Cisco Cisco Aironet 1200 Access Point
9
Release Notes for Cisco Aironet Access Points for Cisco IOS Release 12.3(8)JEC
OL-14518-01
Important Notes
Access Point Creates File When Radar is Detected on a DFS Channel
When an access point detects a radar on a DFS channel, the access point creates a file in its flash memory.
The file is based on the 802.11a radio serial number and contains the channel numbers on which the the
radar is detected. This is an exepected behavior and you should not remove this file. See the caveat
CSCsv36602 in the
The file is based on the 802.11a radio serial number and contains the channel numbers on which the the
radar is detected. This is an exepected behavior and you should not remove this file. See the caveat
CSCsv36602 in the
.
Access Points Send Multicast and Management Frames at Highest Basic Rate
Access points running recent Cisco IOS versions are transmitting multicast and management frames at
the highest configured basic rate, and is a situation that could causes reliability problems.
the highest configured basic rate, and is a situation that could causes reliability problems.
Access points running LWAPP or autonomous IOS should transmit multicast and management frames at
the lowest configured basic rate. This is necessary in order to provide for good coverage at the cell's
edge, especially for unacknowledged multicast transmissions where multicast wireless transmissions
may fail to be received.
the lowest configured basic rate. This is necessary in order to provide for good coverage at the cell's
edge, especially for unacknowledged multicast transmissions where multicast wireless transmissions
may fail to be received.
Since multicast frames are not retransmitted at the MAC layer, stations at the edge of the cell may fail
to receive them successfully. If reliable reception is a goal, then multicasts should be transmitted at a
low data rate. If support for high data rate multicasts is required, then it may be useful to shrink the cell
size and to disable all lower data rates.
to receive them successfully. If reliable reception is a goal, then multicasts should be transmitted at a
low data rate. If support for high data rate multicasts is required, then it may be useful to shrink the cell
size and to disable all lower data rates.
Depending on your specific requirements, you can take the following action:
•
If you need to transmit the multicast data with the greatest reliability and if there is no need for great
multicast bandwidth, then configure a single basic rate, one that is low enough to reach the edges of
the wireless cells
multicast bandwidth, then configure a single basic rate, one that is low enough to reach the edges of
the wireless cells
•
If you need to transmit the multicast data at a certain data rate in order to achieve a certain
throughput, then configure that rate as the highest basic rate. You can also set a lower basic rate for
coverage of non-multicast clients.
throughput, then configure that rate as the highest basic rate. You can also set a lower basic rate for
coverage of non-multicast clients.
Layer 3 Not supported with NAC for MBSSID
Layer 3 is not supported with NAC for MBSSID in this release.
DFS Enabled by Default on 5-GHz Radios in North America
In this release, Dynamic Frequency Selection (DFS) is automatically enabled on 5-GHz radios
configured for use in North America. The 5-GHz radios use DFS to detect radar signals and avoid
interfering with them. Radios configured for use in Europe and Singapore also use DFS. Other regulatory
domains do not use DFS. Refer to the
configured for use in North America. The 5-GHz radios use DFS to detect radar signals and avoid
interfering with them. Radios configured for use in Europe and Singapore also use DFS. Other regulatory
domains do not use DFS. Refer to the
for detailed information.