1.2 Making CallsUser Manual 43• WARNINGThere is a risk that fraudulent telephone calls will be made using the Outside-to-Outside (CO-to-CO) Line Call feature of DISA.The cost of such calls will be billed to the owner/renter of the PBX.To protect the PBX from this kind of fraudulent use, we strongly recommend:a) Enabling DISA security (Trunk Security or All Security).b) Keeping DISA security codes secret.c) Selecting complex, random codes that cannot be easily guessed.d) Changing codes regularly.• If you dial 4 digits or more when dialling an extension number, the call will be disconnected.When you dial an invalid extension number of 3 digits or less, the call is redirected to thepreprogrammed intercept destinations or disconnected, according to systemprogramming.• CO-to-CO Line Call DurationThe length of outside-to-outside (CO-to-CO) line calls may be limited through systemprogramming.Both the outside caller and the outside destination will hear a warning tone 15 secondsbefore a specified time limit. When the timer expires, the call is disconnected.• If the DISA Automated Attendant (AA) service is used, you can access the desired partysimply by pressing a preprogrammed single-digit number (DISA AA number) while or afterhearing a DISA OGM or after a short beep. AA menus can be up to 3 levels deep.• If you enter an invalid security code 3 times consecutively, the call will be disconnectedautomatically. If you enter a DISA security code a second and third time, dialling " " is notnecessary.Customising Your System• 3.3.2 System Programming—DISA Security Code [512]
