The History of TCPIP and the Internet

The History of TCP/IP and the Internet

While most people think TCP/IP is a single protocol, it actually refers to a suite of communication protocols: the Transmission Control Protocol (TCP) and the Internet Protocol (IP) are two of the most common protocols used in the suite, but they are by no means the whole of the TCP/IP suite. Other protocols that feature TCP/IP include the User Datagram Protocol (UDP) and the Internet Control Message Protocol (ICMP).

The ARPANET

In 1968, the United States Department of Defense (DoD) Advanced Research Projects Agency (ARPA), later called the Defense Advanced Research Projects Agency (DARPA), began researching the network technology that is now called packet switching. TCP/IP is one of the protocols that originated from this research. The intent of TCP/IP was to facilitate communication among the DoD community without using the public-switched telephone network. This network was called the ARPANET, and it is the predecessor to today's Internet. In 1978, the separate functions of TCP and IP were formalized, and in 1983, they became standard protocols for ARPANET. In 1989, the machines on the ARPANET were switched over to the NSFnet, the National Science Foundation network, a much larger and faster network than the ARPANET. This became what is known today as the Internet. Because of the history of the TCP/IP protocol suite, it is often referred to as the DoD protocol suite or the Internet protocol suite.