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Hierarchy Level

Release Information

Statement introduced in Junos OS Release 8.3.


Configure the IQ PIC to base random early detection (RED) queue management on a simple moving average buffer occupancy calculation. If you do not include this statement, the IQ PIC bases RED on an instantaneous buffer occupancy value. As an option, you can specify that the IQ PIC bases RED on a weighted moving average of buffer occupancy values.

If you configure this feature on a channelized OC12 intelligent queuing (IQ) PIC, the PIC reboots.


weighted-averaged—Configure the IQ PIC to base RED processing on a simple moving average of instantaneous buffer occupancy values instead of an instantaneous buffer occupancy.

instant-usage-weight-exponent exponent-value—(Optional) Specify the integer to be used as the negative exponent of 2 to express a weight value. The PIC performs weighted RED (WRED) by based on a calculation of average buffer occupancy that applies the specified weight value to the instantaneous buffer occupancy and then factors the weighted value into the calculation of average buffer occupancy. Valid exponent range is from 1 through 31 (weight values from 2-1 through 2-31). If you do not specify this option, the default exponent value is 0, which results in a weight value of 20 = 1. With a weight value of 1, the calculation of weighted average buffer occupancy yields the same value as the simple average buffer occupancy.


You can specify an exponent value greater than 31, and the value displays in the output of show commands. However, the PIC replaces the out-of-range value with the operational value of 31, which results in a weight value of 2-31 = 1 / 231 = 0.0000000004656612873077392578125.

Required Privilege Level

interface—To view this statement in the configuration.

interface-control—To add this statement to the configuration.