Abstract: An arrangement for testing the connection from a new switching system to a subscriber line, which is also operationally connected to an electro-mechanical switching system. Operational service is to be transferred from the electromechanical switching system to a digital switching system. The arrangement for verifying the subscriber's line connection provides a high frequency current transmitted through the exchange to be removed from service, through the subscribers double jumper connection to the new exchange line equipment, via a capacitor direct current isolator to a test bus associated with the subscriber's line equipment.

Abstract: An arrangement for automatically testing a plurality of subscriber lines, which are operationally connected to an electromechanical switching system is shown. Operational service is to be transferred from the electromechanical switching system to a digital switching system. This arrangement provides for automatically verifying whether the digital switching system is arranged to apply the proper ringing signal to each subscriber by a comparison with that applied by the electromechanical switching system.