A system is provided for connecting an alarm system to a monitoring center through a fiber optic network. The alarm signals may be transmitted through the electrical wiring within a house or other facility through a fiber optic network and the PSTN and/or Internet to the monitoring center. The connection may include a reverse polarity in a pair of ring and tip lines between an interface device of the fiber optic network and a junction element of the alarm system or between the junction element and a controller of the alarm system. The reverse polarity may be created by connecting an end of a ring line into a tip adapter and connecting an end of a tip line into a ring adapter.