| 摘要 |
<p>A network system, a communication method, information processing apparatus, method and program for allowing an apparatus to easily have communication with another apparatus via NAPT. A local communication apparatus (11) acquires a provided service packet from an apparatus-application service provider apparatus (51) via a port (342-1) of a relay apparatus (12) and also acquires a provided service packet from an apparatus-application service provider apparatus (52) via a port (342-2) of the relay apparatus (12). Then, the local communication apparatus (11) calculates a difference value between two pieces of global address information included in the foregoing provided service packets, and predicts, based on the difference value, that a port (342-3) is one that will corresponds to the next communication. The present invention is applicable to an instant message service system.</p> |
