Brocade Multi-Service IronWare QoS and Traffic Management Configuration Guide (Supporting R05.6.00) - Manual (Page 138)

124 Multi-Service IronWare QoS and Traffic Management Configuration Guide
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Configuring packet drop priority using WRED
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Brocade(config)#qos queue-type 1 wred drop-precedence 0 min-avg-queue-size 16
Syntax: [no] qos queue-type queue-type wred drop-precedence drop-precedence-value
min-avg-queue-size min-size
The queue-type variable is the number of the forwarding queue type that you want to configure
drop-precedence for. There are eight forwarding queue types on Brocade devices. They are
numbered 0 to 7.
The drop-precedence-value variable for the drop-precedence parameter is the TOS or DSCP value
in the IPv4 or IPv6 packet header. It determines drop precedence on a scale from 0 - 3. Packets
than contain a DSCP value of 0 are least likely to be dropped and packets with a value of 3 are
most likely to be dropped. The default value is 0.
The min-size variable is the average queue size below which all packets are accepted. Possible
values are 1 - 32768 KBytes. It must be set in multiples of 64K. The default values are shown in
Table 31 .
The max-size variable is the average queue size above which all packets are dropped. (1 - 32768)
(KBytes) in multiples of 64K. The default values are shown in
Table 31 .
Setting the maximum packet size
To set the maximum packet size to 16 bytes for queue type 1 and drop precedence 0, use the
following command.
Brocade(config)#qos queue-type 1 wred drop-precedence 0 packet-size-max 16
Syntax: [no] qos queue-type queue-type wred drop-precedence drop-precedence-value
packet-size-max pkt-size
The queue-type variable is the number of the forwarding queue type that you want to configure
drop-precedence for. There are eight forwarding queue types on Brocade devices. They are
numbered 0 to 7.
The drop-precedence-value variable for the drop-precedence parameter is the TOS or DSCP value
in the IPv4 or IPv6 packet header. It determines drop precedence on a scale from 0 - 3. Packets
than contain a DSCP value of 0 are least likely to be dropped and packets with a value of 3 are
most likely to be dropped. The default value is 0.
The pkt-size variable is the pkt-size-max variable used in the equation described in “Calculating
packets that are dropped” on page 119. Permissible values are an even number of bytes between
16 and 32768. The default values are shown for each queue type and drop precedence value in
Table 31 .
Restoring default WRED parameters
Table 31 describes all of the default values for each of the WRED parameters. If you change any of
the values from the default values, you can restore the defaults per queue type. To reset the queue
type 1 with default values for the WRED parameters, use the following command.
Brocade(config)#qos queue-type 1 wred default-params
Syntax: [no] qos queue-type queue-number default-params
The queue-number variable is the number of the forwarding queue that you want to configure
drop-precedence for. There are eight forwarding queues on Brocade devices. They are numbered 0
to 7