| 摘要 |
PROBLEM TO BE SOLVED: To ring a bell tone corresponding to a telephone number by distinguishing a toll telephone number supplied from a caller from a telephone number excluding the toll telephone number through the use of an incoming sub address in a telephone set adopting the ISDN communication system. SOLUTION: The telephone set adopting the ISDN communication system uses a number division means 2 that divides a caller toll station number written in an incoming sub address and a number excluding the toll station number, a tone name conversion means 3 converts the telephone number into a corresponding tone name on the basis of the divided data, a time information provision means 4 decides a time corresponding to the tone name and a ringing tone generating means 6 and a speaker 7 sequentially ring a melody to distinguish the toll station number from the succeeding telephone number. |
