Thank you very much!!!
2013/9/13 ankur bansal <abh.an...@gmail.com> > Hi Casey , > > Like Satish mentioned 487 comes immediately but assuming it lost in > network or UAS is RFC2543-compliant(cant generate 487). > > Even then we cannot terminate dialog on getting 200ok(Cancel) due to these > reasons : > > 1. Cancel can be triggered before any provisional response (having to-tag) > comes .Means on receiving 100 trying also Cancel can be trigerred . > Means UAC side dialog is still not (early)established.So how we can > terminate it ? > > 2. As per RFC 3261 , Dialog is terminated only when BYE comes/goes or > failure final response(like 487 in this case ) comes . > > > Now think what can happen if we release dialog on getting cancel 200ok : > > 1. As you might be aware that dialog and transaction state machine run > independtly . > So terminating dialog after getting 200ok of cancel ,will not clean > Invite Tx till final response comes for Invite . > Even if BYE sent in early dialog , it does not impact INVITE > transaction . > Hence sipstack will be waiting for final response for Invite for 64*t1 > . > > Hope this helps . > > Thanks & Regards > Ankur Bansal > > > On Fri, Sep 13, 2013 at 4:25 PM, satish agrawal > <satish.agr...@gmail.com>wrote: > >> Hello Casey, >> >> As per RFC 3261 section 9.2 >> >> If the UAS did not find a matching transaction for the CANCEL >> according to UAS first processes the CANCEL request, it SHOULD >> respond to the CANCEL >> with a 481 (Call Leg/Transaction Does Not Exist). If the transaction >> for the original request still exists, the behavior of the UAS on >> receiving a CANCEL request depends on whether it has already sent a >> final response for the original request. If it has, the CANCEL >> request has no effect on the processing of the original request, no >> effect on any session state, and no effect on the responses generated >> for the original request. If the UAS has not issued a final response >> for the original request, its behavior depends on the method of the >> original request. If the original request was an INVITE, the UAS >> SHOULD immediately respond to the INVITE with a 487 (Request >> Terminated). A CANCEL request has no impact on the processing of >> transactions with any other method defined in this specification. >> >> In your case the UAS SHOULD immediately respond to the INVITE with a >> 487 "Request Terminated" message. >> >> Regards, >> Satish >> >> >> >> >> On Fri, Sep 13, 2013 at 3:37 PM, Guan Xsun <guanxian...@gmail.com> wrote: >> >> > heHi, >> > A SIP client create a dialog by sending INVITE and then will cancel >> it. >> > Whether the dialog can be finished when the dialog receive the 200 OK >> > from cancel or it needs receive the 487 message ? >> > >> > Best Regards! >> > Casey >> > _______________________________________________ >> > Sip-implementors mailing list >> > Sip-implementors@lists.cs.columbia.edu >> > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors >> > >> >> >> >> -- >> Thanks & Regards >> Satish Agrawal >> New Delhi-24. >> _______________________________________________ >> 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
