ARPANET

The ARPANET was the first packet-based wide-area network; so called because it was initiated, and initially funded, by ARPA.

It consisted of minicomputers called Interface Message Processors ('IMPs', for short) running specialized packet switching code, joined together with synchronous serial lines; host computers were connected to the IMPs by special bit-serial interfaces (see below).

Protocols

The protocol family used on the early ARPANET included:

• The Host-to-IMP Protocol, the bottom layer; specified in BBN Report #1822 (multiple editions over time)
• ICP, Initial connection protocol
• Host-to-Host Protocol (early version here)

These two latter protocols formed the Network Control Program, which all the application protocols ran over.

Those included:

• FTP (early version here)
• TELNET
• MAIL (here is a much later proposal which eventually became SMTP)
• NAME/FINGER

Further reading

• F.E. Heart, R.E. Kahn, S.M. Ornstein, W.R. Crowther, and D.C. Walden, "The interface message processor for the ARPA computer network", Proceedings AFIPS, 1970 SJCC, Vol. 36, pp. 551-567.
• J.M. McQuillan, W.R. Crowther, B.P. Cosell, D.C. Walden, and F.E. Heart, "Improvements in the Design and Performance of the ARPA Network", Proceedings AFIPS, 1972 FJCC, Vol. 40, pp. 741-754.
• John M. McQuillan, David C. Walden, "The ARPA Network Design Decisions", in "Computer Networks", Vol. 1, No. 5, August 1977, pp. 243-289.

External links

• ARPANET Technical Information
  • ARPANET Technical Information: Geographic Maps
  • ARPANET Technical Information: Logical Maps
  • ARPANET Technical Information: Packet Formats
  • ARPANET Technical Information: ARPANET Protocol Handbook
• Early Experiences with the ARPANET and INTERNET in the UK