Wireless/Redundant Edge Services xl Module Management and Configuration Guide WS.01.03 or greater

6-21
Wireless Network Management
AP Detection
2. Check the Enable box in the AP Detection section.
3. If you so desire, customize settings. You can:
• Increase the size of the list for detected APs by entering a value
between 1 and 1000 in the Maximum detected APs field.
This value controls the number of APs about which the module will
store information in the approved APs list and in the unapproved APs
list. The two lists are considered separately. For example, by default
the module can store 100 approved APs and 100 unapproved APs.
In a very large network, or in an environment with a great deal of
wireless activity, the module’s database might require more than 100
entries.
Another reason that lists might require more entries is that the Unseen
AP timeout is high.
• Specify how long the module will store information about an AP that
is no longer detected. Enter a time between 1 and 65535 seconds
(roughly 18 hours) in the Unseen AP timeout field. The default is 300
seconds (five minutes).
4. Click the Apply button.
When you enable AP detection, each adopted RP radio listens for beacons
from other APs operating on its own channel. When a radio hears such a
beacon, it forwards information in the beacon to the Wireless Edge Services
xl Module.
Dedicating Radios as Detectors
As indicated above, RPs typically implement AP detection as passive listening.
While sending and receiving traffic from associated wireless stations, they
also listen for beacons from other APs.
However, the Wireless Edge Services xl Module can also configure an RP (or
more precisely, an RP radio) to constantly scan for neighboring APs. Such a
radio is called a detector, and it cannot connect to wireless stations. A detector
uses auto channel select (ACS) to change to and scan all channels that are:
■ in its frequency (either 802.11a’s 5 GHz or 802.11bg’s 2.4 GHz)
■ allowed by its country’s regulations
Table 6-1 and Figure 6-14 compare normal and detector RP radios.