On the performance of topologies and access protocols for high-speed LANs and MANs

Abstract

Abstract The performances of several topologies and access protocols proposed for high-speed local and metropolitan area networks (LANs and MANs) are compared using simulation models. First, FDDI (Fiber Distributed Data Interface), DQDB (Distributed Queue Dual Bus), CRMA (Cyclic Reservation Multiple Access), and CRMA-II (the latest evolution of CRMA) are compared in a uniform traffic scenario. Second, the slot reuse technique is studied for DQDB and CRMA, showing that remarkable gains in performances can be obtained, particularly in the case of non-uniform traffic distributions. Finally, meshed topologies that allow a further exploitation of spatial reuse are considered, focusing on Manhattan Street Networks (MSNs). Numerical results indicate that the massive exploitation of spatial reuse permits significant advantages in terms of user throughput and access delay to be obtained, with a node complexity comparable to that of bus or ring topologies.