Editing Internetworking (section)

==History==
The first international heterogenous [[resource sharing]] network was developed by the computer science department at [[University College London]] (UCL) who interconnected the [[ARPANET]] with early [[Internet in the United Kingdom#History|British academic networks]] beginning in 1973.<ref name="M. Ziewitz & I. Brown">{{cite book |author=M. Ziewitz & I. Brown |url=https://books.google.com/books?id=QgI1_r61JFQC&pg=PA7 |title=Research Handbook on Governance of the Internet |date=2013 |publisher=[[Edward Elgar Publishing]] |isbn=978-1849805049 |page=7 |access-date=2015-08-16}}</ref><ref>{{Cite journal |last=Kirstein |first=P.T. |date=1999 |title=Early experiences with the Arpanet and Internet in the United Kingdom |url=https://pdfs.semanticscholar.org/4773/f19792f9fce8eacba72e5f8c2a021414e52d.pdf |url-status=dead |journal=IEEE Annals of the History of Computing |volume=21 |issue=1 |pages=38–44 |doi=10.1109/85.759368 |issn=1934-1547 |archive-url=https://web.archive.org/web/20200207092443/https://pdfs.semanticscholar.org/4773/f19792f9fce8eacba72e5f8c2a021414e52d.pdf |archive-date=2020-02-07 |quote=From the outset of the project, we aimed not only to carry out innovative research, but also to provide network services to UK and U.S. groups that wished to cooperate. |s2cid=1558618}}</ref><ref>{{cite news |date=19 November 2003 |title=30 years of the international internet |work=[[BBC News]] |url=http://news.bbc.co.uk/1/hi/technology/3280897.stm |access-date=22 June 2012}}</ref> In the ARPANET, the network elements used to connect individual networks were called [[gateway (telecommunications)|gateways]], but the term has been deprecated in this context, because of possible confusion with functionally different devices. By 1973-4, researchers in France, the United States, and the United Kingdom had worked out an approach to internetworking where the differences between network protocols were hidden by using a common internetwork protocol, and instead of the network being responsible for reliability, as in the ARPANET, the hosts became responsible, as demonstrated in the [[CYCLADES]] network.<ref name=":3">{{cite web|date=27 October 2009|title=The Computer History Museum, SRI International, and BBN Celebrate the 40th Anniversary of First ARPANET Transmission, Precursor to Today's Internet|url=https://www.sri.com/newsroom/press-releases/computer-history-museum-sri-international-and-bbn-celebrate-40th-anniversary|url-status=dead|archive-url=https://web.archive.org/web/20190329134941/https://www.sri.com/newsroom/press-releases/computer-history-museum-sri-international-and-bbn-celebrate-40th-anniversary|archive-date=March 29, 2019|access-date=25 September 2017|publisher=SRI International|quote=But the ARPANET itself had now become an island, with no links to the other networks that had sprung up. By the early 1970s, researchers in France, the UK, and the U.S. began developing ways of connecting networks to each other, a process known as internetworking.}}</ref><ref>{{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.}}</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> Researchers at [[Xerox PARC]] outlined the idea of [[Ethernet]] and the [[PARC Universal Packet]] (PUP) for internetworking.<ref>{{Cite web |title=8.7 Ethernet and Robert Metcalfe and Xerox PARC 1971-1975 |url=https://historyofcomputercommunications.info/section/8.7/ethernet-and-robert-metcalfe-and-xerox-parc-1971-1975/}}</ref><ref name="Moschovitisp78-9">{{harvnb|Moschovitis|1999|p=[https://archive.org/details/historyofinterne0000unse/page/78/mode/2up 78-9]}}</ref> Research at the [[National Physical Laboratory (United Kingdom)|National Physical Laboratory]] in the United Kingdom confirmed establishing a common host protocol would be more reliable and efficient.<ref>{{Cite book|last=Abbate|first=Janet|author-link=Janet Abbate|url=https://books.google.com/books?id=E2BdY6WQo4AC&pg=PA125|title=Inventing the Internet|date=2000|publisher=MIT Press|isbn=978-0-262-51115-5|pages=125|language=en}}</ref> The ARPANET connection to UCL later evolved into [[SATNET]]. In 1977, ARPA demonstrated a three-way internetworking experiment, which linked a mobile vehicle in [[PRNET]] with nodes in the ARPANET, and, via SATNET, to nodes at UCL. The [[X.25]] protocol, on which [[public data network]]s were based in the 1970s and 1980s, was supplemented by the [[X.75]] protocol which enabled internetworking.

Today the interconnecting gateways are called [[Router (computing)|router]]s. The definition of an internetwork today includes the connection of other types of computer networks such as [[personal area network]]s.

=== Catenet ===
Catenet, a short-form of ''(con)catenating networks,'' is obsolete terminolgy for a system of [[packet-switched]] communication networks interconnected via [[Gateway (telecommunications)|gateways]].<ref name="ien48" />

The term was coined by [[Louis Pouzin]], who designed the [[CYCLADES]] network, in an October 1973 note circulated to the [[International Network Working Group]],<ref>{{Cite journal |last1=Russell |first1=Andrew L. |last2=Schafer |first2=Valérie |date=2014 |title=In the Shadow of ARPANET and Internet: Louis Pouzin and the Cyclades Network in the 1970s |url=https://www.jstor.org/stable/24468474 |journal=Technology and Culture |volume=55 |issue=4 |pages=893–894 |issn=0040-165X |jstor=24468474}}</ref><ref name=":02">{{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 |issn=1934-1547 |s2cid=206443072}}</ref> which was published in a 1974 paper "''A Proposal for Interconnecting Packet Switching Networks"''.<ref>''A Proposal for Interconnecting Packet Switching Networks'', L. Pouzin, Proceedings of EUROCOMP, Brunel University, May 1974, pp. 1023-36.</ref> Pouzin was a pioneer of internetworking at a time when ''network'' meant what is now called a [[local area network]]. Catenet was the concept of linking these networks into a ''network of networks'' with specifications for compatibility of addressing and routing. The term was used in technical writing in the late 1970s and early 1980s,<ref>{{Cite web |title=catenet - Google Search |url=https://www.google.com/search?udm=36&q=catenet&safe=active&ssui=on |access-date=2025-04-28 |website=www.google.com}}</ref> including in [[Request for Comments|RFCs]] and [[Internet Experiment Note|IENs]].<ref>{{Cite web |title=Google Search |url=https://www.google.com/search?q=catenet+site:https://www.rfc-editor.org/&safe=active&ssui=on |access-date=2025-04-28 |website=www.google.com}}</ref> Catenet was gradually displaced by the short-form of the term internetwork, ''internet'' (lower-case ''i''), when the [[Internet Protocol]] spread more widely from the mid 1980s and the use of the term internet took on a broader sense and became well known in the 1990s.<ref>{{Cite web |title=Google Books Ngram Viewer |url=https://books.google.com/ngrams/graph?content=catenet,internet&year_start=1970&year_end=1995&corpus=en&smoothing=3&case_insensitive=false |access-date=2025-04-28 |website=books.google.com |language=en}}</ref><ref>{{Cite IETF |RFC=1011}}</ref><ref>{{Cite IETF |RFC=1087}}</ref><ref>{{Cite IETF |RFC=1392}}</ref><ref>{{Cite IETF |RFC=1462}}</ref><ref>{{Cite IETF |RFC=1935}}</ref><ref>{{Cite IETF |RFC=1958}}</ref><ref>{{Cite IETF |RFC=2002}}</ref>