Patent ID: 7768997

Claim:
A system for providing public switched telephone network (PSTN) line backup to a voice over a packet protocol service, comprising: a local device configured to drive local site wiring when the voice over a packet protocol service is being used; and a switch configured to disconnect the PSTN line from the local site wiring if the local site wiring is being driven by the local device and connect the PSTN line to the local site wiring if the local site wiring is not being driven by the local device, wherein the local device is configured to detect the availability of a broadband connection and to enable driving the local site wiring if the broadband connection is available and to disable driving the local site wiring if the broadband connection is not available, wherein the local device is further configured to periodically send and receive messages over the broadband connection to determine if the broadband connection is available, and wherein the switch comprises a relay, the relay being connected between the local site wiring and the PSTN line and having an actuating coil of the relay coupled to the local site wiring, and wherein the actuating coil is connected to the PSTN line through a contact of the relay.