The foundations of today’s internet rest on Cold War-era research and development performed by the Defense Advanced Research Projects Agency and researchers associated with the Department of Defense’s ARPANET. ARPANET used a packet-switching approach pioneered by RAND’s Paul Baran, but was unable to interface with other networks being developed. To solve this problem, DARPA researchers developed the Transmission Control Protocol and the Internet Protocol, or TCP/IP. These protocols used end-to-end principles, allowing multiple “subnets” using TCP/IP to interconnect to form the internet.
The following documents provide a glimpse into the research that made the internet possible.