发明名称 Device to block unauthorized modem access over a PBX line
摘要 A modem detector that enables detection of whether a modem is coupled to a phone line. When one is detected, various responses can occur, including: hanging up on the modem; checking if the modem linkage is allowable and, if it is not, then hanging up on the modem; and/or logging in the occurrence of an unauthorized modem access. To provide protection against unauthorized modem access, a digital embodiment can be used at the T1 phone line or an analog embodiment can be used after digital telephone data is converted into analog signals.
申请公布号 US5018190(A) 申请公布日期 1991.05.21
申请号 US19890410689 申请日期 1989.09.21
申请人 HEWLETT-PACKARD COMPANY 发明人 WALKER, RICHARD C.;VON BRAUN, HANS
分类号 H04M11/00;H04M11/06 主分类号 H04M11/00
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