NCP -- Network Control Program

With the pressure to get something working and the general confusion as to how to achieve the high generality we all aspired to, we punted and defined the first set of protocols to include only Telnet and FTP functions.

In December 1969, we met with Larry Roberts in Utah, and suffered our first direct experience with ‘redirection’. Larry made it abundantly clear that our first step was not big enough, and we went back to the drawing board. Over the next few months we designed a symmetric host-host protocol, and we defined an abstract implementation of the protocol known as the Network Control Program.

Along with the basic host-host protocol, we also envisioned a hierarchy of protocols, with Telnet, FTP and some splinter protocols as the first examples. If we had only consulted the ancient mystics, we would have seen immediately that seven layers were required.

– Stephen D. Crocker, RFC 1000, The Request For Comments Reference Guide.

The Network Control Protocol (NCP) was the first standard networking protocol on the ARPANET. NCP was finalized and deployed in December 1970 by the Network Working Group (NWG), led by Steve Crocker, also the inventor of the Request For Comments.

NCP standardized the ARPANET network interface, making it easier to establish, and enabling more and more DARPA sites to join the network. In October 1971, every site on the ARPANET logged into every other site (with one exception) over NCP at a meeting in Massachusetts at the Massachusetts Institute of Technology.

By the end of 1971 there were fifteen sites using NCP on the young Internet:

  • Bolt Baranek and Newman
  • Carnegie Mellon University
  • Case Western Reserve University
  • Harvard University
  • Lincoln Laboratories
  • Massachusetts Institute of Technology
  • NASA at AMES
  • RAND Corporation
  • Stanford Research Institute
  • Stanford University
  • System Development Corporation
  • University of California at Los Angeles
  • University of California of Santa Barbara
  • University of Illinois at Urbana
  • University of UTAH

Robert Kahn and Vinton Cerf later built on NCP to develop the standard TCP/IP networking protocol still used on the Internet today.

RFC’s. Requests For Comments describing NCP are listed below:

  • RFC 33; Crocker, S.; Carr, S.; Cerf, V.; New HOST-HOST Protocol; 12 Feb 1973.
  • RFC 36; Crocker, S.; Protocol Notes; 16 Mar 1970 .

  • RFC 78; Harslem, E.; Heafner, J.; White, J.; NCP Status Report: UCSB/RAND; Nov 1970.