ARPANET: Difference between revisions

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.<ref>Markoff, John, Innovator who helped create PC, Internet and the mouse, New York Times, 15 April 2017, p.A1</ref> Taylor hired [[Lawrence Roberts (scientist)|Larry Roberts]] as a program manager in the ARPA [[Information Processing Techniques Office]] in January 1967 to work on the ARPANET.<ref name=":24">{{cite web |last=Pelkey |first=James |title=4.7 Planning the ARPANET: 1967-1968 in Chapter 4 - Networking: Vision and Packet Switching 1959 - 1968 |url=https://historyofcomputercommunications.info/section/4.7/planning-the-arpanet-1967-1968/ |url-status=dead |archive-url=https://web.archive.org/web/20221223230647/https://historyofcomputercommunications.info/section/4.7/planning-the-arpanet-1967-1968/ |archive-date=December 23, 2022 |access-date=May 9, 2023 |work=The History of Computer Communications}}</ref> Roberts met Paul Baran in February 1967, but did not discuss networks.<ref name=":5c">{{Cite book |last=Waldrop |first=M. Mitchell |url=https://books.google.com/books?id=eRnBEAAAQBAJ&pg=PT285 |title=The Dream Machine |date=2018 |publisher=Stripe Press |isbn=978-1-953953-36-0 |pages=285–6 |language=en |quote=Oops. Roberts knew Baran slightly and had in fact had lunch with him during a visit to RAND the previous February. But he certainly didn't remember any discussion of networks. How could he have missed something like that?}}</ref><ref>{{Cite web |last=O'Neill |first=Judy |date=5 March 1990 |title=An Interview with PAUL BARAN |url=https://conservancy.umn.edu/bitstream/handle/11299/107101/oh182pb.pdf?sequence=1&isAllowed=y |page=37 |quote=On Tuesday, 28 February 1967 I find a notation on my calendar for 12:00 noon Dr. L. Roberts.}}</ref>

 

 

The plan was presented at the inaugural Symposium on Operating Systems Principles in October 1967.<ref>{{Cite book|last=Roberts|first=Lawrence|date=1967|title=Multiple Computer Networks and Intercomputer Communications|chapter=Multiple computer networks and intercomputer communication|chapter-url=https://people.mpi-sws.org/~gummadi/teaching/sp07/sys_seminar/arpanet.pdf|pages=3.1–3.6|doi=10.1145/800001.811680|s2cid=17409102|quote=Thus the set of IMP's, plus the telephone lines and data sets would constitute a message switching network}}</ref> Donald Davies' work on packet switching and the NPL network, presented by a colleague ([[Roger Scantlebury]]), and that of Paul Baran, came to the attention of the ARPA investigators at this conference.<ref name="Gillies2000">{{cite book|last1=Gillies|first1=James|last2=Cailliau|first2=Robert|title=How the Web was Born: The Story of the World Wide Web|date=2000|publisher=Oxford University Press|isbn=978-0-19-286207-5|page=25|url=https://books.google.com/books?id=pIH-JijUNS0C&pg=PA25}}</ref><ref name="Isaacson2014">{{cite book|last1=Isaacson|first1=Walter|title=The Innovators: How a Group of Hackers, Geniuses, and Geeks Created the Digital Revolution|date=2014|publisher=Simon & Schuster|isbn=978-1-4767-0869-0|page=237|url=https://books.google.com/books?id=4V9koAEACAAJ&pg=PA237}}</ref> Roberts applied Davies' concept of packet switching for the ARPANET,<ref>{{cite web|title=Inductee Details – Donald Watts Davies|url=http://www.invent.org/honor/inductees/inductee-detail/?IID=328|publisher=National Inventors Hall of Fame|access-date=6 September 2017|archive-url=https://web.archive.org/web/20170906091936/http://www.invent.org/honor/inductees/inductee-detail/?IID=328|archive-date=6 September 2017|url-status=dead}}</ref><ref name="MCK">{{cite journal|first=Martin|last=Cambell-Kelly |title=Pioneer Profiles: Donald Davies|journal=Computer Resurrection|number=44|date=Autumn 2008|issn=0958-7403|url=http://www.computerconservationsociety.org/resurrection/res44.htm}}</ref> and sought input from Paul Baran on dynamic routing.<ref name="Abbate20002">{{cite book|last1=Abbate|first1=Janet|author-link=Janet Abbate|url=https://books.google.com/books?id=9BfZxFZpElwC&pg=PA37|title=Inventing the Internet|date=2000|publisher=[[MIT Press]]|isbn=978-0-2625-1115-5 |location=Cambridge, MA|pages=37–38, 58–59}}</ref> The NPL network was using line speeds of 768&nbsp;kbit/s, and the proposed line speed for the ARPANET was upgraded from 2.4&nbsp;kbit/s to 50&nbsp;kbit/s.<ref name="brief">{{cite web|title=Brief History of the Internet|url=http://www.internetsociety.org/internet/what-internet/history-internet/brief-history-internet#f5|publisher=Internet Society|access-date=12 July 2017}}</ref>

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]]; the theoretical design of the network was led by [[Bob Kahn]]; the team included [[David Walden|Dave Walden]], [[Severo Ornstein]], [[William Crowther (programmer)|William Crowther]] and several others.<ref name=":23">{{cite journal |last=Roberts |first=Lawrence G. |date=November 1978 |title=The evolution of packet switching |url=http://www.ece.ucf.edu/~yuksem/teaching/nae/reading/1978-roberts.pdf |journal=Proceedings of the IEEE |volume=66 |issue=11 |pages=1307–13 |doi=10.1109/PROC.1978.11141 |s2cid=26876676 |quote=Significant aspects of the network's internal operation, such as routing, flow control, software design, and network control were developed by a BBN team consisting of Frank Heart, Robert Kahn, Severo Omstein, William Crowther, and David Walden}}</ref><ref>{{Cite news|last=Hafner|first=Katie|url=https://www.nytimes.com/2018/06/25/technology/frank-heart-who-linked-computers-before-the-internet-dies-at-89.html|title=Frank Heart, Who Linked Computers Before the Internet, Dies at 89|date=2018-06-25|work=The New York Times|access-date=2020-04-03|language=en-US|issn=0362-4331}}</ref><ref name="Hafner1">{{harvnb|Hafner|Lyon|1996|pp=[https://archive.org/details/wherewizardsstay00haf_vgj/page/116/mode/2up?q=kahn 116, 149]}}</ref> The BBN-proposed network closely followed Roberts' ARPA plan: a network composed of small computers, the IMPs (similar to the later concept of [[Router (computing)|routers]]), that functioned as gateways interconnecting local resources. Routing, flow control, software design and network control were developed by the BBN team.<ref name=":23" /><ref name="F.E. Froehlich, A. Kent">{{cite book |author=F.E. Froehlich, A. Kent |url=https://books.google.com/books?id=gaRBTHdUKmgC&pg=PA344 |title=The Froehlich/Kent Encyclopedia of Telecommunications: Volume 1 - Access Charges in the U.S.A. to Basics of Digital Communications |date=1990 |publisher=CRC Press |isbn=0824729005 |page=344 |quote=Although there was considerable technical interchange between the NPL group and those who designed and implemented the ARPANET, the NPL Data Network effort appears to have had little fundamental impact on the design of ARPANET. Such major aspects of the NPL Data Network design as the standard network interface, the routing algorithm, and the software structure of the switching node were largely ignored by the ARPANET designers. There is no doubt, however, that in many less fundamental ways the NPL Data Network had and effect on the design and evolution of the ARPANET.}}</ref> At each site, the IMPs performed store-and-forward packet switching functions and were interconnected with [[leased line]]s via telecommunication data sets ([[modem]]s), with initial data rates of {{gaps|50|[[kilobit|kbit]]/s}}.<ref name="brief" /><ref>{{cite book |url=https://archive.org/details/DTIC_ADA096798 |title=ARPANET Information Brochure |date=May 1980 |page=12 |quote=The complete network is formed by interconnecting the nodes through wideband communication lines, normally 50,000 bits per second (50KBPS), supplied by common carriers}}</ref><ref>{{cite report | title=BBN Report No. 1928| date=January 1970| url=http://bärwolff.de/bbn-arpanet-reports-collection/BBN%20(1970)%20Interface%20Message%20Processors%20for%20the%20ARPA%20Computer%20Network%20(Report%201928,%20Quarterly%20Technical%20Report%204).pdf| quote=we designed and implemented a test program to obtain data on the performance of the fifty kilobit communication circuits}}</ref> 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.<ref name="Roberts1978"/><ref name="LivingInternetIMP"/><ref>{{cite web|title=Looking back at the ARPANET effort, 34 years later|url=https://www.livinginternet.com/internet/i/ii_imp_walden.htm|access-date=2021-03-19|date=February 2003}}</ref> The BBN team continued to interact with the NPL team with meetings between them taking place in the U.S. and the U.K.<ref name="Abbate2000">{{cite book|last1=Abbate|first1=Janet|title=Inventing the Internet|date=2000|location=Cambridge, MA|publisher=[[MIT Press]]|isbn=978-0-2625-1115-5|page=38|url=https://books.google.com/books?id=9BfZxFZpElwC&pg=PA38}}</ref><ref>{{cite conference |first1=Frank |last1=Heart |author-link2=Bob Kahn |first2=Robert |last2=Kahn |first3=Severo |last3=Ornstein |author-link3=Severo Ornstein |first4=William |last4=Crowther |author-link4=William Crowther (programmer) |first5=David |last5=Walden |title=Proceedings of the May 5-7, 1970, spring joint computer conference on - AFIPS '70 (Spring) |chapter=The Interface Message Processor for the ARPA Computer Network |chapter-url=http://www.walden-family.com/public/1970-imp-afips.pdf |conference=1970 Spring Joint Computer Conference |page=565 |year=1970 |doi=10.1145/1476936.1477021|s2cid=9647377 }}</ref><ref>{{cite journal |last1=Barber |first1=Derek |date=Spring 1993 |title=The Origins of Packet Switching |url=http://www.cs.man.ac.uk/CCS/res/res05.htm#f |journal=The Bulletin of the Computer Conservation Society |issue=5 |issn=0958-7403 |access-date=6 September 2017}}</ref>

 

 

==== Debate about design goals ====