| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To be able to provide a communication system, etc. which appropriately process an IP address and a port number used for communications when a terminal performs P2P communication with another communication partner over a router. <P>SOLUTION: The router 104 memorizes a lookup table of the IP address and the port number of the terminal 106 in a local communication network 103 and a port number in a wide area communication network 102, and relays communications between a device in the wide area communication network 102 and the terminal 106 referring it. A server 105 memorizes a lookup table including the same information of the lookup table, if the terminal 106 requests an inquiry to the server 105 specifying the IP address and the port number of the terminal 106 in the local area communication network 103, it returns an answer of the request specifying the IP address of the router 104 in the wide area communication network 102 regarding to the lookup table, and the port number in the wide area communication network 102 acquired from the lookup table. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
