The Innovators: How a Group of Inventors, Hackers, Geniuses, and Geeks Created the Digital Revolutio - Isaacson Walter. Страница 65

Unable to afford college, even at tuition-free City College of New York, he worked days at an electronics firm and took night courses. The instructors at night were more practical than those during the day; instead of being taught the theory of a transistor, Kleinrock remembered his teacher telling him how heat-sensitive they were and how to adjust for the expected temperature when designing a circuit. “You’d never learn such practical things in the day session,” he recalled. “The instructors just wouldn’t know that.”⁶⁰

After graduating, he won a fellowship to do his doctorate at MIT. There he studied queuing theory, which looks at such questions as what an average wait time in a line might be depending on a variety of factors, and in his dissertation he formulated some of the underlying math that analyzed how messages would flow and bottlenecks arise in switched data networks. In addition to sharing an office with Roberts, Kleinrock was a classmate of Ivan Sutherland and went to lectures by Claude Shannon and Norbert Wiener. “It was a real hotbed of intellectual brilliance,” he recalled of MIT at the time.⁶¹

Late one night at the MIT computer lab, a tired Kleinrock was running one of the machines, a huge experimental computer known as the TX-2, and heard an unfamiliar “psssssss” sound. “I began to get very worried,” he recalled. “There was an empty slot where a piece of the machine had been removed to be repaired, and my eyes raised up and I looked at that slot and looking back were two eyes!” It was Larry Roberts, playing a prank on him.⁶²

The effervescent Kleinrock and the tightly controlled Roberts remained pals, despite (or maybe because of) their difference in personalities. They enjoyed going to Las Vegas casinos together to try to outsmart the house. Roberts came up with a card-counting scheme for blackjack, based on tracking both high and low cards, and he taught it to Kleinrock. “We got kicked out once, playing with my wife at the Hilton, when the casino managers were watching us through the ceiling and became suspicious when I bought insurance on a hand when you normally wouldn’t unless you knew there weren’t many high cards left,” Roberts recalled. Another ploy involved trying to calculate the trajectory of the ball at the roulette table using a counter made from transistors and an oscillator. It would measure the velocity of the ball and predict which side of the wheel it would end up on, allowing them to bet with more favorable odds. To gather the necessary data, Roberts had his hand wrapped in gauze to hide a recorder. The croupier, figuring something was afoot, looked at them and asked, “Would you like me to break your other arm?” He and Kleinrock decided not, and left.⁶³

In his MIT dissertation proposal, written in 1961, Kleinrock proposed exploring the mathematical basis for predicting traffic jams in a weblike network. In this and related papers, he described a store-and-forward network—“communication nets in which there is storage at each of the nodes”—but not a purely packet-switched network, in which the messages would be broken up into very small units of the exact same size. He addressed the issue of “the average delay experienced by a message as it passes through the net” and analyzed how imposing a priority structure that included breaking messages into pieces would help solve the problem. He did not, however, use the term packet nor introduce a concept that closely resembled one.⁶⁴

Kleinrock was a gregarious and eager colleague, but he was never known for emulating Licklider in being reticent about claiming credit. He would later alienate many of the other developers of the Internet by asserting that, in his PhD thesis and his paper proposing it (both written after Baran began formulating packet switching at RAND), he had “developed the basic principles of packet switching” and “the mathematical theory of packet networks, the technology underpinning the Internet.”⁶⁵ Beginning in the mid-1990s, he began an energetic campaign to be recognized “as the Father of Modern Data Networking.”⁶⁶ He claimed in a 1996 interview, “My dissertation laid out the basic principles for packet switching.”⁶⁷

This led to an outcry among many of the other Internet pioneers, who publicly attacked Kleinrock and said that his brief mention of breaking messages into smaller pieces did not come close to being a proposal for packet switching. “Kleinrock is a prevaricator,” said Bob Taylor. “His claim to have anything to do with the invention of packet switching is typical incorrigible self-promotion, which he has been guilty of from day one.”⁶⁸ (Countered Kleinrock, “Taylor is disgruntled because he never got the recognition he thought he deserved.”⁶⁹)

Donald Davies, the British researcher who coined the term packet, was a gentle and reticent researcher who never boasted of his accomplishments. People called him humble to a fault. But as he was dying, he wrote a paper to be published posthumously that attacked Kleinrock in surprisingly strong terms. “The work of Kleinrock before and up to 1964 gives him no claim to have originated packet switching,” Davies wrote after an exhaustive analysis. “The passage in his book on time-sharing queue discipline, if pursued to a conclusion, might have led him to packet switching, but it did not. . . . I can find no evidence that he understood the principles of packet switching.”⁷⁰ Alex McKenzie, an engineer who managed BBN’s network control center, would later be even more blunt: “Kleinrock claims to have introduced the idea of packetization. This is utter nonsense; there is NOTHING in the entire 1964 book that suggests, analyzes, or alludes to the idea of packetization.” He called Kleinrock’s claims “ludicrous.”⁷¹

The backlash against Kleinrock was so bitter that it became the subject of a 2001 New York Times article by Katie Hafner. In it she described how the usual collegial attitude of the Internet pioneers had been shattered by Kleinrock’s claim of priority for the concept of packet switching. Paul Baran, who did deserve to be known as the father of packet switching, came forward to say that “the Internet is really the work of a thousand people,” and he pointedly declared that most people involved did not assert claims of credit. “It’s just this one little case that seems to be an aberration,” he added, referring disparagingly to Kleinrock.⁷²

Interestingly, until the mid-1990s Kleinrock had credited others with coming up with the idea of packet switching. In a paper published in November 1978, he cited Baran and Davies as pioneers of the concept: “In the early 1960’s, Paul Baran had described some of the properties of data networks in a series of RAND Corporation papers. . . . In 1968 Donald Davies at the National Physical Laboratories in England was beginning to write about packet-switched networks.”⁷³ Likewise, in a 1979 paper describing the development of distributed networks, Kleinrock neither mentioned nor cited his own work from the early 1960s. As late as 1990 he was still declaring that Baran was the first to conceive of packet switching: “I would credit him [Baran] with the first ideas.”⁷⁴ However, when Kleinrock’s 1979 paper was reprinted in 2002, he wrote a new introduction that claimed, “I developed the underlying principles of packet switching, having published the first paper on the subject in 1961.”⁷⁵

In fairness to Kleinrock, whether or not he had claimed that his work in the early 1960s devised packet switching, he would have been (and still should be) accorded great respect as an Internet pioneer. He was indisputably an important early theorist of data flow in networks and also a valued leader in building the ARPANET. He was one of the first to calculate the effect of breaking up messages as they were passed from node to node. In addition, Roberts found his theoretical work valuable and enlisted him to be part of the implementation team for the ARPANET. Innovation is driven by people who have both good theories and the opportunity to be part of a group that can implement them.