Backup/Restore authentication control. This variable returns 0 if the call server IP address and telephone's registration password is NOT not included as credentials in an Authentication request-header; 1 (the default) if that data is included and the telephone will accept the server's digital certificate if signed by Avaya, or 2 if that data is included and the telephone will accept the server's digital certificate if signed by Avaya or a trusted certificate based on TRUSTCERTS.