| 摘要 |
PROBLEM TO BE SOLVED: To perform the no-ringing communication with no use of no-ringing trunk by identifying whether the calling is given from a center device based on the detected caller number signal and performing the no-ringing communication with a telephone set separated from a telephone circuit when the calling is given from the center device. SOLUTION: When the calling is given from the center side by means of the telephone circuits L1 and L2 where the caller information signals are added to the call signals, a controller 10 of the terminal side detects a call signal (linger) and a caller number that is transmitted in a pause period of the call signal. If it is identified that the detected caller number is given from the center side, the transmission of data is started in reply by the no-ringing communication. If the detected caller number is not given from the center side, both circuits L1 and L2 re connected to a telephone set 11 and the telephone users can use these circuits L1 and L2. |
