Specifications

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Cisco IOS Software Configuration Guide for Cisco Aironet Access Points
OL-5260-01
Chapter 14 Configuring QoS
QoS Configuration Examples
Disabling IGMP Snooping Helper
When Internet Group Membership Protocol (IGMP) snooping is enabled on a switch and a client roams
from one access point to another, the client’s multicast session is dropped. When the access point’s
IGMP snooping helper is enabled, the access point sends a general IGMP query to the network
infrastructure on behalf of the client every time the client associates or reassociates to the access point.
By doing so, the multicast stream is maintained for the client as it roams.
The IGMP snooping helper is enabled by default. To disable it, browse to the QoS Policies - Advanced
page, select Disable, and click Apply. Figure 14-3 shows the QoS Policies - Advanced page.
Disabling AVVID Priority Mapping
AVVID priority mapping maps Ethernet packets tagged as class of service 5 to class of service 6. This
feature enables the access point to apply the correct priority to voice packets for compatibility with Cisco
AVVID networks.
AVVID priority mapping is enabled by default. To disable it, browse to the QoS Policies - Advanced
page, select No for Map Ethernet Packets with CoS 5 to CoS 6, and click Apply. Figure 14-3 shows the
QoS Policies - Advanced page.
QoS Configuration Examples
These sections describe two common uses for QoS:
• Giving Priority to Voice Traffic, page 14-10
• Giving Priority to Video Traffic, page 14-12
Giving Priority to Voice Traffic
This section demonstrates how you can apply a QoS policy to your wireless network’s voice VLAN to
give priority to wireless phone traffic.
In this example, the network administrator creates a policy named voice_policy that applies voice class
of service to traffic from Spectralink phones (protocol 119 packets). The user applies the voice_policy
to the incoming and outgoing radio ports and to the outgoing Ethernet port. Figure 14-5 shows the
administrator’s QoS Policies page.