[moving to sip-implementors] > -----Original Message----- > From: Sharath Rajasekar [mailto:[EMAIL PROTECTED]] > Sent: Wednesday, February 28, 2001 6:51 PM > To: [EMAIL PROTECTED] > Subject: [SIP] Interacting with CAs that dont support CANCEL > > > Hi, > > An interesting call flow resulted when interacting with a > Call Agent that does not support CANCELs. > > Lets say we have two CAs, one (A)supporting CANCEL and the > other (B) that does not support CANCEL and uses BYE instead. > (Support for CANCELs is a "should" not "must" as per bis02) > > Do you treat the CANCEL as a "CANCEL" or as a "BYE" ? > A B > | | > |<-----INVITE-----------| > |-----180-------------->| > |<-----BYE--------------| > |------200------------->| > | | > > Is this legal ? Yes. > > If we treat it as a BYE, as per bis-02, the INVITE must > be completed with a final response and an ACK ? So will > the previous flow, result in another 200OK and an ACK for > that. Yes. > > In the other case, when we send the CANCEL, since the > other CA does not support CANCELs, they drop the CANCELs > and continue to ring the phone after the A has disconnected. Well, I'd also throw that implementation away and buy one that does support CANCEL. > > A B > | | > |------INVITE---------->| > |<-----180--------------| > |------CANCEL---------->| > |<-----180--------------| > |<-----180--------------| > | | > > In this case, should B, send back a 405 Not supported in > response to a CANCEL ? And should we follow that with a > BYE and wait for a 200OK. B should respond with a 405 if it doesn't support CANCEL. Note, however, that BYE is not the same thing as CANCEL. CANCEL terminates a search, ensuring that the phones which answered stay in the call. BYE terminates the call. -Jonathan R. --- Jonathan D. Rosenberg 72 Eagle Rock Ave. Chief Scientist First Floor dynamicsoft East Hanover, NJ 07936 [EMAIL PROTECTED] FAX: (973) 952-5050 http://www.cs.columbia.edu/~jdrosen PHONE: (973) 952-5000 http://www.dynamicsoft.com _______________________________________________ Sip-implementors mailing list [EMAIL PROTECTED] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
