Happy 30th birthday to the internet as TCP/IP reaches milestone

Tim Berners-Lee may be the celebrated British "father" of the world wide web as we know it, but a hugely important ingredient of the modern internet was switched on 30 years ago yesterday, as the US government's ARPANET started running the TCP/IP communications protocol.

The ARPANET – Advanced Research Projects Agency Network – was a US military computer communication system designed and used during the Cold War by DARPA (the US Defense Advanced Research Projects Agency).

It was also the world's first packet-switched network, which was simply an extension of the send and receive idea behind letters and telegrams.

The ARPANET's sending and receiving of data, however, had no common language.

"Each network had its own communications protocol using different conventions and formatting standards to send and receive packets, so there was no way to transmit anything between networks," wrote Vint Cerf - who worked on solving this problem in the early 1980s - on Google's blog yesterday.

The standard, eventually completed by Cerf and colleague Robert Kahn, was named Transmission Control Protocol (TCP). This later spawned a protocol for real-time data, named "Internet Protocol" (IP).

Tested across three types of networks by DARPA, it was soon adopted as the new standard. 1 January 1983 was the day on which, after successful migration of 400 hosts from the earlier NCP (Network Control Protocol), those who hadn't switched "would be cut off", said Cerf.

TCP/IP continues to be the underlying mechanism by which internet data is transmitted. If Tim Berners-Lee provided the wheels that got the internet rolling, it was Cerf and Kahn who first fired up the engine that drives it all.