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Дефиниция
Клас на услугата (CoS)мрежа е техниката на мрежата или методът, използван за предоставяне на качество на услугата (QOS). По-конкретно, CoS е метод за класифициране и приоритизиране на пакети с данни въз основа на типа приложение (глас, видео, имейл, прехвърляне на файлове, обработка на транзакции и т.н.), потребителски тип (VIОбикновен потребител) или другоcl методи за асификация и т.н."Първо- ниво" флагове за приоритет се присвояват на приложения за данни—като критични за мисията транзакции с данни или предаване на видео или глас—които се променят бързо, а флаговете с нисък приоритет се присвояват на чувствителен към време, по-малко чувствителен към време трафик, като електронна поща и уеб сърфиране.
Thedivisionofcommunicationqualitybasedontheprobabilityofacallbeingblockedordelayedformorethanacertaintime.Itisthecriterionofwhetheritisanincomingcallwhenitisbusy.
Свързани понятия
Calllossrate
Whenmultiplechannelsareshared,becausethenumberofusersisgreaterthanthenumberofchannels,itmayhappenthatmanyusersrequesttotalkatthesametimebutthenumberofchannelscannotIftherequirementsaremet,onlyapartoftheuserscanbeallowedtotalkatthistime,andtheotherpartoftheuserscannottalk,untilthereisafreechannel,andthenlettheuserswhoneedtotalk.Therefore,althoughsomeusersmadeacall,butfailedtocompletethecallbecausethereisnochannel,thisiscalledacallfailure,thatis,a"callloss"occurs.
Fromtheperspectiveofachannel,evenifitcommunicatesuninterruptedlywithinanhour,theamountoftrafficitcancompleteisonly1Ireland.Sinceusersinitiatecallsatrandom,itisimpossibletousethechanneluninterruptedly,sotheactualvolumeoftrafficthatcanbecompletedbyachannelmustbelessthan1Ireland.Thismeansthatchannelutilizationcannotreach100%.Inthecaseofsharedchannels,itisdifficultforthecommunicationnetworktoensurethatallcallsofeachuseraresuccessful,andasmallamountofcallfailureswillbecalled"callloss".
Calculation
Servicequalityisanexpectationthatcustomerscanexperiencewhenmakingaphonecall.Inaloss-basedsystem,thequalityofserviceisdescribedastheratiooflossduringbusyhours.Foraninvalidcallsystem,thequalityofservicecanbecalculatedusingFormula1.
Foradelayedcallsystem,thequalityofserviceismeasuredbythefollowingthreepoints:
·1)Средно забавяне-описва средното време, през което заявката на потребителя се забавя, докато чака връзка.
·2)Averagedelay-Describetheaveragetimetheuserspendswaitingforaconnectionregardlessofwhetherthecallisdelayedornot.
·3)Theprobabilitythatausermaybedelayedlongerthantimetwhilestillwaitingforconnection.Thetimetisselectedbythetelecommunicationserviceproviderinordertomeasurewhethertheirservicemeetsthelevel.
Application
Servicelevelisasignoftheservicequalityoftelecommunicationsenterprises,animportantbasisfortheresearchdepartmenttodeterminethegroupstructureofswitchingequipment,andanimportantindicatorforthedesigndepartmenttomeasurethequalityoftelecommunicationsnetworkdesign.Thedeterminedservicelevelishigh,whichwillcauseawasteoffunds;whilealowlevelwillreducethequalityoftelecommunicationsservices.
Differenttelecommunicationsapplicationsrequiredifferentqualityofservice.Forexample,ifatelecommunicationsserviceproviderdecidestoprovidedifferentqualitiesfordifferentvoiceconnections,thenahigh-qualityvoiceconnectionwillhaveabetterconnectionqualitythananormalvoiceconnection.Inthisway,differentusesdeterminedifferentservicequality.Tohelptelecommunicationsserviceprovidersmarkettheirdifferentservices,eachserviceisplacedintoaspecificcategory.Eachserviceleveldeterminestherequiredservicelevel.
Accordingtothesurveyandresearchonthesametelephoneinthecity,thetotalcalllossis2to5%.Howtoallocatethetotalcalllosstoeachselectionlevelrequiresatechnicalandeconomiccomparison.Generally,thesensitivepartoftheuserisallocatedwithasmallercallloss.Forexample,thecalllossofstep-by-stepsystemandcrossbarsystemissetat0.5%whentheuserpicksupthephoneandlistenstothedialtone.Theselect-leveloutgoinglineisconnectedtotheinterofficetrunkline,andthelineinvestmentisrelativelylarge.Generally,itisallocatedto1%.Thecalllossrateatalllevelsofmycountry'slong-distanceautomaticnetworkbackboneroutingissetat1%.