A cordless security system that communicates through a wireless telephone network. A wireless node, having a wireless transceiver adapted to communicate wireless signals with the wireless telephone network, and a cordless transceiver adapted to communicate cordless signals with plural cordless terminal devices enables a cordless local area network. The wireless node also includes a controller that operates to couple telephone calls between the wireless transceiver and the cordless transceiver. The controller routes cordless data packets in the cordless signals through the cordless transceiver and amongst the plural cordless terminal devices. The cordless security system includes plural cordless security sensor terminal devices that communicate cordless sensor signal encoded within a cordless data packet into the cordless local area network. A cordless security control panel terminal device communicates cordless alarm signals encoded within a cordless data packet into the cordless local area network. The control panel also transmits a cordless outgoing audio message within the cordless local area network. A cordless security alarm terminal device, such as a siren produces an audible output.