Step 7. Plan for Deploying Load Balancers

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.

Before you deploy Office Communications Server 2007, you should have one or more hardware load balancers in place and configured appropriately. A load balancer performs the critical role of delivering load distribution and high availability across multiple servers. This section provides the information to help you configure load balancers for your Office Communications Server 2007 deployment.

Hardware Load Balancers

Hardware load balancers are devices that often combine an Ethernet layer 3 switch with the ability to load balance, and switch multiple streams of traffic, such as client to server, server to server, server to Active Directory, server to DNS, and management access to server pool. They are sophisticated devices that feature extensive monitoring capabilities; operate at multiple gigabit levels; generate powerful load balancing metrics that can be configured to route traffic based on such conditions as least connections on a server, the latency times of servers, weighted round robin or weighted least connections. A load balancer exposes a single VIP (virtual IP) address to clients so that they do not directly access individual Enterprise Edition Front End Servers. A load balancer is not required to decrypt TLS (Transport Layer Security) or parse SIP messages.

General Requirements

An Office Communications Server 2007 Enterprise pool consisting of more than one Front End Server requires a hardware load balancer. If you are deploying a Standard Edition Server or a single Enterprise Edition Front End Server, a load balancer is not required. A hardware load balancer is also required for arrays of Office Communications Server 2007 Edge Servers or an array of Standard Edition Servers configured as a Director. These requirements are summarized in the following table.

Table 76 Hardware load balancer requirements for Office Communications Server 2007

Deployment Load Balancer Requirement

Standard Edition Server

Load balancer not required

Enterprise Pool with multiple Front End Servers

Hardware load balancer required

Enterprise Pool with single Front End Server

Load balancer not required

Array of Directors

Hardware load balancer required

Array of Edge Servers

Hardware load balancer required

Note

Office Communications Server 2007 does not support the use of Windows Server 2003 Network Load Balancer in any production deployments.