22-20
ATM Switch Router Software Configuration Guide
OL-7396-01
Chapter 22
Configuring Quality of Service
Configuring IP QoS on Enhanced Gigabit Ethernet and Enhanced ATM Router Module Interfaces
The following commands show how to configure a service policy on an egress interface (output policy
map):
Example
Switch(config)#
policy-map out-policy
Switch(config-pmap)#
class prec2
Switch(config-pmap-c)#
bandwidth 10000
Switch(config-pmap-c)#
class prec4
Switch(config-pmap-c)#
bandwidth 100000
Switch(config-pmap-c)#
random-detect buffer-group 2 max-probability 1024 freeze-time 100
Switch(config-pmap-c)#
class prec6
Switch(config-pmap-c)#
bandwidth 100000
Switch(config-pmap)#
class class-default
Switch(config-pmap-c)#
bandwidth 10000
Note
Output policy maps:
•
Can have a maximum of 4 class maps, including the default class.
•
May be configured only on the physical interface.
•
The classifiers on the output direction must be Behavior Aggregate classifiers.
•
Must have exactly one class with ‘match any’ for default/unclassified traffic.
•
Must have bandwidth configured for every class.
•
‘queue-limit’ or ‘random-detect’ are mutually exclusive. ‘queue-limit’ is the default if
nothing is configured.
Command
Purpose
Step 1
Switch(config) #
policy-map
policy-name
Specifies the name of the service policy to configure.
Step 2
Switch(config-pmap) #
class
class-name
Specifies the name of a predefined class, which was defined with
the
class-map
command
Switch(config-pmap-c) #
class
class-default
Specifies the default class
Step 3
Switch(config-pmap-c) #
bandwidth
kbps
Specifies a minimum bandwidth (in Kbits/sec) guaranteed to a
traffic class. This must be specified for each class in the output
policy, including class-default.
Switch(config-pmap-c) #
random-detect
[
buffer-group
buffer-group-number |
max-probability
max-probability
|
freeze-time
millisecond
]
Enables the XPIF based Random Early Detect (xRED) drop
policy.
buffer-group-number
specifies one of 4 possible buffer groups
available (value 0 to 3)
max-probability
range is 1 to 65535, and
freeze-time
range is 10 to 2000 milliseconds.
Switch(config-pmap-c) #
queue-limit
buffer-group
buffer-group-number
Configures the Tail drop policy.
buffer-group-number
specifies one of 4 possible buffer groups
available (value 0 to 3)
