My 2 cents inline....
> >About question 2. CANCEL is a message to cancel a request that has been >initiated but not yet completed. Since INVITE is the only message that >has a three-way handshake it is the only message that can be CANCELed. > >For any other message such as OPTION you receive a response and any >response imply that the request has been completed (either accepted with >a 2xx response or rejected with a suitable error response). In neither >of those cases is CANCEL necessary nor suitable. Since you are not >supposed to get 1xx responses from non-INVITE neither should you bother >with CANCEL to cancel them. > > > > Excerpt from RFC#3261: "Because of this, it is most useful to CANCEL requests to which it can take a server long time to respond. For this reason, CANCEL is best for INVITE requests, which can take a long time to generate a response. " Regards, Poojan. >On Mon, 2006-09-25 at 15:39 +0530, jafer sharif mohammed wrote: > > >>HI, >> I have list of two questions for clarification with explanation. >> >> >> 1. why should CANCEL message shouldn't sent prior to arrival of 1XX >>response. >> 2. why will there be a race condition if CANCEL message is send to >>non-invite message. >> >> >> >> waiting for reply. >> jafer. >>_______________________________________________ >>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 > > > _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
