3-2
Cisco 10000 Series Router Quality of Service Configuration Guide
OL-7433-09
Chapter 3 Configuring QoS Policy Actions and Rules
QoS Policies
Feature History for QoS Policies
Defining QoS Actions Using a Policy Map
A policy map associates a traffic class with one or more QoS actions. When configuring a policy map,
you specify the name of a class map and configure the actions you want the router to take on the matching
traffic. Before you can create class policies in a policy map, the class must have classification criteria
configured in a class map. The router supports QoS actions such as marking, policing, and bandwidth
distribution.
A single policy map can be attached to multiple interfaces concurrently. If you attempt to attach a policy
map to an interface when the sum of the bandwidth assigned to classes is greater than 99 percent of the
available bandwidth, the router logs a warning message and does not allocate the requested bandwidth
to all of the classes. If the policy map is already attached to other interfaces, it is removed from them.
Whenever you modify a class policy in an attached policy map, class-based weighted fair queuing
(CBWFQ) is notified and the new classes are installed as part of the policy map in the CBWFQ system.
System Limits for Policy Maps
Table 3-1
lists the system limits for policy maps supported on the Cisco 10000 series router.
Cisco IOS Release
Description
Required PRE
Release 12.0(17)SL
The policy map feature was introduced on the router.
PRE1
Release 12.2(15)BX
This feature was introduced on the PRE2.
PRE2
Release 12.2(28)SB
This feature was integrated in Cisco IOS Release 12.2(28)SB
for the PRE2.
PRE2
Release 12.2(31)SB
This feature was introduced on the PRE3.
PRE2, PRE3
Release 12.2(33)SB
This feature was enhanced to support 8192 policy maps per
system and implemented on the PRE3 and PRE4.
PRE3, PRE4
Table 3-1
System Limits for Policy Maps
Cisco IOS Release
Processor
Policy Maps per System
1
(up to this amount)
No. Classes per
Policy Map
2
All Releases prior to
Release 12.0(17)SL
PRE1
256
16
Release 12.0(17)SL
and later releases
PRE1
256
256
Release 12.0(25)SX
and later releases
PRE1
4096
32
Release 12.2(15)BX
and later releases
PRE2
256
64
Release 12.3(7)XI
and later releases
PRE2
4096
127
