Performance characteristics of a broadband PC LAN: an experimental study

Abstract

An experimental study has been carried out to evaluate the performance of a broadband PC LAN: the IBM PC Network. The network is subjected to tests with varying loads using artificially generated traffic from workstations. The tests span from the region of high performance to the heavy overload limits where performance is degraded. The throughput and delay characteristics are quantified with varying packet lengths and offered loads. The throughput shows a stable behaviour in the heavy overload region where packet collisions are bounded to be about 2.5 collisions/successful packet transmission. Packet delay is minimal at light load but rises sharply when the throughput saturates. The CSMA/CD protocol is seen to be fair to all contenders. The measurements are compared to predictions of existing analytical models. The result shows a close agreement with the advanced slotted model. © 1987.