International Network Working Group

The International Network Working Group (INWG) was a group of prominent computer science researchers in the 1970s who studied and developed standards and protocols for interconnection of computer networks. Set up in 1972 as an informal group to consider the technical issues involved in connecting different networks, its goal was to develop an international standard protocol for internetworking. INWG became a subcommittee of the International Federation for Information Processing (IFIP) the following year. Concepts developed by members of the group contributed to the Protocol for Packet Network Intercommunication proposed by Vint Cerf and Bob Kahn in 1974 and the Transmission Control Protocol and Internet Protocol (TCP/IP) that emerged later.

History

Founding and IFIP affiliation

The International Network Working Group was formed by Steve Crocker, Louis Pouzin, Donald Davies, and Peter Kirstein in June 1972 in Paris at a networking conference organised by Pouzin.^[1][2] Crocker saw that it would be useful to have an international version of the Network Working Group, which developed the Network Control Program for the ARPANET.^[3]

At the International Conference on Computer Communication (ICCC) in Washington D.C. in October 1972, Vint Cerf was approved as INWG's Chair on Crocker's recommendation.^{[4][5][6][nb 1]} The group included American researchers representing the ARPANET^{[nb 2]} and the Merit network, the French CYCLADES and RCP networks,^{[nb 3]} and British teams working on the NPL network, EPSS, and European Informatics Network.^[4][7]

During early 1973, Pouzin arranged affiliation with the International Federation for Information Processing (IFIP). INWG became IFIP Working Group 1 under Technical Committee 6 (Data Communication) with the title "International Packet Switching for Computer Sharing" (WG6.1). This standing, although informal, enabled the group to provide technical input on packet networking to CCITT and ISO.^{[4][6][8][9][10]} Its purpose was to study and develop "international standard protocols for internetworking".^[11]

INWG published a series numbered notes, some of which were also RfCs.^[4][12]

Gateways/routers

The idea for a router (called a gateway at the time) initially came about through INWG.^[13] These gateway devices were different from most previous packet switching schemes in two ways. First, they connected dissimilar kinds of networks, such as serial lines and local area networks. Second, they were connectionless devices, which had no role in assuring that traffic was delivered reliably, leaving that function entirely to the hosts.^[14] This particular idea, the end-to-end principle, had been pioneered in the CYCLADES network.^[15]

Proposal for an international end-to-end protocol

INWG met in New York in June 1973. Attendees included Cerf, Bob Kahn, Alex McKenzie, Bob Metcalfe, Roger Scantlebury, John Shoch and Hubert Zimmermann, among others.^{[4][16][17][18]} They discussed a first draft of an International Transmission Protocol (ITP).^[4] Zimmermann and Metcalfe dominated the discussions; Zimmermann had been working with Pouzin on the CYCLADES network while Metclafe, Shoch and others at Xerox PARC had been developing the idea of Ethernet and the PARC Universal Packet (PUP) for internetworking.^[19][16] Notes from the meetings were recorded by Cerf and McKenzie, which was circulated after the meeting (INWG 28).^[4][12] There was a follow-up meeting in July. Gerard LeLann and G. Grossman made contributions after the June meeting.^[4]

Building on this work, in September 1973, Kahn and Cerf presented a paper, Host and Process Level Protocols for Internetwork Communication, at the next INWG meeting at the University of Sussex in England (INWG 39).^[20] Their ideas were refined further in long discussions with Davies, Scantlebury, Pouzin and Zimmerman.^[21]

Pouzin circulated a paper on Interconnection of Packet Switching Networks in October 1973 (INWG 42),^[4][12] in which he introduced the term catenet for an interconnected network.^[4][22] Zimmerman and Michel Elie wrote a Proposed Standard Host-Host Protocol for Heterogenous Computer Networks: Transport Protocol in December 1973 (INWG 43).^[12] Pouzin updated his paper with A Proposal for Interconnecting Packet Switching Networks in March 1974 (INWG 60),^[12] published two months later in May.^[23] Zimmerman and Elie circulated a Standard host-host protocol for heterogeneous computer networks in April 1974 (INWG 61).^[12] Pouzin published An integrated approach to network protocols in May 1975.^[24]

Kahn and Cerf published a significantly updated and refined version of their proposal in May 1974, A Protocol for Packet Network Intercommunication. A later version of the paper acknowledged several people including members of INWG and attendees at the June 1973 meeting.^[25] It was updated in INWG 72/RFC 675 in December 1974 by Cerf, Yogen Dalal and Carl Sunshine, which introduced the term internet as a shorthand for internetwork.^[26]

The Internet architecture as seen by the INWG.^[27]

Two competing proposals had evolved,^[28] the early Transmission Control Program (TCP), originally proposed by Kahn and Cerf, and the CYCLADES transport station (TS) protocol, proposed by Pouzin, Zimmermann and Elie. There were two sticking points: whether there should be fragmentation of datagrams (as in TCP) or standard-sized datagrams (as in TS); and whether the data flow was an undifferentiated stream or maintained the integrity of the units sent. These were not major differences. After "hot debate", McKenzie proposed a synthesis in December 1974, Internetwork Host-to-Host Protocol (INWG 74), which he refined the following year with Cerf, Scantlebury and Zimmerman (INWG 96).^{[4][19][27][29]}

After reaching agreement with the wider group,^{[nb 4]} a Proposal for an international end to end protocol, was published by Cerf, McKenzie, Scantlebury, and Zimmermann in 1976.^[30][31][32] It was presented to the CCITT and ISO by Derek Barber, who became INWG chair earlier that year.^[4] Although the protocol was adopted by networks in Europe,^[33] it was not adopted by the CCITT, ISO nor the ARPANET.^[4]

The CCITT went on to adopt the X.25 standard in 1976, based on virtual circuits. ARPA began testing TCP in 1975 at Stanford, BBN and University College London.^[34] Ultimately, ARPA developed the Internet protocol suite, including the Internet Protocol as connectionless layer and the Transmission Control Protocol as a reliable connection-oriented service, which reflects concepts in Pouzin's CYCLADES project.^[35]

Email

Ray Tomlinson is well known as the creator of network mail (i.e., email) in INWG Protocol note 2 (a separate series of INWG notes), in September 1974.^[4] Derek Barber proposed an electronic mail protocol in 1979 in INWG 192 and implemented it on the European Informatics Network.^[36] This was referenced by Jon Postel in his early work on Internet email, published in the Internet Experiment Note series.^[37]

Later

Alex McKenzie served as chair from 1979-1982 and Secretary beginning in 1983.^[11] Carl Sunshine, who had worked with Vint Cerf and Yogen Dalal at Stanford on the first TCP specification, subsequently served as INWG chair until 1987, when Harry Rudin took over.^[38]

Later international work led to the OSI model in 1984, of which many members of the INWG became advocates.^[5][39] During the Protocol Wars of the late 1980s and early 1990s, engineers, organizations and nations became polarized over the issue of which standard, the OSI model or the Internet protocol suite would result in the best and most robust computer networks. ARPA partnerships with the telecommunication and computer industry led to widespread private sector adoption of the Internet protocol suite as a communication protocol.^[5][40][41]

The INWG continued to work on protocol design and formal specification until the 1990s when it disbanded as the Internet grew rapidly.^[4] Nonetheless, issues with the Internet Protocol suite remain and alternatives have been proposed building on INWG ideas such as Recursive Internetwork Architecture.^[27]

Legacy

The work of INWG was a significant step in the creation of the Transmission Control Program and ultimately the Internet.^[42]

... the International Network Working Group was created ... to draw a larger cohort of people into this whole question of how to design and build packet switch networks. That eventually led to the design of the Internet.

— Vint Cerf (2020)^[43]

Members

The group had about 100 members, including the following:^[4][9]

• Derek Barber
• B. Barker
• Vint Cerf
• W. Clipsham
• Donald Davies
• Rémi Despres
• V. Detwiler
• Frank Heart
• Alex McKenzie
• Louis Pouzin
• O. Riml
• Harry Rudin
• K. Samuelson
• K. Sandum
• Roger Scantlebury
• B. Sexton
• P. Shanks
• C.D. Shepard
• Carl Sunshine
• J. Tucker
• Barry Wessler
• Hubert Zimmerman

See also

• Coloured Book protocols
• History of email
• History of the Internet
• List of Internet pioneers
• Protocol Wars
• Public data network

Notes

1. Crocker recalls he allocated Cerf $50k funding for the role, although Kahn does not recall this.
2. More specifically, McKenzie represented BBN and Cerf represented Stanford University.
3. Remi Despres, who represented the French RCP, was also a member.
4. The group did not include Bob Kahn.

References

1. Pelkey, James. "8.3 CYCLADES Network and Louis Pouzin 1971–1972". Entrepreneurial Capitalism and Innovation: A History of Computer Communications 1968–1988.
2. Hafner & Lyon 1999, p. 222
3. "Internet founders say flexible framework was key to explosive growth". Princeton University. Retrieved 2020-02-07.
4. McKenzie, Alexander (2011). "INWG and the Conception of the Internet: An Eyewitness Account". IEEE Annals of the History of Computing. 33 (1): 66–71. doi:10.1109/MAHC.2011.9. ISSN 1934-1547. S2CID 206443072.
5. Andrew L. Russell (30 July 2013). "OSI: The Internet That Wasn't". IEEE Spectrum. Vol. 50, no. 8.
6. Abbate, Janet (2000). Inventing the Internet. MIT Press. pp. 123–4. ISBN 978-0-262-51115-5.
7. "The Computer History Museum, SRI International, and BBN Celebrate the 40th Anniversary of First ARPANET Transmission, Precursor to Today's Internet". SRI International. 27 October 2009. Archived from the original on March 29, 2019. Retrieved 25 September 2017. 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.
8. The "Hidden" Prehistory of European Research Networking. Trafford Publishing. ISBN 978-1-4669-3935-6.
9. Davies, Donald Watts (1979). Computer networks and their protocols. Internet Archive. Chichester, [Eng.]; New York : Wiley. p. 466. ISBN 9780471997504.
10. "Vinton Cerf : How the Internet Came to Be". www.netvalley.com. Retrieved 2021-12-22.
11. "Collection: Alex McKenzie collection of computer networking development records | University of Minnesota Archival Collections Guides". archives.lib.umn.edu. Retrieved 2023-01-27.
12. "General Notes index: 1-77, 98-111, 116-125 citing note number, author, and title; INWG Protocol Notes index: 1-10, 28-38 citing note number, author, title and date". umedia.lib.umn.edu. Retrieved 2024-05-29.
13. Davies, Shanks, Heart, Barker, Despres, Detwiler and Riml, "Report of Subgroup 1 on Communication System", INWG Note No. 1.
14. Edmondson-Yurkanan, Chris (2007). "SIGCOMM's archaeological journey into networking's past". Communications of the ACM. 50 (5): 63–68. doi:10.1145/1230819.1230840. ISSN 0001-0782. INWG#1: Report of Subgroup 1 on Communication System Requirements by Davies, Shanks, Heart, Barker, Despres, Detwiler, and Riml. They wrote: "It was agreed that interworkingbetween packet switching networks should not add complications to the hosts, considering that networks will probably be different and thus gatewaysbetween networks will be required. These gateways should be as uncomplicated as possible, whilst allowing as much freedom as possible for the design of individual networks". INWG#1 clarified that gateways and simplicity were accepted concepts when INWG was formed.
15. Bennett, Richard (September 2009). "Designed for Change: End-to-End Arguments, Internet Innovation, and the Net Neutrality Debate" (PDF). Information Technology and Innovation Foundation. pp. 7, 11. Retrieved 11 September 2017.
16. Taylor, Bob (October 11, 2008), "Oral History of Robert (Bob) W. Taylor" (PDF), Computer History Museum Archive, CHM Reference number: X5059.2009: 27–8
17. Isaacson, Walter (2014). The innovators : how a group of hackers, geniuses, and geeks created the digital revolution. Internet Archive. New York : Simon & Schuster. ISBN 978-1-4767-0869-0.
18. "Smithsonian Oral and Video Histories: Vinton Cerf". National Museum of American History. Smithsonian Institution. 24 April 1990. Retrieved 23 September 2019. Roger Scantlebury was one of the major players. And Donald Davies who ran, at least he was superintendent of the information systems division or something like that. I absolutely had a lot of interaction with NPL at the time. They in fact came to the ICCC 72 and they had been coming to previous meetings of what is now called Datacomm. Its first incarnation was a long title having to do with the analysis and optimization of computer communication networks, or something like that. This started in late 1969, I think, was when the first meeting happened in Pine Hill, Georgia. I didn't go to that one, but I went to the next one that was at Stanford, I think. That's where I met Scantlebury, I believe, for the first time. Then I had a lot more interaction with him. I would come to the UK fairly regularly, partly for IFIP or INWG reasons
19. Russell, Andrew L.; Schafer, Valérie (2014). "In the Shadow of ARPANET and Internet: Louis Pouzin and the Cyclades Network in the 1970s". Technology and Culture. 55 (4): 893–894. doi:10.1353/tech.2014.0096. ISSN 0040-165X. JSTOR 24468474.
20. Pelkey, James. "8.4 Transmission Control Protocol (TCP) 1973-1976". Entrepreneurial Capitalism and Innovation: A History of Computer Communications 1968–1988.
21. Hafner, Katie; Lyon, Matthew (1999-08-19) [1996]. Where Wizards Stay Up Late: The Origins Of The Internet. Simon and Schuster. pp. 225–6. ISBN 978-0-684-87216-2.
22. Vint Cerf (July 1978). "IEN 48: The Catenet Model for Internetworking". IETF. The term "catenet" was introduced by L. Pouzin.
23. A Proposal for Interconnecting Packet Switching Networks, L. Pouzin, Proceedings of EUROCOMP, Brunel University, May 1974, pp. 1023-36.
24. Pouzin, Louis (1975-05-19). "An integrated approach to network protocols". Proceedings of the May 19-22, 1975, national computer conference and exposition on - AFIPS '75. New York, NY, USA: Association for Computing Machinery. pp. 701–707. doi:10.1145/1499949.1500100. ISBN 978-1-4503-7919-9.
25. Cerf, V.; Kahn, R. (1974). "A Protocol for Packet Network Intercommunication" (PDF). IEEE Transactions on Communications. 22 (5): 637–648. doi:10.1109/TCOM.1974.1092259. ISSN 1558-0857. 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.
26. Specification of Internet Transmission Control Program. 1974. doi:10.17487/RFC0675. RFC 675.
27. J. Day. How in the Heck Do You Lose a Layer!? 2nd IFIP International Conference of the Network of the Future, Paris, France, 2011
28. Russell, Andrew L. (2014). Open standards and the digital age: history, ideology, and networks. New York: Cambridge Univ Press. p. 196. ISBN 978-1107039193.
29. Day, John (2007-12-27). Patterns in Network Architecture: A Return to Fundamentals (paperback): A Return to Fundamentals. Pearson Education. ISBN 978-0-13-270456-4.
30. Cerf, V.; McKenzie, A; Scantlebury, R; Zimmermann, H (1976). "Proposal for an international end to end protocol". ACM SIGCOMM Computer Communication Review. 6: 63–89. doi:10.1145/1015828.1015832. S2CID 36954091.
31. Davies, Donald Watts (1979). Computer Networks and Their Protocols. Wiley. p. 468. ISBN 978-0-471-99750-4.
32. Esmailzadeh, Riaz (2016-03-04). Broadband Telecommunications Technologies and Management. John Wiley & Sons. ISBN 978-1-118-99565-5.
33. "Hubert Zimmerman". www.historyofcomputercommunications.info. Retrieved 2020-08-27.
34. by Vinton Cerf, as told to Bernard Aboba (1993). "How the Internet Came to Be". Retrieved 27 November 2022. We began doing concurrent implementations at Stanford, BBN, and University College London. So effort at developing the Internet protocols was international from the beginning.
35. "The internet's fifth man". Economist. 13 December 2013. Retrieved 11 September 2017. 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.
36. Barber, D., and J. Laws, "A Basic Mail Scheme for EIN," INWG 192, February 1979.
37. IEN 85.
38. Sunshine, Carl (January 1987). "IFIP WG 6.1 Newsletter 87/1". umedia.lib.umn.edu. Retrieved 2024-07-09.
39. Sunshine, Carl A., ed. (1989). "A Brief History of Computer Networking". Computer network architectures and protocols. Applications of communications theory (2nd ed.). New York: Plenum Press. pp. 3–6. ISBN 978-0-306-43189-0.
40. Russell, Andrew L. "Rough Consensus and Running Code' and the Internet-OSI Standards War" (PDF). IEEE Annals of the History of Computing.
41. Davies, Howard; Bressan, Beatrice (2010-04-26). A History of International Research Networking: The People who Made it Happen. John Wiley & Sons. ISBN 978-3-527-32710-2.
42. Hempstead, C.; Worthington, W., eds. (2005). Encyclopedia of 20th-Century Technology. Vol. 1, A–L. Routledge. p. 574. ISBN 9781135455514. The network research community formed the [International] Network Working Group (INWG) ... and out of this came the ... transmission control protocol/internet protocol (TCP/IP)
43. "Vinton G. Cerf : An Oral History". Stanford Oral History Collections - Spotlight at Stanford. 2020. p. 84. Retrieved 2024-06-29.

Primary sources

In chronological order:

• Cerf, Vinton (editor) (June 1973), International Transmission Protocol, IFIP WG6.1, INWG 28.
• Cerf, Vinton; Kahn, Robert (September 1973), Host and Process Level Protocols for Internetwork Communication, IFIP WG6.1, INWG 39.
• Pouzin, Louis (October 1973), Interconnection of Packet Switching Networks, IFIP WG6.1, INWG 42.
• Zimmermann, Hubert; Elie, Michel (December 1973), Proposed Standard Host-Host Protcol for Heterogenous Computer Networks: Transport Protocol, IFIP WG6.1, INWG 43.
• Pouzin, Louis (March 1974), A Proposal for Interconnecting Packet Switching Networks, IFIP WG6.1, INWG 60.
• Zimmermann, Hubert; Elie, Michel (April 1974), Transport Protocol: Standard Host-Host Protocol for Heterogeneous Computer Networks, IFIP WG6.1, INWG 61.
• Cerf, Vinton; Kahn, Robert (May 1974). "A Protocol for Packet Network Intercommunication". IEEE Transactions on Communications. 22 (5): 637–648. doi:10.1109/TCOM.1974.1092259.
• Pouzin, Louis (May 1974), A Proposal for Interconnecting Packet Switching Networks, Proceedings of EUROCOMP, Brunel University, pp. 1023-36.
• McKenzie, Alex (December 1974), Internetwork Host-to-Host Protocol, IFIP WG6.1, INWG 74.
• Pouzin, Louis (May 1975). "An integrated approach to network protocols". Proceedings of the May 19-22, 1975, national computer conference and exposition on - AFIPS '75. Association for Computing Machinery. pp. 701–707. doi:10.1145/1499949.1500100. ISBN 978-1-4503-7919-9.
• Cerf, Vinton; McKenzie, Alex; Scantlebury, Roger; Zimmermann, Hubert (July 1975), Proposal for an Internetwork End-to-End Protocol, IFIP WG6.1, INWG 96.
• Cerf, V.; McKenzie, A; Scantlebury, R; Zimmermann, H (1976). "Proposal for an international end to end protocol". ACM SIGCOMM Computer Communication Review. 6: 63–89. doi:10.1145/1015828.1015832. S2CID 36954091.

Further reading

• Kerssens, Niels (2019-12-13). "Rethinking legacies in internet history: Euronet, lost (inter)networks, EU politics". Internet Histories. 4: 32–48. doi:10.1080/24701475.2019.1701919. ISSN 2470-1475.
• Kim, Byung-Keun (2005). Internationalizing the Internet: The Co-evolution of Influence and Technology. Edward Elgar Publishing. ISBN 978-1-84542-675-0.
• Russell, Andrew L. (2014). Open Standards and the Digital Age: History, Ideology, and Networks. Cambridge University Press. ISBN 978-1-139-91661-5.

External links

• International Packet Network Working Group (INWG), Charles Babbage Institute Archives, University of Minnesota Archival Collection