Methods and apparatus for interfacing a computer or small network to a wide area network such as the internet

• US 6,157,950 A
• Filed: 12/05/1997
• Issued: 12/05/2000
• Est. Priority Date: 12/05/1997
• Status: Expired due to Fees

• Current Assignee: Encanto Networks
• Original Assignee: Encanto Networks, Inc.
• Inventors: Krishnan, Kalyan
• Primary Examiner(s): Rinehart, Mark H.
• Assistant Examiner(s): PIERCE, IVAN
• Application Number:
  US08/985,768
• Time in Patent Office: 1,096 Days
• Field of Search: 709/246, 709/245, 709/249, 709/223, 395/200.76, 395/200.75, 395/200.79
• US Class Current: 709/223
• CPC Class Codes: H04L 12/4604 LAN interconnection over a backbone network, e.g. Internet, Frame Relay
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

Methods and apparatus are provided for coupling a single computer, or small network of computers, and associated peripheral devices, to a wide area network, such as the Internet. The apparatus enables the devices to share a one or more IP addresses. The apparatus further enables remote access to the associated peripheral devices.

Claims

1. A method for communicating data between a first computer and a second computer, the method comprising:

accepting a first data packet from the first computer;

modifying a source field in the first data packet;

transmitting the modified first data packet to the second computer;

accepting a second data packet from the second computer, said second data packet being an HTTP request;

searching a table for a record correlating data in the source field of the first packet and in the destination field of the second packet;

if said searching is unsuccessful, examining the second data packet for a Uniform Resource Locator or Uniform Resourse Name to identify a destination of the second data packet;

modifying a destination field in the second data packet, where the destination field identifies the first computer; and

transmitting the modified second data packet to the first computer.

2. The method as defined in claim 1 further including a step of examining a destination field of the first data packet, wherein the destination field identifies the second computer.

3. The method as defined in claim 2 wherein the first data packet is received from the first computer via a first network, the method further including a step of determining if the second computer is attached to the first network and discarding the first data packet if the second computer is attached to the first network.

4. The method as defined in claim 3 wherein the second computer is attached to a second network, and the step of transmitting the first data packet comprises transmitting the first data packet to the second computer via the second network.

5. The method as defined in claim 4 wherein the source field includes an address of the first computer, and wherein the step of modifying the source field comprises replacing the address of the first computer in the source field with the address of a third computer.

6. The method as defined in claim 5 wherein the source field includes data identifying a process on the first computer that sent the first data packet, and wherein the step of modifying comprises replacing the process identifying data with data identifying a process on the third computer.

7. The method as defined in claim 5 further comprising a step of keeping a record correlating data in the source field, data in the modified source field, and data in the destination field.

8. The method as defined in claim 7 further comprising a step of storing the record.

9. The method as defined in claim 1 wherein the destination field includes data identifying a process on the third computer, and wherein the step of modifying comprises replacing the process identifying data with data identifying a process on the first computer.

10. The method as defined in claim 9 wherein, if the step of searching is successful, the step of modifying the second data packet further comprises replacing data in the destination field with data retrieved from a record found in the step of searching.

11. Apparatus for communicating data from a first computer to a second computer, the apparatus comprising:

a gateway computer having a first interface for communicating with the first computer and a second interface for communicating with the second computer; and

a processor programmed to accept a first data packet from the first computer via the first interface, modify a source field in the first data packet to form a modified first data packed, and then transmit the modified first data packet to the second computer via the second interface;

said processor is programmed to accept a second data packet from the second computer via the second interface, said second data packet being an HTTP request, modify a destination field in the second data packet to form a modified second data packet, the modified second data packet identifying the first computer, and then transmit the modified second data packet to the first computer via the first interface;

said processor is programmed to search a table for a record correlating data in the source field of the first packet and in the destination field of the second packet, and to examine the second data packet for a Uniform Resource Locator or Uniform Recourse Name to identify a destination of the second data packet if said search is unsuccessful.

12. The apparatus as defined in claim 11 wherein the processor is further programmed to examine a destination field of the first data packet that identifies the second computer.

13. The apparatus as defined in claim 12 wherein the first data packet is received from the first computer via a first network, and the processor is programmed to determine if the second computer is attached to the first network, the processor discarding the first data packet if the second computer is attached to the first network.

14. The apparatus as defined in claim 13 wherein the second computer is attached to a second network, and the processor is programmed to transmit the modified first data packet to the second computer via the second network.

15. The apparatus as defined in claim 14 wherein the source field includes an address of the first computer, and the processor is programmed to modify the source field by replacing the address of the first computer in the source field with an address of the gateway computer.

16. The apparatus as defined in claim 15 wherein the source field includes data identifying a process on the first computer that sent the first data packet, and the processor is programmed to modify the first data packet by replacing the data identifying the process on the first computer with data identifying a process on the gateway computer.

17. The apparatus as defined in claim 15 wherein the processor is programmed to keep a record correlating data in the source field of the first data packet, data in the source field of the modified data packet, and data in a destination field of the first packet.

18. The apparatus as defined in claim 17 wherein the processor is further programmed to store the record.

19. The apparatus as defined in claim 11 wherein the destination field of the second data packet includes an address of the gateway computer, and the processor is programmed to modify the destination field of the second packet by replacing the address of the gateway computer with an address of the first computer.

20. The apparatus as defined in claim 11 wherein the destination field includes data identifying a process on the gateway computer, and the processor is programmed to modify the data identifying a process in the gateway computer with data identifying a process on the first computer.

21. The apparatus as defined in claim 20 wherein the processor is programmed to replace data in the destination field of the second packet with data retrieved from a record found in the table if the search is successful.

22. A gateway for communicating data between a first computer and a second computer, comprising:

first interface for communicating with the first computer;

a second interface for communicating with the second computer; and

a circuit to accept a first data packet from the first computer via the first interface, modify a source field in the first data packet to form a modified first data packed, and then transmit the modified first data packet to the second computer via the second interface;

said circuit to accept a second data packet from the second computer via the second interface, said second data packet being an HTTP request, modify a destination field in the second data packet to form a modified second data packet, the modified second data packet identifying the first computer, and then transmit the modified second data packet to the first computer via the first interface;

said circuit to search a table for a record correlating data in the source field of the first packet and in the destination field of the second packet, and to examine the second data packet for a Uniform Resource Locator or Uniform Recourse Name to identify a destination of the second data packet if said search is unsuccessful.