Quality of Service (QoS): Managing Bandwidth More Effectively

Using QoS Classifiers To Configure Quality of Service for Outbound Traffic

configure an 802.1p priority of 7 for packets received with a DSCP of 000110, and then enable diff-services:

Executing this command displays the current ToS configuration and shows that the selected DSCP is not currently in use.

The 000110 codepoint is unused, and thus available for directly assigning an 802.1p priority without changing the packet’s DSCP.

Note: All codepoints without a “DSCP Policy” entry are available for direct 802.1p priority assignment.

Figure 15-13. Example Showing Codepoints Available for Direct 802.1p PriorityAssignments

Notice that codepoints 000000 and 001001 are named as DSCP policies by other codepoints (000001 and 000110 respectively). This means they are not available for changing to a different 802.1p priority.

Outbound IP packets with a DSCP of 000110 will have a priority of 7.

Figure 15-14. Example of a Type-of-Service Configuration Enabling Both Direct 802.1p Priority Assignment and DSCP Policy Assignment

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