Cisco 7609 Configuration Manual page 453

Chapter 32 Configuring PFC QoS
Note •
•
•
When configuring thresholds, note the following:
•
•
When you configure multiple-threshold standard queues, note the following:
•
•
•
•
•
When configuring the WRED-drop thresholds, note the following:
•
•
•
•
•
Configuring a Tail-Drop Receive Queue
These port types have only tail-drop thresholds in their receive-queues:
•
•
78-14064-04
Enter the show queueing interface {ethernet | fastethernet | gigabitethernet |
tengigabitethernet} slot/port | include type command to see the queue structure of a port (see the
"Receive Queues" section on page 32-13
1p1q0t ports have no configurable thresholds.
1p3q1t (transmit), 1p2q1t (transmit), and 1p1q8t (receive) ports also have nonconfigurable
tail-drop thresholds (see the
section on page 32-61).
Queue number 1 is the lowest-priority standard queue.
Higher-numbered queues are higher priority standard queues.
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.
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.
1p1q4t
1q2t
and the "Transmit Queues" section on page
"Mapping CoS Values to Standard Transmit-Queue Thresholds"
Cisco 7600 Series Router Cisco IOS Software Configuration Guide—12.1E
Configuring PFC QoS
32-21).
32-55