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LAN/WAN Networking:An Overview

Chapter 1

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Learning ObjectivesDefine and identify the different types of networksDescribe the history of LANs and WANsDiscuss LAN and WAN integration, including the basic functions of bridges, routers, gateways, and switchesDescribe network protocol integration methodsExplain the preparatory steps of network design

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Computer NetworkSystem of computers, print devices, and computer software linked by communications cabling or radio wavesTypically classified according to:

Reach and complexityProtocols and topologies

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Network Communication

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Network Types DefinedLocal area networksMetropolitan area networksWide area networks

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Local Area Network (LAN)Series of interconnected computers, printing devices, and other computer equipment that share hardware and software resourcesService area usually limited to a given office area, floor, or building

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Example of a LAN

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Metropolitan Area NetworkLinks multiple LANs in a large city or metropolitan regionTypically uses fiber-optic connections

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Example of a MAN

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Wide Area Network (WAN)Far-reaching system of networks that usually extends over 30 miles and often reaches across states and continents

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Network ClassificationEnterprise network

Combination of LANs, MANs, or WANs that provides users with an array of computer and network resources to complete different tasks

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Enterprise Network

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Identifying a Network TypeCommunications medium

Wire cable, fiber-optic cable, radio waves, microwavesProtocol

How networked data is formatted into discrete unitsHow each unit is transmitted and interpreted

TopologyPhysical layout of cable and logical path

Network typePrivate versus public

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Events that Led up to LANs and WANs

1800sOerstedMorseUndersea cablePony ExpressBell

1900sTranscontinental and transatlantic callsVoice digitizationElectronic digital computersTransistorsSputnikCommunications satellitesASCIIMass-produced minicomputers

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LAN/WAN History: 1960sFirst WANHypertextUse of fiber optics for phone signalsBeginning of ARPANETPackets and packet switchingUNIXTelecommunications equipmentFirst IMP prototype

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LAN/WAN History: 1970sEthernetARPANET - 15 sitesE-mailTerminal emulationInternational connections to ARPANET

Telecommunications conversion from analog to digitalX.25First wireless gatewayInternet Protocol LSI and VLSI chipsICCB

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LAN/WAN History: 1980sBITNETIBM’s PCDial-up modem technologyTCP and IP adopted as protocol suite for ARPANETFirst PC LANArrival of Internet

Internetwork hosts5,000 in 1986100,000 in 1989

“Cyberspace”T-carrier servicesNFSNETDesktop authoring and multimediaSNMP

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LAN/WAN History: 1990sARPANET retiredSS7 technologyNSFNET opened to commercial useFirst cyber-bankInternet service providersOver 16 million Internet hosts

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LAN/WAN History: 2000sIPv6 used for Internet2 backbone communicationsVideo and radio capabilityPrices of 1-Gbps devices fall as competition increases

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LAN/WAN Integration1960s-1980s

Direct connection to host mainframe using Systems Network Architecture (SNA) communications protocol

NetworksAllow connections to many devicesEnable distributed client/server computing

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Using SNA to Directly Connect without a Network

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LAN/WAN IntegrationBecoming more advanced through networking devices

BridgesRoutersGatewaysSwitches

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BridgesConnect different LANs or LAN segments using the same access method

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RoutersConnect networks having the same or different access methods and mediaForward packets and frames to networks by using a decision-making process based on:

Routing table dataDiscovery of most efficient routesPreprogrammed information from network administrator

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Routers

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GatewaysEnable communications between two different types of networked systems

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Gateways

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SwitchesLink network segmentsForward and filter frames between segments

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Integrating Data Between LANs and WANs

TranslationEncapsulationLAN emulation (LANE)

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Network Design IntroductionHow networks work in terms of protocols, access methods, and topologiesPhysical equipment used in LANs and WANsBasic network design principles

Using structured wiring and structured networking techniquesDesigning for multimedia and client/server applicationsTaking advantage of LAN and WAN device characteristics

continued…

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Network Design IntroductionAssess characteristics of the organization that affect network design

Types and locations of computersSoftware applications and resources requiredBusiness patternsHigh and low network use periodsDesigning to facilitate troubleshootingType of security requiredAnticipated growth

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Chapter SummaryBasic networking terms and conceptsHistory and evolution of local and wide area networking technologiesDifferent methods of integrating short and long distance information networksHow to prepare for designing networks