ConfiguringQualityofService
D-Link UnifiedAccessPointAdministrator’sGuide
November2011 Page104
UnifiedAccessPointAdministrator’sGuide
cwMin
(MinimumContention
Window)
Thisparameterisinputtothealgorithmthatdeterminestheinitialrandombackoff
waittime(window)forretryofatransmission.
ThevaluespecifiedforMinimumContentionWindowistheupperlimit(in
milliseconds)ofarangefromwhichtheinitialrandombackoffwaittimeis
determined.
The
firstrandomnumbergenerate dwillbeanumberbetween0andthenumber
specifiedhere.
Ifthefirstrandombackoffwaittimeexpiresbeforethedat a frameissent,aretry
counterisincrementedandtherandombackoffvalue(window)isdoubled.
Doublingwill continueuntilthesizeoftherandom
backoffvaluereachesthe
numberdefinedintheMaximumContentionWindow.
ValidvaluesforcwMinare1,3,7,15,31,63,127,255,511,or1024.Thevaluefor
cwMinmustbelowerthanthevalueforcwMax.
cwMax
(MaximumContention
Window)
ThevaluespecifiedfortheMaximumCon tentionWindow
istheupperlimit(in
milliseconds)forthedoublingoftherandombackoffvalue.Thisdoublingcontinues
untileitherthedataframeissentortheMaximumContentionWindowsizeis
reached.
OncetheMaximumContentionWindowsizeisreached,retrieswillcontinueuntila
maximumnumberofretriesallowedis
reached.
ValidvaluesforcwMaxare1,3,7,15,31,63,127,255,511,or1024.Thevaluefor
cwMaxmustbehigherthanthevalueforcwMin.
Max.BurstLength TheMax.BurstLengthisanAPEDCAparameterandonlyappliestotrafficflowing
fromtheAPtothe
clientstation.
Thisvaluespecifies(inmilliseconds)themaximumburstlengthallowedforpacket
burstsonthewirelessnetwork.Apacketburstisacollectionofmultipleframes
transmittedwithoutheaderinformation.Thedecreasedoverheadresultsinhigher
throughputandbetterperformance.
Validvaluesformaximumburstlengthare0.0through999.
Wi-Fi Multimedia Settings
Wi‐FiMultiMedia Wi‐FiMultiMedia(WMM)isenabledbydefault.WithWMMenabled,QoS
prioritizationandcoordinationofwirelessmediumaccessison.WithWMM
enabled,QoSsettingsontheUAPcontroldownstreamtrafficflowingfromtheAPto
clientstation(APEDCAparameters)andtheupstreamtrafficflowingfrom
the
stationtotheAP(stationEDCAparameters).
DisablingWMMdeactivatesQoScontrolofstationEDCAparametersonupstream
trafficflowingfromthestationtotheAP.
WithWMMdisabled,youcanstillsetsomeparametersonthedownstreamtraffic
flowingfromtheAPtotheclientstation(APEDCAparameters).
To
disableWMMextensions,clickDisabled.
ToenableWMMextensions,clickEnabled.
Table40:QoSSettings(Cont.)
Field Description