The
main difference between RED and WRED is that WRED deals with different
colored packets. The router assigns a color to each packet. Committed
means green, conformed means yellow, and exceeded means red.
Each line module supports a default drop profile
and 15 configurable drop profiles.
WRED is not supported on the ES2 10G Uplink LM.
On the ES2 10G LM, you must configure WRED in one of the 15 configurable
drop profiles; you cannot configure its default drop profile.
To configure WRED:
Create a drop profile and enter Drop Profile Configuration
mode.
host1(config)#drop-profile internetDropProfile
host1(config-drop-profile)#
You can configure up to 16 drop profiles.
Set the average-length exponent, which specifies the exponent
used to weight the average queue length over time, controlling WRED
responsiveness.
Specifying an average-length exponent enables the RED
average queue length computation.
A higher value smooths out the average and slows WRED
reaction to congestion and decongestion, accommodating short bursts
without dropping. Too large a value can smooth the average to the
point that WRED does not react at all.
A lower value speeds up WRED reaction. Too low a value
can cause overreaction to short bursts, dropping packets unnecessarily.
(Optional) Set the minimum and maximum threshold for committed
traffic.
The thresholds specify a linear relationship
between average queue length and drop probability.
You can express thresholds as either percentages
of maximum queue size by including the keyword percent, or as absolute byte values by omitting the keyword.
