6

Quality of Service (QoS): Managing

Bandwidth More Effectively

Contents

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3

Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7

Classifiers for Prioritizing Outbound Packets . . . . . . . . . . . . . . . . . . . . 6-9

Packet Classifiers and Evaluation Order . . . . . . . . . . . . . . . . . . . . 6-9

Preparation for Configuring QoS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-13 Steps for Configuring QoS on the Switch . . . . . . . . . . . . . . . . . . . 6-13

Planning a QoS Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-15

Prioritizing and Monitoring QoS Configuration Options . . . . . . 6-15

Policy Enforcement Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-15

QoS Resource Usage and Monitoring . . . . . . . . . . . . . . . . . . . . . . 6-15

Planning and Monitoring Rule Usage . . . . . . . . . . . . . . . . . . . . . . 6-16

Managing QoS Resource Consumption . . . . . . . . . . . . . . . . . . . . . 6-16

Troubleshooting a Shortage of Rule Resources . . . . . . . . . . . . . . 6-17

Examples of QoS Resource Usage . . . . . . . . . . . . . . . . . . . . . . . . . 6-18

Using QoS Classifiers To Configure QoS for Outbound Traffic . . . . . . . . 6-20

Viewing the QoS Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-20

No Override . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-21

QoS UDP/TCP Priority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-21

Assigning 802.1p Priority Based on TCP or UDP Port Number . 6-22

Assigning a DSCP Policy Based on TCP or UDP Port Number . 6-24

QoS IP-Device Priority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-28

Assigning a Priority Based on IP Address . . . . . . . . . . . . . . . . . . . 6-29

Assigning a DSCP Policy Based on IP Address . . . . . . . . . . . . . . 6-30

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