Cisco Unified Wireless IP Phone 7925G Series Deployment Guide
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Sample Voice Packet Capture
This packet capture below shows that RTP packets bound for the Cisco Unified IP Phone 7925G over the air should be marked
with DSCP = EF and UP = 6.
Call Admission Control
Inbound and outbound call admission control can be enabled on the access point.
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Enable Call Admission Control / Wi-Fi MultiMedia Traffic Specifications (TSPEC)
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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%)
The minimum PHY rate can be configured for which the phone is to use when Call Admission Control (CAC) is enabled.
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Enable a data rate that is enabled on the access point. (Default setting is 12 Mbps)
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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 Series 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.