Brocade FastIron Ethernet Switch Traffic Management Guide User Manual
Page 42
Default minimum bandwidth percentages on Brocade devices
TABLE 24
Queue
Default minimum percentage of bandwidth
Without jumbo frames
With jumbo frames
qosp7
75%
44%
qosp6
7%
8%
qosp5
3%
8%
qosp4
3%
8%
qosp3
3%
8%
qosp2
3%
8%
qosp1
3%
8%
qosp0
3%
8%
When the queuing method is WRR, the software internally translates the percentages into weights.
The weight associated with each queue controls how many packets are processed for the queue at a
given stage of a cycle through the weighted round robin algorithm.
NOTE
Queue cycles on the Brocade FastIron devices are based on bytes. These devices service a given
number of bytes (based on the weight) in each queue cycle.
The bandwidth allocated to each queue is based on the relative weights of the queues. You can
change the bandwidth percentages allocated to the queues by changing the queue weights.
There is no minimum bandwidth requirement for a given queue. For example, queue qosp3 is not
required to have at least 50 percent of the bandwidth.
To change the bandwidth percentages for the queues, enter commands such as the following. Note
that this example uses the default queue names.
device(config)#qos profile qosp7 25 qosp6 15 qosp5 12 qosp4 12 qosp3 10 qosp2
10 qosp1 10 qosp0 6
Profile qosp7 : Priority7 bandwidth requested 25% calculated 25%
Profile qosp6 : Priority6 bandwidth requested 15% calculated 15%
Profile qosp5 : Priority5 bandwidth requested 12% calculated 12%
Profile qosp4 : Priority4 bandwidth requested 12% calculated 12%
Profile qosp3 : Priority3 bandwidth requested 10% calculated 10%
Profile qosp2 : Priority2 bandwidth requested 10% calculated 10%
Profile qosp1 : Priority1 bandwidth requested 10% calculated 10%
Profile qosp0 : Priority0 bandwidth requested 6% calculated 6%
Syntax: [no] qos profile name7 { sp | percentage } name6 { sp | percentage } name5 { sp |
percentage } name4 { sp | percentage } name3 { sp | percentage } name2 { sp | percentage } name1 {
sp | percentage } name0 { sp | percentage }
Each queue variable specifies the name of a queue. You can specify the queues in any order on the
command line, but you must specify each queue.
The percentage variable specifies a number for the percentage of the device outbound bandwidth that
is allocated to the queue. Brocade QoS queues require a minimum bandwidth percentage of 3 percent
Quality of Service
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FastIron Ethernet Switch Traffic Management Guide
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