HOME

TheInfoList




The Advanced Research Projects Agency Network (ARPANET) was the first wide-area
packet-switching In telecommunications, packet switching is a method of grouping data that is transmitted over a digital network into '' packets''. Packets are made of a header (computing), header and a payload (computing), payload. Data in the header is used by ...
network with distributed control and one of the first networks to implement the
TCP/IP The Internet protocol suite, commonly known as TCP/IP, is the set of communications protocol A communication protocol is a system of rules that allows two or more entities of a communications system 400px, Communication system A commu ...
protocol suite. Both technologies became the technical foundation of the
Internet The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a ''internetworking, network of networks'' that consist ...

Internet
. The ARPANET was established by the
Advanced Research Projects Agency The Defense Advanced Research Projects Agency (DARPA) is a research and development agency of the United States Department of Defense The United States Department of Defense (DoD, USDOD or DOD) is an United States federal executive depart ...
(ARPA) of the
United States Department of Defense The United States Department of Defense (DoD, USDOD or DOD) is an executive branch department of the federal government A federation (also known as a federal state) is a political entity A polity is an identifiable political entityâ ...
. Building on the ideas of
J. C. R. Licklider
J. C. R. Licklider
, Bob Taylor initiated the ARPANET project in 1966 to enable access to remote computers. Taylor appointed Larry Roberts as program manager. Roberts made the key decisions about the network design. He incorporated
Donald Davies Donald Watts Davies, (7 June 1924 – 28 May 2000) was a Welsh computer scientist A computer scientist is a person who has acquired the knowledge of computer science Computer science deals with the theoretical foundations of informati ...

Donald Davies
’ concepts and designs for packet switching, and sought input from
Paul Baran Paul Baran (born Pesach Baran ; April 29, 1926 – March 26, 2011) was a Polish-American engineer who was a pioneer in the development of computer networks. He was one of the two independent inventors of packet switching, which is today the domin ...
. ARPA awarded the contract to build the network to
Bolt Beranek & Newman Raytheon BBN Technologies (originally Bolt Beranek and Newman Inc.) was an American research and development company, based next to Fresh Pond in Cambridge, Massachusetts Cambridge ( ) is a city in Middlesex County, Massachusetts, Middlesex C ...
who developed the first
protocol Protocol may refer to: Sociology and politics * Protocol (politics) Protocol originally (in Late Middle English, c. 15th century) meant the minutes or logbook taken at a meeting, upon which an agreement was based. The term now commonly refers to a ...
for the network. Roberts engaged
Leonard Kleinrock Leonard Kleinrock (born June 13, 1934) is an American computer scientist. A professor at UCLA's Henry Samueli School of Engineering and Applied Science, he made several important contributions to the field of computer science, in particular to ...
at
UCLA The University of California, Los Angeles (UCLA) is a public In public relations Public relations (PR) is the practice of managing and disseminating information from an individual or an organization An organization, or organ ...
to develop mathematical methods for analyzing the packet network technology. The first computers were connected in 1969 and the
Network Control Program The Network Control Program (NCP) provided the middle layers of the protocol stack running on host computers of the ARPANET, the predecessor to the modern Internet The Internet (Capitalization of Internet, or internet) is the global ...
was implemented in 1970. Further software development enabled remote login,
file transfer File transfer is the Transmission (telecommunications), transmission of a computer file through a communication channel from one computer system to another. Typically, file transfer is mediated by a communications protocol. In the history of compu ...
and
email upThe email_address.html"_;"title="at_sign,_a_part_of_every_SMTP_email_address">at_sign,_a_part_of_every_SMTP_email_address Electronic_mail_(email_or_e-mail)_is_a_method_of_exchanging_messages_("mail")_between_people_using_electronic_dev ...

email
. The network expanded rapidly and was declared operational in 1975 when control passed to the
Defense Communications Agency The Defense Information Systems Agency (DISA), known as the Defense Communications Agency (DCA) until 1991, is a United States Department of Defense The United States Department of Defense (DoD, USDOD or DOD) is an United States federal exec ...
.
Internetworking Internetworking is the practice of interconnecting multiple computer networks, such that any pair of Host (network), hosts in the connected networks can exchange messages irrespective of their hardware-level networking technology. The resulting s ...
research in the early 1970s by
Bob Kahn Robert Elliot Kahn (born December 23, 1938) is an American electrical engineer Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems which use electricity, e ...

Bob Kahn
at
DARPA The Defense Advanced Research Projects Agency (DARPA) is a research and development agency of the United States Department of Defense responsible for the development of emerging technologies for use by the military. Originally known as the Ad ...
and
Vint Cerf Vinton Gray Cerf (; born June 23, 1943) is an American Internet pioneer and is recognized as one of " the fathers of the Internet", sharing this title with TCP/IP The Internet protocol suite, commonly known as TCP/IP, is the set of commun ...

Vint Cerf
at
Stanford University Stanford University, officially Leland Stanford Junior University, is a private Private or privates may refer to: Music * "In Private "In Private" was the third single in a row to be a charting success for United Kingdom, British singer Du ...

Stanford University
and later DARPA led to the formulation of the Transmission Control Program, which incorporated concepts from the French
CYCLADES The CYCLADES computer network A computer network is a group of computers that use a set of common communication protocols over digital signal, digital interconnections for the purpose of sharing resources located on or provided by the Node (ne ...

CYCLADES
project directed by
Louis Pouzin Louis Pouzin (born 1931 in Chantenay-Saint-Imbert, Nièvre, France) is a French computer scientist. He designed an early packet-switched, packet communications network, CYCLADES. This network was the first actual implementation of the pure datagram ...

Louis Pouzin
. As this work progressed, a protocol was developed by which multiple separate networks could be joined into a network of networks. Version 4 of
TCP/IP The Internet protocol suite, commonly known as TCP/IP, is the set of communications protocol A communication protocol is a system of rules that allows two or more entities of a communications system 400px, Communication system A commu ...
was installed in the ARPANET for production use in January 1983 after the Department of Defense made it standard for all military computer networking. Access to the ARPANET was expanded in 1981, when the
National Science Foundation The National Science Foundation (NSF) is an independent agency of the United States government Independent or Independents may refer to: Arts, entertainment, and media Artist groups * Independents (artist group)The Independents were a group of ...

National Science Foundation
(NSF) funded the Computer Science Network (CSNET). In the early 1980s, the NSF funded the establishment of national supercomputing centers at several universities, and provided network access and network interconnectivity with the
NSFNET The National Science Foundation Network (NSFNET) was a program of coordinated, evolving projects sponsored by the National Science Foundation The National Science Foundation (NSF) is an independent agency of the United States government Indep ...
project in 1986. The ARPANET was formally decommissioned in 1990, after had assured private sector expansion and future commercialization of an expanded world-wide network, known as the
Internet The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a ''internetworking, network of networks'' that consist ...

Internet
.


History


Inspiration

Historically, voice and data communications were based on methods of
circuit switching Circuit switching is a method of implementing a telecommunications network A telecommunications network is a group of nodes In general, a node is a localized swelling (a "knot") or a point of intersection (a Vertex (graph theory), vertex). Nod ...
, 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 Paul Baran (born Pesach Baran ; April 29, 1926 – March 26, 2011) was a Polish-American engineer who was a pioneer in the development of computer networks. He was one of the two independent inventors of packet switching, which is today the domin ...
at the
RAND Corporation The RAND Corporation ("research and development") is an American nonprofit A nonprofit organization (NPO), also known as a non-business entity, not-for-profit organization, or nonprofit institution, is a legal entity organized and ope ...
, 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''. However, the telecommunication establishment rejected the development in favor of existing models.
Donald Davies Donald Watts Davies, (7 June 1924 – 28 May 2000) was a Welsh computer scientist A computer scientist is a person who has acquired the knowledge of computer science Computer science deals with the theoretical foundations of informati ...

Donald Davies
at the United Kingdom's National Physical Laboratory (NPL) independently arrived at a similar concept in 1965. The earliest ideas for a computer network intended to allow general communications among computer users were formulated by
computer scientist A computer scientist is a person who has acquired the knowledge of computer science, the study of the theoretical foundations of information and computation and their application. Computer scientists typically work on the theoretical side of c ...
of
Bolt, Beranek and Newman Raytheon BBN Technologies (originally Bolt Beranek and Newman Inc.) was an American research and development company, based next to Fresh Pond in Cambridge, Massachusetts Cambridge ( ) is a city in Middlesex County, Massachusetts, Middlesex C ...
(BBN), in April 1963, in memoranda discussing the concept of the " Intergalactic Computer Network". Those ideas encompassed many of the features of the contemporary Internet. In October 1963, Licklider was appointed head of the Behavioral Sciences and Command and Control programs at the Defense Department's
Advanced Research Projects Agency The Defense Advanced Research Projects Agency (DARPA) is a research and development agency of the United States Department of Defense The United States Department of Defense (DoD, USDOD or DOD) is an United States federal executive depart ...
(ARPA). He convinced
Ivan Sutherland Ivan Edward Sutherland (born May 16, 1938) is an American computer scientist A computer scientist is a person A person (plural people or persons) is a being that has certain capacities or attributes such as reason, morality, consciousness o ...
and Bob Taylor that this network concept was very important and merited development, although Licklider left ARPA before any contracts were assigned for development. 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 Computer science deals with the theoretical foundations of information, algorithms and the architectures of its computation as well as practical techniques for their application. Computer science is the study of computation, automation, a ...
results. Taylor had three computer terminals in his office, each connected to separate computers, which ARPA was funding: one for the
System Development Corporation System Development Corporation (SDC) was a computer software Software is a collection of Instruction (computer science), instructions and data (computing), data that tell a computer how to work. This is in contrast to Computer hardware, physic ...
(SDC) Q-32 in
Santa Monica Santa Monica () is a beachfront city in western Los Angeles County, California Los Angeles County, officially the County of Los Angeles, and sometimes abbreviated as L.A. County, is the List of the most populous counties in the United Stat ...

Santa Monica
, one for
Project Genie Project Genie was a computer research project started in 1964 at the University of California, Berkeley. It produced an early time-sharing system including the Berkeley Timesharing System, which was then commercialized as the SDS 940. History Proj ...
at the
University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public In public relations Public relations (PR) is the practice of managing and disseminating information from an individual or an organization ...

University of California, Berkeley
, and another for
Multics Multics ("Multiplexed Information and Computing Service") is an influential early time-sharing In computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experi ...

Multics
at the
Massachusetts Institute of Technology Massachusetts Institute of Technology (MIT) is a private Private or privates may refer to: Music * "In Private "In Private" was the third single in a row to be a charting success for United Kingdom, British singer Dusty Springfield, aft ...
. 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". Donald Davies' work caught the attention of ARPANET developers at
Symposium on Operating Systems PrinciplesThe Symposium on Operating Systems Principles (SOSP), organized by the Association for Computing Machinery The Association for Computing Machinery (ACM) is a US-based international learned society for computing. It was founded in 1947 and is the w ...
in October 1967. He gave the first public demonstration, having coined the term ''
packet switching In telecommunication Telecommunication is the transmission of information by various types of technologies over wire A wire is a single usually cylindrical A cylinder (from Greek Greek may refer to: Greece Anything of, from, or re ...
'', on 5 August 1968 and incorporated it into the
NPL network The NPL network, or NPL Data Communications Network, was a local area computer network A computer network is a set of s sharing resources located on or provided by . The computers use common s over to communicate with each other. These i ...
in England. The NPL network and ARPANET were the first two networks in the world to use packet switching,; and were themselves interconnected in 1973.(source: Gatlinburg, ... Association for Computing Machinery) Roberts said the ARPANET and other packet switching networks built in the 1970s were similar "in nearly all respects" to Davies' original 1965 design.


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. Taylor hired Larry Roberts as a program manager in the ARPA
Information Processing Techniques Office The Information Processing Techniques Office (IPTO), originally "Command and Control Research",Lyon, Matthew; Hafner, Katie (1999-08-19). ''Where Wizards Stay Up Late: The Origins Of The Internet'' (p. 39). Simon & Schuster. Kindle Edition. was part ...
in January 1967 to work on the ARPANET. Roberts asked
Frank WesterveltFranklin Herbert Westervelt ( – ) was an American engineer, computer scientist, and educator at the University of Michigan and Wayne State University. Westervelt received degrees in Mathematics, Mechanical and Electrical Engineering from the Co ...
to explore the initial design questions for a network."Planning the ARPANET: 1967-1968" in Chapter 2 on Networking: Vision and Packet Switching 1959-1968 Intergalactic Vision to Arpanet, ''Entrepreneurial Capitalism and Innovation: A History of Computer Communications 1968-1988''
James Pelkey, 2007
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. 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 Wesley Kanne Clark, Sr. (born December 23, 1944) is a retired general A general officer is an officer of high rank in the armies, and in some nations' air forces, space forces, or marines Marines or naval infantry, are typically a ...
proposed minicomputers should be used as an interface to create a
message switchingIn telecommunications Telecommunication is the transmission of information by various types of technologies over wire, radio, Optical system, optical, or other Electromagnetism, electromagnetic systems. It has its origin in the desire of humans ...
network. Roberts modified the ARPANET plan to incorporate Clark's suggestion and named the minicomputers
Interface Message Processor The Interface Message Processor (IMP) was the packet switching node (networking), node used to interconnect participant networks to the ARPANET from the late 1960s to 1989. It was the first generation of Gateway (telecommunications), gateways, whic ...
s (IMPs). The plan was presented at the inaugural
Symposium on Operating Systems PrinciplesThe Symposium on Operating Systems Principles (SOSP), organized by the Association for Computing Machinery The Association for Computing Machinery (ACM) is a US-based international learned society for computing. It was founded in 1947 and is the w ...
in October 1967.
Donald Davies Donald Watts Davies, (7 June 1924 – 28 May 2000) was a Welsh computer scientist A computer scientist is a person who has acquired the knowledge of computer science Computer science deals with the theoretical foundations of informati ...

Donald Davies
' work on packet switching and the
NPL network The NPL network, or NPL Data Communications Network, was a local area computer network A computer network is a set of s sharing resources located on or provided by . The computers use common s over to communicate with each other. These i ...
, presented by a colleague (
Roger Scantlebury Roger Anthony Scantlebury (born August 1936) is a British computer scientist who worked at the National Physical Laboratory (NPL) and later at Logica. Scantlebury participated in pioneering work to develop packet switching In telecommunications ...
), came to the attention of the ARPA investigators at this conference. Roberts applied Davies' concept of packet switching for the ARPANET, and sought input from
Paul Baran Paul Baran (born Pesach Baran ; April 29, 1926 – March 26, 2011) was a Polish-American engineer who was a pioneer in the development of computer networks. He was one of the two independent inventors of packet switching, which is today the domin ...
. 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. By mid-1968, Roberts and Barry Wessler wrote a final version of the IMP specification based on a
Stanford Research Institute SRI International (SRI) is an American nonprofit organization, nonprofit scientific research, scientific research institute and organization headquartered in Menlo Park, California. The trustees of Stanford University established SRI in 1946 as ...
(SRI) report that ARPA commissioned to write detailed specifications describing the ARPANET communications network. Roberts gave a report to Taylor on 3 June, who approved it on 21 June. After approval by ARPA, a
Request for Quotation A request for quotation (RfQ) is a business process in which a company or public entity requests a quote from a Distributor (business), supplier for the purchase of specific Product (business), products or Service (economics), services. RfQ general ...
(RFQ) was issued for 140 potential bidders. Most computer science companies regarded the ARPA proposal as outlandish, and only twelve submitted bids to build a network; of the twelve, ARPA regarded only four as top-rank contractors. At year's end, ARPA considered only two contractors, and awarded the contract to build the network to Bolt, Beranek and Newman Inc. (BBN) on 7 April 1969. 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. This team was led by Frank Heart and included Robert Kahn. The BBN-proposed network closely followed Roberts' ARPA plan: a network composed of small computers called
Interface Message Processor The Interface Message Processor (IMP) was the packet switching node (networking), node used to interconnect participant networks to the ARPANET from the late 1960s to 1989. It was the first generation of Gateway (telecommunications), gateways, whic ...
s (or IMPs), similar to the later concept of routers, that functioned as gateways interconnecting local resources. At each site, the IMPs performed store-and-forward packet switching functions, and were interconnected with
leased line A leased line is a private telecommunications circuit A telecommunication circuit is a path in a telecommunications network used to Transmission (telecommunications), transmit information. Definitions A telecommunication circuit may be define ...
s via telecommunication data sets (
modem A modulator-demodulator, or simply a modem, is a hardware device that converts data from a digital format, intended for communication directly between devices with specialized wiring, into one suitable for a transmission medium such as telep ...

modem
s), with initial data rates of . The host computers were connected to the IMPs via custom
serial communication In telecommunication Telecommunication is the transmission of information by various types of technologies over wire A wire is a single usually cylindrical A cylinder (from Greek Greek may refer to: Greece Anything of, from, or r ...

serial communication
interfaces. The system, including the hardware and the packet switching software, was designed and installed in nine months. The BBN team continued to interact with the NPL team with meetings between them taking place in the U.S. and the U.K. The first-generation IMPs were built by BBN Technologies using a
rugged computer A rugged, or ruggedized computer is a computer A computer is a machine that can be programmed to Execution (computing), carry out sequences of arithmetic or logical operations automatically. Modern computers can perform generic sets of operat ...
version of the
Honeywell Honeywell International Inc. is an American public company, publicly traded, multinational corporation, multinational conglomerate (company), conglomerate corporation headquartered in Charlotte, North Carolina. It primarily operates in four are ...

Honeywell
DDP-516 The Honeywell 316 was a popular built by starting in 1969. It is part of the Series 16, which includes the Models 116 (1965, ), 316 (1969), 416 (1966), 516 (1966) and DDP-716 (1969). They were commonly used for data acquisition and control, rem ...
computer, configured with of expandable
magnetic-core memory Magnetic-core memory was the predominant form of random-access Random access (more precisely and more generally called direct access) is the ability to access an arbitrary element of a sequence in equal time or any datum from a population of ...
, and a 16-channel Direct Multiplex Control (DMC)
direct memory access Direct memory access (DMA) is a feature of computer systems that allows certain hardware subsystems to access main system memory Memory is the faculty of the by which or is , stored, and retrieved when needed. It is the retention of inform ...
unit. The DMC established custom interfaces with each of the host computers and modems. In addition to the front-panel lamps, the DDP-516 computer also features a special set of 24 indicator lamps showing the status of the IMP communication channels. Each IMP could support up to four local hosts, and could communicate with up to six remote IMPs via early
Digital Signal 0 Digital Signal 0 (DS0) is a basic digital signaling rate of 64 kilobits per second (kbit/s In telecommunications Telecommunication is the transmission of information by various types of technologies over , radio, , or other systems. It ha ...
leased telephone lines. The network connected one computer in Utah with three in California. Later, the Department of Defense allowed the universities to join the network for sharing hardware and software resources.


Debate on design goals

According to Charles Herzfeld, ARPA Director (1965–1967): Nonetheless, according to Stephen J. Lukasik, who as Deputy Director and Director of DARPA (1967–1974) was "the person who signed most of the checks for Arpanet's development": The ARPANET incorporated distributed computation, and frequent re-computation, of routing tables. This increased the survivability of the network in the face of significant interruption. Automatic routing was technically challenging at the time. The ARPANET was designed to survive subordinate-network losses, since the principal reason was that the switching nodes and network links were unreliable, even without any nuclear attacks. The
Internet Society The Internet Society (ISOC) is an American nonprofit organization A nonprofit organization (NPO), also known as a non-business entity, not-for-profit organization, or nonprofit institution, is a legal entity organized and operated for a col ...
agrees with Herzfeld in a footnote in their online article, ''A Brief History of the Internet'':
Paul Baran Paul Baran (born Pesach Baran ; April 29, 1926 – March 26, 2011) was a Polish-American engineer who was a pioneer in the development of computer networks. He was one of the two independent inventors of packet switching, which is today the domin ...
, the first to put forward a theoretical model for communication using packet switching, conducted the
RAND The RAND Corporation ("research and development") is an American nonprofit A nonprofit organization (NPO), also known as a non-business entity, not-for-profit organization, or nonprofit institution, is a legal entity organized and ope ...
study referenced above. Though the ARPANET did not exactly share Baran's project's goal, he said his work did contribute to the development of the ARPANET. Minutes taken by Elmer Shapiro of
Stanford Research Institute SRI International (SRI) is an American nonprofit organization, nonprofit scientific research, scientific research institute and organization headquartered in Menlo Park, California. The trustees of Stanford University established SRI in 1946 as ...
at the ARPANET design meeting of 9–10 October 1967 indicate that a version of Baran's routing method ("hot potato") may be used, consistent with the NPL team's proposal at the Symposium on Operating System Principles in Gatlinburg.


Implementation

The first four nodes were designated as a testbed for developing and debugging the 1822 protocol, which was a major undertaking. While they were connected electronically in 1969, network applications were not possible until the
Network Control Program The Network Control Program (NCP) provided the middle layers of the protocol stack running on host computers of the ARPANET, the predecessor to the modern Internet The Internet (Capitalization of Internet, or internet) is the global ...
was implemented in 1970 enabling the first two host-host protocols, remote login (
Telnet Telnet is an application protocol used on the Internet The Internet (or internet) is the global system of interconnected s that uses the (TCP/IP) to communicate between networks and devices. It is a ' that consists of private, publ ...
) and file transfer (
FTP The File Transfer Protocol (FTP) is a standard communication protocol used for the transfer of computer files from a server to a client on a computer network. FTP is built on a client–server model architecture using separate control and data c ...
) which were specified and implemented between 1969 and 1973. Network traffic began to grow once
email upThe email_address.html"_;"title="at_sign,_a_part_of_every_SMTP_email_address">at_sign,_a_part_of_every_SMTP_email_address Electronic_mail_(email_or_e-mail)_is_a_method_of_exchanging_messages_("mail")_between_people_using_electronic_dev ...

email
was established at the majority of sites by around 1973.


Initial four hosts

The first four IMPs were: *
University of California, Los Angeles The University of California, Los Angeles (UCLA) is a public university, public Land-grant university, land-grant research university in Los Angeles, California. UCLA’s academic roots were established in 1882 as a teachers college then known ...
(UCLA), where
Leonard Kleinrock Leonard Kleinrock (born June 13, 1934) is an American computer scientist. A professor at UCLA's Henry Samueli School of Engineering and Applied Science, he made several important contributions to the field of computer science, in particular to ...
had established a Network Measurement Center, with an SDS Sigma 7 being the first computer attached to it; * The
Augmentation Research Center SRI International's Augmentation Research Center (ARC) was founded in the 1960s by electrical engineer Douglas Engelbart to develop and experiment with new tools and techniques for collaboration and information processing Information processing ...
at Stanford Research Institute (now
SRI International SRI International (SRI) is an American nonprofit organization, nonprofit scientific research, scientific research institute and organization headquartered in Menlo Park, California. The trustees of Stanford University established SRI in 1946 as ...
), where
Douglas Engelbart Douglas Carl Engelbart (January 30, 1925 â€“ July 2, 2013) was an engineer Engineers, as practitioners of engineering, are Professional, professionals who Invention, invent, design, analyze, build and test Machine, machines, complex sys ...
had created the new NLS system, an early
hypertext Hypertext is text displayed on a computer display A computer monitor is an output device that displays information in pictorial or text form. A monitor usually comprises a electronic visual display, visual display, electronic circuit, ...

hypertext
system, and would run the Network Information Center (NIC), with the
SDS 940 The SDS 940 was Scientific Data Systems' (SDS) first machine designed to directly support time-sharing In computing, time-sharing is the sharing of a computing resource among many users at the same time by means of multiprogramming and computer ...
that ran NLS, named "Genie", being the first host attached; *
University of California, Santa Barbara The University of California, Santa Barbara (UC Santa Barbara or UCSB) is a Public university, public Land-grant university, land-grant research university in Santa Barbara, California, Santa Barbara-Isla Vista, California. It is part of the Uni ...
(UCSB), with the Culler-Fried Interactive Mathematics Center's
IBM International Business Machines Corporation (IBM) is an American multinational technology company headquartered in Armonk, New York, with operations in over 170 countries. The company began in 1911, founded in Endicott, New York, as the C ...

IBM
360/75, running OS/MVT being the machine attached; * The University of Utah School of Computing, where
Ivan Sutherland Ivan Edward Sutherland (born May 16, 1938) is an American computer scientist A computer scientist is a person A person (plural people or persons) is a being that has certain capacities or attributes such as reason, morality, consciousness o ...
had moved, running a DEC
PDP-10 Digital Equipment Corporation Digital Equipment Corporation (DEC ), using the Digital, was a major American company in the from the 1960s to the 1990s. The company was co-founded by and in 1957. Olsen was president until forced to resi ...
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). Kline connected from UCLA's
SDS Sigma 7 The SDS Sigma series is a series of third generation computers that were introduced by Scientific Data Systems of the United States in 1966. The first machines in the series are the 16-bit Sigma 2 and the 32-bit Sigma 7; the Sigma 7 was the first 3 ...
Host computer (in Boelter Hall room 3420) to the Stanford Research Institute's
SDS 940 The SDS 940 was Scientific Data Systems' (SDS) first machine designed to directly support time-sharing In computing, time-sharing is the sharing of a computing resource among many users at the same time by means of multiprogramming and computer ...
Host computer. Kline typed the command "login," but initially the SDS 940 crashed after he typed two characters. About an hour later, after Duvall adjusted parameters on the machine, Kline tried again and successfully logged in. Hence, the first two characters successfully transmitted over the ARPANET were "lo". The first permanent ARPANET link was established on 21 November 1969, between the IMP at UCLA and the IMP at the Stanford Research Institute. By 5 December 1969, the initial four-node network was established.
Elizabeth Feinler Elizabeth Jocelyn "Jake" Feinler (born March 2, 1931) is an American information scientist. From 1972 until 1989 she was director of the Network Information Systems Center at the Stanford Research Institute SRI International (SRI) is an Americ ...
created the first Resource Handbook for ARPANET in 1969 which led to the development of the ARPANET directory. The directory, built by Feinler and a team made it possible to navigate the ARPANET.


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. By March 1970, the ARPANET reached the East Coast of the United States, when an
IMP An imp is a European European, or Europeans, may refer to: In general * ''European'', an adjective referring to something of, from, or related to Europe ** Ethnic groups in Europe ** Demographics of Europe ** European cuisine, the cuisines of E ...
at BBN in
Cambridge, Massachusetts Cambridge ( ) is a city in Middlesex County, Massachusetts, Middlesex County, Massachusetts, and part of the Greater Boston, Boston metropolitan area as a major suburb of Boston. , it was the fifth most populous city in the state, behind Boston, ...
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. Larry Roberts saw the ARPANET and NPL projects as complementary and sought in 1970 to connect them via a satellite link. Peter Kirstein's research group at
University College London University College London, which Trade name, operates as UCL, is a major public university , public research university located in London, United Kingdom. UCL is a Member institutions of the University of London, member institution of the Federa ...
(UCL) was subsequently chosen in 1971 in place of NPL for the UK connection. In June 1973, a transatlantic satellite link connected ARPANET to the (NORSAR), via the Tanum Earth Station in Sweden, and onward via a terrestrial circuit to a TIP at UCL. UCL provided a gateway for an interconnection with the
NPL network The NPL network, or NPL Data Communications Network, was a local area computer network A computer network is a set of s sharing resources located on or provided by . The computers use common s over to communicate with each other. These i ...
, the first interconnected network, and subsequently the SRCnet, the forerunner of UK's
JANET Janet may refer to: Names * Janet (given name) Janet is a feminine given name Image:FML names-2.png, Diagram of naming conventions, using John F. Kennedy as an example. "First names" can also be called given names; "last names" can also be ca ...
network.


Network performance

In 1968, Roberts contracted with Kleinrock to measure the performance of the network and find areas for improvement. Building on his earlier work on
queueing theory Queueing theory is the mathematical study of waiting lines, or . A queueing model is constructed so that queue lengths and waiting time can be predicted. Queueing theory is generally considered a branch of because the results are often used whe ...
, 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.


Operation

The ARPANET was a research project that was communications-oriented, rather than user-oriented in design. Nonetheless, in the summer of 1975, the ARPANET was declared "operational". The
Defense Communications Agency The Defense Information Systems Agency (DISA), known as the Defense Communications Agency (DCA) until 1991, is a United States Department of Defense The United States Department of Defense (DoD, USDOD or DOD) is an United States federal exec ...
took control since ARPA was intended to fund advanced research. At about this time, the first
ARPANET encryption devices The ARPANET pioneered the creation of novel encryption devices for packet networks in the 1970s and 1980s, and as such were ancestors to today's IPsec architecture, and High Assurance Internet Protocol Encryptor (HAIPE) devices more specifically. ...
were deployed to support classified traffic. The transatlantic connectivity with NORSAR and UCL later evolved into the
SATNET SATNET, also known as the Atlantic Packet Satellite Network, was an early satellite network that formed an initial segment of the Internet The Internet (Capitalization of Internet, or internet) is the global system of interconnected ...
. The ARPANET, SATNET and
PRNET The Packet Radio Network (PRNET) was a set of early, experimental mobile ad hoc network A wireless ad hoc network (WANET) or mobile ad hoc network (MANET) is a decentralized type of wireless network A wireless network is a computer network ...
were interconnected in 1977. The ''ARPANET Completion Report'', published in 1981 jointly by BBN and ARPA, concludes that:


CSNET, expansion

Access to the ARPANET was expanded in 1981, when the
National Science Foundation The National Science Foundation (NSF) is an independent agency of the United States government Independent or Independents may refer to: Arts, entertainment, and media Artist groups * Independents (artist group)The Independents were a group of ...

National Science Foundation
(NSF) funded the Computer Science Network (CSNET).


Adoption of TCP/IP

NORSAR and University College London left the ARPANET and began using
TCP/IP The Internet protocol suite, commonly known as TCP/IP, is the set of communications protocol A communication protocol is a system of rules that allows two or more entities of a communications system 400px, Communication system A commu ...
over SATNET in early 1982. After the DoD made TCP/IP standard for all military computer networking. On January 1, 1983, known as
flag day A flag day is a flag A flag is a piece of textile, fabric (most often rectangular or quadrilateral) with a distinctive design and colours. It is used as a symbol, a signalling device, or for decoration. The term ''flag'' is also used to refe ...
, TCP/IP protocols became the standard for the ARPANET, replacing the earlier
Network Control Program The Network Control Program (NCP) provided the middle layers of the protocol stack running on host computers of the ARPANET, the predecessor to the modern Internet The Internet (Capitalization of Internet, or internet) is the global ...
.


MILNET, phasing out

In September 1984 work was completed on restructuring the ARPANET giving U.S. military sites their own Military Network (
MILNET In computer networking, MILNET (fully Military Network) was the name given to the part of the designated for unclassified traffic.DEFENSE DATA NETWORK NEWSLETTEDDN-NEWS 26 6 May 1983 MILNET was physically separated from the ARPANET in 1983. T ...
) for unclassified defense department communications. 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 The Defense Data Network (DDN) was a computer network A computer network is a set of s sharing resources located on or provided by . The computers use common s over to communicate with each other. These interconnections are made up of tech ...
(DDN). Separating the civil and military networks reduced the 113-node ARPANET by 68 nodes. After MILNET was split away, the ARPANET would continue be used as an Internet backbone for researchers, but be slowly phased out.


Decommissioning

In 1985, the
National Science Foundation The National Science Foundation (NSF) is an independent agency of the United States government Independent or Independents may refer to: Arts, entertainment, and media Artist groups * Independents (artist group)The Independents were a group of ...

National Science Foundation
(NSF) funded the establishment of national supercomputing centers at several universities, and provided network access and network interconnectivity with the
NSFNET The National Science Foundation Network (NSFNET) was a program of coordinated, evolving projects sponsored by the National Science Foundation The National Science Foundation (NSF) is an independent agency of the United States government Indep ...
project in 1986. NSFNET became the Internet backbone for government agencies and universities. 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. In the wake of the decommissioning of the ARPANET on 28 February 1990, Vinton Cerf wrote the following lamentation, entitled "Requiem of the ARPANET":


Legacy

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
Al Gore Albert Arnold Gore Jr. (born March 31, 1948) is an American politician and environmentalist who served as the 45th vice president of the United States from 1993 to 2001. Gore was Bill Clinton's running mate in their Bill Clinton presidential ...

Al Gore
authored the
High Performance Computing and Communication Act of 1991 The High Performance Computing Act of 1991 (HPCA) is an Act of Congress promulgation, promulgated in the 102nd United States Congress as (Pub.L. 102–194) on December 9, 1991. Often referred to as the Gore Bill, it was created and introduced by the ...
, commonly referred to as "The Gore Bill", after hearing the 1988 concept for a National Research Network submitted to Congress by a group chaired by
Leonard Kleinrock Leonard Kleinrock (born June 13, 1934) is an American computer scientist. A professor at UCLA's Henry Samueli School of Engineering and Applied Science, he made several important contributions to the field of computer science, in particular to ...
. The bill was passed on 9 December 1991 and led to the National Information Infrastructure (NII) which Gore called the ''information superhighway''. Inter-networking protocols developed by ARPA and implemented on the ARPANET paved the way for future commercialization of a new world-wide network, known as the
Internet The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a ''internetworking, network of networks'' that consist ...

Internet
. The ARPANET project was honored with two List of IEEE milestones, IEEE Milestones, both dedicated in 2009.


Software and protocols


1822 protocol

The starting point for host-to-host communication on the ARPANET in 1969 was the 1822 protocol, which defined the transmission of messages to an IMP. The message format was designed to work unambiguously with a broad range of computer architectures. An 1822 message essentially consisted of a message type, a numeric host address, and a data field. To send a data message to another host, the transmitting host formatted a data message containing the destination host's address and the data message being sent, and then transmitted the message through the 1822 hardware interface. The IMP then delivered the message to its destination address, either by delivering it to a locally connected host, or by delivering it to another IMP. When the message was ultimately delivered to the destination host, the receiving IMP would transmit a ''Ready for Next Message'' (RFNM) acknowledgement to the sending, host IMP.


Network Control Program

Unlike modern Internet datagrams, the ARPANET was designed to reliably transmit 1822 messages, and to inform the host computer when it loses a message; the contemporary Internet Protocol#Reliability, IP is unreliable, whereas the Transmission Control Protocol, TCP is reliable. Nonetheless, the 1822 protocol proved inadequate for handling multiple connections among different applications residing in a host computer. This problem was addressed with the
Network Control Program The Network Control Program (NCP) provided the middle layers of the protocol stack running on host computers of the ARPANET, the predecessor to the modern Internet The Internet (Capitalization of Internet, or internet) is the global ...
(NCP), which provided a standard method to establish reliable, flow-controlled, bidirectional communications links among different processes in different host computers. The NCP interface allowed application software to connect across the ARPANET by implementing higher-level communication protocols, an early example of the ''protocol layering'' concept later incorporated in the OSI model. NCP was developed under the leadership of Stephen D. 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 sponsored by ARPA to carry out the development of the ARPANET and the software for the host computers that supported applications. The various application protocols such as TELNET for remote time-sharing access, File Transfer Protocol (FTP) and rudimentary electronic mail protocols were developed and eventually ported to run over the TCP/IP protocol suite or replaced in the case of email by the Simple Mail Transport Protocol.


TCP/IP

Steve Crocker formed a "Networking Working Group" with
Vint Cerf Vinton Gray Cerf (; born June 23, 1943) is an American Internet pioneer and is recognized as one of " the fathers of the Internet", sharing this title with TCP/IP The Internet protocol suite, commonly known as TCP/IP, is the set of commun ...

Vint Cerf
who also joined an International Networking Working Group in the early 1970s. These groups considered how to interconnect packet switching networks with different specifications, that is, internetworking. Research led by
Bob Kahn Robert Elliot Kahn (born December 23, 1938) is an American electrical engineer Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems which use electricity, e ...

Bob Kahn
at DARPA and Vint Cerf at
Stanford University Stanford University, officially Leland Stanford Junior University, is a private Private or privates may refer to: Music * "In Private "In Private" was the third single in a row to be a charting success for United Kingdom, British singer Du ...

Stanford University
and later DARPA resulted in the formulation of the Transmission Control Program, with its specification written by Cerf with Yogen Dalal and Carl Sunshine in December 1974. The following year, testing began through concurrent implementations at Stanford, BBN and
University College London University College London, which Trade name, operates as UCL, is a major public university , public research university located in London, United Kingdom. UCL is a Member institutions of the University of London, member institution of the Federa ...
. At first a monolithic design, the software was redesigned as a modular protocol stack in version 3 in 1978. IPv4, Version 4 was installed in the ARPANET for production use in January 1983, replacing NCP. The development of the complete Internet protocol suite by 1989, as outlined in and , and laid the foundation for the adoption of TCP/IP as a comprehensive protocol suite as the core component of the emerging
Internet The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a ''internetworking, network of networks'' that consist ...

Internet
.


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.
Telnet Telnet is an application protocol used on the Internet The Internet (or internet) is the global system of interconnected s that uses the (TCP/IP) to communicate between networks and devices. It is a ' that consists of private, publ ...
was developed in 1969 beginning with RFC 15, extended in RFC 855. The original specification for the File Transfer Protocol was written by Abhay Bhushan and published as on 16 April 1971. By 1973, the File Transfer Protocol (FTP) specification had been defined () and implemented, enabling file transfers over the ARPANET. In 1971, Ray Tomlinson, of Bolt, Beranek and Newman, BBN sent the first network e-mail (, ). Within a few years, e-mail came to represent a very large part of the overall ARPANET traffic. The Network Voice Protocol (NVP) specifications were defined in 1977 (), and implemented. But, because of technical shortcomings, conference calls over the ARPANET never worked well; the contemporary Voice over Internet Protocol (packet voice) was decades away.


Password protection

The George B. Purdy#The Purdy Polynomial, 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 OpenVMS, VMS operating system and is still being used for this purpose.


Technology

Support for inter-IMP circuits of up to 230.4 kbit/s was added in 1970, although considerations of cost and
IMP An imp is a European European, or Europeans, may refer to: In general * ''European'', an adjective referring to something of, from, or related to Europe ** Ethnic groups in Europe ** Demographics of Europe ** European cuisine, the cuisines of E ...
processing power meant this capability was not actively used. 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. 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. In 1975, BBN introduced IMP software running on the Pluribus multi-processor. These appeared in a few sites. In 1981, BBN introduced
IMP An imp is a European European, or Europeans, may refer to: In general * ''European'', an adjective referring to something of, from, or related to Europe ** Ethnic groups in Europe ** Demographics of Europe ** European cuisine, the cuisines of E ...
software running on its own C/30 processor product.


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. In 1978, against the rules of the network, Gary Thuerk of Digital Equipment Corporation (DEC) sent out the first mass email to approximately 400 potential clients via the ARPANET. He claims that this resulted in $13 million worth of sales in DEC products, and highlighted the potential of email marketing. A 1982 handbook on computing at MIT's AI Lab stated regarding network etiquette:


In popular culture

* ''Computer Networks: The Heralds of Resource Sharing'', a 30-minute documentary film featuring Fernando J. Corbató, , Lawrence G. Roberts, Bob Kahn, Robert Kahn, Frank Heart, William R. Sutherland, Richard W. Watson, John R. Pasta, Donald W. Davies, and economist, George W. Mitchell (economist), George W. Mitchell. * List of Benson episodes#Season 6: 1984–85, "Scenario", an episode of the U.S. television sitcom Benson (TV series), ''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. * There is an electronic music artist known as "Arpanet", Gerald Donald, one of the members of Drexciya. The artist's 2002 album ''Wireless Internet'' features commentary on the expansion of the internet via wireless communication, with songs such as ''NTT DoCoMo'', dedicated to the mobile communications giant based in Japan. * 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''. * The 1993 television series ''The X-Files'' featured the ARPANET in a season 5 episode, titled "Unusual Suspects (The X-Files), Unusual Suspects". John Fitzgerald Byers offers to help Susan Modeski (known as Holly ... "just like the sugar") by hacking into the ARPANET to obtain sensitive information. * 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 (TV series), Person of Interest'', main character Harold Finch (Person of Interest), Harold Finch hacked the ARPANET in 1980 using a homemade computer during his first efforts to build a prototype of the Machine. This corresponds with the real life virus that occurred in October of that year that temporarily halted ARPANET functions. The ARPANET hack was first discussed in the episode List of Person of Interest episodes#ep34, ''2PiR'' (stylised ''2\piR'') 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 (TV series), Halt and Catch Fire'', the character Joe MacMillan explores the potential commercialization of the ARPANET.


See also

* .arpa, a 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 * Usenet, "A Poor Man's ARPAnet" * OGAS


References


Sources

*


Further reading

* * * * * * * *


Oral histories

* Focuses on Kahn's role in the development of computer networking from 1967 through the early 1980s. Beginning with his work at Bolt Beranek and Newman (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 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 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 discusses his work on the ARPANET. * * Lukasik discusses his tenure at the Advanced Research Projects Agency (ARPA), the development of computer networks and the ARPANET. * Frank describes his work on the ARPANET, including his interaction with Roberts and the IPT Office.


Detailed technical reference works

* * * * * * * * * * * * * * ** NTIS documents may be available from * *


External links

* * * Timeline. * * Personal anecdote of the first message ever sent over the ARPANET * * * {{DEFAULTSORT:Arpanet ARPANET, American inventions History of the Internet Computer-related introductions in 1969 Internet properties established in 1969 Internet properties disestablished in 1990 1969 establishments in the United States Internet in the United States 1990 disestablishments in the United States