Cisco ASR 901 Command Reference Manual page 106

police (percent)
Usage Guidelines This command calculates the cir and pir on the basis of a percentage of the maximum amount of
bandwidth available on the interface. When a policy map is attached to the interface, the equivalent cir
and pir values in bits per second (bps) are calculated on the basis of the interface bandwidth and the
percent value entered with this command. The show policy-map interface command can then be used
to verify the bps rate calculated.
The calculated cir and pir bps rates must be in the range of 8000 and 2000000000 bps. If the rates are
outside this range, the associated policy map cannot be attached to the interface. If the interface
bandwidth changes (for example, more is added), the bps values of the cir and the pir are recalculated
on the basis of the revised amount of bandwidth. If the cir and pir percentages are changed after the
policy map is attached to the interface, the bps values of the cir and pir are recalculated.
Conform Burst and Peak Burst Sizes in Milliseconds
This command also allows you to specify the values for the conform burst size and the peak burst size
in milliseconds. If you want bandwidth to be calculated as a percentage, the conform burst size and the
peak burst size must be specified in milliseconds (ms).
Hierarchical Policy Maps
Policy maps can be configured in two-level (nested) hierarchies; a top (or "parent") level and a secondary
(or "child") level. The police (percent) command can be configured for use in either a parent or child
policy map.
Bandwidth and Hierarchical Policy Maps
The police (percent) command uses the maximum rate of bandwidth available as the reference point for
calculating the bandwidth percentage. When the police (percent) command is configured in a child
policy map, the police (percent) command uses the bandwidth amount specified in the next higher-level
policy (in this case, the parent policy map). If the parent policy map does not specify the maximum
bandwidth rate available, the police (percent) command uses the maximum bandwidth rate available on
the next higher level (in this case, the physical interface, the highest point in the hierarchy) as the
reference point. The police (percent) command always looks to the next higher level for the bandwidth
reference point. The following sample configuration illustrates this point:
Policymap parent_policy
class parent
shape average 512000
service-policy child_policy
Policymap child_policy
class normal_type
police cir percent 30
In this sample configuration, there are two hierarchical policies: one called parent_policy and one called
child_policy. In the policy map called child_policy, the police command has been configured in the class
called normal_type. In this class, the percentage specified by for the police (percent) command is
30 percent. The command will use 512 kbps, the peak rate, as the bandwidth reference point for class
parent in the parent_policy. The police (percent) command will use 512 kbps as the basis for calculating
the cir rate (512 kbps * 30 percent).
interface serial 4/0
service-policy output parent_policy
Policymap parent_policy
class parent
bandwidth 512
service-policy child_policy
Cisco ASR 901 Aggregation Services Router Command Reference Guide
1-92
Chapter 1 CLI Command Reference
OL-26031-07