A network node, for example a router, is configured for assigning network parameters for an identified flow of data packets associated with an application service, based on detecting quality of service parameters specified by XML tags within a message between an application server configured for providing the application service and a destination device configured for receiving the application service. The router includes an XML parser configured for parsing XML tags specifying prescribed user-selectable quality of service attributes for a corresponding application service, and an application resource configured for interpreting the prescribed user-selectable quality of service attributes for the application service. The application resource also is configured for assigning the selected network parameters, for transfer of the identified flow of data packets, based on the interpretation of the prescribed user-selectable quality of service attributes for the specified application service.