| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a communications apparatus for discriminating a NAT type, with high accuracy. <P>SOLUTION: The communications apparatus includes a first transmitting section 101 for transmitting a plurality of request messages the combination between a sender IP address port number and a destination port, the number of which differs from each other; receiving sections 103, 104 for receiving a response message sent by by a server 140; a response message storage section 107 for storing the response message; a first conversion method discriminating section 105 for discriminating that a conversion method by a network relaying apparatus is not an address conversion method for respectively converting a sender IP address and a sender port number into a prescribed value by each combination of the protocol, the sender IP address, and the sender port number; a second transmission section 102 for transmitting an acknowledgement message, when the response message cannot be received; and a second conversion method discriminating section 106 for discriminating that the conversion method is not the address conversion method, when the response message in response to the acknowledgement message can be received. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
