FAS Detection
FAS can occur in multiple ways, the most common is when an answer signal is sent before a call is connected to the far end, this can either cause the user to hear a ringtone or a false audio message on a connected call. Another form of FAS is delayed connect or disconnect, when the destination connection is either delayed at the start of a call or the disconnect from the destination is delayed when they terminate a call. These can result in the billed time being longer than the actual call time or to be billed for a call that never terminates correctly.
