Defense Media Network

A DARPA Perspective on the Development of the Internet

The history of the internet is inextricably connected with DARPA and the development of new networking and information-sharing technologies. From its humble beginnings as a collection of connected research facilities to today’s global (and extra-global) network of billions of devices, a core theme of the internet’s evolution has been and continues to be the cutting-edge research conducted under DARPA’s auspices. When internet pioneer J.C.R. Licklider described, with intentional grandiloquence, his vision of an “Intergalactic Computer Network” in 1963, he still might not have imagined just how extensively the network whose seeds he planted would grow in the terrestrial realm.

In its scope and ubiquity, the internet has transformed life on a civilization-wide scale. Smartphones and other mobile devices connect bankers in Manhattan and rice farmers in India to a vast sea of information. Using predictive tools that mine this information has allowed child welfare agencies to flag high-risk cases, enabled health care providers to determine which patients are at risk for various conditions and diseases, and helped financial institutions to identify fraud and identity theft, among other benefits. But there are challenges in this new planetary data environment: The same networks of computers and databases and systems and infrastructure that afford society previously unimagined benefits also have been bringing with them new vulnerabilities for violations of privacy, cybercrime, and cyber warfare.

To get a sense of how the networked present came to be as it is now, and to imagine the potential future of an internet driven by artificial intelligence, virtual/augmented reality, and the Internet of Things (IoT), a visit to the past is a must.

first ARPANET packet router DARPA web

The Interface Message Processor (MIP) was the first packet router for the ARPANET. The first ARPANET transmission was between UCLA and Stanford Research Institute (SRI) on Oct. 29, 1969. Steve Jurvetson photo via Wikimedia Commons

 

In the Beginning

The roots of the modern internet lie in the groundbreaking work DARPA began in the 1960s (when the Agency was known as the Advanced Research Projects Agency, or ARPA) to create what became the ARPANET. In its earliest form, ARPANET began with four computer nodes, and the first computer-to-computer signal on this nascent network was sent between UCLA and the Stanford Research Institute on Oct. 29, 1969. “To understand how the ARPANET got started, it’s important to realize that at a time when there were very, very few computers in the world, a few visionaries started seeing the idea that eventually [computers] would all want to talk to each other,” said James Hendler, Director of the Rensselaer Institute for Data Exploration and Applications, and who served as chief scientist of DARPA’s former Information Systems Office.

From its humble beginnings as a collection of connected research facilities to today’s global (and extra-global) network of billions of devices, a core theme of the internet’s evolution has been and continues to be the cutting-edge research conducted under DARPA’s auspices.

Secure communications and information-sharing between geographically dispersed research facilities was one of ARPANET’s original goals. As more computers became involved in this early computer network, however, engineering problems arose. A key issue was maintaining communications, because if ARPANET behaved like a traditional circuit-based telephone system, failure of a single node could take the entire network down.

What was needed was a means to get messages to their destination in a way that did not require the presence of any single node. This is where the concept of packet switching originated. By moving bits of data that dynamically worked their way through a network to the destination and reassembled themselves there, the problem of data loss if one or more nodes went down could be avoided.

A common communications protocol between computers was also necessary, because the computers involved “were anything but compatible,” noted Vint Cerf, Vice President and Chief Internet Evangelist (this title is on his business card) for Google. Building a protocol and the software that would allow different computers to communicate and “internetwork” with each other was a significant challenge.

ARPANET was established in the last months of the 1960s, but the first major demonstration of its networking capabilities took place in Washington D.C., in 1972. At this time, the Department of Defense (DOD) became interested in using computers for command and control. Unlike ARPANET, which used dedicated phone lines to connect computer facilities together, the military wanted a mobile network to link tanks, planes, ships, and other assets together, which required the use of radio and satellite systems.

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