Abstract: The present invention describes a standard way of defining network service classes, which provide default quality of service levels required for corresponding communication applications. The network service classes provide end-to-end quality of service policies that extend across multiple, disparate communication networks, and the network elements therein. In effect, the network elements within these communication networks are provisioned and network performance is engineered for the various network service classes. The various communication applications will be placed into the most appropriate network service class, which will provide at least the minimum quality of service performance requirements for the communication application. As such, communication applications having similar quality of service requirements will be grouped together, instead of having unique quality of service support in the communication networks.