Evolution of the Internet

The Internet was the result of some visionary thinking by people in the early 1960s that saw great potential value in allowing computers to share information on research and development in scientific and military fields. The Internet has revolutionized the computer and communications world like nothing before. What is the internet? A large number of people, world-wide, who wish to communicate and share information spontaneously in a variety of ways. A large number of computers, with appropriate applications software, available to the above people. The Internet is not a computer network - It is a network of networks. Why was the internet researched? The Soviet Union launched Sputnik, the first artificial earth satellite. In response, the United States forms the Advanced Research Projects Agency (ARPA) within the Department of Defense (DoD) to establish US lead in science and technology applicable to the military. In short, if the Soviet Union launched a nuclear attack, it was imperative that the network remain intact to facilitate communication.

This network had four main aspect in which the government cared most about; security, priority schemes, hardware and cost. This network was to be well secured from a nuclear attack so that research companies and combat post could still be linked together and still have communications between them. This research evolved right out of control from a small United States government research into a mass communication breakthrough.

J.C.R. Licklider of MIT, first proposed a global network of computers in 1962, and moved over to the Defense Advanced Research Projects Agency (DARPA) in late 1962 to head the work to develop it. The Defense Advanced Research Projects Agency commissioned development of a network over which its research centres might communicate. Its chief concern was this network's capability to withstand a nuclear attack. In short, if the Soviet Union launched a nuclear attack, it was imperative that the network remain intact to facilitate communication. The design of this network had several other requisites, the most important of which was this: It had to operate independently of any centralized control. Thus, if 1 machine was destroyed (or 10, or 100), the network would remain impervious. A government agency was commissioned by the United States Air Force to do a study on how it could maintain its command and control over its missiles and bombers, after a nuclear attack. This was to be a military research network that could survive a nuclear strike, decentralized so that if any locations (cities) in the United States were attacked, the military could still have control of nuclear arms for a counter-attack on whoever attacks them but mainly for the Soviet Union.

The roots of today's Internet come from the Advanced Research Projects Agency (ARPA). Instead of performing its own research, ARPA (a branch of the Department of Defense), which became DARPA in 1972, regularly funded research projects related to technological development or military problems. The prototype for this system emerged quickly, based in part on research done in 1962 and 1963. That prototype was called ARPANET. ARPANET reportedly worked well, but was subject to periodic system crashes; the entire network consisted of just four computers linked together from different sites to conduct research in wide-area networking. Furthermore, long-term expansion of that network proved costly. A search was initiated for a more reliable set of protocols; that search ended in the mid-1970s with the development of TCP/IP. This research was funded by the people in charge of warfare and technologies from the pentagon.

How Does TCP/IP Work? TCP/IP (Transmission Control Protocol/Internet Protocol) operates through the use of a protocol stack. This stack is the sum total of all protocols necessary to complete a single transfer of data between two machines. (It is also the path that data takes to get out of one machine and into another.) The stack is broken into layers. After data has passed through the process, it travels to its destination on another machine or network. There, the process is executed in reverse (the data first meets the physical layer and subsequently travels its way up the stack). Throughout this process, a complex system of error checking is employed both on the originating and destination machine. Each layer of the stack can send data to and receive data from its adjoining layer. Each layer is also associated with multiple protocols. At each tier of the stack, these protocols are hard at work, providing the user with various services. Today, TCP/IP is used for many purposes, not just the Internet. For example, intranets are often built using TCP/IP. In such environments, TCP/IP can offer significant advantages over other networking protocols. One such advantage is that TCP/IP works on a wide variety of hardware and operating systems. Thus, one can quickly and easily create a heterogeneous network using TCP/IP.

On January 2, 1969, designers began working on an experiment to determine whether computers at different universities could communicate with each other without a central system. The corporation Bolt, Baranek and Newman had been awarded the contract to develop the Interface Message Processor (IMP), the basis of the new communications system. IMPs were small machines which were part of each host and were dedicated to forming the network between computers. IMPs would use a technology called packet-switching, which split large sections of data into small parts called packets, each labelled with its destination address. Packets could be sent in any order and through different routes which all led to the same destination. Upon arrival at the destination computer, the packets could be reassembled. ARPANET was brought online in 1969 under the contract led by the Advanced Research Projects Agency which initially connected four major computers at universities in the south-western US (UCLA, Stanford Research Institute, UCSB, and the University of Utah). By June 1970, MIT, Harvard, BBN, and Systems Development Corp (SDC) in Santa Monica, Cal. were added. By January 1971, Stanford, MIT's Lincoln Labs, Carnegie-Mellon, and Case-Western Reserve U were added. In months to come, NASA/Ames, Mitre, Burroughs, RAND, and the U of Illinois plugged in.

E-mail was adapted for ARPANET by Ray Tomlinson of BBN in 1972. He picked the �@’ symbol from the available symbols on his teletype to link the username and address. The telnet protocol, enabling logging on to a remote computer, was published as a Request for Comments (RFC) in 1972. RFC's are a means of sharing developmental work throughout community. The ftp protocol, enabling file transfers between Internet sites, was published as an RFC in 1973, and from then on RFC's were available electronically to anyone who had

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