Cisco Unified Wireless IP Phone 7925G Series Deployment Guide
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Call Admision Control (CAC) configuration
Voice AC - Admission control (ACM)............ Enabled
Voice max RF bandwidth........................ 75
Voice reserved roaming bandwidth.............. 6
Voice load-based CAC mode..................... Enabled
Voice tspec inactivity timeout................ Disabled
Video AC - Admission control (ACM)............ Disabled
Voice Stream-Size............................. 84000
Voice Max-Streams............................. 2
Video max RF bandwidth........................ 25
Video reserved roaming bandwidth.............. 6
The voice stream-size and voice max-streams values can be adjusted as necessary by using the following command.
config 802.11a cac voice stream-size 84000 max-streams 2
Ensure QoS is setup correctly under the WLAN / SSID configuration, which can be displayed via
“show wlan <WLAN id>”
.
Quality of Service............................... Platinum (voice)
WMM.............................................. Allowed
Dot11-Phone Mode (7920).......................... ap-cac-limit
Wired Protocol................................... 802.1P (Tag=6)
When enabling Call Admission Control on the autonomous access point, the admission must be unblocked on the SSID as well.
It is required to enable Call Admission Control on the SSID configuration, regardless of Admission Control being enabled for
Voice or Video.
Load-based CAC and support for multiple streams are not present on the autonomous access points therefore it is not
recommended to enable CAC on autonomous access points.
The autonomous access point only allows for 1 stream and the stream size is not customizable, therefore SRTP and barge will
not work if CAC is enabled.
dot11 ssid voice
vlan 21
authentication open eap eap_methods
authentication network-eap eap_methods
authentication key-management wpa cckm
admit-traffic
Also ensure that the PHY rate configured on the Cisco Unified Wireless IP Phone 7925G Series is enabled as a nominal rate in
the STREAM configuration of the autonomous access point.
Recommend to use the defaults, where 5.5, 6.0, 11.0, 12.0 and 24.0 Mbps are enabled as nominal rates for 802.11b/g and 6.0,
12.0 and 24.0 Mbps enabled for 802.11a.
If enabling the STREAM feature either directly or via selecting
“Optimized Voice”
for the radio access category in the QoS
configuration section, ensure that only voice packets (RTP) are being put into the voice queue. Signaling packets (SCCP)
should be put into a separate queue. This can be ensured by setting up a QoS policy mapping the DSCP to the correct queue.
For more information about Call Admission Control and QoS, refer to the “Configuring QoS” chapter in the
Cisco IOS
Software Configuration Guide for Cisco Aironet Access Points
at this URL:
http://www.cisco.com/en/US/docs/wireless/access_point/12.3_8_JA/configuration/guide/s38qos.html
