Paul Baran was a pioneer in the development of computer networks, creating one of the core concepts of the internet: packet‑switched computer networking.

In the 1960s, Baran, one of the founding fathers of the internet as a researcher at RAND, developed the concept of packet switching as an integral part of the new technology that would become the internet. Several years before the ARPANET was created, Baran had two ideas that became very important in its development: the idea of building a distributed network, and a technique for data transmission that later came to be called packet switching.

After joining the RAND Corporation in 1959, Baran took on the task of designing a “survivable” communications system that could maintain communication between end points in the face of damage from nuclear weapons.

RAND was a think tank that focused mostly on Cold War–related military issues, and was looking for communications systems that would survive a nuclear attack. People at RAND, America’s foremost military think tank, were trying to figure out an important strategic problem: how US authorities could talk to each other in the aftermath of a nuclear attack. An article on the RAND website, Paul Baran and the Origins of the Internet, states that Baran offered a solution “to communicate in the aftermath of a nuclear attack.” It is often debated whether RAND’s view was the primary goal of the ARPANET.

Even before arriving at RAND, Baran had been thinking about the concepts of redundancy and rerouting that were put forth in the neurobiologist Warren McCulloch’s work on neural nets.

When he heard that the Air Force had asked RAND to explore survivable communications, Baran’s ideas found a perfect application. He conceived the idea for a new kind of communications network—one that wasn’t organized point‑to‑point, but instead was set up more like a fishnet. The idea was to create a decentralized computer network whereby every computer was connected to each other. In this case, even if one of the systems was hit, the others would remain unaffected. Computers in the 1960s were very large and very expensive, and this new proposed network would also solve another problem: allowing various agencies and locations the ability to use computers in other locations.

One of the key differences between communications before the internet and the way information flowed with the new standards known as Internet Protocol is the concept of packet switching.

Throughout the standard for Internet Protocol you will see the description of packet switching: “fragment and reassemble internet datagrams when necessary for transmission through small packet networks.” A message is divided into smaller parts known as packets before they are sent. Each packet is transmitted individually and can even follow different routes to its destination. Once all the packets forming a message arrive at the destination, they are recompiled into the original message. Baran’s concept of packet switching was part of his survivability work, as it allowed for a system that could route traffic around an area if there was a problem—packets would simply be routed around it.

In 1964, Paul Baran, working for RAND, wrote On Distributed Communications Networks, which described packet‑switching networks with no single outage point.

In 1969, when the US Defense Advanced Research Projects Agency (ARPA) started developing the idea of an inter‑networked set of terminals to share computing resources, the reference materials they considered included Baran and the RAND Corporation’s On Distributed Communications. While it is debated in some circles whether RAND’s view was the primary goal of the internet, Baran’s work clearly influenced the early thinking behind ARPANET.

The RAND Corporation was founded after the Second World War as a research agency for the United States armed forces by Douglas Aircraft Company. It is currently incorporated as a non‑profit organization with its main office in Santa Monica, California. The name RAND is a contraction of “Research and Development.” RAND continues to operate today as a nonprofit research and analysis institution across a broad range of subjects.

The 1960s: the internet is conceived.