July 15, 2024

ARPANET Protocols


ARPANET protocols were created by the Network Working Group. A protocol is a kind of standard, an agreement for a representation. The agreed means (form) of communication (providing content/meaning) between parties (people, computers). Computer protocols define rules governing formats and the means of data exchange within the context of a task, e.g. e-mail exchange, establishing remote connections, file transfer. Technical standards create a stabilty for developers and manufacturers.

Standards are reached by:

  • Agreement between international or professional bodies;
  • A company achieving market dominanace, e.g. Windows and MS (de-facto standards)

Examples of Internet protocols

  • HTTP protocol (Hypertext Transfer Protocol) to request and receive Web pages
  • TCP/IP, used for the transfer of data across the Internet. Many of the Internet protocols are, inevitably, concerned with passing messages. Typically they will specify the format that a message must take. In the case of an e-mail message, for example, both the format of the electronic mail message and the way that it is transmitted across the network are described and governed by protocols. These ensure that electronic mail messages are correctly formatted and transmitted from the originating computer to the destination computer. TCP/IP adopts a layered approach to protocols (see TCP/IP and Packets)
  • SMTP (Simple Mail Transfer Protocol), used to send and receive electronic mail
  • FTP (File Transfer Protocol), used to transfer files between computers
  • NNTP (Network News Transfer Protocol)- to transmit network (Usenet) news.

The Internet is more complex than ARPANET; more protocols were needed. NWG created Network Control Protocol (NCP), which enabled different hosts on the network to communicate. This was crucial to the development of the Internet. NWG also developed Telnet (for logging in to remote hosts) and File Transfer Protocol (FTP) for the secure transfer of files between hosts.


Wizards Chapter 5 discusses:

  • Implementation and installation of the early nodes of the ARPANET
  • Development of protocols - Network Working Group established
  • Robert Kahn's concerns about overall systems failure (especially due to 'lock-up') justified.
  • Steve Crocker, Jon Postel and Vint Cerf

Wizards Chapter 6 discusses:

  • ARPANET grew at a rate of a node a month from the original four-node system based round UCLA, SRI, University of California at Santa Barbara and Utah.
  • ARPANET evolved into cross-country (USA) links
  • BBN took control of network and was able to perform remote installation of software upgrades and diagnostic work.
  • Kahn organised a demonstration of the network in Washington D.C. in the autumn of 1972.
  • The Honeywell 516 was replaced by the 316 as the basic IMP machine. The development of the TIP (Terminal IMP) interface was devised to enable a number of terminals to link to an IMP. (Note that Davies and NPL had already solved this problem)
  • Finalisation of Telnet (remote log-in) and FTP (file transfer) protocols


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