S 4.59 Deactivation of ISDN board functions which are not required

Initiation responsibility: Head of IT Section, IT Security Management

Implementation responsibility: Administrators

A modern ISDN board and its communications software, as well as the operating system in the card's RAM, possess numerous features in addition to pure ISDN functionality. Such "convenience functions", some of which can also be used when the IT system is inactive, include:

• The reception and transmission of faxes

• Functions of a digital answering machine

• Playback of messages recorded on the answering machine

• Telephony via a microphone and earpiece included in the scope of supply of the board

Wherever possible, card functions which are not required should be deactivated, preferably by removing the related software modules. Card functions which can be configured simply through parametrisation must be checked regularly to determine whether the parameter settings are still correct.

Additional controls:

• Are checks made to determine whether available functions are actually required?

• Have functions whose use is obviously not required been disabled?