Hi Jerry, please see my comments in line.
2007/9/12, Jerry Yin <[EMAIL PROTECTED]>: > > I think there are two ways to invoke a conference. One is to invoke the > conference by the conference server. The other is ad-hoc conference invoked > by the participants. The > draft-ietf-sip-uri-list-conferencing was trying to solve > the problem by initiating a conference from the server. > Here's what I think for the ad-hoc conference. > Participants: A calls B (a UA or a conference room) and put B on-hold, and > then A calls C. Now A presses the conf button. > 1. If B has a conference room url, A will transfer C to B (by REFER), as > some of you discussed already. It actually is supported by some companies > already as I know. > 2. But if B is a UA, when the conf button is pressed, the only SIP messages > send out by A is the re-Invite (off-hold) to B since most SIP phones support > 3-way conference locally. Then A will do the audio mixing locally. So far I > didn't find any solution to transfer the local 3-way conference to a > centralized conference yet. Currently in our system, we adopted the "Join" > header (RFC3911). When A sends the re-Invite to B, it also includes a Join > header contains the C's dialog info. The B2B server will translate the Join > to a centralized conference. It will Invite C with a Replace header to [Peili] Solution 2 is interesting, but as my interpretation of RFC3911, it seems join header should only be added in a new INVITE. I copy the text here "The UAC places the Call-ID, to-tag, and from-tag information for the target dialog in a single Join header field and sends the new INVITE to the target." > replace the session between A and C. C will sends a BYE to A. The server > will update the media to A and B (reInvite). Then all three parties are in > the centralized conference room. > I hope the new RFC for conference also capture the behavior described in 2. > Whether it's Join header or something else. The user should be able to call > someone first and then decided to setup a conference.Jerry > _______________________________________________ Sip mailing list https://www1.ietf.org/mailman/listinfo/sip This list is for NEW development of the core SIP Protocol Use [EMAIL PROTECTED] for questions on current sip Use [EMAIL PROTECTED] for new developments on the application of sip
