计算机英语Computer networkWord文件下载.docx
- 文档编号:15758368
- 上传时间:2022-11-15
- 格式:DOCX
- 页数:11
- 大小:117.48KB
计算机英语Computer networkWord文件下载.docx
《计算机英语Computer networkWord文件下载.docx》由会员分享,可在线阅读,更多相关《计算机英语Computer networkWord文件下载.docx(11页珍藏版)》请在冰豆网上搜索。
∙1History
∙2Purpose
∙3Networkclassification
o3.1Connectionmethod
o3.2Wiredtechnologies
o3.3Wirelesstechnologies
o3.4Scale
o3.5Functionalrelationship(networkarchitecture)
o3.6Networktopology
∙4Typesofnetworksbasedonphysicalscope
o4.1Localareanetwork
▪4.1.1Personalareanetwork
▪4.1.2Homeareanetwork
o4.2Wideareanetwork
▪4.2.1Campusnetwork
o4.3Metropolitanareanetwork
▪4.3.1Enterpriseprivatenetwork
▪4.3.2Virtualprivatenetwork
▪4.3.3Internetwork
o4.4Backbonenetwork
▪4.4.1Globalareanetwork
▪4.4.2Internet
▪4.4.3Intranetsandextranets
▪4.4.4Overlaynetwork
∙5Basichardwarecomponents
o5.1Networkinterfacecards
o5.2Repeaters
o5.3Bridges
o5.4Switches
o5.5Routers
o5.6Firewalls
∙6References
∙7Furtherreading
History
EarlynetworksofcommunicatingcomputersincludedthemilitaryradarsystemSemi-AutomaticGroundEnvironment(SAGE)anditsrelativethecommercialairlinereservationsystemSemi-AutomaticBusinessResearchEnvironment(SABRE),startedinthelate1950s.[1][2]Inthe1960s,theAdvancedResearchProjectsAgency(ARPA)startedfundingthedesignoftheAdvancedResearchProjectsAgencyNetwork(ARPANET)fortheUnitedStatesDepartmentofDefense.Developmentofthenetworkbeganin1969,basedondesignsdevelopedduringthe1960s.[3]TheARPANETevolvedintothemodernInternet.
Purpose
Computernetworkscanbeusedforavarietyofpurposes:
∙Facilitatingcommunications.Usinganetwork,peoplecancommunicateefficientlyandeasilyviaemail,instantmessaging,chatrooms,telephone,videotelephonecalls,andvideoconferencing.
∙Sharinghardware.Inanetworkedenvironment,eachcomputeronanetworkmayaccessandusehardwareresourcesonthenetwork,suchasprintingadocumentonasharednetworkprinter.
∙Sharingfiles,data,andinformation.Inanetworkenvironment,authorizedusermayaccessdataandinformationstoredonothercomputersonthenetwork.Thecapabilityofprovidingaccesstodataandinformationonsharedstoragedevicesisanimportantfeatureofmanynetworks.
∙Sharingsoftware.Usersconnectedtoanetworkmayrunapplicationprogramsonremotecomputers.
∙Informationpreservation.
∙Easycommunication
Networkclassification
Thefollowinglistpresentscategoriesusedforclassifyingnetworks.
Connectionmethod
Computernetworkscanbeclassifiedaccordingtothehardwareandsoftwaretechnologythatisusedtointerconnecttheindividualdevicesinthenetwork,suchasopticalfiber,Ethernet,wirelessLAN,HomePNA,powerlinecommunicationorG.hn.
EthernetasitisdefinedbyIEEE802utilizesvariousstandardsandmediumsthatenablecommunicationbetweendevices.Frequentlydeployeddevicesincludehubs,switches,bridges,orrouters.WirelessLANtechnologyisdesignedtoconnectdeviceswithoutwiring.Thesedevicesuseradiowavesorinfraredsignalsasatransmissionmedium.ITU-TG.hntechnologyusesexistinghomewiring(coaxialcable,phonelinesandpowerlines)tocreateahigh-speed(upto1Gigabit/s)localareanetwork.
Wiredtechnologies
∙Twistedpairwireisthemostwidelyusedmediumfortelecommunication.Twisted-paircablingconsistofcopperwiresthataretwistedintopairs.Ordinarytelephonewiresconsistoftwoinsulatedcopperwirestwistedintopairs.Computernetworkingcablingconsistof4pairsofcoppercablingthatcanbeutilizedforbothvoiceanddatatransmission.Theuseoftwowirestwistedtogetherhelpstoreducecrosstalkandelectromagneticinduction.Thetransmissionspeedrangesfrom2millionbitspersecondto100millionbitspersecond.TwistedpaircablingcomesintwoformswhichareUnshieldedTwistedPair(UTP)andShieldedtwisted-pair(STP)whichareratedincategorieswhicharemanufacturedindifferentincrementsforvariousscenarios.
∙Coaxialcableiswidelyusedforcabletelevisionsystems,officebuildings,andotherwork-sitesforlocalareanetworks.Thecablesconsistofcopperoraluminumwirewrappedwithinsulatinglayertypicallyofaflexiblematerialwithahighdielectricconstant,allofwhicharesurroundedbyaconductivelayer.Thelayersofinsulationhelpminimizeinterferenceanddistortion.Transmissionspeedrangefrom200milliontomorethan500millionbitspersecond.
∙Opticalfibercableconsistsofoneormorefilamentsofglassfiberwrappedinprotectivelayersthatcarriesadatabyme
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 计算机英语Computer network 计算机 英语 Computer