If you do not manage TTI carefully, unauthorized use of this feature can cause you security problems. For example, someone who knows the TTI security code can disrupt normal business functions by separating telephones or data terminals. You can help protect against unauthorized use of TTI by frequently changing the TTI security code. To further enhance system security, remove the Feature Access Code (FAC) from the system when the FAC is not needed. Consult the Avaya Products Security Handbook for additional information to secure your system, and to find out about regularly obtaining updated security information.