Protocol Wars - Knowledge

1264:. IP was the second most popular set of protocols with 20% of traffic, attributed to UNIX machines for which "IP is the natural choice". Paul Bryant, Head of Communications and Small Systems at RAL, wrote "Experience has shown that IP systems are very easy to mount and use, in contrast to such systems as SNA and to a lesser extent X.25 and Coloured Books where the systems are rather more complex." The author continued "The principal network within the USA for academic traffic is now based on IP. IP has recently become popular within Europe for inter-site traffic and there are moves to try and coordinate this activity. With the emergence of such a large combined USA/Europe network there are great attractions for UK users to have good access to it. This can be achieved by gatewaying Coloured Book protocols to IP or by allowing IP to penetrate the UK. Gateways are well known to be a cause of loss of quality and frustration. Allowing IP to penetrate may well upset the networking strategy of the UK." Similar views were shared by others at the time, including Louis Pouzin. At CERN, Flückiger reflected "The technology is simple, efficient, is integrated into UNIX-type operating systems and costs nothing for the users' computers. The first companies that commercialize routers, such as Cisco, seem healthy and supply good products. Above all, the technology used for local campus networks and research centres can also be used to interconnect remote centers in a simple way." 1181:(EARN) Board of Directors, said "By the time JNT came along we could demonstrate X25… and we firmly believed that BT would provide us with the network infrastructure and we could do away with leased lines and experimental work. If we had gone with DARPA then we would not have expected to be able to use a public service. In retrospect the flaws in that argument are clear but not at the time. Although we were fairly proud of what we were doing, I don't think it was national pride or anti USA that drove us, it was a belief that we were doing the right thing. It was the latter that translated to religious dogma." JANET was a free X.25-based network for academic use, not research; experiments and other protocols were forbidden. 487: 700: 794:, which used X.25. Peter Kirstein wrote that European networks tended to be short-term projects with smaller numbers of computers and users. As a result, the European networking activities did not lead to any strong standards except X.25, which became the main European data protocol for fifteen to twenty years. Kirstein said his group at University College London was widely involved, partly because they were one of the groups with the most expertise, and partly to try to ensure that the British activities, such as the 941:

constraining in the long run. Although dominated by computer manufacturers, they had to contend with many competing priorities and interests. The rate of technological change made it necessary to define a model that new systems could converge to rather than standardizing procedures after the fact; the reverse of the traditional approach to developing standards. Although not a standard itself, it was an architectural framework that could accommodate existing and future standards.

396:

setting up the circuit, meaning that a single packet can be transmitted as efficiently as a long stream. Generally, this makes routing around problems simpler as only the single routing table needs to be updated, not the information for every virtual circuit. It also requires less memory, as only one route needs to be stored for any destination, not one per virtual circuit. On the downside, there is a need to examine every datagram, which makes them (theoretically) slower.

615:, published by Cerf and Kahn in 1974 addressed the fundamental challenges involved in interworking across datagram networks with different characteristics, including routing in interconnected networks, and packet fragmentation and reassembly. The paper drew upon and extended their prior research, developed in collaboration and competition with other American, British and French researchers. DARPA sponsored work to formulate the first version of the 1050: 472:. The routers are also faster as the route setup is only done once; from then on, packets are simply forwarded down the existing link. One downside is that the equipment has to be more complex as the routing information has to be stored for the length of the connection. Another disadvantage is that the virtual connection may take some time to set up end-to-end, and for small messages, this time may be significant. 140: 1034:

scheme. The OSI model reinforced this reinterpretation of X.25's role. Once the concept of a hierarchy of protocols had been accepted, and once TCP, IP, and X.25 had been assigned to different layers in this hierarchy, it became easier to think of them as complementary parts of a single system, and more difficult to view X.25 and the Internet protocols as distinct and competing systems."

149: 3881:"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." 558:(ICCC) in Washington demonstrated the ARPANET. At the ICCC, Pouzin first presented his ideas on internetworking, and Vint Cerf was approved as INWG's Chair on Steve Crocker's recommendation. INWG grew to include other American researchers, members of the French CYCLADES and RCP projects, and the British teams working on the NPL network, EPSS and the proposed 468:. Després simplified and improved on the virtual call approach, introducing the concept of "graceful saturated operation" in 1972. He coined the term "virtual circuit" and validated the concepts on the RCP network. Once set up, the data packets do not have to contain any routing information, which can simplify the packet structure and improve 593:(PUP) for internetworking. INWG met in Stanford in June 1973. Zimmermann and Metcalfe dominated the discussions. Notes from the meetings were recorded by Cerf and Alex McKenzie, from BBN, and published as numbered INWG Notes (some of which were also RfCs). Building on this, Kahn and Cerf presented a paper at a networking conference at the 848:' BNA. By the end of the 1970s, IBM's networking activities were, by some measures, two orders of magnitude larger in scale than the ARPANET. During the late 1970s and most of the 1980s, there remained a lack of open networking options. Therefore, proprietary standards, particularly SNA and DECnet, as well as some variants of XNS (e.g., 431:(FTP), to run functions across the ARPANET. After approval by Barry Wessler at ARPA, who had ordered certain more exotic elements to be dropped, the NCP was finalized and deployed in December 1970 by the NWG. NCP codified the ARPANET network interface, making it easier to establish, and enabling more sites to join the network. 1133:

Crocker said that although they envisaged a hierarchy of protocols in the early 1970s, "If we had only consulted the ancient mystics, we would have seen immediately that seven layers were required." Although some sources say this was an acknowledgement that the four layers of the Internet Protocol Suite were inadequate.

786:, gained some acceptance internationally as the first complete X.25 standard. First defined in 1975, they gave the UK "several years lead over other countries" but were intended as "interim standards" until international agreement was reached. The X.25 standard gained political support in European countries and from the 354: 411:(UCLA) formed a Network Working Group (NWG) that year. He said "While much of the development proceeded according to a grand plan, the design of the protocols and the creation of the RFCs was largely accidental." Under the supervision of Leonard Kleinrock at UCLA, Crocker led other graduate students, including 661:, a commercial packet-switched network in the US, they joined the international effort to standardize a protocol for packet switching based on virtual circuits shortly before it was finalized. With contributions from the French, British, and Japanese PTTs, particularly the work of Rémi Després on RCP and 2271:

He decided to use packet switching as the underlying technology of the Arpanet; it remains central to the function of the internet. And it was Dr. Roberts's decision to build a network that distributed control of the network across multiple computers. Distributed networking remains another foundation

1537:

Alex McKenzie was employed at BBN and worked on the ARPANET project. Hubert Zimmerman was Louis Pouzin's deputy on the CYCLADES project. Derek Barber became chairman of INWG shortly before the submission. He took over from Vint Cerf, who was chair from its inception. Barber was Davies' deputy at the

1132:

Russell notes that Cohen, Postel and others were frustrated with technical aspects of OSI. The model defined seven layers of computer communications, from physical media in layer 1 to applications in layer 7, which was more layers than the network engineering community had anticipated. In 1987, Steve

3407:

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

3055:

The attached is a translation of a paper by Remi Despres. The translation has been supplied by Don Davies of NPL" "Under the title HERMES project, the French PTT Administration undertook the realization of' a new telecommunications network especially for data transmission. It is intended to offer on

1247:

By the beginning of the 1990s, some smaller European countries had adopted TCP/IP. In February 1990, RARE stated "without putting into question its OSI policy, recognizes the TCP/IP family of protocols as an open multivendor suite, well adapted to scientific and technical applications." In the same

1232:

made a speech at a technical conference entitled "Is OSI Too Late?" which received a standing ovation. OSI was formally defined, but vendor products from computer manufactures and network services from PTTs were still to be developed. TCP/IP by comparison was not an official standard (it was defined

395:

Datagram services include the information needed for looking up the next link in the network in every packet. In these systems, routers examine each arriving packet, look at their routing information, and decide where to route it. This approach has the advantage that there is no inherent overhead in

380:

are possible). With a virtual circuit service, data can be exchanged between two host applications only after a virtual circuit has been established between them in the network. After that, flow control is imposed to sources, as much as needed by destinations and intermediate network nodes. Data are

2021:

As Kahn recalls: ... Paul Baran's contributions ... I also think Paul was motivated almost entirely by voice considerations. If you look at what he wrote, he was talking about switches that were low-cost electronics. The idea of putting powerful computers in these locations hadn't quite occurred to

1437:

In his many publications on the "histories of networking", Andrew L. Russell argues scholars could and should look differently at the history of the Internet. His work shifts scholarly and popular understanding about the origins of the Internet and contemporary work in Europe that both competed and

1252:

in the United States. Conversely, starting in August 1990, the NSFNET backbone supported the OSI CLNP in addition to TCP/IP. CLNP was demonstrated in production on NSFNET in April 1991, and OSI demonstrations, including interconnections between US and European sites, were planned at the Interop '91

1241:

said "it has not been worth the ten years wait to get from TCP to TP4, but OSI is now inevitable" and Sunshine expected "OSI architecture and protocols ... will dominate in the future." The following year, in 1990, Cerf said: "You can't pick up a trade press article anymore without discovering that

1144:

Richard des Jardins, an early contributor to the OSI reference model, captured the intensity of the rivalry in a 1992 article by saying "Let's continue to get the people of good will from both communities to work together to find the best solutions, whether they are two-letter words or three-letter

1140:

By the early 1980s, the conference circuit became more acrimonious. Carl Sunshine summarized in 1989: "In hindsight, much of the networking debate has resulted from differences in how to prioritize the basic network design goals such as accountability, reliability, robustness, autonomy, efficiency,

1136:

Strict layering in OSI was viewed by Internet advocates as inefficient and did not allow trade-offs ("layer violation") to improve performance. The OSI model allowed what some saw as too many transport protocols (five compared with two for TCP/IP). Furthermore, OSI allowed for both the datagram and

653:

network to change from a datagram to virtual circuit approach, although historians attribute this to IBM's rejection of their request for modification to their proprietary protocol. Pouzin was outspoken in his advocacy for datagrams and attacks on virtual circuits and monopolies. He spoke about the

2570:

three parameters uniquely specify a connection between source and destination Hosts." "The destination IMP returns a positive acknowledgment for receipt of the message to the source IMP, which in turn passes this acknowledgment to the source Host." "Each link is unidirectional and is controlled by

1064:

Historian Andrew L. Russell wrote that Internet engineers such as Danny Cohen and Jon Postel were accustomed to continual experimentation in a fluid organizational setting through which they developed TCP/IP. They viewed OSI committees as overly bureaucratic and out of touch with existing networks

1033:

explained: "by running TCP/IP over X.25, ARPA reduced the role of X.25 to providing a data conduit, while TCP took over responsibility for end-to-end control. X.25, which had been intended to provide a complete networking service, would now be merely a subsidiary component of ARPA's own networking

969:

The DoD model and other existing protocols, such as X.25 and SNA, all quickly adopted a layered approach in the late 1970s. Although the OSI model shifted power away from the PTTs and IBM towards smaller manufacturer and users, the "strategic battle" remained the competition between the ITU's X.25

648:

magazine which ran a story on the "battle for access standards" between datagrams and virtual circuits, as well as a piece describing the "lack of standard access interfaces for emerging public packet-switched communication networks is creating 'some kind of monster' for users". At the conference,

635:

A protocol for internetworking was also being pursued by INWG. There were two competing proposals, one based on the early Transmission Control Program proposed by Cerf and Kahn (using fragmentable datagrams), and the other based on the CYCLADES transport protocol proposed by Pouzin, Zimmermann and

4444:

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

1968:

Then in June 1966, Davies wrote a second internal paper, "Proposal for a Digital Communication Network" In which he coined the word packet,- a small sub part of the message the user wants to send, and also introduced the concept of an "Interface computer" to sit between the user equipment and the

1192:

mandated compliance with the OSI model and the Department of Defense planned to transition away from TCP/IP to OSI. Carl Sunshine wrote in 1989 that "by the mid-1980s ... serious performance problems were emerging , and it was beginning to look like the critics of "stateless" datagram networking

2064:

Paul Baran ... focused on the routing procedures and on the survivability of distributed communication systems in a hostile environment, but did not concentrate on the need for resource sharing in its form as we now understand it; indeed, the concept of a software switch was not present in his

1242:

somebody is doing something with TCP/IP, almost in spite of the fact that there has been this major effort to develop international standards through the international standards organization, the OSI protocol, which eventually will get there. It's just that they are taking a lot of time.".

1237:) but UNIX workstations with both Ethernet and TCP/IP included had been available since 1983 and now served as a de facto interoperability standard. Carl Sunshine notes that "research is underway on how to optimize TCP/IP performance over variable delay and/or very-high-speed networks" However, 673:

Larry Roberts adopted X.25 on Telenet and found that "datagram packets are now more expensive than VC packets" in 1978. Vint Cerf said Roberts turned down his suggestion to use TCP when he built Telenet, saying that people would only buy virtual circuits and he could not sell datagrams. Roberts

4562:

We are screwing up in our design of internet protocols by violating the principle of layering. Specifically we are trying to use TCP to do two things: serve as a host level end to end protocol, and to serve as an internet packaging and routing protocol. These two things should be provided in a

687:

to connect between two networks. At the National Physical Laboratory in the UK, Davies' team studied the "basic dilemma" involved in interconnecting networks: a common host protocol requires restructuring existing networks that use different protocols. To explore this dilemma, the NPL network

1433:

and networking, particularly in highlighting the role of social dynamics and of non-American participation in early networking development. The book was also praised for its use of archival resources to tell the history. She has since written about the need for historians to be aware of the

940:

as chairman, played a key role in the development of the Open Systems Interconnections reference model. They considered it too early to define a set of binding standards while technology was still developing since irreversible commitment to a particular standard might prove sub-optimal or

688:

connected with the EIN by translating between two different host protocols, that is, using a gateway. Concurrently, the NPL connection to the EPSS used a common host protocol in both networks. NPL research confirmed establishing a common host protocol would be more reliable and efficient.

669:

standard was agreed by the CCITT in 1976. X.25 virtual circuits were easily marketed because they permit simple host protocol support. They also satisfy the INWG expectation of 1972 that each subnetwork can exercise its own protection against congestion (a feature missing with datagrams).

1518:

Left to right: Bernard Jamet (France), Masao Kato (Japan), Paul Guinaudeau (France), Claude Martel (Canada), Vern MacDonald (Canada), Rémi Després (France), Halvor Bothner-by (Norway), Philip Kelly (United Kingdom), F. Ishino (Japan), Anton Rybczynski (Canada), Larry Roberts (United

542:

for achieving reliable error and flow control on end-to-end connections. However, the sliding window scheme was never implemented on the CYCLADES network and it was never interconnected with other networks (except for limited demonstrations using traditional telegraphic techniques).

1651:

FIPS 146-2 allowed "...other specifications based on open, voluntary standards such as those cited in paragraph 3 ("...such as those developed by the Internet Engineering Task Force (IETF)... and the International Telecommunications Union, Telecommunication Standardization Sector

932:

publication 'Why Distributed Computing', which was based on extensive research into future potential configurations for computer systems, resulted in the UK presenting the case for an international standards committee to cover this area at the ISO meeting in Sydney in March 1977.

116:

to incorporate TCP/IP software into various operating systems laid the foundation for the widespread adoption of TCP/IP as a comprehensive protocol suite. While OSI developed its networking standards in the late 1980s, TCP/IP came into widespread use on multi-vendor networks for

565:

Bob Kahn joined the IPTO in late 1972. Although initially expecting to work in another field, he began work on satellite packet networks and ground-based radio packet networks, and recognized the value of being able to communicate across both. In Spring 1973, Vint Cerf moved to

5009:

Two main approaches to internetworking have come into existence based upon the virtual circuit and the datagram services. The vast majority of the work on interconnecting networks falls into one of these two approaches: The CCITT X.75 Recommendation; The DoD Internet Protocol

1412:

1996) explores the "human dimension" of the development of the ARPANET covering the "theorists, computer programmers, electronic engineers, and computer gurus who had the foresight and determination to pursue their ideas and affect the future of technology and society".

1105:

Furthermore, the Internet community was opposed to a homogeneous approach to networking, such as one based on a proprietary standard such as SNA. They advocated for a pluralistic model of internetworking where many different network architectures could be joined into a

970:

and proprietary standards, particularly SNA. Neither were fully OSI compliant. Proprietary protocols were based on closed standards and struggled to adopt layering while X.25 was limited in terms of speed and higher-level functionality that would become important for

990:(ICCB) in 1979 to oversee the network's architectural evolution and field technical questions. However, DARPA was still in control and, outside the nascent Internet community, TCP/IP was not even a candidate for universal adoption. The implementation in 1985 of the 2234:

Mr. Taylor wrote a white paper in 1968, a year before the network was created, with another ARPA research director, J. C. R. Licklider. The paper, "The Computer as a Communications Device," was one of the first clear statements about the potential of a computer

307:(IMPs). Roger Scantlebury presented Davies' work on a digital communication network and referenced the work of Paul Baran. At this seminal meeting, the NPL paper articulated how the data communications for such a resource-sharing network could be implemented. 1434:

perspectives they take in writing about the history of the Internet and explored the implications of defining the Internet in terms of "technology, use and local experience" rather than through the lens of the spread of technologies from the United States.

2806:

Simple best-effort traffic, as implemented in the current Internet, makes minimal technical demands on the infrastructure." "there are well-known problems with the enforcement of fairness and the avoidance of congestion collapse with simple best-effort

674:

predicted that "As part of the continuing evolution of packet switching, controversial issues are sure to arise." Pouzin remarked that "the PTT's are just trying to drum up more business for themselves by forcing you to take more service than you need."

1156:

described the "Architectural Principles of the Internet" by saying "in very general terms, the community believes that the goal is connectivity, the tool is the Internet Protocol, and the intelligence is end to end rather than hidden in the network."

1937:

Almost immediately after the 1965 meeting, Davies conceived of the details of a store-and-forward packet switching system. ... In nearly all respects, Davies' original proposal, developed in late 1965, was similar to the actual networks being built

3908:

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

1275:

traffic on the existing network. Within eight months, the IP traffic had exceeded the levels of X.25 traffic, and the IP support became official in November. Also in 1991, Dai Davies introduced Internet technology over X.25 into the pan-European

341:(although this was not end-to-end). With the constraint that, for each connection, only one message may be in transit in the network, the sequential order of messages is preserved end-to-end. This made the ARPANET what would come to be called a 2444:

The NPL group influenced a number of American computer scientists in favor of the new technique, and they adopted Davies's term "packet switching" to refer to this type of network. Roberts also adopted some specific aspects of the NPL

915:

for data networks and protocols culminated in the Internet–OSI Standards War in the 1980s and early 1990s. Engineers, organizations and nations became polarized over the issue of which standard would result in the best and most robust

4932:

Council, National Research; Sciences, Division on Engineering and Physical; Board, Computer Science and Telecommunications; Applications, Commission on Physical Sciences, Mathematics, and; Committee, NII 2000 Steering (1998-02-05).

960:

The most fundamental idea of the OSI model was that of a "layered" architecture. The layering concept was simple in principle but very complex in practice. The OSI model redefined how engineers thought about network architectures.

654:"political significance of the controversy," which he saw as "initial ambushes in a power struggle between carriers and the computer industry. Everyone knows in the end, it means IBM vs. Telecommunications, through mercenaries." 1383:

The seven-layer OSI model is still used as a reference for teaching and documentation; however, the OSI protocols conceived for the model did not gain popularity. Some engineers argue the OSI reference model is still relevant to

631:

and Carl Sunshine as a monolithic (single layer) design. The following year, testing began through concurrent implementations at Stanford, BBN and University College London, but it was not installed on the ARPANET at this time.

643:

The fourth biennial Data Communications Symposium later that year included presentations from Davies, Pouzin, Derek Barber, and Ira Cotten about the current state of packet-switched networking. The conference was covered by

4222:

the existing packet-switch networks, based on virtual circuit-switching, of course don't have this kind of type of congestion problem in quite the same way. The congestion problem is solved, in my view, in a rather cruder

1499:

Crocker said "NCP" later came to be used as the name for the protocol , but it originally meant the program within the operating system that managed connections. The protocol itself was known blandly only as the host-host

1338:

the following year. NSFNET had altered its policies to allow commercial traffic in 1991, and was shut down in 1995, removing the last restrictions on the use of the Internet to carry commercial traffic. Subsequently, the

1081:(IETF) meeting, revealing a T-shirt emblazoned with "IP on Everything". According to Cerf, his intention was to reiterate that a goal of the IAB was to run IP on every underlying transmission medium. At the same meeting, 1371:

is leading to the connection of new types of devices to the Internet, bringing reality to Cerf's vision of "IP on Everything". Nonetheless, shortcomings exist with today's Internet; for example, insufficient support for

2022:

him as being cost effective. So the idea of computer switches was missing. The whole notion of protocols didn't exist at that time. And the idea of computer-to-computer communications was really a secondary concern.

723:. Bob Kahn's efforts led to the absorption of MIT's proposal by Dave Clark and Dave Reed for a Data Stream Protocol (DSP) into version 3 of TCP in January 1978 written by Cerf, now at DARPA, and Jon Postel at the 682:

Internetworking protocols were still in their infancy. Various groups, including ARPA researchers, the CYCLADES team, and others participating in INWG, were researching the issues involved, including the use of

530:. The network used unreliable, standard-sized, datagrams in the packet-switched network and virtual circuits for the transport layer. First demonstrated in 1973, it pioneered the use of the pure datagram model, 6725:

Super-linear routing table growth, high update churn, lack of mobility and security, insufficient support for multi-homing and traffic engineering are some of the significant deficiencies of today's Internet.

5815: 6893:

The protocol wars that were waged into the late 20th century are over, and the winner for now is IP (Internet Protocol). Though not relegated to the dustbin, contenders such as X.25 and SNA have become niche

6429:

American Countercultures: An Encyclopedia of Nonconformists, Alternative Lifestyles, and Radical Ideas in US History: An Encyclopedia of Nonconformists, Alternative Lifestyles, and Radical Ideas in US History

982:

criticised "zealous" advocates of the OSI reference model and criticised the functionality of the X.25 protocol and its use as an ""end-to-end" protocol in the sense of a Transport or Host-to-Host protocol".

954: 225:

Baran published a series of papers between 1960 and 1964 about dividing information into "message blocks" and dynamically routing them over distributed networks. Davies conceived of and named the concept of

944:

Beginning in 1978, international work led to a draft proposal in 1980. In developing the proposal, there were clashes of opinions between computer manufacturers and PTTs, and of both against IBM. The final

1303:(GOSIP), developed in the late 1980s and early 1990s, would have led to X.400 adoption. Proprietary commercial systems offered an alternative. In practice, use of the Internet suite of email protocols ( 6481:"60 FR 25888 - APPROVAL OF FEDERAL INFORMATION PROCESSING STANDARDS PUBLICATIONS (FIPS) 146-2, PROFILES FOR OPEN SYSTEMS INTERNETWORKING TECHNOLOGIES, AND 179-1, GOVERNMENT NETWORK MANAGEMENT PROFILE" 1096:) that first evolved during the work on the ARPANET was as important as the technical developments in enabling the governance of the Internet to adapt to the scale and challenges involved as it grew. 1288:

became operational in 1992. OSI usage on the NSFNET remained low when compared to TCP/IP. In the UK, the JANET community talked about a transition to OSI protocols, which was to begin with moving to

66:. As more of these networks emerged in the mid to late 1970s, the debate about communication protocols became a "battle for access standards". An international collaboration between several national 3891: 707:

The design of the Transmission Control Program incorporated both connection-oriented links and datagram services between hosts. A DARPA internetworking experiment in July 1977 linking the ARPANET,

763:

in March and Peter Kirstein's group at UCL in November. On January 1, 1983, known as "flag day", TCP/IP was installed on the ARPANET. This resulted in a networking model that became known as the

1444:

and Valérie Schafer have focused on British and French contributions as well as global and international considerations in the development of packet switching, internetworking and the Internet.

597:

in England in September 1973. Their ideas were refined further in long discussions with Davies, Scantlebury, Pouzin and Zimmerman. Most of the work was done by Kahn and Cerf working as a duet.

907:

illustrated that "some people foresaw a division between world technologies: Internet in the United States, OSI in Europe. In this model, the two sides would have communicated via gateways."

691:

The CYCLADES project, however, was shut down in the late 1970s for budgetary, political and industrial reasons and Pouzin was "banished from the field he had inspired and helped to create".

814:

standard, which enabled internetworking across national PTT networks in Europe and commercial networks in North America, this led to a global infrastructure for commercial data transport.

920:. Both standards are open and non-proprietary in addition to being incompatible, although "openness" may have worked against OSI while being successfully employed by Internet advocates. 900: 522:, and others. While building the network, they were advised by BBN as consultants. Pouzin's team was the first to tackle the highly-complex problem of providing user applications with a 1419:

suggested in 1998 that no one single account of the history of the Internet is sufficient and there will need to be a more adequate history written that includes aspects of many books.

2547:

I actually wrote the technical part of the proposal." "One of the problems Kahn faced in building the IMPs was others' confidence that message packet congestion would not be a problem.

636:

Elie (using standard-sized datagrams). A compromise was agreed and Cerf, McKenzie, Scantlebury and Zimmermann authored an "international" end-to-end protocol. It was presented to the

269:(PTT). They both believed speech traffic would continue to dominate and continued to invest in traditional telegraphic techniques. Telephone companies were operating on the basis of 570:. With funding from DARPA, he began collaborating with Kahn on a new protocol to replace NCP and enable internetworking. Cerf built a research team at Stanford studying the use of 1326:

at CERN, as an application on the Internet, brought many social and commercial uses to what was previously a network of networks for academic and research institutions. The Web

562:(EIN), a datagram network. Like Baran in the mid-1960s, when Roberts approached AT&T about taking over the ARPANET to offer a public packet-switched service, they declined. 384:

Both concepts have advantages and disadvantages depending on their application domain. Where a best effort service is acceptable, an important advantage of datagrams is that a

3952:

We began doing concurrent implementations at Stanford, BBN, and University College London. So effort at developing the Internet protocols was international from the beginning.

6324: 1102:

wrote that "firms that win the Internet market, like Cisco, are small. Simply, they possess the Internet culture, are interested in it and, notably, participate in IETF."

392:. In addition, for users of the best effort service, use of network resources does not enforce any definition of "fairness"; that is, relative delay among user classes. 1141:

and cost effectiveness. Higher priority on robustness and autonomy led to the DoD Internet design, while the PDNs have emphasized accountability and controllability."

3005: 1509:

The NPL team also envisaged the need for levels of data transmission in 1968. Both were early examples of the protocol layering concept incorporated in the OSI model.

453: 6254: 4831: 1438:

cooperated with the push for TCP/IP. James Pelkey conducted interviews with Internet pioneers in the late 1980s and completed his book with Andrew Russell in 2022.

4202:

A network must be able to protect itself against congestion without depending completely on the correct operation of other networks with which it is interconnected

4445:

working group meetings in 1976 and 1977, suggesting the possible benefits of separating TCPs routing and transmission control functions into two discrete layers.

3390: 3069: 490:

Key contributors to X.25, just after its approval in March 1976, including engineers from three PTTs (France, Japan, UK) and two private companies (Canada, US)

1718:

The first packet-switching network was implemented at the National Physical Laboratories in the United Kingdom. It was quickly followed by the ARPANET in 1969.

364:

Packet switching can be based on either a connectionless or connection-oriented mode, which are different approaches to data communications. A connectionless

3895: 1564:

Participants in the design of X.25 included engineers from Canada (DATAPAC), France (the PTT), Japan (NTT), the UK (the Post Office), and the US (Telenet).

457: 3046: 1762:"Paul Baran, an engineer celebrated as the co-inventor (along with Davies) of the packet switching technology that is the foundation of digital networks" 555: 6500: 4099:

Mathison, Stuart L.; Roberts, Lawrence G.; Walker, Philip M. (2012). "The history of telenet and the commercialization of packet switching in the US".

4197: 1284:, although he experienced personal opposition to this approach. The EARN and RARE adopted IP around the same time, and the European Internet backbone 3892:"The Computer History Museum, SRI International, and BBN Celebrate the 40th Anniversary of First ARPANET Transmission, Precursor to Today's Internet" 1085:

summarized the IETF approach with the famous saying "We reject: kings, presidents, and voting. We believe in: rough consensus and running code." The

6801: 498:

thought it looked technically feasible to employ a simpler approach to wide-area networking than that of the ARPANET. In 1972, Pouzin launched the

6572: 3714: 7003: 4960: 1600: 1300: 775:. Leonard Kleinrock's theoretical work published in the mid-1970s on the performance of the ARPANET underpinned the development of the protocol. 3097: 1612:

According to one source, Vint Cerf, as program manager for the ARPANET, also denied funding for ARPA contractors to participate in ISO meetings.

5072: 1331: 950: 105:, which was not compatible with TCP/IP, had been agreed upon. Many European governments (particularly France, West Germany and the UK) and the 5558: 5290: 219: 574:

datagrams. Gérard Le Lann joined the team during the period 1973-4 and Cerf incorporated his sliding windows scheme into the research work.

4214: 2607:"Arpanet ... provides only for basic services allowing the transfer of up to 1000 octet messages, with flow control but not error control." 7707:

Cerf, Vinton; McKenzie, Alex; Scantlebury, Roger; Zimmermann, Hubert (January 1976). "Proposal for an international end to end protocol".

3580: 2584: 2218: 6643: 5318: 2945: 295:

into the project; Kleinrock had applied mathematical methods to study communication networks in his doctoral thesis. At the October 1967

4882:

Interlinking of Computer Networks: Proceedings of the NATO Advanced Study Institute held at Bonas, France, August 28 – September 8, 1978

3187: 715:

demonstrated its viability. Subsequently, DARPA and collaborating researchers at Stanford, UCL and BBN, among others, began work on the

6485: 1123: 1029:

DARPA studied and implemented gateways, which helped to neutralize X.25 as a rival networking paradigm. The computer science historian

735:, in version 4 of TCP, first drafted in September 1978, Postel split the Transmission Control Program into two distinct protocols, the 703:

The first demonstration of the Internet, linking DARPA's three networks (the ARPANET, SATNET, and PRNET), which took place in July 1977

502:

project, with cooperation provided by the French PTT, including free lines and modems. He began to research what would later be called

494:

Davies had conceived and described datagram networks, done simulation work on them, and built a single packet switch with local lines.

608:, the first international heterogeneous computer network. By 1975, there were 40 British academic and research groups using the link. 5136: 4907: 1065:

and computers. This alienated the Internet community from the OSI model. A dispute broke out within the Internet community after the

296: 6227: 6027: 5207: 3477: 2479:

Roberts was quick to latch on to a good idea. 'Suddenly I learned how to route packets,' he later said of the Gatlinburg conference.

5889: 5767:

Though the Pentagon oversaw the ARPANET during the years when it was footing the bill for deployment, its power gradually dwindled.

5654: 4578: 1733: 1408:

and Matthew Lyon published one of the earliest in-depth and comprehensive histories of the ARPANET and how it led to the Internet.

1335: 1299:(UUCP) in the 1980s, which was well suited for handling message transfers between machines that were intermittently connected. The 760: 399:

On the ARPANET, the starting point in 1969 for connecting a host computer (i.e., a user) to an IMP (i.e., a packet switch) was the

195: 6332: 7249: 6076: 2593:

Arpanet had its deficiencies, however, for it was neither a true datagram network nor did it provide end-to-end error correction.

1951: 1277: 266: 67: 2409: 2127: 1038: 4435:

Machines and romances: the technical and narrative construction of networked computing as a general-purpose platform, 1960–1995

2510: 2012: 1388:. Others say the original OSI model doesn't fit today's networking protocols and have suggested instead a simplified approach. 1334:

proposed in 1994 that GOSIP should incorporate TCP/IP and drop the requirement for compliance with OSI, which was adopted into

1209: 1178: 6375:

Great Projects: The Epic Story of the Building of America, from the Taming of the Mississippi to the Invention of the Internet

5943: 27:

that occurred from the 1970s to the 1990s, when engineers, organizations and nations became polarized over the issue of which

7854: 7835: 7787: 7697: 7474: 7455: 7434: 7413: 7380: 7276: 6886: 6710: 6609: 6437: 6410: 6402:

Electronic Commerce Management for Business Activities and Global Enterprises: Competitive Advantages: Competitive Advantages

6383: 6198: 6060: 5873: 5593: 5541: 5474: 5447: 5404: 5368: 5146: 4944: 4890: 4863: 4338: 4055:

Cerf, V.; McKenzie, A.; Scantlebury, R.; Zimmermann, H. (January 1976). "Proposal for an international end to end protocol".

3995: 3757: 3513: 2371: 803: 408: 2186: 6851: 4652: 4185:

a virtual circuit service is more directly marketable, not requiring substantial modifications to customers' host computer.

3774: 3287:

Després, Rémi (2010). Schwartz, Mischa (ed.). "X.25 Virtual Circuits – TRANSPAC In France – Pre-Internet Data Networking".

3024: 1552: 1327: 987: 106: 101:

was released in 1981 and was made the standard for all DoD computer networking. By 1984, the international reference model

7391: 6242: 4819: 6157: 1759: 1377: 1229: 1185: 547: 203: 94: 6876: 2199: 1022:

in 1989. This laid the foundation for the growth of TCP/IP as a comprehensive protocol suite, which became known as the

888: 4022: 3614:

jamais connecté en packet-switching a aucun autre réseau ... (intégration du sliding window scheme) / jamais implémenté

2472: 1217: 884: 856:), were commonly used on private networks, becoming somewhat "de facto" industry standards. Ethernet, promoted by DEC, 605: 280: 5231: 1177:

machines with TCP/IP for their intranet between 1984 and 1988. Nonetheless, Paul Bryant, the UK representative on the

360:

magazine covered the "Battle for Access Standards" between datagrams and virtual circuits in its October 1975 edition.

257:

Licklider, Baran and Davies all found it hard to convince incumbent telephone companies of the merits of their ideas.

7917: 7353: 6464: 5102: 4398: 3435: 3127: 3056:

this network not only conventional circuit switching with improved performance but also a "packet" switching service.

2540: 2419: 2207:(PhD thesis). Department of Electrical Engineering, Imperial College of Science and Technology, University of London. 1995: 1626: 861: 728: 523: 420: 199: 109:

mandated compliance with the OSI model, while the US Department of Defense planned to transition from TCP/IP to OSI.

97:(DoD) developed TCP/IP during the 1970s in collaboration with universities and researchers in the US, UK and France. 4549: 3798: 2165: 546:

Louis Pouzin's ideas to facilitate large-scale internetworking caught the attention of ARPA researchers through the

7912: 2248: 1312: 1216:, and restricted funding for non-OSI compliant protocols. However, by 1988, the Internet community had defined the 807: 7126: 5758: 1184:

The DARPA Internet was still a research project that did not allow commercial traffic or for-profit services. The

743:(IP) as connectionless service. For applications that did not want the services of TCP, an alternative called the 7485: 5988: 2497: 2146: 1078: 1057: 7287: 4137:

Rybczynski, Tony (December 2009). "Commercialization of packet switching (1975-1985): A Canadian perspective ".

3071:

RCP, the Experimental Packet-Switched Data Transmission Service of the French PTT: History, Connections, Control

2840: 1400: 755:

was made standard for all military computer networking in March 1982. It was installed on SATNET and adopted by

7303:

Campbell-Kelly, Martin; Garcia-Swartz, Daniel D (2013). "The History of the Internet: The Missing Narratives".

6250: 4827: 1260:(RAL) in the United Kingdom in January 1991, DECnet represented 75% of traffic, attributed to Ethernet between 1257: 1056:

emphasized the goal of running "IP on everything", notably with a T-shirt he wore while presenting to the 1992

724: 435: 388:

may be kept very simple. A counterpart is that, under heavy traffic, no subnetwork is per se protected against

5491: 1808: 438:

division (BPO-T) in 1969. There, engineers developed a packet-switching protocol from basic principles for an

6738: 6508: 1463: 1304: 829: 736: 7797:

Rosenzweig, Roy (1998). "Wizards, Bureaucrats, Warriors, and Hackers: Writing the History of the Internet".

2305: 164:

designed the first two packet switching networks for computer-to-computer communication: the NPL Network (a

6668: 1548: 825: 684: 616: 559: 310: 288: 83: 3629: 2331:

Thus the set of IMP's, plus the telephone lines and data sets would constitute a message switching network

1166: 113: 7907: 5802: 5698: 5674:

until Internet (initially ARPANET + TCP/IP) was "demobbed" it was not even a candidate (Abbate 1999, 211)

5627: 4704: 1985: 1066: 876: 787: 486: 304: 4311: 3731: 2393: 1228:, the European UNIX Network, announced its conversion to Internet technology. By 1989, the OSI advocate 7922: 6576: 5642: 4990: 4458: 4173: 3686: 2378:

Historians credit seminal insights to Welsh scientist Donald W. Davies and American engineer Paul Baran

1905: 481: 464:. Its purpose was to put into operation a prototype packet switching service to be offered on a future 6601:

Technologies and Protocols for the Future of Internet Design: Reinventing the Web: Reinventing the Web

3648:

McKenzie, Alexander (January 2011). "INWG and the Conception of the Internet: An Eyewitness Account".

5746: 1468: 1344: 1189: 929: 720: 601: 7870: 5062: 1538:

National Physical Laboratory in the United Kingdom and director of the European Informatics Network.

928:

Researchers in the UK and elsewhere identified the need for defining higher-level protocols. The UK

238:

in 1965–1966. He proposed a national commercial data network in the UK, and designed the local-area

7166: 6299: 4489:'Industrial Legislatures': Consensus Standardization in the Second and Third Industrial Revolutions 4041:'Industrial Legislatures': Consensus Standardization in the Second and Third Industrial Revolutions 2285: 1662: 1201: 191: 43:(TCP/IP) by the mid-1990s when it became the dominant protocol suite through rapid adoption of the 5918: 5466:

Education and Training in Health Informatics in Europe: State of the Art, Guidelines, Applications

2766:

This fairness measure is based on mean end-to-end delays derived from Kleinrock's classical model.

1837: 1490:

began as informal technical notes, "requests for comments", of the Networking Working Group (NWG).

1220:(SNMP) to enable management of network devices (such as routers) on multi-vendor networks and the 1119: 998:

at USC, which enabled network growth by facilitating cross-network access, and the development of

802:

based on the X.25 protocol suite continued through the 1980s; international examples included the

6162: 4330: 3599: 2826: 2703: 1599:

France, West Germany, and the United Kingdom were leading advocates of the OSI model through the

1453: 1364: 1272: 1099: 1023: 904: 779: 662: 539: 443: 40: 3813:

Kirstein, P.T. (1999). "Early experiences with the Arpanet and Internet in the United Kingdom".

3749:

The innovators : how a group of hackers, geniuses, and geeks created the digital revolution

1224:'88 trade show showcased new products for implementing networks based on TCP/IP. The same year, 872:. DEC was an exception among the computer manufactures in supporting the peer-to-peer approach. 6185: 6052: 3453:"Designed for Change: End-to-End Arguments, Internet Innovation, and the Net Neutrality Debate" 1574: 999: 744: 428: 243: 28: 7888: 7682:

Proceedings of the May 19-22, 1975, national computer conference and exposition on - AFIPS '75

6907: 6647: 6427: 6373: 5731: 5464: 5255: 5194: 5141:. Applications of communications theory (2nd ed.). New York: Plenum Press. pp. 3–6. 5022:

Unsoy, Mehmet S.; Shanahan, Theresa A. (1981). "X.75 internetworking of Datapac and Telenet".

4934: 4012: 3985: 3972: 3421: 3247: 1629:); Spain; Ireland; Switzerland, and Austria had adopted TCP/IP by the beginning of the decade. 7332: 7211:

Russell, Andrew L. (2017). "Hagiography, revisionism & blasphemy in Internet histories".

6939:"Virtual Machines, Virtual Infrastructures: The New Historiography of Information Technology" 6187:

The history of NORDUnet: twenty-five years of networking cooperation in the noridic countries

6128: 5863: 5583: 5437: 5067: 4880: 4853: 4803: 3503: 3214:

DATACOMM '73: Proceedings of the third ACM symposium on Data communications and Data networks

2621: 2464: 2441: 2361: 1441: 1292:

mail as the first step, but this never happened. The X.25 service was closed in August 1997.

845: 841: 747:(UDP) was added in order to provide direct access to the basic service of IP. Referred to as 590: 6599: 6454: 6400: 5347: 4977: 4785: 4324: 3940: 1741:

Arpanet was virtual circuit." "essentially a virtual circuit service using internal datagram

283:

became the director of the IPTO in 1966 and set out to achieve Licklider's vision to enable

7655:

Cerf, Vinton; Kahn, Robert (May 1974). "A Protocol for Packet Network Intercommunication".

7580:"In the Shadow of ARPANET and Internet: Louis Pouzin and the Cyclades Network in the 1970s" 6480: 6349: 6275: 6002: 5239:

Student Project at Department of Computer Science and Engineering, University of Washington

4631: 4253: 3747: 3337:"In the Shadow of ARPANET and Internet: Louis Pouzin and the Cyclades Network in the 1970s" 2988: 2912: 2819: 2798: 2562: 1487: 1430: 1308: 1234: 1127: 971: 818: 791: 594: 535: 439: 373: 79: 6878:

Breaking the Availability Barrier II: Achieving Century Uptimes with Active/Active Systems

4463:

Entrepreneurial Capitalism and Innovation: A History of Computer Communications, 1968–1988

3452: 8: 7087:

Abbate, Janet (2017). "What and where is the Internet? (Re)defining Internet histories".

6686:

Feldmann, Anja; Cittadini, Luca; Mühlbauer, Wolfgang; Bush, Randy; Maennel, Olaf (2009).

6032: