A Method for Analysing the Performance Aspects of the Fault-Tolerance Mechanisms in FDDI

The high speed Fibre Distributed Data Interface is becoming an accepted standard for many real-time communication networks. One of its real-time applications supporting aspects is that the fault tolerance mechanisms are fast and initiated automatically. Nevertheless, occurring errors can have great influence on performance measures such as the probability of missing a deadline. In this paper we analyse the ability of the error recovery mechankms to make FDDI satis& real-time performance constraints in the presence of errors. A complicating factor in these analyses is the rarity of the error occurrences, which makes direct simulation unattractive. Therefore, we have developed a fast simulation technique, called Injection Simulation, which makes it possible to analyse the performance of FDDI including its fault tolerance behaviour. In this paper we discuss the implementation of Injection Simulation for polling models of FDDl and show simulation results.