Hi Iñaki,
I know now I was confising about some terms used by RFC. In fact, section 15 says clearly in first phrase: "This section describes the procedures for terminating a session established by SIP". Furthermore, all procedures for a BYE message is described in this section. Then, it's easy to think that The BYE is not used for an un-answered dialogs. Even into a forked INVITE, I was wondering it has to follow the same rule, which means, UA must not to send BYE even into forked invitations. But, as you assure correctly, the BYE may be used in this case, as writen in RFC, section 15: "The BYE request is used to terminate a specific session or attempted session. In this case, the specific session is the one with the peer UA on the other side of the 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." Thanks for the answer! Leonardo ________________________________ De: Iñaki Baz Castillo <[email protected]> Para: Leo Leo <[email protected]> Cc: "[email protected]" <[email protected]> Enviadas: Terça-feira, 26 de Julho de 2011 8:55 Assunto: Re: [Sip-implementors] BYE before call answer 2011/7/26 Leo Leo <[email protected]>: > This makes no sense to me: > > > > Wrong. BYE can be used to terminate a *specific* dialog (answered or > not answered yet). > > Because... > > > RFC 3261 > > From section 9.1: > If the original > request has generated a final response, the CANCEL SHOULD NOT be > sent, as it is an effective no-op, since CANCEL has no effect on > requests that have already generated a final response. This just says that a CANCEL must not be sent if there is already a final response. If a INVITE creates paralell forking in a proxy and there are N early-dialogs, then the UAC can send a BYE to any of them. > From section 15: > > However, the callee’s UA MUST NOT send a BYE on a confirmed dialog > until it has received an ACK for its 2xx response or until the server > transaction times out. (...) This is speaking about *confirmed* dialogs and BYE sent from the callee to caller. It has nothing to do with the case I'm describing. > Typically, when the user hangs up, it indicates a desire to > terminate the attempt to establish a session, and to terminate any > sessions already created. For the caller’s UA, this would imply a > CANCEL request if the initial INVITE has not generated a final > response, and a BYE to all confirmed dialogs after a final > response. It does not say that a BYE cannot be sent for an early-dialog. Leo, I'm ***sure*** (and it's not the first time I investigate or discuss about it) that a UAC can send a BYE to terminate an early-dialog, just in case there is route-set and remote-target for such early-dialog (if not, that is not an early-dialog yet). Please re-check section 15. -- Iñaki Baz Castillo <[email protected]> _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
