Distributed multimedia systems require quality of service at various abstraction levels. At the application level, QoS describes communication in terms of application specific processing units, e.g. frames. At the transport level QoS is used to describe the communication load for the transport system. An architecture integrating the various levels is presented. The architecture provides the framework for performing negotiation of QoS and resource reservation. It includes the specification of a programmer interface and a flowspec carrying QoS information between communication nodes.