User Manual Part 4

Administration Tab
SpectraGuard® Enterprise User Guide
187
Sensor Timeout: The sensor sends keep alive information to the server at a regular time interval specified
here, to tell the server that it is alive. If the system does not receive this keep alive information for a time
span specified here, it declares the sensor inactive.
Note: Sensor timeout is not user configurable for this release and has been fixed as 600 seconds.
RF Signal Computation Constants
Moving Average Constant: A constant used to find the weighted average of signal strength as seen by a
sensor for a transmitter. Higher value gives more weight to more recently seen signal strength values.
(Minimum: 0; Maximum: 1; Default: 0.05)
sensor observes signal strengths as RSSI reported by the driver. The system converts this information to dBm values
for further use. The conversion formula for this is different for 2.4 GHz and 5 GHz frequency spectrum. The formula
is dBm = RSSI + dBm Conversion Constant.
RSSI <-> dBm Conversion Constant for 802.11a: This value used for 5 GHz band is set to -98.
RSSI <-> dBm Conversion Constant for 802.11b/g: This value used for 2.4 GHz band is set to -90.
Sensor Server Communication
Frequency of Device Updates: The system is informed immediately when device attributes change or when a
device is first detected. If no such changes take place, the system should still be informed about the device
updates. Here you can set that time after which the system is notified of the updates.
(Minimum: 1 day; Maximum: 365 days; Default: 36 days)
Frequency of Signal Strength Updates: The system should be periodically informed about the signal strength
updates. Here you can set that time after which the system is notified.
(Minimum: 1 minute; Maximum: 5 minutes; Default: 2 minutes)
Records Constants (per Sensor): A sensor maintains records for APs, Clients, and associations. The constants
below define the maximum number of APs, Clients, and associations for which to maintain records with the
sensor(s).
Maximum Number of AP records to keep: Specifies the maximum number of APs for which to maintain
records with the sensor(s).
(Minimum: 100; Maximum: 500; Default: 128)
Maximum Number of Client records to keep: Specifies the maximum number of Clients for which to
maintain records are with the sensor(s).
(Minimum: 100; Maximum: 500; Default: 256)
Maximum Number of Association records to keep: Specifies the maximum number of associations for which to
maintain records with the sensor(s).
(Minimum: 100; Maximum: 500; Default: 128)
Discovery
Sensors and NDs inject discovery (ARP) broadcast packets in bursts on the network at regular intervals. These
packets detect the presence of wireless devices connected to the network. If there are multiple sensors and NDs on a
subnet, only one injects discovery packets on the subnet.