Patent ID: 7729331

Claim:
A terminal apparatus for sending and receiving data to and from a router that is connected to an external network to which a server apparatus is connected, said terminal apparatus being connected to the router via a home network and the router holding a corresponding relationship between a global address assigned to the router and a local address of said terminal apparatus for a predetermined period of time, said terminal apparatus comprising: a communication unit operable to send and receive data to and from the server apparatus via the router during a polling interval; and an adjustment unit operable to detect a holding period during which the corresponding relationship is held in the router, and to set a period shorter than the holding period as a sending interval at which the data is sent; wherein said communication unit is operable to send the data repeatedly to the router according to the sending interval, and said adjustment unit is operable to detect a longest response interval as the holding period in the router out of a plurality of response data sent by the server apparatus in response to the plurality of data sent by said terminal apparatus; and the corresponding relationship between the global address and the local address is always maintained as long as the terminal apparatus sends data packets to the router at the polling interval shorter than the holding period.