An acquisition unit acquires a state of a server including pieces of virtual CPE, and an instructing unit instructs CPE connected to the virtual CPE to control a communication band based on the state of the server. The instructing unit instructs the CPE to limit a communication band to a predetermined value or less based on a CPU usage rate acquired by the acquisition unit exceeding a predetermined threshold value. The instructing unit instructs the CPE to limit a communication band to a predetermined value or less in based on the number of connections of the CPE acquired by the acquisition unit being less than a predetermined threshold value. The acquisition unit acquires presence or absence of CPE not connected to the virtual CPE, and the instructing unit instructs the CPE to block communication based on the presence of CPE not connected to the virtual CPE.