Multirate scheduling for guaranteed and predictive services in ATM networks

We propose a multirate service mechanism that allows a network session to be served at different rates at different times. Applications generating bursty data, such as VBR video, can take advantage of multirate service by requesting a high rate of service for brief periods of bursty arrivals and a lower rate of service at other times. Consequently, an application can improve its delay performance without reserving high bandwidth for the entire duration of a session. Using MPEG video traces from a number of applications, we show that a multirate server outperforms single rate PGPS (packet-by-packet generalized processor sharing) servers in terms of number of connections admitted, while providing the same level of service guarantees. We also investigate the performance of multirate service when service quality need not be guaranteed. We refer to this as predictive service. We show that multirate servers are superior to single rate servers in providing predictive services.