Service Manual

The following is a list of the Dell Networking OS version history for this command.
Version Description
9.7(0.0) Introduced on the S6000-ON.
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.
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 weight
Congure the weight factor for computation of average-queue size. This weight value applies to front-end ports. This mechanism to
congure a weight for WRED and ECN functionality for front-end ports is supported on the S6000 and Z9000 platforms.
S6000–ON
Syntax
[no] wred weight number
Parameters
weight Dene the weight factor to be used for computation of the WRED average-queue
size to either enable WRED to discard packets or cause ECN to mark packets that
exceed the minimum threshold congured. This setting applies to front-end ports
only.
number Enter the weight as a number to be used to calculate the average-queue size. The
range is 1 to 15. The default is 0.
Default The default weight is zero.
Command Modes QOS-POLICY-OUT mode
Command History
Version Description
9.7(0.0) Introduced on the S6000-ON.
Quality of Service (QoS)
1109