Configuring Standard QoS
Command
Step 1
configure terminal
Step 2
mls qos queue-set output qset-id
buffers allocation1 ... allocation4
Step 3
mls qos queue-set output qset-id
threshold queue-id drop-threshold1
drop-threshold2 reserved-threshold
maximum-threshold
Step 4
interface interface-id
Step 5
queue-set qset-id
Step 6
end
Step 7
show mls qos interface [interface-id]
buffers
Step 8
copy running-config startup-config
Catalyst 3750 Metro Switch Software Configuration Guide
26-70
Purpose
Enter global configuration mode.
Allocate buffers to a queue-set.
By default, all allocation values are equally mapped among the four
queues (25, 25, 25, 25). Each queue has 1/4 of the buffer space.
•
For qset-id, enter the ID of the queue-set. The range is 1 to 2. Each
port belongs to a queue-set, which defines all the characteristics of the
four egress queues per port.
•
For allocation1 ... allocation4, specify four percentages, one for each
queue in the queue-set. The range is 0 to 100. Separate each value
with a space.
Allocate buffers according to the importance of the traffic. For example,
give a larger percentage of the buffer to the queue with the highest-priority
traffic.
Configure the WTD thresholds, guarantee the availability of buffers, and
configure the maximum memory allocation for the queue-set (four egress
queues per port).
By default, the WTD thresholds for queues 1, 3, and 4 are set to 100
percent. The thresholds for queue 2 are set to 50 percent. The reserved
thresholds for queues 1, 3, and 4 are set to 50 percent. The reserved
threshold for queue 2 is set to 100 percent. The maximum thresholds for
all queues are set to 400 percent.
•
For qset-id, enter the ID of the queue-set specified in Step 2. The
range is 1 to 2.
•
For queue-id, enter the specific queue in the queue-set on which the
command is performed. The range is 1 to 4.
•
For drop-threshold1 drop-threshold2, specify the two WTD
thresholds expressed as a percentage of the queue's allocated
memory. The range is 1 to 400 percent.
For reserved-threshold, enter the amount of memory to be guaranteed
•
(reserved) for the queue expressed as a percentage of the allocated
memory. The range is 1 to 100 percent.
For maximum-threshold, enable a full queue to obtain more buffers
•
than are reserved for it. This is the maximum memory the queue can
have before the packets are dropped if the common pool is not empty.
The range is 1 to 400 percent.
Specify the port, and enter interface configuration mode.
Map the port to a queue-set.
For qset-id, enter the ID of the queue-set specified in Step 2. The range is
1 to 2. The default is 1.
Return to privileged EXEC mode.
Verify your entries.
(Optional) Save your entries in the configuration file.
Chapter 26
Configuring QoS
78-15870-01