Method and Apparatus for Communication of Data Packets between Local Networks
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Accused Products
Abstract
Method and arrangement for obtaining unambiguous addressing for data packets communicated between devices (E1B, E3A) in two different local networks (A,B) using potentially overlapping private IP address spaces. A VPN tunnel is initially established between gateways (102,104) in the two local networks and an internal IP address space is defined in each network for devices in the opposite network, not overlapping with an internal IP address space used for its own devices. When the gateway (102) of one network receives a data packet from a device (E1B) in the opposite network, the packet'"'"'s header is modified by changing the destination and source addresses, which belong to address spaces valid in the opposite network, into addresses belonging to address spaces valid in the present network.
34 Citations
55 Claims
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1-28. -28. (canceled)
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29. A method of communicating data packets between a first communications device in a first local network and a second communications device in a second local network, wherein potentially overlapping private IP addresses are used for devices in the first and second local networks, comprising:
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establishing a VPN (Virtual Private Network) tunnel between a first gateway serving the first local network and a second gateway serving the second local network, wherein a public IP address has been assigned to each gateway; defining, in the first gateway, a selected internal IP address space to be used in the first local network for devices in the second local network, the selected internal IP address space being separate from an internal IP address space used in the first local network for devices in the first local network; receiving, in the first gateway, an incoming data packet from the second device via said VPN tunnel, the incoming packet having an internal IP header including a first internal destination address used in the second local network for the first device and a first internal source address used in the second local network for the second device; changing the first internal destination address to a second internal destination address used in the first local network for the first device; changing the first internal source address to a second internal source address that is within the selected internal IP address space and is used in the first local network for the second device; and forwarding the incoming packet to the first device with a modified internal IP header including the changed second internal destination address and the changed second internal source address. - View Dependent Claims (30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41)
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42. An arrangement in a first gateway serving a first local network, configured for communicating data packets between a first communications device in the first local network and a second communications device in a second local network served by a second gateway, the first gateway being configured to establish a VPN tunnel between the first gateway and the second gateway, wherein a public IP address has been assigned to each gateway, and potentially overlapping private IP addresses are used for devices in each local network, said arrangement comprising:
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an IP address defining module configured to define a selected internal IP address space to be used in the first local network for devices in the second local network, the selected internal IP address space being separate from an internal IP address space used in the first local network for devices in the first local network; a receiving module configured to receive an incoming data packet from the second device via said VPN tunnel, the incoming packet having an internal IP header including a first internal destination address used in the second local network for the first device and a first internal source address used in the second local network for the second device; an IP address changing module configured to change the first internal destination address to a second internal destination address used in the first local network for the first device, and to change the first internal source address to a second internal source address that is within the selected internal IP address space and is used in the first local network for the second device; and a forwarding module configured to forward the incoming packet to the second device with a modified internal IP header including the changed second internal destination address and the changed second internal source address. - View Dependent Claims (43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54)
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55. A computer program configured for a first gateway that serves a first local network and is configured for communicating data packets between a first communications device in the first local network and a second communications device in a second local network served by a second gateway, wherein a VPN tunnel is established between the first gateway and the second gateway, a public IP address has been assigned to each gateway, and potentially overlapping private IP addresses are used for devices in each local network, and wherein the computer program is stored in a computer-readable medium and, when executed on the first gateway, causes the first gateway to:
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define a selected internal IP address space to be used in the first local network for devices in the second local network, the selected internal IP address space being separate from an internal IP address space used in the first local network for devices in the first local network; and when receiving from the second device via said VPN tunnel an incoming packet having an internal IP header including a first internal destination address used in the second local network for the first device and a first internal source address used in the second local network for the second device; change the first internal destination address to a second internal destination address used in the first local network for the first device; change the second internal source address to a second internal source address that is within the selected internal IP address space and is used in the first local network for the second device; and forward the incoming packet to the first device with a modified internal IP header including the changed second internal destination address and the changed second internal source address.
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Specification