Cisco Unified IP Phone 9971 Wireless LAN Deployment Guide
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Note:
Currently no Call Admission Control support for video.
Dynamic Transmit Power Control (DTPC)
To ensure packets are exchanged successfully between the Cisco Unified IP Phone 9971 and the access point, Dynamic
Transmit Power Control (DTPC) should be enabled.
DTPC prevents one-way audio when RF traffic is heard in one direction only.
If the access point does not support DTPC, then the Cisco Unified IP Phone 9971 will use the highest available transmit power
depending on the current channel and data rate.
When using an access point that supports DTPC, set the client power to match the local access point power.
Do not use default setting of
Max
power for client power on Cisco Autonomous Access Points as that will not advertise DTPC
to the client.
The access point’s radio transmit power should not have a transmit power greater than what the Cisco Unified IP Phone 9971
can support.
Rugged Environments
When deploying the Cisco Unified IP Phone 9971 in a rugged environment (e.g. manufacturing, warehouse, retail), additional
tuning on top of the standard design recommendations may be necessary.
Below are the key items to focus on when deploying a wireless LAN in a rugged environment.
Access Point and Antenna Selection
For rugged environments, it is recommended to select an access point platform that requires external antennas (e.g. Cisco
1602e, 2602e, 3502e, 3602e, and 3702e Series Access Points). It is also important to ensure an antenna type is selected
which can operate well in rugged environments.
Access Point Placement
It is crucial that line of sight to the access point’s antennas is maximized by minimizing any obstructions between the Cisco
Unified IP Phone 9971 and the access point. Ensure that the access point and/or antennas are not mounted behind any
obstruction or on or near a metal or glass surface.
If access points with integrated antennas (e.g. Cisco 1040, 1130, 1140, 1602i, 2602i, 3502i, 3602i, and 3702i Series Access
Points) are to be used in some areas, then it is recommended to mount those access points on the ceiling as they have omni-
directional antennas and are not designed to be patches.
Frequency Band
As always, it is recommended to use 5 GHz. Use of 2.4 GHz, especially when 802.11b rates are enabled, may not work
well.
For the 5 GHz channel set, it is recommended to use a 8 or 12 channel plan only; disable UNII-2 extended channels if
possible.
Data Rates
The standard recommended data rate set of 12-54 Mbps may not work well if multipath is present at an elevated level.
Therefore, it is recommended to enable lower data rates (e.g. 6 Mbps) to operate better in such an environment.
If 5 GHz is used for VoWLAN only, then it is also recommended to disable data rates above 24 Mbps (i.e. 36, 48, 54 Mbps)
to increase first transmission success (e.g. 6 as mandatory, 12 and 24 as supported). If 5 GHz is also used for data, video or
other applications, then is suggested to keep the higher data rates enabled (e.g. 6 as mandatory, 9, 12-54 as supported).
Summary of Contents for UNIFIED 9971
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