3com WXR100 3CRWXR10095A User Manual

When a wireless client successfully roams from one MAP to another, its 
sessions are affected in the following ways:

„

The WX treats this client session as a roaming session and not a new 
session.

„

RADIUS accounting is handled as a continuation of an existing session, 
rather than a new one.

„

The session with the roamed-from MAP is cleared from the WX, even 
if the client does not explicitly disassociate from the MAP and the IEEE 
802.1X reauthentication period has not expired.

Roaming requires certain conditions and can be affected by some of the 
WX switch’s timers. You can monitor a wireless client’s roaming sessions 
with the display sessions network verbose command.

For roaming to take place, the roaming client must associate or 
reassociate with a MAP in the Mobility Domain after leaving an existing 
session on a different MAP in the Mobility Domain in one of the following 
states: 

„

ACTIVE — The normal state for a client that has left radio range 
without sending a request to disassociate.

„

DEASSOCIATED — The state of a client that has sent an 802.11 
disassociate message, but has not roamed or aged out yet.

In addition, the following conditions must exist for roaming to succeed: 

„

Mobility Domain communications must be stable. 

Generally, the communications required for roaming are the same as 
those required for VLAN tunneling. A client can also roam among 
ports on a WX when a Mobility Domain is inaccessible or not 
configured.

„

Client authentication and authorization on the roamed-to MAP must 
be successful on the first attempt. 

If authentication or authorization fails, MSS clears the client session. Depending 
on when the failure occurs, roaming can be disqualified or delayed.

„

The client must use the same authorization parameters for the 
roamed-to MAP as for the roamed-from MAP. 

If the client changes its encryption type or VLAN name, MSS might 
record a new session rather than a roamed session.