goutam, This situation is discussed in section 5.3 of:
http://www.ietf.org/id/draft-ietf-sipping-sip-offeranswer-13.txt More inline On 9/22/2010 5:45 AM, goutam kumar wrote: > Hi, > > I'm trying to implement a VOIP call between two endpoints. I'm in a doubt. > > Say Alice and Bob are in a call. Now, > > STEP I > Alice puts Bob on hold. i.e. > > INVITE (RTP-sendonly) > Alice -------------------------------------> Bob > > 200 OK (RTP-recvonly) > <------------------------------------ > > ACK > -------------------------------------> > > > STEP II > After this Bob puts Alice on hold. i.e. > > INVITE(RTP-inactive) > Alice<-------------------------------------- Bob It would be better for Bob to offer sendonly here, though inactive is also permissible if that is what he really wants. > 200 OK (RTP-inactive) > ----------------------------------------> If Bob had offered sendonly, then assuming Alice also still wants the call held, she would answer inactive as shown. > ACK > <---------------------------------------- > > ( If Alice has already put the call on hold, then is Step II possible?? ) Certainly. Why not? > After this sequence of signaling, say Alice takes the call off hold i.e. > > INVITTE(RTP-sendonly) > Alice -------------------------------------------> Bob You say Alice wants to take the call off hold. So she *wants* sendrecv. So she should be offering sendrecv. > 200 OK (RTP ?????) > <-------------------------------------------- If Alice did offer sendonly, and Bob still wants the call on hold, then Bob would have to answer with inactive, since its the only valid answer that doesn't have him receiving. If alice did the better thing of offering sendrecv, then Bob would answer with sendonly, which is valid and what he wants. Thanks, Paul > My Question is:What should bob send as a reply now? > _______________________________________________ > Sip-implementors mailing list > Sip-implementors@lists.cs.columbia.edu > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
