Users Guide

Command Modes QOS-POLICY-OUT mode
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 Description
9.9(0.0) Introduced on the C9010.
9.2(1.0) Introduced on the Z9500.
8.3.19.0 Introduced on the S4820t.
8.3.11.1 Introduced on the Z9000.
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 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.
● If neither endpoint is ECN-capable, the packet may be dropped based on the WRED drop probability.
This behavior is the identical treatment that a packet receives when WRED is enabled without ECN
configured on the router.
When you enable wred ecn, and the number of packets in the queue is above the maximum threshold,
packets are dropped based on the drop probability. This behavior is the identical treatment a packet
receives when WRED is enabled without ECN configured on the router.
Related
Commands
wred-profile — creates a WRED profile and name that profile.
wred-profile
Create a WRED profile and name the profile.
C9000 Series
Syntax
wred-profile wred-profile-name
To remove an existing WRED profile, use the no wred-profile command.
Parameters
wred-profile-
name
Enter your WRED profile name in character format (32 character maximum). Or
use one of the pre-defined WRED profile names. You can configure up to 26 WRED
profiles plus the five pre-defined profiles, for a total of 31 WRED profiles.
Pre-defined Profiles: wred_drop, wred-ge_y, wred_ge_g, wred_teng_y,
wred_teng_g.
Defaults The five pre-defined WRED profiles. When you configure a new profile, the minimum and maximum
threshold defaults to predefined wred_ge_g values.
Command Modes
CONFIGURATION
CONFIGURATION TERMINAL BATCH
Command
History
This guide is platform-specific. For command information about other platforms, refer to the relevant Dell
Networking OS Command Line Reference Guide.
Quality of Service (QoS) 1373