34-30
Catalyst 3560 Switch Software Configuration Guide
OL-8553-06
Chapter 34 Configuring QoS
Configuring Standard QoS
show mls qos maps [cos-dscp | cos-input-q | cos-output-q | dscp-cos | dscp-input-q |
dscp-output-q]
show mls qos input-queue
show running-config
For more information about these commands, see the command reference for this release.
Configuring Standard QoS
Before configuring standard QoS, you must have a thorough understanding of these items:
The types of applications used and the traffic patterns on your network.
Traffic characteristics and needs of your network. Is the traffic bursty? Do you need to reserve
bandwidth for voice and video streams?
Bandwidth requirements and speed of the network.
Location of congestion points in the network.
These sections contain this configuration information:
Default Standard QoS Configuration, page 34-30
Standard QoS Configuration Guidelines, page 34-33
Enabling QoS Globally, page 34-35 (required)
Enabling VLAN-Based QoS on Physical Ports, page 34-35 (optional)
Configuring Classification Using Port Trust States, page 34-36 (required
Configuring a QoS Policy, page 34-42 (required)
Configuring DSCP Maps, page 34-60 (optional, unless you need to use the
DSCP-to-DSCP-mutation map or the policed-DSCP map)
Configuring Ingress Queue Characteristics, page 34-66 (optional)
Configuring Egress Queue Characteristics, page 34-70 (optional)

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 34-31 and the “Default Egress Queue Configuration” section on page 34-31.