642 Dell PowerConnect 55xx Systems User GuideThis is the default QoS mode.• Advanced Mode — Per-flow Quality of Service (QoS).In Advanced mode, a per-flow QoS consists of a class map and a policer:– A class map defines the kind of traffic in a flow, and contains one ormore ACLs. Packets that match the ACLs belong to the flow.– A policer applies the configured QoS to a flow. The QoS configurationof a flow may consist of the egress queue, the DSCP or CoS value, andactions on out-of-profile (excess) traffic.• Disable Mode (QoS is not enabled)In this mode, all traffic is mapped to a single best-effort queue, so that notype of traffic is prioritized over another.Only a single mode can be active at a time. When the system is configured towork in QoS Advanced mode, settings for QoS Basic mode are not active andvice versa.When the QoS mode is changed, the following occurs:• When changing from Advanced mode to any other mode, policy profiledefinitions and class maps are deleted. ACLs, which are bonded directly tointerfaces, remain bonded.• When changing from Basic mode to Advanced mode, the QoS Trust modeconfiguration in Basic mode is not retained.• When disabling QoS, the shaper and queue setting (WRR/SP bandwidthsettings) are reset to default values.All other user configurations remain intact.
