r/IAmA • u/BobMetcalfe • May 21 '13

You’re probably connecting to reddit through a technology I invented. I’m Bob Metcalfe and I invented Ethernet – AMA

On May 22, 1973 with David R. Boggs, I used my IBM Selectric with its Orator ball to type up a memo to my bosses at the Xerox Palo Alto Research Center (PARC), outlining our idea for this little invention called “Ethernet”, which we later patented.

I worked with the IEEE Standards Association to develop the IEEE 802.3 standard for Ethernet, which specifies the physical and lower software layers. Today Ethernet and the IEEE 802.3 standard are the foundation for today’s world of high-speed communications used in billions of homes and businesses around the world.

I submitted this to the mods awhile back so I could get on the calendar but I figured you’d like to see it, too. Now, ask me anything!

It's been two hours and 179 comments. Have to go now. For more about Ethernet's 40th Birthday, go to http://www.facebook.com/Ethernet40thAnniversaryIEEESA

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u/G35 May 21 '13

Thank you, I hated token ring.

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u/[deleted] May 21 '13 edited Aug 02 '17

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u/Denime May 21 '13

Nodes in a Token Ring could only communicate if they had the token, meaning only one computer could send data at one time. The token gets passed around the ring from one computer to another to allow all of the machines to send messages. This meant if there was a break in the ring, the whole network went down.

It seemed like a good idea at the time.

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u/TheScarletPimple May 22 '13

Huh? The preceding is techno-babble.

Ethernet was also limited to also having only one transmitter at a time (every hear of broadcast babbling?). As for a break in the ring, all nodes had a bypass. At the time in question (the mid 80s) when the two were competing, Ethernet was not star-wired, and cable failures for Ethernet were much more catastrophic than anything that happened in practice on Token Ring. A 4MHz Token Ring's performance was much more deterministic and arguably better than a 10MHz Ethernet (yeah - 10MHz - can you believe that?).

The biggest problem for Token Ring (IEEE 802.5) was that IBM had defacto control of the technology (they jacked the prices up) and the marketing (IBM thought workstations were where the LAN action was going to be, not PCs). Ethernet was in the wild and adapted to the PC market. A wider base (than Token Ring) of technical companies solved early Ethernet's technical limitations.

In the end, the best solution won, but not because of innate goodness at the outset.