Hi Bogan-Andrei, To check your scenario: The CANCEL arrives from the UAC before the INVITE has been sent out the proxy to the UAS?
CANCEL is a hop-by-hop message so ideally you would send back a 200 OK to the CANCEL from the proxy and internally stop yourself sending out the INVITE towards the UAS. If that is not possibly, then semantically you should send a CANCEL as soon as you receive the first provisional response for the INVITE you send out. Bear in mind you have to be prepared in that scenario for a 200 OK to the INVITE coming back before the CANCEL is processed by the UAS, and thus be prepared to then BYE the call. So stopping sending the INVITE out would be much easier ;-) Regards, Alan > On 10 Oct 2016, at 10:26, Bogdan-Andrei Iancu <bog...@opensips.org> wrote: > > Hello, > > What should be the correct and most efficient way for a proxy to handle an > incoming CANCEL for a INVITE still under processing. The detailed scenario is > : > > * INVITE is received, the transaction is created, 100 Trying is sent back > * the routing logic is invoked (this may take even 1 minutes due complex I/O > operations to determine the next hop) > * no INVITE was yet sent back > * a CANCEL request is received for the INVITE > > What a proxy should do at this point ? delay the CANCEL and send it further > once the INVITE is also sent out (does not seem to efficient) ? perform the > actual canceling and generate the 487 reply for INVITE (not sure if it is > legitimate for a proxy to do this) ? > > I scan the RFC4361 for any possible hints on the matter, but not much of > luck. Section 9.2 does not apply for a proxy and 16.10 does not cover this > scenario. > > > Thanks and regards, > > -- > Bogdan-Andrei Iancu > OpenSIPS Founder and Developer > http://www.opensips-solutions.com > > _______________________________________________ > Sip-implementors mailing list > Sip-implementors@lists.cs.columbia.edu > https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
