The origins of the Internet

Paul Baran was born in 1926 in a house in a corner of Poland that had been claimed by three different nations during his parents' tenure and was brought to America by his family at the age of 2.

Baran resolved to design a communications system that could survive a nuclear attack and save the second-strike deterrent.
He took inspiration from another idea of MIT's McCullough-a parallel computer system with adaptive redundancy.
Like the human brain, such a system could reconfigure itself to work even after portions were destroyed. But using the noise-prone analog circuits of the time, it was impossible to build the necessary switches. Baran concluded that all the traffic would have to be digital.
Moreover, the digital traffic would have to be broken into short message blocks now called "packets," each containing its own routing information, like a DNA molecule, and able to replicate itself correctly whenever a transmission error occurred.
With many additions and permutations, his original design is today termed the Internet, and it is shaping the emerging history of the 21st century.

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.
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. 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.

WASTED FOREVER...LIKE WATER OVER A DAM

Liberally taken by Inventing the Internet Again - George Gilder Essay