Hello Paul, Why does SIP not recommend a single way to put the UAS on hold? Has there ever been any discussion to provide the hold indication in a separate SIP header in the re-INVITE?
So far I've not seen two SIP endpoints (different vendors) which offer or accept the hold and MOH the same way (some expect c=0.0.0.0 (old way), some respond back with (a=recvonly in response to re-INVITE with a=sendonly), some respond back with (a=sendrecv), some respond back with (a=inactive), some can't handle the second re-INVITE with (a=sendonly, c=MOH server) to connect them to the MOH server. Also, the hold is not bidirectional right? If A puts B on hold, A sends a=sendonly in re-INVITE and B should send a=sendrecv in the response, right? If true, then B can send a re-INVITE to A with a=sendonly, what should the response from A now? How should they take the call off-hold? -Vishal -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Paul Kyzivat Sent: Tuesday, October 17, 2006 8:09 AM To: Retesh Cc: sip-implementors@cs.columbia.edu; gaurav Subject: Re: [Sip-implementors] Query: Call Hold Implementation in SIP/SDP Just to restate the point that I an others are trying to make: THE ANSWERER CANNOT TELL WHETHER THE OFFERER INTENDED HOLD OR ONE WAY MEDIA. You must construct your device so that it doesn't care. If you attempt to distinguish the two you will no doubt encounter interoperability problems. Paul Retesh wrote: > Hi Varun > If I get your point, you are trying to differentiate call on hold with > one way audio. > > Music on hold implemented is using one way audio (sendonly(in offer) > and recvonly(in answer)). > > Practically, hold (without music) is done by exchanging sdp with > attribute as inactive. Also, in case it is done with a=sendonly(in > offer) and a=recvonly(in answer), the UAC may chose not to send any > RTP data at all. > > Also INVITE (sendonly) and reINVITE (sendonly) can be treated as 1 way > audio and call hold respectively. > > Hope this helps. > _______________________________________________ Sip-implementors mailing list Sip-implementors@cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list Sip-implementors@cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
