Hello All, I request clarrification with this cancel - 200(invite) crossover. pcscf in this scenraio acts like a proxy and not a b2bua.
step1 ue--invite-->pcscf--invite-->scscf--invite--> scscf doenst send 100 trying to pcscf. pcscf has sent 100 trying to ue. step2 ue--cancel-->pcscf ue<--200(cancel)--pcscf cancel is not forwarded by pcscf to scscf since 100 trying is not received. step3. meanwhile the callee has sent 200(invite) without 18x directly. ue<--200(invite)--pcscf<--200(invite)--scscf<--200(invite)-- ue--ack-->pcscf--ack-->scscf--ack--> ue sends an ack though it had already sent a cancel. what is the expected bahaviour at pcscf? pcscf knows it has sent 200(cancel) to ue. still it forwards answer 200(invite) to ue since it is not a b2bua. Now who should initiate the release? 1.should the ue release the call(send BYE), knowing that the user already went on hook(sent cancel)? 2.should pcscf make some decission as there exists a dialog at pcscf? for instance the ue doesnt send a bye, the ue is charged since it received an answer: 200(invite) Thanks, Karthik Prabhu _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
