Cisco Cisco IP Phone 8841 Guía De Diseño
Cisco Wireless IP Phone 8821 and 8821-EX Wireless LAN Deployment Guide
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802.11 Network
Use the following guidelines to assist with deploying and configuring the wireless LAN.
5 GHz (802.11a/n/ac)
5 GHz is the recommended frequency band to utilize for operation of the Cisco Wireless IP Phone 8821 and 8821-EX.
In general, it is recommended for access points to utilize automatic channel selection instead of manually assigning channels to
access points.
If there is an intermittent interferer, then the access point or access points serving that area may need to have a channel statically
assigned.
The Cisco Wireless IP Phone 8821 and 8821-EX support Dynamic Frequency Selection (DFS) and Transmit Power Control
(TPC) from 802.11h, which are required when using channels operating at 5.260 - 5.720 GHz, which are 15 of the 24 possible
channels.
Need to ensure there is at least 20 percent overlap with adjacent channels when deploying the Cisco Wireless IP Phone 8821
and 8821-EX in an 802.11a/n/ac environment, which allows for seamless roaming. For critical areas, it is recommended to
increase the overlap (30% or more) to ensure that there can be at least 2 access points available with -67 dBm or better, while
the Cisco Wireless IP Phone 8821 and 8821-EX also meet the access point’s receiver sensitivity (required signal level for the
current data rate).
In general, it is recommended for access points to utilize automatic channel selection instead of manually assigning channels to
access points.
If there is an intermittent interferer, then the access point or access points serving that area may need to have a channel statically
assigned.
The Cisco Wireless IP Phone 8821 and 8821-EX support Dynamic Frequency Selection (DFS) and Transmit Power Control
(TPC) from 802.11h, which are required when using channels operating at 5.260 - 5.720 GHz, which are 15 of the 24 possible
channels.
Need to ensure there is at least 20 percent overlap with adjacent channels when deploying the Cisco Wireless IP Phone 8821
and 8821-EX in an 802.11a/n/ac environment, which allows for seamless roaming. For critical areas, it is recommended to
increase the overlap (30% or more) to ensure that there can be at least 2 access points available with -67 dBm or better, while
the Cisco Wireless IP Phone 8821 and 8821-EX also meet the access point’s receiver sensitivity (required signal level for the
current data rate).
Dynamic Frequency Selection (DFS)
DFS dynamically instructs a transmitter to switch to another channel whenever radar signal is detected. If the access point
detects radar, the radio on the access point goes on hold for at least 60 seconds while the access point passively scans for
another usable channel.
detects radar, the radio on the access point goes on hold for at least 60 seconds while the access point passively scans for
another usable channel.