Quality of Service (QoS): Managing Bandwidth More Effectively

Using QoS Classifiers To Configure QoS for Outbound Traffic

Figure 6-23. Configuring and Displaying QoS Priorities on VLANs

If you then decided to remove VLAN_20 from QoS prioritization.

In this instance, No- override indicates that VLAN 20 is not prioritized by QoS.

Figure 6-24. Returning a QoS-Prioritized VLAN to “No-override” Status

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

This option assigns a previously configured DSCP policy (codepoint and 802.1p priority) to outbound IP packets having the specified VLAN-ID (VID). That is, the switch:

1.Selects an incoming IP packet on the basis of the VLAN-ID it carries.

2.Overwrites the packet’s DSCP with the DSCP configured in the switch for such packets.

3.Assigns the 802.1p priority configured in the switch for the new DSCP. (Refer to “Differentiated Services Codepoint (DSCP) Mapping” on page 6-58.)

4.Forwards the packet through the appropriate outbound port queue.

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