Optical Local/Metropolitan and Storage-Area Networks

The first generation of local/metropolitan-area networks (LANs/MANs) used copper-based media, spread out typically across a building or a campus under one autonomous administration. With the arrival of optical-fiber transmission, considerable developments took place to enhance the speed and size of these copper-based LANs and MANs, by using optical fibers over various possible topologies, such as bus, ring, and star. We begin with the earlier experiments carried out on optical LANs/MANs in various research groups, and then present some of the standardized optical LANs/MANs, such as distributed queue dual bus (DQDB), fiber-distributed digital interface (FDDI), and different versions of high-speed Ethernet (1/10/40/100 Gbps). Finally, we describe some of the storage-area networks (SANs) augmented by optical fiber transmission, where small locally networked clusters of servers and storage devices are accessed by workstations through LANs such as, HIPPI, ESCON, and fiber channel. (139 words)