Patent ID: 8737396

Claim:
A communication method comprising: associating, by a server, a permitted terminal identifier for identifying a permitted terminal permitted to perform tunnel communication with a first router apparatus set as an endpoint with an endpoint address of a tunnel used in the communication of the permitted terminal; inquiring of the server an endpoint address associated with an identifier for identifying a requesting terminal, which requests the tunnel communication, by a second router apparatus that encapsulates a packet received from the requesting terminal; notifying the second router apparatus of a target address that is the endpoint address associated with the identifier for identifying the requesting terminal by the server when the server detects the target address; transmitting the encapsulated packet to the target address by the second router apparatus; regarding a received packet received at the target address as a packet used in the tunnel communication of the permitted terminal by the first router apparatus to which the target address is allocated; and decapsulating the received packet and then transmitting the decapsulated packet to a communication destination of the requesting terminal, wherein a first endpoint address and a second endpoint address which are endpoints of tunnel communication with the first router apparatus set as an endpoint are allocated to the first router apparatus, when a first permitted terminal permitted to perform communication through a first transfer destination requests communication with the communication destination, the server notifies the second router apparatus of the first endpoint address and, when a second permitted terminal permitted to perform communication through a second transfer destination requests communication with the communication destination, the server notifies the second router apparatus of the second endpoint address, and the first router apparatus transmits a first packet obtained by decapsulating a packet addressed to the first endpoint address to the first transfer destination and transmits a second packet obtained by decapsulating a packet addressed to the second endpoint address to the second transfer destination.