An internet terminal ( 110 ) according to the present invention is comprised of: a communication unit ( 111 ) that sends a local packet generated by a packet generation unit ( 113 ) and receives a response local packet from a server apparatus ( 200 ); an encryption processing unit ( 112 ) that encrypts the local packet to be sent out and decrypts the received response local packet; the packet generation unit ( 113 ) that generates the local packet; a polling information storage unit ( 114 ) that holds a terminal ID and a password used for identifying the internet terminal ( 110 ); a polling interval adjustment unit ( 115 ) that identifies a polling interval at which the local packet is periodically sent to the router ( 101 ); and a control unit ( 116 ) that sends control information to a terminal apparatus to be controlled and controls such terminal apparatus accordingly.