Cisco ONS 15454 - Page 180

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Cisco ONS 15454 SONET/SDH ML-Series Multilayer Ethernet Card Software Feature and Configuration Guide, R4.0
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Chapter 13 Configuring Quality of Service
Configuring QoS
A policy map also has these characteristics:
• A policy map can contain multiple class statements, each with different match criteria and actions.
• A separate policy-map class can exist for each type of traffic received through an interface.
• Each packet will be matched to one and only one class map. If multiple matches are possible for a
packet, it will match the first class map entry which applies.
You can attach only one policy map per interface per direction.
Beginning in global configuration mode, follow these steps to create a policy map:
Command Purpose
Step 1
Router(config)# policy-map
policy-map-name
Creates a policy map by entering the policy map name, and enters
policy-map configuration mode. By default, no policy maps are
defined.
Step 2
Router(config-pmap)# class
class-map-name
Selects a traffic class to act on and enters policy-map class
configuration mode, which allows actions to be specific for the class.
By default, no class maps are selected.
Step 3
Router(config-pmap-c)# police
rate-bps burst-byte conform-action
[{set-cos-transmit
cos value |
transmit} exceed-action {drop |
set-cos-transmit
cos value }]
Defines a policer for the currently selected class when the policy map
is applied to input. Policing is supported only on ingress, not on egress.
• For rate-bps, specify the average traffic rate in bits per second
(bps). The range is 96000 to 8000000000.
• For burst-byte, specify the normal burst size in bytes. The range is
8000 to 64000.
• Conform action options are:
– Set a VLAN CoS priority value and transmit
– Transmit packet (default)
• Exceed action options are:
– Set a CoS value and transmit
– Drop packet default)
Step 4
Router(config-pmap-c)# bandwidth
{
8-2000000 | percent }
Specifies the minimum committed bandwidth for the currently selected
class. When the policy-map is applied to an output, an output queue
with the proper weight is created for this class. The bandwidth
command is supported only on egress, not on ingress. Valid choices are:
• Rate in kilobits per second (8 to 2000000)
• Percent of total available bandwidth (1 to 100)
If multiple classes and bandwidth actions are specified in a single
policy map, they must use the same choice in specifying bandwidth
(kilobits or percent).