A first data center includes a first virtual network that provides a communication service in cooperation with at least a part of a communication facility of a first communication operator and a first communication unit that is operable to communicate with a second data center. The second data center includes a second virtual network that provides a communication service in cooperation with at least a part of a communication facility of a second communication operator and a second communication unit that is operable to communicate with the first data center. The first communication unit is operable to transmit to the second communication unit, communication data to be transmitted from a first terminal connecting to the first virtual network via a communication facility of the first communication operator to a second terminal connecting via a communication facility of the second communication operator to the second virtual network.