Reference Guide

Command Modes CONFIGURATION (conf-qos-policy-out)
Command History
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.
• If neither endpoint is ECN-capable, the packet may be dropped based on the WRED
drop probability. This is the identical treatment that a packet receives when WRED is
enabled without ECN configured on the router.
• If the network is experiencing congestion, the packet is transmitted. No further
marking is required.
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 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.
E-Series, Z-Series, S4810
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 (16 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
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