Implementation responsibility: Site technical service, purchase department
This measure is to be observed for the procurement of new answering machines. If existing devices do not meet security requirements, their disposal and the procurement of new ones is to be considered.
To reduce threats to a minimum, the following criteria should be observed during the purchase of answering machines, taking their price/performance ratio into consideration:
The devices must be authorised by the Federal Post in order to ensure trouble-free telecommunication.
In the case of devices with a fully or partially digital memory, it is recommended to select those which are equipped with an emergency power supply consisting of a battery pack or removable accumulator. Permanently integrated accumulators need to be replaced by a service technician, and this procedure entails longer deactivation periods for the answering machine.
Due to variations in the quality of message recording (e.g. by analogue or digital units), the performance of answering machines in this context should be checked before purchase.
Devices with a fully or partially digital memory should be equipped with a display for indicating the battery charge and a distinct warning signal (if possible, acoustic) for timely indication of low battery charges.
Answering machines which use a single cassette for incoming as well as outgoing messages require longer waiting periods for tape winding. The acceptability of this extra time should be weighed.
The user-friendliness of answering machines should be evaluated. Ergonomic and clearly arranged buttons, single-function keys and easily understandable manuals are advantageous in this respect.
If possible, the remote-inquiry unit should have a mechanical or electronic deactivation function, and the security code should consist of at least three or four digits and be freely programmable. Increased security is offered by a disabling circuit which interrupts the connection to the answering machine after three invalid entries of the security code. This at least increases the time required by would-be perpetrators and the telephone charge incurred by them. An even greater advantage is offered by devices which completely disable the remote-inquiry function after three invalid attempts and only allow this function to be restored on the answering machine itself. The prolongation of the disablement periods after each successive invalid entry is also advantageous.
Additional controls:
Is the purchasing department aware of the above-mentioned instructions?
