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Cisco ASR 901 Aggregation Services Router Command Reference Guide
OL-26031-07
Chapter 1 CLI Command Reference
police (percent)
In the above example, there is one policy map called parent_policy. In this policy map, a peak rate has
not been specified. The
bandwidth
command has been used, but this command does not represent the
maximum rate of bandwidth available. Therefore, the
police
(percent) command will look to the next
higher level (in this case serial interface 4/0) to get the bandwidth reference point. Assuming the
bandwidth of serial interface 4/0 is 1.5 Mbps, the
police
(percent) command will use 1.5 Mbps as the
basis for calculating the cir rate (1500000 * 30 percent).
How Bandwidth Is Calculated
The
police
(percent) command is often used in conjunction with the
bandwidth
and
priority
commands.
The
bandwidth
and
priority
commands can be used to calculate the total amount of bandwidth available
on an entity (for example, a physical interface). When the
bandwidth
and
priority
commands calculate
the total amount of bandwidth available on an entity, the following guidelines are invoked:
•
If the entity is a physical interface, the total bandwidth is the bandwidth on the physical interface.
•
If the entity is a shaped ATM permanent virtual circuit (PVC), the total bandwidth is calculated as
follows:
–
For a variable bit rate (VBR) virtual circuit (VC), the sustained cell rate (SCR) is used in the
calculation.
–
For an available bit rate (ABR) VC, the minimum cell rate (MCR) is used in the calculation.
For more information on bandwidth allocation, refer to the “Congestion Management Overview” chapter
in the
Cisco IOS Quality of Service Solutions Configuration Guide
.
Examples
The following example shows how to configure traffic policing using a CIR and a PIR on the basis of a
percentage of bandwidth. In this example, a CIR of 20 percent and a PIR of 40 percent have been
specified. Additionally, an optional bc value and be value (300 ms and 400 ms, respectively) have been
specified.
Router>
enable
Router#
configure terminal
Router(config)#
policy-map policy1
Router(config-pmap)#
class class1
Router(config-pmap-c)#
police cir percent 20 bc 300 ms be 400 ms pir percent 40
Router(config-pmap-c-police)#
exit
After the policy map and class maps are configured, the policy map is attached to an interface as shown
in the following example:
Router>
enable
Router#
configure terminal
Router(config)#
interface gigabitethernet0/1
Router(config-if)#
service-policy input policy1
Router(config-if)#
exit
Related Commands
Command
Description
bandwidth
(policy-map class)
Specifies or modifies the bandwidth allocated for a class belonging to a
policy map.
bridge-domain
Enables RFC 1483 ATM bridging or RFC 1490 Frame Relay bridging to
map a bridged VLAN to an ATM PVC or Frame Relay DLCI.
policy-map
Creates or modifies a policy map that can be attached to one or more
interfaces to specify a service policy.