Quality of Service (QoS): Managing Bandwidth More Effectively

Using QoS Classifiers To Configure QoS for Outbound Traffic

QoS VLAN-ID (VID) Priority

QoS Classifier Precedence: 5

The QoS VLAN-ID option supports up to 120 VLAN IDs (VIDs) as QoS classifiers, depending on rule use by other QoS options.

Where a particular VLAN-ID classifier has the highest precedence in the switch for traffic in that VLAN, then traffic received in that VLAN is marked with the VID classifier’s configured priority level. Different VLAN-ID classifiers can have differing priority levels.

Options for Assigning Priority. Priority control options for packets carrying a specified VLAN-ID include:

802.1p priority

DSCP policy (Assigning a new DSCP and an associated 802.1p priority; inbound packets must be IPv4.)

(For operation when other QoS classifiers apply to the same traffic, refer to “Classifiers for Prioritizing Outbound Packets” on page 6-9.)

N o t e

QoS with VID priority applies to static VLANs only, and applying QoS to

 

dynamic VLANs created by GVRP operation is not supported. A VLAN must

 

exist while a subject of a QoS configuration, and eliminating a VLAN from the

 

switch causes the switch to clear any QoS features configured for that VID.

 

 

Assigning a Priority Based on VLAN-ID

This option assigns a priority to all outbound packets having the specified VLAN-ID (VID). You can configure this option by either specifying the VLAN­ ID ahead of the qos command or moving to the VLAN context for the VLAN you want to configure for priority.

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