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Pool Configurations

Microsoft Office Communications Server 2007 and Microsoft Office Communications Server 2007 R2 will reach end of support on January 9, 2018. To stay supported, you will need to upgrade. For more information, see Resources to help you upgrade your Office 2007 servers and clients.

An Office Communications Server 2007 pool consists of one or more Front End Servers that provide IM, presence, and conferencing services and are connected to a SQL Server database for storing user and conference information. Depending on the pool configuration, the database might reside on the same server. In addition, certain conferencing components might be deployed on the same physical computer, depending on the chosen pool configuration.

Office Communications Server 2007 offers three pool configurations: one Standard Edition configuration and the consolidated and expanded Enterprise Edition configurations. Both Enterprise Edition configurations consist of identical Front End Servers that are connected to a separate dedicated Microsoft SQL Server 2005 back-end database. (In an Enterprise pool, the Back-End Database must be on a dedicated computer, separate from all Enterprise Edition servers.)

Standard Edition Configuration

As shown in Figure 7, a Standard Edition server hosts all necessary services on a single Front End Server. Because it requires a minimal hardware investment and minimal management overhead, the Standard Edition configuration is ideal for small and medium-sized businesses and for branch offices. It is intended for deployments with fewer than 5,000 users either in total or at a particular location where high availability is not a requirement.

Figure 7. Standard Edition configuration

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Enterprise Edition: Consolidated Configuration

Enterprise Edition: Consolidated Configuration is a pool configuration in which all server components are collocated on the pools Front End Servers (with the exception of the Back-End Database, which must reside on a separate dedicated computer). Consolidated Configuration provides scalability and high availability and yet is easy to plan, deploy, and manage.

Figure 8. Enterprise Edition: consolidated configuration

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Enterprise Edition: Expanded Configuration

Enterprise Edition: Expanded Configuration offers maximum capacity, performance, and availability for large organizations. As shown in Figure 9, in Expanded Configuration, Internet Information Services (IIS), the Web Conferencing Server, and the Audio/Video Conferencing Server are installed on dedicated computers separate from the pools Front End Servers. Expanded configuration enables organizations to scale up audio/video or Web conferencing requirements independently from other Enterprise Edition server components. For example, if an organization's audio/video traffic increases more rapidly than other traffic, the organization can meet this increase by deploying only additional Audio/Video Conferencing Servers rather than entire Front End Servers.

Figure 9. Enterprise Edition: expanded configuration

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As the figure shows, the IM Conferencing Server and Telephony Conferencing Server are located on the Front End Server, even in the Expanded Configuration, while the Web Conferencing Server, A/V Conferencing Server, and IIS are installed on separate, dedicated computers. In the figure, the Front End Servers are connected to one hardware load balancer and the servers running IIS (Web Components Servers) are connected to a separate load balancer. You can, however, also use the same hardware load balancer for both the Web Components Servers and the Front End Servers.

The Office Communications Server 2007, Standard Edition or Enterprise Edition, Front End Server is responsible for the following tasks:

  • Handling signaling among servers and between servers and clients

  • Authenticating users and maintaining user data, including all user endpoints

  • Routing VoIP calls within the enterprise and to the PSTN

  • Initiating on-premise conferences and managing conference state

  • Providing enhanced presence information to clients

  • Routing IM and conferencing traffic

  • Managing conferencing media

  • Hosting applications

  • Filtering SPIM (unsolicited commercial IM traffic)

The following sections provide a technical overview of the Front End Server components that enable conferencing and VoIP.