Local area network

Source: Wikipedia, the free encyclopedia.
"LAN" redirects here. For other uses, see Lan.
fixed-line
means.

A local area network (LAN) is a

network equipment
and interconnects locally managed. LANs facilitate the distribution of data and sharing network devices, such as printers.

The LAN contrasts the wide area network (WAN), which not only covers a larger geographic distance, but also generally involves leased telecommunication circuits or Internet links. An even greater contrast is the Internet, which is a system of globally connected business and personal computers.

Ethernet and Wi-Fi are the two most common technologies used for local area networks; historical network technologies include ARCNET, Token Ring, and LocalTalk.

Computer network types
by scale

Cabling

RJ45 compatible terminations. This medium provides physical connectivity between the Ethernet
interfaces present on a large number of IP-aware devices. Depending on the grade of cable and quality of installation, speeds of up to 10 Mbit/s, 100 Mbit/s, 1 Gbit/s, or 10 Gbit/s are supported.

Wireless LAN

Further information: IEEE 802.11

In a

hotspot
service.

Infrastructure and technicals

star topology
.

Simple LANs in office or school buildings generally consist of cabling and one or more

network intrusion detection.[7] A wireless access point is required for connecting wireless devices to a network; when a router includes this device, it is referred to as a wireless router
.

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. A network bridge binds two different LANs or LAN segments to each other, often in order to grant a wired-only device access to a wireless network medium.

mesh and star. The star topology is the most common in contemporary times. Wireless LAN (WLAN) also has its topologies: independent basic service set (IBSS, an ad-hoc network) where each node connects directly to each other (this is also standardized as Wi-Fi Direct), or basic service set (BSS, an infrastructure network that uses an wireless access point).[8]

Various topologies that may be used in a centralised wired LAN: star, ring, bus, and tree

Network layer configuration

internet.[10]

Protocols

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 for almost all local area networks today.

Connection to other LANs

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).

Connection to the Internet

Local area networks may be connected to the

fiber to the home for running fiber-optic cables directly into a house or office building, or alternatively a cellular modem or satellite dish in the latter non-fixed cases. With Internet access, the Internet service provider (ISP) would grant a single WAN-facing IP address to the network. A router is configured with the provider's IP address on the WAN interface, which is shared among all devices in the LAN by network address translation
.

A

switch
.

The

Powerline standard, which provide high-speed (up to 1 Gbit/s) local area networking over existing home wiring, are examples of home networking technology designed specifically for IPTV delivery.[12][relevant?
]

History and development of LAN

Early installations

Home networking standards
IEEE standardized
ITU-T recommendation

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.[13][14]

A number of experimental and early commercial LAN technologies were developed in the 1970s.

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.[21]

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".[22][23][24]

Competing standards

In practice, the concept was marred by the proliferation of incompatible

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

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.[25]

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.

FTP, and a Defense Department teleconferencing application.[28] 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.[29] However, WWMCCS was superseded by the Global Command and Control System
(GCCS) before that could happen.

During the same period,

IPX, AppleTalk, NBF
, and other protocols used by the early PC LANs.

4 computers in 1981.[30][31]

Further development

In the 1980s, several token ring network implementations for LANs were developed.

Mbit/s.[36] IBM claimed that their token ring systems were superior to Ethernet, especially under load, but these claims were debated;[37][38] while the slow but inexpensive AppleTalk was popular for Macs, in 1987 InfoWorld said, "No LAN has stood out as the clear leader, even in the IBM world".[39] IBM's implementation of token ring was the basis of the IEEE 802.5 standard.[40] A 16 Mbit/s version of Token Ring was standardized by the 802.5 working group in 1989.[41] IBM had market dominance over Token Ring, for example, in 1990, IBM equipment was the most widely used for Token Ring networks.[42]

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

Marvell Technology Group), and 3Com.[43] FDDI installations have largely been replaced by Ethernet deployments.[44]

See also

References

  1. ^ Gary A. Donahue (June 2007). Network Warrior. O'Reilly. p. 5.
  2. ^ Wood, Roy (2024-04-01). "Computer Hardware, Software, and Networks". Introduction to Information Systems Management.
  3. ^ "What is a LAN? Local Area Network". Cisco. Retrieved 2024-12-04.
  4. ^ "When Did WiFi Become Popular | Beambox". beambox.com. Retrieved 2025-01-27.
  5. ^ "What are 802.11 Standards?". CBT Nuggets. Retrieved 2025-01-27.
  6. ^ “Discover and Learn,” WiFi Alliance, http://www.wi-fi.org/discover_and_learn.php Archived 2010-07-04 at the Wayback Machine (accessed June 30, 2010).
  7. ^ "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.
  8. ^ "Network Topologies". www3.nd.edu. Retrieved 2024-12-11.
  9. ^ What is DHCP? Archived 2013-12-07 at the Wayback Machine. whatismyip.com.
  10. doi:10.23956/ijarcsse/SV7I5/208 (inactive 6 July 2025).{{cite journal}}: CS1 maint: DOI inactive as of July 2025 (link) CS1 maint: multiple names: authors list (link) CS1 maint: numeric names: authors list (link
    )
  11. ^ "Configuration example for connecting a LAN to the Internet through an ADSL modem". support.hpe.com. Retrieved 2024-12-06.
  12. ISBN 9781466557529. Archived
    from the original on 2015-10-17. Retrieved 2014-05-19.
  13. ^ Samuel F. Mendicino (1970-12-01). "Octopus: The Lawrence Radiation Laboratory Network". Rogerdmoore.ca. Archived from the original on 2011-07-06.
  14. OSTI 4045588
    .
  15. ^ The History of Ethernet. NetEvents.tv. 2006. Retrieved September 10, 2011. Archived at Ghostarchive and the Wayback Machine
  16. ^ "Ethernet Prototype Circuit Board". Smithsonian National Museum of American History. 1973. Archived from the original on October 28, 2014. Retrieved September 2, 2007.
  17. ^ "A brief informal history of the Computer Laboratory". University of Cambridge. 20 December 2001. Archived from the original on 13 November 2010.
  18. ^ "ARCNET Timeline" (PDF). ARCNETworks magazine. Fall 1998. Archived from the original (PDF) on 2010-04-14.
  19. ^ 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.
  20. ^ European Parliament Archives (January 25, 2021). "Voting system Tender Specifications - 1979". Archived from the original on June 16, 2021.
  21. ^ "Italian TV network RAI on the voting system". 25 January 2021. Archived from the original on 17 January 2023.
  22. ^ 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...
  23. ^ "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.'
  24. ^ 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...
  25. ^ Wayne Spivak (2001-07-13). "Has Microsoft Ever Read the History Books?". VARBusiness. Archived from the original on 2011-07-16.
  26. ^ Scott, W. Ross (May 1, 1984). "Updated Local Area Network Demonstration Plan". MITRE Corporation Working Paper (WP83W00222R1).
  27. ^ 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.
  28. ^ Scott, W. Ross; Cavedo, Robert F. (September 1, 1984). "Local Area Network Demonstration Procedures". MITRE Corporation Working Paper (WP83W00595).
  29. ^ Scott, W. Ross (August 1, 1984). "Local Area Network Alternative "A" Demonstration Analysis (DRAFT)". MITRE Corporation Working Paper (WP84W00281).
  30. ^ "Retro Isle - Acorn Econet". www.retroisle.com. Retrieved 2020-10-28.
  31. ^ "Chris's Acorns: Econet". chrisacorns.computinghistory.org.uk. Retrieved 2020-10-28.
  32. S2CID 30761524
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  33. ^ Pelkey, James. "14.18 Proteon in Chapter 14 - Internetworking: Emergence 1985-1988". The History of Computer Communications.
  34. ^ "IBM Token-Ring Network". IBM. 1985-10-15. Retrieved 2025-03-26.
  35. ^ Crabb, Don (24 March 1986). "Major Vendors Differ On Network Approach". InfoWorld. Vol. 8, no. 12. p. 27.
  36. ^ "InfoWorld". 21 November 1988.
  37. ^ IEEE 802.3 Local Area Network considerations. IBM. GG22-9422-0.
  38. S2CID 52820607
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  39. ^ Satchell, Stephen (1987-08-17). "IBM PS/2 Model 25". Short Looks. InfoWorld. Vol. 9, no. 33. p. 44. Retrieved 2025-05-25.
  40. ISBN 978-1-58705-119-7
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  41. ^ "IEEE Standards Association". Archived from the original on August 17, 2022.
  42. S2CID 153804163. Archived from the original
    (PDF) on 2018-02-19.
  43. ^ 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.
  44. ISBN 978-1-259-08220-7
    .
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