D-Link DSL-520B

50D-Link DSL-520B ADSL2+ Modem User Manual
Section 9 - Advanced Setup
Quality of Service
Manycommunicationandmultimediaapplicationsrequirelarge,high-speedbandwidthstotransferdatabetweenthelocalnetworkandtheinternet.
However,formanyapplicationsthereisoftenonlyoneinternetconnectionavailablewithlimitedcapacity.QoSdividesthiscapacitybetweenthe
dierentapplicationsandprovidesundelayed,continuousdatatransferinsituationswheredatapacketswithhigherpriorityaregivenpreference.
Click Quality of Serviceandthefollowingpagewillappear.UnderQualityofService,therearetwonetworksharemodes:QueueCongandQoS
Classication.
NetworkQoSisanindustry-widesetofstandardsandmechanismsforensuringhigh-qualityperformanceforcriticalapplications.ByusingQoS
mechanisms,networkadministratorscanuseexistingresourcesecientlyandensuretherequiredlevelofservicewithoutreactivelyexpanding
or over-provisioning their networks.
Traditionally,theconceptofqualityinnetworksmeantthatallnetworktracwastreatedequally.Theresultwasthatallnetworktracreceived
thenetwork’sbesteort,withnoguaranteesforreliability,delay,variationindelay,orotherperformancecharacteristics.Withbest-eortdelivery
service,however,asinglebandwidth-intensiveapplicationcanresultinpoororunacceptableperformanceforallapplications.TheQoSconcept
ofqualityisoneinwhichtherequirementsofsomeapplicationsandusersaremorecriticalthanothers,whichmeansthatsometracneeds
preferential treatment.