To calculate the number of QoS resources used by a port-based access ingress QoS policy, the user must determine the number of FCs to use.
Only the FCs used by the match criteria classification entries configured in the dot1p and DSCP classification policies, which are referred to as ‟FCs in use,” are considered to calculate the number of FCs.
Default unicast meter 1 and default mulitpoint meter 9, which are created by default when a new policy is created, cannot be deleted. Unless the user explicitly configures another unicast meter or multicast meter for the FCs, the default unicast meter 1 is used for all unicast traffic and default mulitpoint meter 9 is used for all multipoint traffic (that is, broadcast, multicast, and unknown-unicast).
Use the following rules to compute the number of classification entries per FC in use:
If an FC is in use and is created without explicit meters, use default meter 1 for unicast traffic and default meter 9 for all other traffic (that is, broadcast, multicast, and unknown-unicast). The FC requires two classification entries in the hardware.
If an FC is in use and is created with an explicit unicast meter, use the unicast meter for unicast traffic and default meter 9 for all other traffic. The FC requires two classification entries in the hardware.
If an FC is in use and is created with an explicit unicast meter and an explicit multicast meter, use the unicast meter for unicast traffic and the multicast meter for all other traffic. The FC requires two classification entries in the hardware.
Two classification entries are used for the default fc-name configured using the config qos access-ingress default-fc command. The entries for the default FC are in addition to the FCs configured in the dot1p and DSCP classification policies.
Using the number of match criteria and FCs in use, calculate the total number of classification entries per policy with the following formula.
where:
TC is the total number of classification entries per policy
E(i) is the number of match criteria entries that classify packets to FCi. E(i) is one (1) if there is a dot1p or DSCP classification entry that classifies packets to FCi; itherwise, E(i) is zero.
the number is multiplied by two for the number of classification entries that FCi requires
another two entries are added for the default FC