The present invention provides for a system and method for providing a signal to a communication system comprising an interface between a communication link and the communication system, like an alarm system, wherein the interface receives a signal from the communication link and provides a signal indicative of the availability of the communication link for use by the communication system. Alarm systems operations may be facilitated so that Residential Gateway components (such as voice terminal adapters) may simulate traditional telephone network systems that run on 48 VDC powered telephone lines. The system also comprises an input port associated with the interface for receiving the signal from the communication link, a transformer or a voltage regulator and an output port associated with the interface for providing the conditioned signal to the communication system. A ring voltage received from the communication link may be passed through to the alarm system.