Dialler Guardian

Specifications: The Dialler Guardian (DG420) is a device which connects between the telephone set and the exchange outlet.

Its function is to inhibit connections to the telephone network when unauthorised telephone numbers are dialed when the unit is set up in the Number Barring Mode or permit connections to authorized numbers only when set up in the Number Passing Mode. The two modes are mutually exclusive.

Number Barring Mode: In the Number Barring Mode ALL numbers in a Routing Table Matrix (see below) are barred. If attempt is made to dial a number which is listed in the Routing Table Matrix as a barred number the end-user will receive a long beep from the DG420 guardian forcing the network (telephone line) to disconnect and returning a dialling tone.

Effectively the number is blocked and connection cannot be established with the intended destination. All other numbers not logged in the table are allowed. This mode is specially useful to block international numbers and service numbers with a high cost rate.

Number Passing Mode: In the Number Passing Mode ONLY the numbers listed in the Routing Table Matrix are allowed access to the network. All other numbers not listed are blocked. This mode is intended for use with Personal Computers which need access to the Internet via a dial-up service as it prevents unwanted rogue dialing.

This number of individual phone numbers or services; the old lady who lives on her own but requires access to her son or daughter only for example. In this mode emergency numbers, e. G.999 or 911 are not barred.

The two modes are mutually exclusive, each with its own Routing Table Matrix that can accommodate up to 10 telephone numbers with a maximum of 16 digits each. Also a pre-dial number can be programmed in and it is effective in both modes once programmed. Up to 5 digits can be programmed.

For instance the pre-dialled number,141 Caller ID Withheld number for the UK, can be programmed in, though the units are shipped already pre-programmed.