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ELEVENTHEDITIONELECTRONICCOMMERCEGARYP.SCHNEIDERTechnologyInfrastructure:TheInternetandtheWorldWideWebChapter2©CengageLearning2015LearningObjectivesInthischapter,youwilllearn:•Abouttheorigin,growth,andcurrentstructureoftheInternet•Howpacket-switchednetworksarecombinedtoformtheInternet•HowInternet,e-mail,andWebprotocolswork•AboutInternetaddressingandhowWebdomainnamesareconstructed©CengageLearning201522LearningObjectives(cont’d.)•AboutthehistoryanduseofmarkuplanguagesontheWeb•HowHTMLtagsandlinkswork•AbouttechnologiespeopleandbusinessesusetoconnecttotheInternet•AboutInternet2andtheSemanticWeb©CengageLearning201533Introduction•AgrowingnumberofInternetusersareusingsmartphoneortablet–Smartphonesaretypicallyonlytheaccessmethodindevelopingcountries•HistoryofInternet-capablemobilephones–Firstintroducedinlate-1990s•Slow,unreliableservice,nokeyboards–2001:Treo,Blackberryintroduced–2009:Allmajorphonemanufacturershadproducts–2011-2013:Lowerpricephonestargeteddevelopingmarkets©CengageLearning20154TheInternetandtheWorldWideWeb•Computernetwork–Technologyallowingpeopletoconnectcomputers•Internet(capital“I)–Interconnectedglobalcomputernetworks•internet(small“i”)–Groupofinterconnectedcomputernetworks•Basictechnologystructure–Supportsnetworks,theInternet,ande-commerce©CengageLearning201555TheInternetandtheWorldWideWeb(cont’d.)•WorldWideWeb(Web)–SubsetofInternetcomputers–Includeseasy-to-useinterfaces©CengageLearning201566OriginsoftheInternet•Early1960s–DefenseDepartmentnuclearattackconcerns–Powerfulcomputers(largemainframes)–Leasedtelephonecompanylines•Singleconnection–Singleconnectionrisksolution•Communicateusingmultiplechannels(packets)•1969AdvancedResearchProjectsAgency(ARPA)–Packetnetworkconnectedfourcomputers•ARPANET:earliestnetwork(becametheInternet)•Academicresearchuse(1970sand1980s)©CengageLearning20157NewUsesfortheInternet•DefenseDepartmentnetwork:theoriginalgoal–Tocontrolweaponssystems;transferresearchfiles•1970s:otheruses–E-mail(1972)–Networkingtechnology•Remotefiletransferandcomputeraccess–Mailinglists•1979:Usenet(User’sNewsNetwork)–Readandpostarticles–Newsgroups(topicareas)©CengageLearning20158NewUsesfortheInternet(cont’d.)•LimitedInternetuse–Researchandacademiccommunities•1979–1989–Networkapplicationsimprovedandtested–DefenseDepartment’snetworkingsoftware•Gainedwideracademicandresearchinstitutionuse•Commoncommunicationsnetworkbenefitrecognized–Securityproblemsrecognized•1980s:personalcomputeruseexplosion–Academicandresearchnetworksmerged©CengageLearning20159CommercialUseoftheInternet•NationalScienceFoundation(NSF)–Providedfunding–Prohibitedcommercialnetworktraffic•Businessesturnedtocommerciale-mailproviders•Largerfirmsbuiltnetworks(leasedtelephonelines)•1989:NSFpermittedtwocommerciale-mailservices(MCIMailandCompuServe)–Commercialenterprisescouldsende-mail–Research,educationcommunitiessente-maildirectlytoMCIMailandCompuServe©CengageLearning201510GrowthoftheInternet•1991–FurthereasingofcommercialInternetactivityrestrictions•1995:privatizationoftheInternet–Operationsturnedovertoprivatelyownedcompanies•Internetbasedonfournetworkaccesspoints(NAPs)•Networkaccessproviders–SellInternetaccessrightsdirectlytolargercustomers–UseInternetserviceproviders(ISPs)•Selltosmallerfirmsandindividuals©CengageLearning201511GrowthoftheInternet(cont’d.)•Internethosts:directlyconnectedcomputers•Internetgrowth–Oneofthemostsignificanttechnologicalandsocialaccomplishmentsoflastmillennium–Nearlyeverycountryinvolved–Usedbymillionsofpeople–Billionsofdollarschangehandsyearly©CengageLearning201512©CengageLearning201513FIGURE2-1GrowthoftheInternet©CengageLearning2015TheInternetofThings•DevicescanbeconnectedtotheInternet–Controlledremotely–Examples:sensors,switches,opticalscanners•TheInternetofthings–Termusedfortheseconnecteddevices–Estimatedsizeisninebillion–Projectedtoreach35billionby2020©CengageLearning201514Packet-SwitchedNetworks•Localareanetwork(LAN)–Networkofcomputerslocatedclosetogether•Wideareanetworks(WANs)–Networksofcomputersconnectedovergreaterdistances•Circuit–Combinationoftelephonelinesandclosedswitchesconnectingthemtoeachother•Circuitswitching–Centrallycontrolled,single-connectionmodel•Singleelectricalpathbetweencallerandreceiver©CengageLearning201515Packet-SwitchedNetworks(cont’d.)•Circuitswitching(cont’d.)–Workswellfortelephonecalls–Doesnotworkaswellfor:•SendingdataacrosslargeWANandinterconnectednetwork(Internet)•Circuit-switchednetworkproblem–Connectedcircuitfailure•Causesinterruptedconnectionanddataloss•Solution–Packetswitching:movedatabetweentwopoints©CengageLearning201516Packet-SwitchedNetworks(cont’d.)•Packet-switchednetwork–Packets•Smallpieceslabeledelectronically(origin,sequence,anddestinationaddress)•Travelalonginterconnectednetworks•Cantakedifferentpaths•Mayarriveoutoforder–Destinationcomputer•Collectspackets•Reassemblesoriginalfileore-mailmessage©CengageLearning201517RoutingPackets•Routingcomputers–Decidehowbesttoforwardeachpacket–Alsoknownasrouters,gatewaycomputers,borderrouters•GatewayfromLANorWANtoInternet•Borderbetween
本文标题:电子商务概论_PPT_ch02
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