Administrator Guide

space for other types. You can apply a WRED profile to a policy-map so that specified traffic can be prevented from consuming too much
of the BTM resources.
WRED uses a profile to specify minimum and maximum threshold values. The minimum threshold is the allotted buffer space for specified
traffic, for example, 1000KB on egress. If the 1000KB is consumed, packets are dropped randomly at an exponential rate until the
maximum threshold is reached (as shown in the following illustration); this procedure is the “early detection” part of WRED. If the
maximum threshold, for example, 2000KB, is reached, all incoming packets are dropped until the buffer space consumes less than 2000KB
of the specified traffic.
Figure 116. Packet Drop Rate for WRED
You can create a custom WRED profile or use one of the five pre-defined profiles.
Enabling and Disabling WRED Globally
By default, WRED is enabled on the system. You can disable or reenable WRED manually using a single command. Follow these steps to
disable or enable WRED in Dell EMC Networking OS.
• Enable WRED
CONFIGURATION mode
wred enable
• Disable WRED
CONFIGURATION mode
no wred enable
NOTE:
If you disable WRED globally, the system accepts any WRED profile you apply to traffic. But the changes do not
take effect until you enable WRED globally.
Creating WRED Profiles
To create WRED profiles, use the following commands.
1. Create a WRED profile.
CONFIGURATION mode
wred-profile
2. Specify the minimum and maximum threshold values.
WRED mode
threshold
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Quality of Service (QoS)