Editing Internet protocol suite (section)

===Early research===
[[File:SRI First Internetworked Connection diagram.jpg|thumb|right|Diagram of the first internetworked connection]]
[[File:SRI Packet Radio Van.jpg|thumb|right|An [[SRI International]] [[Packet Radio Van]], used for the first three-way [[internetworked]] transmission]]
Initially referred to as the ''DOD Internet Architecture Model'', the Internet protocol suite has its roots in research and development sponsored by the Defense Advanced Research Projects Agency ([[DARPA]]) in the late 1960s.<ref name="Cerf DoD">{{cite journal|title=The DoD Internet Architecture Model|first1=Vinton G.|last1=Cerf|first2=Edward|last2=Cain|name-list-style=amp|journal=Computer Networks|volume=7|issue=5|date=October 1983|publisher=North-Holland|doi=10.1016/0376-5075(83)90042-9|pages=307–318}}</ref> After DARPA initiated the pioneering [[ARPANET]] in 1969, [[Steve Crocker]] established a "Networking Working Group" which developed a host-host protocol, the [[Network Control Program (ARPANET)|Network Control Program]] (NCP).{{Ref RFC|1000}} In the early 1970s, DARPA started work on several other data transmission technologies, including mobile packet radio, packet satellite service, local area networks, and other data networks in the public and private domains. In 1972, [[Bob Kahn]] joined the DARPA [[Information Processing Technology Office]], where he worked on both satellite packet networks and ground-based radio packet networks, and recognized the value of being able to communicate across both. In the spring of 1973, [[Vinton Cerf]] joined Kahn with the goal of designing the next protocol generation for the ARPANET to enable [[internetworking]].<ref>{{Cite book |last1=Hafner |first1=Katie |url=http://archive.org/details/wherewizardsstay00haf_vgj |title=Where wizards stay up late : the origins of the Internet |last2=Lyon |first2=Matthew |date=1996 |publisher=New York : Simon & Schuster |others=Internet Archive |isbn=978-0-684-81201-4 |page=263}}</ref><ref name=":0">{{cite book |last1=Russell |first1=Andrew L. |url=https://books.google.com/books?id=jqroAgAAQBAJ&pg=PA196 |title=Open standards and the digital age: history, ideology, and networks |date=2014 |publisher=Cambridge Univ Press |isbn=978-1107039193 |location=New York |page=196 |access-date=December 20, 2022 |archive-date=December 28, 2022 |archive-url=https://web.archive.org/web/20221228072845/https://books.google.com/books?id=jqroAgAAQBAJ&pg=PA196 |url-status=live }}</ref> They drew on the experience from the ARPANET research community, the [[International Network Working Group]], which Cerf chaired, and researchers at [[Xerox PARC]].<ref name="ZVVpe">{{Cite book|last=Abbate|first=Janet|author-link=Janet Abbate|url=https://books.google.com/books?id=E2BdY6WQo4AC&pg=PA123|title=Inventing the Internet|date=2000|publisher=MIT Press|isbn=978-0-262-51115-5|pages=123–4|language=en|access-date=May 15, 2020|archive-date=January 17, 2023|archive-url=https://web.archive.org/web/20230117175132/https://books.google.com/books?id=E2BdY6WQo4AC&pg=PA123|url-status=live}}</ref><ref>{{Citation |last=Taylor |first=Bob |title=Oral History of Robert (Bob) W. Taylor |date=October 11, 2008 |url=http://archive.computerhistory.org/resources/access/text/2013/05/102702015-05-01-acc.pdf |journal=Computer History Museum Archive |volume=CHM Reference number: X5059.2009 |page=28}}</ref><ref>{{Cite book |last=Isaacson |first=Walter |url=http://archive.org/details/innovatorshowgro0000isaa_p2p3 |title=The innovators : how a group of hackers, geniuses, and geeks created the digital revolution |date=2014 |publisher=New York : Simon & Schuster |others=Internet Archive |isbn=978-1-4767-0869-0}}</ref>

By the summer of 1973, Kahn and Cerf had worked out a fundamental reformulation, in which the differences between local network protocols were hidden by using a common [[internetwork protocol]], and, instead of the network being responsible for reliability, as in the existing ARPANET protocols, this function was delegated to the hosts. Cerf credits [[Louis Pouzin]] and [[Hubert Zimmermann]], designers of the [[CYCLADES]] network, with important influences on this design.<ref name="YSZAX">{{Cite journal|last1=Cerf|first1=V.|last2=Kahn|first2=R.|date=1974|title=A Protocol for Packet Network Intercommunication|url=https://www.cs.princeton.edu/courses/archive/fall06/cos561/papers/cerf74.pdf|journal=IEEE Transactions on Communications|volume=22|issue=5|pages=637–648|doi=10.1109/TCOM.1974.1092259|issn=1558-0857|quote=The authors wish to thank a number of colleagues for helpful comments during early discussions of international network protocols, especially R. Metcalfe, R. Scantlebury, D. Walden, and H. Zimmerman; D. Davies and L. Pouzin who constructively commented on the fragmentation and accounting issues; and S. Crocker who commented on the creation and destruction of associations.|access-date=October 18, 2015|archive-date=October 10, 2022|archive-url=https://ghostarchive.org/archive/20221010/https://www.cs.princeton.edu/courses/archive/fall06/cos561/papers/cerf74.pdf|url-status=live}}</ref><ref name="MevuR">{{cite news|date=13 December 2013|title=The internet's fifth man|work=Economist|url=https://www.economist.com/news/technology-quarterly/21590765-louis-pouzin-helped-create-internet-now-he-campaigning-ensure-its|access-date=11 September 2017|quote=In the early 1970s Mr Pouzin created an innovative data network that linked locations in France, Italy and Britain. Its simplicity and efficiency pointed the way to a network that could connect not just dozens of machines, but millions of them. It captured the imagination of Dr Cerf and Dr Kahn, who included aspects of its design in the protocols that now power the internet.|archive-date=April 19, 2020|archive-url=https://web.archive.org/web/20200419230318/https://www.economist.com/news/technology-quarterly/21590765-louis-pouzin-helped-create-internet-now-he-campaigning-ensure-its|url-status=live}}</ref> The new protocol was implemented as the [[Transmission Control Program]] in 1974 by Cerf, [[Yogen Dalal]] and Carl Sunshine.{{Ref RFC|675}}

Initially, the Transmission Control Program (the [[Internet Protocol]] did not then exist as a separate protocol) provided only a [[reliable byte stream]] service to its users, not [[datagram]]s.<ref name="TCP2">{{Cite web|url=https://www.rfc-editor.org/ien/ien5.pdf|title=Specification of Internet Transmission Control Protocol TCP (Version 2)|first=Vinton|last=Cerf|author-link=Vint Cerf|date=March 1977|access-date=2022-08-04|archive-date=May 25, 2022|archive-url=https://web.archive.org/web/20220525061950/https://www.rfc-editor.org/ien/ien5.pdf|url-status=live}}</ref> Several versions were developed through the [[Internet Experiment Note]] series.<ref name=":30" /> As experience with the protocol grew, collaborators recommended division of functionality into layers of distinct protocols, allowing users direct access to datagram service. Advocates included [[Bob Metcalfe]] and Yogen Dalal at Xerox PARC;<ref name="BpyJd">{{cite book |last1=Panzaris |first1=Georgios |url=https://books.google.com/books?id=9yMhAQAAIAAJ |title=Machines and romances: the technical and narrative construction of networked computing as a general-purpose platform, 1960–1995 |date=2008 |publisher=[[Stanford University]] |page=128 |access-date=September 5, 2019 |archive-url=https://web.archive.org/web/20230117175134/https://books.google.com/books?id=9yMhAQAAIAAJ |archive-date=January 17, 2023 |url-status=live}}</ref><ref name="2J9cz">{{cite book |last1=Pelkey |first1=James L. |url=https://historyofcomputercommunications.info/ |title=Entrepreneurial Capitalism and Innovation: A History of Computer Communications, 1968–1988 |date=2007 |chapter=Yogen Dalal |access-date=8 October 2020 |chapter-url=https://historyofcomputercommunications.info/interviews/yogen-dalal/ |archive-url=https://web.archive.org/web/20221008232443/https://historyofcomputercommunications.info/ |archive-date=October 8, 2022 |url-status=live}}</ref> [[Danny Cohen (computer scientist)|Danny Cohen]], who needed it for his [[packet voice]] work; and [[Jonathan Postel]] of the University of Southern California's [[Information Sciences Institute]], who edited the [[Request for Comments]] (RFCs), the technical and strategic document series that has both documented and catalyzed Internet development.<ref name="i1TtW">Internet Hall of Fame</ref> Postel stated, "We are screwing up in our design of Internet protocols by violating the principle of layering."<ref name="xgruR">{{citation|url=https://www.rfc-editor.org/ien/ien2.txt|first=Jon|last=Postel|author-link=Jon Postel|title=2.3.3.2 Comments on Internet Protocol and TCP|id=IEN 2|date=15 August 1977|access-date=June 11, 2016|archive-date=May 16, 2019|archive-url=https://web.archive.org/web/20190516055704/http://www.rfc-editor.org/ien/ien2.txt|url-status=live}}</ref> Encapsulation of different mechanisms was intended to create an environment where the upper layers could access only what was needed from the lower layers. A monolithic design would be inflexible and lead to scalability issues. In [[IPv4|version 4]], written in 1978, Postel split the Transmission Control Program into two distinct protocols, the [[Internet Protocol]] as connectionless layer and the [[Transmission Control Protocol]] as a reliable [[connection-oriented service]].<ref>Abbate, ''Inventing the Internet'', 129–30.</ref><ref>{{cite journal |author=Vinton G. Cerf |date=October 1980 |title=Protocols for Interconnected Packet Networks |journal=ACM SIGCOMM Computer Communication Review |volume=10 |issue=4 |pages=10–11 |authorlink=Vint Cerf}}</ref><ref>{{Cite thesis |last=Russell |first=Andrew L. |title="Industrial Legislatures": Consensus Standardization in the Second and Third Industrial Revolutions |date=2007 |degree=PhD |publisher=Johns Hopkins University |url=https://jscholarship.library.jhu.edu/bitstream/handle/1774.2/32576/alr-diss-08012007-CBO-opt.pdf |access-date=December 28, 2022 |archive-date=December 28, 2022 |archive-url=https://web.archive.org/web/20221228000055/https://jscholarship.library.jhu.edu/bitstream/handle/1774.2/32576/alr-diss-08012007-CBO-opt.pdf |url-status=live }}</ref><ref group ="nb">For records of discussions leading up to the TCP/IP split, see the series of [[Internet Experiment Notes]] at [https://www.rfc-editor.org/ien/ien-index.html the Internet Experiment Notes Index].</ref>

The design of the network included the recognition that it should provide only the functions of efficiently transmitting and routing traffic between end nodes and that all other intelligence should be located at the edge of the network, in the end nodes. This [[end-to-end principle]] was pioneered by Louis Pouzin in the CYCLADES network,<ref name="Bennett2009">{{cite web |last1=Bennett |first1=Richard |date=September 2009 |title=Designed for Change: End-to-End Arguments, Internet Innovation, and the Net Neutrality Debate |url=https://www.itif.org/files/2009-designed-for-change.pdf |access-date=11 September 2017 |publisher=Information Technology and Innovation Foundation |pages=7, 11}}</ref> based on the ideas of [[Donald Davies]].<ref name="Pelkey2">{{cite book |last=Pelkey |first=James |url=https://www.historyofcomputercommunications.info/section/8.3/cyclades-network-and-louis-pouzin-1971-1972/ |title=Entrepreneurial Capitalism and Innovation: A History of Computer Communications 1968-1988 |chapter=8.3 CYCLADES Network and Louis Pouzin 1971-1972 |quote=The inspiration for datagrams had two sources. One was Donald Davies’ studies. He had done some simulation of datagram networks, although he had not built any, and it looked technically viable. The second inspiration was I like things simple. I didn’t see any real technical motivation to overlay two levels of end-to-end protocols. I thought one was enough. |access-date=2021-11-21 |archive-url=https://web.archive.org/web/20210617093154/https://www.historyofcomputercommunications.info/section/8.3/cyclades-network-and-louis-pouzin-1971-1972/ |archive-date=2021-06-17 |url-status=dead}}</ref><ref name=":5">{{cite conference |last1=Davies |first1=Donald |last2=Bartlett |first2=Keith |last3=Scantlebury |first3=Roger |last4=Wilkinson |first4=Peter |date=October 1967 |title=A Digital Communication Network for Computers Giving Rapid Response at remote Terminals |url=https://people.mpi-sws.org/~gummadi/teaching/sp07/sys_seminar/how_did_erope_blow_this_vision.pdf |conference=ACM Symposium on Operating Systems Principles |archive-url=https://ghostarchive.org/archive/20221010/https://people.mpi-sws.org/~gummadi/teaching/sp07/sys_seminar/how_did_erope_blow_this_vision.pdf |archive-date=2022-10-10 |access-date=2020-09-15 |url-status=live |quote=all users of the network will provide themselves with some kind of error control}}</ref> Using this design, it became possible to connect other networks to the ARPANET that used the same principle, irrespective of other local characteristics, thereby solving Kahn's initial internetworking problem. A popular expression is that TCP/IP, the eventual product of Cerf and Kahn's work, can run over "two tin cans and a string."{{citation needed|reason=I can only find possibly circular references for this phrase.|date=November 2017}} Years later, as a [[April Fools' Day|joke]] in 1999, the [[IP over Avian Carriers]] formal protocol specification was created{{Ref RFC|1149}} and successfully tested two years later. 10 years later still, it was adapted for IPv6.{{Ref RFC|6214}}

DARPA contracted with [[BBN Technologies]], [[Stanford University]], and the [[University College London]] to develop operational versions of the protocol on several hardware platforms.<ref name="IjTdeF">{{cite web |author1=by Vinton Cerf, as told to Bernard Aboba |date=1993 |title=How the Internet Came to Be |url=http://elk.informatik.hs-augsburg.de/tmp/cdrom-oss/CerfHowInternetCame2B.html |url-status=dead |archive-url=https://web.archive.org/web/20170926042220/http://elk.informatik.hs-augsburg.de/tmp/cdrom-oss/CerfHowInternetCame2B.html |archive-date=26 September 2017 |access-date=25 September 2017 |quote=We began doing concurrent implementations at Stanford, BBN, and University College London. So effort at developing the Internet protocols was international from the beginning.}}</ref> During development of the protocol the version number of the packet routing layer progressed from version 1 to version 4, the latter of which was installed in the ARPANET in 1983. It became known as ''[[Internet Protocol version 4]]'' (IPv4) as the protocol that is still in use in the Internet, alongside its current successor, [[Internet Protocol version 6]] (IPv6).