An application is a service provided to users of your network for which you want to manage quality of service (QoS). Examples include voice over IP (VoIP) telephony, video on demand (VoD), and gaming. After you have defined an application profile in the CMP database, you can associate it with the MPE devices that will manage that application.
When you offer application services in your network, there are typically many servers in your network that provide that service. These servers are referred to as Application Managers or Application Servers. When these servers are establishing a session that requires quality of service they issue a request to a policy charging and rules function (PCRF). The MPE device provides PCRF for the CMP server.
When defining an application profile in the CMP database, you specify protocol information that is used by MPE devices to identify Application Managers and thus associate each request with its associated application. This lets the MPE device apply policy rules to the request that you have defined for the associated application.