Performance comparison of service strategies in high speed optical token rings

High-speed local area networks (HSLANs) operate at channel capacities of at least 100 Mbit/s. Taking advantage of the progress in optical transmission technique, the first HSLAN based on a token passing ring, namely FDDI (fiber distributed data interface) has now become commercially available. However, several other strategies to determine the token holding duration at a station may be applied, e.g. single service or exhaustive service. The author evaluates and compares the performance of these token ring protocols for a high-speed backbone network interconnecting possibly heterogeneous conventional local area subnetworks. Every media access protocol under consideration has been shown to work very well for typical numbers of stations (⩽25) in the asynchronous mixed traffic environment. At heavy load the FDDI protocol performs better than the single service strategy due to the educed token rotation overhead, especially for larger values of T-OPR