Please correct if otherwise but IMO as per 3261 Timer C is only applicable for transactions at proxy.
But implementations may have some proprietary timers, equivalent of Timer-C, in UA As already discussed, here dialog at UA can trigger final response or CANCEL in order to terminate the original transaction. Thanks, Harbhanu On Tue, Mar 20, 2012 at 11:29 PM, Worley, Dale R (Dale) <[email protected]>wrote: > > From: M. Ranganathan [[email protected]] > > > > Consider the following two scenarios: > > > > Scenario 1 > > ========= > > Invite Client Transaction sent by UAc creates a Dialog. > > - Sends INVITE > > - Server side sends RINGING periodically once every 30 seconds for ever. > > > > Dialog remains in early state for 3 minutes and times out. > > > > What happens to the INVITE Client Transaction ? Should the SIP stack > > automatically terminate it? > > > > Scenario 2 > > ========= > > Invite Server transaction gets INIVTE. > > Application creates a dialog. > > Application keeps sending 180 periodically once every 30 seconds for > ever. > > Server Dialog times out after 3 minutes in early state. > > What should the SIP stack do with the invite Server Transaction? > > Should it be automatically deleted after the Dialog times out? > > I'm not sure, but I think you believe that the transaction is required > to time out after 3 minutes. That is not true. Searching for "3 > minute" in RFC 3261 turns up a few uses, whose import is that the UAC > times out its request if more than 3 minutes elapse between responses > that it receives. Within RFC 3261, if the UAS sends 180 every 30 > seconds forever, the UAC is not required to terminate the transaction. > > Now, if the UAC's Timer C expires because it doesn't receive responses > for long enough, the UAC should terminate the transaction. As Brett > noted, the UAC can send BYE on the early dialog to terminate just that > early dialog, or it can send CANCEL to cancel that fork of the INVITE, > or all forks of the INVITE. But RFC 3261 only requires that Timer C > be *at least* 3 minutes. > > For humanity's sake, a UAC should terminate a ringing dialog after > some long period of time, and send a 4xx response. But RFC 3261 does > not require that. > > Dale > > _______________________________________________ > Sip-implementors mailing list > [email protected] > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
