A functional architecture for end-to-end quality-of-service in a multi-domain network

This paper describes an architectural framework for end-to-end QoS in large multi-domain networks, where int-serv and diff-serv are both deployed to provide service differentiation. The described framework is intended to ease the deployment of new QoS-sensitive infrastructures and to expedite the interoperability among heterogeneous domains. Unicast and multicast traffic are both considered. For both we characterize the functional modules which compose the architecture and their relationships. We identify the architectural and communication issues which arise when multicast traffic traverses a multi-domain network and we show how the architecture must be modified to support that traffic under different end-to-end QoS requirements. We finally report some initial performance evaluations obtained by implementing the multicast architecture for CBR traffic in the frame of a simulation environment based on the ns simulation package. This paper is the first attempt to provide a common and homogeneous architectural framework to deal with multicast communications with QoS guarantees in a multi-domain network. This is demonstrated to be very helpful to coordinate more specific analysis through simulations and to deploy a testbed environment which allows more extensive evaluations by modularily combining software objects available from the public domain.