Abstract: A method and apparatus for enabling multiple protocol communication over a network are disclosed. A first circuit communicates first signals in a first frequency band using a first data protocol and attenuates second signals in a second frequency band using a second data protocol. The first data protocol supports a first modulation technique and a second modulation technique. A second circuit communicates the second signals in the second frequency band using the second data protocol.

Abstract: A filtering device (50) for active filtering at a customer premises includes an input interface that receives telephone signals and digital data signals communicated from a central office (14) using a telephone line (12). The filtering device (50) further includes an active low-pass filter (60) that receives the telephone signals, the digital data signals, and electrical power from a power source. The active low-pass filter (60) attenuates the digital data signals and passes the telephone signals using the electrical power. The filtering device (50) also includes an output interface that receives the telephone signals from the active low-pass filter (60) and communicates the telephone signals to a telephone (42).

Abstract: A line card or other telephone or communications interface provided with a ringing SLIC outputs relatively high voltage, such as in excess of about 90 volts, and/or relatively high current such as in excess of about 20 milliamps during normal use, but decreases the voltage or current of a ringing signal or other signal upon occurrence of a tip and/or ring line fault or other abnormal condition. The abnormal condition is detected by measuring voltage and/or current on the tip line and/or ring line. In response to an excess voltage or current, the ringing current or other output current is reduced to achieve desired safety and/or compliance with standards.

Abstract: An improved PC/104 connector includes a pin by pin isolation mechanism to allow a standard PC/104 connector pin to transmit non-PC, vendor-specific I/O signals between stacked PC/104 modules.