Metropolitan Area Networks (MANs): Protocols, modeling and performance evaluation

Abstract

With the continuing success of Local Area Networks (LANs), there is an increasing demand to extend their capabilities towards higher data rates and wider areas. At high data rates and long distances the packet transmission time may become comparable or significantly less than the network propagation delay. For this reason Medium Access Control (MAC) protocols which were developed for LANs are no longer viable. Together with the progress in fiber optic technology, this has given rise to the so-called Metropolitan Area Networks, or MANs. These can span much greater distances than current LANs, and offer data rates in the region of hundreds of Megabit/sec (Mbps). This survey first sketches the problems encountered in using the MAC protocols defined for LANs on higher-speed and longer-distance networks; and then it focuses on two MAC protocols (FDDI and DQDB) developed for MANs by standardization bodies. These two MAC protocols represents two different approaches to overcome the limits of LAN MAC protocols. FDDI represents the evolution of the token passing class of MAC protocols, while the latter is a new brand of MAC protocol with a completely distributed control. This survey focuses on both MAC protocols with particular attention on their performance analysis.