D-Link DSL-520B - Page 57

57D-Link DSL-520B ADSL2+ Modem User Manual
Section 9 - Advanced Setup
QoS-DSCP Setting
InordertounderstandDierentiatedServicesCodePoint(DSCP),youshouldbefamiliarwiththedierentiatedservicesmodel(Diserv).
DiservisaClassofService(CoS)modelthatenhancesbest-eortInternetservicesbydierentiatingindividualusertrac,servicerequirements
andothercriteria.Packetsarespecicallymarked,allowingnetworknodestoprovidedierentlevelsofserviceviapriorityqueuingorbandwidth
allocation,orbychoosingdedicatedroutesfor
specictracows.
Asdisplayedinfollowingdiagram,theIPV4packethasaTOSeld.DiservdenesTOSeldinIPpacketheaders
referredtoasDSCP.HostsorroutesthatpasstractoaDiserv-enablednetworktypicallymarkeachtransmitted
packet with an appropriate DSCP. The DSCP markings are used by Diserv network routers to appropriately
classifypacketsandtoapplyparticularqueuehandingorschedulingbehavior.