Computer networking began in 1940 with a teletype and a very long cable
In 1940 George Stibitz sat a teletype at Dartmouth and had it drive his calculator at Bell Labs in New York, the first time anyone used a computer remotely in real time. From that link grew radar networks, a memo about an intergalactic computer network, and eventually the internet that almost every device now joins.
Early links were painfully slow. America's SAGE air-defence radar network of the late 1950s used AT&T's Bell 101, the first commercial computer modem, sending 110 bits per second over ordinary phone lines. In 1960 the SABRE airline booking system went live on two linked mainframes. Time-sharing, patented by Christopher Strachey and pursued by John McCarthy at MIT from 1959, let many users share one machine. In the Soviet Union, Anatoly Kitov proposed a network of computing centres to run the army and economy in 1959; party leaders rejected it.
The key idea came twice. In the 1960s Paul Baran in the United States and Donald Davies in Britain independently hit on chopping messages into small blocks, each routed on its own. Davies built a working local network at Britain's National Physical Laboratory in 1968 and 1969. Meanwhile J. C. R. Licklider's memos about an intergalactic computer network led to ARPANET, whose first four sites, in California and Utah, connected in 1969. Leonard Kleinrock's mathematics modelled how such networks perform.
The early 1970s filled in the rest. France's CYCLADES network made the computers at each end, not the network, responsible for reliable delivery. Robert Metcalfe and David Boggs at Xerox PARC designed Ethernet, inspired by a Hawaiian packet-radio system. Peter Kirstein linked ARPANET to British academic networks, the first international network of mixed types. In 1974 Vint Cerf and Bob Kahn published their internetworking paper, and a follow-up specification shortened internetworking to Internet.
Ethernet started at 2.94 megabits per second, reached a gigabit by 1998 and 800 gigabits by 2025. Physical links today range from twisted copper pairs to optical fibre, which carries many streams on different wavelengths across ocean floors, plus Wi-Fi, cellular radio and satellites parked about 35,400 kilometres above the equator.
Source: Computer network
