Cisco CRS Command Reference Manual page 113

Quality of Service Commands on the Cisco IOS XR Software
high-precedence traffic at congestion points. WRED ensures that high-precedence traffic has lower loss rates
than other traffic during times of congestion.
The mapping from keywords such as 0 (routine) and 1 (priority) to a precedence value is useful only in some
instances. That is, the use of the precedence bit is evolving. You can define the meaning of a precedence value
by enabling other features that use the value. In the case of high-end Internet QoS, IP precedences can be used
to establish classes of service that do not necessarily correspond numerically to better or worse handling in
the network.
Task ID
Task ID
qos
Examples
The following example shows how to set the IP precedence to 5 (critical) for packets that match the access
control list named customer1:
RP/0/RP0/CPU0:router(config)# class-map class1
RP/0/RP0/CPU0:router(config-cmap)# match access-group ipv4 customer1
RP/0/RP0/CPU0:router(config-cmap)# exit
RP/0/RP0/CPU0:router(config)# policy-map policy1
RP/0/RP0/CPU0:router(config-pmap)# class class1
RP/0/RP0/CPU0:router(config-pmap-c)# set precedence 5
RP/0/RP0/CPU0:router(config-pmap-c)# exit
RP/0/RP0/CPU0:router(config-pmap)# exit
RP/0/RP0/CPU0:router(config)# interface gigabitethernet 0/1/0/9
RP/0/RP0/CPU0:router(config-if)# service-policy output policy1
Related Commands
Command
class-map, on page 12
policy-map, on page 67
service-policy (interface), on page 93
OL-23235-03
Description
Defines a traffic class and the associated rules that match packets to
the class.
Creates or modifies a policy map that can be attached to one or more
interfaces to specify a service policy.
Attaches a policy map to an input interface or output interface to be
used as the service policy for that interface.
Cisco IOS XR Modular Quality of Service Command Reference for the Cisco CRS Router, Release 4.0
Operations
read, write
set precedence
107