Cisco WS-X6066-SLB-APC - Content Switching Module Software Manual page 718

Understanding How QoS Works
1q4t ports have this default drop-threshold configuration:
Using receive-queue drop threshold 1, the switch drops incoming frames with CoS 0 or 1 when the
•
receive-queue buffer is 50 percent or more full.
Using receive-queue drop threshold 2, the switch drops incoming frames with CoS 2 or 3 when the
•
receive-queue buffer is 60 percent or more full.
• Using receive-queue drop threshold 3, the switch drops incoming frames with CoS 4 or 5 when the
receive-queue buffer is 80 percent or more full.
Using receive-queue drop threshold 4, the switch drops incoming frames with CoS 6 or 7 when the
•
receive-queue buffer is 100 percent full.
1p1q4t ports have this default drop-threshold configuration:
Frames with CoS 0, 1, 2, 3, 4, 6, or 7 go to the standard receive queue:
•
Frames with CoS 5 go to the strict-priority receive queue (queue 2), where the switch drops
•
incoming frames only when the strict-priority receive-queue buffer is 100 percent full.
1p1q0t ports have this default drop-threshold configuration:
Frames with CoS 0, 1, 2, 3, 4, 6, or 7 go to the standard receive queue. The switch drops incoming
•
frames when the receive-queue buffer is 100 percent full.
Frames with CoS 5 go to the strict-priority receive queue (queue 2), where the switch drops
•
incoming frames only when the strict-priority receive-queue buffer is 100 percent full.
The explanations in this section use default values. You can configure many of the parameters (for
Note
more information, see the
the same drop-threshold configuration.
Figure 41-8
similarly.
Catalyst 6000 Family Software Configuration Guide—Releases 6.3 and 6.4
41-12
– Using standard receive-queue drop threshold 1, the switch drops incoming frames with CoS 0
or 1 when the receive-queue buffer is 50 percent or more full.
Using standard receive-queue drop threshold 2, the switch drops incoming frames with CoS 2
–
or 3 when the receive-queue buffer is 60 percent or more full.
Using standard receive-queue drop threshold 3, the switch drops incoming frames with CoS 4
–
when the receive-queue buffer is 80 percent or more full.
Using standard receive-queue drop threshold 4, the switch drops incoming frames with CoS 6
–
or 7 when the receive-queue buffer is 100 percent full.
"Configuring QoS" section on page
shows the drop thresholds for a 1q4t port. Drop thresholds in other configurations function
Chapter 41
41-30). All ports of the same type use
Configuring QoS
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