from early. Any 101-199 and 2xx response with a "To" tag will establish an early dialog. A UAC (but not UAS) can terminate the early dialog by sending a Bye. RFC 3261 section 15: "A UA MUST NOT send a BYE outside of a dialog. The caller's UA MAY send a BYE for either confirmed or early dialogs, and the callee's UA MAY send a BYE on confirmed dialogs, but MUST NOT send a BYE on early dialogs." Regards, Rahul
-----Original Message----- From: Santosh Reddy [mailto:[EMAIL PROTECTED] Sent: Wednesday, July 05, 2006 7:31 PM To: [EMAIL PROTECTED]; [email protected] Subject: RE: [Sip-implementors] Query on 4xx response to PRACK Hi Rahul, How can a UAC send BYE without establishing transaction/dialog? -Santosh -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Rahul Sent: Tuesday, July 04, 2006 1:18 PM To: [email protected] Subject: Re: [Sip-implementors] Query on 4xx response to PRACK The 183 response sent establishes an early dialog. Any request which generates 4xx response should terminate the dialog i.e the UAC sends a BYE to terminate the dialog. Rahul Hi, I have one doubt. Take a scenario where A calls B. B sends 100 Trying and 183 Session Progress to ingress side. The ingress side sends PRACK in response to 183. Now B sends 4xx in response to PRACK. Now what happens to the PRACK and what response sent to the INVITE request from A. Please find the call flow if you need. Regards, Santosh _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors ___________________________________________________________ All new Yahoo! Mail "The new Interface is stunning in its simplicity and ease of use." - PC Magazine http://uk.docs.yahoo.com/nowyoucan.html _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
