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Cisco IOS Software Configuration Guide for Cisco Aironet Access Points
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Chapter15 Configuring QoS
Understanding QoS for Wireless LANs
The access point uses WMM enhancements in packets sent to client devices that support WMM. The
access point applies basic QoS policies to packets sent to clients that do not support WMM.
Use the no dot11 qos mode wmm configuration interface command to disable WMM using the CLI. To
disable WMM using the web-browser interface, unselect the check boxes for the radio interfaces on the
QoS Advanced page. Figure 15-3 shows the QoS Advanced page.
Using Band Select
Band Select allows you to move dual-band capable wireless clients joining the cell, to the less congested
5 GHz radio, if your SSID is available on both radios. This feature improves the overall performance of
the network.
When the Band Select feature is enabled, the access point delays the probe responses on the 2.4 GHz
radio to all new clients, for all SSIDs that are Band Select-enabled. At the same time, the access point
does not delay the probe responses on the 5 GHz radio. This mechanism allows dual-band clients to
discover the SSID on the 5 GHz radio first, thus pushing these clients to associate to the SSID on the AP
5 GHz radio instead of the 2.4 Ghz radio. Only those clients that are 2.4 GHz-only will stay on the 2.4
GHz radio.
To enable Band Select, follow these steps:
Step1 Choose Security > SSID Manager.
Step2 Click NEW to create a new SSID.
or
Choose the required SSID from the Current SSID.
Step3 Click the Band Select radio button.
Step4 Click Apply.
Note The band select feature is useful only if the SSID is assigned to both radios.
When a client actively discovers a network, that client sends probe requests on one or several channels.
A typical behavior is to send a burst of probe requests on a given channel, collect the replies from the
responding APs, and then move to the next channel. For this reason, two consecutive probe requests
received on a given channel does not necessarily indicate two attempts to discover APs on a channel, but
may be part of the same scan cycle through a burst.
You can fine tune the Band Select behavior to determine information such as:
•How long a scan cycle is expected to last
•The number of cycles during which an AP will not respond to probe request from a client on a
2.4 GHz channel, along with client RSSI
•Timeout for the Band Select mechanism to be triggered.
To assign the parameters for Band Select, follow these steps:
Step1 Choose Services > Band Select.
Step2 Check the Band Select check box.