NCP (Network Control Program)
More info
- Creator
- Network Working Group
- Released
- 1970
- Type
- Protocol
- Successor
- TCP/IP
ARPANET's first host-to-host protocol, which let machines on the network open connections to each other until TCP/IP replaced it in 1983.
In 1969 the graduate students of the Network Working Group, led by Steve Crocker, were about to receive working network hardware and had no idea yet what the computers should say to each other. Their answer was NCP, rolled out across the hosts in 1970–71. It managed connections between programs through numbered sockets, and the first versions of Telnet and FTP ran on top of it.
NCP trusted the IMPs completely to deliver everything in order and intact. Inside a single network that worked; between networks, where nobody could promise anything, it didn't. Hence TCP/IP, and on flag day, 1 January 1983, NCP was switched off. The letters survive in the retrofitted name "Network Control Protocol".