| 摘要 |
A call saving system for an ISDN telephone switching system includes a subscriber switching unit and terminal units connected to the subscriber switching unit via subscriber lines. A control device controls an overall call saving process executed between the subscriber switching unit and each terminal unit when a restart process is started after a call process is temporarily stopped. When a restart process is started, a restart message is transmitted to each terminal units on the basis of the presence/absence of a call to be saved. Each terminal unit includes a call state setting circuit for a state display message when information indicating a confirmation of a call saving is set in the restart message.
|
