41-94
Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX
OL-4266-08
Chapter 41 Configuring PFC QoS
Configuring PFC QoS
•
Configuring a WRED-Drop and Tail-Drop Transmit Queue, page 41-96
•
Configuring 1q4t/2q2t Tail-Drop Threshold Percentages, page 41-98
Note
•
Enter the
show queueing interface
{
ethernet
|
fastethernet
|
gigabitethernet
|
tengigabitethernet
}
slot/port
|
include type
command to see the queue structure of a port.
•
1p1q0t
ports have no configurable thresholds.
•
1p3q1t
(transmit),
1p2q1t
(transmit), and
1p1q8t
(receive) ports also have nonconfigurable
tail-drop thresholds.
When configuring thresholds, note the following information:
•
Queue number 1 is the lowest-priority standard queue.
•
Higher-numbered queues are higher priority standard queues.
•
Receive-queue parameters can be configured only on trusted ports.
•
When configuring minimum and maximum threshold values, you cannot configure minimum values
to be larger than maximumvalues.
When you configure multiple-threshold standard queues, note the following information:
•
The first percentage that you enter sets the lowest-priority threshold.
•
The second percentage that you enter sets the next highest-priority threshold.
•
The last percentage that you enter sets the highest-priority threshold.
•
The percentages range from 1 to 100. A value of 10 indicates a threshold when the buffer is
10-percent full.
•
Always set highest-numbered threshold to 100 percent.
When configuring the WRED-drop thresholds, note the following information:
•
Each WRED-drop threshold has a low-WRED and a high-WRED value.
•
Low-WRED and high-WRED values are a percentage of the queue capacity (the range is from 1
to 100).
•
The low-WRED value is the traffic level under which no traffic is dropped. The low-WRED value
must be lower than the high-WRED value.
•
The high-WRED value is the traffic level above which all traffic is dropped.
•
Traffic in the queue between the low- and high-WRED values has an increasing chance of being
dropped as the queue fills.
Configuring a Tail-Drop Receive Queue
These port types have only tail-drop thresholds in their receive-queues:
•
1q2t
•
1p1q4t
•
2q8t
•
1q8t
