Specifications

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Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
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Chapter 27 Configuring QoS
Configuring Standard QoS
This section describes how to configure standard QoS on your switch:
Note If your switch is running the SI, you can configure only the features described in the “Configuring
Classification Using Port Trust States” and the “Configuring the Egress Queues” sections. You can also
display the QoS information as described in the “Displaying Standard QoS Information” section.
• Default Standard QoS Configuration, page 27-16
• Configuration Guidelines, page 27-17
• Configuring Classification Using Port Trust States, page 27-17
• Configuring a QoS Policy, page 27-23
• Configuring CoS Maps, page 27-31
• Configuring the Egress Queues, page 27-34
Default Standard QoS Configuration
This is the default standard QoS configuration:
Note You can configure policy maps, policers, the CoS-to-DSCP map, and the DSCP-to-CoS map only if your
switch is running the EI.
• The default port CoS value is 0.
• The CoS value of 0 is assigned to all incoming packets.
• The default port trust state is untrusted.
• No policy maps are configured.
• No policers are configured.
• The default CoS-to-DSCP map is shown in Table 27-6.
• The default DSCP-to-CoS map is shown in Table 27-7.
• The default scheduling method for the egress queues is strict priority.
• For default CoS and WRR values, see the “Configuring the Egress Queues” section on page 27-34.
Note In software releases earlier than Release 12.1(11)EA1, the switch uses the CoS value of incoming
packets without modifying the DSCP value. You can configure this by enabling pass-through mode on
the port. For more information, see the “Enabling Pass-Through Mode” section on page 27-22.