RECEIVING TERMINAL FOR OUTGOING TELEPHONE NUMBER INFORMATION OR THE LIKE FOR ANALOG TELEPHONE LINE

PROBLEM TO BE SOLVED: To ensure a normal operation even in a branch connection mode and also to receive an outgoing ID for a receiving terminal by adding a function which performs no transfer of signals to an analog subscriber switchboard and receives the relevant information when the analog subscriber switchboard transmits the outgoing ID by means of a modem signal. SOLUTION: A circuit state monitoring part 16 detects the IC (incoming) received from an analog subscriber switchboard 3 to notify a control part 11 of this detection, and the connection is opened at a circuit switching part 15A among the lines L1 and L2 and a communication terminal B. Thus, the OG (outgoing) is impossible for a communication terminal part 2. When an outgoing ID terminal start signal detection part 12 detects that the signal inputted via the lines 15a and 15b of high impedance is equal to an outgoing ID signal, the part 15A keeps its state as it is and the part 16 monitors an analog outgoing ID receiving terminal for reception of the outgoing ID. If no outgoing ID terminal start signal is detected, the part 15A connects both lines L1 and L2 to the terminal B.