History of Ethernet, Part I: In the Beginning

Any high-speed tech buff likely has plenty of Cat6 cable bulk laying around — not to mention some older Cat5 cables and Cat5e Ethernet cables. These simple devices have given us the gift of connectivity for as long as many of us can remember.

But have you ever stopped to wonder how these network Ethernet cables came to be? In this two-part series, we outline the history of Ethernet, from its humble beginnings right through to that nest of tangled Cat6 cable bulk lurking behind your computer desk right now.

A Star(LAN) is Born

Ethernet’s official birthday is May 22, 1973, when electrical engineer Bob Metcalfe wrote a memo describing his idea for a local area network (LAN) that could allow multiple computer systems to communicate simultaneously. Like many of our beloved inventions, this one, too, was born in Silicon Valley, where Metcalfe was working for the Xerox Palo Alto Research Center (PARC) to train military personnel in how to use ARPANET, a very early precursor to the world wide web.

Aloha PoE

Metcalfe’s ideas didn’t come out of thin air, however. His system was initially based on the Aloha Network, a radio communications system connecting multiple Hawaiian island channels at once. The Aloha Network’s great strength was that it allowed any station to send signals whenever it wanted; its great weakness was that if two signals were sent at once, it caused a “collision” where neither could get through. Metcalfe invented a way to detect and reroute collisions so that all systems could communicate effectively.

What’s in a Name?

By 1975, Xerox filed a patent on what Metcalfe had first named “Ethernet,” after successfully using it to connect its internal Alto network. The name is a nod to the “luminiferous ether,” a (debunked) theory from the 1800s about the transportation of light. By 1979, Metcalfe had left Xerox to form his own company, 3Com, and Xerox relinquished its brand rights over Ethernet, which allowed for its path to standardization.

One of the most amazing aspects of Ethernet is its lasting longevity in this fast-paced throwaway tech culture of ours (and by “longevity,” we’re not talking about a 500 ft Ethernet cable or the 1,000 to 2,000 insertions you can get out of a standard RJ45 plug). In the next section, we’ll trace the Ethernet of the 1990s and ’90s through its many rapid cycles of evolution to today’s high speed frequency capabilities.

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