Conferencing Servers, also known as multipoint control units (MCUs), manage the content for Office Communications Server 2007 R2 conferences. Office Communications Server 2007 R2 provides the following MCUs:
Each of these server roles communicates directly with clients participating in a conferencing session. Each MCU uses its own protocol, which is optimized for the media it supports. These server roles also synchronize the state of the conference with a process called the focus that runs on the front-end server or Standard Edition Server. The protocol used to control the state of the conference session is called Centralized Conference Control Protocol (CCCP), also referred to as C3P. The focus sends state updates to the Conferencing Server using C3P, which the Conferencing Server listens for over an HTTPS channel.
Conferencing Servers host Web conferences only for organizers that are homed on the Standard Edition Server or Enterprise pool the server is a part of. Users homed on other Standard Edition Servers and Enterprise pools can join as participants to the conference, but they cannot schedule a meeting on a Conferencing Server that is not part of their home server. More details are covered in Chapter 6.
Each of these Conferencing Servers is described in more detail in the following sections. They share the same hardware and software requirements, which are detailed in Table 3-3.
Table 3-3. Hardware and Software Requirements for Conferencing Servers
COMPONENT | REQUIREMENT |
|---|---|
Computer and processor | 64-bit, dual processor, dual core with 3.0-GHz or faster processor |
Memory | 8 GB or more of RAM recommended |
Cache | 1 MB L2 per core recommended |
Hard disk | 2 SCSI hard drives with 72 GB of available hard disk space recommended |
Network | 1-gigabit NIC recommended |
Operating system (all 64-bit editions) | Windows Server 2008 Standard Edition, Windows Server 2003 Standard Edition, Windows Server 2003 R2 Standard Edition, or higher |
Other | Public Key Certificates for Transport Layer Security (TLS), Active Directory domain/forest level Windows Server 2008, or Windows Server 2003 |
Note
To get the most up-to-date information about Conferencing Servers, refer to http://www.microsoft.com/technet/prodtechnol/office/communicationsserver/evaluate/sysreqs/ocs-ee.mspx#EMD.
The IM Conferencing Server is automatically installed on every Standard Edition Server and every front-end server member of an Enterprise pool in both configurations (consolidated and expanded). It cannot be installed separately on a separate physical server. This service enables users to escalate a two-party IM session into a multiparty IM conference.
Escalating from a two-party IM session to a multiparty IM conference involves more than just adding new participants. New state information is involved in an IM conference, and this information must be synchronized across all the parties in an IM conference, such as tracking the roster (that is, a list of participants), determining which participants are conference leaders, displaying the participants’ network of origin, and exposing a set of actions participants can perform (for example, mute, eject, and promote).
The focus controls the management of the conference session, and the IM Conferencing Server enforces it. The focus and the IM Conferencing Server communicate via the C3P protocol. Only port 5061 is required by the IM Conferencing Server.
If you use internal firewalls to compartmentalize your network, the IM Conferencing Server needs to have the same set of ports opened as the Standard Edition Server and Enterprise pool front-end server.
The Web Conferencing Server is responsible for multiplexing the Web conferencing data feed (for example, documents, application sharing, and whiteboard content) from the leader to all participants in the session. Persistent Shared Object Model (PSOM) is the protocol that the Web Conferencing Server uses to share documents and application content in real time to provide that collaborative experience. PSOM uses port number 8057.
The Web Conferencing Server is collocated with the Standard Edition Server and every front-end server in an Enterprise pool in a consolidated configuration. It can also be installed on its separate physical server for higher scalability. Installing a Web Conferencing Server on its own physical server is supported only in an Enterprise pool in an expanded configuration.
Similar to the IM Conferencing Server and the Web Conferencing Server, the A/V Conferencing Server is an MCU for audio and video media. In the case of audio, the A/V Conferencing Server mixes the audio feeds from every participant before returning the mixed audio to each participant. This is computationally intensive. Therefore, it is recommended that you allocate a high-end server for this purpose.
The A/V Conferencing Server uses the Real-Time Audio (RTAudio) codecs for audio and Real-Time Video (RTVideo) codecs for video. Both of these protocols are designed to optimize performance in high-latency, low-bandwidth networks such as the Internet. Two-way communications are peer to peer. Therefore, for voice calls (which make up the large majority of audio communications), the A/V Conferencing Server is not involved.
The Telephony Conferencing Server provides the functionality of joining and controlling an audio conference hosted on a Public Switched Telephone Network (PSTN) bridge from a service provider such as AT&T, Verizon, BT, Intercall, or Premier. When users use the Microsoft Conferencing add-in for Microsoft Office Outlook to schedule a Live Meeting with audio or a conference call, at the time of the conference your desktop phone will be automatically set up to join the audio bridge hosted by your organization’s carrier. The organizer will be able to control the audio from Communicator and perform activities such as muting everyone except the presenter, muting themselves, and removing participants.
The Telephony Conferencing Server is installed automatically as part of the Standard Edition Server and also on the front-end server in an Enterprise pool. It cannot be installed separately as its own service running on a separate physical server.
The Application Sharing Conferencing Server is a new server role in Office Communications Server 2007 R2. This server role provides the platform for desktop and application sharing in Office Communicator 2007 R2 and Office Communicator Web Access R2. The Application Sharing Conferencing Server installs with other conferencing components on the front-end server and manages the data exchange during desktop and application sharing sessions. The Application Sharing Conferencing Server is discussed in further detail in Chapter 6.