A local-area network is a computer network covering a small geographic area, like a home, office, or group of buildings e. A computer network is a group of interconnected Computers. Networks may be classified according to a wide variety of characteristics g. a school. The defining characteristics of LANs, in contrast to wide-area networks (WANs), include their much higher data-transfer rates, smaller geographic range, and lack of a need for leased telecommunication lines. Wide Area Network ( WAN) is a Computer network that covers a broad area (i A leased line is a symmetric Telecommunications line connecting two locations

Ethernet over unshielded twisted pair cabling, and Wi-Fi are the two most common technologies currently, but ARCNET, Token Ring and many others have been used in the past. Ethernet is a family of frame -based Computer networking technologies for Local area networks (LANs Twisted pair Cabling is a form of wiring in which two conductors (two halves of a single circuit) are wound together for the purposes of canceling out Wi-Fi (ˈwaɪfaɪ is the trade name for the popular wireless technology used ARCNET (also CamelCased as ARCnet, an Acronym from Attached Resource Computer NETwork is a Local area network ( LAN) protocol Token ring Local area network (LAN technology is a local area network protocol which resides at the Data link layer

History

The first LAN put into service occurred in 1964 at the Livermore Laboratory to support atomic weapons research. LANs spread to the public sector in the late 1970s and were used to create high-speed links between several large central computers at one site. Of many competing systems created at this time, Ethernet and ARCNET were the most popular. ARCNET (also CamelCased as ARCnet, an Acronym from Attached Resource Computer NETwork is a Local area network ( LAN) protocol

The development and proliferation of CP/M and then DOS-based personal computers meant that a single site began to have dozens or even hundreds of computers. CP/M (Control Program for Microcomputers is an Operating system originally created for Intel 8080 / 85 based Microcomputers by Gary Kildall DOS, short for "Disk Operating System" is a shorthand term for several closely related Operating systems that dominated the IBM PC compatible market A personal computer ( PC) is any Computer whose original sales price size and capabilities make it useful for individuals and which is intended to be operated The initial attraction of networking these was generally to share disk space and laser printers, which were both very expensive at the time. There was much enthusiasm for the concept and for several years, from about 1983 onward, computer industry pundits would regularly declare the coming year to be “the year of the LAN”.

In reality, the concept was marred by proliferation of incompatible physical layer and network protocol implementations, and confusion over how best to share resources. The Physical Layer is the first level in the seven-layer OSI model of computer networking. In computing, a protocol is a convention or standard that controls or enables the connection Communication, and Data transfer between two computing Typically, each vendor would have its own type of network card, cabling, protocol, and network operating system. A network operating system (NOS is software that controls a network and its Message (e A solution appeared with the advent of Novell NetWare which provided even-handed support for the 40 or so competing card/cable types, and a much more sophisticated operating system than most of its competitors. NetWare is a Network operating system developed by Novell Inc Netware dominated^[1] the personal computer LAN business from early after its introduction in 1983 until the mid 1990s when Microsoft introduced Windows NT Advanced Server and Windows for Workgroups. Windows NT is a family of Operating systems produced by Microsoft, the first version of which was released in July 1993 Windows 31x was a major release of Microsoft Windows. Several editions were released between 1992 and 1994 succeeding Windows 3

Of the competitors to NetWare, only Banyan Vines had comparable technical strengths, but Banyan never gained a secure base. Banyan VINES (for Virtual Integrated NEtwork Service) was a Computer network Operating system and the set of computer Network protocols it used Microsoft and 3Com worked together to create a simple network operating system which formed the base of 3Com's 3+Share, Microsoft's LAN Manager and IBM's LAN Server. Microsoft Corporation is an American multinational Computer technology Corporation, which rose to dominate the Home computer The LAN Manager (not to be confused with NTLM) was a Network Operating System (NOS from Microsoft developed in cooperation with 3Com. IBM LAN Server started as a close cousin of Microsoft LAN Manager and first shipped in early 1988. None of these were particularly successful.

In this same timeframe, Unix computer workstations from vendors such as Sun Microsystems, Hewlett-Packard, Silicon Graphics, Intergraph, NeXT and Apollo were using TCP/IP based networking. Unix (officially trademarked as UNIX, sometimes also written as Unix with Small caps) is a computer A workstation, such as a Unix workstation, RISC workstation or Engineering workstation, is a high-end Microcomputer Sun Microsystems Inc ( is a multinational vendor of Computers computer components Computer software, and Information technology services Silicon Graphics Inc (commonly initialised to SGI, historically sometimes referred to as Silicon Graphics Computer Systems or SGCS) is a company Intergraph Corporation is a software company with 3879 employees worldwide (2008 NeXT Computer Inc (later NeXT Software Inc) was an American Computer company headquartered in Redwood City, California that The Internet Protocol Suite (commonly TCP/IP) is the set of Communications protocols used for the Internet and other similar networks Although this market segment is now much reduced, the technologies developed in this area continue to be influential on the Internet and in both Linux and Apple Mac OS X networking—and the TCP/IP protocol has now almost completely replaced IPX, AppleTalk, NBF and other protocols used by the early PC LANs. Linux (commonly pronounced ˈlɪnəks Mac OS X (mæk oʊ ɛs tɛn is a line of computer Operating systems developed marketed and sold by Apple Inc, the latest of which is pre-loaded on all currently Internetwork Packet Exchange ( IPX) is the OSI-model Network layer protocol in the IPX/SPX Protocol stack. AppleTalk is a proprietary suite of protocols developed by Apple Inc for networking computers NetBIOS Frames or NBF protocol is a non- Routable network- and transport-level data protocol most commonly used as one of the layers of Microsoft Windows

Technical aspects

Although switched Ethernet is now the most common data link layer protocol and IP as a network layer protocol, many different options have been used, and some continue to be popular in niche areas. Ethernet is a family of frame -based Computer networking technologies for Local area networks (LANs The Data Link Layer is Layer 2 of the seven-layer OSI model. It responds to service requests from the Network Layer and issues service requests to the The Internet Protocol ( IP) is a protocol used for communicating data across a Packet-switched Internetwork using the Internet Protocol The Network Layer is Layer 3 (of seven in the OSI model of networking In the field of Telecommunications, a communications protocol is the set of standard rules for data representation signaling authentication and error detection required to Smaller LANs generally consist of a one or more switches linked to each other - often with one connected to a router, cable modem, or DSL modem for Internet access. A router ('rautər in the USA 'rutər in the UK and Ireland, or either pronunciation in Australia and Canada is a Computer whose software and hardware are usually A cable modem is a type of Modem that provides access to a data signal sent over the Cable television infrastructure ADSL modem or DSL modem is a device used to connect a single Computer or Router to a DSL phone line in order to use an ADSL The Internet is a global system of interconnected Computer networks

Larger 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 to segregate traffic via VLANs. The Spanning Tree Protocol is an OSI layer-2 protocol that ensures a loop-free topology for any bridged LAN. A virtual LAN, commonly known as a VLAN, is a group of hosts with a common set of requirements that communicate as if they were attached to the Broadcast domain Larger LANS also contain a wide variety of network devices such as switches, firewalls, routers, load balancers, sensors and so on. ^[2]

LANs may have connections with other LANs via leased lines, leased services, or by 'tunneling' across the Internet using VPN technologies. The Internet is a global system of interconnected Computer networks Depending on how the connections are made, secured, and the distance involved they become a Metropolitan Area Network (MAN), a Wide Area Network (WAN), or a part of the internet.

See also

• Computer network - general overview
• Ethernet physical layer
• LAN Party
• Metropolitan area network
• Network card
• Wide area network

References

1. ^ Has Microsoft Ever Read the History Books? - IT Channel - IT Channel News by CRN and VARBusiness
2. ^ A Review of the Basic Components of a Local Area Network (LAN). A computer network is a group of interconnected Computers. Networks may be classified according to a wide variety of characteristics The Ethernet physical layer is the Physical layer component of the Ethernet standard A LAN party is a temporary sometimes spontaneous gathering of people together with their computers which they network together primarily for the purpose of playing multiplayer Metropolitan area network s or MAN s are large Computer networks usually spanning a city A Network card, Network Adapter, LAN Adapter or NIC (network interface card is a piece of Computer hardware designed to allow computers Wide Area Network ( WAN) is a Computer network that covers a broad area (i NetworkBits. net. Retrieved on 2008-04-08. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 217 - Roman Emperor Caracalla is Assassinated (and succeeded by his Praetorian

• LAN design and sizing