| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that although, when a call origination operation is performed by a telephone operator's telephone operation, a means is required for preventing a trouble occurring when a call is made to those who are previously known to refuse to be called, an analog telephone terminal has no function to restrict such a call, and, for that purpose, the analog telephone terminal has to be replaced with a computer-based telephone terminal control system and with a high-performance telephone facility capable restricting call origination, which results in diseconomy. SOLUTION: When a call is originated from an analog telephone terminal over a telephone communication line, a DTMF signal which is transmitted over the telephone communication line is detected and compared with information on a party to be called which is previously stored. If it is determined that the call is being connected to a wrong party, then the telephone communication line is blocked. COPYRIGHT: (C)2009,JPO&INPIT
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