Verfahren zum Ermöglichen einer Nachprüfung der Gebührenabrechnung und Vorrichtung zur Durchführung des Verfahrens

The verification involves the detection of the electrical states or processes on the lines of the network connection, and the automatic storage of the acquired information after the automatic ordering of the time data. An authentication process produces tokens automatically by means of a secret key from the subscriber terminal, for checking by a line-monitoring unit. The separation of this process from the data acquisition and storage, as well as the alteration of the recorded data, are feasible only by detectable manipulations of the terminal.