D-Link xStack DES-3800 Series User Manual page 189

To configure WRED settings for the Switch, configure the following fields and click Apply. Note that WRED State may be
separately globally enabled and disabled and has its own Apply button for this reason.
Parameter Description
WRED State Allows the user to globally enable and disable the WRED function on this switch without altering
previously made configurations. Use the pull-down menu and click the Apply button, located
directly adjacent to the WRED State configuration field.
Port List Use the pull-down menus to select a port or range of ports to be configured for WRED.
Class ID Select the CoS ID, from 0-7, to configure for the WRED parameters. Selecting all will set the
parameters configured here for all CoS queues.
Cfg. Parameter Use the pull-down menu if you desire to configure a particular parameter of the WRED settings
for a specified queue or port. The user may choose All Parameters, which will allow the user to
configure Drop Start, Drop Slope and Average Time, simultaneously for a desired CoS queue, or
select a specific parameter only to be configured. These parameters can be configured in the
following three fields.
Drop Start Select a percentage between 0 and 100 to initialize the discarding of random packets. This
percentage is based on the fill percentage of the egress QoS queue stated in the Class ID field.
(Once the specified queue reaches the target percentage specified here, the Switch will begin
randomly discarding packets)
Drop Slope The drop slop is a formula resulting in a degree which compares the average size of a queue to
the percentage of the maximum and minimum Drop Start function previously stated. A value
closer to 90° will wait a longer time before dropping packets than a value set closer to 0°.
Average Time Enter a time, in microseconds, that the Switch will check the CoS queues to determine
abnormalities in the settings and boundaries which will trigger the WRED function to initialize.
Click Apply to implement changes made.
xStack DES-3800 Series Layer 3 Stackable Fast Ethernet Managed Switch
174