A system and method for establishing voice communication between a packet-switched network and a circuit-switched network includes a network interface unit for coupling to the packet-switched network, a phone interface unit for coupling to the circuit-switched network and a gateway processor coupled to the network interface unit and to the phone interface unit. In response to a call request, a packet-switched network connection is established between the gateway processor and a first station in the packet-switched network, and a circuit-switched network connection is established between the gateway processor and a second station in the circuit-switched network. Incoming voice data packets received from the first station are converted to outgoing voice signals, which are transmitted over the circuit-switched network connection to the second station. Incoming voice signals received from the second station are converted to outgoing voice data packets, which are transmitted over the packet-switched network connection to the first station. A conference call may be established among three or more conference call participants.