Cisco Cisco Aironet 350 Wireless LAN Client Adapter

Some applications that run on a client device may require fast roaming between access points. Voice 
applications, for example, require seamless roaming to prevent delays and gaps in conversation. Support 
for fast roaming is available for LEAP-enabled clients in Install Wizard version 1.1 or later.

During normal operation, LEAP-enabled clients mutually authenticate with a new access point by 
performing a complete LEAP authentication, including communication with the main RADIUS server. 
However, when you configure your wireless LAN for fast roaming, LEAP-enabled clients securely roam 
from one access point to another without the need to reauthenticate with the RADIUS server. Using 
Cisco Centralized Key Management (CCKM), an access point that is configured for wireless domain 
services (WDS) uses a fast rekeying technique that enables client devices to roam from one access point 
to another in under 150 milliseconds (ms). Fast roaming ensures that there is no perceptible delay in 
time-sensitive applications such as wireless Voice over IP (VoIP), enterprise resource planning (ERP), 
or Citrix-based solutions.

This feature is enabled on the client adapter in two different ways, depending on the software installed:

If you are using client adapter firmware version 5.30.xx (which is included in Install Wizard version 
1.2), you need to enable fast roaming in ACAT or the Aironet Client Utility (ACU) version 6.2.

If you are using client adapter firmware version 5.20.17 (which is included in Install Wizard version 
1.1), fast roaming is supported automatically.

Regardless of how fast roaming is enabled on the client adapter, it must also be enabled on the access 
point.

Access points must use Cisco IOS Release 12.2(11)JA or greater to enable fast roaming. Refer to the 
documentation for your access point for instructions on enabling this feature.

If the Microsoft 802.1X supplicant is installed on your computer, you must disable one or two Windows 
parameters in order for this feature to operate correctly. 

Selecting this feature causes the client adapter to look for a better access point if the signal strength of 
its associated access point is less than the specified value after the specified time and to switch 
associations if it finds one.

Example: If the default values of 20 seconds and 50% are used, the client adapter begins monitoring the 

strength of the signal received from its associated access point 20 seconds after becoming 
associated. The monitoring continues once per second. If the client detects a signal strength 
reading below 50%, it scans for a better access point.