Nomadic translator or router

• US 6,130,892 A
• Filed: 03/12/1998
• Issued: 10/10/2000
• Est. Priority Date: 03/12/1997
• Status: Expired due to Term

• Current Assignee: Nomadix, Inc. (Nippon Telegraph and Telephone Corporation)
• Original Assignee: Nomadix, Inc. (Nippon Telegraph and Telephone Corporation)
• Inventors: Kleinrock, Leonard, Short, Joel E.
• Primary Examiner(s): Ngo, Ricky
• Assistant Examiner(s): NGUYEN, STEVEN H D
• Application Number:
  US09/041,534
• Time in Patent Office: 943 Days
• Field of Search: 370/338, 370/389, 370/390, 370/392, 370/393, 370/395, 370/397, 370/400, 370/401, 370/402, 370/404, 370/406, 370/409, 370/465, 370/463, 370/466, 370/467, 370/350, 370/252 , 370/254, 370/255, 370/408, 455/432, 455/433, 455/456, 340/825.07, 340/825.2, 340/825.21, 709/220, 709/221, 709/222, 709/223, 709/219, 709/226, 709/229, 709/230, 709/245
• US Class Current: 370/401
• CPC Class Codes: H04L 41/0806 for initial configuration or provisioning, e.g. plug-and-play
• CPC Class Codes: H04L 41/0886 Fully automatic configuration
• 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 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/10 of different types
• CPC Class Codes: H04L 61/25 of the same type
• CPC Class Codes: H04L 61/5014 using dynamic host configuration protocol [DHCP] or bootstrap protocol [BOOTP]
• CPC Class Codes: H04L 61/5084 Providing for device mobility network addressing or numbering for mobility support in wireless networks H04W8/26; mobile IP H04W80/04
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04W 8/04 Registration at HLR or HSS [Home Subscriber Server]
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]
• CPC Class Codes: H04W 84/005 Moving wireless networks
• CPC Class Codes: H04W 88/182 Network node acting on behalf of an other network entity, e.g. proxy

Abstract

A nomadic router or translator enables a laptop computer or other portable terminal which is configured to be connected to a home network to be connected to any location on the internet or other digital data communication system. The router automatically and transparently re-configures the terminal to its new location and processes outgoing and incoming data. The router includes a processor which appears as the home network to the terminal, and appears as the terminal to the communication system. The terminal has a permanent address, the router has a router or translator address, and the terminal transmits outgoing data to the system including the permanent address as a source address. The processor translates the outgoing data by replacing the permanent address with the router address as the source address. The terminal receives incoming data from the system including the router address as a destination address, and the processor translates the incoming data by replacing the router address with the permanent address as the destination address. Alternatively, the terminal can be directly connected to a point on a local network, and the router connected to another point on the network. The router can be employed to implement numerous applications including nomadic e-mail, network file synchronizer, database synchronizer, instant network, nomadic internet and trade show router and can also be utilized as a fixed nomadic router.

Claims

1. A method for allowing network communications over a foreign network for a user device configured to communicate with a home network, the method comprising:

connecting the user device to the foreign network;

intercepting packets transmitted from the user device which would otherwise be dropped by devices on the foreign network to determine without requiring prior knowledge of network settings of the user device;

using the determined network settings of the user device to determine whether to intercept subsequently transmitted packets; and

automatically modifying packets transmitted from the user device based on the network settings of the user device and network settings of the foreign network.

2. The method of claim 1 wherein intercepting packets comprises:

intercepting an Address Resolution Protocol (ARP) packet transmitted from the user device to a network address on the home network; and

replying to the ARP packet using the network address of the home device and a hardware address of a configuration translator such that subsequent packets generated by the user device are sent to the configuration translator.

3. The method of claim 1 wherein intercepting packets comprises:

operating in a promiscuous mode to intercept all packets without regard to a packet destination address; and

determining the network settings of the user device based on a source address and destination addresses of the packets.

4. The method of claim 1 wherein intercepting packets comprises:

intercepting a Dynamic Host Control Protocol (DHCP) packet transmitted from the user device; and

replying to the DHCP packet to provide configuration settings based on the foreign network configuration.

5. The method of claim 1 wherein modifying packets transmitted from the user device comprises:

replacing a source address with a router address where the router address is automatically determined based on the network settings of the foreign network.

6. The method of claim 5 wherein replacing the source address comprises replacing a source address within a packet header.

7. The method of claim 5 wherein replacing the source address comprises replacing a source address within a packet header and a source address within packet contents.

8. The method of claim 5 further comprising:

receiving data from the foreign network with the router address as a destination address; and

replacing the destination address with a network address of the user device.