Our research concerns the architectural design for quality of service and its implementation in routers and hosts. We believe that advanced services may be built from a small set of basic services. The network services are combined and augmented by end-system functionality to provide the communication support needed by modern multimedia applications. A network service consists of jointly designed traffic and error controls. We are also developing a system to monitor the operational quality in networks.
The main design principle is to move functionality and per-session state from the network nodes out to the hosts. Such decentralisation improves scalability and eases QoS support for multicast and mobility. We anticipate that a future Internet will have an optical backbone based on dense wavelength-division multiplexing, possibly with packet switching, and wireless access networks. An architecture that avoids processing in the network nodes is better suited for a network based on optical rather than electronic switching. Our research on the wireless edge relates to handover issues for Wi-Fi local area networks.