False Answer Supervision
False Answer Supervision (FAS) describes a criminal offense in telephone switching technology in which an A-subscriber is billed for the costs of a successfully established call, even though the desired connection to the B-subscriber did not actually come about.
FAS is usually installed deliberately in order to be able to draw termination charges despite the service not being provided. In fact, it is a fraud crime .
In the specific FAS case, the connection setup is sabotaged and rerouted so that call signaling does not take place at the B-subscriber. Instead, after dialing the destination number, voices or tones - usually from a tape - are played to the A-subscriber, which are intended to keep him from ending the connection for as long as possible. This can be room background noise (human voices), for example. Often only a ring tone is played from the tape in order to make the caller believe that the B-subscriber's device is ringing.
Automatic detection of FAS by the subscriber network operator is difficult or even impossible, since methods would have to be used for this purpose which would in particular violate the secrecy of telecommunications .
Therefore, the subscriber network operator is usually dependent on specific information from the A-subscriber in order to switch off the FAS or to have it switched off.
See also
Individual evidence
- ↑ Explanation of FAS terms (website of Tata Communications), accessed on October 19, 2011. ( Memento of June 3, 2013 in the Internet Archive )
- ↑ Brief description of FAS. Archived from the original on July 20, 2010 ; accessed on December 23, 2012 (English).
