UNITE: a framework for flexible QoS management
Gísli Hjálmtýsson, Kadangode K. Ramakrishnan · 2002
UNITE, our proposed lightweight signaling protocol for ATM, allows us to flexibly support QoS, while achieving efficiency for those flows that do not require substantial customization. UNITE efficiently supports a large number of best-effort flows by separating out the connectivity requirements from QoS processing. Connection setup is performed on the signaling channel while QoS processing is performed in-band. One of the important advantages of this approach is the ability to have QoS signaling initiated by any of the end-systems. Hence, we can smoothly support the RSVP-style of QoS setup by the receiver as well as UNI (User Network Interface)-style QoS setup by the source. The controller is separated from the high-speed switching. Most of the functions for QoS support are performed by the controller. By placing all the signaling for QoS negotiation in-band, UNITE isolates the QoS processing of one connection from another. We can now begin to have individual connections requiring different amounts of customization of their flows, ranging from simple best-effort connections that do not require any customization, to complex application-specific policies and processing that may be required in the network. In-band signaling allows us to provide considerable flexibility for future evolution of QoS support in the network. In-band signaling also removes from the common signaling channel the complexity of describing all the connection-specific information. This enables the signaling channel to have high performance for connection setup, where performance is critical.