The Inexorable Logic of Digital Communication
Baran, though, is not satisfied with his creation. Contemplating its vulnerability to terrorism and other attack, he feels pangs of fear that echo his alarm of 40 years before. As more and more of the critical systems of advanced industrial society migrate to the Net, they become susceptible to new forms of sabotage, espionage, hacking, and other mischief. Air traffic controls, train switches, banking transfers, commercial transactions, police investigations, personal information, defense plans, power line controllers, and myriad other crucial functions all can fall victim to cybernecine attack. If the Internet is to fulfill its promise as a new central nervous system for the global economy, its security and reliability problems will have to be addressed.
"Paul Baran is presently Chairman of the Board of Com21, Inc. He is generally blamed for creating the concept of what is now called packet switching and detailing its unusual properties in a series of RAND Memoranda in the early 1960s. He also designed and built the first doorway gun detector, and later recommended its use by the FAA to reduce hijackings. While at RAND, he was the first computer scientist to testify before Congress on the coming issue of computer privacy." From http://www.acm.org (external link)
Seventy-one years old, still with his Ph.D. economist wife Evelyn (their son David is director of information technology at Twentieth Century Fox Home Entertainment), Baran remains in the crow's nest, buffeted by inklings and insights of historic threats and opportunities. In a sense, Baran's current projects merely fulfill the far-reaching logic of his original concept, elaborated at RAND between 1960 and 1962 and published under the title "On Distributed Communications" in 11 compendious volumes in 1964: a survivable "network of unmanned digital switches implementing a self-learning policy at each node, without need for a central and possibly vulnerable control point, so that overall traffic is effectively routed in a changing environment."
To fulfill this scheme, Baran specified all the critical functions of the Internet: packets with headers for addresses and fields for error detection and packet ordering. He described in detail the autonomous adaptive nodes found in Arpanet IMPs (interface message processors) designed by Bolt, Beranek & Newman (BBN).
Baran also included features only recently and selectively introduced, such as encryption, prioritization, quality of service, and roaming ("provisions to allow each user to 'carry his telephone number' with him"). He described a web of peer nodes each connected to three or more other nodes, and he offered the first of the distributed routing algorithms that have multiplied over time.
Unique to his vision was its grasp of the economics of a network that could handle "the expected exponential growth in the transmission of digital data." Declaring that "it would be possible to build extremely reliable communications networks out of low-cost unreliable links, even links so unreliable as to be unusable in present-type networks," he estimated that the price of the system would be some $60 million per year. That was some 20 to 30 times less than what was being paid by the Department of Defense for their leased communications systems without any of these features. It was two orders of magnitude cheaper than new analog national systems being proposed at the time by each of the three military services.
Thus Baran not only conceived the essential technical features of the Internet, he also prophesied the cliff of costs over which digital technology would take the networking industry. By imagining the compounding effects of Moore's law three years before Moore's own famous prophecy, Baran stressed the key economic drivers that impelled the prevalence of the Web as the universal Net.
The system of communications that Baran attacked in the early 1960s at RAND was the imperial establishment of AT&T. As Baran explains, "While AT&T did have digital transmission under examination, it was in the context of fitting directly into the plant by replacing existing units on a one-for-one basis. A digital repeater unit would replace an analog loading coil. A digital multiplexer would replace an analog channel bank-always a one-for-one conceptual replacement, never a drastic change of basic architecture. I think that AT&T's views on digital networks were most honestly summarized by AT&T's Joern Ostermann after an exasperating session with me: 'First, it can't possibly work, and if it did, damned if we are going to allow the creation of a competitor to ourselves.'"
In 1972 the company sealed its fate by turning down an opportunity to buy the entire Arpanet. As Larry Roberts explained in {Where Wizards Stay Up Late}, "They finally concluded that the packet technology was incompatible with the AT&T network." So it was and so it still is. The existing phone system remains the chief obstacle to the final triumph of the Net. But the logic of digital communications is inexorable. It will displace all the existing establishments of television and telephony.