Telephone communication system and method over local area network wiring

The invention claims with made of confined to the protective circuit structure is connected with the bearing digital data and an input signal method and device in the same transmitting medium. A special is suitable for all remote data unit (e.g. personal computer) and a two-way data communication circuit the cable connecting wire comprises at least two pairs by a a star topology a network to concentrator. The disposed on two pairs of wires through phantom circuit for is a a data device telephone a telephone (voice frequency signal) and PBX to provide a ghost circuit in the cable two ends module. Such communication circuit is, each interference. The are composed of all simple and economical passive electric circuit component.