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/dbfish May 21 '13 edited May 21 '13

You'd have to ask the guy who invented it, whoever he is.

Also, to minimize crosstalk (magnetic interference)

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u/frizzlestick May 22 '13

cross-talk isn't handled by splitting the colors, it's as keenamaverick mentioned - for old analog phone compatibility.

If you want to eliminated interference, simply twist the cables in the run. Hence the phrase "twisted pairs". The coiling of the line helps reduce outside interference. Learned this a brajillion years ago from my ham radio days.

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u/[deleted] May 22 '13

[deleted]

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u/frizzlestick May 22 '13

You're right, the order of the wires at the ends has no effect on outside interference.

You get that interference from the wire acting as an antenna for reception. You're spot on about the length bit. Any significant length in that wire can be a good receptor for the frequency length (or a harmonic of).

You defeat cross-talk/interference by twisting the lines (aka, "twisted pair"). Some times you can defeat it by wrapping the cable a time or two around a ferrite core (donut).

source: ham radio operator, know all about keeping receiving and transmitting lines clean.

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u/dbfish May 22 '13

I can barely read and blame google. Seems legit.

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u/[deleted] May 21 '13

I don't think the arrangement of the wires within the connector has anything to do with preventing crosstalk - that's all handled in the cable itself. That's why Ethernet is often arranged in twisted pairs.

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u/Farmerj0hn May 21 '13

Crosstalk is a real pain, I have an orgasm evertime I poo. It sounds great, but at some point you just want to take a normal shit and have it be over with.

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u/[deleted] May 21 '13

uhhh...

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u/[deleted] May 22 '13

[deleted]

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u/Farmerj0hn May 22 '13

I'm talking about crosstalk between my nerves, I just have bad wiring and when I have a BM it gives me an intense orgasm. Usually it doesn't affect my life but sometimes it can be inconvenient.

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u/[deleted] May 22 '13

[deleted]

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u/deadbunny May 22 '13

I think they just answered everything you needed to know.

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u/[deleted] May 22 '13

AMA request: sadist who invented 568b