Patent ID: 8325740

Claim:
A voice-over-internet system comprising: a pair of radio communication gateways comprising: a first gateway serving as a primary gateway and having a first physical IP address and a virtual IP address; and a second gateway remote from the first gateway serving as a secondary gateway and having a second physical address different from said first physical IP address; a radio device for supplying a voice signal and a control signal to the first and second gateways; and a selection mechanism for determining which of the first and second gateways is the gateway responsible for transmitting the voice signal to a voice-over-internet protocol user terminal and for handling call signalling via the internet, said selection mechanism being operative for communicating between the first and second gateways to facilitate selection of one of the first and second gateways to transmit the voice signal to the internet and then to a voice-over-internet protocol user terminal, and for synchronising data between the first and second gateways so that both the first and second gateways contain operational data so that if communication is changed from one gateway to another gateway, the another gateway includes the communication data required to permit the another gateway to perform the complete functionality of the one gateway after the another gateway becomes active and to continue the communication between the radio device and the user terminal, wherein each gateway has a radio path connecting the gateway to a user terminal via the internet, wherein, the first and second gateways communicate with each other via the internet, using physical IP addresses, wherein the selection mechanism comprises a processor in each of said primary gateway and said secondary gateway, each processor communicating with the other processor for determining whether the primary gateway is operating and whether a communication and call signalling path associated with that primary gateway is therefore operating so that one of the first and second gateways can be selected for supplying the voice signal from the radio device to the user terminal via a radio communication path through the internet and for handling call signalling, wherein, upon start up, a gateway asserts that it wishes to be the active gateway, and will be the active or standby gateway depending on (1) whether a reply is received from the other gateway within a predetermined period of time and (2) the nature of the reply, wherein, after start up, the processor in each gateway constantly polls the other gateway by sending a life check packet to the other gateway using the physical IP address and, if the other gateway fails to respond within a predetermined time frame M for N consecutive times, the other gateway is deemed to have failed, and wherein, if the primary gateway is thereby deemed by the standby gateway to have failed, the secondary gateway activate itself as the primary gateway to provide the communication and call signalling path between the radio device and the user terminal.