The Enterprise Edition deployment improves the scalability and availability of an Office Communications Server 2007 R2 deployment by separating the logical operations that a Standard Edition Server performs into individual servers. An Enterprise Edition deployment is referred to as an Enterprise pool because it involves multiple physical servers. An Enterprise pool decouples the back-end server running SQL Server and the SIP registrar and proxy service from the front-end servers. The front-end servers maintain transient information—such as logged-on state and control information for an IM, Web, or Audio/Video (A/V) conference—only for the duration of a user’s session. This configuration is an advantage, because in the event of a system failure, a new front-end server can be quickly brought up to replace it. The front-end servers can further be expanded into specialized server roles by using a command-line option to separate the multipoint control units (MCUs) and Web Components onto separate physical servers. This results in the following two Enterprise pool models:
Enterprise pool, consolidated configuration. In this configuration, shown in Figure 3-3, all front-end servers are configured identically with the same set of server roles. The front-end servers, in addition to running the Instant Messaging (IM) Conferencing Server, can run any of the following additional server roles:
Web Conferencing Server
A/V Conferencing Server
Telephony Conferencing Server
Application Sharing Conferencing Server
Web Components Server
Communicator Web Access Server
Application Server
Figure 3-3 shows both a single consolidated server deployment and a multiple consolidated server deployment. The multiple consolidated server configuration requires a physical hardware load balancer (HLB) to load balance client connections to the front-end servers and Web servers. (A hardware load balancer is not required in the single consolidated server deployment.) In the multiple consolidated server deployment, all front-end servers are configured with the same set of MCUs. These server roles must be configured uniformly on all front ends. All Internet Information Services (IIS) services must be configured in locked-down mode.
Enterprise pool, expanded configuration. In this configuration, shown in Figure 3-4, each server member of the Enterprise pool runs a single server role per physical server. This arrangement enables this configuration to scale beyond the consolidated configuration. In this configuration, the MCUs must be individually addressable. IIS must not be installed on the front-end servers.
The expanded configuration requires a physical hardware load balancer (HLB) to load balance client connections to the front-end servers and Web servers. The HLB’s virtual IP (VIP) address must be manually published in the Domain Name System (DNS). Clients connect to this VIP when signing in to the Enterprise pool. In both configurations, an Enterprise pool can scale up to four front-end servers.
For high availability on the back-end SQL Server, an Enterprise Edition pool deployment can be clustered by using Windows Server Clustering, which is a feature of the Enterprise Edition and Datacenter Edition of Windows Server 2003 and Windows Server 2003 R2, or Windows Server Failover Clustering, which is a feature of Windows Server 2008. Microsoft supports only active-passive SQL clustering for Office Communications Server 2007 R2 Enterprise pool deployments. Active-passive SQL clustering means one SQL node is active while the other SQL node is passive. The front-end servers in the pool are connected to the active node. The passive node takes over when the active node fails. The passive node must be an exact replica of the active node in the system configuration. The SQL Server can be shared with other applications as long as the Enterprise pool database is running on a separate SQL instance. Office Communications Server 2007 R2 supports running the back-end SQL Server on a 64-bit or 32-bit server.
All roles of Office Communications Server 2007 R2 Enterprise Edition require one of the following operating systems:
The 64-bit edition of Windows Server 2008 Standard operating system, or the 64-bit edition of Windows Server 2008 Enterprise operating system
The Windows Server 2003 R2 Standard x64 Edition operating system with Service Pack 2 (SP2), or the Windows Server 2003 R2 Enterprise x64 Edition operating system with SP2
The Windows Server 2003 Standard x64 Edition operating system with SP2, or the Windows Server 2003 Enterprise x64 Edition operating system with SP2
All servers belonging to an Enterprise pool must be running on a Windows Server 2003 SP1 or Windows Server 2003 R2 computer joined to the same Active Directory domain. Thus, Microsoft does not support a scenario in which half of the front-end servers are deployed in domain A and half in domain B, while the back-end servers are deployed in domain C. Also, all servers in an Enterprise pool should be within geographic proximity with 1-gigabit connectivity between front-end servers and back-end servers.
Table 3-2 lists the system requirements for Office Communications Server 2007 R2 Enterprise Edition.
Table 3-2. Hardware and Software Requirements for Front-End 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 network interface card (NIC) recommended |
Operating system (all 64-bit editions and with the latest service pack) | Windows Server 2008 Standard Edition, Windows Server 2008 Enterprise Edition, Windows Server 2003 Standard Edition, Windows Server 2003 R2 Standard Edition, Windows Server 2003 Enterprise Edition, Windows Server 2003 R2 Enterprise Edition, Windows Server 2003 Datacenter Edition, or Windows Server 2003 R2 Datacenter Edition |
Other | Public Key Certificates for Transport Layer Security (TLS), Active Directory domain/forest level Windows Server 2008, or Windows Server 2003 |