Dell PowerConnect 55xx Systems User Guide 681FILE LOCATION: C:\Users\gina\Desktop\Checkout_new\Maintenance Projects\DellContax\sources\CxUGQoS.fmD E L L C O N F I D E N T I A L – P R E L I M I N A R Y 1 0 / 3 0 / 1 3 - F O R P R O O F O N LYa Single Policer — Create a policy that associates a class map with asingle policer in the Policy Table pages and the Class Mapping pages.Within the policy, define the single policer.b Aggregate Policer — Create a QoS action for each flow. This actionsends all matching frames to the same policer (aggregate policer),defined in the Aggregate Policer pages. Create a policy that associatesa class map with the aggregate policer in the Policy Table pages.6 Bind the policy to an interface in the Policy Binding pages.DSCP MappingWhen a policer is assigned to a class map (flow), you can specify the action totake when the amount of traffic in the flow(s) exceeds the QoS-specifiedlimits. The portion of the traffic that causes the flow to exceed its QoS limitis referred to as out-of-profile packets.If the exceed action is Remark DSCP (as opposed to Drop), the switchrewrites the original DSCP value of the out-of-profile IP packets to a newvalue, based on the values entered in the DSCP Mapping page. The switchuses the new values to assign resources and egress queues to these packets.The switch physically replaces the original DSCP value in the out-of-profilepackets with the new DSCP value.To use the Remark DSCP exceed action, set the DSCP Out value in theDSCP Mapping page. Otherwise the action is null, because the DSCP valuein the packet is rewritten to the original DSCP value, set by factory default.
