Users Guide

Version Description
8.2.1.0 Profile name character limit increased from 16 to 32.
6.1.1.1 Introduced on the .E-Series
Usage
Information
To assign drop precedence to green or yellow traffic, use this command. If there is no honoring enabled
on the input, all the traffic defaults to green drop precedence.
Related
Commands
wred-profile — creates a WRED profile and name that profile.
trust — defines the dynamic classification to trust DSCP.
wred weight
Configure the weight factor used to determine the average-queue size for WRED and ECN operation. The weight value is used
in an output QoS policy applied to a front-end or backplane port.
C9000 Series
Syntax
[no] wred weight number
Parameters
weight Define the weight factor to be used for computation of the WRED average-queue
size to either enable WRED to discard packets or cause ECN to mark packets that
exceed the minimum threshold configured. This setting applies to front-end and
backplane ports.
number Enter the weight as a number to be used to calculate the average-queue size. The
range is 1 to 15. The default is 0.
Default The default weight is zero.
Command Modes QOS-POLICY-OUT mode
Command
History
Version Description
9.9(0.0) Introduced on the C9010.
9.2.1.0 Introduced on the Z9500 switch.
9.3.0.0 Introduced on the S6000 and Z9000 platforms
Usage
Information
If the average queue size is more than the maximum threshold of WRED, the packet is dropped. If the
average queue size is between the minimum and maximum threshold values, the decision to drop or queue
the packet is taken based on the packet drop probability. The probability that a packet is dropped
depends on the minimum threshold, maximum threshold, and mark probability denominator.
Example
Dell(conf-qos-policy-out)# wred weight 5
wred ecn
To indicate network congestion without dropping packets, use explicit congestion notification (ECN).
C9000 Series
Syntax
wred ecn
To stop marking packets, use the no wred ecn command.
Defaults none
1372 Quality of Service (QoS)