ARPAnet
ARPANET
Considered the predecessor of the Internet, ARPAnet was established by the Advanced Research Projects Agency (ARPA) in 1969 for two main reasons: to allow for the transfer of data between various institutes of research, and to answer the call of the U.S. Department of Defense for a technology that would provide messaging capabilities to the government in the event of nuclear war. Seven years earlier, ARPA hired Dr. J.C.R. Licklider to oversee how best to use emerging computer technology. Licklider is credited as being one of the first individuals to begin looking beyond the mathematical uses of computer technology and see its potential for facilitating communication between institutions and between individuals.
ARPA began formally moving forward on its plan to create a Wide Area Network (WAN) in 1967. After deciding to use Interface Message Processors (IMPs) to connect host computers via telephone lines, ARPA began looking for a contractor able to create the underlying network needed to connect the IMPs. Bolt Beranek and Newman, the Cambridge, Massachusetts-based research and development outfit that Licklider left when he began working for ARPA, successfully bid on the project. The final piece of technology needed—the protocol, or set of standards that would actually allow the host sites to communicate with one another—was developed internally by the Network Working Group.
The first three organizations connected by ARPAnet were the University of California at Los Angeles (UCLA), the Stanford Research Institute, and the University of Utah. Via ARPAnet's Network Control Protocol (NCP), users were able to access and use both computers and printers in other locations and transport files back and forth between computers. Ironically, one of the most important developments in ARPAnet technology, a more sophisticated network code known as Transmission Control Protocol/Internet Protocol (TCP/IP), also established the groundwork for what would one day supercede ARPAnet. TCP/IP replaced NCP in 1983, allowing ARPAnet to be connected with a variety of other networks that had since been launched. This group of networks evolved into what later became known simply as the Internet.
Several other key technologies emerged from various efforts to tweak ARPAnet. For example, e-mail capabilities, first introduced by Ray Tomlinson, were added to ARPAnet in 1971. Online discussion groups sprang up a short while later from address lists of e-mail users with common interests. Although the U.S. Department of Defense disbanded ARPAnet in 1990, its effects on online communications in the late 20th and early 21st centuries were immeasurable.
FURTHER READING:
Hauben, Michael. "History of ARPANET." 2001. Available from www.dei.isep.ipp.
Martin, Richard. "Present at the Creation: An Oral History of the Internet." PreText Magazine, March 1998. Available from www.pretext.com
National Museum of American History. "Birth of the Internet: ARPANET: General Overview." Washington, D.C.: Smithsonian Institution. 2001. Available from smithsonian.yahoo.com/arpanet2.html
SEE ALSO: History of the Internet and WWW
ARPANET
The impetus for the ARPANET came from a small group of workers in universities and private research laboratories in the USA, who were funded by the US Department of Defense Advanced Research Project Agency to create a data network that was capable of continuing to function even when parts of the network were destroyed. The solution proposed relied on the use of packet switching, which was implemented by small dedicated computers called interface message processors (IMPs), and used a distributed routing algorithm to manage the movement of self-contained packets of data between their source and destination.
ARPANET pioneered many of the network concepts now in current use, including the use of layered protocols. Each protocol governs the transfer of information for a range of associated applications, and delegates the control of the traffic flow to cooperating processes located either at the end-user applications, or, for the lower layers of the protocol, to processes located in the switching nodes.