Hi Sourav, Adding some more info as below,
Take practical scenario When 180 ringing is sent means device started ringing and user can send 200 ok for invite at any time. So there might 200 ok before update is sent. This might lead to ghost call scenario. In case of invite without sdp, 200ok contains offer and ack will contain ans. If 100 rel is supported then offer and ans will be exchanged before 200 ok using prack and followed by 200ok for prack. Sent from mobile, Anand Konji On Dec 18, 2015 6:33 PM, "Vivek Batra" <vivek.ba...@matrixcomsec.com> wrote: > AFAIK, both of the flows are incorrect. In first case, if SDP offer is in > reliable provisional response, PRACK must contain SDP answer. UPDATE can be > used any time once SDP offer answer has been done in provisional response > and PRACK. > > Best Regards, > Vivek Batra > > > On Fri, Dec 18, 2015 at 6:15 PM, Sourav Dhar Chaudhuri < > sourav_mi...@yahoo.co.in> wrote: > > > Hi, Please refer the diagram below Callflow diagram > > > > 1) A ------------- INVITE [ Support: 100 rel] without SDP > > ------------------> B > > 2) A <-------------- 180 Ringing [Require: 100 rel] with SDP offer > > ------------ B > > 3) A ---------------- PRACK without SDP > > ------------------------------------------> B > > 4) A <---------------- 200OK for PRACK > > ------------------------------------------------- B > > 5) A ------------------- UPDATE with SDP answer > > ----------------------------------> B > > 6) A <----------------------- 200OK for UPDATE > > -------------------------------------------- B > > 7) A <----------------------- 200OK for INVITE > > ----------------------------------------------- B > > 8) A ------------------------------ ACK > > -----------------------------------------------------------> B > > > > Whether the above Call flow Diagram is a valid one? I mean without > > sending SDP in PRACK [in frame 3]as per RFC 3262, can I send it using > > UPDATE as per RFC 6337? > > Also is the below call flow DIAGRAM is also valid. > > 1) A ------------- INVITE [ Support: 100 rel] without SDP > > ------------------> B > > 2) A <-------------- 180 Ringing [Require: 100 rel] with SDP offer > > ----------- B > > 3) A -------------------- PRACK without SDP > > ------------------------------------------> B > > 4) A <------------------- 200OK for PRACK > > --------------------------------------------- B > > 5) A <----------------------- 200OK for INVITE > > ----------------------------------------------- B > > > > 6) A ------------------------------ ACK with SDP answer > > -------------------------------> B > > Here without sending SDP in PRACK [in frame 3]as per RFC 3262, can I send > > it by ACK? > > > > > > Thanks, > > Sourav > > > > _______________________________________________ > > Sip-implementors mailing list > > Sip-implementors@lists.cs.columbia.edu > > https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors > > > > > > -- > Best Regards, > Vivek Batra > _______________________________________________ > 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
