Abstract: A time management method for a switching system include: periodically checking a failure state of an HW time using an OMDC; setting the HW time or a user time as an initial system time in accordance with the failure state of the HW time; resetting a system time by periodically comparing the HW time or an MP time, in which an IPC delay is considered, with an OMP time; requesting the initial system time to an OMP; setting an initial MP time as the received OMP time; and periodically comparing the MP time in which the IPC delay is considered with the OMP time and thereby resetting the MP time.

Abstract: A call supervisory system in the exchange includes: a trunk card device (TCD) connected to a trunk card of an external system via a control trunk line (CTL); a device control unit (DCU), as a lower level processor, for controlling the TCD; a man machine interface unit (MMIU) matched with the external system for switching data and managing a password; a call trace and path setup control unit (CTCU) for controlling the call supervisory system according to demands of the external system received through the MMIU and informing a result of the relevant control to the external system via the MMIU; a number translation unit (NUTU) for translating and managing the exchange number when processing calls according to the control of the CTCU; a call trace and path setup unit (CTSU) for setting up call supervision and a call path according to the control of the CTCU; a call management unit (CMU) for performing a call process function of the exchange, sending a call supervision control flag to NUTU, and informing occurrenc