LAN/WAN Networking:An Overview

Chapter 1

Learning ObjectivesDefine and identify the different types of networks

Describe the history of LANs and WANs

Discuss LAN and WAN integration, including the basic functions of bridges, routers, gateways, and switches

Describe network protocol integration methods

Explain the preparatory steps of network design

Computer NetworkSystem of computers, print devices, and computer software linked by communications cabling or radio waves

Typically classified according to:Reach and complexity

Protocols and topologies

Network Communication

Network Types DefinedLocal area networks

Metropolitan area networks

Wide area networks

Local Area Network (LAN)Series of interconnected computers, printing devices, and other computer equipment that share hardware and software resources

Service area usually limited to a given office area, floor, or building

Example of a LAN

Metropolitan Area NetworkLinks multiple LANs in a large city or metropolitan region

Typically uses fiber-optic connections

Example of a MAN

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

Network ClassificationEnterprise network

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

Enterprise Network

Identifying a Network TypeCommunications medium

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

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

TopologyPhysical layout of cable and logical path

Network typePrivate versus public

Events that Led up to LANs and WANs

1800sOersted

Morse

Undersea cable

Pony Express

Bell

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

LAN/WAN History: 1960sFirst WAN

Hypertext

Use of fiber optics for phone signals

Beginning of ARPANET

Packets and packet switching

UNIX

Telecommunications equipment

First IMP prototype

LAN/WAN History: 1970sEthernet

ARPANET - 15 sites

E-mail

Terminal emulation

International connections to ARPANET

Telecommunications conversion from analog to digital

X.25

First wireless gateway

Internet Protocol

LSI and VLSI chips

ICCB

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

LAN/WAN History: 1990sARPANET retired

SS7 technology

NSFNET opened to commercial use

First cyberbank

Internet service providers

Over 16 million Internet hosts

LAN/WAN History: 2000sIPv6 used for Internet2 backbone communications

Video and radio capability

Prices of 1-Gbps devices fall as competition increases

LAN/WAN Integration1960s-1980s

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

NetworksAllow connections to many devices

Enable distributed client/server computing

Using SNA to Directly Connect without a Network

LAN/WAN IntegrationBecoming more advanced through networking devices

Bridges

Routers

Gateways

Switches

BridgesConnect different LANs or LAN segments using the same access method

RoutersConnect networks having the same or different access methods and media

Forward packets and frames to networks by using a decision-making process based on:

Routing table data

Discovery of most efficient routes

Preprogrammed information from network administrator

Routers

GatewaysEnable communications between two different types of networked systems

Gateways

SwitchesLink network segments

Forward and filter frames between segments

Integrating Data Between LANs and WANs

Translation

Encapsulation

LAN emulation (LANE)

Network Design IntroductionHow networks work in terms of protocols, access methods, and topologies

Physical equipment used in LANs and WANs

Basic network design principlesUsing structured wiring and structured networking techniques

Designing for multimedia and client/server applications

Taking advantage of LAN and WAN device characteristics

continued…

Network Design IntroductionAssess characteristics of the organization that affect network design

Types and locations of computers

Software applications and resources required

Business patterns

High and low network use periods

Designing to facilitate troubleshooting

Type of security required

Anticipated growth

Chapter SummaryBasic networking terms and concepts

History and evolution of local and wide area networking technologies

Different methods of integrating short and long distance information networks

How to prepare for designing networks