Cisco Catalyst 3560-X Series, Software Configuration Manual

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Catalyst 3750-X and 3560-X Switch Software Configuration Guide
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Chapter 1 Configuring QoS
Configuring Standard QoS
Default Standard QoS Configuration
QoS is disabled. There is no concept of trusted or untrusted ports because the packets are not modified
(the CoS, DSCP, and IP precedence values in the packet are not changed). Traffic is switched in
pass-through mode (packets are switched without any rewrites and classified as best effort without any
policing).
When QoS is enabled with the mls qos global configuration command and all other QoS settings are at
their defaults, traffic is classified as best effort (the DSCP and CoS value is set to 0) without any policing.
No policy maps are configured. The default port trust state on all ports is untrusted. The default ingress
and egress queue settings are described in the
“Default Ingress Queue Configuration” section on
page 1-37 and the “Default Egress Queue Configuration” section on page 1-38 .
Default Ingress Queue Configuration
Table 1-6 shows the default ingress queue configuration when QoS is enabled.
Table 1-7 shows the default CoS input queue threshold map when QoS is enabled.
Table 1-8 shows the default DSCP input queue threshold map when QoS is enabled.
Table 1-6 Default Ingress Queue Configuration
Feature Queue 1 Queue 2
Buffer allocation 90 percent 10 percent
Bandwidth allocation
1
1. The bandwidth is equally shared between the queues. SRR sends packets in shared mode only.
4 4
Priority queue bandwidth
2
2. Queue 2 is the priority queue. SRR services the priority queue for its configured share before servicing the other queue.
0 10
WTD drop threshold 1 100 percent 100 percent
WTD drop threshold 2 100 percent 100 percent
Table 1-7 Default CoS Input Queue Threshold Map
CoS Value Queue ID–Threshold ID
0–4 1 – 1
5 2
–
1
6, 7 1 – 1
Table 1-8 Default DSCP Input Queue Threshold Map
DSCP Value Queue ID–Threshold ID
0–39 1 – 1
40–47 2 – 1
48–63 1 – 1