Patent ID: 7457884
Filing Date: 2008-11-25
Classification: H04L

Abstract:
1. A method for determining if a communication application program is operable in a network environment of a first terminal prior to commencement of communication between the first terminal and a second terminal via the network, the method comprising: investigating the network environment related to the first terminal in which the communication application program is operated using a first investigation method; further investigating the network environment related to the first terminal using a second investigation method; and providing a message to the first terminal indicating that there is a possibility that the communication application program cannot be used based upon a result of the investigations, wherein the first investigation method includes investigating an IP address allocated to the first terminal, and judging whether or not the investigated IP address corresponds to a global IP address; and wherein the second investigation method includes at least one of: acquiring an externally-recognized IP address as to the first terminal, and comparing the externally-recognized IP address with an IP address allocated to the first terminal in order to judge whether or not the externally-recognized IP address is consistent with the IP address allocated to the first terminal; and externally executing a port-scanning operation with respect to a port used in the communication of the first terminal in order to judge whether or not the port-scanning operation succeeds.