Problem:
In highly congested or high dense deployment we might have observed high channel utilization in 5 GHz radio of an AP-130 Series access point in client association and throughput issues. In order to over come this situation starting from ArubaOS 6.4.2.10, the Spur Immunity feature got introduced.
Diagnostics:Starting from ArubaOS 6.4.2.10, the Spur Immunity setting is introduced. Configure this setting if high channel utilization is observed in the 5 GHz radio of an AP-130 Series access point in a noise-free environment resulting in client association and throughput issues. This setting appears in the controller WebUI only if the AP model is AP-130 Series.
Spur Immunity for 5 GHz radio. This feature fine-tunes the Cyclic Power Threshold (CPT) of a 5 GHz radio. The value specified here is the offset from the base value of 2 dB (for example, setting the CPT value to 1 corresponds to 2 + 1 = 3 dB. Similarly, setting the CPT value to 10 corresponds to 2+10 = 12 dB).
SolutionWe can configure this setting using the controller WebUI or CLI.
In the WebUI
Log in to the controller WebUI and follow the instructions below.
1. Navigate to the Configuration > WIRELESS > AP Configuration page.
2. In the AP Group tab, click the desired profile.
3. In the Profiles list, navigate to the RF Management > 802.11a radio profile menu.
4. In the Advanced tab of the Profile Details section, configure the Spur Immunity setting.
In the CLI
A new spur-immunity parameter can be configured, the 5 GHz spur immunity in the controller CLI as well is introduced in the rf dot11a-radio-profile command.
rf dot11a-radio-profile
spur-immunity
Use this parameter when high channel utilization is observed in the 5 GHz radio of AP-130 Series access points in a noise-free environment causing client association or throughput issues.
Adjust the CPT value to eliminate the spur impacts. Range definition is as follows:
l 0: default CPT
l 1-19: CPT growth from default (3 dB to 21 dB)
l 20: Setting this parameter to 20 sets the cell-size-reduction value to 1. Cell-size-reduction is the receive coverage area of the AP.
NOTE: Configure this parameter under the supervision of Aruba Technical Support.
NOTE: Setting the spur immunity to a higher value may decrease the AP RF coverage.
NOTE: This parameter is applicable for AP-130 Series access points only. The controller ignores this parameter if configured for non-AP-130 Series access points.
Range: 0-20 CPT, Default: o CPT
Wecan verify the configured value by executing the show rf dot11a-radio-profile command.
show rf dot11a-radio-profile
Example:
The following example displays the spur immunity value for an 802.11a radio.
(host) #show rf dot11a-radio-profile default
802.11a radio profile "default"
-------------------------------
Parameter Value
--------- -----
Radio enable Enabled
Mode ap-mode
High throughput enable (radio) Enabled
Very high throughput enable (radio) Enabled
Channel 36
Transmit EIRP 15 dBm
Non-Wi-Fi Interference Immunity 2
Spur Immunity 0
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