On Resource Management and QoS Guarantees For Long Range Dependent Traffic

It has been known for several years now that variable-bit-rate video sources are strongly auto-correlated. Recently, several studies have indicated that the resulting stochastic processes exhibit long-range dependence properties. This implies that large buffers at intermediate switching points may not provide adequate delay performance for such classes of traffic in Broadband packet-switched networks (such as ATM). Given these observations, and the need to provide guaranteed maximum-delay and delay-jitter bounds, and low cell-loss probabilities to applications, the solution appears to be (a) allocating higher rates if the distribution tails are large, (b) using multiplexing to narrow these tails, (c) applying a per circuit frame-clock in conjunction with an active cell-discard strategy to deal with long-range dependence. Strategy (c) is a version of the Stop and Go Stop queuing that does not require tight deterministic rate specifications, but provides maximum-delay and delay-jitter bounds over multiple hops as in the original proposal. The combined strategy is a hybrid between packet switching and circuit switching technology. This research was supported in part by the National Science Foundation under grant NCR-9396299. This is a revised and extended version of a paper that is to be presented at the IEEE Infocom '95 Conference in Boston in April 1995