Users Guide

Version Description
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 two scenarios can occur:
• If the transmission endpoints are ECN-capable and trac 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
congured 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 congured on the router.
Related Commands
wred-prole — creates a WRED prole and name that prole.
wred-prole
Create a WRED prole and name the prole.
S4820T
Syntax
wred-profile wred-profile-name
To remove an existing WRED prole, use the no wred-profile command.
Parameters
wred-prole-name
Enter your WRED prole name in character format (32 character maximum). Or
use one of the pre-dened WRED prole names. You can congure up to 26 WRED
proles plus the ve pre-dened proles, for a total of 31 WRED proles.
Pre-dened Proles: wred_drop, wred-ge_y, wred_ge_g, wred_teng_y,
wred_teng_g.
Defaults The ve pre-dened WRED proles. When you congure a new prole, the minimum and maximum
threshold defaults to predened wred_ge_g values.
If green prole is applied, default yellow also take eect and vice-versa.
Command Modes CONFIGURATION
Command History
This guide is platform-specic. 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.
1256
Quality of Service (QoS)