This optional parameter allows you to control which RADIUS attribute is used to look up the user database. Normally, Radiator uses the User-Name RADIUS attribute as the key to find a user in the user database. If the AuthenticateAttribute parameter is defined, it specifies the name of an alternative RADIUS attribute that will be used as the key during the lookup in the user database. This is useful in order to do authentication based on, say, the Calling-Station-Id:

# look up database based on Calling-Station-Id
AuthenticateAttribute Calling-Station-Id