Dfs In Map - Cisco Mesh Access Points Deployment Manual

Troubleshooting

DFS in MAP

The MAP performs the following steps as a response to radar detection:
1 The MAP sends a radar seen indication to the parent and ultimately to the RAP indicating that the channel
is infected. The RAP sends this message to the controller. The message appears to be coming from the
RAP. The MAP, RAP, and controller mark the channel as infected for 30 minutes.
2 The MAP blocks the channel for 30 minutes. This 30-minute period is called the nonoccupancy period.
3 The controller sends a TRAP, which indicates that the radar has been detected on the channel. The TRAP
remains until the nonoccupancy period expires.
4 The MAP has 10 seconds to move away from the channel. This is called the channel move time, which is
defined as the time for the system to clear the channel and is measured from the end of the radar burst to
the end of the final transmission on the channel.
5 The MAP enters the quiet mode. In the quiet mode, the MAP stops data transmissions. Beacons are still
generated and probe responses are still delivered. The quiet mode exists until the channel move time is
over (10 seconds).
6 The controller picks up a new random channel and sends the channel to the RAP.
7 The RAP receives the new channel information and sends channel change frames (unicast, encrypted) to
a MAP, and each MAP sends the same information to its lower children down the sector. Each mesh access
point sends the channel change frames once every 100 msecs for a total of five times.
8 Each mesh access point tunes to the new channel and enters into the silent mode. During the silent mode,
only the receiver is ON. There is no packet transmission. An AP keeps scanning the new channel for any
radar presence for 60 seconds. This process is called the channel availability check (CAC). The MAP
should not disconnect from the controller. The network should remain stable during this one-minute period.
DFS functionality allows a MAP that detects a radar signal to transmit that up to the RAP, which then acts as
if it has experienced radar and moves the sector. This process is called the coordinated channel change. This
functionally can be turned on or off on the controller. The coordinated channel change is enabled by default.
To enable DFS, enter the following command:
(Cisco Controller) >
To verify that DFS is enabled on the network, enter the following command:
(Cisco Controller) >
A MAP that detects radar should send a message to the RAP, unless the parent has a different BGN, in
Note
which case it does not send messages for a coordinated sector change. Instead, the MAP reenters the
SCAN state and searches on nonradar seen channels for a new parent.
Note Ensure that none of your mesh access points are using a default BGN.
OL-27593-01
config mesh full-sector-dfs enable
show network summary
Cisco Mesh Access Points, Design and Deployment Guide, Release 7.3
Dynamic Frequency Selection
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