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Digital Packet-Switching
Paul Baran, computer technologist and entrepreneur, was responsible
for one of the fundamental concepts that enables today's advanced computer
networking systems: digital packet-switching. As such, he has sometimes been
referred to as one of the "grandfathers of the Internet."
Baran was born in Poland in 1926. In 1928, his family moved
to the United States and Baran spent much of his childhood helping out with
the family grocery store in Philadelphia. After high school he attended Drexel
University where he earned a degree in electrical engineering. When he
left Drexel, Baran took a job as a technician at the Eckert-Mauchly Computer
Corp. where he worked on Univac, the world's first computer. Soon after he
married and moved to Los Angeles to work at the Hughes
Aircraft Company. He began taking night classes at UCLA
and earned a master's degree in engineering in 1959.
That year, Baran left Hughes to work for the computer science
department in the mathematics division of the Rand
Institute, a nonprofit research and development organization. At that
time Rand focused on Cold War-related military problems, and Baran became
interested in the survival of communication networks in the event of a nuclear
attack. It was then that he conceived of the Internet and digital packet switching,
which allows pieces of information to be divided into small packets of data
that are addressed, sent to a specific destination, and then reassembled.
Baran had been working off the idea that the U.S. had to be
able to survive a first strike from the Soviet Union and still be able to
launch a counter-attack. Baran thought he could design a more powerful communication
network by using digital computers and by introducing redundancy. Although
he faced skepticism, Baran persevered. He studied the brain and found that
it can recover lost functions by bypassing a dysfunctional region; it does
so by not solely relying on a single set of dedicated cells for a given function.
He thought he might be able to apply this principle to the design of a communication
network.
Thus, Baran suggested a distributed network–"a communication
network which will allow several hundred major communications stations to
talk with one another after an enemy attack." This type of system would have
no centralized switch. He also had the idea to divide messages into "message
blocks" before sending them out across the network. Each block would be sent
separately and rejoined into a whole when they were received at their destination.
This concept later came to be known as packet-switching. Years later, Lawrence
Roberts was beginning work on the ARPANET at MIT
when he heard of Baran's ideas. He was designing a network both to facilitate
communications between ARPA researchers and to allow them to use remote computing
resources effectively. He decided to adopt Baran's distributed network and
packet-switching schemes, and Baran became an informal consultant for the
ARPANET project, which eventually led to what we now call the Internet.
Baran now lives in Atherton, Calif., with his wife. Baran serves
as board chairman for Com21 Inc., which he
founded in 1992. Com21 Inc. makes cable modems for high-speed, high-bandwidth
Internet access. This company is one of a number of high-tech firms started
by Baran over the years. He founded six companies in Silicon Valley including
Cable Data Associates, established in Menlo Park in 1974. Telebit, his second
company, was acquired by Cisco Systems. Equatorial
Communications was acquired by Comtel and then acquired by GTE.
Packet Technologies became StrataCom and again was subsequently acquired by
Cisco Systems. Baran also co-founded Metricom International with Paul Allen.
He is a co-founder of the Institute for the Future,
a Life Fellow of the IEEE and a Fellow of
the AAAS
[April 2001]
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