Patent ID: 8774183

Claim:
A relay device disposed within a LAN for connecting a client apparatus with a virtual network via a server on the Internet, said relay device comprising: a server address storage section for storing a global address of said server on the Internet; a tunneling connection establishing section for establishing a tunneling connection between said relay device and said server based on said global address of said server, thereby enabling communication destined to a virtual network address of said virtual network, wherein said relay device is disposed between an upstream network and a downstream network within the same LAN, said upstream network having a client apparatus communicating in a first protocol and said downstream network having a client apparatus communicating in said first protocol and at least one client apparatus communicating in a second protocol wherein said first protocol is an internet protocol version four (IPv4) protocol and said second protocol is non-IPv4 protocol; a bridge module provided between a local communication protocol stack and a network device for determining a destination of a packet received via the network device, and bridging between the upstream network and downstream network of the LAN by letting the packet pass through without passing the packet to the local communication protocol stack unless the packet is addressed to the relay device itself, a broadcast packet, or a request packet addressed to the virtual network, as well as for capturing and forwarding a request packet that is originated from said at least one client apparatus communicating in said second protocol in the downstream network and that is destined to a virtual network address of said virtual network to a capsulating processing section without passing the packet to said local communication protocol stack; said capsulating processing section for receiving said request packet and capsulating the packet after adding to the packet a virtual network address of said at least one client apparatus as an originating address, and sending the capsulated packet to said server via the tunneling connection; and a decapsulating processing section for decapsulating a packet addressed to the relay device itself received through said local communication protocol stack via the tunneling connection, converting a destination virtual network address included in the decapsulated packet into a private IP address of said at least one client apparatus in the downstream network, and sending the packet to said at least one client apparatus by the bridge module without passing the packet to the said local communication protocol stack; wherein said bridge module passes a broadcast packet to said local communication protocol stack and also let the broadcast packet to pass through.