Network control apparatus and network control method

A network control device, comprising:

• a data collector configured to collect, from a relay device in a network system in which a packet is relayed between a first communication device and a second communication device via a relay network including one or more of the relay devices, uplink observation data indicating traffic volume of a processing request packet addressed to the second communication device from the first communication device and downlink observation data indicating traffic volume of a response packet transmitted from the second communication device in response to the processing request packet, the uplink observation data and the downlink observation data being acquired by observing the packet input to the relay device;
• a controller configured to change a shaping rate in the relay device included in the relay network, the shaping rate being a speed at which the packet addressed to the second communication device passes through the relay device, based on a ratio between the traffic volume in a first period indicated by the uplink observation data and the traffic volume in a second period indicated by the downlink observation data, or a ratio between an increment of the traffic volume in the first period acquired from the uplink observation data and an increment of the traffic volume in the second period acquired from the downlink observation data;
• and
• wherein the second period is the time passed after the first period by the sum of the round-trip propagation delay from the relay device to the second communication device and the processing delay in the second communication device.