Controller Based WLANs

How does Aruba implement dot11k and how do I configure an 802.11k profile?

Aruba Employee

 

Product and Software: This article applies to all Aruba controllers and ArubaOS 3.4.0.x and later.

The 802.11k protocol provides mechanisms to access points (APs) and clients to dynamically measure the available radio resources. The 802.11K standard provides mechanisms to discover the best available AP, improve handover performance, and ensure seamless continuity of services in a multi-AP environment.

802.11k is intended to improve the way traffic is distributed within a network. In a wireless LAN, each device normally connects to the AP that provides the strongest signal. Depending on the number and geographic locations of the subscribers, this arrangement can lead to excessive demand on one AP and under-utilization of others, which results in degradation of overall network performance. In a network conforming to 802.11k, if the AP with the strongest signal is loaded to its full capacity, a wireless device is connected to one of the underutilized APs. Even though the signal may be weaker, the overall throughput is greater because more efficient use is made of the network resources.

802.11k mechanisms enable WLAN network infrastructure elements and clients to make measured and optimal mobility decisions to ensure QoS for clients. These decisions include:

  • Requesting and reporting radio measurements
  • Performing radio measurements on supported channels
  • Providing information about neighbor APs

In an 802.11k-enabled network, APs and clients can send neighbor reports, beacon reports, and link measurement reports to each other. This allows the APs and clients to take appropriate connection actions.

802.11k is supported in ArubaOS 3.4.0. The following subset is implemented in ArubaOS 3.4.0:

  • Radio Measurement Capability bit
  • Power Constraint Element
  • AP Channel Report Element
  • RRM Enabled Capabilities Element
  • Transmit Power Control Report Element
  • Neighbor Report Request/Response with specified features
  • Beacon Report Request/Response with specified features

o BSS Available Admission Capacity

o Link Measurement Request/Report



 

Configuring an 802.11k Profile Using the GUI

1) Navigate to Configuration > Wireless > AP Configuration. Click either the AP Group or AP Specific tab.

  • If you selected the AP Group tab, click Edit next to the AP group name for which you want to configure the new 802.11K profile.
  • If you selected the AP Specific tab, click Edit next to the AP for which you want to create the 802.11K profile.

 

2) In the Profiles list, expand the Wireless LAN menu, then expand the Virtual AP menu.

 

3) Select the Virtual AP profile for which you want to configure 802.11k settings.

 

4) To edit an existing 802.11k profile, click the 802.11K Profile drop-down list and select the 802.1x profile you want to edit.

-or

To create a new 802.11k profile, click the 802.11K Profile drop-down list and select New. Enter a new 802.11k profile name in the field to the right of the drop-down list. Note that you cannot use spaces in profile names.

5) Configure your desired 802.11k radio settings. This table describes the parameters you can configure in the 802.11k profile.

Parameter

Description

Advertise 802.11K Capability

Select this option to allow virtual APs using this profile to advertise 802.11K capability.

This feature is disabled by default.

Forcefully disassociate
on-hook voice clients

Select this option to allow the AP to forcefully disassociate on-hook voice clients (clients that are not on a call) after a period of inactivity. Without the forced disassociation feature, if an AP has reached its call admission control limits and an on-hook voice client wants to start a new call, that client may be denied. If forced disassociation is enabled, those clients can associate to a neighboring AP that can fulfill their QoS requirements.

This feature is disabled by default.

Measurement Mode for Beacon Reports

Click the Measurement Mode for Beacon Reports drop-down list and specify one of the following measurement modes:

  • active: Enables the active beacon measurement mode. In this mode, the client sends a probe request to the broadcast destination address on all supported channels, sets a measurement duration timer, and, at the end of the measurement duration, compiles all received beacons or probe response with the requested SSID and BSSID into a measurement report.
  • beacon-table: Enables the beacon-table beacon measurement mode. In this mode, the client measures beacons and returns a report with stored beacon information for any supported channel with the requested SSID and BSSID. The client does not perform any additional measurements.
  • passive: Enables the passive beacon measurement mode. In this mode, the client sets a measurement duration timer, and, at the end of the measurement duration, compiles all received beacons or probe response with the requested SSID and BSSID into a measurement report.

Note: If a station does not support the selected measurement mode, it returns a Beacon Measurement Report with the Incapable bit set in the Measurement Report Mode field.

The default beacon measurement mode is beacon-table.

 

6) Click Apply to save your settings.


Configuring an 802.11k Profile Using the CLI

Issue these commands to configure 802.11k profiles. The available parameters for this profile are described in the preceding table.

 

To create or modify existing dot11k profile:


wlan dotllk <profile>
bcn-measurement-mode {active|beacon-table|passive}
clone <profile>
dot11k-enable
force-disassoc

 

To assign dot11k profile to a virtual AP:

 

wlan virtual-ap <profile>
dot11k-profile <profile>

Version history
Revision #:
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Last update:
‎06-30-2014 05:33 PM
Updated by:
 
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