Telephone line security apparatus
First Claim
1. A telephone call-in security apparatus for controlling connections between a single telephone line and a telephone modulator-demodulator (modem) apparatus at a location remote from a telephone switching station and connected to a publically accessible switched telephone network, said security apparatus comprising:
- means coupled to said telephone line for detecting ring signals;
means responsive to said ring signal detecting means for connecting said apparatus to said telephone line in a two-way telephone connection;
means coupled to said telephone line through said connection means for detecting tone encoded signals of an incoming telephone call;
means operative to check said detected tone encoded signal for an authorized access code for initiating a call-back sequence to a telephone terminal corresponding to said access code, said call-back sequence initiating means including means for detecting for a forward disconnect condition from the switched telephone network;
andmeans responsive to a two-way telephone line connection sequence subsequent to said call-back sequence for coupling said telephone line to said modem.
4 Assignments
0 Petitions
Accused Products
Abstract
A telephone security apparatus placed at a subscriber station intercepts and screens incoming calls direct to a terminal through a modem. The security apparatus prevents completion of a connection to the terminal equipment unless the incoming call provides a predefined access code and the call is found to have been made from the remote subscriber station to which the predefined access code has been assigned. The security apparatus automatically dials back the subscriber station corresponding to the access code given on the incoming call. A microprocessor-based embodiment is described.
27 Citations
7 Claims
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1. A telephone call-in security apparatus for controlling connections between a single telephone line and a telephone modulator-demodulator (modem) apparatus at a location remote from a telephone switching station and connected to a publically accessible switched telephone network, said security apparatus comprising:
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means coupled to said telephone line for detecting ring signals; means responsive to said ring signal detecting means for connecting said apparatus to said telephone line in a two-way telephone connection; means coupled to said telephone line through said connection means for detecting tone encoded signals of an incoming telephone call; means operative to check said detected tone encoded signal for an authorized access code for initiating a call-back sequence to a telephone terminal corresponding to said access code, said call-back sequence initiating means including means for detecting for a forward disconnect condition from the switched telephone network; and means responsive to a two-way telephone line connection sequence subsequent to said call-back sequence for coupling said telephone line to said modem. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification