| 摘要 |
Disclosed is an apparatus and method for switching between two network lines, such as telephone subscriber lines. Households and offices are increasingly equipped with multiple network lines for voice and data communications. The line switching unit of the present invention has a first terminal for receiving a CPE line from a CPE device. First and second switches of the unit each connect a common terminal to a first switched terminal responsive to a first value of a control signal received at a control terminal of each switch and to a second switched terminal responsive to a second value of the control signal. The first switched terminal of the first switch is connected to the first terminal and the second switched terminal of the second switch is connected to the first terminal. The common terminal of the first switch is connected to a first network line and the common terminal of the second switch is connected to a second network line. A further aspect of the present invention includes a control unit that senses an off-hook signal on the CPE line and, when the control signal is in a state of outputting the first value, checks a state of the first network line to determine if it is in use. If the first network line is in use, then the control unit checks a state of the second network line. If the second network line is not in use, then the control unit changes the state of the control signal to output the second value of the control signal.
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