Disclaimer
The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.
Liability Disclaimer
In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.
Posting
Generally (W)RED is only suitable for rate adaptive traffic, and if the traffic is rate adaptive, you usually don't want to drop all such traffic's packets.
WRED can be used to create drop tiers for rate non-adaptive traffic.
On sub Ethernet bandwidth links, with few flows, I've found drop management better with FQ per flow queue depths.
RED works better with Ethernet or better bandwidths with many flows, especially when FQ not avaible.
Depending on platform, FRED or DBL might be more elegant options.
Much depends on your service requirements.