Performance measurement of interconnected CSMA/CD LANs

Abstract

A performance measurement study of two Carrier Sense Multiple Access with Collision Detection local area networks interconnected by bridges and fibre optic links is considered. The network is subjected to memory-to-memory read tests with varying loads using artificially generated traffic from personal computer workstations. The tests span a number of configurations with varying loadings on intranetwork and internetwork traffic. The throughput-delay performance of the network is quantified and analysed. The bridge penalty is found to be load dependent. The penalty is high initially, but decreases as the load increases. The decrease can be attributed to the interleaving effect in the bridge processing. It levels off eventually and yields a 10% overhead at the steady state. With mixed loading of intranetwork and internetwork traffic, the bridged network shows a significant improvement in throughput and delay in comparison with an equivalent single network connected by repeaters. © 1989.