History of the Internet

Map of Internet, February 1982
Map of Internet, February 1982

I recently watched a fascinating video (see below) that presents the history of the Internet from 1958 to present. There were several important technological events mentioned that led to the Internet of today. Below are five that I think are the most important.


In the 1958 the United States set up Defense Advanced Research Projects Agency (DARPA) response to the Sputnik launch by the Soviet Union. The mission is to prevent strategic surprise and ensure the United States stayed at the forefront of military technology. This mission required the agency to coordinate research conducted by institutions throughout the country. It supported the evolution of the ARPAnet in order to prevent duplication of research and to speed development. The ARPAnet was the foundation that modern Internet is built on.

Packet Switching

Packet Switching is an innovation important to the early ARPAnet for it made this shared networks more efficient. Packet Switching networks are designed to divide data into equally sized packets before transmitting those data over a network. These smaller packets of data allow networking hardware with limited computing resources to queue and buffer data was it’s transmitted over nodes. The ARPAnet could then effectively manage network capacity allowing it to grow into the Internet we use today.


In the early 1970’s the French developed a research packet switching network called CYCLADES. It was the first network to make hosts, rather than the network, responsible for the reliability data delivery. This greatly reduced the complexity of packet switches and proved that host-based responsibility was indeed workable. Though CYCLADES was shutdown by the French in 1981 the lessons learned were incorporated into the OSI model.


The X.25 protocol was developed by the ITU Telecommunication Standardization Sector (ITU-T) to provide access to the Internet via telephone company connections. This had the benefit of lower costs to users all over the world because they could connect using installed phone systems. It was developed before the OSI model and consists of three layers. These layers are similar though to the three lowest levels of the OSI model’s seven layers. In my opinion the most significant impact of X.25 was the ability for it to provide users in the 1980’s access to Internet without requiring costly new infrastructure.


The Transmission Control Protocol (TCP) and Internet Protocol (IP) were developed and integrated into the ARPAnet between 1973 and 1983. The US Department of Defense was the first to declare it as the standard for all military computer networking in March 1982. Its adoption exploded in 1989 when AT&T agreed to place code developed for UNIX into the public domain. Software companies such IBM and Microsoft incorporated this code into the TCP/IP stacks for operating systems into the 1990s thus standardizing the Internet based on TCP/IP.

Still interested? Check out this video for an overview the history of the Internet.

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