Local area network

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A conceptual diagram of a local area network using bus network topology Ethernet LAN.svg
A conceptual diagram of a local area network using bus network topology

A local area network (LAN) is a computer network that interconnects computers within a limited area such as a residence, school, laboratory, university campus or office building. [1] By contrast, a wide area network (WAN) not only covers a larger geographic distance, but also generally involves leased telecommunication circuits.

Contents

Ethernet and Wi-Fi are the two most common technologies in use for local area networks. Historical network technologies include ARCNET, Token Ring and AppleTalk.

History

The increasing demand and usage of computers in universities and research labs in the late 1960s generated the need to provide high-speed interconnections between computer systems. A 1970 report from the Lawrence Radiation Laboratory detailing the growth of their "Octopus" network gave a good indication of the situation. [2] [3]

A number of experimental and early commercial LAN technologies were developed in the 1970s. Ethernet was developed at Xerox PARC between 1973 and 1974. [4] [5] Cambridge Ring was developed at Cambridge University starting in 1974. [6] ARCNET was developed by Datapoint Corporation in 1976 and announced in 1977. [7] It had the first commercial installation in December 1977 at Chase Manhattan Bank in New York. [8] In 1979, [9] the Electronic voting systems for the European Parliament was the first installation of a LAN connecting hundreds (420) of microprocessor-controlled voting terminals to a polling/selecting central unit with a multidrop bus with Master/slave (technology) arbitration.[ dubious – discuss ]

The development and proliferation of personal computers using the CP/M operating system in the late 1970s, and later DOS-based systems starting in 1981, meant that many sites grew to dozens or even hundreds of computers. The initial driving force for networking was to share storage and printers, both of which were expensive at the time. There was much enthusiasm for the concept, and for several years, from about 1983 onward, computer industry pundits habitually declared the coming year to be, "The year of the LAN". [10] [11] [12]

In practice, the concept was marred by the proliferation of incompatible physical layer and network protocol implementations, and a plethora of methods of sharing resources. Typically, each vendor would have its own type of network card, cabling, protocol, and network operating system. A solution appeared with the advent of Novell NetWare which provided even-handed support for dozens of competing card and cable types, and a much more sophisticated operating system than most of its competitors.

Of the competitors to NetWare, only Banyan Vines had comparable technical strengths, but Banyan never gained a secure base. 3Com produced 3+Share and Microsoft produced MS-Net. These then formed the basis for collaboration between Microsoft and 3Com to create a simple network operating system LAN Manager and its cousin, IBM's LAN Server. None of these enjoyed any lasting success; Netware dominated the personal computer LAN business from early after its introduction in 1983 until the mid-1990s when Microsoft introduced Windows NT. [13]

In 1983, TCP/IP was first shown capable of supporting actual defense department applications on a Defense Communication Agency LAN testbed located at Reston, Virginia. [14] [15] The TCP/IP-based LAN successfully supported Telnet, FTP, and a Defense Department teleconferencing application. [16] This demonstrated the feasibility of employing TCP/IP LANs to interconnect Worldwide Military Command and Control System (WWMCCS) computers at command centers throughout the United States. [17] However, WWMCCS was superseded by the Global Command and Control System (GCCS) before that could happen.

During the same period, Unix workstations were using TCP/IP networking. Although the workstation market segment is now much reduced, the technologies developed in the area continue to be influential on the Internet and in all forms of networking—and the TCP/IP protocol has replaced IPX, AppleTalk, NBF, and other protocols used by the early PC LANs.

Econet was Acorn Computers's low-cost local area network system, intended for use by schools and small businesses. It was first developed for the Acorn Atom and Acorn System 2/3/4 computers in 1981. [18] [19]

In the 1980s, several token ring network implementations for LANs were developed. [20] [21] IBM released their own implementation of token ring in 1985, [22] [23] It ran at 4  Mbit/s . [24] IBM claimed that their token ring systems were superior to Ethernet, especially under load, but these claims were debated. [25] [26] IBM's implementation of token ring was the basis of the IEEE 802.5 standard. [27] A 16 Mbit/s version of Token Ring was standardized by the 802.5 working group in 1989. [28] IBM had market dominance over Token Ring, for example, in 1990, IBM equipment was the most widely used for Token Ring networks. [29]

Fiber Distributed Data Interface (FDDI), a LAN standard, was considered an attractive campus backbone network technology in the early to mid 1990s since existing Ethernet networks only offered 10 Mbit/s data rates and Token Ring networks only offered 4 Mbit/s or 16 Mbit/s rates. Thus it was a relatively high-speed choice of that era, with speeds such as 100 Mbit/s. By 1994, vendors included Cisco Systems, National Semiconductor, Network Peripherals, SysKonnect (acquired by Marvell Technology Group), and 3Com. [30] FDDI installations have largely been replaced by Ethernet deployments. [31]

Cabling

Twisted pair LAN cable RJ-45-Stecker-und-Buechse.jpg
Twisted pair LAN cable

In 1979, [9] the Electronic voting systems for the European Parliament was using 10 kilometers of simple unshielded twisted pair category 3 cable—the same cable used for telephone systems—installed inside the benches of the European Parliament Hemicycles in Strasbourg and Luxembourg. [32]

Early Ethernet (10BASE-5 and 10BASE-2) used coaxial cable. Shielded twisted pair was used in IBM's Token Ring LAN implementation. In 1984, StarLAN showed the potential of simple unshielded twisted pair by using category 3 cable—the same cable used for telephone systems. This led to the development of 10BASE-T (and its twisted-pair successors) and structured cabling which is still the basis of most commercial LANs today.

While optical fiber cable is common for links between network switches, use of fiber to the desktop is rare. [33]

Wireless media

In a wireless LAN, users have unrestricted movement within the coverage area. Wireless networks have become popular in residences and small businesses, because of their ease of installation. Most wireless LANs use Wi-Fi as wireless adapters are typically integrated into smartphones, tablet computers and laptops. Guests are often offered Internet access via a hotspot service.

Technical aspects

Network topology describes the layout of interconnections between devices and network segments. At the data link layer and physical layer, a wide variety of LAN topologies have been used, including ring, bus, mesh and star.

Simple LANs generally consist of cabling and one or more switches. A switch can be connected to a router, cable modem, or ADSL modem for Internet access. A LAN can include a wide variety of other network devices such as firewalls, load balancers, and network intrusion detection. [34] Advanced LANs are characterized by their use of redundant links with switches using the spanning tree protocol to prevent loops, their ability to manage differing traffic types via quality of service (QoS), and their ability to segregate traffic with VLANs.

At the higher network layers, protocols such as NetBIOS, IPX/SPX, AppleTalk and others were once common, but the Internet protocol suite (TCP/IP) has prevailed as the standard of choice.

LANs can maintain connections with other LANs via leased lines, leased services, or across the Internet using virtual private network technologies. Depending on how the connections are established and secured, and the distance involved, such linked LANs may also be classified as a metropolitan area network (MAN) or a wide area network (WAN).

See also

Related Research Articles

AppleTalk is a discontinued proprietary suite of networking protocols developed by Apple Computer for their Macintosh computers. AppleTalk includes a number of features that allow local area networks to be connected with no prior setup or the need for a centralized router or server of any sort. Connected AppleTalk-equipped systems automatically assign addresses, update the distributed namespace, and configure any required inter-networking routing.

<span class="mw-page-title-main">Ethernet</span> Computer networking technology

Ethernet is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 1983 as IEEE 802.3. Ethernet has since been refined to support higher bit rates, a greater number of nodes, and longer link distances, but retains much backward compatibility. Over time, Ethernet has largely replaced competing wired LAN technologies such as Token Ring, FDDI and ARCNET.

<span class="mw-page-title-main">Wake-on-LAN</span> Mechanism to wake up computers via a network

Wake-on-LAN is an Ethernet or Token Ring computer networking standard that allows a computer to be turned on or awakened from sleep mode by a network message.

100BaseVG is a 100 Mbit/s Ethernet standard specified to run over four pairs of Category 3 cable. It is also called 100VG-AnyLAN because it was defined to carry both Ethernet and Token Ring frame types.

<span class="mw-page-title-main">3Com</span> Former American maker of computer network products

3Com Corporation was an American digital electronics manufacturer best known for its computer network products. The company was co-founded in 1979 by Robert Metcalfe, Howard Charney and others. Bill Krause joined as President in 1981. Metcalfe explained the name 3Com was a contraction of "Computer Communication Compatibility", with its focus on Ethernet technology that he had co-invented, which enabled the networking of computers.

<span class="mw-page-title-main">Fiber Distributed Data Interface</span> Standard for data transmission in a local area network

Fiber Distributed Data Interface (FDDI) is a standard for data transmission in a local area network. It uses optical fiber as its standard underlying physical medium, although it was also later specified to use copper cable, in which case it may be called CDDI, standardized as TP-PMD, also referred to as TP-DDI.

<span class="mw-page-title-main">Metropolitan area network</span> Computer network serving a populated area

A metropolitan area network (MAN) is a computer network that interconnects users with computer resources in a geographic region of the size of a metropolitan area. The term MAN is applied to the interconnection of local area networks (LANs) in a city into a single larger network which may then also offer efficient connection to a wide area network. The term is also used to describe the interconnection of several LANs in a metropolitan area through the use of point-to-point connections between them.

<span class="mw-page-title-main">Fast Ethernet</span> Ethernet standards that carry data at the nominal rate of 100 Mbit/s

In computer networking, Fast Ethernet physical layers carry traffic at the nominal rate of 100 Mbit/s. The prior Ethernet speed was 10 Mbit/s. Of the Fast Ethernet physical layers, 100BASE-TX is by far the most common.

<span class="mw-page-title-main">ARCNET</span>

Attached Resource Computer NETwork is a communications protocol for local area networks. ARCNET was the first widely available networking system for microcomputers; it became popular in the 1980s for office automation tasks. It was later applied to embedded systems where certain features of the protocol are especially useful.

The data link layer, or layer 2, is the second layer of the seven-layer OSI model of computer networking. This layer is the protocol layer that transfers data between nodes on a network segment across the physical layer. The data link layer provides the functional and procedural means to transfer data between network entities and may also provide the means to detect and possibly correct errors that can occur in the physical layer.

NetBIOS is an acronym for Network Basic Input/Output System. It provides services related to the session layer of the OSI model allowing applications on separate computers to communicate over a local area network. As strictly an API, NetBIOS is not a networking protocol. Operating systems of the 1980s ran NetBIOS over IEEE 802.2 and IPX/SPX using the NetBIOS Frames (NBF) and NetBIOS over IPX/SPX (NBX) protocols, respectively. In modern networks, NetBIOS normally runs over TCP/IP via the NetBIOS over TCP/IP (NBT) protocol. This results in each computer in the network having both an IP address and a NetBIOS name corresponding to a host name. NetBIOS is also used for identifying system names in TCP/IP (Windows). Simply stated, it is a protocol that allows communication of data for files and printers through the Session Layer of the OSI Model in a LAN.

StarLAN was the first IEEE 802.3 standard for Ethernet over twisted pair wiring. It was standardized by the IEEE Standards Association as 802.3e in 1986, as the 1BASE5 version of Ethernet. The StarLAN Task Force was chaired by Bob Galin.

Ungermann-Bass, also known as UB and UB Networks, was a computer networking company in the 1980s to 1990s. Located in Santa Clara, California, UB was the first large networking company independent of any computer manufacturer. Along with competitors 3Com and Sytek, UB was responsible for starting the networking business in Silicon Valley in 1979. UB was founded by Ralph Ungermann and Charlie Bass. John Davidson, vice president of engineering, was one of the creators of NCP, the transport protocol of the ARPANET before TCP.

LattisNet was a family of computer networking hardware and software products built and sold by SynOptics Communications during the 1980s. Examples were the 1000, 2500 and 3000 series of LattisHub network hubs. LattisNet was the first implementation of 10 Megabits per second local area networking over unshielded twisted pair wiring in a star topology.

Madge Networks NV was a networking technology company founded by Robert Madge, and is best known for its work with Token Ring. It was a global leader and pioneer of high-speed networking solutions in the mid-1990s, and also made significant contributions to technologies such as Asynchronous Transfer Mode (ATM) and Ethernet.

<span class="mw-page-title-main">Computer network</span> Network that allows computers to share resources and communicate with each other

A computer network is a set of computers sharing resources located on or provided by network nodes. Computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are made up of telecommunication network technologies based on physically wired, optical, and wireless radio-frequency methods that may be arranged in a variety of network topologies.

<span class="mw-page-title-main">Token Ring</span> Technology for computer networking

Token Ring is a physical and data link layer computer networking technology used to build local area networks. It was introduced by IBM in 1984, and standardized in 1989 as IEEE 802.5. It uses a special three-byte frame called a token that is passed around a logical ring of workstations or servers. This token passing is a channel access method providing fair access for all stations, and eliminating the collisions of contention-based access methods.

HYPERchannel, sometimes rendered Hyperchannel, was a local area networking system for mainframe computers, especially supercomputers, introduced by Network Systems Corporation in the 1970s. It ran at the then-fast speed of 50 Mbits/second, performance that would not be matched by commodity hardware until the introduction of Fast Ethernet in 1995. HYPERchannel ran over very thick coax cable or fibre optic extensions and required adaptor hardware the size of a minicomputer. The networking protocol was entirely proprietary. Solutions for Control Data, IBM and Cray computers were their primary products, but a wide variety of support emerged in the 1980s, including DEC VAX and similar superminicomputers.

<span class="mw-page-title-main">Sniffer (protocol analyzer)</span> Network packet and protocol analyzer

The Sniffer was a computer network packet and protocol analyzer developed and first sold in 1986 by Network General Corporation of Mountain View, CA. By 1994 the Sniffer had become the market leader in high-end protocol analyzers. According to SEC 10-K filings and corporate annual reports, between 1986 and March 1997 about $933M worth of Sniffers and related products and services had been sold as tools for network managers and developers.

References

  1. ↑ Gary A. Donahue (June 2007). Network Warrior. O'Reilly. p. 5.
  2. ↑ Samuel F. Mendicino (1970-12-01). "Octopus: The Lawrence Radiation Laboratory Network". Rogerdmoore.ca. Archived from the original on 2011-07-06.
  3. ↑ Mendicino, S. F. (29 Nov 1970). "THE LAWRENCE RADIATION LABORATORY OCTOPUS". Courant Symposium Series on Networks. Osti.gov. OSTI   4045588.
  4. ↑ The History of Ethernet. NetEvents.tv. 2006. Retrieved September 10, 2011. Archived at Ghostarchive and the Wayback Machine
  5. ↑ "Ethernet Prototype Circuit Board". Smithsonian National Museum of American History. 1973. Archived from the original on October 28, 2014. Retrieved September 2, 2007.
  6. ↑ "A brief informal history of the Computer Laboratory". University of Cambridge. 20 December 2001. Archived from the original on 13 November 2010.
  7. ↑ "ARCNET Timeline" (PDF). ARCNETworks magazine. Fall 1998. Archived from the original (PDF) on 2010-04-14.
  8. ↑ Lamont Wood (2008-01-31). "The LAN turns 30, but will it reach 40?". Computerworld. Archived from the original on 2016-06-30. Retrieved 2016-06-02.
  9. 1 2 European Parliament Archives (January 25, 2021). "Voting system Tender Specifications - 1979". Archived from the original on June 16, 2021.
  10. ↑ Metcalfe, Robert (Dec 27, 1993). "Will The Year of the ISDN be 1994 or 1995?". InfoWorld. 15 (52). Archived from the original on June 14, 2021. Retrieved June 14, 2021. 'The Year of The LAN' is a long-standing joke, and I freely admit to being the comedian that first declared it in 1982...
  11. ↑ "Quotes in 1999". Cafe au Lait Java News and Resources. Archived from the original on 2016-04-14. Retrieved 2011-02-25. ...you will remember numerous computer magazines, over numerous years, announcing 'the year of the LAN.'
  12. ↑ Herot, Christopher. "Christopher Herot's Weblog" . Retrieved 2023-10-21. ...a bit like the Year of the LAN which computer industry pundits predicted for the good part of a decade...
  13. ↑ Wayne Spivak (2001-07-13). "Has Microsoft Ever Read the History Books?". VARBusiness. Archived from the original on 2011-07-16.
  14. ↑ Scott, W. Ross (May 1, 1984). "Updated Local Area Network Demonstration Plan". MITRE Corporation Working Paper (WP83W00222R1).
  15. ↑ Havard (II.), Richard (17 June 1986). MITRENET: A Testbed Local Area Network at DTNSRDC. Ft. Belvoir Defense Technical Information Center: Defense Technical Information Center. p. i.
  16. ↑ Scott, W. Ross; Cavedo, Robert F. (September 1, 1984). "Local Area Network Demonstration Procedures". MITRE Corporation Working Paper (WP83W00595).
  17. ↑ Scott, W. Ross (August 1, 1984). "Local Area Network Alternative "A" Demonstration Analysis (DRAFT)". MITRE Corporation Working Paper (WP84W00281).
  18. ↑ "Retro Isle - Acorn Econet". www.retroisle.com. Retrieved 2020-10-28.
  19. ↑ "Chris's Acorns: Econet". chrisacorns.computinghistory.org.uk. Retrieved 2020-10-28.
  20. ↑ J. Noel Chiappa (April–June 2014). "Early Token Ring Work at MIT". IEEE Annals of the History of Computing . 36 (2): 80–85. doi: 10.1109/MAHC.2014.14 . S2CID   30761524.
  21. ↑ Pelkey, James. "14.18 Proteon in Chapter 14 - Internetworking: Emergence 1985-1988". The History of Computer Communications.
  22. ↑ "IBM TOKEN-RING NETWORK". www-01.ibm.com. 1985-10-15. Retrieved 2021-03-11.
  23. ↑ Crabb, Don (24 March 1986). "Major Vendors Differ On Network Approach". InfoWorld . Vol. 8, no. 12. p. 27.
  24. ↑ "InfoWorld". 21 November 1988.
  25. ↑ IEEE 802.3 Local Area Network considerations. IBM. GG22-9422-0.
  26. ↑ David R. Boggs; Jeffrey C. Mogul; Christopher A. Kent (1988). "Measured capacity of an Ethernet: myths and reality" (PDF). ACM SIGCOMM Computer Communication Review. 25 (1): 123–136. doi:10.1145/205447.205460. S2CID   52820607.
  27. ↑ Internetworking Technologies Handbook. Cisco Press. 2004. ISBN   978-1-58705-119-7.
  28. ↑ "IEEE Standards Association".
  29. ↑ Urs Von Burg; Martin Kenny (December 2003). "Sponsers, [sic] Communities, and Standards: Ethernet vs. Token Ring In The Local Area Networking Business" (PDF). Industry and Innovation. 10 (4). Taylor & Francis Ltd: 351–375. doi:10.1080/1366271032000163621. S2CID   153804163. Archived from the original (PDF) on 2018-02-19.
  30. ↑ Mark Miller (March 21, 1994). "Wading Through Plethora of Options Poses Challenge for Life on the Fast LAN". Network World. pp. 41, 44, 46–49. Retrieved August 15, 2013.
  31. ↑ A. Selvarajan; Subrat Kar; T. Srinivas (2003). Optical Fiber Communication: Principles and Systems. Tata McGraw-Hill Education. pp. 241–249. ISBN   978-1-259-08220-7.
  32. ↑ "Italian TV network RAI on the voting system". 25 January 2021. Archived from the original on 17 January 2023.
  33. ↑ "Big pipe on campus: Ohio institutions implement a 10-Gigabit Ethernet switched-fiber backbone to enable high-speed desktop applications over UTP copper", Communications News, 2005-03-01, archived from the original on 2016-09-10, As alternatives were considered, fiber to the desk was evaluated, yet only briefly due to the added costs for fiber switches, cables and NICs. "Copper is still going to be a driving force to the desktop for the future, especially as long as the price for fiber components remains higher than for copper."
  34. ↑ "A Review of the Basic Components of a Local Area Network (LAN)". NetworkBits.net. Archived from the original on 2020-10-26. Retrieved 2008-04-08.
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