1. Start Topology Builder: Click Start, click All Programs, click Microsoft Lync Server 2013, and then click Lync Server Topology Builder.

2. In Topology Builder, in the console tree, expand the name of the site for which you want to define a Front End pool.

3. In the console tree, right-click the type of Front End pool you want, and then click New Front End pool...

4. Navigate through the Define New Front End Pool wizard until you reach the Select collocated server roles page.

5. In Select collocated server roles, check the option Collocate Mediation Server.

   Note:

   If the type of Front End pool you selected is the Enterprise Edition, then the Mediation Server component will be installed on all the Front End Servers of that Front End pool. The Next hop pool used by the Mediation Server will be the Front End pool where the Mediation Server is collocated on. The Edge pool used by the Mediation Server will be the same Edge pool associated with the Front End pool where the Mediation Server is collocated on.

6. Click Make Default to use this Front End pool to route calls from Microsoft Office Communications Server 2007 R2 to the PSTN.

7. Click Finish when you are finished associating one or more peers to the Front End pool.

   Note:
   Before you proceed to the next step in the Enterprise Voice deployment process, make sure that the Mediation Server pool (i.e. Front End pool with the Mediation Server component collocated) is using the FQDNs that you specified.

8. Next, follow the procedures in Publish the Topology in the Deployment Guide documentation to add the Mediation Server to your topology before proceeding to the next step of modifying the listening ports of the Mediation Server if needed. You must publish your topology each time you use Topology Builder to define or modify your topology.

1. Start Topology Builder: Click Start, click All Programs, click Microsoft Lync Server 2013, and then click Lync Server Topology Builder.

2. In Topology Builder, in the console tree, expand the name of the site for which you want to define a Mediation Server.

3. In the console tree, right-click the Mediation pools node, and then click Mediation Server pool.

4. In Define New Mediation Pool, type the Mediation Server pool fully qualified domain name (FQDN).

5. Next, do one of the following:

   • If you want to deploy multiple Mediation Servers in the pool to provide high availability, then select Multiple computer pool.

     Note:
     You must deploy DNS load balancing to support Mediation Server pools that have multiple Mediation Servers. For details, see the Using DNS Load Balancing on Mediation Server Pools section of DNS load balancing in the Planning documentation.

   • If you want to deploy only one Mediation Server in the pool because you do not require high availability, then select Single computer pool. Skip the following step.

6. If you selected Multiple computer pool in the previous step, on the Define the computers in this pool item, click Computer FQDN, type the FQDN of each server in the pool, and then click Add. Repeat this step for all other Mediation Servers that you want to add to the pool. When you have defined all the computers in the pool, click Next.

7. On the Select the next hop page, click Next hop pool, click the FQDN of the Front End pool that will use this Mediation Server pool, and then click Next.

8. On the Select an Edge Server page, do one of the following:

   • If you want to provide PSTN connectivity to external users enabled for Enterprise Voice, under Select Edge Pool used by this Mediation Server, click the FQDN of the Edge Server pool that will use this Mediation Server pool to provide PSTN connectivity to those external users, and then click Next.

   • If you do not plan to enable external users for Enterprise Voice, or if you do not want to provide PSTN connectivity to users when they are outside the internal network, click Next.

9. Next, follow the procedures in Publish the Topology in the Deployment documentation to add the Mediation Server to the topology. You must publish your topology each time you use Topology Builder to build or modify your topology so that the data can be used to install the files for servers that are running Lync Server. Then continue to the next steps to modify the listening ports on the Mediation Server, if necessary.

1. Start Topology Builder: Click Start, click All Programs, click Microsoft Lync Server 2013, and then click Lync Server Topology Builder.

2. In Topology Builder, in the console tree, expand the Mediation pools node, and right-click the Mediation Server previously created.

3. By default, the SIP listening ports on the Mediation Server are 5070 for TLS traffic from Lync Server, 5067 for TLS traffic from peers (gateways, PBXes, or SBCs). TCP port is disabled by default. You must enable TCP port if you have gateways that do not support TLS.

4. Specify the desired TLS or TCP listening port range the Mediation Server will accept incoming connections from PSTN gateways.

   Note:
   Entering a TCP port range is not required if Enable TCP port is not checked. This setting is optional.

Next, Define a Gateway in Topology Builder and install the files on each Mediation Server in the pool by following the procedures in Install the Files for Mediation Server.