计算机网路原理讲义Chapter1pdf下载(2)

分组交换网路：数据报和虚电路时间分配：分钟教学方式：讨论讲授教学内容：Packetswitching:storeandforwardRRRLRRRL‰TakesLRsecondstotransmit(pushout)packetofLbitsontolinkorRbps‰Entirepacketmustarriveatrouterbeforeitcanbetransmittedonnextlink:storeandforward‰delay=LRExample:‰L=Mbits‰R=Mbps上海交通学院计算机大学计算机网路原理mdashmdash第一章‰delay=secPacketswitchednetworks:forwarding‰Goal:movepacketsthroughroutersfromsourcetodestination‰wersquollstudyseveralpathselection(ierouting)algorithms(chapter)‰datagramnetwork:‰destinationaddressinpacketdeterminesnexthop‰routesmaychangeduringsession‰analogy:driving,askingdirections‰virtualcircuitnetwork:‰eachpacketcarriestag(virtualcircuitID),tagdeterminesnexthop‰fixedpathdeterminedatcallsetuptime,remainsfixedthrucall‰routersmaintainpercallstateIntroductionNetworkTaxonomyTelecommunicationnetworksCircuitswitchednetworksFDMTDMPacketswitchednetworksNetworkswithVCsDatagramNetworksbullDatagramnetworkisnoteitherconnectionorientedorconnectionlessbullInternetprovidesbothconnectionoriented(TCP)andconnectionlessservices(UDP)toapps重点：数据报和虚电路的差别总结：本次课程的主要内容：网路核心上海交通学院计算机大学计算机网路原理mdashmdash第一章电路交换和分组交换分组交换网路：数据报和虚电路上次课程的主要内容接入网路作业：pReviewquestionsproblems上海交通学院计算机大学计算机网路原理mdashmdash第一章第章第学时本次课计划课时：学时教学要领：接入网路与前续课和后续课的关系：上面部份了解网路的基本概念了解了网路边沿和核心部份的功能这么网路边沿的设备怎样接入网路就成为摆在我们面前的问题。

这部份介绍接入网路常用的一些技术后续课程继续介绍连结网路设备常用的地理介质。主要教学环节：接入网路别墅用户接入技术公司接入技术无线接入技术教学过程：接入网路时间分配：分钟教学方式：提出问题讨论讲授教学内容：提问Q:Howtoconnectendsystemstoedgerouter‰residentialaccessnets上海交通学院计算机大学计算机网路原理mdashmdash第一章‰institutionalaccessnetworks(school,company)‰mobileaccessnetworksKeepinmind:‰bandwidth(bitspersecond)ofaccessnetwork‰sharedordedicated重点：终端用户是共享还是独用码率。别墅用户接入技术时间分配：分钟教学方式：讲授教学内容：Residentialaccess:pointtopointaccess‰DialupviamodemuptoKbpsdirectaccesstorouter(oftenless)Canrsquotsurfandphoneatsametime:canrsquotbeldquoalwaysonrdquo上海交通学院计算机大学计算机网路原理mdashmdash第一章‰ADSL:asymmetricdigitalsubscriberlineuptoMbpsupstream(todaytypicallykbps)uptoMbpsdownstream(todaytypicallyMbps)FDM:kHzMHzfordownstreamkHzkHzforupstreamkHzkHzforordinarytelephoneResidentialaccess:cablemodems‰HFC:hybridfibercoaxasymmetric:uptoMbpsdownstream,Mbpsupstream‰networkofcableandfiberattacheshomestoISProuterhomesshareaccesstorouter‰deployment:availableviacableTVcompanieshomecableheadendcabledistributionnetwork(simplified)Typicallyto,homeshomecableheadendcabledistributionnetwork(simplified)Typicallyto,homes上海交通学院计算机大学计算机网路原理mdashmdash第一章重点：码率是共享的还是独霸的？公司接入技术时间分配：分钟教学方式：讲授教学内容：Companyaccess:localareanetworks‰companyunivlocsharedordedicatedlalareanetwork(LAN)connectsendsystemtoedgerouterinkconnectsendsystemandrouters,GigabitEthernet‰Ethernet:Mbs,MbpLANs:chapter．无线接入技术homecableheadendcabledistributionnetwork(simplified)homecableheadendcabledistributionnetwork(simplified)上海交通学院计算机大学计算机网路原理mdashmdash第一章时间分配：分钟教学方式：讲授教学内容：Wirelessaccessnetworks‰sharedwirelessaccessnetworkconnectsendsystemtorouter‰viabasestationakaldquoaccesspointrdquob(WiFi):Mbpselessaccessatorhappenreleslink„ile(s)tobasestation„„‰wirelessLANs:‰‰widerareawir‰providedbytelcooper‰G~kbpsbullWillit‰WAPGPRSinEuropewistypicallyusedtoconnectmobalsousedasbackbonelinkmultipleaccessprotocolcoordinateslinkaccessbasestationmobilehostsrouterbasestationmobilehostsrouternetworkinfrastructurewirelesshostsbullbulllaptop,PDA,IPphonerunapplicationsmaybestationary(nonmobile)orbilitybullmobilendashwirelessdoesnotalwaysmeanmonetworkinfrastructurenetworkinfrastructurewirelesshostsbullbulllaptop,PDA,IPphonerunapplicationsmaybestationary(nonmobile)orbilitybullmobilendashwirelessdoesnotalwaysmeanmowirelesshostsbullbulllaptop,PDA,IPphonerunapplicationsmaybestationary(nonmobile)orbilitybullmobilendashwirelessdoesnotalwaysmeanmonetworkinfrastructurebasestationbulltypicallyconnectedtowirednetworkbullrelayresponsibleforsendingpacketsbetweenwirednetworkandwirelesshost(s)initsldquoareardquondasheg,celltowersaccesspointsnetworkinfrastructurenetworkinfrastructurebasestationbulltypicallyconnectedtowirednetworkbullrelayresponsibleforsendingpacketsbetweenwirednetworkandwirelesshost(s)initsldquoareardquondasheg,celltowersaccesspointsbasestationbulltypicallyconnectedtowirednetworkbullrelayresponsibleforsendingpacketsbetweenwirednetworkandwirelesshost(s)initsldquoareardquondasheg,celltowersaccesspoints上海交通学院计算机大学计算机网路原理mdashmdash第一章„variousdatarates,transmissiondistanceinfrastructuremode„networknhandoff:mobilechangesbasestationprovidingconnectionintowirednetworkAdhocmoderouteamongthemselvesLANExtension重点：无线接入网路和有线接入网路的不同应用范围networkinfrastructurenetworkinfrastructurenetworkinfrastructurebasestationconnectsmobilesintowirednnobasestationsnnodescanonlytransmittoothernodeswithinlinkcoveragennodesorganizethemselvesintoanetwork:WirelessLANApplications„„Crossbuildinginterconnect„NomadicAccess„AdhocnetworkingHomenetworksTypicalhomenetworkcomponents:‰ADSLorcablemodemallNAT‰routerfirew‰Ethernet上海交通学院计算机大学计算机网路原理mdashmdash第一章‰wirelessaccesspointwirelessaccesspointlaptopsrouterfirewall总结：本次课程的主要内容:接入网路别墅用户接入技术公司接入技术无线接入技术上次课程的主地理介质ISP和主干网要内容:作业：pReviewquestionswirelesscablemodemtofromcableheadendEthernetwirelessaccesspointlaptopsrouterfirewallwirelesscablemodemtofromcableheadendEthernet上海交通学院计算机大学计算机网路原理mdashmdash第一章第章第学时计划课时：学时学要领：地理介质ISP和主干网前续课和后续课的关系：上节课了解了用户接入网路常用的技术接下去接入网路选用的介质就是最为关切的问题。