发明授权
US5943393A Telecommunications intercept system 失效
电讯拦截系统

Telecommunications intercept system
摘要:
A telephone wiretapping system having a call-forward event and reporting processor for producing a call-forward event control signal when a call from a calling party to a predetermined telephone line is to be call-forwarded to a different telephone line. A switch is responsive to the control signal produced by the call forward event and reporting system for switching the recording device from the target telephone line to the call-forward event and reporting processor when the control signal indicates a call-forwarding event. With such an arrangement, the recording device will recorded calling event signals to, or from, the target telephone line even though the calling event signals are occurring at the call-forwarded telephone line. The call-forward event and reporting processor produces signalling information taking place between the telephone line of the calling party and the telephone line of the different, call-forwarded telephone line. The switch couples the signalling information taking place between the telephone line of the calling party and the telephone line of the different, call-forwarded telephone line produced by the call-forward event and reporting processor to the recording device when the call-forward event control signal is produced. A tone generator is coupled between the switch and the call-forward event and reporting processor for producing a predetermined tone for the recording device when the switch couples the recording device to the call-forward event and reporting processor. The predetermined tone is a "fourth" column DTMF tone.
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