Packet switching

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In telecommunications, packet switching is a method of grouping data into short messages in fixed format, i.e., packets, that are transmitted over a telecommunications network. Packets consist of a header and a payload. Data in the header is used by networking hardware to direct the packet to its destination, where the payload is extracted and used by an operating system, application software, or higher layer protocols. Packet switching is the primary basis for data communications in computer networks worldwide.

Contents

During the early 1960s, American engineer Paul Baran developed a concept he called distributed adaptive message block switching as part of a research program at the RAND Corporation, funded by the United States Department of Defense. His proposal was to provide a fault-tolerant, efficient method for communication of voice messages using low-cost hardware to route the message blocks across a distributed network. His ideas contradicted then-established principles of pre-allocation of network bandwidth, exemplified by the development of telecommunications in the Bell System. The new concept found little resonance among network implementers until the independent work of British computer scientist Donald Davies at the National Physical Laboratory beginning in 1965. Davies developed the concept for data communication using software switches in a high-speed computer network and coined the term packet switching. His work inspired numerous packet switching networks in the decade following, including the incorporation of the concept into the design of the ARPANET in the United States and the CYCLADES network in France. The ARPANET and CYCLADES were the primary precursor networks of the modern Internet.

Concept

This animation illustrates a network model in which consecutive packets between hosts take differing routes. Out-of-order delivery is, however, detrimental to the performance of several network protocols, including TCP, so the Internet attempts to route packets associated with the same data stream along the same path most of the time. Packet Switching.gif
This animation illustrates a network model in which consecutive packets between hosts take differing routes. Out-of-order delivery is, however, detrimental to the performance of several network protocols, including TCP, so the Internet attempts to route packets associated with the same data stream along the same path most of the time.

A simple definition of packet switching is:

The routing and transferring of data by means of addressed packets so that a channel is occupied during the transmission of the packet only, and upon completion of the transmission the channel is made available for the transfer of other traffic. [2] [3]

Packet switching allows delivery of variable bit rate data streams, realized as sequences of short messages in fixed format, i.e. packets , over a computer network which allocates transmission resources as needed using statistical multiplexing or dynamic bandwidth allocation techniques. As they traverse networking hardware, such as switches and routers, packets are received, buffered, queued, and retransmitted (stored and forwarded), resulting in variable latency and throughput depending on the link capacity and the traffic load on the network. Packets are normally forwarded by intermediate network nodes asynchronously using first-in, first-out buffering, but may be forwarded according to some scheduling discipline for fair queuing, traffic shaping, or for differentiated or guaranteed quality of service, such as weighted fair queuing or leaky bucket. Packet-based communication may be implemented with or without intermediate forwarding nodes (switches and routers). In case of a shared physical medium (such as radio or 10BASE5), the packets may be delivered according to a multiple access scheme.

Packet switching contrasts with another principal networking paradigm, circuit switching, a method which pre-allocates dedicated network bandwidth specifically for each communication session, each having a constant bit rate and latency between nodes. In cases of billable services, such as cellular communication services, circuit switching is characterized by a fee per unit of connection time, even when no data is transferred, while packet switching may be characterized by a fee per unit of information transmitted, such as characters, packets, or messages.

A packet switch has four components: input ports, output ports, routing processor, and switching fabric. [4]

History

Invention and development

The "message block", designed by Paul Baran in 1962 and refined in 1964, is the first proposal of a data packet. The idea of the data packet (Baran, 1964)-en.svg
The "message block", designed by Paul Baran in 1962 and refined in 1964, is the first proposal of a data packet.
Packet-switching cost performance trends, 1960-1980. Packet-switching cost performance trends, 1960-1980.svg
Packet-switching cost performance trends, 1960-1980.

The concept of switching small blocks of data was first invented independently by Paul Baran at the RAND Corporation during the early 1960s in the US and Donald Davies at the National Physical Laboratory (NPL) in the UK in 1965. [8] [9] [10] [11]

In the late 1950s, the US Air Force established a wide area network for the Semi-Automatic Ground Environment (SAGE) radar defense system. Recognizing vulnerabilities in this network, the Air Force sought a system that might survive a nuclear attack to enable a response, thus diminishing the attractiveness of the first strike advantage by enemies (see Mutual assured destruction). In the early 1960s, Baran invented the concept of distributed adaptive message block switching in support of the Air Force initiative. [12] [13] The concept was first presented to the Air Force in the summer of 1961 as briefing B-265, [14] later published as RAND report P-2626 in 1962, [5] and finally in report RM 3420 in 1964. [6] The reports describe a general architecture for a large-scale, distributed, survivable communications network. The proposal was composed of three key ideas: use of a decentralized network with multiple paths between any two points; dividing user messages into message blocks; and delivery of these messages by store and forward switching. [12] [15] Baran's network design was focused on digital communication of voice messages using hardware switches that were low-cost electronics. [16] [17] [18] The ideas were not entirely original to Baran and the task to design a store and forward type of network was formulated by Baran's boss at RAND. [19]

Christopher Strachey, who became Oxford University's first Professor of Computation, filed a patent application in the United Kingdom for time-sharing in February 1959. [20] [21] In June that year, he gave a paper "Time Sharing in Large Fast Computers" at the UNESCO Information Processing Conference in Paris where he passed the concept on to J. C. R. Licklider. [22] [23] Licklider (along with John McCarthy) was instrumental in the development of time-sharing. After conversations with Licklider about time-sharing with remote computers in 1965, [24] [25] Davies independently invented a similar data communication concept. [26] His insight was to use short messages in fixed format with high data transmission rates to achieve rapid communications. [27] He went on to develop a more advanced design for a hierarchical, high-speed computer network including interface computers and communication protocols. [28] [29] [30] He coined the term packet switching, and proposed building a commercial nationwide data network in the UK. [31] [32] He gave a talk on the proposal in 1966, after which a person from the Ministry of Defence (MoD) told him about Baran's work. [33]

Roger Scantlebury, a member of Davies' team, presented their work (and referenced that of Baran) at the October 1967 Symposium on Operating Systems Principles (SOSP). [30] [34] [35] [36] [37] At the conference, Scantlebury proposed packet switching for use in the ARPANET and persuaded Larry Roberts the economics were favorable to message switching. [38] [39] [40] [41] [42] [43] Davies had chosen some of the same parameters for his original network design as did Baran, such as a packet size of 1024 bits. To deal with packet permutations (due to dynamically updated route preferences) and datagram losses (unavoidable when fast sources send to a slow destinations), he assumed that "all users of the network will provide themselves with some kind of error control", [30] thus inventing what came to be known as the end-to-end principle. Davies proposed that a local-area network should be built at the laboratory to serve the needs of NPL and prove the feasibility of packet switching. After a pilot experiment in early 1969, [44] [45] [46] [47] the NPL Data Communications Network began service in 1970. [48] Davies was invited to Japan to give a series of lectures on packet switching. [49] The NPL team carried out simulation work on datagrams and congestion in networks on a scale to provide data communication across the United Kingdom. [47] [50] [51] [52] [53]

Larry Roberts made the key decisions in the request for proposal to build the ARPANET. [54] Roberts met Baran in February 1967, but did not discuss networks. [55] [56] He asked Frank Westervelt to explore the questions of message size and contents for the network, and to write a position paper on the intercomputer communication protocol including “conventions for character and block transmission, error checking and re transmission, and computer and user identification." [57] Roberts revised his initial design, which was to connect the host computers directly, to incorporate Wesley Clark's idea to use Interface Message Processors (IMPs) to create a message switching network, which he presented at SOSP. [58] [59] [60] [61] Roberts was known for making decisions quickly. [62] Immediately after SOSP, he incorporated Davies' concepts and designs for packet switching to enable the data communications on the network, [40] [63] [64] [65] and sought input from Baran. [66]

A contemporary of Roberts' from MIT, Leonard Kleinrock had researched the application of queueing theory in the field of message switching for his doctoral dissertation in 1961–62 and published it as a book in 1964. [67] Davies, in his 1966 paper on packet switching, [28] applied Kleinorck's techniques to show that "there is an ample margin between the estimated performance of the [packet-switched] system and the stated requirement" in terms of a satisfactory response time for a human user. [68] This addressed a key question about the viability of computer networking. [69] Larry Roberts brought Kleinrock into the ARPANET project informally in early 1967. [70] Roberts and Taylor recognized the issue of response time was important, but did not apply Kleinrock's methods to assess this and based their design on a store-and-forward system that was not intended for real-time computing. [71] After SOSP, and after Roberts' direction to use packet switching, [63] Kleinrock sought input from Baran and proposed to retain Baran and RAND as advisors. [72] [73] [74] The ARPANET working group assigned Kleinrock responsibility to prepare a report on software for the IMP. [75] In 1968, Roberts awarded Kleinrock a contract to establish a Network Measurement Center (NMC) at UCLA to measure and model the performance of packet switching in the ARPANET. [72]

Bolt Beranek & Newman (BBN) won the contract to build the network. Designed principally by Bob Kahn, [76] [77] it was the first wide-area packet-switched network with distributed control. [54] The BBN "IMP Guys" independently developed significant aspects of the network's internal operation, including the routing algorithm, flow control, software design, and network control. [78] [79] The UCLA NMC and the BBN team also investigated network congestion. [76] [80] The Network Working Group, led by Steve Crocker, a graduate student of Kleinrock's at UCLA, developed the host-to-host protocol, the Network Control Program, which was approved by Barry Wessler for ARPA, [81] after he ordered certain more exotic elements to be dropped. [82] In 1970, Kleinrock extended his earlier analytic work on message switching to packet switching in the ARPANET. [83]

The ARPANET was demonstrated at the International Conference on Computer Communication (ICCC) in Washington in October 1972. [84] [85] However, fundamental questions about the design of packet-switched networks remained. [86] [87] [88] [89]

Roberts presented the idea of packet switching to communication industry professionals in the early 1970s. Before ARPANET was operating, they argued that the router buffers would quickly run out. After the ARPANET was operating, they argued packet switching would never be economic without the government subsidy. Baran had faced the same rejection and thus failed to convince the military into constructing a packet switching network in the 1960s. [7]

The CYCLADES network was designed by Louis Pouzin in the early 1970s to study internetworking. [90] [91] [92] It was the first to implement the end-to-end principle of Davies, and make the host computers responsible for the reliable delivery of data on a packet-switched network, rather than this being a service of the network itself. [93] His team was thus first to tackle the highly-complex problem of providing user applications with a reliable virtual circuit service while using a best-effort service, an early contribution to what will be the Transmission Control Protocol (TCP). [94]

Bob Metcalfe and others at Xerox PARC outlined the idea of Ethernet and the PARC Universal Packet (PUP) for internetworking. [95]

In May 1974, Vint Cerf and Bob Kahn described the Transmission Control Program, an internetworking protocol for sharing resources using packet-switching among the nodes. [96] The specifications of the TCP were then published in RFC   675 (Specification of Internet Transmission Control Program), written by Vint Cerf, Yogen Dalal and Carl Sunshine in December 1974. [97]

The X.25 protocol, developed by Rémi Després and others, was built on the concept of virtual circuits. In the mid-late 1970s and early 1980s, national and international public data networks emerged using X.25 which was developed with participation from France, the UK, Japan, USA and Canada. It was complemented with X.75 to enable internetworking. [98]

In the late 1970s, the monolithic Transmission Control Program was layered as the Transmission Control Protocol (TCP), atop the Internet Protocol (IP). Many Internet pioneers developed this into the Internet protocol suite and the associated Internet architecture and governance that emerged in the 1980s. [99] [100] [101] [102] [103] [104]

Leonard Kleinrock carried out theoretical work at UCLA during the 1970s analyzing throughput and delay in the ARPANET. [83] [105] [106] His work on hierarchical routing with student Farouk Kamoun became critical to the operation of the Internet. [107] [108] Kleinrock published hundreds of research papers, [109] [110] which ultimately launched a new field of research on the theory and application of queuing theory to computer networks. [111] [112]

Packet switching was shown to be optimal in the Huffman coding sense in 1978. [113] [114]

For a period in the 1980s and early 1990s, the network engineering community was polarized over the implementation of competing protocol suites, commonly known as the Protocol Wars. It was unclear which of the Internet protocol suite and the OSI model would result in the best and most robust computer networks. [115] [116] [117]

Complementary metal–oxide–semiconductor (CMOS) VLSI (very-large-scale integration) technology led to the development of high-speed broadband packet switching during the 1980s–1990s. [118] [119] [120]

The "paternity dispute"

Roberts claimed in later years that, by the time of the October 1967 SOSP, he already had the concept of packet switching in mind (although not yet named and not written down in his paper published at the conference, which a number of sources describe as "vague"), and that this originated with his old colleague, Kleinrock, who had written about such concepts in his Ph.D. research in 1961-2. [60] [38] [61] [121] [122] In 1997, along with seven other Internet pioneers, Roberts and Kleinrock co-wrote "Brief History of the Internet" published by the Internet Society. [123] In it, Kleinrock is described as having "published the first paper on packet switching theory in July 1961 and the first book on the subject in 1964". Many sources about the history of the Internet began to reflect these claims as uncontroversial facts. This became the subject of what Katie Hafner called a "paternity dispute" in The New York Times in 2001. [124]

In the 1978 special edition of the Proceedings of the IEEE on packet switching, Bob Kahn, the guest editor, wrote that "analysis has had little direct impact on the network design problem". [125] In Roberts' paper on "Packet Switching Economics" for the L.M. Ericsson prize for research in data communications in 1982, he referenced only Davies' 1967 paper for SOSP, not the work of Baran or Kleinrock. [126] Kleinrock's paper for the same prize was titled "Packet Switching Principles". [127]

The disagreement about Kleinrock's contribution to packet switching dates back to a statement made on Kleinrock's profile on the UCLA Computer Science department website sometime in the 1990s. Here, he was referred to as the "Inventor of the Internet Technology". [128] The webpage's depictions of Kleinrock's achievements provoked anger among some early Internet pioneers. [129] The dispute over priority became a public issue after Donald Davies posthumously published a paper in 2001 in which he denied that Kleinrock's work in the early 1960s was related to packet switching, stating "I can find no evidence that he understood the principles of packet switching". Davies also described ARPANET project manager Larry Roberts as supporting Kleinrock, referring to Roberts' writings online and Kleinrock's UCLA webpage profile as "very misleading". [130] [131] Walter Isaacson wrote that Kleinrock's claims "led to an outcry among many of the other Internet pioneers, who publicly attacked Kleinrock and said that his brief mention of breaking messages into smaller pieces did not come close to being a proposal for packet switching". [129]

Davies' paper reignited a previous dispute over who deserves credit for getting the ARPANET online between engineers at Bolt, Beranek, and Newman (BBN) who had been involved in building and designing the ARPANET IMP on the one side, and ARPA-related researchers on the other. [78] [79] This earlier dispute is exemplified by BBN's Will Crowther, who in a 1990 oral history described Paul Baran's packet switching design (which he called hot-potato routing), as "crazy" and non-sensical, despite the ARPA team having advocated for it. [132] The reignited debate caused other former BBN employees to make their concerns known, including Alex McKenzie, who followed Davies in disputing that Kleinrock's work was related to packet switching, stating "... there is nothing in the entire 1964 book that suggests, analyzes, or alludes to the idea of packetization". [133]

Former IPTO director Bob Taylor also joined the debate, stating that "authors who have interviewed dozens of Arpanet pioneers know very well that the Kleinrock-Roberts claims are not believed". [134] Walter Isaacson notes that "until the mid-1990s Kleinrock had credited [Baran and Davies] with coming up with the idea of packet switching". [129]

A subsequent version of Kleinrock's biography webpage was copyrighted in 2009 by Kleinrock. [135] He was called on to defend his position over subsequent decades. [136] A paper published in the journal Internet Histories in 2019 supported Kleinrock's view; [137] the author interviewed Kleinrock and Roberts, and did not interview Scantlebury. [138] In 2023, Kleinrock acknowledged that his work published in the early 1960s was about message switching and claimed he was thinking about packet switching. [139] Primary sources and historians recognize Baran and Davies for independently inventing the concept of digital packet switching used in modern computer networking including the ARPANET and the Internet. [8] [9] [40] [140] [141]

Kleinrock has received many awards for his ground-breaking applied mathematical research on packet switching, carried out in the 1970s, which was an extension of his pioneering work in the early 1960s on the optimization of message delays in communication networks. [83] [142] However, Kleinrock's claims that his work in the early 1960s originated the concept of packet switching and that his work was a source of the packet switching concepts used in the ARPANET have affected sources on the topic, which has created methodological challenges in the historiography of the Internet. [124] [129] [131] [136] Historian Andrew L. Russell said "'Internet history' also suffers from a ... methodological, problem: it tends to be too close to its sources. Many Internet pioneers are alive, active, and eager to shape the histories that describe their accomplishments. Many museums and historians are equally eager to interview the pioneers and to publicize their stories". [143]

Connectionless and connection-oriented modes

Packet switching may be classified into connectionless packet switching, also known as datagram switching, and connection-oriented packet switching, also known as virtual circuit switching. Examples of connectionless systems are Ethernet, IP, and the User Datagram Protocol (UDP). Connection-oriented systems include X.25, Frame Relay, Multiprotocol Label Switching (MPLS), and TCP.

In connectionless mode each packet is labeled with a destination address, source address, and port numbers. It may also be labeled with the sequence number of the packet. This information eliminates the need for a pre-established path to help the packet find its way to its destination, but means that more information is needed in the packet header, which is therefore larger. The packets are routed individually, sometimes taking different paths resulting in out-of-order delivery. At the destination, the original message may be reassembled in the correct order, based on the packet sequence numbers. Thus a virtual circuit carrying a byte stream is provided to the application by a transport layer protocol, although the network only provides a connectionless network layer service.

Connection-oriented transmission requires a setup phase to establish the parameters of communication before any packet is transferred. The signaling protocols used for setup allow the application to specify its requirements and discover link parameters. Acceptable values for service parameters may be negotiated. The packets transferred may include a connection identifier rather than address information and the packet header can be smaller, as it only needs to contain this code and any information, such as length, timestamp, or sequence number, which is different for different packets. In this case, address information is only transferred to each node during the connection setup phase, when the route to the destination is discovered and an entry is added to the switching table in each network node through which the connection passes. When a connection identifier is used, routing a packet requires the node to look up the connection identifier in a table.[ citation needed ]

Connection-oriented transport layer protocols such as TCP provide a connection-oriented service by using an underlying connectionless network. In this case, the end-to-end principle dictates that the end nodes, not the network itself, are responsible for the connection-oriented behavior.

Packet switching in networks

In telecommunication networks, packet switching is used to optimize the usage of channel capacity and increase robustness. [61] Compared to circuit switching, packet switching is highly dynamic, allocating channel capacity based on usage instead of explicit reservations. This can reduce wasted capacity caused by underutilized reservations at the cost of removing bandwidth guarantees. In practice, congestion control is generally used in IP networks to dynamically negotiate capacity between connections. Packet switching may also increase the robustness of networks in the face of failures. If a node fails, connections do not need to be interrupted, as packets may be routed around the failure.

Packet switching is used in the Internet and most local area networks. The Internet is implemented by the Internet Protocol Suite using a variety of link layer technologies. For example, Ethernet and Frame Relay are common. Newer mobile phone technologies (e.g., GSM, LTE) also use packet switching. Packet switching is associated with connectionless networking because, in these systems, no connection agreement needs to be established between communicating parties prior to exchanging data.

X.25, the international CCITT standard of 1976, is a notable use of packet switching in that it provides to users a service of flow-controlled virtual circuits. These virtual circuits reliably carry variable-length packets with data order preservation. DATAPAC in Canada was the first public network to support X.25, followed by TRANSPAC in France. [144]

Asynchronous Transfer Mode (ATM) is another virtual circuit technology. It differs from X.25 in that it uses small fixed-length packets (cells), and that the network imposes no flow control to users.

Technologies such as MPLS and the Resource Reservation Protocol (RSVP) create virtual circuits on top of datagram networks. MPLS and its predecessors, as well as ATM, have been called "fast packet" technologies. MPLS, indeed, has been called "ATM without cells". [145] Virtual circuits are especially useful in building robust failover mechanisms and allocating bandwidth for delay-sensitive applications.

Packet-switched networks

This list of packet-switched networks is divided into three overlapping eras: early, isolated, networks before the introduction of X.25; the X.25 era when many postal, telephone, and telegraph (PTT) companies provided public data networks with worldwide reach; and the modern Internet era, which initially competed with the OSI model.

The work of Donald Davies in the late 1960s on data communication and computer network design became well known in the United States, Europe and Japan. This was the "cornerstone" that inspired numerous packet switching networks in the decade following. ( Full article... )

See also

References

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  28. 1 2 Davies, D. W. (1966). "Proposal for a Digital Communication Network" (PDF). all users of the network will provide themselves with some kind of error control ... Computer developments in the distant future might result in one type of network being able to carry speech and digital messages efficiently.
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  35. ↑ Moschovitis 1999 , p.  58-9 More significantly, Roger Scantlebury ... presents the design for a packet-switched network. This is the first Roberts and Taylor have heard of packet switching, a concept that appears to be a promising receipe for transmitting data through the ARPAnet.
  36. ↑ Hempstead, C.; Worthington, W., eds. (2005). Encyclopedia of 20th-Century Technology. Vol. 1, A–L. Routledge. p. 574. ISBN   9781135455514. It was a seminal meeting as the NPL proposal illustrated how the communications for such a resource-sharing computer network could be realized.
  37. ↑ "On packet switching". Net History. Retrieved 2024-01-08. [Scantlebury said] We referenced Baran's paper in our 1967 Gatlinburg ACM paper. You will find it in the References. Therefore I am sure that we introduced Baran's work to Larry (and hence the BBN guys).
  38. 1 2 Naughton, John (2015). A Brief History of the Future: The origins of the Internet. Hachette. ISBN   978-1474602778. they lacked one vital ingredient. Since none of them had heard of Paul Baran they had no serious idea of how to make the system work. And it took an English outfit to tell them. ... Larry Roberts paper was the first public presentation of the ARPANET concept as conceived with the aid of Wesley Clark ... Looking at it now, Roberts paper seems extraordinarily, well, vague.
  39. ↑ Waldrop, M. Mitchell (2018). The Dream Machine. Stripe Press. pp. 285–6. ISBN   978-1-953953-36-0. Scantlebury and his companions from the NPL group were happy to sit up with Roberts all that night, sharing technical details and arguing over the finer points.
  40. 1 2 3 Abbate, Jane (2000). Inventing the Internet. MIT Press. pp. 37–8, 58–9. ISBN   978-0262261333. 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 design.
  41. ↑ "Donald W. Davies and Derek L.A. Barber: An Interview Conducted by Janet Abbate, IEEE History Center". March 17, 1996. Retrieved 13 April 2016. the ARPA network is being implemented using existing telegraphic techniques simply because the type of network we describe does not exist. It appears that the ideas in the NPL paper at this moment are more advanced than any proposed in the USA
  42. ↑ Barber, Derek (Spring 1993). "The Origins of Packet Switching". The Bulletin of the Computer Conservation Society (5). ISSN   0958-7403 . Retrieved 6 September 2017. Roger actually convinced Larry that what he was talking about was all wrong and that the way that NPL were proposing to do it was right. I've got some notes that say that first Larry was sceptical but several of the others there sided with Roger and eventually Larry was overwhelmed by the numbers.
  43. ↑ Needham, Roger M. (2002-12-01). "Donald Watts Davies, C.B.E. 7 June 1924 – 28 May 2000" . Biographical Memoirs of Fellows of the Royal Society. 48: 87–96. doi:10.1098/rsbm.2002.0006. S2CID   72835589. Larry Roberts presented a paper on early ideas for what was to become ARPAnet. This was based on a store-and-forward method for entire messages, but as a result of that meeting the NPL work helped to convince Roberts that packet switching was the way forward.
  44. ↑ Rayner, David; Barber, Derek; Scantlebury, Roger; Wilkinson, Peter (2001). NPL, Packet Switching and the Internet. Symposium of the Institution of Analysts & Programmers 2001. Archived from the original on 2003-08-07. Retrieved 2024-06-13. The system first went 'live' early in 1969
  45. ↑ John S, Quarterman; Josiah C, Hoskins (1986). "Notable computer networks". Communications of the ACM. 29 (10): 932–971. doi: 10.1145/6617.6618 . S2CID   25341056. 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.
  46. ↑ Haughney Dare-Bryan, Christine (June 22, 2023). Computer Freaks (Podcast). Chapter Two: In the Air. Inc. Magazine. 35:55 minutes in. Leonard Kleinrock: Donald Davies ... did make a single node packet switch before ARPA did
  47. 1 2 C. Hempstead; W. Worthington (2005). Encyclopedia of 20th-Century Technology. Routledge. pp. 573–5. ISBN   9781135455514.
  48. ↑ Campbell-Kelly, Martin (1987). "Data Communications at the National Physical Laboratory (1965-1975)". Annals of the History of Computing. 9 (3/4): 221–247. Bibcode:1987IAHC....9c.221C. doi:10.1109/MAHC.1987.10023. S2CID   8172150.
  49. ↑ Needham, R. M. (2002). "Donald Watts Davies, C.B.E. 7 June 1924 – 28 May 2000". Biographical Memoirs of Fellows of the Royal Society . 48: 87–96. doi:10.1098/rsbm.2002.0006. S2CID   72835589. The 1967 Gatlinburg paper was influential on the development of ARPAnet, which might otherwise have been built with less extensible technology. ... Davies was invited to Japan to lecture on packet switching.
  50. ↑ Clarke, Peter (1982). Packet and circuit-switched data networks (PDF) (PhD thesis). Department of Electrical Engineering, Imperial College of Science and Technology, University of London. Archived from the original (PDF) on 2022-08-03. Retrieved 2024-01-21. "As well as the packet switched network actually built at NPL for communication between their local computing facilities, some simulation experiments have been performed on larger networks. A summary of this work is reported in [69]. The work was carried out to investigate networks of a size capable of providing data communications facilities to most of the U.K. ... Experiments were then carried out using a method of flow control devised by Davies [70] called 'isarithmic' flow control. ... The simulation work carried out at NPL has, in many respects, been more realistic than most of the ARPA network theoretical studies."
  51. ↑ Pelkey, James. "6.3 CYCLADES Network and Louis Pouzin 1971-1972". Entrepreneurial Capitalism and Innovation: A History of Computer Communications 1968-1988. Archived from the original on 2021-06-17. Retrieved 2020-02-03.
  52. ↑ Campbell-Kelly, Martin (Autumn 2008). "Pioneer Profiles: Donald Davies". Computer Resurrection (44). ISSN   0958-7403.
  53. ↑ Wilkinson, Peter (2001). NPL Development of Packet Switching. Symposium of the Institution of Analysts & Programmers 2001. Archived from the original on 2003-08-07. Retrieved 2024-06-13. The feasibility studies continued with an attempt to apply queuing theory to study overall network performance. This proved to be intractable so we quickly turned to simulation.
  54. 1 2 Hafner, Katie (2018-12-30). "Lawrence Roberts, Who Helped Design Internet's Precursor, Dies at 81". The New York Times. ISSN   0362-4331 . Retrieved 2020-02-20. 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 of today's internet.
  55. ↑ Waldrop, M. Mitchell (2018). The Dream Machine. Stripe Press. pp. 285–6. ISBN   978-1-953953-36-0. Oops. Roberts knew Baran slightly and had in fact had lunch with him during a visit to RAND the previous February. But he certainly didn't remember any discussion of networks. How could he have missed something like that?
  56. ↑ O'Neill, Judy (5 March 1990). "An Interview with PAUL BARAN" (PDF). p. 37. On Tuesday, 28 February 1967 I find a notation on my calendar for 12:00 noon Dr. L. Roberts.
  57. ↑ Pelkey, James. "4.7 Planning the ARPANET: 1967-1968 in Chapter 4 - Networking: Vision and Packet Switching 1959 - 1968". The History of Computer Communications. Archived from the original on December 23, 2022. Retrieved May 9, 2023.
  58. ↑ Press, Gil (January 2, 2015). "A Very Short History Of The Internet And The Web". Forbes. Archived from the original on January 9, 2015. Retrieved 2020-02-07. Roberts' proposal that all host computers would connect to one another directly ... was not endorsed ... Wesley Clark ... suggested to Roberts that the network be managed by identical small computers, each attached to a host computer. Accepting the idea, Roberts named the small computers dedicated to network administration 'Interface Message Processors' (IMPs), which later evolved into today's routers.
  59. ↑ SRI Project 5890-1; Networking (Reports on Meetings), Stanford University, 1967, archived from the original on February 2, 2020, retrieved 2020-02-15, W. Clark's message switching proposal (appended to Taylor's letter of April 24, 1967 to Engelbart)were reviewed.
  60. 1 2 Roberts, Lawrence (1967). "Multiple computer networks and intercomputer communication" (PDF). Multiple Computer Networks and Intercomputer Communications. pp. 3.1 –3.6. doi:10.1145/800001.811680. S2CID   17409102. Thus the set of IMP's, plus the telephone lines and data sets would constitute a message switching network
  61. 1 2 3 Tanenbaum, Andrew S.; Wetherall, David (2011). Computer networks (PDF) (5th ed.). Boston Amsterdam: Prentice Hall. p. 57. ISBN   978-0-13-212695-3. Roberts bought the idea and presented a some what vague paper about it at the ACM SIGOPS Symposium on Operating System Principles held in Gatlinburg, Tennessee in late 1967
  62. ↑ Waldrop, M. Mitchell (2018). The Dream Machine. Stripe Press. pp. 279, 284–5. ISBN   978-1-953953-36-0. Roberts was already becoming known as the fastest man in the Pentagon. ... And not for nothing was Larry Roberts known as the fastest man in the Pentagon. By the time they got to the airport, the decision had been made .... Once again, the fastest man in the Pentagon made his decision without hesitation
  63. 1 2 "Shapiro: Computer Network Meeting of October 9–10, 1967". stanford.edu. Archived from the original on 27 June 2015.
  64. ↑ "Computer Pioneers - Donald W. Davies". IEEE Computer Society. Retrieved 2020-02-20. In 1965, Davies pioneered new concepts for computer communications in a form to which he gave the name "packet switching." ... The design of the ARPA network (ArpaNet) was entirely changed to adopt this technique.
  65. ↑ "Pioneer: Donald Davies", Internet Hall of Fame "America’s Advanced Research Project Agency (ARPA), and the ARPANET received his network design enthusiastically and the NPL local network became the first two computer networks in the world using the technique."
  66. ↑ Abbate, Janet (2000). Inventing the Internet. Cambridge, MA: MIT Press. pp. 39, 57–58. ISBN   978-0-2625-1115-5. Baran proposed a "distributed adaptive message-block network" [in the early 1960s] ... Roberts recruited Baran to advise the ARPANET planning group on distributed communications and packet switching.
  67. ↑ Isaacson, Walter (2014). The Innovators: How a Group of Hackers, Geniuses, and Geeks Created the Digital Revolution. Simon and Schuster. p. 246. ISBN   9781476708690.
  68. ↑ Davies, D. W. (1966). "Proposal for a Digital Communication Network" (PDF). p. 10, 16.
  69. ↑ Heart, F.; McKenzie, A.; McQuillian, J.; Walden, D. (January 4, 1978). Arpanet Completion Report (PDF) (Technical report). Burlington, MA: Bolt, Beranek and Newman. pp. III-40-1
  70. ↑ "SRI Project 5890-1; Networking (Reports on Meetings). [1967]". web.stanford.edu. Archived from the original on 2011-08-10. Retrieved 2020-02-15.
  71. ↑ Hafner & Lyon 1996
  72. 1 2 Abbate, Janet (2000). Inventing the Internet. Cambridge, MA: MIT Press. pp. 39, 57–58. ISBN   978-0-2625-1115-5. Baran proposed a "distributed adaptive message-block network" [in the early 1960s] ... Roberts recruited Baran to advise the ARPANET planning group on distributed communications and packet switching. ... Roberts awarded a contract to Leonard Kleinrock of UCLA to create theoretical models of the network and to analyze its actual performance.
  73. ↑ Summary of ARPA ad hoc meeting, November 3, 1967, We propose that a working group of approximately four people devote some concentrated effort in the near future in defining the IMP precisely. This group would interact with the larger group from the earlier meetings from time to time. Tentatively we think that the core of this investigatory group would be Bhushan (MIT), Kleinrock (UCLA), Shapiro (SRI) and Westervelt (University of Michigan), along with a kibitzer's group, consisting of such people as Baran (Rand), Boehm (Rand), Culler (UCSB) and Roberts (ARPA).
  74. ↑ Judy O'Neill (1990), Oral history interview with Paul Baran, Charles Babbage Institute, hdl:11299/107101, BARAN: On Tuesday, 31 October 1967 I see a notation 9:30 AM to 2:00 PM for ARPA's (Elmer) Shapiro, (Barry) Boehm, (Len) Kleinrock, ARPA Network. On Monday, 13 November 1967 I see the following: Larry Roberts to abt (about?) lunch (time?). Art Bushkin = 1:00 PM. Here. Larry Roberts IMP Committee. On Thursday, 16 November 1967 I see 7 PM Kleinrock, UCLA - IMP Meeting.
  75. ↑ Meeting of the ARPA Computer Network Working Group at UCLA, November 16, 1967
  76. 1 2 Hafner & Lyon 1996 , pp.  116, 149
  77. ↑ Pelkey, James L. "6.1 The Communications Subnet: BBN 1969". Entrepreneurial Capitalism and Innovation: A History of Computer Communications 1968–1988. Kahn, the principal architect
  78. 1 2 Roberts, Lawrence G. (November 1978). "The Evolution of Packet Switching" (PDF). IEEE Invited Paper. 66 (11): 1307. Bibcode:1978IEEEP..66.1307R. doi:10.1109/PROC.1978.11141. Archived from the original (PDF) on 31 December 2018. Retrieved September 10, 2017. Significant aspects of the network's internal operation, such as routing, flow control, software design, and network control were developed by a BBN team consisting of Frank Heart, Robert Kahn, Severo Omstein, William Crowther, and David Walden
  79. 1 2 F.E. Froehlich, A. Kent (1990). The Froehlich/Kent Encyclopedia of Telecommunications: Volume 1 - Access Charges in the U.S.A. to Basics of Digital Communications. CRC Press. p. 344. ISBN   0824729005. Although there was considerable technical interchange between the NPL group and those who designed and implemented the ARPANET, the NPL Data Network effort appears to have had little fundamental impact on the design of ARPANET. Such major aspects of the NPL Data Network design as the standard network interface, the routing algorithm, and the software structure of the switching node were largely ignored by the ARPANET designers. There is no doubt, however, that in many less fundamental ways the NPL Data Network had and effect on the design and evolution of the ARPANET.
  80. ↑ RFC   334
  81. ↑ RFC   53
  82. ↑ Heart, F.; McKenzie, A.; McQuillian, J.; Walden, D. (January 4, 1978). Arpanet Completion Report (PDF) (Technical report). Burlington, MA: Bolt, Beranek and Newman. p. III-63.
  83. 1 2 3 Clarke, Peter (1982). Packet and circuit-switched data networks (PDF) (PhD thesis). Department of Electrical Engineering, Imperial College of Science and Technology, University of London. Archived from the original (PDF) on 2022-08-03. Retrieved 2024-01-21. "Many of the theoretical studies of the performance and design of the ARPA Network were developments of earlier work by Kleinrock ... Although these works concerned message switching networks, they were the basis for a lot of the ARPA network investigations ... The intention of the work of Kleinrock [in 1961] was to analyse the performance of store and forward networks ... Kleinrock [in 1970] extended the theoretical approaches of [his 1961 work] to the early ARPA network."
  84. ↑ Pelkey, James. "8.3 CYCLADES Network and Louis Pouzin 1971–1972". Entrepreneurial Capitalism and Innovation: A History of Computer Communications 1968–1988.
  85. ↑ Hafner & Lyon 1996 , p.  222
  86. ↑ Pelkey, James. "8.4 Transmission Control Protocol (TCP) 1973-1976". Entrepreneurial Capitalism and Innovation: A History of Computer Communications 1968–1988. Arpanet had its deficiencies, however, for it was neither a true datagram network nor did it provide end-to-end error correction.
  87. ↑ 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. S2CID   1689917.
  88. ↑ Roberts, Dr. Lawrence G. (November 1978). "The Evolution of Packet Switching" (PDF). IEEE Invited Paper. 66 (11): 1307. Bibcode:1978IEEEP..66.1307R. doi:10.1109/PROC.1978.11141. Archived from the original (PDF) on December 31, 2018. Retrieved September 10, 2017.
  89. ↑ Bochmann, Gregor v.; Rayner, Dave; West, Colin H. (2010-12-20). "Some notes on the history of protocol engineering" . Computer Networks. 54 (18): 3197–3209. doi:10.1016/j.comnet.2010.05.019. ISSN   1389-1286.
  90. ↑ Abbate, Janet (2000). Inventing the Internet. MIT Press. pp. 124–127. ISBN   978-0-262-51115-5. In fact, CYCLADES, unlike ARPANET, had been explicitly designed to facilitate internetworking; it could, for instance, handle varying formats and varying levels of service
  91. ↑ Kim, Byung-Keun (2005). Internationalising the Internet the Co-evolution of Influence and Technology. Edward Elgar. pp. 51–55. ISBN   1845426754. In addition to the NPL Network and the ARPANET, CYCLADES, an academic and research experimental network, also played an important role in the development of computer networking technologies
  92. ↑ "The internet's fifth man". The Economist. 2013-11-30. ISSN   0013-0613 . Retrieved 2020-04-22. 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.
  93. ↑ 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, 9, 11. Retrieved 11 September 2017. Two significant packet networks preceded the TCP/IP Internet: ARPANET and CYCLADES. The designers of the Internet borrowed heavily from these systems, especially CYCLADES ... The first end-to-end research network was CYCLADES, designed by Louis Pouzin at IRIA in France with the support of BBN's Dave Walden and Alex McKenzie and deployed beginning in 1972.
  94. ↑ Green, Lelia (2010). The internet: an introduction to new media. Berg new media series. Berg. p. 31. ISBN   978-1-84788-299-8. OCLC   504280762. 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.
  95. ↑ Moschovitis 1999 , p.  78-9
  96. ↑ Cerf, V.; Kahn, R. (1974). "A Protocol for Packet Network Intercommunication" (PDF). IEEE Transactions on Communications. 22 (5): 637–648. Bibcode:1974ITCom..22..637C. doi:10.1109/TCOM.1974.1092259. ISSN   1558-0857. Archived (PDF) from the original on 2022-10-10. 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.
  97. ↑ Cerf, Vinton; Dalal, Yogen; Sunshine, Carl (December 1974). Specification of Internet Transmission Control Protocol. IETF. doi: 10.17487/RFC0675 . RFC 675.
  98. ↑ Postel, Jon (August 29, 1979). "Comparison of X.25 and TCP Version 4 as Cable-bus Network Protocols" (PDF).
  99. ↑ Cerf, Vinton G.; Postel, Jon (August 18, 1977). "Specification of Internetwork Transmission Program: TCP Version 3" (PDF). p. iii, 75-87.
  100. ↑ Postel, Jon (September 1978). "Specification of Internetwork Transmission Control Protocol: TCP Version 4" (PDF). pp. iii, 85–97.
  101. ↑ Cerf, Vinton G. (1 April 1980). "Final Report of the Stanford University TCP Project".
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  103. ↑ "ISI Names Dr. Paul Mockapetris Visiting Scholar" Archived 2012-08-26 at the Wayback Machine , Information Sciences Institute, University of Southern California, 27 March 2003
  104. ↑ "Congestion avoidance and control", Van Jacobson, ACM SIGCOMM Computer Communication Review - Special twenty-fifth anniversary issue, Highlights from 25 years of the Computer Communication Review, Volume 25 Issue 1, Jan. 1995, pp.157-187
  105. ↑ Postel, J. (7 February 1979). "Internet Meeting Notes -- 25 & 26 January 1979" (PDF). p. 5. Retrieved 9 February 2022. Vint noted that UCLA's internet work is primarily theoretical research on throughput and delay analysis. This work is headed by L. Kleinrock.
  106. ↑ Davies, Donald Watts (1979). Computer networks and their protocols. Internet Archive. Wiley. pp. See page refs highlighted at url. ISBN   978-0-471-99750-4. In mathematical modelling use is made of the theories of queueing processes and of flows in networks, describing the performance of the network in a set of equations. ... The analytic method has been used with success by Kleinrock and others, but only if important simplifying assumptions are made. ... It is heartening in Kleinrock's work to see the good correspondence achieved between the results of analytic methods and those of simulation.
  107. ↑ Davies, Donald Watts (1979). Computer networks and their protocols. Internet Archive. Wiley. pp. 110–111. ISBN   978-0-471-99750-4. Hierarchical addressing systems for network routing have been proposed by Fultz and, in greater detail, by McQuillan. A recent very full analysis may be found in Kleinrock and Kamoun.
  108. ↑ Feldmann, Anja; Cittadini, Luca; Mühlbauer, Wolfgang; Bush, Randy; Maennel, Olaf (2009). "HAIR: Hierarchical architecture for internet routing" (PDF). Proceedings of the 2009 workshop on Re-architecting the internet. ReArch '09. New York, NY, USA: Association for Computing Machinery. pp. 43–48. doi:10.1145/1658978.1658990. ISBN   978-1-60558-749-3. S2CID   2930578. The hierarchical approach is further motivated by theoretical results (e.g., [16]) which show that, by optimally placing separators, i.e., elements that connect levels in the hierarchy, tremendous gain can be achieved in terms of both routing table size and update message churn. ... [16] KLEINROCK, L., AND KAMOUN, F. Hierarchical routing for large networks: Performance evaluation and optimization. Computer Networks (1977).
  109. ↑ "Leonard Kleinrock". Internet Hall of Fame. Retrieved 2023-03-13.
  110. ↑ "Kleinrock (Leonard) papers". oac.cdlib.org. Retrieved 2023-04-04.
  111. ↑ Abbate, Janet (1999). Inventing the Internet. Internet Archive. MIT Press. pp. 81, 230. ISBN   978-0-262-01172-3. Leonard Kleinrock's work became the basic reference in queuing theory for computer networks ... On Kleinrock's influence, see Frank, Kahn, and Kleinrock 1972, p. 265; Tanenbaum 1989, p. 631.
  112. ↑ Davies, Donald Watts (1979). Computer networks and their protocols. Internet Archive. Wiley. pp. See page refs highlighted at url. ISBN   978-0-471-99750-4.
  113. ↑ Camrass, R.; Gallager, R. (1978). "Encoding message lengths for data transmission (Corresp.)". IEEE Transactions on Information Theory. 24 (4): 495–496. Bibcode:1978ITIT...24..495C. doi:10.1109/TIT.1978.1055910. ISSN   0018-9448.
  114. ↑ "Reflections on an Internet pioneer: Roger Camrass". stories.clare.cam.ac.uk. Retrieved 2024-07-01.
  115. ↑ Andrew L. Russell (30 July 2013). "OSI: The Internet That Wasn't". IEEE Spectrum . Vol. 50, no. 8.
  116. ↑ Russell, Andrew L. "Rough Consensus and Running Code' and the Internet-OSI Standards War" (PDF). IEEE Annals of the History of Computing. Archived (PDF) from the original on 2019-11-17.
  117. ↑ Davies, Howard; Bressan, Beatrice (2010). "The Protocol Wars". A History of International Research Networking: The People who Made it Happen. John Wiley & Sons. pp. 106–110. ISBN   978-3-527-32710-2.
  118. ↑ Hayward, G.; Gottlieb, A.; Jain, S.; Mahoney, D. (October 1987). "CMOS VLSI Applications in Broadband Circuit Switching". IEEE Journal on Selected Areas in Communications. 5 (8): 1231–1241. Bibcode:1987IJSAC...5.1231H. doi:10.1109/JSAC.1987.1146652. ISSN   1558-0008.
  119. ↑ Hui, J.; Arthurs, E. (October 1987). "A Broadband Packet Switch for Integrated Transport". IEEE Journal on Selected Areas in Communications. 5 (8): 1264–1273. Bibcode:1987IJSAC...5.1264H. doi:10.1109/JSAC.1987.1146650. ISSN   1558-0008.
  120. ↑ Gibson, Jerry D. (2018). The Communications Handbook. CRC Press. ISBN   9781420041163.
  121. ↑ Kirstein, Peter T. (2009). "The early history of packet switching in the UK". IEEE Communications Magazine. 47 (2): 18–26. doi:10.1109/MCOM.2009.4785372. S2CID   34735326. It is more difficult to establish at this time, however, whether Larry intended to switch the fragments as independent packets in the ARPAnet before he heard of the NPL work; certainly he now claims that this was always his intention.
  122. ↑ technicshistory (2019-06-02). "ARPANET, Part 2: The Packet". Creatures of Thought. Retrieved 2024-06-21. The above description of how packet-switching came to be is the most widely-accepted one. However, there is an alternative version. Roberts claimed in later years that by the time of the Gatlinburg symposium, he already had the basic concepts of packet-switching well in mind, and that they originated with his old colleague Len Kleinrock, who had written about them as early as 1962, as part of his Ph.D. research on communication nets. It requires a great deal of squinting to extract anything resembling packet-switching from Kleinrock's work, however, and no other contemporary textual evidence that I have come across backs the Kleinrock/Roberts account.
  123. ↑ Barry M. Leiner, Vinton G. Cerf, David D. Clark, Robert E. Kahn, Leonard Kleinrock, Daniel C. Lynch, Jon Postel, Larry G. Roberts, Stephen Wolff (1997), Brief History of the Internet, Internet Society{{citation}}: CS1 maint: multiple names: authors list (link)
  124. 1 2 Katie Hafner (November 8, 2001), "A Paternity Dispute Divides Net Pioneers", New York Times, The Internet is really the work of a thousand people," Mr. Baran said. "And of all the stories about what different people have done, all the pieces fit together. It's just this one little case that seems to be an aberration.
  125. ↑ Kahn, R.E.; Uncapher, K.W.; van Trees, H.L. (1978). "Scanning the issue". Proceedings of the IEEE. 66 (11): 1303–1306. doi:10.1109/PROC.1978.11140. ISSN   0018-9219.
  126. ↑ Roberts, Lawrence G. (1982). "Packet Switching Economics". Ericsson Review. 89 (3): 128.
  127. ↑ Kleinrock, Leonard (1982). "Packet Switching Principles". Ericsson Review. 89 (3): 121–4.
  128. ↑ UCLA Computer Science Dept. "Leonard Kleinrock, Professor (archived)". UCLA Computer Science Dept. Archived from the original on Feb 27, 2004. Retrieved 28 December 2023.
  129. 1 2 3 4 Isaacson, Walter (2014). The Innovators: How a Group of Hackers, Geniuses, and Geeks Created the Digital Revolution. Simon & Schuster. pp. 244–6. ISBN   9781476708690.
  130. ↑ Donald W. Davies (2001), "An Historical Study of the Beginnings of Packet Switching" , The Computer Journal, 44 (3): 152–162, doi:10.1093/comjnl/44.3.152, I can find no evidence that he understood the principles of packet switching.
  131. 1 2 Harris, Trevor, University of Wales (2009). Pasadeos, Yorgo (ed.). "Who is the Father of the Internet? The Case for Donald Davies". Variety in Mass Communication Research. ATINER: 123–134. ISBN   978-960-6672-46-0. Archived from the original on May 2, 2022. Leonard Kleinrock and Lawrence (Larry) Roberts, neither of whom were directly involved in the invention of packet switching ... Dr Willis H. Ware, Senior Computer Scientist and Research at the RAND Corporation, notes that Davies (and others) were troubled by what they regarded as in appropriate claims on the invention of packet switching{{cite journal}}: CS1 maint: multiple names: authors list (link)
  132. ↑ Judy O'Neill (12 March 1990), Oral history interview with William Crowther, hdl:11299/107235, ...there were all sorts of crazy ideas about, and most of them didn't make any sense. There was this 'hot potato' routing which somebody was advocating, which was just crazy.
  133. ↑ Alex McKenzie (2009), Comments on Dr. Leonard Kleinrock's claim to be "the Father of Modern Data Networking" , retrieved April 23, 2015
  134. ↑ Robert Taylor (November 22, 2001), "Birthing the Internet: Letters From the Delivery Room; Disputing a Claim", New York Times
  135. ↑ Leonard Kleinrock, Leonard Kleinrock - UCLA Dept. of Computer Science, archived from the original on December 5, 2023, He developed the mathematical theory of data networks, the technology underpinning the Internet, while a graduate student at MIT in the period from 1960-1962. In that work, he also modeled the packetization of messages and solved for a key performance gain that packetization provides.
  136. 1 2 Schwartz, Mischa; Adamson, Greg; Kleinrock, Leonard (February 2011), "Letters to the editor", IEEE Communications, 49 (2): 12, Bibcode:2011IComM..49b..12S, doi:10.1109/MCOM.2011.5706298
  137. ↑ Bay, Morten (2019). "Hot potatoes and postmen: how packet switching became ARPANET's greatest legacy". Internet Histories. 3 (1): 15–30. doi:10.1080/24701475.2018.1544726. ISSN   2470-1475.
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  141. ↑ A History of the ARPANET: The First Decade (PDF) (Report). Bolt, Beranek & Newman Inc. 1 April 1981. pp. 13, 53 of 183. Archived from the original on 1 December 2012. Aside from the technical problems of interconnecting computers with communications circuits, the notion of computer networks had been considered in a number of places from a theoretical point of view. Of particular note was work done by Paul Baran and others at the Rand Corporation in a study "On Distributed Communications" in the early 1960's. Also of note was work done by Donald Davies and others at the National Physical Laboratory in England in the mid-1960's. ... Another early major network development which affected development of the ARPANET was undertaken at the National Physical Laboratory in Middlesex, England, under the leadership of D. W. Davies.
  142. ↑ "Leonard Kleinrock". UCLA Samueli School Of Engineering. Retrieved 2024-01-20.
  143. ↑ Russell, Andrew (2012). Histories of Networking vs. the History of the Internet (PDF). 2012 SIGCIS Workshop. p. 6.
  144. ↑ Schwartz, Mischa; Després, Rémi (2010), "X.25 Virtual Circuits - TRANSPAC in France - Pre-Internet Data Networking", IEEE Communications Magazine, 48 (11): 40, Bibcode:2010IComM..48k..40S, doi:10.1109/MCOM.2010.5621965, S2CID   23639680
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