S 4.36 Blocking fax recipient numbers

Initiation responsibility: Superiors, IT Security Management

Implementation responsibility: Fax Officer

Currently, there are at least three methods of preventing the accidental or intentional transmission of information or documents via fax to undesired recipient numbers:

Some devices allow the (positive) exclusion of certain recipient numbers or (negative) exclusion of all recipient numbers except certain selected ones from fax communication.

The same type of authorisation can be realised in modern PBX systems, provided that the fax machine is connected to the telephone network via such a system.

If a fax machine or PBX does not offer such a possibility, one alternative is to rent an auxiliary device from the operator of the public network which prevents the establishment of a connection with certain subscriber numbers (positive and negative exclusion).

Additional controls:

• Is there a requirement for blocking certain fax recipients?

• Have fax messages been sent to a wrong recipient on any occasion?