Quality of Service (QoS): Managing Bandwidth More Effectively

Contents

QoS IP Type-of-Service (ToS) Policy and Priority . . . . . . . . . . . . . . . 6-34

Assigning an 802.1p Priority to IPv4 Packets on the Basis of the ToS

Precedence Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-35

Assigning an 802.1p Priority to IPv4 Packets on the Basis of Incoming

DSCP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-36

Assigning a DSCP Policy on the Basis of the DSCP in IPv4 Packets

Received from Upstream Devices . . . . . . . . . . . . . . . . . . . . . . . . . 6-40

Details of QoS IP Type-of-Service . . . . . . . . . . . . . . . . . . . . . . . . .6-43

QoS VLAN-ID (VID) Priority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-46

Assigning a Priority Based on VLAN-ID . . . . . . . . . . . . . . . . . . . .6-46

Assigning a DSCP Policy Based on VLAN-ID (VID) . . . . . . . . . . . 6-48

QoS Source-Port Priority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-52

Assigning a Priority Based on Source-Port . . . . . . . . . . . . . . . . . .6-52

Assigning a DSCP Policy Based on the Source-Port . . . . . . . . . .6-54

Steps for Creating a Policy Based on Source-Port Classifiers . . 6-54

Differentiated Services Codepoint (DSCP) Mapping . . . . . . . . . . . . . 6-58

Default Priority Settings for Selected Codepoints . . . . . . . . . . . . 6-59

Quickly Listing Non-Default Codepoint Settings . . . . . . . . . . . . . 6-60

Effect of “No-override” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-61

Note On Changing a Priority Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-62

Example of Changing the Priority Setting on a Policy When One or

More Classifiers Are Currently Using the Policy . . . . . . . . . . . . . 6-62

IP Multicast (IGMP) Interaction with QoS . . . . . . . . . . . . . . . . . . . . . . . . . 6-65

QoS Messages in the CLI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-65

QoS Operating Notes and Restrictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-66

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