min-threshold and max-threshold in random-detect

[waimen]

Hi all,

Can anybody tell me what will do when get the min-threshold and max-threshold in random-detect? in random-detect, the command "random-detect precedence 0 x y z"(suppose use precedence based) x is min-threshold, y is max-threshold, z is mark-prob-denominator. to my knowledge, when the queue load get x, 1/z of the incoming packet will drop, but I don't know what will happen when get the max-threshold? Can anybody help me? Thank You!

Waimen

[ives.dekoninck]

Waimen,

If it gets to max-threshold, all packets will be dropped.

-Ives-

[tepatel]

Here is the url which discuss that..it willanswer all your questions

http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122newft/122tcr/122tqr/qftcmd7.htm#1066025

[omohamed]

When the average queue depth is above the minimum threshold, WRED starts dropping packets. The rate of packet drop increases linearly as the average queue size increases until the average queue size reaches the maximum threshold. The minimum threshold value should be set high enough to maximize the link utilization. If the minimum threshold is too low, packets may be dropped unnecessarily, and the transmission link will not be fully used. Pls go through the link on cogestion avoidance as it walks you through with how WRED works.

http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fqos_c/fqcprt3/qcfconav.htm#xtocid6