According to this concept, all computers across the planet would be interconnected and by this, everyone could quickly access data and programs from any ‘site’. This is what actually happens today. J C R Licklider joined DARPA (Defence Advanced Research Projects Agency www.darpa.mil/) in October 1962 and was its first research head. In due course at DARPA, he convinced his successors, Ivan Sutherland, Bob Taylor, and MIT researcher Lawrence G Roberts, of the importance of this networking concept.
In late 1966, MIT researcher Lawrence G Roberts went to DARPA to develop the computer network concept and quickly put together his plan for the “ARPANET” (Advanced Research Projects Agency Network related to the US Department of Defence) publishing it in 1967. Roberts presented his paper at a conference, where, incidentally, Donald Davies and Roger Scantlebury of NPL (National Physical Laboratory) from the UK presented a paper on a packet network concept.
Earlier during his research, Leonard Kleinrock at MIT convinced Roberts of the feasibility of using packets rather than circuits to transfer data, which, by itself was a major leap forward in the area of computer networking. To prove this, Roberts, with Thomas Merrill in 1965, connected the TX-2 computer in Massachusetts to the Q-32 computer in California using an extremely low-speed dial-up telephone line creating the first (though small) wide-area computer network ever built.
This confirmed Kleinrock’s theory of the need for packet switching since the circuit-switched telephone system was insufficient for the job. This also proved another aspect, which was that time-shared computers could work well together and running programs or retrieving data could be carried out without any issues. The word “packet” was adopted from the work at NPL and the proposed line speed to be used in the ARPANET design was upgraded from 2.4 kbps to 50 kbps.
This was just the start. By August 1968, Roberts and DARPA funded community refined the overall structure and specifications for ARPANET. This led to a release of a ‘Request For Quotation’ by DARPA to manufacture packet switches called Interface Message Processors, which, was fulfilled by a firm called BBN. Bob Kahn from BBN worked on the IMP’s while Roberts worked on and optimised the network topology and economics. At the same time, Kleinrock’s team at UCLA prepared a network measurement system.
Kleinrock’s Network Measurement Center at the University of California at Los Angeles (UCLA) was selected to be the first node on the ARPANET. All this finally came together in September 1969 when BBN installed the first IMP at UCLA and the first host computer was connected.
Stanford Research Institute was selected as the second node and when SRI was connected to the ARPANET, the first host-to-host message was sent from Kleinrock’s laboratory to SRI. Two more nodes were added at UC Santa Barbara and University of Utah and at the end of 1969 four host computers were connected into the initial ARPANET, and the fledgling Internet came into existence.
Bob Kahn organised a large and successful demonstration of the ARPANET in October 1972 at the International Computer Communication Conference (ICCC) which was also the first time that this completely new networking technology was demonstrated in front of the general public. In the same year, the electronic mail or e-mail, as we know it, was introduced. Ray Tomlinson from BBN wrote a very basic e-mail ‘read and send’ software that was later developed further by Roberts. The development was driven by the need of ARPANET developers to coordinate amongst themselves but by the next decade, e-mail became the largest network application to have ever hit the internet.