Editing History of the Internet (section)

===TCP/IP===
{{Main|Internet protocol suite}}
{{See also|Transmission Control Protocol|Internet Protocol}}
[[File:First Internet Demonstration, 1977.jpg|thumb|First Internet demonstration, linking the [[ARPANET]], [[PRNET]], and [[SATNET]] on November 22, 1977]]
With so many different networking methods seeking interconnection, a method was needed to unify them. [[Louis Pouzin]] initiated the [[CYCLADES]] project in 1972,<ref name=":21">{{Cite conference |last=Pouzin |first=Louis |date=1973 |title=Presentation and major design aspects of the CYCLADES computer network |url=http://portal.acm.org/citation.cfm?doid=800280.811034 |language=en |publisher=ACM Press |pages=80–87 |doi=10.1145/800280.811034 |doi-access=free |book-title=DATACOMM '73: Proceedings of the third ACM symposium on Data communications and Data networks}}</ref> building on the work of [[Donald Davies]] and the ARPANET.<ref name="Pelkey8.3">{{cite book |last=Pelkey |first=James |title=Entrepreneurial Capitalism and Innovation: A History of Computer Communications 1968–1988 |chapter=8.3 CYCLADES Network and Louis Pouzin 1971–1972 |chapter-url=https://historyofcomputercommunications.info/section/8.3/CYCLADES-Network-and-Louis-Pouzin-1971-1972/}}</ref> An [[International Network Working Group]] formed in 1972; active members included [[Vint Cerf]] from [[Stanford University]], Alex McKenzie from [[Bolt Beranek & Newman|BBN]], Donald Davies and [[Roger Scantlebury]] from [[National Physical Laboratory (United Kingdom)|NPL]], and Louis Pouzin and [[Hubert Zimmermann]] from [[French Institute for Research in Computer Science and Automation|IRIA]].<ref>{{Cite journal|last=McKenzie|first=Alexander|date=2011|title=INWG and the Conception of the Internet: An Eyewitness Account|journal=IEEE Annals of the History of Computing|volume=33|issue=1|pages=66–71|doi=10.1109/MAHC.2011.9|s2cid=206443072 }}</ref><ref name="ieee201703">{{cite journal |last1=Russell |first1=A. L. |title=The internet that wasn't |journal=IEEE Spectrum |date=August 2013 |volume=50 |issue=8 |pages=39–43 |doi=10.1109/MSPEC.2013.6565559 |s2cid=11259224 |url=https://spectrum.ieee.org/osi-the-internet-that-wasnt |url-access=subscription }}</ref><ref>{{Cite web|title=Vinton Cerf: How the Internet Came to Be|url=http://www.netvalley.com/archives/mirrors/cerf-how-inet.html|access-date=2021-12-21|website=www.netvalley.com}}</ref> Pouzin coined the term ''[[catenet]]'' for concatenated network. [[Robert Metcalfe|Bob Metcalfe]] at [[PARC (company)|Xerox PARC]] outlined the idea of [[Ethernet]] and [[PARC Universal Packet]] (PUP) for [[internetworking]]. [[Robert E. Kahn|Bob Kahn]], now at [[DARPA]], recruited Vint Cerf to work with him on the problem. By 1973, these groups had worked out a fundamental reformulation, in which the differences between network protocols were hidden by using a common [[internetworking]] protocol. Instead of the network being responsible for reliability, as in the ARPANET, the hosts became responsible.<ref name=":3" /><ref name=":5">{{cite journal |last=Hauben |first=Ronda |year=2004 |title=The Internet: On its International Origins and Collaborative Vision |url=http://www.ais.org/~jrh/acn/ACn12-2.a03.txt |journal=Amateur Computerist |volume=12 |issue=2 |access-date=May 29, 2009}}</ref>

Cerf and Kahn published their ideas in May 1974,<ref name=":7">{{cite journal |last1=Cerf |first1=V. |last2=Kahn |first2=R. |title=A Protocol for Packet Network Intercommunication |journal=IEEE Transactions on Communications |date=May 1974 |volume=22 |issue=5 |pages=637–648 |doi=10.1109/TCOM.1974.1092259 |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.}}</ref> which incorporated concepts implemented by Louis Pouzin and Hubert Zimmermann in the CYCLADES network.<ref>{{Cite book |last=Green |first=Lelia |url=https://www.worldcat.org/title/504280762 |title=The internet: an introduction to new media |date=2010 |publisher=Berg |isbn=978-1-84788-299-8 |series=Berg new media series |page=31 |oclc=504280762 |quote=The original ARPANET design had made data integrity part of the IMP's store-and-forward role, but Cyclades end-to-end protocol greatly simplified the packet switching operations of the network. ... The idea was to adopt several principles from Cyclades and invert the ARPANET model to minimise international differences.}}</ref><ref>{{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.}}</ref> The specification of the resulting protocol, the [[Transmission Control Program]], was published as {{IETF RFC|675}} by the Network Working Group in December 1974.<ref>{{cite ietf |author1=[[Vint Cerf]] |author2=[[Yogen Dalal]] |author3=Carl Sunshine |date=December 1974 |RFC=675 |title=Specification of Internet Transmission Control Protocol}}</ref> It contains the first attested use of the term ''internet'', as a shorthand for internetwork. This software was monolithic in design using two [[simplex communication]] channels for each user session.

With the role of the network reduced to a core of functionality, it became possible to exchange traffic with other networks independently from their detailed characteristics, thereby solving the fundamental problems of internetworking. DARPA agreed to fund the development of prototype software. Testing began in 1975 through concurrent implementations at Stanford, BBN and [[University College London]] (UCL).<ref name=":4" /> After several years of work, the first demonstration of a gateway between the [[PRNET|Packet Radio network]] (PRNET) in the SF Bay area and the ARPANET was conducted by the [[SRI International|Stanford Research Institute]]. On November 22, 1977, a three network demonstration was conducted including the ARPANET, the SRI's [[Packet Radio Van]] on the Packet Radio Network and the [[Atlantic Packet Satellite Network]] (SATNET) including a node at UCL.<ref>{{cite web |url=http://www.computerhistory.org/about/press_relations/releases/20071101/ |access-date=November 22, 2007 |title=Computer History Museum and Web History Center Celebrate 30th Anniversary of Internet Milestone  }}</ref><ref>{{cite news|url=http://news.cnet.com/Internet-van-helped-drive-evolution-of-the-Web/2100-1033_3-6217511.html|title='Internet van' helped drive evolution of the Web|first=Erica|last=Ogg|work=[[CNET]]|date=2007-11-08|access-date=2011-11-12}}</ref>

The software was redesigned as a modular protocol stack, using full-duplex channels; between 1976 and 1977, [[Yogen Dalal]] and Robert Metcalfe among others, proposed separating TCP's [[routing]] and transmission control functions into two discrete layers,<ref name="Panzaris">{{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|quote=Despite the misgivings of Xerox Corporation (which intended to make PUP the basis of a proprietary commercial networking product), researchers at Xerox PARC, including ARPANET pioneers Robert Metcalfe and Yogen Dalal, shared the basic contours of their research with colleagues at TCP and Internet working group meetings in 1976 and 1977, suggesting the possible benefits of separating TCPs routing and transmission control functions into two discrete layers.}}</ref><ref name="Pelkey-Dalal">{{cite book|last1=Pelkey|first1=James L.|title=Entrepreneurial Capitalism and Innovation: A History of Computer Communications, 1968–1988|date=2007|chapter=Yogen Dalal|access-date=5 September 2019|chapter-url=http://www.historyofcomputercommunications.info/Individuals/abstracts/yogen-dalal.html|archive-date=September 5, 2019|archive-url=https://web.archive.org/web/20190905162105/http://www.historyofcomputercommunications.info/Individuals/abstracts/yogen-dalal.html}}</ref> which led to the splitting of the Transmission Control Program into the [[Transmission Control Protocol]] (TCP) and the [[Internet Protocol]] (IP) in version 3 in 1978.<ref name="Pelkey-Dalal" /><ref name=":0">{{cite web|title=BGP Analysis Reports|url=http://bgp.potaroo.net/index-bgp.html|access-date=2013-01-09}}</ref> [[IPv4|Version 4]] was described in [[IETF]] publication RFC 791 (September 1981), 792 and 793. It was installed on [[SATNET]] in 1982 and the ARPANET in January 1983 after the DoD made it standard for all military computer networking.<ref>{{Cite web|title=TCP/IP Internet Protocol|url=https://www.livinginternet.com/i/ii_tcpip.htm|access-date=2020-02-20|website=www.livinginternet.com|archive-date=July 26, 2020|archive-url=https://web.archive.org/web/20200726154118/https://www.livinginternet.com/i/ii_tcpip.htm}}</ref><ref>{{cite ietf |author=[[Jon Postel]] |title=NCP/TCP Transition Plan |RFC= 801}}</ref> This resulted in a networking model that became known informally as TCP/IP. It was also referred to as the Department of Defense (DoD) model or DARPA model.<ref>{{Cite web|title=The TCP/IP Guide – TCP/IP Architecture and the TCP/IP Model|url=http://www.tcpipguide.com/free/t_TCPIPArchitectureandtheTCPIPModel.htm|access-date=2020-02-11|website=www.tcpipguide.com}}</ref> Cerf credits his graduate students Yogen Dalal, Carl Sunshine, [[Judy Estrin]], Richard A. Karp, and [[Gérard Le Lann]] with important work on the design and testing.<ref>{{cite web|date=24 April 1990|title=Smithsonian Oral and Video Histories: Vinton Cerf|url=https://americanhistory.si.edu/comphist/vc1.html|access-date=23 September 2019|website=[[National Museum of American History]]|publisher=[[Smithsonian Institution]]}}</ref> DARPA sponsored or encouraged the [[Internet protocol suite#Adoption|development of TCP/IP implementations]] for many operating systems.

[[Image:IPv4 address structure and writing systems-en.svg|300px|thumb|Decomposition of the quad-dotted IPv4 address representation to its [[Binary numeral system|binary]] value]]