Cisco WS-X6148-FE-SFP= - Classic Interface Module Switch, Руководство пользователя программного обеспечения

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Catalyst 6000 Family Software Configuration Guide—Releases 6.3 and 6.4
78-13315-02
Chapter 41 Configuring QoS
Understanding How QoS Works
2q2t Ports
For 2q2t ports, each transmit queue has two drop thresholds that function as follows:
•
Frames with CoS 0, 1, 2, or 3 go to the low-priority transmit queue (queue 1):
–
Using transmit queue 1, drop-threshold 1, the switch drops frames with CoS 0 or 1 when the
low-priority transmit-queue buffer is 80 percent full.
– Using transmit queue 1, drop threshold 2, the switch drops frames with CoS 2 or 3 when the
low-priority transmit-queue buffer is 100 percent full.
•
Frames with CoS 4, 5, 6, or 7 go to the high-priority transmit queue (queue 2):
– Using transmit queue 2, drop threshold 1, the switch drops frames with CoS 4 or 5 when the
high-priority transmit-queue buffer is 80 percent full.
–
Using transmit queue 2, drop threshold 2, the switch drops frames with CoS 6 or 7 when the
high-priority transmit-queue buffer is 100 percent full.
1p2q2t Ports
For 1p2q2t ports, the low- and high-priority standard transmit queues each have two drop thresholds that
function as follows:
•
Frames with CoS 0, 1, 2, or 3 go to the low-priority standard transmit queue (queue 1):
– Using standard transmit queue 1, drop threshold 1, the switch drops frames with CoS 0 or 1
when the low-priority transmit-queue buffer is 80 percent full.
–
Using standard transmit queue 1, drop threshold 2, the switch drops frames with CoS 2 or 3
when the low-priority transmit-queue buffer is 100 percent full.
• Frames with CoS 4, 6, or 7 go to the high-priority standard transmit queue (queue 2):
–
Using standard transmit queue 2, drop threshold 1, the switch drops frames with CoS 4 when
the high-priority transmit-queue buffer is 80 percent full.
– Using standard transmit queue 2, drop threshold 2, the switch drops frames with CoS 6 or 7
when the high-priority transmit-queue buffer is 100 percent full.
•
Frames with CoS 5 go to the strict-priority transmit queue (queue 3), where the switch drops frames
only when the buffer is 100 percent full.
1p3q1t Ports
For 1p3q1t ports, the queues each have one drop threshold that function as follows:
•
Frames with CoS 0 and 1 go to the low-priority standard transmit queue (queue 1).
•
Frames with CoS 2, 3, or 4 go to the medium-priority standard transmit queue (queue 2).