ARPANET

The Advanced Research Projects Agency Network (ARPANET) was the first wide-area

The first computers were connected in 1969 and the Network Control Protocol was implemented in 1970, development of which was led by Steve Crocker at UCLA and other graduate students, including Jon Postel and Vint Cerf.^[7][8] The network was declared operational in 1971. Further software development enabled remote login and file transfer, which was used to provide an early form of email.^[9] The network expanded rapidly and operational control passed to the Defense Communications Agency in 1975.

Bob Kahn moved to DARPA and, together with Vint Cerf at

Historically, voice and data communications were based on methods of circuit switching, as exemplified in the traditional telephone network, wherein each telephone call is allocated a dedicated end-to-end electronic connection between the two communicating stations. The connection is established by switching systems that connected multiple intermediate call legs between these systems for the duration of the call.

The traditional model of the circuit-switched telecommunication network was challenged in the early 1960s by Paul Baran at the RAND Corporation, who had been researching systems that could sustain operation during partial destruction, such as by nuclear war. He developed the theoretical model of distributed adaptive message block switching.^[14] However, the telecommunication establishment rejected the development in favor of existing models. Donald Davies at the United Kingdom's National Physical Laboratory (NPL) independently arrived at a similar concept in 1965.^[15][16]

The earliest ideas for a

Sutherland and Taylor continued their interest in creating the network, in part, to allow ARPA-sponsored researchers at various corporate and academic locales to utilize computers provided by ARPA, and, in part, to quickly distribute new software and other computer science results.^[18] Taylor had three computer terminals in his office, each connected to separate computers, which ARPA was funding: one for the System Development Corporation (SDC) Q-32 in Santa Monica, one for Project Genie at the University of California, Berkeley, and another for Multics at the Massachusetts Institute of Technology. Taylor recalls the circumstance: "For each of these three terminals, I had three different sets of user commands. So, if I was talking online with someone at S.D.C., and I wanted to talk to someone I knew at Berkeley, or M.I.T., about this, I had to get up from the S.D.C. terminal, go over and log into the other terminal and get in touch with them. I said, 'Oh Man!', it's obvious what to do: If you have these three terminals, there ought to be one terminal that goes anywhere you want to go. That idea is the ARPANET".^[19]

Donald Davies' work caught the attention of ARPANET developers at Symposium on Operating Systems Principles in October 1967.^[20] He gave the first public presentation, having coined the term packet switching, in August 1968 and incorporated it into the NPL network in England.^[21][22] The NPL network and ARPANET were the first two networks in the world to use packet switching.^[23][24][25] Roberts said the packet switching networks built in the 1970s were similar "in nearly all respects" to Davies' original 1965 design.^[26]

Creation

In February 1966, Bob Taylor successfully lobbied ARPA's Director Charles M. Herzfeld to fund a network project. Herzfeld redirected funds in the amount of one million dollars from a ballistic missile defense program to Taylor's budget.^[27] Taylor hired Larry Roberts as a program manager in the ARPA Information Processing Techniques Office in January 1967 to work on the ARPANET.^[28] Roberts met Paul Baran in February 1967, but did not discuss networks.^[29][30]

Roberts asked Frank Westervelt to explore the initial design questions for a network.^[28] In April 1967, ARPA held a design session on technical standards. The initial standards for identification and authentication of users, transmission of characters, and error checking and retransmission procedures were discussed.^[31] Roberts' proposal was that all mainframe computers would connect to one another directly. The other investigators were reluctant to dedicate these computing resources to network administration. Wesley Clark proposed minicomputers should be used as an interface to create a message switching network. Roberts modified the ARPANET plan to incorporate Clark's suggestion and named the minicomputers Interface Message Processors (IMPs).^{[28][32][33][34]}

The plan was presented at the inaugural Symposium on Operating Systems Principles in October 1967.^[35] Donald Davies' work on packet switching and the NPL network, presented by a colleague (Roger Scantlebury), came to the attention of the ARPA investigators at this conference.^[36][20] Roberts applied Davies' concept of packet switching for the ARPANET,^[37][38] and sought input from Paul Baran.^[39] The NPL network was using line speeds of 768 kbit/s, and the proposed line speed for the ARPANET was upgraded from 2.4 kbit/s to 50 kbit/s.^[40]

By mid-1968, Roberts and Barry Wessler wrote a final version of the IMP specification based on a

The initial, seven-person BBN team were much aided by the technical specificity of their response to the ARPA RFQ, and thus quickly produced the first working system. The "IMP guys" were led by Frank Heart and the theoretical design of the network was led by Bob Kahn; the team included Dave Walden, Severo Omstein, William Crowther and several others.^[41][42][43] The BBN-proposed network closely followed Roberts' ARPA plan: a network composed of small computers, the IMPs (similar to the later concept of routers), that functioned as gateways interconnecting local resources. Routing, flow control, software design and network control were developed by the BBN IMP team.^[41][44] At each site, the IMPs performed store-and-forward packet switching functions and were interconnected with leased lines via telecommunication data sets (modems), with initial data rates of 56kbit/s. The host computers were connected to the IMPs via custom serial communication interfaces. The system, including the hardware and the packet switching software, was designed and installed in nine months.^[23][34][45] The BBN team continued to interact with the NPL team with meetings between them taking place in the U.S. and the U.K.^[46][47]

The first-generation IMPs were built by BBN Technologies using a

The ARPANET was not started to create a Command and Control System that would survive a nuclear attack, as many now claim. To build such a system was, clearly, a major military need, but it was not ARPA's mission to do this; in fact, we would have been severely criticized had we tried. Rather, the ARPANET came out of our frustration that there were only a limited number of large, powerful research computers in the country, and that many research investigators, who should have access to them, were geographically separated from them.[49]

According to Stephen J. Lukasik, who as deputy director (1967–1970) and Director of DARPA (1970–1975)^[50] was the person who signed most of the checks for Arpanet's development, the goal was "command and control":

The goal was to exploit new computer technologies to meet the needs of military command and control against nuclear threats, achieve survivable control of US nuclear forces, and improve military tactical and management decision making.^[51]

The ARPANET did use distributed computation, and incorporated frequent re-computation of routing tables (automatic routing was technically challenging at the time). These features increased the survivability of the network in the event of significant interruption. Furthermore, the ARPANET was designed to survive subordinate-network losses.^[52][53] However, the Internet Society agrees with Herzfeld in a footnote in their online article, A Brief History of the Internet:

It was from the RAND study that the false rumor started, claiming that the ARPANET was somehow related to building a network resistant to nuclear war. This was never true of the ARPANET, but was an aspect of the earlier RAND study of secure communication. The later work on internetworking did emphasize robustness and survivability, including the capability to withstand losses of large portions of the underlying networks.^[54]

The first four IMPs were:^[1]

• University of California, Los Angeles (UCLA), where Leonard Kleinrock had established a Network Measurement Center, with an SDS Sigma 7 being the first computer attached to it;
• The Augmentation Research Center at Stanford Research Institute (now SRI International), where Douglas Engelbart had created the new NLS system, an early hypertext system, and would run the Network Information Center (NIC), with the SDS 940 that ran NLS, named "Genie", being the first host attached;
• OS/MVT
  being the machine attached;
• The University of Utah School of Computing, where Ivan Sutherland had moved, running a DEC PDP-10 operating on TENEX.

The first successful host-to-host connection on the ARPANET was made between Stanford Research Institute (SRI) and UCLA, by SRI programmer Bill Duvall and UCLA student programmer Charley Kline, at 10:30 pm PST on 29 October 1969 (6:30 UTC on 30 October 1969).

Elizabeth Feinler created the first Resource Handbook for ARPANET in 1969 which led to the development of the ARPANET directory.^[64] The directory, built by Feinler and a team made it possible to navigate the ARPANET.^[65][66]

Growth and evolution

Roberts engaged Howard Frank to consult on the topological design of the network. Frank made recommendations to increase throughput and reduce costs in a scaled-up network.^[67] By March 1970, the ARPANET reached the East Coast of the United States, when an IMP at BBN in Cambridge, Massachusetts was connected to the network. Thereafter, the ARPANET grew: 9 IMPs by June 1970 and 13 IMPs by December 1970, then 18 by September 1971 (when the network included 23 university and government hosts); 29 IMPs by August 1972, and 40 by September 1973. By June 1974, there were 46 IMPs, and in July 1975, the network numbered 57 IMPs. By 1981, the number was 213 host computers, with another host connecting approximately every twenty days.^[1]

Support for inter-IMP circuits of up to 230.4 kbit/s was added in 1970, although considerations of cost and IMP processing power meant this capability was not actively used.

Larry Roberts saw the ARPANET and

1971 saw the start of the use of the non-ruggedized (and therefore significantly lighter) Honeywell 316 as an IMP. It could also be configured as a Terminal Interface Processor (TIP), which provided terminal server support for up to 63 ASCII serial terminals through a multi-line controller in place of one of the hosts.^[70] The 316 featured a greater degree of integration than the 516, which made it less expensive and easier to maintain. The 316 was configured with 40 kB of core memory for a TIP. The size of core memory was later increased, to 32 kB for the IMPs, and 56 kB for TIPs, in 1973.

The ARPANET was demonstrated at the International Conference on Computer Communications in October 1972.

In 1975, BBN introduced IMP software running on the

Network performance

In 1968, Roberts contracted with Kleinrock to measure the performance of the network and find areas for improvement.^[39][71][72] Building on his earlier work on queueing theory, Kleinrock specified mathematical models of the performance of packet-switched networks, which underpinned the development of the ARPANET as it expanded rapidly in the early 1970s.^[23][36][39]

Operation

ARPA was intended to fund advanced research. The ARPANET was a research project that was communications-oriented, rather than user-oriented in design.^[73] Nonetheless, in the summer of 1975, operational control of the ARPANET passed to the Defense Communications Agency.^[1] At about this time, the first ARPANET encryption devices were deployed to support classified traffic.

The ARPANET Completion Report, published in 1981 jointly by BBN and DARPA,^[74] concludes that:

 ... it is somewhat fitting to end on the note that the ARPANET program has had a strong and direct feedback into the support and strength of computer science, from which the network, itself, sprang.^[75]

CSNET, expansion

Access to the ARPANET was expanded in 1981 when the National Science Foundation (NSF) funded the Computer Science Network (CSNET).

Adoption of TCP/IP

The transatlantic connectivity with NORSAR and UCL later evolved into the SATNET. The ARPANET, SATNET and PRNET were interconnected in 1977.

The DoD made

On January 1, 1983, known as flag day, TCP/IP protocols became the standard for the ARPANET, replacing the earlier Network Control Protocol.^[78][12]

MILNET, phasing out

In September 1984 work was completed on restructuring the ARPANET giving U.S. military sites their own Military Network (MILNET) for unclassified defense department communications.^[79][80] Both networks carried unclassified information and were connected at a small number of controlled gateways which would allow total separation in the event of an emergency. MILNET was part of the Defense Data Network (DDN).^[81]

Separating the civil and military networks reduced the 113-node ARPANET by 68 nodes. After MILNET was split away, the ARPANET would continue to be used as an Internet backbone for researchers, but be slowly phased out.

Decommissioning

In 1985, the NSF funded the establishment of national supercomputing centers at several universities and provided network access and network interconnectivity with the

The ARPANET project was formally decommissioned in 1990. The original IMPs and TIPs were phased out as the ARPANET was shut down after the introduction of the NSFNet, but some IMPs remained in service as late as July 1990.^[82][83]

In the wake of the decommissioning of the ARPANET on 28 February 1990, Vinton Cerf wrote the following lamentation, entitled "Requiem of the ARPANET":^[84]

It was the first, and being first, was best,
but now we lay it down to ever rest.
Now pause with me a moment, shed some tears.
For

auld lang syne

, for love, for years and years
of faithful service, duty done, I weep.
Lay down

packet

, now, O friend, and sleep.

-

Vinton Cerf

Legacy

The technological advancements and practical applications achieved through the ARPANET were instrumental in shaping modern computer networking including the Internet. Development and implementation of the concepts of packet switching, decentralized communication, and the development of protocols like TCP/IP laid the foundation for a global network that revolutionized communication, information sharing and collaborative research across the world.^[86]

The ARPANET was related to many other research projects, which either influenced the ARPANET design, or which were ancillary projects or spun out of the ARPANET.

Senator

Software and protocols

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IMP functionality

Because it was never a goal for the ARPANET to support IMPs from vendors other than BBN, the IMP-to-IMP protocol and message format were not standardized. However, the IMPs did nonetheless communicate amongst themselves to perform link-state routing, to do reliable forwarding of messages, and to provide remote monitoring and management functions to ARPANET's Network Control Center. Initially, each IMP had a 6-bit identifier and supported up to 4 hosts, which were identified with a 2-bit index. An ARPANET host address, therefore, consisted of both the port index on its IMP and the identifier of the IMP, which was written with either port/IMP notation or as a single byte; for example, the address of MIT-DMG (notable for hosting development of Zork) could be written as either 1/6 or 70. An upgrade in early 1976 extended the host and IMP numbering to 8-bit and 16-bit, respectively.^{[citation needed]}

In addition to primary routing and forwarding responsibilities, the IMP ran several background programs, titled TTY, DEBUG, PARAMETER-CHANGE, DISCARD, TRACE, and STATISTICS. These were given host numbers in order to be addressed directly and provided functions independently of any connected host. For example, "TTY" allowed an on-site operator to send ARPANET packets manually via the teletype connected directly to the IMP.^{[citation needed]}

1822 protocol

The starting point for host-to-host communication on the ARPANET in 1969 was the

NCP was developed under the leadership of Steve Crocker, then a graduate student at UCLA. Crocker created and led the Network Working Group (NWG) which was made up of a collection of graduate students at universities and research laboratories, including Jon Postel and Vint Cerf at UCLA. They were sponsored by ARPA to carry out the development of the ARPANET and the software for the host computers that supported applications.

Network applications

NCP provided a standard set of network services that could be shared by several applications running on a single host computer. This led to the evolution of application protocols that operated, more or less, independently of the underlying network service, and permitted independent advances in the underlying protocols.^{[citation needed]}

The various application protocols such as

Telnet was developed in 1969 beginning with RFC 15, extended in RFC 855.^[citation needed]

The original specification for the File Transfer Protocol was written by

The Purdy Polynomial hash algorithm was developed for the ARPANET to protect passwords in 1971 at the request of Larry Roberts, head of ARPA at that time. It computed a polynomial of degree 2²⁴ + 17 modulo the 64-bit prime p = 2⁶⁴ − 59. The algorithm was later used by Digital Equipment Corporation (DEC) to hash passwords in the VMS operating system and is still being used for this purpose.^{[citation needed]}

Rules and etiquette

Because of its government funding, certain forms of traffic were discouraged or prohibited.

Leonard Kleinrock claims to have committed the first illegal act on the Internet, having sent a request for return of his electric razor after a meeting in England in 1973. At the time, use of the ARPANET for personal reasons was unlawful.^[97]

In 1978, against the rules of the network, Gary Thuerk of

• George W. Mitchell
  .
• "Scenario", an episode of the U.S. television sitcom Benson (season 6, episode 20—dated February 1985), was the first incidence of a popular TV show directly referencing the Internet or its progenitors. The show includes a scene in which the ARPANET is accessed.^[100]
• There is an
  NTT DoCoMo, dedicated to the mobile communications giant based in Japan.^{[citation needed}
  ]
• Thomas Pynchon mentions the ARPANET in his 2009 novel Inherent Vice, which is set in Los Angeles in 1970, and in his 2013 novel Bleeding Edge.^[101]
• The 1993 television series
  better source needed
  ]
• In the spy-drama television series The Americans, a Russian scientist defector offers access to ARPANET to the Russians in a plea to not be repatriated (Season 2 Episode 5 "The Deal"). Episode 7 of Season 2 is named 'ARPANET' and features Russian infiltration to bug the network.
• In the television series Person of Interest, main character Harold Finch hacked the ARPANET in 1980 using a homemade computer during his first efforts to build a prototype of the Machine.^[103][104] This corresponds with the real life virus that occurred in October of that year that temporarily halted ARPANET functions.^[105][106] The ARPANET hack was first discussed in the episode 2PiR (stylised 2${\displaystyle \pi }$R) where a computer science teacher called it the most famous hack in history and one that was never solved. Finch later mentioned it to Person of Interest Caleb Phipps and his role was first indicated when he showed knowledge that it was done by "a kid with a homemade computer" which Phipps, who had researched the hack, had never heard before.
• In the third season of the television series Halt and Catch Fire, the character Joe MacMillan explores the potential commercialization of the ARPANET.

See also

• .arpa – top-level domain used exclusively for technical infrastructure purposes
• Computer Networks: The Heralds of Resource Sharing – 1972 documentary film
• History of the Internet
• List of Internet pioneers
• OGAS – Soviet internet-like project, automation of economy
• Plan 55-A
• Protocol Wars
• Usenet – Worldwide computer-based distributed discussion system, "A Poor Man's ARPAnet"

References

Sources

• Evans, Claire L. (2018). Broad Band: The Untold Story of the Women Who Made the Internet. New York: Portfolio/Penguin.
  ISBN 978-0-7352-1175-9
  .
• Hafner, Katie; Lyon, Matthew (1996). Where Wizards Stay Up Late: The Origins of the Internet. Simon and Schuster.
  ISBN 978-0-7434-6837-4
  .

Further reading

• Norberg, Arthur L.; O'Neill, Judy E. (1996). Transforming Computer Technology: Information Processing for the Pentagon, 1962–1982. Johns Hopkins University. pp. 153–196.
  ISBN 978-0-8018-6369-1
  .
• A History of the ARPANET: The First Decade (PDF) (Report). Arlington, VA:
  Bolt, Beranek & Newman Inc. 1 April 1981. Archived
  from the original on 1 December 2012.
• Abbate, Janet (2000).
  ISBN 978-0-2625-1115-5
  .
• ISBN 978-1-4302-0869-3
  .
• ISBN 978-0-201-87674-1
  .
• Waldrop, M. Mitchell (23 August 2001). The Dream Machine: J. C. R. Licklider and the Revolution That Made Computing Personal. New York: Viking.
  ISBN 978-0-670-89976-0
  .
• "The Computer History Museum, SRI International, and BBN Celebrate the 40th Anniversary of First ARPANET Transmission". Computer History Museum. 27 October 2009.

Oral histories

• Kahn, Robert E. (24 April 1990). "Oral history interview with Robert E. Kahn". University of Minnesota, Minneapolis:
  Charles Babbage Institute
  . Retrieved 15 May 2008. Focuses on Kahn's role in the development of computer networking from 1967 through the early 1980s. Beginning with his work at BBN, Kahn discusses his involvement as the ARPANET proposal was being written and then implemented, and his role in the public demonstration of the ARPANET. The interview continues into Kahn's involvement with networking when he moves to IPTO in 1972, where he was responsible for the administrative and technical evolution of the ARPANET, including programs in packet radio, the development of a new network protocol (TCP/IP), and the switch to TCP/IP to connect multiple networks.
• Cerf, Vinton G. (24 April 1990). "Oral history interview with Vinton Cerf". University of Minnesota, Minneapolis:
  Charles Babbage Institute
  . Retrieved 1 July 2008. Cerf describes his involvement with the ARPA network, and his relationships with Bolt Beranek and Newman, Robert Kahn, Lawrence Roberts, and the Network Working Group.
• Baran, Paul (5 March 1990). "Oral history interview with Paul Baran". University of Minnesota, Minneapolis:
  Charles Babbage Institute
  . Retrieved 1 July 2008. Baran describes his work at RAND, and discusses his interaction with the group at ARPA who were responsible for the later development of the ARPANET.
• Kleinrock, Leonard (3 April 1990). "Oral history interview with Leonard Kleinrock". University of Minnesota, Minneapolis:
  Charles Babbage Institute
  . Retrieved 1 July 2008. Kleinrock discusses his work on the ARPANET.
• Roberts, Lawrence G. (4 April 1989). "Oral history interview with Larry Roberts". University of Minnesota, Minneapolis:
  Charles Babbage Institute
  . Retrieved 1 July 2008.
• Lukasik, Stephen (17 October 1991). "Oral history interview with Stephen Lukasik". University of Minnesota, Minneapolis:
  Charles Babbage Institute
  . Retrieved 1 July 2008. Lukasik discusses his tenure at the Advanced Research Projects Agency (ARPA), the development of computer networks and the ARPANET.
• Frank, Howard (30 March 1990). "Oral history interview with Howard Frank". University of Minnesota, Minneapolis:
  Charles Babbage Institute
  . Retrieved 1 July 2008. Frank describes his work on the ARPANET, including his interaction with Roberts and the IPT Office.

Detailed technical reference works

• Marill, Thomas;
  S2CID 2051631. Archived from the original
  on 1 April 2002.
• Roberts, Lawrence G. (1967). "Multiple computer networks and intercomputer communication". Proceedings of the first ACM symposium on Operating System Principles (SOSP '67). Association for Computing Machinery. pp. 3.1–3.6.
  S2CID 17409102. Archived from the original
  on 3 June 2002.
• S2CID 15215451
  .
• Roberts, Lawrence G.; Wessler, Barry D. (1970). "Computer network development to achieve resource sharing". Proceedings of the May 5-7, 1970, Spring Joint Computer Conference (AFIPS '70 (Spring)). Association for Computing Machinery. pp. 543–9.
  S2CID 9343511
  .
• Heart, Frank;
  doi:10.1145/1476936.1477021
  .
• Carr, Stephen;
  RFC 33
  .
• doi:10.1145/1478873.1478906
  .
• doi:10.1145/1480083.1480096
  .
• Heart, Frank;
  doi:10.1145/1476936.1477021
  .
• Carr, Stephen;
  RFC 33
  .
• doi:10.1145/1478873.1478906
  .
• Feinler, E.; Postel, J. (1976). ARPANET Protocol Handbook. SRI International.
  OCLC 2817630
  . NTIS ADA027964.
• OCLC 7955574
  . NIC 7104, NTIS ADA052594.
• Feinler, E.J.; Landsberden, J.M.; McGinnis, A.C. (1976). ARPANET Resource Handbook. Stanford Research Institute.
  OCLC 1110650114
  . NTIS ADA040452.
  • NTIS documents may be available from "National Technical Reports Library". NTIS National Technical Information Service. U.S. Department of Commerce. 2014.
• S2CID 26876676. Archived from the original
  on 24 March 2016. Retrieved 3 September 2005.
• S2CID 24271168. Archived from the original
  on 24 March 2016.

External links

Wikimedia Commons has media related to ARPANET.

• "ARPANET Maps 1969 to 1977". California State University, Dominguez Hills (CSUDH). 4 January 1978. Archived from the original on 19 April 2012. Retrieved 17 May 2012.
• Walden, David C. (February 2003). "Looking back at the ARPANET effort, 34 years later". Living Internet. East Sandwich, Massachusetts. Retrieved 19 March 2021.
• "Images of ARPANET from 1964 onwards". The Computer History Museum. Retrieved 29 August 2004. Timeline.
• "Paul Baran and the Origins of the Internet". RAND Corporation. Retrieved 3 September 2005.
• Kleinrock, Leonard. "The Day the Infant Internet Uttered its First Words". UCLA. Retrieved 11 November 2004. Personal anecdote of the first message ever sent over the ARPANET
• "Doug Engelbart's Role in ARPANET History". 2008. Retrieved 3 September 2009.
• Waldrop, Mitch (April 2008). "DARPA and the Internet Revolution". 50 years of Bridging the Gap. DARPA. pp. 78–85. Archived from the original on 15 September 2012. Retrieved 26 August 2012.
• "Robert X Cringely: A Brief History of the Internet". YouTube. Archived from the original on 20 March 2013.