In previous versions of Communications Server, it was necessary to maintain a one-to-one ratio of Mediation Servers to gateways. In Lync Server, a single Mediation Server can now control multiple gateways. An additional enhancement is that a Mediation Server can now be deployed as a pool to prevent a single point of failure for a service. This pool can be a standalone pool or it can collocate with an Enterprise Front End pool or the Registrar. This enables an administrator to save hardware by collocating and potentially providing fault tolerance for the Mediation Server or even to improve scalability of the Mediation Server role by providing a load-balanced pool.