Mediation Server Role Collocation

In prior versions of OCS, the Mediation Server was a dedicated role and required a one-one relationship between the server and the gateway. OCS configuration enabled only a single, next-hop configuration from the Mediation Server to the media gateway (PBX, PSTN, and so on). Although certain gateway manufacturers were able to load-balance calls from the gateway to OCS, OCS was limited to only the single next hop. In Lync Server, the mediation role now runs on the Front End Server as a service. This concept of mediation server collocation provides tangible benefits from a topology, administrative, and user perspective.

With Lync Server, each Front End Server can have its own mediation service, enabling pools to route to gateways instead of the mediation servers. This enables multiple mediation servers to route to the same gateway or multiple gateways to route to a single mediation service.

This capability provides tremendous flexibility to design engineers and enterprises with a large number of PBX/PSTN trunks at a single site or many smaller sites. In previous versions of OCS, these scenarios required a mediation server at each location. In addition to a tangible reduction in servers, this topology change provides greater resiliency, more flexible routing choices, and more options for media flow.