Cisco ASR 9000 Series Service Configuration Guide

Configuring Hierarchical Modular QoS on Cisco ASR 9000 Series Routers
Contents
QC-124
Cisco ASR 9000 Series Aggregation Services Router Modular Quality of Service Configuration Guide
OL-23108-02
Contents
• Information About Hierarchical QoS, page 124
• How to Configure Hierarchical QoS, page 131
• Configuration Examples for Hierarchical QoS, page 143
• Verifying the Configuration of Hierarchical Policies, page 151
• Additional References, page 152
Information About Hierarchical QoS
Hierarchical QoS allows you to specify QoS behavior at multiple policy levels, which provides a high
degree of granularity in traffic management. A hierarchical policy is a QoS model that enables you to
specify QoS behavior at multiple levels of hierarchy. You can use hierarchical policies to:
• Allow a parent class to shape multiple queues in a child policy
• Apply specific policy map actions on the aggregate traffic
• Apply class-specific policy map actions
• Restrict the maximum bandwidth of a virtual circuit (VC) while allowing policing and marking of
traffic classes within the VC
The service-policy command is used to apply a policy to another policy, and a policy to an interface,
subinterface, VC, or VLAN.
For example, in a three-level hierarchical policy, use the service-policy command to apply:
• Bottom-level policy to a middle-level policy
• Middle-level policy to a top-level policy
• Top-level policy to an interface, subinterface, VC, or VLAN
Benefits of Hierarchical Policies
Depending on the type of hierarchical QoS policy you configure, you can:
• Shape multiple queues to a single rate
• Divide a single class of traffic into one or more subclasses
• Specify the maximum transmission rate of a set of traffic classes that are queued separately, which
is essential for virtual interfaces such as Frame Relay PVCs and IEEE 802.1Q virtual VLANs
• Configure minimum bandwidth queues on virtual circuits
• Shape the aggregate traffic of queues on a physical interface (for example, provide a 10-megabits
per second (Mbps) service on a 100-Mbps physical interface)
• Restrict the maximum bandwidth of a VC while allowing policing and marking of classes within the
VC

Cisco ASR 9000 Series Specifications

General

Series	ASR 9000
Category	Network Router
Modular Design	Yes
Redundancy	Yes (Hardware and Software)
Operating System	Cisco IOS XR
Interfaces/Ports	10G, 40G, 100G, 400G Ethernet
Expansion Slots	Varies by model
Routing Protocol	BGP, OSPF, IS-IS, EIGRP
Management	CLI, SNMP, NETCONF
Power Supply	Redundant
Port Density	Varies by model
Power Supply Options	AC, DC
Memory	Varies by model
Storage	Varies by model
Dimensions	Varies by model
Weight	Varies by model