A voice-over-internet system and method is disclosed which comprises a gateway (40) and a separate remote gateway (50) which can each provide signals between a radio (12) and a user terminal (24) via the internet (22). If one of the gateways fails, the other gateway is able to take over the communication role. Data is synchronised between the gateways and a polling protocol is used to determine whether one of the gateways remains active or whether the other gateway should assume the active role.