Definition
Dorsale Internet: rete dorsale Internet
Severalcomputersareconnected,andeachothercanseeotherpeople’sfiles.Thisiscalledalocalareanetwork,computersintheentirecityIftheyareallconnected,itisametropolitanareanetwork,andthenetworkthatconnectscitiesiscalledabackbonenetwork.ThesebackbonenetworksaretheInternetthatcanbedirectlyconnectedtoforeigncountriesapprovedbythestate.OtherISPs(InternetServiceProviders)withaccessfunctionshavetogothroughthesebackbonenetworksiftheywanttoconnectabroad.
Compositio
"Backbonenetwork"isoftenusedtodescribethelarge-scalenetworkstructure.Todescribethenetworkstructure,itismainlytolookatthenetworktopology,notthespecificuse.Thetransmissionmethodorprotocol.Thebackbonenetworkisgenerallyawideareanetwork:therangeofactionistenstothousandsofkilometers.
Thebackbonenetworkiscomposedofmultipletransmissionmethodsandmultipleprotocolcombinations.
mycountryhas9majorbackbonenetworks:
.ChinaPublicComputerInternet(CHINANET)
❷.ChinaGoldenBridgeInformationNetwork (CHINAGBN)
ChinaUnicomComputerInternet(uninet)
.ChinaNetcomPublicInternet(CNCNET)
.ChinaMobileInternet(CMNET)
❻.ChinaEducationandResearchNetwork (CERNET)
❼.ChinaScienceandTechnologyNetwork (CSTNET)
.ChinaGreatWallInternet(CGWNET)
ChinaInternationalEconomicandTradeInternet(CIETNET)
Progressus
Overview
Withtherapiddevelopmentofmoderntelecommunications,computerandInternettechnologies,data,voice,video,etc.Businesstransmissionsareconstantlyincreasingandareshowingatrendofconvergence.Theexistingnetworkhasbeenunabletomeettherapidlygrowingbusinessneeds.Thereisastrongneedtobuildanewtypeofbroadbandbackbonenetworktocarrytheserapidlydevelopingservices.
Physica "
SONET(SynchronousOpticalNetwork)hasimportantvalueinmanyaspects,makingitthemostimportantprotocolforlong-distance,high-speedopticalfibercommunication.Firstofall,SONET'sscalabilitymakesittheprimarytechnologytorealizeanewroundofhigh-speedports.BecauseOC-3(155Mbps)hasbecomeanoutdatedauxiliarytechnology,OC-48(2.4Gbps)portspeedshavebecomeverycommononhigh-speedroutersandswitches,andOC-768(40Gbps)portspeedswillsoondebut.Asthethroughputrateofdatatrafficcontinuestoincrease , SONEThasbecomeanimportantbackbonenetworktransmissiontechnology.ThebackbonenetworkusesalrgenumberofSFPhot-swappableopticalmodules.Theopticalmodulesuse high-speed and long-distancetosolve the upgrade and practicalapplicationproblems.
BeforetheemergenceofSONET,eachfiberopticequipmentmanufacturerworkedindependentlyanduseditsownindependenttechnologyinproductproduction,andtheproductswereincompatiblewitheachother.TheemergenceofSONEThasplayedaroleinstandardizinghigh-speedopticalfiberdatatransmission.
Datalinklayer
ATMcreatesasinglenetworkforvoice,videoanddata,andthevoiceandvideostreamscanbemaintainedatthelowlatencyandOnthejitterlevel.Atthesametime,time-insensitivedatacanmakefulluseoftheremainingchannelcapacity,whichcanrelativelyreducethecostofprovidingservicequalityassurance.
JustasSONEThasmanyfeaturesthatarenotincludedinthedefinitionoftraditionalphysicallayerprotocols,ATMcannotbecompletelyregardedasadatalinklayerprotocol.AlthoughanATMcellisverysimilartoatypicallayer2dataframe,haserrorcorrectioncapabilities,andalsocontainsaddressinformationthatisveryimportantforlocaldatalinks,thesecondlayerproceduresdonotrequirethesameasATM.Convertallcommunicationstreamsintofixed-lengthcells.
ATMhaselaborateservicequalityQoS,withoutthecompatibilityrequiredbythedatalinklayer.However,ATM,asaninterfacewiththephysicallayer,isundoubtedlyverysuitableforthedefinitionofthesecondlayerprotocol.ItsoptionsforthefirstlayerincludemanyopticalfibertransmissionmethodsfortransportingATMcells,includingSONET,Category5twistedpaircoppercables,andT1lines.
AlthoughATMcanalsobeusedasastatisticalmultiplexertoprovideservicesforalargenumberofnon-real-timedatastreams,itsmainadvantageliesintheabilitytoreceivereal-timedatastreams(suchasvoiceandvideo)andDoesnotcausejitteranddelay.
Networklayer
Atthenetworklayer,withthegreatsuccessoftheInternet,IPhasbecomearecognizedstandard.Withthedevelopmentoftechnologyandthediversificationofbearerservices,IP,aconnectionlessprotocolthattransmitsdataina"best-effort"manner,needstoprovideservicequalityassurance(QoS)forthebusiness,otherwiseitwillnotbeabletomeettherequirementsofthebackbonenetwork.Carrier-classservicequality.
Lookingatthenetworklevel
In hoc, atthenetwork gradu, theca- netis operis consistens physico, thedatalinklayer and the net-layer forms Thearchitecture of IP/ATM/SONET/Optical.Quamvis, SONET'sAPSequipmentum insanabile "culpam tolerantiae". Inordinata est operandi culpae ta- mentum, insolutionem.
TheshortcomingsoftheIP/ATM/SONET/Opticalarchitecturearegraduallyexposedwiththedeepeningoftheapplication:lowefficiency,complexequipment,highcost,complexmanagement,etc.AsthepacketforwardingspeedofgigabitroutingswitcheshasincreasedtoseveraltensofmegabytesandhasSONETportsof155Mbpsand622Mbps,theInternetbackbonenetworkisconstructedbyconnectingrouterswiththePPPprotocol.ThisisIPoverSONET(POS).structure.ThisstructuresoonreplacedATMasthemainstreamofInternetbackbonenetworktechnology.Itincreasedthetransmissionefficiencyfromlessthan80%tomorethan95%,andsimplifiedequipmentandreducedcosts.
IPoverSONETisnottheultimatesystemofhierarchicalsimplification.Inthebackbonenetwork,theSONETlayercanbefurthersimplified,andIPapplicationscanberundirectlyontheopticalchannel(IPoverOptical).Theall-opticalnetworkdoesnotrequirecomplicatedlinklayermanagementattheSONETlayer,andtheinherentdistributedsurvivalcharacteristicsoftheInternetmakeitcapableofprotectionandself-healing.SDHandATMarenotusedintheIP-optimizedopticalnetwork,andtheforwardingandswitchingofdatapacketsiscompletedbyagigabitroutingswitch.SincenolowerlayertransmissionprotocolcanbeusedintheIP-optimizedopticalnetwork,self-healingrecoveryisbestdoneatthenetworklayer.YoucanuseMPLS(Multi-ProtocolLabelSwitching)orDPT(DynamicPacketTransmission)torealizeself-healingrecoveryonthenetworklayertokeeptheentirenetworkrobustandefficient.
QualityofService
ThenewgenerationofbroadbandIPbackbonenetworkisnolongertheInternetinthetraditionalsense.Itneedstorunmoreservicesonitsbackbone.Thenewbackbonenetworkstructuremustbeabletoprovidemultipleservicesincludingvoice,data,andvideo.Therefore,acertainqualityofservice(QoS)isrequired.Thisqualityofservicereferstotherequirementtoobtainhigh-qualityguaranteesintermsoftimedelayandtransmissionerrorrate.Inthenetwork,itmustbeabletoprovidethemeansofserviceflowcontrolandthemethodofflowmanagement.
Forbroadbandbackbonenetworks,thepursuitofmaximizingtheuseofresources,reducingcosts,andimprovingefficiencyarethefundamentalrequirementsfornetworkconstructionandnetworkoperations.Therefore,itisnecessarytochooseefficientnetworkingtechnologyatthehighlevelofthenetworktogivefullplaytophysicalresources.Trafficmanagementtechnologycanensurethequalityofserviceofeachbusinessinacongestednetwork.
IETFestablishedanewworkinggroupfromtheintegratedserviceengineeringgrouptocreateadifferentiatedservice(DiffServ)toimplementtheQoSfunctioninthebackbonenetwork.AnothereffectivemechanismforprioritizingtrafficinanIPnetworkisTCPratecontrol,whichisachievedbyadjustingthesizeoftheterminalwindowinsteadoflettingitgrowarbitrarily.TCPratecontrolcanreducepackettrafficonthenetwork.
AnimportantissueinIPbackbonenetworkmanagementishowtomonitortrafficandpreventandresolvecongestion.InordertoadapttothedevelopmentofIPoverATM,themulti-protocollabelswitchingtechnologyMPLShasemerged.MPLScanestablishavirtualcircuitforIPreal-timeservicedataflowbasedonthelabelintheATMswitchtoensureQoS.
Thefuturebroadbandbackbonenetworkwilltakeonthetaskofunifyingthethreenetworksandprovideasupportingplatformformultipleservices.Thenetworkmustfirsthavehighefficiency,makethenetworklevelmoreconcise,andthusobtainhightransmissionefficiency;inaddition,itisnecessarytoworkonthenetworklayerorahigherapplicationleveltoimprovethequalityofservice,trafficmonitoringandnetworkmanagementfunctionstoAhigherrealm.
Relateddifferences
Firstofall,theconceptofbackbonenetworkexistsinmanynetworks,suchasCPmetropolitanareanetwork,IPbearernetwork,etc.Theso-calledbackbonenetworkislocatedintheupperlayerofthenetworkstructure.Anetworkformedbytheconnectionofcorenetworkelementdevices.Secondly,inresponsetothisquestion,Iguesswhatthehostwantstoaskistherelationshipbetweenthecorenetworkandthebackbonenetworkofthebearernetwork.Eachprefecturecity(prefecturecity:city-levelcity)basicallyhasitsownlocalcorenetworkswitchroom,whichcompleteslocalandforeigncalltransferanddatatransmission.Ifyouwanttoexchangebusinesswithotherplaces,youneedtorelyonareliabletransmissionnetworktocompletethistask.Therefore,thisreliablenetworkprovidesan"interface"(actuallyadevice),andwecanintegratethecorenetworkThenetworkelementequipmentattheborderisconnectedtothe"interface"ofthereliabletransmissionnetwork,andthisinterfaceentersthebackbonenetworktocompletethetransmissiontaskwhenitgoesup.Simplyput,thebearernetworkistheStateGrid,andthecorenetworkisthenetworkofeachpowerstation.Tocompletetheoverallplanningofeachpowerstation,itmustbeconnectedtotheStateGrid.