- Person
- Leonard Kleinrock
- Lived
- b. 1934
- Field
- Computer networking
- From
- American
The story
Leonard Kleinrock was born in New York City in 1934 to a Jewish family. He built a crystal radio at six from plans in a comic book, studied at night at the City College of New York while working full time, and then won a fellowship to MIT. There, in the early 1960s, he chose a subject almost no one was studying: how data could flow through networks of computers. His doctoral work, published in 1964 as Communication Nets, used the mathematics of queueing to predict delays in networks that store and forward messages, and it gave engineers tools to analyse network performance.
Kleinrock joined UCLA in 1963. When the U.S. Defense Department’s Advanced Research Projects Agency planned a computer network, he helped write its functional specification in 1968 and won a contract to run the network’s measurement centre at UCLA, which became its first node. The first Interface Message Processor, the network’s packet switch, arrived on August 30, 1969, and on September 2 data flowed between it and UCLA’s computer.
At 10:30 in the evening of October 29, 1969, in room 3420 of Boelter Hall, student programmer Charley Kline, supervised by Kleinrock, tried to log in to a computer at the Stanford Research Institute. He typed L and O, each confirmed by telephone; when he typed G, the Stanford system crashed. The first message on the network was therefore “lo”. About an hour later the full login worked. By December four sites were connected, and the network kept growing.
Kleinrock’s team, including graduate students Steve Crocker, Jon Postel and Vint Cerf, wrote the host software that let computers talk across the network, and many of his students went on to build the protocols of the internet. Room 3420 has been restored as the Kleinrock Internet Heritage Site and Archive. Kleinrock received the National Medal of Science for his work on the mathematical theory of data networks.
Why it matters
The network that began in Kleinrock’s laboratory grew into the internet, which billions of people now use to learn, work, trade and stay in touch.
About Leonard Kleinrock
New York-born computer scientist who built the mathematical theory of data networks; his UCLA lab became ARPANET’s first node and sent its first message in 1969.
Sources
- Leonard Kleinrock’s Personal History/Biography: The Birth of the Internet UCLA
- Leonard Kleinrock Internet Hall of Fame
- Leonard Kleinrock Wikipedia
Another act of tikkun olam. This is part of tikkun olam, the Jewish idea of repairing the world, and every one of us can add to it.