Wow, that's a very aggressive b2bua. I believe the timer you're looking for is Timer C, which should be reset by provisional responses (101-199). So if you keep sending 183's they should reset the timer. But I think you may find that humans will hang up long before 45 seconds unless you provide some media indication as well. 45 seconds is a really long time to wait before ringing, imo.
-hadriel > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:sip- > [EMAIL PROTECTED] On Behalf Of vamshi dommeti > Sent: Thursday, April 24, 2008 12:42 AM > To: Paul Kyzivat > Cc: sip-implementors@lists.cs.columbia.edu > Subject: Re: [Sip-implementors] Doubt about SIP User Agent Behaviour > > Thanks Paul , > I got my doubts cleared . Actually I am trying to > interop my UAS with a B2B . So got some issues where the B2B sends > "CANCEL" to UAS after 4 seconds after the UAS sends 183 progress . The > application is a SIP->GSM Switch Engine . So it takes minimum set up > time > of 20-45 seconds to set up the call on GSM network .So got some issues > with > SIP interoperability . May be we should try retransmitting 183 progress > periodically as you said . > > Regards, > Vamshi > > On Wed, Apr 23, 2008 at 7:24 PM, Paul Kyzivat <[EMAIL PROTECTED]> wrote: > > > > > > > vamshi dommeti wrote: > > > > > Thanks Paul , > > > I got the doubts cleared except one . Actually I > need > > > to rephrase the first question . > > > > > > 1)UAC/Proxy Sent a INVITE ,UAS replies with 183 Session Progress . Now > > > what would be the Time which the UAC/Proxy has to wait for the Final > > > Response 200 Ok or Error Response (4xx,5xx) ? > > > > > > > I'm not very good with all those timers, so I can't tell you offhand > > precisely. But there is a timer, on the order of a minute+. If nothing > more > > is heard the transaction times out. If the call is going to pend for a > very > > long time the UAS needs to send a provisional response periodically. > > > > 2)Is Proxy/UAC dependent on User HangUp ( on UAC side) to send a > CANCEL > > > ? > > > > > > > No, because of the above. Eventually the transaction times out. > > > > One more Question , > > > 3) What does the header "Session-Expires: 240;refresher=uac " signify? > > > Does it tell the UAS , that the session will Expire after 240 > seconds > > > ?? > > > > > > > It has to do with expiration of the *dialog*. It doesn't affect the > INVITE > > *transaction*. I don't believe it should be considered to even start > > counting until a *final* dialog is established. (There may be some > question > > about that - conceivably it could start when an early dialog is > established, > > but that would bring up some ugly issues around refreshing, so I don't > think > > so.) > > > > Paul > > > > Regards, > > > Vamshi > > > > > > > > > > > > > > > On Wed, Apr 23, 2008 at 5:21 PM, Paul Kyzivat > <[EMAIL PROTECTED]<mailto: > > > [EMAIL PROTECTED]>> wrote: > > > > > > > > > > > > vamshi dommeti wrote: > > > > > > Hi All, > > > Can anyone please clarify my doubts regarding > > > 1)Is there any Timer as per RFC3261 for Proxy waiting on > > > Provisional > > > Responses with SDP ( e.g: 183 with SDP) before Proxy sends > CANCEL > > > ? > > > > > > > > > A CANCEL is not to be sent until a provisional response is > received. > > > But it doesn't matter what provisional response, or if it contains > > > sdp. > > > > > > > > > 2) What should be the User Agent(UA ) behavior once it receives > a > > > Retransmitted INVITE from a Proxy . Should the UA send Proxy > > > back the Last > > > Send Response ??? > > > > > > > > > The UAS doesn't care if the request came from a proxy or directly > > > from a UAC. When a retransmission is received the last response is > > > to be retransmitted. > > > > > > > > > 3) Does any one know what is the functionality of > *multioption: > > > OPTION-SCE* > > > header in SIP ? > > > > > > > > > I never heard of this. I don't believe it is a standardized header. > > > Probably something proprietary. > > > > > > > > > 4) Is the Behaviour of User Agent be same for "183 with SDP" > > > and "180 > > > with SDP" ? > > > > > > > > > Upon receiving the 180 the UAC may need to generate local ringback. > > > With a 183 it does not. (Assuming no other provisionals have been > > > received.) > > > > > > It seems that some people seem to think that receipt of SDP in a > > > response signals the intent to have in-band ringback, but that is > > > not a valid assumption. There is no explicit signal for in-band > > > ringback. All you can do is assume that if you start receiving > media > > > you may want to play it in preference to locally generated > ringback. > > > > > > Paul > > > > > > > > > Regards, > > > Vamshi > > > _______________________________________________ > > > Sip-implementors mailing list > > > Sip-implementors@lists.cs.columbia.edu > > > <mailto:Sip-implementors@lists.cs.columbia.edu> > > > https://lists.cs.columbia.edu/cucslists/listinfo/sip- > implementors > > > > > > > > > > _______________________________________________ > Sip-implementors mailing list > Sip-implementors@lists.cs.columbia.edu > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
