User's Guide

18 Passive tests 52
7signal Ltd, Panuntie 6, FI-00620 HELSINKI, FINLAND, [phone], [e-mail], www.7signal.com
7signal Sapphire Carat Carat User Guide Release 3.0
18 PASSIVE TESTS
18.1 Initial network scan
When the Eye has been installed or needs to be reset, you must run a network scan. There are
various preconfigured scanning durations. When an Eye has been installed for the first time, it
is recommended that you run the longest scan, titled “Initial scan.” The purpose of the initial
scan is to scan the monitoring station’s radio frequency environment very thoroughly and to
detect the access points suitable for monitoring.
Network scan type
Description
Estimated duration (all antennas and
channels) for channels 1-11 excl. 5 GHz
Initial
First deployment
15–20 min
Slow
Thorough
7–9 min
Regular
Normal
3–4 min
Fast
Quick
less than 1 min
The scan results are presented in a table. An initial scan should be run whenever substantial
physical changes have been made in the environment being monitored (for example, new or
removed walls), or if the Eye’s location has been changed.
The table contains the following information about the WLAN access points detected:
• Network name (ESSID)
• Encryption methods supported by the access point
• MAC address of the access point
• Channel
• Management status (if not known, denoted as “Unknown”)
• Antenna that hears the access point best
• Access point signal strength
• Noise level
The access points in the service area must have a management status. Setting a management
status means that the access point’s existence is acknowledged. Unacknowledged access
points prompt issuing of an alarm if such an alarm has been configured. The management
statuses are as follows:
• Managed: Monitored by this monitoring station
o The recommendation for signal strength is >65 dBm
• Own: Own access point managed by another monitoring station
• Known: An access point that is an accepted part of the radio frequency environment
(for example, a neighboring network)
o If possible, ensure the access point operates properly and can be accepted
• Unknown: An access point without a monitoring status
o In practice, this status should exist only during network scans in new service
areas; it should not exist in normal use
The changes are saved in Sapphire Carat’s database and the installed monitoring station. The
test is described in more detail below, under the “Network Scan” description.