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30 Years of Ethernet
Babylon Rocker writes "An interview with one of the inventors of Ethernet." Metcalfe talks about the history of Ethernet as well as what he's been up to for the last couple years. (Not surprisingly, he's now a VC ;)
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Metcalfe has a habit of saying stupid things, I wonder why people keep listening to him. One great invention thirty years ago, paired with a huge ego, does not an oracle make.
314-15-9265
What's VC stand for?
Venture Capitalist. People and institutions invest large sums of money into the funds run by his partnership. He then decides how to invest that money in other companies - usually high tech. startups. Its risky but potentially high reward, depending on how successful the companies he invests in become.
Sailing over the event horizon
Is there an IQ ceiling on electronics retailing or what?
Yes. I've had clerks at Frys walk out of the isle that has what I was looking for and tell me he thought it was across the store.
RJ-45 wasn't used for ethernet 30 years ago. Back then it was 10base5 (for 500 meters max cable length), or thicknet. A thick cable (that I have never seen) running thorugh the ceiling, and a AUI cable running from your computer to a tranciever in the cable. AUI is that 15 pin connector (like a pc joystick connector, but a slide holds the cable on not screws or luck) on the back of many older computers. Mostly if you see it there is a 10baseT tranciever connected to it today.
Sometime latter "thinnet" came out, or 10base2 (200 meter cable), which was a much thinner cable, and much cheaper. It is still cheaper than twisted pair for small instalations. Though almost everyone is using twisted pair because it is easier and more reliable.
I don't know exactly when 10BaseT with the rj-45 connectors came onto the scene, but it started catching on in the early 90s.
If you have, you would absolutely, certainly have the initials VC engarined in your mind. These are the overlords that controls your life and owns your soul.
Especially toward the end when all of them were changing from benevolent take-all-you-want piggybanks* to bloodsucking vampires that fires off one coworkers after next with glee**.
*note1: actually, from the beginning it was more like the inverse of beggars: they often *BEGGED* you to take their money if you just had the stupidest business plan involving the word "internet" and "e-commerce."
**note2: okay, I have to admit they didn't want to see the company they have vested interest fail, but toward the end, most VCs took control of their companies directly, and had no quarrals about tossing people out like used rags.
For all the geeks out there - the whole dot-com -> dot-bomb thing taught me one big lesson: unless you make it to upper management or start out on your own (really on your own, i.e. your own capital), you are just a (disposable) pawn in this game.
My life in the land of the rising sun.
Before 1993 or so and the advent of Switched Ethernet, Ethernet would melt down under the weight of its own traffic. 40% traffic for Ethernet is an emergency situation. I've seen TR networks hum along with 80-90% utilization and the users barely know.
Token Ring has built-in QoS. It has several levels of error monitors. These are things that are kind of added by switches, but are not a fundamental part of the topology. And if you don't have a *good* switch, you don't even have that.
Of course, in the early 90's Ethernet cards were under $100 and Token Ring cards were $400. *That's* why Ethernet won. Not speed: TR was doing 16MBit when Ethernet could only do 10, and remember, I can acually *get* 16Mbit from TR, instead of 4Mbit with Ethernet. Today, with good switches, I don't miss TR too much. But before switches...
Maybe that's why many, many very large organizations were using TR even into the early '90's. Try running 300 computers on unswiched 10Mbit Ethernet (the best Ethernet had then)...
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You forgot the best part of 10base5... the vampire taps! In order to hook up to thicknet, you have to stick a vampire tap into the coax cable, and that was hooked up through the appropriate interface box to the AUI connector.
--
"Open source is good." - Steve Jobs
"Open source is evil." - Microsoft
I wonder what would be the world without Ethernet? Would Internet begin and survive just on UUCP/SLIP/PPP?
Would you rather be stuck with Token Ring?
I mean, IBM is a great innovator to be sure. But token ring, IMHO, was one of their great misses.
There's token rings and there's token rings. Saying "Token Ring" when you mean "IBM's Token Ring" is like saying "DOS" when you mean "Microsoft's Disk Operating System".
My guess is that, in the absense of the invention of Ethernet's listen/transmit/back off on collision model, we'd have bootstrapped up from Datapoint's ARCnet.
Like IBM's protocol, ARCnet is also a token ring. But unlike IBM, ARCnet's transport layer is broadcast. So it combines the self-healing characteristics of Ethernet with the delivery-time and latency guarantees of token rings.
ARCnet did have a downside - limited number of addresses on a segment. But there are ways around that. (My favorite is my own variant which I call "bumblenet", involving an aborted binary search for the next station to get the token.)
But for radio, Ethernet-like low-level protocols have a distinct advantage over token rings: They suffer less from the "hidden transmitter" issue - where some devices can hear each other and others can't.
Ethernet-like protocols get their packet through if the transmitter and receiver can hear each other and nobody else within their earshot is talking. So a pair of stations on THIS side of the hill can swap a packet at the same time a pair of stations on the OTHER side are swapping one, without explicitly negotiating about it over relays through other stations - or even knowning about stations on the other side of the hill.
Token rings can work around a hill - even if you have a sparse chain of stations where each can only hear two neighbors. But there's a lot more effort involved. They only get simple when either everybody hears everybody else or everybody talks to exactly two neighbors in a closed ring.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
No, you're kidding me, right?
I can't believe this FUD is still out there after 30 years. Contrary to popular and mis-guided belief, an Ethernet will NOT saturate itself at 37% utilization. Period. Anyone that honestly believes that should give the token ring and ATM salesdroids and spin doctors a great big pat on the back because that's exactly what it is: sales doubletalk and spin from vendors of competing technologies. For christ's sake, this myth was laid to rest in September of 1988 . This FUD relies on over-simplifications of assumptions in the theory and inadequacies in the testing procedures.
I can't believe you'd honestly bring it up. Anyone with even a marginal amount of actual networking experience knows this to be FUD. Next time think before you speak about something you know nothing about.
Actually, TCP doesn't expect 0% packet loss at all. It expects an unreliable data path.
The problem here, as you subsequently covered, is that ethernet backs off and handles its own retransmission. This screws with the TCP timers.
If you could turn off the ethernet retransmission then TCP would still work just fine.
But yes, unswitched ethernet sucked when you had many stations trying to move large amounts of data. Token ring (and ATM!) _did_ handle load better but was much more costly.
(My DEC friends commonly refer to Ethernet as "cheapernet" with a little curled tongue action.. eww.)
Boggs invented the first (of many) hardware circuit techniques to do collision detection, and other elements of transceiver design. If Dave hadn't picked up a soldering iron, we'd probably be doing DATAKIT or some other telco hack.
...-.-
Uh, UDP is a member of the TCP/IP suite of protocols (ethernet protocol number 0800). So is ICMP. ARP (number 0806), however, is not. As far as protocols _over ethernet_, see this list of assigned protocol numbers over ethernet.
Protocols within TCP/IP are assigned numbers as well. See this list of IPv4 protocol numbers for more info. TCP packets are tagged as IP protocol 6, UDP are protocol 17, ICMP are protocol 1, etc. They are all ethernet protocol 0800, however.
Clear as mud?
Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.