Setup Guide

space for other types. You can apply a WRED prole to a policy-map so that specied trac can be prevented from consuming too much
of the BTM resources.
WRED uses a prole to specify minimum and maximum threshold values. The minimum threshold is the allotted buer space for specied
trac, 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 buer space consumes less than 2000KB of the specied
trac.
Figure 111. Packet Drop Rate for WRED
You can create a custom WRED prole or use one of the ve pre-dened proles.
Creating WRED Proles
To create WRED proles, use the following commands.
1 Create a WRED prole.
CONFIGURATION mode
wred-profile
2 Specify the minimum and maximum threshold values.
WRED mode
threshold
Applying a WRED Prole to Trac
After you create a WRED prole, you must specify to which trac Dell EMC Networking OS should apply the prole.
Dell EMC Networking OS assigns a color (also called drop precedence) — red, yellow, or green — to each packet based on it DSCP value
before queuing it.
DSCP is a 6–bit eld. Dell EMC Networking uses the rst three bits (LSB) of this eld (DP) to determine the drop precedence.
Quality of Service (QoS)
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