Up to version 10.1 2X Remote Application Server supported 2nd Level Authentication with either Deepnet Authentication Server or Safenet Server. Both providers were implemented using the APIs provided by the authentication server. This gave better integration where features like Zero Managment Software tokens were possible to implement, however there was the need to integrate with a generic 2nd Level authentication server.
This will be available in version 10.5 where 2X Remote Application Server will support 2nd Level Authentication via any Radius server.
The Radius server can support multiple levels of authentication and also offer challenges. By using challenges it is possible to configure more than two levels of authentication making the system more secure.
When 2nd Level authentication was introduced in 2X Remote Application Server, the system was designed to support different 2nd level authentication providers. This made it possible to add support for radius by changing only the Publishing Agent. No changes were necessary on the clients.