Cisco

Aironet Extensions - A proprietary feature implemented by Cisco

Aironet Extensions make additional information about the Access Points available, including but not limited to:

• Device Name
• Device Type
• Radio Type - used to determine certain characteristics about the radio, such as data rate, radio type (1310, 1200, 352 or 342), security type (WEP/802.1x), etc.
• Current Access Point load
• Number of associated clients

Devices that are CCX compatible also can take advantage of some of the Aironet Extension features.

• Text Source: Cisco Aironet Access Point FAQ
• Aironet Extensions Further Reading: cciew.blogspot.co.uk

Additional Note:

Although Aironet Extensions is enabled by default, best practice guides suggest disabling this feature unless CCX compatible devices are on your WLAN.

(Thank you to Scott Stapleton)