Abstract: A correspondence table is stored in a mobile switching center. In the correspondence table, at least one local area code for a geographical subarea is assigned to each authorization organization number of an authorization organization. Furthermore, a supervision file is stored in which a mobile subscriber number is entered for a mobile subscriber who is to be monitored. When an attempt is made to set up a connection from/to the mobile subscriber, the correspondence table is used to determine whether respective authorization organizations are authorized to monitor the communications link in the geographical subarea in which the mobile subscriber is located. A configuration for monitoring communications links is also provided.