Call Flows Among Conference Components

Scheduling a Conference

The sequence of steps by which this familiar scheduling model enables client and server cooperate to create a scheduled conference is as follows:

1. Using organizer input, the scheduling client (Outlook) generates a unique conference ID.

2. The scheduling client contacts the Focus Factory on the conferencing server (either Standard Edition or an Enterprise Edition Front End Server) and requests a new meeting. This request and subsequent meeting commands that are exchanged between client and servers use C3P over SIP.

3. The Focus Factory determines whether the organizer is authorized to create a conference. If so, the Focus Factory returns a unique conference SIP URI to the scheduling client.

4. The scheduling client, after receiving the conference SIP URI from the Focus Factory, uses it to create a Conference Join URL, which includes the conference ID, conference key, and parameters indicating whether the conference is audio only or a full collaborative meeting.

5. The scheduling client sends an e-mail invitation to all meeting participants, including the organizer. This invitation contains the Conference Join URL, which participants click to join the conference.

Creating an Unscheduled Conference

The sequence of steps by which an unscheduled conference is created is similar to that for a scheduled conference:

1. The scheduling client (Office Communicator 2007) generates a unique conference ID.

2. The scheduling client contacts the Focus Factory on the conferencing server (either Standard Edition or an Enterprise Edition Front End Server) and requests a new meeting.

3. On the server, the Focus Factory creates a new instance of the Focus for the scheduled conference and returns a unique conference SIP URI to the scheduling client. Depending on the media that is specified for the conference, the newly instantiated meeting Focus contacts the appropriate conferencing server factory with requests to allocate new Conferencing Servers for the meeting.

4. The scheduling client, after receiving the conference SIP URI from the Focus Factory, uses it to create a Conference Join URI, which includes the conference ID, conference key, and parameters indicating whether the conference is audio only or a full collaborative meeting.

When a user clicks the Conference Join link in the invitation, the following events occur:

1. The Live Meeting 2007 client starts on the user's computer.

2. The Live Meeting client automatically locates the appropriate Office Communications Server according to the users SIP URI and sends a SIP INVITE message to the Focus.

3. The Focus challenges the user's credentials by using NTLM or Kerberos authentication. Federated users are authenticated by the trusted-domain token in the message header. If the user does not pass authentication, the Focus uses digest authentication to request the conference key, which was generated at conference creation for the purpose of authenticating anonymous users.

4. If the user passes authentication, the client subscribes to the conference package and sends invitations to join the appropriate conferencing servers for each media type.

Joining a Conference

A meeting invitation contains the following elements:

• The Conference Join URI

• A link for first-time participants to download the Live Meeting 2007 client. The invitation might contain two such links: one for internal and another for external users.

• Audio instructions

• Lists of participants.

• Troubleshooting information, including the following:

  • Instructions for installing and running the Live Meeting 2007 client

  • Meeting join information

  • A customizable link to a Web page containing troubleshooting information or two links if internal and external users are to access separate troubleshooting sites.