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Network Control Program

Last Edit: 10/01/17

The Network Control Program was the original transport protocol of ARPANET. ARPANET was a computer network that was a precursor to the Internet. ARPANET was one of the first computer networks to incorporate packet switching - packet switching underpins the transport of data on the Internet. The plan for ARPANET was developed by Larry Roberts in 1968, the network was built by BBN Technologies in 1969, and the first message was sent on the network on the 29th of October, 1969.

Larry Roberts led a team of graduate students to create ARPANET. One of the members of this team was Stephen D. Crocker; who would later form a Network Working Group (NWG). Crocker admitted that there was no 'great plan' behind the creation of the protocols which underpinned ARPANET: instead the process was largely accidental, with Crocker admitting in RFC-1000 that Larry Roberts would on a number of occasions "send us back to the drawing board".

Crocker states that it was in the "spring and summer of 1969" that they "grappled" and developed a detailed protocol design for ARPANET. The protocols they designed would eventually evolve into Telnet, File Transfer Protocol (TCP) and most importantly the Network Control Program (NCP). While NCP was first devised as a host-host protocol, and would be responsible for transporting data packets across ARPANET. NCP implemented two (odd and even) simplex ports for each application layer protocol. NCP was launched by the Network Working Group (NWG) in 1970, and is credited with standardising the network interface of ARPANET.

Due to some perceived limitations of NCP, a new 'open' architecture for ARPANET was envisaged by Robert E. Kahn in the early 1970's. Built upon the ideas of NCP, the Transmission Control Protocol was released in 1974 by Robert E. Kahn and Vinton Cerf. The Transmission Control Protocol was eventually split into 2 protocols and standardised as TCP/IP in 1980. ARPANET changed from using NCP to TCP/IP on the 1st of January, 1983. This date is viewed as the day the Internet was born; due to Vinton Cerf titling a RFC document the 'Internet Transmission Control Program' in 1974.