Configuration Guidelines; Mapping Cos Values To An Egress Queue And To A Threshold Id - Cisco Catalyst 2928 Software Configuration Manual

Chapter 31 Configuring QoS
These sections contain this configuration information:
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Configuration Guidelines

Follow these guidelines when the expedite queue is enabled or the egress queues are serviced based on
their SRR weights:
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Mapping CoS Values to an Egress Queue and to a Threshold ID

You can prioritize traffic by placing packets with particular costs of service into certain queues and
adjusting the queue thresholds so that packets with lower priorities are dropped.
Note The egress queue default settings are suitable for most situations. You should change them only when
you have a thorough understanding of the egress queues and if these settings do not meet your QoS
solution.
Beginning in privileged EXEC mode, follow these steps to map CoS values to an egress queue and to a
threshold ID. This procedure is optional.
Command
Step 1 configure terminal
Step 2 mls qos srr-queue output cos-map
queue queue-id threshold threshold-id
cos1...cos8
Step 3
end
OL-23389-01
Configuration Guidelines, page 31-15
Mapping CoS Values to an Egress Queue and to a Threshold ID, page 31-15
Configuring the Egress Expedite Queue, page 31-16
Displaying Standard QoS Information, page 31-17
If the egress expedite queue is enabled, it overrides the SRR shaped and shared weights for queue 1.
If the egress expedite queue is disabled and the SRR shaped and shared weights are configured, the
shaped mode overrides the shared mode for queue 1, and SRR services this queue in shaped mode.
If the egress expedite queue is disabled and the SRR shaped weights are not configured, SRR
services this queue in shared mode.
Purpose
Enter global configuration mode.
Map CoS values to an egress queue and to a threshold ID.
By default, CoS values 0 and 1 are mapped to queue 2 and threshold 1.
CoS values 2 and 3 are mapped to queue 3 and threshold 1. CoS values 4,
6, and 7 are mapped to queue 4 and threshold 1. CoS value 5 is mapped to
queue 1 and threshold 1.
Return to privileged EXEC mode.
(optional)
For queue-id, the range is 1 to 4.
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For threshold-id, the range is 1 to 3. The drop-threshold percentage
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for threshold 3 is predefined. It is set to the queue-full state.
• For cos1...cos8, enter up to eight values, and separate each value with
a space. The range is 0 to 7.
Catalyst 2928 Switch Software Configuration Guide
Configuring Standard QoS
(optional)
(optional)
31-15