Cisco created Modular QoS CLI to help resolve problems with a multitude of QoS configuration commands becoming unorganized or standardized. MQC helps by defining a common set of configuration commands to configure many QoS features in a router or switch.
MQC categorizes classification, marking, and erlated actions into logical groupings in the command line interface. MQC tools all begin with the phrase ‘Class Based’ such as CB Weighted Fair Queue, CB Marking, CB, Policing, CB Shaping, and CB Header compression.
MQC seperates the classification function of a QoS tool from the action (PHB) that it wants to perform. MQC is seperated into three major commands, with several subordinate commands:
- Class-Map: command defineds the matching parameters for classifying packets into service classes
- Policy Map: PHB actions such as Marking, Queueing, and so on are configured under a Policy-map command
- Service Policy: a Policy Map is enabled on an interface by using the service-policy command.
Classifying packets requires the use of class maps to define your traffic.
Setting an action to your defined class-maps is done by referencing the class map within the policy map and setting an appropriate action.
The QoS Policy that’s been created which defines your traffic, and how you want to treat your traffic is enabled under an interface configuration using the service-policy commands and you can apply those commands on ingress or egress of an interface.