MAIN DEVICE OF TELEPHONE SYSTEM AND ITS OPERATION METHOD

PROBLEM TO BE SOLVED: To provide a main device of a telephone system and its operation method such that an on-hold call can be automatically reconnected to the original telephone set and that can be reported to the user of the telephone set to eliminate the need to examine the reconnection method.SOLUTION: Once receiving a transfer indication to connect a call connected to a first telephone set and then placed on hold to a second telephone set from the first telephone set, a function provision determination section of the main device determines whether the call can be connected to the second telephone set on the basis of the state of the telephone set managed by a telephone set state management section (S1), and controls a guide transmission part so as to transmit a reconnection guidance showing that the call is to be connected to the first telephone set (S7) when determining that the call cannot be connected.