1 QoS Overview ············································································································································1-1

Introduction ·············································································································································1-1

Traditional Packet Forwarding Service ···································································································1-1

New Requirements from Emerging Services ··························································································1-1

Congestion: Causes, Impacts, and Countermeasures ···········································································1-2

Causes ············································································································································1-2

Impacts ············································································································································1-2

Countermeasures ····························································································································1-2

Major Traffic Management Techniques ··································································································1-3

2 QoS Policy Configuration ·························································································································2-1

Overview ·················································································································································2-1

Configuring a QoS Policy························································································································2-1

Defining a Class ······························································································································2-1

Defining a Traffic Behavior ··············································································································2-4

Defining a Policy······························································································································2-5

Applying a Policy ·····························································································································2-6

Displaying and Maintaining QoS Policies ·······························································································2-8

3 Priority Mapping ········································································································································3-1

Priority Overview ·····································································································································3-1

Priority Mapping Overview ······················································································································3-4

Configuring a Priority Mapping Table······································································································3-6

Configuration Prerequisites ·············································································································3-6

Configuration Procedure··················································································································3-6

Configuration Example ····················································································································3-7

Configuring the Port Priority····················································································································3-7

Configuration Prerequisites ·············································································································3-8

Configuration Procedure··················································································································3-8

Configuration Example ····················································································································3-8

Configuring Port Priority Trust Mode·······································································································3-8

Configuration Procedure··················································································································3-9

Configuration Example ····················································································································3-9

Displaying and Maintaining Priority Mapping ··························································································3-9

4 Traffic Policing, Traffic Shaping,and Line Rate Configuration·····························································4-1

Traffic Policing, Traffic Shaping, and Line Rate Overview······································································4-1

Traffic Evaluation and the Token Bucket·························································································4-1

Traffic Policing ·································································································································4-2

Line Rate ·········································································································································4-3

CAR/GTS/Line Rate Configuration ·········································································································4-4

Configuring GTS······························································································································4-4

Line Rate Configuration Procedure ·································································································4-5

Displaying Line Rate ·······························································································································4-6

Table of Contents