The next step in deploying a Mediation Server is to edit the existing Lync Server topology. To edit the topology follow these steps:
If the Topology Builder is not already installed on the local computer or another computer in the environment, it can be installed from the Lync Server 2013 media.
1. Open the Lync Server Topology Builder.
2. When prompted to select the source topology, select Download Topology from Existing Deployment to retrieve the current topology.
3. Enter a location to which to save the temporary topology file.
4. Expand the Site node where the Mediation Server will be deployed.
5. Expand the Lync Server 2013 node.
6. Right-click on the Mediation Pools node and select New Mediation ...