System and method for network access without reconfiguration

• US 6,857,009 B1
• Filed: 10/23/2000
• Issued: 02/15/2005
• Est. Priority Date: 10/22/1999
• Status: Expired due to Term

• Current Assignee: Nomadix, Inc. (Nippon Telegraph and Telephone Corporation)
• Original Assignee: Nomadix, Inc. (Nippon Telegraph and Telephone Corporation)
• Inventors: Caswell, Ken, Ferreria, Manuel, Short, Joel E., Robbins, Barry R.
• Primary Examiner(s): Najjar, Saleh
• Assistant Examiner(s): Alam, Uzma
• Application Number:
  US09/694,577
• Time in Patent Office: 1,576 Days
• Field of Search: 709/219, 709/223, 709/224, 709/246, 709/200, 370/401, 370/475, 714/57
• US Class Current: 709/219
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/161 Implementation details of TCP/IP or UDP/IP stack architecture; Specification of modified or new header fields
• CPC Class Codes: H04L 69/163 In-band adaptation of TCP data exchange; In-band control procedures
• CPC Class Codes: H04L 69/166 IP fragmentation; TCP segmentation
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]

Abstract

A system and method for providing connectivity to a foreign network for a device configured for communication over a home network without reconfiguring the device include intercepting packets transmitted by the device, selectively modifying intercepted packets which are incompatible with the foreign network to be compatible with network settings of the foreign network, and selectively providing network services for the device corresponding to network services available on the home network to reduce the delay associated with accessing the network services from the foreign network, or to provide network services otherwise inaccessible from the foreign network. Network services are provided by or through a configuration adapter connected to the device or to the foreign network. The configuration adapter accommodates incompatibilities resulting from proxy server requests, domain name server requests, and/or outgoing email service requests to provide transparent network access for mobile users without reconfiguration of the users computing device.

Claims

1. A method for providing connectivity to a foreign network for a device having network settings configured for communication over a home network without reconfiguring the network settings of the device, the method comprising:

intercepting packets transmitted by the device;

selectively modifying intercepted packets which are incompatible with network settings configured for communication over the foreign network to be compatible with the network settings configured for communication over the foreign network, wherein the network settings configured for communication over the home and foreign networks include respective IP addresses, gateway addresses, subnet masks, DNS addresses, and protocol proxies; and

selectively providing network services for the device corresponding to network services available on the home network to reduce delay associated with accessing the network services from the foreign network, or to provide network services otherwise inaccessible from the foreign networks wherein selectively providing network services comprises providing a proxy service which includes resolving a domain name to an address;

wherein resolving a domain name to an address includes;

establishing a connection between the device and a configuration adapter in order for the configuration adapter to intercept packets transmitted by the device;

examining contents of the intercepted packets to identify a domain name;

resolving the domain name to an address;

establishing a connection between the configuration adapter and a computer at the address corresponding to the domain name; and

splicing the connections between the device and the configuration adapter, and between the configuration adapter and the computer, to form a single connection between the device and the computer such that the device and the computer communicate packets with each other over the single connection without the network settings of the device being reconfigured.

2. The method of claim 1 wherein the proxy service comprises a hypertext transfer protocol proxy service.

3. The method of claim 1 wherein the proxy service comprises a file transfer protocol proxy service.

4. The method of claim 1 wherein resolving a domain name to an address comprises:

attempting to resolve the domain name to an address using a domain name server accessible from the foreign network; and

resolving the domain name to an address corresponding to a configuration adapter after a predetermined timeout period expires, or if domain name servers accessible from the foreign network can not resolve the domain name.

5. The method of claim 1 wherein splicing the connections comprises directly modifying subsequently intercepted packets without copying the packet payload.

6. The method of claim 1 wherein resolving the domain name to an address comprises using a domain name server accessible from the foreign network.

7. The method of claim 1 wherein resolving the domain name to an address comprises:

resolving the domain name to an address using a domain name server;

attempting to establish a connection with the computer at the address corresponding to the domain name;

resolving the domain name to an address corresponding to the configuration adapter after expiration of a predetermined timeout period;

wherein the step of splicing is performed after receiving a delayed response from the computer at the address corresponding to the domain name.

8. The method of claim 1 wherein selectively providing network services comprises providing an outgoing email service.

9. The method of claim 8 wherein providing an outgoing email service comprises modifying intercepted simple mail transport protocol (SMTP) packets to redirect the intercepted SMTP packets to an SMTP server on the foreign network.

10. The method of claim 8 wherein providing an outgoing email service comprises modifying intercepted simple mail transport protocol (SMTP) packets to redirect the intercepted SMTP packets to an SMTP server on the foreign network without modifying the source address of the SMTP packet packets.

11. The method of claim 1 wherein selectively providing network services comprises redirecting domain name service requests to a local domain name server for the foreign network.

12. Apparatus for providing connectivity to a foreign network for a device having network settings configured for communication over a home network without reconfiguring the network settings of the device, the apparatus comprising:

means for intercepting packets transmitted by the device;

means for selectively modifying intercepted packets which are incompatible with network settings configured for communication over the foreign network to be compatible with the network settings of configured for communication over the foreign network, wherein the network settings configured for communication over the home and foreign networks include respective IP addresses, gateway addresses, subnet masks, DNS addresses, and protocol proxies; and

means for selectively providing network services for the device corresponding to network services available on the home network to reduce delay associated with accessing the network services from the foreign network, or to provide network services otherwise inaccessible from the foreign network;

wherein the means for selectively providing network services comprises means for providing a proxy service;

wherein the means for providing a proxy service comprises means for resolving a domain name to an address;

wherein the means for resolving a domain name to an address includes;

means for establishing a connection between the device and a configuration adapter in order for the configuration adapter to intercept packets transmitted by the device;

means for examining contents of the intercepted packets to identify a domain name;

means for resolving the domain name to an address;

means for establishing a connection between the configuration adapter and a computer at the address corresponding to the domain name; and

means for splicing the connections between the device and the configuration adapter, and between the configuration adapter and the computer, to form a single connection between the device and the computer such that the device and the computer communicate packets with each other over the single connection without the network settings of the device being reconfigured.

13. The apparatus of claim 12 wherein the proxy service comprises a hypertext transfer protocol proxy service.

14. The apparatus of claim 12 wherein the proxy service comprises a file transfer protocol proxy service.

15. The apparatus of claim 12 wherein the means for resolving a domain name to an address comprises:

means for attempting to resolve the domain name to an address using a domain name server accessible from the foreign network; and

means for resolving the domain name to an address corresponding to the configuration adapter after a predetermined timeout period expires, or if the domain name servers accessible from the foreign network can not resolve the domain name.

16. The apparatus of claim 12 wherein the means for splicing the connections comprises means for directly modifying subsequently intercepted packets without copying the packet payload.

17. The apparatus of claims 12 wherein the means for resolving the domain name to an address comprises means for using a domain name server accessible from the foreign network.

18. The apparatus of claim 12 wherein the means for resolving the domain name to an address comprises:

means for resolving the domain name to an address using a domain name server;

means for attempting to establish a connection with the computer at the address corresponding to the domain name;

means for resolving the domain name to an address corresponding to the configuration adapter after expiration of a predetermined timeout period;

wherein the means for splicing performs the splicing only after receiving a delayed response from the computer at the address corresponding to the domain name.

19. The apparatus of claim 12 wherein the means for selectively providing network services comprises means for providing an outgoing email service.

20. The apparatus of claim 19 wherein the means for providing an outgoing email service comprises means for modifying intercepted simple mail transport protocol (SMTP) packets to redirect the intercepted SMTP packets to an SMTP server on the foreign network.

21. The apparatus of claim 19 wherein the means for providing an outgoing email service comprises means for modifying intercepted simple mail transport protocol (SMTP) packets to redirect the intercepted SMTP packets to an SMTP server on the foreign network without modifying the source address of the SMTP packets.

22. The apparatus of claim 12 wherein the means for selectively providing network services comprises means for redirecting domain name service requests to a local domain name server for the foreign network to improve response time.

23. A configuration adapter for providing connectivity to a foreign network for a device having network settings configured for communication over a home network without reconfiguring the network settings of the device, the configuration adapter comprising:

at least one network interface for connecting to the foreign network; and

a processor in communication with the network interface, the processor intercepting packets transmitted by the device, selectively modifying intercepted packets which are incompatible with network settings configured for communication over the foreign network to be compatible with the network settings of configured for communication over the foreign network, and selectively providing network services for the device corresponding to network services available on the home network to reduce delay associated with accessing the network services from the foreign network, or to provide network services otherwise inaccessible from the foreign network;

wherein the network settings configured for communication over the home and foreign networks include respective IP addresses, gateway addresses, subnet masks, DNS addresses, and protocol proxies;

wherein the processor selectively provides a proxy service for the device which includes resolving a domain name to an address;

wherein the processor resolves a domain name to an address by establishing a connection between the device and the configuration adapter, examining contents of the intercepted packets to identify a domain name, resolving the domain name to an address, establishing a connection between the configuration adapter and a computer at the address corresponding to the domain name, and splicing the connections between the device and the configuration adapter, and between the configuration adapter and the computer, to form a single connection between the device and the computer such that the device and the computer communicate packets with each other over the single connection without the network settings of the device being reconfigured.

24. The configuration adapter of claim 23 wherein the proxy service comprises a hypertext transfer protocol proxy service.

25. The configuration adapter of claim 23 wherein the proxy service comprises a file transfer protocol proxy service.

26. The configuration adapter of claim 23 wherein the processor attempts to resolve the domain name to an address using a domain name server accessible from the foreign network, and resolves the domain name to an address corresponding to the configuration adapter after a predetermined timeout period expires, or if the domain name servers accessible from the foreign network can not resolve the domain name.

27. The configuration adapter of claim 23 wherein the processor splices the connections by directly modifying subsequently intercepted packets without copying the packet payload.

28. The configuration adapter of claim 23 wherein the processor resolves the domain name to an address using a domain name server accessible from the foreign network.

29. The configuration adapter of claim 23 wherein the processor resolves the domain name to an address by:

resolving the domain name to an address using a domain name server;

attempting to establish a connection with the computer at the address corresponding to the domain name;

resolving the domain name to an address corresponding to the configuration adapter after expiration of a predetermined timeout period; and

splicing the connections after receiving a delayed response from the computer at the address corresponding to the domain name.

30. The configuration adapter of claim 23 wherein the processor selectively provides an outgoing email service.

31. The configuration adapter of claim 30 wherein the processor provides an outgoing email service by redirecting intercepted simple mail transport protocol (SMTP) packets to an SMTP server configured to process mail from addresses on the foreign network.

32. The configuration adapter of claim 30 wherein the processor redirects intercepted simple mail transport protocol (SMTP) packets without modifying the source address of the SMTP packets.

33. The configuration adapter of claim 30 wherein the processor redirects domain name service requests to a local domain name server for the foreign network.

34. A method for providing access to a second local area network for a device configured to communicate over a first local area network having incompatible network settings with network settings of the second local area network, the method comprising:

determining whether an application running on the device is requesting a proxy service;

wherein the step of determining comprises;

establishing a transmission control protocol (TCP) connection between a configuration adapter and the device to examine contents of a packet transmitted by the device;

establishing a TCP connection between the configuration adapter and the proxy server requested by the application; and

splicing the connection such that end-to-end semantics are maintained by the application and the requested proxy server, and

modifying packets containing proxy requests to direct requests if the requested proxy service is inaccessible from the foreign network without modifying the network settings of the device.

35. The method of claim 34 wherein the step of splicing comprises:

implementing a subset of network protocol functionality to intercept each packet from the application without passing the packet through an RFC-compliant protocol stack.