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Leonard Kleinrock On The Origins of Packet Switching
An Anonymous Coward writes: "From Ben Sullivan's Tech Blog (http://www.techblog.com). An email from Leonard Kleinrock on why he really was the brains behind packet switching. It's a first-hand account from Kleinrock in a blog. A neat little journalistic scoop for bloggers, and some insights for techheads on Internet history."
"I invented packet switching"
-Al Gore
A previous discussion here.
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Oregon
"I must emphasize that the totality of understanding the full picture, and not just the issue of packetization (i.e., chopping messages into small pieces) had to be developed before a convincing body of knowledge could be amassed to prove the case for data networks."
Wow. Maybe this guy would get more credit for his discoveries if he could describe them in English
That would have been interesting. Britain as the home of the Internet.
The possibilities of an alternate history are fascinating.
In any case some of it is a matter of research being done in parallel, which means that these sort of debates will take place as a matter of course.
"It is a greater offense to steal men's labor, than their clothes"
I'm rather surprised that anyone on /. is willing to seriously consider any of these claims to have "invented" packet switching.
Every other time that someone has claimed to have "invented" an obvious electronic analogue of a well-established mechanism, we've laughed; why is this any different? Packet switching has been used in the (snail) mail system for over a century.
Tarsnap: Online backups for the truly paranoid
Umm, yes, it is that clever. When you send someone a letter (one of those cool paper things with ink on 'em), you expect it to arrive on time and in one piece. This is exactly what snailmail does. The postal service picks up your letter, routes it through their distribution channels, and delivers it to the recipient's mailbox. Now what if your company wishes to send out an enormous box containing for example a new big screen TV to some customer? You probably won't use regular mail, but have a heavier-duty delivery service handle it at a higher price because the postman would break his back lugging your box across the city. But what if there were no alternative? Man, that postman would be SLOW! Same goes for electronic bandwidth. If you'd send a single small e-mail out as a single entity (packet if you will), the chances of it arriving properly at the recipient's inbox are pretty good. This is because the tiny little email doesn't pull a lot of bandwidth and will relatively easily slip through more or less congested lines. Sending out the 2-hour video of your wedding as a single packet across a routed network is bound to give problems. Somewhere along the line the network gets congested because your huge video can't go throught he same pipe together with the next guy's MP3 collection. Result: digital roadblock and there is no such thing as UPS on the internet to deliver big packets. The smart bit on packet switching in analogy to snail mail (considering the fact that we're talking 1962 here) is this: you'd never chop that big screen TV into little pieces so a small army of postmen could swiftly deliver it to your customer and reassemble it on the spot. It must have required a pretty brilliant leap of thought to actually do this for data. Intuitively you'd think the risk of data corruption would be too great with this disassembly- reassembly-step. Luckily we're dealing with computers here, not humans, so packet switching actually did turn out a big success. PS. I know my analogy here is flawed, but hey, you get the point, right? ;-)
Learn from the mistakes of others. There isn't enough time to make them all yourself.
Hogwash to the lot of them.... The ideas they call packet switching were clearly being used by the Romans, the only difference was the transport involved people and horses not electrical signals but the transport if totally irrelevant to all the concepts they claim are packet switching. Odds are good it was used well before the Romans.
That is what Metcafe says.
How do you figure that? If it was used in the snail mail system it would mean writing one word on a sheet of paper placing that in an envelope, numbering the letter, mialing it, then repeating the process until the letter is complete. And I don't know of anybody who sends mail this way.
[Please type your sig here.]
Uh, is this even a response to this topic? Vague language and links to the home pages of science and tech-related sites? What, that's really "+3 informative."
Does this make me a troll? I've never been one yet.
Whichever idiot moderated it up deserves eternal ridicule.
Do IP packets only contain a single byte payload?
I've known a number of people to send two postcards because what they want to write doesn't fit on one; and they helpfully write "continued on next postcard", exactly the way that IP fragments do. And, somewhat rarer but an even closer analogue, when there has been a weight limit on lettermail, people have sent (for example) the first five pages of a long letter in one envelope, and the last three pages in a second envelope.
And then there's all the furniture which is shipped in parts for the recipient to assemble...
Tarsnap: Online backups for the truly paranoid
This is an excellent point. Packet switching really is an obvious idea, it is just the postal system done electronically. Watching these computer scientists squabble over these crumbs of creativity is embarrasing.
He has his very own webpage with information about the early days of the internet as well as his accomplishments.
IIRC, Ethernet was based on the "aloha" radio network in Hawaii, but there was packet switching long before there was Ethernet.
Whoever owns the patent, wins. Even that guy who said "Let's Roll"'s family lost their right to the phrase b/c someone quickly patented it.
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Let me give you the lowdown
From avi freedman's homepage: the Freedman doc - info on multihoming and BGP.
BR~z
sig?
For the common folk who no longer read the finely honed tribal rhetoric of bickering academicians this isn't about objective reporting so much as it's about jockeying for position in the ivory tower world of publish or perish.
heuristic algorithm seeks stochastic relationship
Al Gore thinks he invented the Internet.
Donald Davies is largely acknowledged for developing Packet Switching (and even coining that very phrase) at the National Physical Laboratory in the UK, however he was not American so he's largely ignored.
Packet switching refers to protocols in which messages are divided into packets before they are sent. Each packet is then transmitted individually and can even follow different routes to its destination. Once all the packets forming a message arrive at the destination, they are recompiled into the original message.
Most modern Wide Area Network (WAN) protocols, including TCP/IP, X.25, and Frame Relay, are based on packet-switching technologies. In contrast, normal telephone service is based on a circuit-switching technology, in which a dedicated line is allocated for transmission between two parties. Circuit-switching is ideal when data must be transmitted quickly and must arrive in the same order in which it's sent. This is the case with most real-time data, such as live audio and video. Packet switching is more efficient and robust for data that can withstand some delays in transmission, such as e-mail messages and Web pages.
A new technology, ATM, attempts to combine the best of both worlds -- the guaranteed delivery of circuit-switched networks and the robustness and efficiency of packet-switching networks.
...courtesy of Webopedia
Bill Gates, of course. Just ask him.
Treatment, not tyranny. End the drug war and free our American POWs.
See my user info for links.
..please post at least up-to-date and correct information.
Bbbbrrrr, calling ATM "a new technology".
The big breakthrough needed for the ARPANET was the militarized DDP-516 minicomputer, which was the first computer you could just ship someplace and expect it to work when turned on.
Packet switching is great, but it turns out that
the IP mechanism of IP packet fragmentation and
reassembly was a big mistake. In other words, you
don't want to break up packets. The original idea was that the MTU (minimum transmission unit) was
unknown, so that you should be able to have
routers which break a single IP packet into smaller fragments and have someone reassemble them elsewhere in the network. It added loads of hair and performance penalties, and really
broke the whole "end to end" model. Here in the future, I believe that people now think you can use end-to-end MTU discovery, and just keep notching the packet size down until you get reliable transmission. Anyone know if IP packet fragmentation is still part of IPV6?
Kleinrock is claiming too much credit.
Yes, his work on queueing theory is important, at least to people concerned with math and network analytics. And if anybody gives a damn about analyzing the performance of a packet-switched network mathematically, then it'll fall back onto Kleinrock's work.
But what passes for packet switching nowadays -- "The Internet" -- is most certainly not the result of careful analysis! It works by brute force. It's inefficient. It is badly monitored and mostly unmetered. So Kleinrock's analysis, which might be useful, is ignored.
Anybody with half a sense of the math wouldn't dare try to cram constant-rate streaming traffic, like telephony or broadcasting, onto the IP Internet. It's inefficient as hell. Economy of scale is what makes it seem to work, compared to economy of specialization (what ATM would excel at). But that's the Internet's current ruling ethos -- if it seems to work, do it, even to excess.
The original inventors -- Davies, Baran, and the BBN crew -- were not doing mathematical optimization. They were hacking (in the good sense) something together and observing what worked. Kleinrock is like a guy who invents a great network management system that never gets turned on, but who still claims credit for the network that his system might have been able to manage.
And puh-LEEZ, don't give Vint any of the credit. He's made a great living as the Chauncy Gardiner of the Internet.
For Baran's point of view, see this interview at Wired.
Just because someone says, "Hey, wouldn't it be cool if someone built a machine that flies" doesn't mean he invented the airplane. Even if they add details like "using a motor to force air over a convex airfoil" and "steering and stabilization by means of a vertical rudder."
You could even have detailed diagrams and equations for weight/displacement, etc. But the trick is in details like figuring out how to make the engine powerful enough achieve lift off but light enough to achieve lift off.
w(t) = ì(1 - ó) exp(-1(ì - ó)t) )
So he invented l33t speak too?
It wouldn't have been much of a stretch for a railroad designer.
Multiple routes, switches, hubs, semaphore signals. fragmenting a large train to fit between highway crossings or to go up a hill...
Multi-volume set, sent a volume at a time.
Multi-chapter book, sent a chapter at a time.
Newspaper serials, sent a column at a time.
I'm sure somebody has sent a longer missive, written on the back of postcards.
Seriously, it's typical for English to remove significant parts of words provided that the pronounciation doesn't change much. Also it's typical not to consider whether the new word is similar to already existing words. English speakers are very simple-minded in this regard.
If somebody, say, in Poland came to the market with a product called "Hot Dogs" (in Polish), they would go out of business immediately. And nobody would give a respectable site a name so closely reminding "bloated log".
absolutely. Even more so would be the way that containers are transported around the world by land and sea. Have you ever been to a modern container port? It's mind-bending.
That was classic intercourse!
The reason why mathematicians don't like computer work ?? Because a lot of the "inventions" cannot be attributed to a sole genius. And so in the field of computers there isn't enough space for the hyperspace-filling egos that you find in mathematics and physics.
The fact is, NOBODY, NOT EVEN KLEINROCK, DAVIES, AND BAREN, IN SUM OR SEPARATELY, INVENTED PACKET SWITCHING. You see, the idea did not work for almost 25 years after it was "supposedly" invented by Kleinrock et. al. It wasn't until Van Jacobsen and Karels applied optimal queuing theory and tight feedback control to exponential backoff and "slow start" to TCP feedback congestion control that packet switching was worth a damn.
I was a user of the Arpanet from 1980-1984, and the dang thing almost never worked. It would take a whole minute just to open a pair of TCP connections in order to download a single RFC. The Arpanet was badly, badly broken. Kleinrock was not responsible for making the Internet scale. What Kleinrock invented was a broke piece of crud in 1985, 1986, etc.
Do we attribute the invention of the computer to Bardeen, Brattain, and Shockley (hint : given in order of true technical contribution) because these guys invented the transistor ?? No, those guys only invented a "piece" of the modern computer - it was up to others to finish the puzzle. And it's similarly unfair to try to attribute the invention of packet switching to any ONE person, since it took 25 years to get all of the bugs out.
Don't fixate on ARPANet and TCP/IP as if they are the only form of packet switching -- it may not have worked well in the early 80s, but I can rememeber using BT's Packet SwitchStream X.25 network in 1983 -- and it worked just fine. That was certainly Mr Davies' doing.
(Be warned - this post is offtopic.)
;)
Your sig says "There is one thing humans can never do: be descendant from apes."
Computers descended from humans, and humans descended from apes. Therefore computers descended from apes.
"Destroy science and religion. Science would re-emerge exactly the same; but not religion." - Penn Jillette, paraphrased