He created the Internet's address system, and administered it for 30 years as director of the Internet Assigned Numbers Authority (IANA). He was also a director at the Information Sciences Institute (ISI), a division of the University of Southern California (USC) that conducts advanced research in the areas of computers and communications.
In recent months, Postel had been a key figure in the Internet Corporation for Assigned Names and Numbers (ICANN), the nine-member non-profit group that will be responsible for dispensing the five most popular domain names - .com, .org, .net, .gov and .edu. He is credited with being one of the chief architects of a new plan which calls for a host of non-governmental organisations to manage future Internet growth.
Postel also served as the editor of "RFC", the "Requests For Comments", a collection of more than 2,500 technical papers that, while officially non-binding, effectively encode the technologies, rules and policies for operating the Internet.
As a graduate student at UCLA in 1969, Postel helped install the first switch on the Arpanet, an event that is widely regarded as the birth of the Internet. Building on work by theorists like Donald Watts Davies and Paul Baran, Postel worked closely with a small group of computer scientists including Bob Taylor, Larry Roberts and Vint Cerf. Together, they developed the principles for a robust method of connecting computers, called a "distributed network", that could grow without the need for a gigantic, centralised bureaucracy.
Postel and his peers foresaw the value of connecting computers long before the dawn of personal computers, e-mail and Web pages. Like Postel, many were harried academics who worked to develop network technologies that would be easy to set up and maintain and that could tolerate the programming faults and equipment failures called "bugs" (after the dead moth that actually short-circuited an early MIT machine) that were common among the era's exotic mainframe computers.
Their concept was to break information up into small chunks, or packets, each of which carries an address. By following a set of common rules, each packet could be relayed from computer to computer, effectively finding its own way from sender to receiver where it would be correctly reassembled in the correct sequence. The receiver could ask for scrambled or missing packets to be re-sent. An essential component of this scheme was a foolproof method for uniquely identifying each computer on the network.
Postel is best known for helping to invent and operate the Internet's address system and the Domain Name System which maps more human-friendly World Wide Web (like www. independent.co.uk) and other addresses to the arcane numeric addresses required by computers. His work made it easy for users to add computers to the Internet at will, which contributed greatly to the Internet's rapid growth. By helping to invent the global network, and making it accessible to millions of people, his work stands with the efforts of communications pioneers like Edison and Marconi.
Born in Altadena, California in 1943, Postel grew up in the Los Angeles suburbs of Glendale and Sherman Oaks, attending Van Nuys High School, where he was reported to be an average student. Becoming interested in computers while at a community college, he transferred to UCLA to pursue a degree in engineering, in an era before degrees in computer science were offered. He eventually earned a Doctorate in Computer Science from UCLA in 1974. It was at UCLA that he was involved in the beginnings of the Arpanet and development of the Network Measurement Center, and he began working at USC's Information Sciences Institute in 1977.
Postel was a quiet, publicity-shy individual who favoured sandals and casual clothing under his long hair and full beard. A famous 1994 photograph, taken on the occasion of the 25th anniversary of the founding of the Arpanet, shows Postel characteristically standing unassumingly at the back of the group. But colleagues say Postel's quiet demeanour and casual appearance belied a brilliant technical ability and a determination to create a soundly engineered global network.
He was highly influential in circles that helped set policies for the burgeoning Internet, and was known as an authoritative figure who could quickly settle the heated technical debates that often raged as the Internet grew. One sign of Postel's influence was a widely publicised incident earlier this year when he single-handedly re-routed the Internet's directories to alternate locations, as an experiment to prove the network's reliability.
Shortly before his death, Postel delivered to William Daley, the US Secretary of Commerce, a proposal to transfer control of the Internet from US government- funded organisations to an international non-profit corporation. "This organisation will be unique in the world - a non-governmental organisation with significant responsibilities for administering what is becoming an important global resource," wrote Postel. While his death comes at a critical time, few observers foresee difficulty. "His ideals and guidance brought us far down the road. He left us in good shape," said Joe Sims, a Washington attorney who drafted the ICANN proposal with Postel.
A memorial Web site (http://www. isoc.org/postel/condolences.shtml) has quickly filled with dozens of testimonials from many of the world's leading technologists, and Web sites around the world have placed a black banner on their pages to commemorate his passing.
Jonathan Bruce Postel, computer scientist: born Altadena, California 6 August 1943; died Los Angeles, California 16 October 1998.