Administrator Guide
• If you do not configure Dell EMC Networking OS to honor DSCP values on ingress (refer to Honoring DSCP Values on Ingress
Packets), all traffic defaults to green drop precedence.
• Assign a WRED profile to either yellow or green traffic.
QOS-POLICY-OUT mode
wred
Displaying Default and Configured WRED Profiles
To display the default and configured WRED profiles, use the following command.
• Display default and configured WRED profiles and their threshold values.
EXEC mode
show qos wred-profile
Example of the show qos wred-profile Command.
Displaying WRED Drop Statistics
To display WRED drop statistics, use the following command.
• Display the number of packets Dell EMC Networking OS the WRED profile drops.
EXEC Privilege mode
show qos statistics wred-profile
DellEMC#show qos statistics wred-profile
Interface Te 1/1
Drop-statistic Dropped Pkts
Green 51623
Yellow 51300
Out of Profile 0
DellEMC#
Displaying egress–queue Statistics
To display the number of transmitted and dropped packets and their rate on the egress queues of an interface, use the following
command:
• Display the number of packets and number of bytes on the egress-queue profile.
EXEC Privilege mode
show qos statistics egress-queue
Pre-Calculating Available QoS CAM Space
Before Dell EMC Networking OS version 7.3.1, there was no way to measure the number of CAM entries a policy-map would consume
(the number of CAM entries that a rule uses is not predictable; from 1 to 16 entries might be used per rule depending upon its complexity).
Therefore, it was possible to apply to an interface a policy-map that requires more entries than are available. In this case, the system
writes as many entries as possible, and then generates an CAM-full error message (shown in the following example). The partial policy-
map configuration might cause unintentional system behavior.
%EX2YD:12 %DIFFSERV-2-DSA_QOS_CAM_INSTALL_FAILED: Not enough space in L3
Cam(PolicyQos) for class 2 (TeGi 12/20) entries on portpipe 1
The test cam-usage command allows you to verify that there are enough available CAM entries before applying a policy-map to an
interface so that you avoid exceeding the QoS CAM space and partial configurations. This command measures the size of the specified
policy-map and compares it to the available CAM space in a partition for a specified port-pipe.
Test the policy-map size against the CAM space for a specific port-pipe or all port-pipes using these commands:
• test cam-usage service-policy input policy-map {stack-unit } number port-set number
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Quality of Service (QoS)