Product and Software: This article applies to all Aruba controllers and ArubaOS versions.
The Ekahau inventory tag is a wireless device that transmits location information of what it is attached to based on the signal strength or beacon strength of surrounding access points. These tags are usually 802.11b/g compatible. Aruba controllers are able to handle either type of setup through custom configuration parameters. Although these tags are 802.11b/g compliant, some of their behavior does not conform to best practices for wireless client devices.
The Ekahau tags are made to send location information every 30 seconds while sitting still or every 5 seconds while moving. They have the ability to sense when they have been moved in any direction. Their process is to awaken, associate, authenticate (if authentication is being used), send their payload via UDP without delivery confirmation, deauthenticate, disassociate, and then go back to sleep. Their sleep mode should not be confused with power save mode. When the Ekahau tags go to sleep, they turn off their 802.11 radio completely. This entire process can take less than 5 seconds in most cases.
This process can create an issue with the ability of the Aruba controllers to handle the frequent associate and disassociate requests as it relates to the flushing of the association table. Therefore, certain configuration changes are needed to maintain the overall stability of your wireless network.
The first configuration change that is needed is to turn on DoS Prevention in the VAP profile that is in use for the Ekahau clients.
The second change that must be made is to the Station Ageout Time, which is located in the SSID profile. It must be increased from the default 1000 seconds to 5000 seconds.
These changes must be made for the controller to maintain the association table for the Ekahau tags instead of them being explicitly removed per the disassociation request. These changes will allow for a smoother operation the Ekahau tags with less impedance on other 802.11 clients on the wireless network.