A COMPARATIVE SIMULATION STUDY OF FDDI AND PRETZEL RING FOR MULTIMEDIA APPLICATIONS

Abstract

The Fiber Distributed Data Interface (FDDI) is, an ANSI standard for high speed fiber optic ring networks. Its media access control (MAC) protocol operates on the basis of timed token ring, and allows transmission of both time critical and normal data. Because of these characteristics it is used in the multimedia environment where there are mixture of synchronous and asynchronous data classes. However for larger networks, FDDI users suffer excessive access delays even under very light traffic because each station has to. capture a token before transmitting. A newly proposed network topology called Pretzel Ring. is very similar to dual ring of FDDI. Its MAC protocol properties include total fairness and very small access delays. Here a modified Pretzel Ring protocol is proposed which is suitable for multimedia applications. A relative performance in terms of throughput, delay and loss rate is evaluated and compared, for both FDDI and Pretzel Ring, in multimedia environment. All the results are obtained using the simulation of MAC layer of FDDI and Pretzel Ring protocols.