Patent ID: 7489680

Claim:
A method of connecting a routing device in an existing wiring laid out between a first communication network and a client device for voice calls of said client device using said first communication network or a second communication network, comprising the steps of: preparing at least four electrically conductive wires designated as wires 2 , 3 , 4 and 5 respectively in said exiting wiring; connecting said first communication network to said wires 3 and 4 ; connecting a first mapping device to at least said wires 2 and 5 ; connecting said client device to said first mapping device which routes said client device to said wires 2 and 5 ; connecting a second mapping device to at least said wires 2 , 3 , 4 and 5 ; providing a foreign exchange subscriber (FXS) port, a foreign exchange office (FXO) port and a communication port for said routing device; connecting said routing device to said second mapping device which routes said FXS port to said wires 2 and 5 , and routes said FXO port to said wires 3 and 4 ; and connecting said second communication network to said communication port; wherein said routing device connects said FXS port to said communication port for voice calls of said client device using said communication network if said client device sends a pre-defined signal to said routing device, and connects said FXS port to said FXO port for voice calls of said client device using said communication network if said client device does not send said pre-defined signal.