Patent ID: 8509247

Claim:
A method of performing communication between a first network and a second network via a third network to which a router of the first network and a router of the second network are connected, said method comprising: transmitting a connection request including communication-direction information which is defined in a protocol for connecting between the first network and the second network and indicates the direction of communication of a first service provider that exists on the first network, from the first network to the second network via the third network using the protocol for connecting between the first network and the second network; searching, using a protocol used in the second network, for a second service provider which exists on the second network and which has a function corresponding to the communication-direction information defined in the protocol for connecting between the first network and the second network; forming, based on information which is defined in the protocol used in the second network and identifies the second service provider having the function corresponding to the communication-direction information, identification information which is defined in the protocol for connecting between the first network and the second network and identifies the second service provider having the function corresponding to the communication-direction information; and transmitting the identification information from the second network to the first network via the third network using the protocol for connecting between the first network and the second network.