Service Manual

● 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.
S4048–ON
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.
If green profile is applied, default yellow also take effect and vice-versa.
Command Modes CONFIGURATION
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
9.8(0.0P5) Introduced on the S4048-ON.
9.8(0.0P2) Introduced on the S3048-ON.
9.7(0.0) Introduced on the S6000-ON.
9.2(1.0) Introduced on the Z9500.
9.0.2.0 Introduced on the S6000.
8.3.19.0 Introduced on the S4820T.
8.3.11.1 Introduced on the Z9000.
8.3.7.0 Introduced on the S4810.
6.1.1.1 Introduced on the E-Series.
Usage
Information
Use the default pre-defined profiles or configure your own profile. You cannot delete the pre-defined
profiles or their default values. This command enables WRED configuration mode —(conf-wred).
1190 Quality of Service (QoS)