Reference Guide

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 107. Packet Drop Rate for WRED
You can create a custom WRED profile or use one of the five pre-defined profiles.
Table 61. Pre-Defined WRED Profiles (S4820T)
Default Profile Name Minimum Threshold Maximum Threshold Maximum Drop Rate
wred_drop 0 0 100
wred_teng_y 467 4671 100
wred_teng_g 467 4671 50
wred_fortyg_y 467 4671 50
wred_fortyg_g 467 4671 25
Quality of Service (QoS)
769