The internal edge of a Mediation Server should be configured to correspond to a unique static route that is described by an IP address and a port number. This IP address must be the one corresponding to the IP address from the DNS resolution of the FQDN of the Mediation Server. The default port is 5061.

The external edge of a Mediation Server should be configured as the internal next-hop proxy for the media gateway. It should be identified by a unique combination of IP address and port number. The IP address should not be the same as that of the internal edge, and the default port is 5060.

When configuring Mediation Server, you are advised to accept the default media port gateway range of 60,000 to 64,000. The default range media port range enables the server to handle up to 1,000 simultaneous voice calls. Reducing the port range greatly reduces server capacity and should be undertaken only for specific reasons by an administrator who is knowledgeable about media port requirements and scenarios. For this reasons, altering the default port range is not recommended.

Organizations that use IPSec for packet security are advised to disable it for media ports because the security handshake required by IPSec delays call setup. IPSec is unnecessary for media ports because SRTP encryption secures all media traffic between the Mediation Server and the internal Communications Server network.

Media Gateway

Depending on the gateway vendor, there are potentially many attributes that must be set, but to use the gateway for Enterprise Voice, port 5060 must be configured as the listening port that is used for TCP connections to the Mediation Server.