A cordless telephone system includes a base station and a handset. The base station includes a telephone line interface, a base station chipset coupled to the telephone line interface, and a first radio transceiver coupled to the base station chipset. The handset includes a microphone, a speaker, a processor coupled to the microphone and the speaker, a wireless network interface coupled to the processor, a handset chipset coupled to the processor, and a second radio transceiver coupled to the wireless network interface and the handset chipset. The second radio transceiver is operable to communicate with the first radio transceiver and a third radio transceiver at a device coupled to a computer network. In a cordless telephone mode, a telephone call is communicated between the handset and the base station. In an IP telephone mode, an IP telephone call is communicated between the handset and the device.