Call admission control (CAC)

Call admission control is a service built into the Lync Server. It limits the number of simultaneous calls and real-time connections, so the available bandwidth is managed, and the quality of the calls stays assured.

CAC is configured through the New Bandwidth Policy dialog; we then have to define the bandwidth limits in a dedicated policy as follows:

As we have seen, no special equipment is required to enforce CAC, and it supports control on audio, video, and conferencing.

The policy is based on the location of the client, so we are able to manage quality of service (QOS) in a dynamic manner, according to the changing connection point of our users. In Lync, it is necessary to define the subnets we use in our network in order to use this feature.