Call Admission Control - Cisco 7925G Deployment Manual

Call Admission Control

You have the option to configure inbound and outbound call admission control on the access point:
•
Enable Call Admission Control / Wi-Fi MultiMedia Traffic Specifications (TSPEC)
•
Set the desired maximum RF bandwidth that is allocated for voice traffic (default = 75%)
•
Set the bandwidth that is reserved for roaming clients (default = 6%)
You can modify the minimum PHY rate for the phone to use when Call Admission Control (CAC) is enabled.
•
Enable a data rate that is enabled on the access point. (Default setting is 12 Mbps)
•
Cisco Access Points will only accept a minimum PHY rate of 5.5, 6, 11, 12 or 24 Mbps, so ensure that one of these
rates are enabled.
As of the 1.3(3) release, the Cisco Unified Wireless IP Phone 7925G will auto-negotiate the minimum PHY rate to be used for
TSPEC. By default it will try the locally configured minimum PHY rate (i.e. 12 Mbps) first, but if that data rate is not enabled
on the access point, then it will try the next highest enabled data rate on the access point. If there is not a higher data rate
enabled, then it will then try the next lowest data rate as the minimum PHY rate.
In releases prior to 1.3(3), the Cisco Unified Wireless IP Phone 7925G would use the static minimum PHY rate configured
locally.
If 12 Mbps is not enabled on the access point, you must ensure that the next highest data rate is 24 Mbps (which is supported).
For example, if 12 Mbps is disabled but 18 Mbps is enabled, the phone will try the next highest rate of 18 Mbps and fail
because that minimum PHY rate for CAC is not supported by the Cisco access point.
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