Microsoft® Lync® Server 2013 Unleashed Second Edition

Denial-of-Service Barrier

A compelling reason to deploy a Director is the fact that it provides some isolation for Front End pools from the Edge servers and Internet. If there was a denial-of-service attack against the Edge servers, only the Edge servers and the Director would be affected. This separation allows the Front End pools to continue operating as normal without being impacted by the attack. If a Director was not deployed as the next hop from an Edge server, an attack could potentially impact a Front End pool and cause a much larger disruption to user services.