If an INVITE request receives no response at all, the UAC does not send anything. It simply considers the transaction a timed out. Timer B will have fired in the Calling state of the INVITE client transaction state machine. The TU is informed and the transaction is destroyed. See section 17.1.1 of RFC 3261.
RFC 3261 requires that a provisional response be received in order to send a CANCEL. Thus a CANCEL can only be sent while in the Proceeding state. You can only send BYE if a dialog has been created by a 1xx or 2xx response with a To-tag. cheers, (-:bob Robert F. Penfield Chief Software Architect Acme Packet, Inc. 130 New Boston Street Woburn, MA 01801 [EMAIL PROTECTED] ----- Original Message ----- From: "Arunachalam Venkatraman" <[EMAIL PROTECTED]> To: "Shankara, Udaya" <[EMAIL PROTECTED]>; "'Bob Penfield'" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Sent: Tuesday, August 27, 2002 12:41 AM Subject: RE: [Sip-implementors] RFC3261 says UAC can send BYE for an early dialog? > Originally, it was CANCEL that was to be sent in this case. Then, back in > bis-03 days, it was decided that if the INVITE was not responded to, the > CANCEL would retransmit 10 times without any response and so, non-receipt of > any response on the INVITE can be treated as having received a 481 and no > further action is necessary. > Subsequently, CANCEL has been conditioned on receipt of a provisional > response and BYE has become a SHOULD. > I think it is good to send a BYE but I am not sure what will break if it is > not sent when no provisional response has been received. > > > > -----Original Message----- > From: Shankara, Udaya [mailto:[EMAIL PROTECTED]] > Sent: Monday, August 26, 2002 11:11 PM > To: 'Bob Penfield'; Arunachalam Venkatraman; > [EMAIL PROTECTED] > Subject: RE: [Sip-implementors] RFC3261 says UAC can send BYE for an > early dialog? > > > Hi, > The caller may send BYE on early or confirmed dialogs as stated below. > Section 12.2.1.2 of RFC 3261 states the following: > > "A UAC SHOULD also terminate a dialog if no response at all is received > for the request." > "For INVITE initiated dialogs, terminating a dialog consists of sending a > BYE." > > Now, if the caller sends INVITE and does not receive any provisional > responses, should it send BYE when the transaction times out? > > Regards, > Udaya > > -----Original Message----- > From: Bob Penfield [mailto:[EMAIL PROTECTED]] > Sent: Friday, July 19, 2002 5:16 AM > To: Arunachalam Venkatraman; [EMAIL PROTECTED] > Subject: Re: [Sip-implementors] RFC3261 says UAC can send BYE for an > early dialog? > > > The statement in section 15 is not an error. You are allowed to send a BYE > instead of CANCEL for an early dialog to terminate only that dialog. This > allows a UAC which receives provisional responses from more than one UAS > (establishing multiple early dialogs), to terminate early dialogs it does > not want if it decides it only wants one of those dialogs to continue. > > A CANCEL would cancel any forked branches and "all" early dialogs that may > have been established as a result of the forking. > > The key is that BYE terminates only the dialog matching the call-id, > from-tag, and to-tag in the BYE. CANCEL terminates the INVITE request and > all forked branches, which would terminate all early dialogs as a side > effect. > > cheers, > (-:bob > > Robert F. Penfield > Chief Software Architect > Acme Packet, Inc. > 130 New Boston Street > Woburn, MA 01801 > [EMAIL PROTECTED] > > ----- Original Message ----- > From: "Arunachalam Venkatraman" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Thursday, July 18, 2002 7:06 PM > Subject: [Sip-implementors] RFC3261 says UAC can send BYE for an early > dialog? > > > > In Section 15 of the RFC3261, it is said - > > ................... > > 15 Terminating a Session > > > > 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. > > .................... > > > > The RFC3261 says elsewhere that a CANCEL must be sent to terminate a > dialog > > inititated by an INVITE. > > > > Is the statement in Section 15 an error? > > As mentioned in the change bullet 31 in Section 28, was it really intended > > to convey that a RFC2543 UAC may do this and the UAS must be prepared for > > it? > > > > _______________________________________________ > > Sip-implementors mailing list > > [EMAIL PROTECTED] > > http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors > > > > _______________________________________________ > Sip-implementors mailing list > [EMAIL PROTECTED] > http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors > > _______________________________________________ > Sip-implementors mailing list > [EMAIL PROTECTED] > http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors > _______________________________________________ Sip-implementors mailing list [EMAIL PROTECTED] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
