7 Configuring Traffic Management414 Voyager Reference GuideConfiguring Queue ClassesQueue Class DescriptionQueue classes (QCs) are used to instantiate a framework, or template, foroutput queue schedulers. Like Access Control Lists (ACLs) they are createdand configured and then associated with an interface.There are a maximum of 8 priority-level queues for a QC. You can configurethe size (in packets) of each queue level as well as the queue specifier. Thequeue specifier is a tag assigned by the classifier and is used as a key to lookup the proper queue level. Three queue levels are pre-defined: theInternetwork Control (IC), Expedited Forwarding (EF), and Best Effort (BE)queues. The remaining queues can be assigned any name and QueueSpec youwant. The table below shows the values that correspond to these queue values:When you configure an ACL rule to use the priority action, you mustconfigure an Aggregation Class (AGC). This AGC will function as a policer,that is, non-conforming traffic will be dropped. You should configure theAGCs so that the aggregate of the NC and EF flows consumes no more than50% of the output link bandwidth. This action prevents lower-priority trafficfrom being starved. See RFC 2598 for more information. The other policersshould also be configured to prevent the lower-priority queue from beingstarved.Name of QueueLevel PriorityIETF DiffServCodepointQueue SpecifierValueInternetworkControl0 0xc0 7ExpeditedForwarding1 0xb8 6Best Effort 7 0 0
