An Analysis of Space Priority Queueing in ATM Switches

Abstract

High-speed packet switched networks such as B-ISDN require algorithms to manage the ow of traac into and through the network. Each switching node and network access node is susceptible to overload. End-to-end congestion control algorithms will do much to ensure that overload periods are minimized, but intelligent buuering decisions at internal nodes may aid in managing congestion by shifting cell loss to lower priority traac. This paper investigates how space priority queueing might aid in supporting acceptable quality of service for diierent classes of traac on a high-speed packet switched network. Simulation was used to examine the behaviour of three priority queueing algorithms operating at the output buuer of a switch under realistic traac models, and showed that the performance of these algorithms depends on the shape and type of the traac. The results of this research suggest that space priority algorithms, when combined with other congestion control algorithms, can aid in supporting acceptable quality of service for the users of the network.