Recently I have received queries on helping troubleshoot Conference Scenarios:

As a start it is important to know which component is problematic ? Client, Front-End, Focus, MCU, ..

These links below will help with getting started on determining the core components and which ones may be an issue.

[MS-CONFAS]: Centralized Conference Control Protocol: Application Sharing Extensions

Specifies the Centralized Conference Control Protocol: Application Sharing Extensions, which are extensions to the Centralized Conference Control Protocol that can be used to integrate application sharing conference modes within the framework defined in the [MS-CONFBAS]: Centralized Conference Control Protocol: Basic Architecture and Signaling Specification.

Click here to view this version of the [MS-CONFAS] PDF.

[MS-CONFAV]: Centralized Conference Control Protocol: Audio-Video Extensions

Specifies the Centralized Conference Control Protocol: Audio-Video Extensions, which is a set of extensions for setting up multi-party, multi-modal conferences. This protocol specifies the conferencing system architecture and the protocols used between Microsoft Office Communicator 2007 Service Pack 1 and Microsoft Office Communications Server 2007 Service Pack 1.

Click here to view this version of the [MS-CONFAV] PDF.

[MS-CONFBAS]: Centralized Conference Control Protocol: Basic Architecture and Signaling Specification

Specifies the Centralized Conference Control Protocol: Basic Architecture and Signaling, which is a set of extensions for setting up multi-party, multi-modal conferences. This protocol specifies the conferencing system architecture and the protocols used between Microsoft Office Communicator 2007 Service Pack 1 and Microsoft Office Communications Server 2007 Service Pack 1.

Click here to view this version of the [MS-CONFBAS] PDF.

[MS-CONFIM]: Centralized Conference Control Protocol: Instant Messaging Extensions

Specifies the Centralized Conference Control Protocol: Instant Messaging Extensions, which is a set of extensions for setting up multi-party, multi-modal conferences. This protocol specifies the conferencing system architecture and the protocols used between Microsoft Office Communicator 2007 Service Pack 1 and Microsoft Office Communications Server 2007 Service Pack 1.

Click here to view this version of the [MS-CONFIM] PDF.

[MS-CONFPRO]: Centralized Conference Control Protocol: Provisioning Specification

Specifies the Centralized Conference Control Protocol: Provisioning, which is a set of extensions for setting up multi-party, multi-modal conferences. This protocol specifies the conferencing system architecture and the protocols used between Microsoft Office Communicator 2007 Service Pack 1 and Microsoft Office Communications Server 2007 Service Pack 1.

Click here to view this version of the [MS-CONFPRO] PDF.

[MS-CONMGMT]: Connection Management Protocol Specification

Specifies the Connection Management Protocol, which describes outbound proxy auto-discovery mechanism for the client. This protocol also defines the negotiation mechanism and data format for sending keep-alive messages between the client and server, and the certificate requirements for establishing Transport Layer Security (TLS) connections.

Click here to view this version of the [MS-CONMGMT] PDF.

This is another useful reference, Every Office Communications Server 2007 R2 conference has a similar lifecycle, which is described at a high level in this section.

http://technet.microsoft.com/en-us/library/dd572357(office.13).aspx

We will follow up with a very specific Conference Scenario troubleshooting for a Service Request ... Stay tuned :-)