Network control device, communication system, network control method, program, and recording medium

A network control device that performs control of a system including a plurality of gateway devices that are electrically coupled to a predetermined network, and a plurality of terminals, comprising:

• processing circuitry configured to:
• select a first gateway device used by a first terminal based on a quality between the first terminal and the plurality of gateway devices;
• and
• perform a path control, such that,
• upon determining that a second gateway device used by a second terminal that is a communication destination of the first terminal is same as the first gateway device, traffic from the first terminal to the second terminal is routed without using the predetermined network, through a tunnel established between the first terminal and the second terminal, and
• upon determining that the second gateway device is different from the first gateway device, as a path for traffic routed from the first terminal to the second terminal, either of a first path via the predetermined network or a second path without using the predetermined network is selected based on a quality of the first path as well as a quality of the second path, and the traffic from the first terminal to the second terminal is routed along the selected path.

A network control method performed by a network control device that performs control of a system including a plurality of terminals and including a plurality of gateway devices that are electrically coupled to a predetermined network, comprising:

• selecting a first gateway device used by a first terminal based on a quality between the first terminal and the plurality of gateway devices;
• connecting between the first terminal and each of other terminals that uses the first gateway device, via a tunnel;
• and
• performing a path control, such that, upon determining that a second gateway device used by a second terminal that is a communication destination of the first terminal is same as the first gateway device, traffic from the first terminal to the second terminal is routed, without using the predetermined network, through a tunnel established between the first terminal and the second terminal, and such that, upon determining that the second gateway device is different from the first gateway device, traffic from the first terminal to the second terminal is routed through the predetermined network.