Users Guide

Classifying VoIP Traffic and Applying QoS Policies
You can avoid congestion and give precedence to voice and signaling traffic by classifying traffic based on the subnet and using strict
priority and bandwidth weights on egress, as outlined in the following steps. The following figure depicts the topology and configuration for
a C9000 system.
Figure 119. PoE VoIP Traffic
To classify VoIP traffic and apply QoS policies for an office VoIP deployment, use the following commands:
1 Create three standard or extended access-lists, one each for voice, voice signaling, and PC data, and place each in its own match-any
class-map.
CONFIGURATION mode or CLASS-MAP mode
ip access-list or class-map match-any
2 Create an input policy-map containing all three class-maps and assign each class-map a different service queue.
CONFIGURATION mode or POLICY-MAP-IN mode
policy-map-input or service-queue
3 Create two input QoS policies, one each for PC data and voice signaling. Assign a different bandwidth weight to each policy.
CONFIGURATION mode or QOS-POLICY-IN mode
qos-policy-out or bandwidth-weight
4 Create an output policy map containing both QoS policies and assign them to different service queues.
CONFIGURATION mode or POLICY-MAP-OUT mode
policy-map-out or service-queue
5 Assign a strict priority to unicast traffic in queue 3.
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Power over Ethernet (PoE)