Configuration Guide (Supporting R05.6.00) Manual

Multi-Service IronWare QoS and Traffic Management Configuration Guide 121
53-1003037-02
Configuring packet drop priority using WRED
4
Enabling WRED
WRED must be enabled for the queue type of any forwarding queue that you want it to operate on.
To enable WRED for the forwarding queues with a queue type of 3, enter the following command.
Brocade(config)#qos queue-type 3 wred enable
Syntax: [no] qos queue-type queue-number wred enable
The queue-type variable is the number of the forwarding queue that you want to enable WRED for.
There are eight forwarding queues on Brocade devices. They are numbered 0 to 7.
Default values are as described in Table 31. You can optionally adjust any of the pre-configured
parameters described there.
Setting the averaging-weight (Wq) parameter
The Wq parameter described in “Weighted Random Early Discard (WRED)” on page 118 is
configured as the averaging-weight parameter. In this implementation, you can set one of 13
(1 - 13) possible values. These values represent a Wq value as described in Table 30
To set the wq parameter for queues with a queue type of 1 to 25%, use the following command.
Brocade(config)#qos queue-type 1 wred averaging-weight 2
This gives the current queue size a weight of 25% over the statistical average queue size.
Syntax: [no] qos queue-type queue-type wred averaging-weight avg-weight-value
The queue-type variable is the number of the forwarding queue type that you want to configure the
averaging-weight (Wq) parameter for. There are eight forwarding queue types on Brocade devices.
They are numbered 0 to 7.
TABLE 30 Possible Wq values
Averaging weight setting Wq value as a percentage
1 50%
2 25%
3 12.5%
46.2%
5 3.12%
6 1.56%
7 0.78%
80.4%
90.2%
10 0.09%
11 0.05%
12 0.02%
13 0.01%