Abstract: The present invention provides a method and apparatus for prepayment of telecommunication connections between first and second telecommunication devices operably associatable with the telecommunication lines of a telecommunication switching network. In general, the method involves storing telecommunication-time data representative of a prepurchased amount of telecommunication-time available for payment of telecommunication connections in the telecommunication switching network. At the initiation of the first telecommunication device, a telecommunication connection is established between the first and second telecommunication devices so that a telecommunication process can be conducted therebetween. The telecommunication connection between the first and second telecommunication devices is terminated in response to termination of the telecommunication process. The time duration of the telecommunication connection is measured.

Abstract: Disclosed is a circuit which permits automatic switching between a main line and spare line at a subscriber's network interface device. A relay is provided between the two lines, which relay is triggered by a ringing signal on the line to be used.