REAL TIME PERFORMANCE OF CONVENTIONAL AND EARLY TOKEN RELEASE TOKEN RING PROTOCOLS

Abstract

Token Ring LANs are widely used for Interconnecting computer systems.Therefore it is studied extensively to improve its performance.Two different token ring protocols are proposed by IEEE.802.5.One Is the original token ring protocol named as Conventional Token Release (CTR) and other is a recent extension to CTR protocol that is called as Early Token Release (ETR) protocol. Here Real Time performance of these two protocols is discussed.A simulation program Is. developed for these two protocols under real time traffic and their performance is evaluated .Comparison is done between the two from schedulability point of view. Simulation is also used to select the network parameter such as optimum packet size, length of the ring and to quantify the effects of parameter such as network size on schedulability. Petri net representation is also given for the two protocols.