A switch device for use in a gateway equipment and a gateway equipment comprising the switch device are suggested. The suggested switch comprises a Foreign Exchange Station (FXS) port configured to be connected to a telephone set, a Foreign Exchange Office (FXO) port connected to communicate analog voice signals with an external network, and a Voice over Internet Protocol (VOIP) unit configured to communicate digital data signals with the external network and enable a VOIP call using the digital data signals. The switch device comprises a switch configured to, when the gateway equipment is power down, connect the FXS port to the FXO port. The switch device also comprises a power unit configured to generate a work voltage from the analog voice signals at the FXO port to provide a power supply to the switch.
