The All-New Switch Book: The Complete Guide to LAN Switching Technology, Second Edition

1.3. LAN Technology Review

In the context of this book, switches are used primarily to interconnect LANs.^[] Historically, dozens of different types and variations of LAN technology have been commercially produced; many have also been formalized and approved by official standards organizations or have become de facto standards through market forces. However, only a small number of these LAN technologies have truly achieved widespread use.

^[] Interconnections among geographically separated LANs using Wide Area Network (WAN) technologies are discussed in Chapter 3.

In this section, we look at the three most popular LAN technologies in the order of their product volume and importance: Ethernet, Token Ring, and the Fiber Distributed Data Interface (FDDI). The vast majority of LAN switches are designed specifically for one or more of these three systems. At the end of the section we briefly consider some other, less-used LAN technologies.

1.3.1. Ethernet

Ethernet was originally conceived and implemented at Xerox Corporation in Palo Alto, California, in 1973. The lab prototype, developed by Dr. Robert Metcalfe (generally regarded as the "father of Ethernet"), operated at 2.94 million bits per second. This Experimental Ethernet was used in some early Xerox products, including the Xerox Alto, the world's first networked personal workstation with a graphical user interface.

During 1979, Digital Equipment Corporation (DEC) and Intel joined forces with Xerox to standardize, commercialize, ...