TELEPHONE SYSTEM AND TELEPHONE TERMINAL FOR THE TELEPHONE SYSTEM

PROBLEM TO BE SOLVED: To easily detect presence/absence of any type of terminal or master unit while attaining reduction of communication network load. SOLUTION: According to embodiments, a telephone terminal connected through a communication network to a master unit, which performs communication between a plurality of telephone terminals registered in a terminal management table, is targeted and includes a timer, a transmission means and a detection means. The timer starts counting a predetermined time in timing to transmit a connection confirmation signal for confirming presence/absence of a connection with the master unit. After the lapse of the predetermined time, set for each terminal, as a time from transmission counted by the timer, the transmission means transmits the connection confirmation signal to the master unit. If a response signal to the transmission of the connection confirmation signal is redirected from the master unit, the detection means detects the presence of the master unit. COPYRIGHT: (C)2011,JPO&INPIT