Reference Guide

Version 8.2.1.0 Profile name character limit increased from 16 to 32.
pre-Version
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 ecn
To indicate network congestion, rather than dropping packets, use explicit congestion notification (ECN).
Z9000
Syntax
wred ecn
To stop marking packets, use the no wred ecn command.
Defaults none
Command
Modes
CONFIGURATION (conf-qos-policy-out)
Command
History
This guide is platform-specific. For command information about other platforms,
refer to the relevant Dell Networking OS Command Line Reference Guide.
The following is a list of the Dell Networking OS version history for this command.
Version 9.0.2.0 Introduced on the S6000.
Version
8.3.19.0
Introduced on the S4820t.
Version 8.3.11.1 Introduced on the Z9000.
Version 8.3.7.0 Introduced on the S4810.
Usage
Information
When you enable wred ecn, and the number of packets in the queue is below the
minimum threshold, packets are transmitted per the usual WRED treatment.
When you enable wred ecn, and the number of packets in the queue is between
the minimum threshold and the maximum threshold, one of the following three
scenarios can occur:
• If the transmission endpoints are ECN-capable and traffic is congested, and the
WRED algorithm determines that the packet should have been dropped based
on the drop probability, the packet is transmitted and marked so the routers
know the system is congested and can slow transmission rates.
1272
Quality of Service (QoS)