Introducing High-Availability

Redundancy for Edge Servers requires just adding more Edge Servers to a pool. There is no logical limit on the number of Edge Servers that can be part of an Edge Server Pool. Load balancing can be done either with DNS load-balancing requests or by using a hardware load balancer.

DNS load balancing is done by entering multiple host records for the Edge Server pool name within DNS. When clients or servers attempt to reach a server that is unavailable, they attempt to use an alternative server.

A hardware load balancer can still be used for Edge Servers in Lync Server, which adds greater load-balancing capabilities at the price of greater complexity. As in prior releases, the internal Access Edge and A/V Authentication Edge interfaces should be load balanced, but the Web Conferencing Edge internal ports should not be load balanced.