Introduction
Thenetworkmanagementcentermanagestheentirepacketswitchingnetworktoensuretheeffectiveandcontinuousoperationofthenetwork.ItiscalledNMCforshort,alsocalledNetworkControlCenter(NCC).Thenetworkmanagementcenteritselfisusuallycomposedoftwoormoresmallcomputers,andonemainnumberisreservedtoensurethesecurityofnetworkmanagement.
NMChastwomanagementmethods:centralizedandcentralizedanddistributed.Theformerissuitableforsmallnetworksandprivatenetworks,andthelatterissuitablefornationalpublicbackbonenetworksandlargeprivatenetworks.Accordingtoitsfunctions,NMC'smanagementmethodscanbedividedintotwotypes:networkmonitoringmanagementandbillingmanagement,whichcanbeundertakenbydifferentnetworkmanagementcomputers.Asaspecialuser,thenetworkmanagementcomputerusesapermanentvirtualcircuitconnectionwithvariousdevicesontheInternettoperformnetworkmanagementfunctions.
Composition
Thenetworkmanagementcenteriscomposedofthreeparts:networkmanagementhost,networkmanagementterminalequipmentandperipheralequipment.Thenetworkmanagementhostusuallydevelopssoftwareonageneral-purposeminicomputertoformacomputersystemwithexactlythesamefunction,onemasterandonebackup(hotstandby)toensurethenormaloperationoftheentirenetwork;networkmanagementterminalequipmentincludesnetworkoperatorterminals(includingremoteterminals)),networkstatusdisplayandnetworkwide-lineprinter;peripheraldevicesmainlyincludedisks,tapes,etc.
Function
Thereareautomaticmanagementfunctionsandmanualmanagementfunctions.Automaticmanagementfunctionsincludenetworkmonitoring,faultdetectionandalarmreporting,networkutilizationandloadparametermeasurement,andcollectionofbillinginformation;manualmanagementfunctionsmainlyrefertooperatorswhomanageterminalequipment(includingremoteterminals)throughthenetworktocontroltheentirenetworkOrmanualmanagementandcontrolinlocalareas,mainlyincludingusermanagement,networksoftwaremanagement,softwareandhardwaremaintenancemanagement,andmeasurementandstatisticalinformationcollection.
①Theusermanagementcommunicationmanagementdepartmentprovidesuserswithmanagementservicesthroughthenetworkmanagementcenter,mainlyincludingtheaddition,deletion,andmodificationofuserlines,links,andcharacteristics;theuser'snetworkuseridentifier(NUI)Andnetworkuseraddress(NUA)settingsanduserselectionofbusinesssettingsandsoon.
②NetworkstartupInitializationofthenetworkmanagementcenter,packetswitchandconcentratoriscarriedoutindependentlybyeachdeviceorremotelyloadedbythenetworkmanagementcenter.Thedatafilesofthesamedatabasearestoredinthedisksofthenetworkmanagementcenterandthepacketswitchorconcentratoratthesametime.Thesedatafilesincludeinstructionsfornetworkusers,instructionsfornetworkdeviceconfiguration,andinstructionsforadjustingthesoftwaretothecurrentdemandstate.Duringnetworkoperation,thefilesinthenetworkmanagementcenter,packetswitchorconcentratormustbekeptconsistent.
③NetworkmonitoringandstatusdisplayAgroupoffunctionkeysenabletheoperatortounderstandthecurrentnetworkstatusandcontrolthenetwork.Networkmonitoringandstatusdisplayfunctionsincludenetworkconfigurationcontrol,networkalarmdetectionandreporting,andnetworkstatusdisplay.
④DatacollectionandstatisticsDailydatacollectionstartsautomaticallyafterthesystemisstarted.Itcancontinuouslyprovideoperatingdataoftheentirenetworkandacertainswitch.Thesedataincludeusercalls,communicationandreleaseofvirtualcircuits,switchandtrunkload,utilization,andservicequalitystatistics.Theabove-mentioneddailyoperationdatageneratesstatisticalinformationofthenetworkmanagementcenterandprintsitinaprescribedformat.
⑤ChargingmanagementSwitchesandconcentratorsshouldbeabletocollectallthecharginginformationandconvertthemintothechargingfilesofthenetworkmanagementcenter.Itsfunctionsincludecollectingcharginginformation,monitoringandstatusdisplayofcertainspecificusers,andtransmittingcharginginformationtousersattheendofacommunication.
⑥MaintenancemanagementSwitchesandconcentratorscanprovidelineandlinkmaintenancefunctions,includingsubscriberlinelooptesting,link-levelprotocolmonitoring,packet-levelmonitoring,linkservicequality,unitmodulemonitoring,etc.Whenthehardwareofthepacketswitchorconcentratorfails,thefailurecanbedetectedthroughtheautomaticfailuredetectionprogram.
Networkreliabilitymeasures
Thecoreofthepacketswitchingnetworkisthenetworkmanagementcenter.Inordertoensurethesafeandreliableoperationoftheentirenetwork,themeasuresthatneedtobetakenare:
①Theone-to-onehotstandbymodeisadoptedforthemainmodulesofthepacketswitchandthelarge-capacityconcentrator,andthenon-mainmodulescanadoptthen+1standbymode.
②Adual-relaycircuitisusedbetweenthepacketswitchestoworkatthesametime,andthedouble-relaycircuitismadetousecircuitswithdifferentgeographicalroutesordifferenttransmissionmedia.Adoublerelaycircuitcanalsobesetbetweenthepacketswitchandtheimportantconcentrator.
③Forcomputercentersorimportantusers,setupmorethan2usercircuitsandadoptmulti-linkprocedures.
④Thenetworkstructureadoptsadistributedstructure,withsufficientcircuitousroutes.Blockdetectionandcontroltechnologyisusedinthenetworktopreventdeadlock.