Paul Baran (1926-2011)
march 29, 2011
By Tom Wheeler
During the Cold War U.S. defense planners became concerned that the central switching of the telephone network was vulnerable in the event of a Soviet attack. Because the message to launch an American counterstrike used the telephone network, an enemy first strike could easily destroy the critical switches necessary for a launch message to reach its destination. The Defense Department commissioned Rand Corporation, a California research institution, to come up with a solution.
In 1964 Baran, then a young Rand engineer, published “On Distributed Communications.” His idea was that instead of an end-to-end circuit that could be broken by destroying a switching point, the launch message should be digitized, broken into multiple pieces (“packets”), each containing digital instructions as to its destination, and routed through a hub-less network. Should an attack take out one link the network would simply reform using connections that bypassed the problem. The fishnet-like digital network of today was born.
Baran’s distributed network became the cornerstone of the doctrine of Mutually Assured Destruction (MAD) that by keeping the world on the brink of nuclear destruction successfully avoided annihilation. The ability of the U.S. command and control network to survive a preemptive strike and respond in force was so important that the U.S. government openly shared the details of the new network with the Soviet government so they could understand the folly of a first strike.
Paul Baran overturned the common knowledge about networks that had existed since hunter-gatherers had followed the paths of their prey. Networks had always been a point-to-point open pathway. The new network design was especially an anathema to those who ran traditional networks. The first-strike risk that Baran’s plan overcame was the consequence of the telephone company’s centralized architecture. Yet AT&T, the monopoly long distance provider of the time, refused the Defense Department’s request to solve that problem by building a distributed network. In the end the government built the network itself; after multiple iterations it became ARPANET and ultimately the model for the Internet.
I had the privilege of discussing the history of those days of discovery with Paul Baran many times. He would laugh as he recalled the challenge of trying to explain the distributed network concept to engineers at the telephone company. He said it was as if he was “speaking Swahili.” The engineers at the telephone company had been raised in an analog world and only thought in terms of setting up and taking down end-to-end circuits. The idea that connections could be made without maintaining a constant open circuit was beyond the scope of their imagination. The idea that messages would be sent by constantly establishing and then destroying a connection was incomprehensible. At one point in the effort to try and get AT&T to build the new network it was necessary to enlist the scientists at Bell Laboratories who were doing pioneering work in digital technology (but who understood analog) to act as interpreters so the analog engineers at AT&T could understand the concepts Baran was advancing.
One of the most endearing qualities of this giant of a man was his modesty. “The Internet is really the work of a thousand people,” he once explained. He likened the developments that followed his as like “building a cathedral.” “Over the course of several hundred years, new people come along and each lays down a block on top of the old foundations, each saying, ‘I built a cathedral.’” Paul Baran did not invent the Internet, but his discovery did enable what became the Internet. If we are to follow his cathedral metaphor, someone had to lay the cornerstone.
It was my privilege to call Paul Baran a friend. Imagine the unique honor of learning about digital networks from the man who developed the concept that made them possible. Consider the marvel of sitting with Paul when he would say, “I’ve got a new idea” (he started seven companies, five of which went public). He was a quiet man in his demeanor, but oh so loud in what he accomplished and contributed. We stand on the precipice of great new things because what Paul Baran left us.
Tom Wheeler is Managing Director of Core Capital Partners, a venture capital firm specializing in early stage companies, including next generation wireless services. For almost a dozen years prior to joining Core Capital he was the president of the Cellular Telecommunications & Internet Association.