VPN DEVICE, IP COMMUNICATION APPARATUS, AND SERVER DEVICE

摘要

PROBLEM TO BE SOLVED: To establish stable and continuous communication even if a communication failure occurs during P2P communication.SOLUTION: A communication control section 140 finds a communication failure which is a cause for difficulty in the continuity of P2P communication based on the condition that Keep-alive packet is not received for a time longer than or equal to a predetermined time period from a device on the other side and an error occurrence rate of a specified value or higher continues for a predetermined period or longer by using a communication failure detecting section 147 while P2P communication conducted by the device on the other side. Upon the detection of the communication failure, the communication control section 140 carries out shifting processing to communication via a server that uses a relay server provided in an IP network to switch the P2P communication to communication via a server.