Advanced Research Projects Agency Network

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What Does Advanced Research Projects Agency Network Mean?

The Advanced Research Projects Agency Network (ARPANET) is a predecessor to the modern Internet. It was conceptualized in the 1950s, when computer scientists needed something better than the then available but unreliable switching nodes and network links.


There were also only a limited number of large, powerful research computers, and researchers with access were separated geographically. The Advanced Research Projects Agency (ARPA) commissioned the development of an advanced and reliable way to connect these computers through a newly devised packet switching network, which was known as ARPANET.

Techopedia Explains Advanced Research Projects Agency Network

The ARPANET was a project funded by the U.S. government during the Cold War, in order to build a robust and reliable communications network. This was done by connecting various computers that could simultaneously communicate in a network that would not go down and continue running when a single node was taken out.

The initial groundwork for a computer network was laid by Joseph C. R. Licklider of Bolt Beranek and Newman (BBN). Licklider became the head of the behavioral sciences and command and control programs at ARPA in October 1963. He then convinced Ivan Sutherland and Bob Taylor to work on this concept. In his office, Bob Taylor had three computer terminals connected to the three ARPA-sponsored computers:

  • The System Development Corporation (SDC) Q-32 at Santa Monica
  • Project Genie at the University of California, Berkeley
  • Multics at the Massachusetts Institute of Technology

When Taylor needed to talk to someone at another computer, he would transfer to a different terminal for each connection. This was frustrating and led to the concept of one terminal/computer connected to a number of other terminals. This idea paved the way for the ARPANET and, eventually, the modern Internet.

Paul Baran of Rand Corporation concluded that the strongest kind of network would be a packet switched network that would use any available communication line, regardless of the status of other lines. The ARPANET originally connected four computers, as follows:

  • A Honeywell DDP 516 computer at University of California, Los Angeles
  • An SDS-940 computer at the Stanford Research Institute
  • An IBM 360/75 at University of California, Santa Barbara
  • A DEC PDP-10 at the University of Utah

Compatibility issues surfaces as more computers were connected to the network. These problems were solved in 1982 through the development of Transfer Control Protocol/Internet Protocol (TCP/IP).


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Margaret Rouse
Technology Expert
Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.