Internet History Series

IOTVeteran Internet History - ARPANet

ARPANet. Classified research for the good of the world

There were certainly scientists and developers researching computer science outside of Cambridge, Massachusetts and Menlo Park, California. But the organizations and schools in these areas eventually became pioneers of the ARPANet, the first network of its size and type. The story of the ARPANet is well documented by the Department of Defense, and not without conflict. A little research into the subject has turned up everything from infamous protests, sarcastic administrator memos, and even some well-versed poetry.  

What is ARPA and the ARPANet?

To many the internet is still in its infancy, we have been told in recent years that the state of communications will soon change forever. When preparing for the changing technological advancements, it’s important to look back and see where they came from. The internet as we know it did not begin in the 1990’s with the dot com boom; AOL, Compuserve, and even Microsoft had very little to do with the origins of the internet. These are owed to organizations such as Bernak, Brown, and Root (BBN, later Raytheon), Stanford, MIT and of course the patriarchal figure of the entire program: the Department of Defense

As computers were being developed, the need to connect them together became apparent. In the early days of the ARPANet, four terminals on the west coast were connected together to form a network. The researchers behind this project knew that connection of computers was imminent and that the challenges in doing so would be massive. It became obvious that new technologies would have to be developed to allow for the sharing of resources between these new supercomputers, as many departments and organizations were clamoring for their use. 

Who Was Behind the ARPANet

Researchers such as Leonard Kleinroch (UCLA), Douglas Engelbart (SRI), and J.C.R. Licklider (BBN)  knew that the coming network of computers would need to be more than just a stretched out series of wires connecting machines together. Sharing resources, distant connections, management of traffic, as well as the physical limitations of extremely simple computing systems all posed challenges they must overcome. 

The only problem for these researchers is that the Department of Defense was eagerly pursuing the use of this technology to help win the Cold War.

In 1969 students at Stanford began protesting the use of university resources for classified DoD research. The main target of the April 3rd Movement (A3M) was the Applied Electronics Lab. After university faculty shut down classified research in the lab, the protestors turned their attention to SRI. 

SRI, Stanford Research Institute, is a federally funded innovation hub, that has been responsible for many of the advancements in  modern life. SRI was and is funded by the Department of Defense under the Advanced Research Projects Agency (ARPA, now DARPA, Defense Advanced…). SRI is not officially under the control of the Stanford faculty, although it is heavily affiliated, SRI International continued to take DoD money to fund their research. 

Students protest against Stanford receiving DoD funding via SRI during the April 3 movement.

MIT was also experiencing backlash for pursuing the ARPANet and receiving DoD money. Students at MIT felt the same way about the situation in Vietnam as they did in California. In order to avoid controversy MIT President James Killain did not allow any classified research on campus, and established the Lincoln Laboratory off-site in order to obscure the connection between the two.

The Lincoln Laboratory had been operating under the umbrella of the DoD for many years, starting with radiation research during WWII. It was only once the sentiment for war changed during the Vietnam years, that MIT accepting DoD money became an issue.  In 1969 the U.S. Air Force granted permission for the Lincoln Lab to pursue non-defense related pursuits, but these projects did not begin until 1971.

Regardless of the feelings of the student union, Department of Defense funding occurred, and Lawrence Roberts of ARPA was appointed as project manager. If not for Mr. Roberts, who claims to have cut the most checks in support of ARPANet ( a valiant effort for sure), the collaboration between the nations’ top think tanks would have most likely not been possible. 

So began the work on the ARPANet. Local carriers provided backbone connections, and the first four nodes came online. In September of 1969, Leonard Kelinrock’s Network Measurement Center (NMC) at UCLA, Douglas Englebart of SRI operated the Network Information Center (NIC), University of Utah graphics department, and the UCSB Culler-Fried Interactive Mathematics Center all became the first four nodes on the ARPANet.

This map shows the first four nodes connected to the ARPANet in December 1969

Personal communications were banned on the ARPANet, as traffic was slow and expensive. In the early iterations of the ARPANet, the connections and computing power were used solely to attempt to improve packet switching network technology in general. Some of the focuses were sharing of files and resources, interconnecting different hardware, and a standard programming language.


Most of the innovation in the early days was associated with the Interface Message Processors (IMPS). These precursors to routers were manufactured by BBN and were stand alone machines that required a large rack. The development of the TIP, or Terminal Interface Processor (TIP) in 1971 made it possible for ARPANet nodes to be installed in many locations. TIPs were half the price and served as both a terminal and a message processor. This means that users could execute functions on the terminal itself, rather than needing to use a separate machine. IMPs and TIPs were very important innovations in the world, as they later became known as switches and routers

BBN Manufactured Interface Message Processor
The BBN Manufactured Interface Message Processor. The predecessor to the router, allowed for connection between terminals of different types to the ARPANet.

Cross country land race:

After four computers were successfully added to the network, the cross country connection between the two U.S. coasts was constructed by way of the University of Utah. The next nodes added connected the brilliant minds of Cambridge with the wizards at Menlo Park and Los Angeles. The next sites added were the RAND Corporation, University of Illinois Urbana-Champaign, Case Western Reserve University, Carnegie Mellon University, and NASA’s Ames Research center.  In 1973 35 nodes and 14 TIPs had been installed on the ARPANet, and by 1983 there were 4000 nodes. 

The ARPANet was transferred to the Defense Communications Agency (now known as the Defense Information Systems Agency / DISA). At this time it became a tool in the national communications system, and was protected by the secrecy that comes with Department of Defense projects.

The ARPANet was eventually shut down, and transitioned into the NSFNet, it had been around for 21 years, and eventually gave way to the modern internet after the passage of the High Performance Computing Act of 1991. 

There is not a lot of information regarding the ARPANet in the 1980’s or 1990’s, due to the nature of its use. The ARPANet was the first packet-switched multi-node network, but it allowed the greatest minds in the country to connect and build a future.

Further Reading

ARPANet Completion Report. Prepared By: F. Heart, A. McKenzie, J. McQuillan, and D. Walden of Bolt, Beranek, and Newman Inc. January 4, 1978

The Birth and Development of the ARPANET . Ronda Hauben

Hobbes’ Internet Timeline. Robert H’obbes’ Zakon

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