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The Advanced Research Projects Agency Network (ARPANET) was an early packet switching network and the first network to implement the protocol suite TCP/IP. Both technologies became the technical foundation of the Internet. ARPANET was initially funded by the Advanced Research Projects Agency (ARPA) of the United States Department of Defense.〔L.A Lievrouw - (Handbook of New Media: Student Edition (p.253) ) (edited by L.A Lievrouw, S.M. Livingstone), published by SAGE 2006 (abridged, reprint, revised), 475 pages, ISBN 1412918731 (2015-08-15 )〕〔K.G. Coffman & A.M. Odlyzco - (Optical Fiber Telecommunications IV-B: Systems and Impairments ) published by Academic Press 22 May 2002, 1022 pages, ''Optics and Photonics'', ISBN 0080513190, (edited by I. Kaminow & T. Li) (2015-08-15 )〕 Packet switching was based on concepts and designs by Americans Leonard Kleinrock and Paul Baran, British scientist Donald Davies〔(【引用サイトリンク】title=Donald Davies )〕〔(【引用サイトリンク】title=Donald Davies )〕 and Lawrence Roberts of the Lincoln Laboratory.〔(【引用サイトリンク】title=Lawrence Roberts Manages The ARPANET Program )〕 The TCP/IP communications protocols were developed for ARPANET by computer scientists Robert Kahn and Vint Cerf, and incorporated concepts by Louis Pouzin for the French CYCLADES project. ==History== Packet switching—today the dominant basis for data communications worldwide—was a new concept at the time of the conception of the ARPANET. Prior to the advent of packet switching, both voice and data communications had been based on the idea of circuit switching, as in the traditional telephone circuit, wherein each telephone call is allocated a dedicated, end to end, electronic connection between the two communicating stations. Such stations might be telephones or computers. The (temporarily) dedicated line is typically composed of many intermediary lines which are assembled into a chain that stretches all the way from the originating station to the destination station. With packet switching, a data system could use a single communication link to communicate with more than one machine by collecting data into datagrams and transmitting these as packets onto the attached network link, as soon as the link becomes idle. Thus, not only can the link be shared, much as a single post box can be used to post letters to different destinations, but each packet can be routed independently of other packets.〔("Packet Switching History" ), Living Internet, retrieved 26 August 2012〕 The earliest ideas for a computer network intended to allow general communications among computer users were formulated by computer scientist J. C. R. Licklider of Bolt, Beranek and Newman (BBN), in April 1963, in memoranda discussing the concept of the "Intergalactic Computer Network". Those ideas encompassed many of the features of the contemporary Internet. In October 1963, Licklider was appointed head of the Behavioral Sciences and Command and Control programs at the Defense Department's Advanced Research Projects Agency (ARPA). He convinced Ivan Sutherland and Bob Taylor that this network concept was very important and merited development, although Licklider left ARPA before any contracts were assigned for development.〔("J.C.R. Licklider And The Universal Network" ), Living Internet〕 Sutherland and Taylor continued their interest in creating the network, in part, to allow ARPA-sponsored researchers at various corporate and academic locales to utilize computers provided by ARPA, and, in part, to quickly distribute new software and other computer science results.〔("IPTO – Information Processing Techniques Office" ), Living Internet〕 Taylor had three computer terminals in his office, each connected to separate computers, which ARPA was funding: one for the System Development Corporation (SDC) Q-32 in Santa Monica, one for Project Genie at the University of California, Berkeley, and another for Multics at the Massachusetts Institute of Technology. Taylor recalls the circumstance: "For each of these three terminals, I had three different sets of user commands. So, if I was talking online with someone at S.D.C., and I wanted to talk to someone I knew at Berkeley, or M.I.T., about this, I had to get up from the S.D.C. terminal, go over and log into the other terminal and get in touch with them. I said, "Oh Man!", it's obvious what to do: If you have these three terminals, there ought to be one terminal that goes anywhere you want to go. That idea is the ARPANET". Meanwhile, since the early 1960s, Paul Baran at the RAND Corporation had been researching systems that could survive nuclear war〔(【引用サイトリンク】title=Paul Baran and the Origins of the Internet )〕 and presented in the United Kingdom National Physical Laboratory (NPL) the first public demonstration of packet switching on 5 August 1968. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「ARPANET」の詳細全文を読む スポンサード リンク
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