Backbone Diffserv Configuration (3): WRED Tuning
Min threshold value should be high enough to maximize the link utilization
If too low, packets may be dropped unnecessarily, and the link will not be fully used
Min threshold = 0.1 * P
where P is the pipesize = RTT * BW / (MTU * 8)
we suggest that you use 1500 byte packets for the MTU even if MTU is configured at 4470
For an OC3 link, P is determined as follows:
P = 100ms * 155Mbps / (1500 * 8) = 12917