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Table 60. Default DSCP to Queue Mapping (continued)
DSCP/CP hex range
(XXX)xxx
DSCP Definition Traditional IP
Precedence
Internal Queue ID DSCP/CP decimal
101XXX EF (Expedited
Forwarding)
CRITIC/ECP 2 32–47
100XXX AF4 (Assured
Forwarding)
Flash Override 2 32–47
011XXX AF3 Flash 1 16–31
010XXX AF2 Immediate 1 16–31
001XXX AF1 Priority 0 0–15
000XXX BE (Best Effort) Best Effort 0 0–15
● Enable the trust DSCP feature.
POLICY-MAP-IN mode
trust diffserv
Honoring dot1p Values on Ingress Packets
The Dell Networking OS honors dot1p values on ingress packets with the Trust dot1p feature.
The following table specifies the queue to which the classified traffic is sent based on the dot1p value.
Table 61. Default dot1p to Queue Mapping
dot1p Queue ID
0 0
1 0
2 0
3 1
4 2
5 3
6 3
7 3
The dot1p value is also honored for frames on the default VLAN. For more information, refer to Priority-Tagged Frames on the
Default VLAN.
● Enable the trust dot1p feature.
POLICY-MAP-IN mode
trust dot1p
Enabling Fall Back to Trust Diffserve or dot1p
When using QoS service policies with multiple class maps, you can configure the Dell Networking OS to use the incoming DSCP
or dot1p marking as a secondary option for packet queuing if no match occurs in the class maps.
When you use class-maps, traffic is matched against each class-map sequentially from first to last. The sequence is based on
the priority of the rules, as follows:
1. Rules with lowest priority, or in the absence of a priority configuration.
2. Rules of the next numerically higher queue.
By default, if no match occurs, the packet is queued to the default queue, Queue 0.
In the following configuration, packets are classified to queues using three class maps:
624
Quality of Service (QoS)