[Serusers] Conferencing questions

I have browsed the mailing lists for information relating to conferencing and I still do not have any authoritative answers to the following questions: 1) I realize that the SEMS has a conferencing module - But from what I understand, each user who wants to participate in a conference would be "dialing" a specific conferencing URI and they would all be bridged and conferencing can take place. Is this correct? 2) A convenient and more realistic scenario is when I am on a call with someone and I'd like to conference in someone. Normally, I would put the first user on hold, Dial a key sequence followed by the phone number of the person I'd like to conference in. Once the person picks up, I can bring the other person on-line and the conference can take place. What does one require to make this happen? From what I read, the User Agents have to support this functionality (mixing?). Can this be done via an ATA or do I need IP Phones? Which ATA/IP Phones supports this? Secondly, I assume I'd still require SEMS to act as a media server? Is this correct? Finally, has someone ever implemented such a solution and would someone be willing to share some thought about it. Thanks in advance __________________________________ Do you Yahoo!? The all-new My Yahoo! - Get yours free! http://my.yahoo.com