[USR-TC] RADIUS Failover

Does anyone know if there is a way to configure HiperARC equipment to authenticate dialup users to RADIUS, but if RADIUS timeouts it skips authentication and begins PPP? While we can manually 'Set Modem_Group all disable_authentication ppp' when RADIUS fails, we would like it to fall-through automatically if possible. Thus if RADIUS fails (times out) it allows any dialup user online without authentication. Currently if RADIUS timeouts it errors, typically resulting in an error 718 on the client. Any thoughts or suggestions would be appreciated. -- Adam Barnhill