Class-specific quality of service guarantees in multimedia communication networks

We consider the problem of quality-of-service (QoS) provisioning in modern high-speed, multimedia, communication networks. We quantify QoS by the probabilities of loss and excessive delay of an arbitrary packet, and introduce the model of a multiclass node (switch) which provides network access to users that may belong to multiple service classes. We treat such a node as a stochastic system which we analyze and control. In particular, we develop an analytical approach to estimate both the delay and the bu!er over#ow probability per service class, based on ideas from large deviations and optimal control. We exploit these performance analysis results by devising a call admission control algorithm which can provide per class QoS guarantees. We compare the proposed approach to alternative worst-case and e!ective bandwidth-based schemes and argue that it leads to increased e$ciency. Finally, we discuss extensions to the network case in order to provide end-to-end QoS guarantees. ( 1999 Elsevier Science Ltd. All rights reserved.