Sunday , May 26 2024
A useful read for anyone curious about the evolution of Ethernet.

Book Review: ‘Ethernet: The Definitive Guide’ by Charles E. Spurgeon and Joann Zimmerman

Spurgeon and Zimmerman’s Ethernet does a meticulous job of outlining the evolution of the Ethernet standard from the Xerox PARC lab to the present times.

Ethernet has evolved from the first memo written by Bob Metcalfe on May 22, 1973, while working at the Xerox Palo Alto Research Center (PARC) in California, describing the Xerox Altos network system he had invented for interconnecting advanced computer workstations, making it possible to send data between them and to high-speed laser printers. The Xerox Alto was the first personal computer workstation with graphical user interfaces and a mouse pointing device. The PARC inventions also included the first laser printers for personal computers and, with the creation of Ethernet, the first high-speed local area network (LAN) technology to link everything together.

The differentiators of this basic Ethernet over the earlier ALOHA and slotted ALOHA model includes the collision detection mechanism, carrier sense (before transmitting), access to a shared channel by multiple stations (multiple access). This CSMA/CD protocol, combined with a better backoff algorithm, allowed Ethernet to function up to 100% load. This was compared to 18% and 37% provided by ALOHA and slotted ALOHA respectively.

Being a Xerox proprietary technology, the networking technology growth was unlocked only by 1980 when Digital Equipment Corporation (DEC), Intel and Xerox consortium (DIX) announced the first standard for 10 Mb/s Ethernet. The original DIX standard was not copyrighted, allowing an open system.

In the race between computing power and network speed, the 10 Mbps was fairly ahead until the 90s with more traffic being generated by computing systems. By this time the 100 Mbps had been released in the industry along with auto-negotiation feature allowing easy upgrades to the higher speed fast ethernet standard.

The futuristic race for higher speed led to 1 Gbps Ethernet in 1998, 10 Gbps in 2003 and 40 and 100 Gbps Ethernet standard by 2010. The 400 Gbps Ethernet study group was announced in April 2013 for a new IEEE Ethernet standard.

The book discusses how the growth of network technology has also evolved the network topology from the initial bus topology to more robust star and mesh topologies. This leads to the media signaling components in the standard, and the Energy Efficient Ethernet extensions that modify the Ethernet signaling to save power when no data is being sent. Knowing how the media signaling components are organized and what they are called is helpful for understanding the ways Ethernet interfaces are connected to the various media systems and how they send signals over an Ethernet link.

As mentioned in the book, the growth of Ethernet would have been contained without improvements in the basic building block of switches for connecting the multiple devices. Evolutions such as spanning tree protocol and its newer versions allow loop-free path across most complicated networks. The authors give tips for network designers and network troubleshooters for optimal design and trouble free usage of Ethernet technologies. Some of the thumb rules include designing system for reliability and extensive documentation for the network design and devices.

Some of the other topics discussed in this book include Ethernet signaling mechanisms, comparative evolution of SANs and NAS wrt Ethernet or storage network, Power over Ethernet features allowing safe electrical levels without electrician,  evolution of Ethernet networks from within office network to ISP and long range.

To summarize, this book is a useful introduction, providing in-depth analysis on the Ethernet standard. With the troubleshooting and designing tips from the authors and insights with respect to cables and on field devices, Ethernet: The Definitive Guide is a useful read for the network technician and network designer alike.

[amazon template=iframe image&asin=1449361846]

About Ganadeva Bandyopadhyay

One comment

  1. Dr Joseph S Maresca

    The article contains a good rendition on the mechanics of the ethernet!