Patent ID: 7920683

Claim:
A method for verifying charge invoicing for a communications connection according to time intervals, a testing device able to simulate at least one calling analog terminal device and at least one called terminal device being connected to at least one network node that can generate time pulses, the method comprising: at least one predetermined test-communications connection is set up and cleared again via at least the one network node; ascertaining the respective time interval between a start of the test-communications connection and a generation of a first time pulse; determining if the ascertained respective time interval is within a first predetermined time domain; during the test-communications connection, measuring time-unit intervals of consecutive time pulses and comparing the measured time-unit intervals of consecutive time pulses to a predetermined time interval; and determining if at least one additional time pulse has been received after an end of the test-communications connection, wherein if the at least one additional time pulse has been received after an end of the test-communications connection then the interval between the end of the test-communications connection and the at least one time pulse is ascertained, and a determination of whether the ascertained interval is within a second predetermined time domain is made, and wherein the time interval between the start of the test-communications connection and the generation of the first time pulse is ascertained by: detecting an occurrence of a first predetermined event, which corresponds to a measurable start of the test-communications connection, at a first predetermined measuring point of the testing device; detecting a reception of a first time pulse of the test-communications connection generated by a network node at a second predetermined measuring point of the testing device; and as a function of the detected occurrence of the first predetermined event and the reception of the first time pulse, effecting one of starting and stopping a time measurement is started or stopped, wherein a systematic measuring error between a location of an actual occurrence of the start of the test-communications connection and a first measuring point of the testing device is ascertained, a systematic measuring error between a location of an actual generation of the first time pulse and a second measuring point of the testing device is ascertained, an interval between a detected occurrence of the first predetermined event and the reception of the first time pulse is measured and corrected by an amount of the systematic measuring error; and a determination is made whether a corrected interval is within the first predetermined time domain.