A policy class that applies a set of classifiers to interfaces specifying, for each association, the precedence order of the classifier with respect to other classifiers applied to the same interface and, for each policy, the action to take for a packet that matches the classifiers referenced by the policy. Interfaces are specified abstractly in terms of interface groups or roles. This class may reference individual classifiers or blocks of classifiers. Classification data is identified by its type (i.e., single classifier or group of classifiers) and an identifier based on the type. A policy is formed by associating the classification data with an interface group, actions to be carried out based on classification and metering criteria, if applicable.