Hi Feng Zhang. This is not the way ''3-way conference'' is normally implemented.
In a ''3-way conference'' User B as example should be able to take part of the voice stream content between User A & User C. You would need a voice media mixer for this purpose ex. at User B side. The voice streams from User A to User C would then pass the media mixer at User B and not pass directly from User A to User C. Hope this answers your question or I have misunderstood what you want. Regards, Michael. -----Original Message----- From: feng zhang [mailto:[EMAIL PROTECTED]] Sent: den 15 augusti 2002 12:17 To: [EMAIL PROTECTED] Subject: [Sip-implementors] 3-way Conference Hi All, I want to fulfill "3-way Conference" in this way : User A------------User B \ / \ / \ / \ / <------------------- RTP channels \ / \ / \ / User C Notes: 1) User A, User B, User C want to "3-way Conference" 2) Every user should setup two RTP channels with the other two users, for examples, User A should setup a RTP channel with User B , and should setup a RTP channel with User C, thus , User A's Voice can be sent to B & C, on the other hand, User B & C 's voice can be received separately on two RTP channels, and User A can hear B & C's voice simultaneously. In this way, I can fulfill "3-way Conference". But I want to know : 1) look at the scenario below: User A User B User C | INVITE | | |------------------>| | | | | | INVITE | |--------------------------------------->| | | How User B INVITE User C , AND let User C know this INVITE is for the same session(3-way Conference) ? 2) in RFC3261 section "13.3.1 Processing of the INVITE" it says: "The INVITE may contain a session description, in which case the UAS is being presented with an offer for that session. It is possible that the user is already a participant in that session, even though the INVITE is outside of a dialog. This can happen when a user is invited to the same multicast conference by multiple other ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ participants. If desired, the UAS MAY use identifiers within the session description to detect this duplication. For example, SDP contains a session id and version number in the origin (o) field. " I want to know whether "the same multicast conference by multiple other participants" it mentions is the way to fulfill a service like "3-way conference"? Thank you! Best Regard! _______________________________________________ Sip-implementors mailing list [EMAIL PROTECTED] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list [EMAIL PROTECTED] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
