Cisco IE 3000 User Manual

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Cisco IE 3000 Switch Software Configuration Guide
OL-13018-01
Chapter 32 Configuring QoS
Configuring Standard QoS
Mapping DSCP or CoS Values to an Egress Queue and to a Threshold ID
You can prioritize traffic by placing packets with particular DSCPs or 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 DSCP or CoS values to an egress queue
and to a threshold ID. This procedure is optional.
To return to the default DSCP output queue threshold map or the default CoS output queue threshold
map, use the no mls qos srr-queue output dscp-map or the no mls qos srr-queue output cos-map
global configuration command.
Command Purpose
Step 1
configure terminal Enter global configuration mode.
Step 2
mls qos srr-queue output dscp-map
queue queue-id threshold threshold-id
dscp1...dscp8
or
mls qos srr-queue output cos-map
queue queue-id threshold threshold-id
cos1...cos8
Map DSCP or CoS values to an egress queue and to a threshold ID.
By default, DSCP values 0–15 are mapped to queue 2 and threshold 1.
DSCP values 16–31 are mapped to queue 3 and threshold 1. DSCP values
32–39 and 48–63 are mapped to queue 4 and threshold 1. DSCP values
40–47 are mapped to queue 1 and threshold 1.
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.
• For queue-id, the range is 1 to 4.
• For threshold-id, the range is 1 to 3. The drop-threshold percentage
for threshold 3 is predefined. It is set to the queue-full state.
• For dscp1...dscp8, enter up to eight values, and separate each value
with a space. The range is 0 to 63.
• For cos1...cos8, enter up to eight values, and separate each value with
a space. The range is 0 to 7.
Step 3
end Return to privileged EXEC mode.
Step 4
show mls qos maps Verify your entries.
The DSCP output queue threshold map appears as a matrix. The d1
column specifies the most-significant digit of the DSCP number; the d2
row specifies the least-significant digit in the DSCP number. The
intersection of the d1 and the d2 values provides the queue ID and
threshold ID; for example, queue 2 and threshold 1 (02-01).
The CoS output queue threshold map shows the CoS value in the top row
and the corresponding queue ID and threshold ID in the second row; for
example, queue 2 and threshold 2 (2-2).
Step 5
copy running-config startup-config (Optional) Save your entries in the configuration file.

Cisco IE 3000 Specifications

General

Brand	Cisco
Model	IE 3000
Category	Switch
Language	English