When adding high-availability to a Lync Server Edge Server deployment, an organization must make a decision about how it will provide load-balancing features. The only options available for load-balancing Edge Servers are to use Lync’s native DNS load-balancing feature or to leverage a hardware load-balancing solution.
Windows Network Load Balancing (NLB) is not supported for load balancing any of the Lync Server roles, including Edge Server features.
DNS load balancing seems like an attractive feature at first because it requires very little configuration, but does have some minor limitations. Organizations should review these limitations and then make a decision about whether a hardware load balancer ...