Introducing High Availability

Redundancy for Edge Servers requires just adding more Edge Servers to a pool. Like a Front End pool, up to ten servers can be defined in an Edge Server pool. Load balancing can either be done 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 will attempt to use an alternate 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.