The first open Ethernet specification, developed by Digital, Intel, and Xerox, was a great success, in large part because of its simplicity. There was a single medium (thick baseband coaxial cable), a single data rate (10 Mbps), and a set of configuration rules that could be stated in a few sentences. This specification was adopted as IEEE standard 802.3. The commercial success of Ethernet led to a demand for more options, including different media (thin co-ax, twisted pair, and optical fiber) and higher data rates (100 Mbps and now 1 Gbps). This wide range of options for what is still fundamentally a simple system makes it possible to design an Ethernet configuration for virtually any local networking requirement. However, the enormous flexibility of today’s Ethernet brings with it a complex set of configuration rules for the different options and for interconnecting different types of Ethernets. All of the configuration information is available in the IEEE 802.3 documents, which occupy a good-sized bookshelf or two.
Spurgeon’s book is intended to make this mass of configuration information, buried in thousands of pages of documentation, readily and concisely available. The book succeeds admirably. All of the current 10-Mbps and 100-Mbps 802.3 versions are covered. The configuration rules are defined in one short chapter for each version. There is some tutorial information, but the book is primarily a concise exposition of the rules set forth in the standard. A typical chapter defines the network medium, terminator and grounding hardware, transceiver, transceiver cable, and Ethernet interface, as well as defining configuration limits, such as maximum segment length, number of taps per segment, and topology.
The material on the 100-Mbps alternatives is especially helpful, because few people are familiar with the details of these relatively new systems. The chapter on auto-negotiation describes this concept clearly and provides examples that drive home the relevant points. Chapters on multi-segment configurations, bridges, and switching hubs explain how to configure a mixed 10-Mbps/100-Mbps network.
Anyone responsible for designing or installing an Ethernet network will find this an indispensable reference.
