When you remove the old Mediation Server, you need to plan carefully. If the Mediation Server is still in service, you must consider the load on the existing Mediation Server and plan on proceeding with deactivation when users are no longer placing calls that go out through the Mediation Server/media gateway pair. After you have the new Mediation Server in service and handling the load, the easiest method to start the removal of the old Mediation Server is to ensure that the Office Communications Server location profile(s) do not include the old Mediation Server in the route information.