Abstract: The method defines steps and sequences for dealing with peripheral units reported as defective in a communications system. A repetition counter for counting a number of start-up attempts is provided for a restarting procedure. During a locked phase, the peripheral unit that is affected is temporarily taken out of service. After that, a monitoring phase with a temporary start-up is initiated during which tests for faults are carried out. If the unit is determined to be free from faults, a final start-up takes place following the monitoring phase. In the case of a fault during the monitoring phase, the count of the repetition counter is compared with a threshold value. A final taking-out-of-service takes place if the count of the repetition counter exceeds the threshold value. Otherwise, the repetition counter is incremented and another transition into the locked phase takes place. The duration of the locked phase is dependent on the count of the repetition counter.

Abstract: Method and apparatus for synchronizing a clock of a telecommunication switching system. The clock of the telecommunication switching system is supplied, at least at times, with reference clock signals from a plurality of external reference clock sources. Every external reference clock source has a predetermined priority allocated to it. The supplied reference clock signals are checked for clock errors to which individual errors are allocated. For synchronization, the clock accepts an external reference clock signal dependent on the priorities allocated to the reference clock sources and dependent on the clock-error-associated error values. In an initialization, initial error values are allocated to the reference clock sources. In a re-initialization of the system, the synchronization procedure is continued from the current error values that are present at the time of the system outage.

Abstract: A busy signal connecting set is immediately released by the disengagement of a connecting station participating in an existing connection, and a state of interception is established for the subscriber circuit of the subscriber station which has not yet released. The subscriber circuit is connected with a house set for the purpose of connecting the busy signal by way of time switching equipment which is activated after a delay time in response to production of the state of interception.