MSM7xx Controllers Configuration Guide v6.4.0

non-operating channels. The amount of time dedicated for scanning is defined by the settings
you define for Neighborhood scanning.
• Monitor: In this mode, the radio only performs scanning, wireless services are not available.
• Local mesh only and Access point and Local mesh: Scanning is not supported in these modes.
To support the system-wide auto-channel feature, set Channel to Automatic.
To support the system-wide auto-power feature, enable Automatic power control under Transmit
power control.
Neighborhood scanning settings
(Not configurable when Operating mode is set to Access point and Local mesh or Local mesh only.)
These settings let you fine-tune the scanning operation.
Scan ratio
(Not configurable when Operating mode is set to Monitor.)
The percentage of time the radio will spend scanning channels other than the operating channel.
Dwell time
The amount of time (in milliseconds) that a radio remains on a channel while performing channel
scanning. The default value is 30 milliseconds. On the HP 517, the minimum value and default
setting is 32 milliseconds.
• When Operating mode is set to Access point only, specify a value between 20 and 32
milliseconds. (Use a value of 30 milliseconds on the MSM410.)
• When Operating mode is set to Monitor, specify a value between 20 and 1000 milliseconds.
Scanning mode
• Passive: The AP listens to the channel to detect wireless traffic, but does not transmit any
probes. The AP will receive beacon frames and probe response frames, and uses them to
identify neighbors. (When IDS is enabled, other frames are also received and sent to the IDS
system for analysis.) The key point is that no frames are transmitted. This is important for DFS
channels and regulatory-prohibited channels.
• Active: The AP uses probe request frames to speed up neighbor detection. Active scanning
only occurs on channels permitted by the regulatory domain. Transmission of probes is not
allowed on DFS channels, so no probes are sent on DFS channels even when this option is
selected.
Bands to scan
(Not configurable in Monitor mode. The All bands option is automatically used.)
• All bands: Scan both 802.11 bands (2.4 GHz and 5 GHz).
• Operating band only: Scan only the band in which the radio is currently operating.
Recommended settings for single radio APs:
• With IDS disabled, select Operating band only.
• With IDS enabled, select All bands.
Recommended settings for dual radio APs:
• With IDS disabled, configure both radios for Operating band only.
• With IDS enabled, configure the 2.4 GHz radio for Operating band only (with a small scan
ratio), and configure the 5 GHz radio for All bands (with a larger scan ratio). The 2.4 GHz
186 Radio Resource Management