Abstract: An address resolution device includes a gate keeper having an address table with which global addresses, private addresses, and grouping IDs can be registered. During address registration, the gate keeper registers the address of a communication packet into the global addresses, the address assigned to the terminal into the private addresses, and if available, a Grouping ID into grouping IDs. During address notification, the gate keeper consults the address table to notify the caller terminal of the callee terminal private address when the callee terminal and the caller terminal have the same Grouping ID or when they have the same global address. Otherwise, the gate keeper notifies the caller terminal of the callee terminal global address.