Parameterized Filters Overview
Parameterized filters allow you to implement customized filters for each subscriber session. In parameterized filters, you use variables called unique identifiers (UIDs) to define your filter. When services are activated for a subscriber, actual values are substituted for the variables and are used to create filters.
Parameterized filters are configured under a dynamic profile. You can configure a general baseline filter under a dynamic profile and then provide specific variables of that filter when a dynamic session is activated. These variables can include policing rates, destination addresses, ports, and other items.
To provide better scaling, the system analyzes a dynamic profile, and then determines whether the set of variables for one session is the same as for a previous session. If a matching filter already exists, the session creates an interface-specific filter copy of that filter template. If the filter does not already exist, the session reads the configuration and compiles a new filter. This filter is installed as a template with an interface-specific filter copy for the current session pointing to it.