NPS: Override User-Name
Applies To: Windows Server 2008, Windows Server 2008 R2
You can use this registry setting when you deploy Routing and Remote Access service (RRAS) as a dial-up server and you want to use the calling number as the user identity.
Incorrectly editing the registry might severely damage your system. Before making changes to the registry, you should back up any valued data on the computer.
To always use the calling number as the user identity, set the value of the Override User-Name registry entry to 1 on the authenticating server.
If you set Override User-Name to 1 and the User Identity Attribute to 31, the authenticating server can perform only Automatic Number Identification/Calling Line Identification (ANI/CLI)-based authentication. Normal authentication by using authentication protocols, such as Microsoft Challenge Handshake Authentication Protocol (MS-CHAP) and Extensible Authentication Protocol (EAP), is disabled.