Just to add to all said before ! *INFO *may also be *cancelled* according to rfc-2976 http://www.rfc-archive.org/getrfc.php?rfc=2976 If a provisional response is received ! i am not quite sure what is the use and why one would do so !
Apoorva On 9/25/06, Poojan Tanna <[EMAIL PROTECTED]> wrote: > > 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 > _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
