Cisco Systems 3.2 Wireless Office Headset User Manual


 
6-10
Cisco Wireless LAN Controller Configuration Guide
OL-8335-02
Chapter 6 Configuring WLANs
Configuring Wireless LANs
Enabling 7920 Support Mode
The 7920 support mode contains two options:
Support for 7920 phones that require call admission control (CAC) to be configured on and
advertised by the client device (these are typically older 7920 phones)
Support for 7920 phones that require CAC to be configured on and advertised by the access point
(these are typically newer 7920 phones)
Note When access-point-controlled CAC is enabled, the access point sends out a Cisco proprietary
CAC Information Element (IE) and does not send out the standard QBSS IE.
Enter this command to enable 7920 support mode for phones that require client-controlled CAC:
config wlan 7920-support client-cac-limit {enabled | disabled} wlan-id
Note You cannot enable both WMM mode and client-controlled CAC mode on the same wireless
LAN.
Enter this command to enable 7920 support mode for phones that require access-point-controlled CAC:
config wlan 7920-support ap-cac-limit {enabled | disabled} wlan-id
QBSS Information Elements Sometimes Degrade 7920 Phone Performance
If your wireless LAN contains both 1000 series access points and Cisco 7920 wireless phones, do not
enable the WMM or AP-CAC-LIMIT QBSS information elements. Do not enter either of these
commands:
config wlan 7920-support ap-cac-limit enable wlan-id
config wlan wmm [allow | require] wlan-id
The information sent by 1000 series access points in the WMM and AP-CAC-LIMIT QBSS information
elements is inaccurate and could result in degradation of voice quality 7920 wireless phones. This issue
does not affect the CLIENT-CAC-LIMIT QBSS IE, which you enable using this command:
config wlan 7920-support client-cac-limit enable wlan-id
The CLIENT-CAC-LIMIT QBSS IE is the only QBSS IE that should be used in networks containing
both 1000 series access points and 7920 wireless phones.