Patent ID: 7099463

Claim:
A communication device comprising: a port having a plurality of electrical conductors for communicating with a data terminal equipment (DTE) device; a signal generator for providing a detection signal over a first pair of the plurality of electrical conductors using common mode signaling; a signal analyzer for receiving a response signal responsive to the detection signal from the DTE device over a second pair of the plurality of electrical conductors using common mode signaling; a source of electrical power for providing a phantom power signal to the DTE device; a switch responsive to the signal analyzer for connecting the source of electrical power to one of the first and second pairs of the plurality of electrical conductors; and a physical layer device coupled to receive data signals from a selected one of the first and second pair of the plurality of electrical conductors, and wherein the signal analyzer is responsive to a signal from the physical layer device indicating that data signals are being received by the physical layer device over the selected one of the pairs of the plurality of electrical conductors to prevent the connection of electrical power to the one of the first and second pairs of the plurality of electrical conductors.