Fiber distributed data interface: throughput evaluation with multiple classes of traffic

The fiber distributed data interface (FDDI) standard supports synchronous and asynchronous data transmissions. It allows each station to have multiple classes of asynchronous data, and meets the requirements of different classes by means of a timer-based priority scheme. The performance of a FDDI network carrying multiple classes of traffic is considered. An analytical model is presented to evaluate the throughput of synchronous traffic and asynchronous traffic. The model can be used to evaluate the throughput of individual priority classes and the mean token-cycle time of the network, when the network offered load varies from very low values to high values. The governing equations for the throughput characteristics and mean token-cycle time are strictly functions of network parameters. Simulations are used to verify the analytical model. Simulation results are also used to examine the variation of the mean access delay characteristics of various classes and the token-cycle time distribution of the priority scheme. Limitations of the model are outlined