university of toronto querying and visualizing the internetnew

《university of toronto querying and visualizing the internetnew》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、QueryingandVisualizingtheInternetAlbertoMendelzonUniversityofTorontohttp://db.toronto.edu:8020/aomweb/aom.htmlCopyright©AlbertoO.Mendelzon,1996UNIVERSITYOFTORONTOQUERYINGANDVISUALIZINGTHEINTERNET•IntroductionAnoverviewoftheInternetAccessinginformationontheInternet•TheWorld-WideWebH

2、ypertextThehttpprotocolTheHTMLlanguageFindinginformationintheWeb•QueryingtheWebResourcediscoveryGlobalinformationsystemsWebquerylanguages•VisualizingtheWebLargegraphvisualizationTheHy+visualizationsystemUNIVERSITYOFTORONTOWhatistheInternet?•Def:Aninternetisafederationofcomputernetw

3、orksthatspeaktheTCP/IPprotocols•Def:TheInternetisaglobalinternetthatconnectshomes,schools,universities,corporations,andgovernmentsinover60countries.Motivation:•Datacommunicationhasbecomeafundamentalpartofcomputing•Nosinglenetworkhardwareisgoodforallapplications•Usersdesireuniversal

4、interconnectionUNIVERSITYOFTORONTOHistory•1970’sPacketswitchingARPANET•1980ConversiontoTCP/IPTCP/IPbundledwithBerkeleyUnix•1985NSFNET,56KbpsbackboneDomainNameSystem•1992InternetSocietyANSNET,45MbpsbackboneUNIVERSITYOFTORONTOInternetArchitectureCooperativeinterconnectionofnetworksNe

5、tworkscommunicatethroughroutersAllnetworksareequalHOSTINTERNETROUTERPHYSICALNETUNIVERSITYOFTORONTOPhysicalNetworking•Packet-switching(connectionless)•Circuit-Switching(connectionoriented)•LANs:EthernetTokenRingFDDIATMUNIVERSITYOFTORONTOTheTCP/IPProtocolsTransmissionControlProtocol/

6、InternetProtocolOtherprotocolsinsuite:UDP,ARP,RARP,ICMP,IGMP,...APPLICATIONSERVICESRELIABLETRANSPORTSERVICECONNECTIONLESSPACKETDELIVERYSERVICEUNIVERSITYOFTORONTOIP:Connectionlesspacketdelivery•Datagramdelivery•Connectionless•Routing•Unreliable(best-effort)IPADDRESS:Hostshaveunique3

7、2-bitIPaddressesMultihomehostshaveoneaddresspernetworkconnectiondb.toronto.edu128.100.2.100hplabs.hp.com15.255.176.47math.tau.ac.il132.67.64.4cs.toronto.edu128.100.1.105,128.100.1.13,128.100.2.81,128.100.2.15UNIVERSITYOFTORONTOTCP:ReliableStreamTransport•Streamoriented•Virtualcircu

8、itconnectionbetweenports•E