ROUTING CONTROL METHOD AND SYSTEM

• US 20090046729A1
• Filed: 08/14/2008
• Published: 02/19/2009
• Est. Priority Date: 08/17/2007
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Nagata, Nami
• Granted Patent: US 8,432,877 B2
• Time in Patent Office: Days
• US Class Current: 370/401
• CPC Class Codes: H04L 12/4641 Virtual LANs, VLANs, e.g. virtual private networks [VPN] LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/243 using M+N parallel active paths
• CPC Class Codes: H04L 61/2514 between local and global IP addresses
• CPC Class Codes: H04L 61/2528 Translation at a proxy
• CPC Class Codes: H04L 61/5014 using dynamic host configuration protocol [DHCP] or bootstrap protocol [BOOTP]
• CPC Class Codes: H04W 4/00 Services specially adapted for wireless communication networks; Facilities therefor
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user

Abstract

A VPN server encapsulates a packet P2 upon receiving the packet and distributes packets P (2-1) and P (2-2) to wireless terminals MN1 and MN2 respectively. The wireless terminal MN1 decapsulates the packet P (2-1) (as packet P2-1) upon receiving the packet and transmits the packet P2-1 to a wireless terminal MN3. Thus, the packet is transmitted by a communication path: file server 102—VPN server 101—wireless terminal MN1—wireless terminal MN3. The wireless terminal MN2 decapsulates the packet P (2-2) (as P2-2) upon receiving the packet and transmits the packet P2-2 to the wireless terminal MN3. The packet P2-2 is transmitted by a communication path: file server 102—VPN server 101—wireless terminal MN2—wireless terminals MN3.

Claims

1. A packet routing control method, wherein a local network in which a plurality of terminal devices exist and a remote network in which a VPN server and a file server exist are VPN-connected includes the following processes;

a terminal device is designated as a gateway among the plurality of terminal devices, the gateway terminal device receives a VPN address assigned to a specific terminal device from the VPN server and provides the VPN address to the specific terminal device;

the VPN server receives packets whose transmission source address is a VPN address and destination address is an IP address of a file server by way of the gateway terminal device and then transfers these addresses to the file server;

after the packet is transferred to the file server, the VPN server receives packets from the file server whose transmission source address is the IP address of the file server, and whose destination address is one or more of the VPN addresses;

the VPN server encapsulates the packets by applying a header whose transmission source addresses are the IP addresses of the VPN server and destination addresses are global addresses of the gateway terminal device and at least one other terminal device not designated as the gateway terminal device;

the VPN server distributes the encapsulated packets to the gateway terminal device and the another terminal device according to global addresses which are destination addresses of headers of the packets;

the gateway terminal device and the another terminal device decapsulate the distributing packet;

then, the plurality of terminal devices transmit the encapsulated packets to the specific terminal device according to the VPN address which is the destination address of headers of the packets.

2. The packet routing control method according to claim 1 further including the following processes;

the VPN server assigns an unused IP address as a VPN address of the specific terminal device, wherein the unused IP address is assigned from an IP address group on the same subnet as that of the VPN addresses assigned to the plurality of terminal devices; and

the terminal device receives the VPN address of the specific terminal device assigned at the assignment from the VPN server.

3. The packet routing control method according to claim 1 further including following processes;

wherein the terminal device receives an IP address for the local network of the gateway terminal device from the VPN server;

and the gateway terminal device provides the IP address for local network to the specific terminal device as an IP address for a default gateway of the specific terminal device.

4. A packet routing control system, wherein a local network in which a plurality of terminal devices exist and a remote network in which a VPN server and a file server exist are VPN-connected wherein;

each of the plurality of terminal devices comprise;

a communication unit receiving a VPN address assigned to a specific terminal device from the VPN server and providing the VPN address to the specific terminal device;

a transmission unit wherein the distributed packets are decapsulated, the transmission unit transmitting the encapsulated packets to a plurality of other terminal devices according to global addresses which are destination address of headers of the packets;

the VPN server including;

a transfer unit transferring a packet whose transmission source address is a VPN address, and whose destination address is an IP address of the file server received from the specific terminal device to the file server by way of the terminal device;

a receiving unit receiving a packet whose transmission source address is a VPN address of the file server, and whose destination address is the VPN address of the specific terminal device from the file server after the file transfer;

an encapsulation unit encapsulating packets by applying a header whose transmission source address is the IP address of the VPN server and at least one other address is a global address of the terminal device and another terminal device that is not designated as a gateway among the plurality of terminal devices respectively;

the distribution unit distributing the encapsulated packets to the plurality of terminal devices according to global addresses which are destination addresses of headers of the encapsulated packets;

each of the plurality of terminal devices decapsulating the distributed packets;

the plurality of terminal devices then transmitting the encapsulated packets to the specific terminal device according to VPN addresses which are destination addresses of headers of the packets.

5. The packet routing control system according to claim 4 further comprising;

an assignment unit in which the VPN server assigns an unused IP address as a VPN address of the specific terminal device, wherein the unused IP address is assigned from the IP address group on the same subnet as that of the VPN address assigned to the plurality of terminal devices; and

the receiving unit wherein the terminal receives the VPN address of the specific terminal device is assigned at the assignment.

6. The packet routing control system according to claim 4,

wherein, when the gateway terminal device designates the specific terminal device, the terminal device receives an IP address regarding to communication device for the local network of the terminal device from the VPN server;

and

the terminal device provides the IP address regarding the communication device for the local network to the specific terminal device as an IP address for a default gateway of the specific terminal device.