Method and apparatus for tunneling information

• US 7,260,650 B1
• Filed: 11/28/2001
• Issued: 08/21/2007
• Est. Priority Date: 11/28/2001
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Lueckenhoff, Bruce Arthur
• Primary Examiner(s): Jaroenchonwanit; Bunjob
• Assistant Examiner(s): DOAN, DUYEN MY
• Application Number:
  US09/995,920
• Time in Patent Office: 2,092 Days
• Field of Search: 709245-246, 714/52.4, 713151-152
• US Class Current: 709/246
• 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 69/166 IP fragmentation; TCP segmentation
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers

Abstract

The invention is directed to techniques and mechanisms, used in a beginning tunneling device, for detecting an initial request, identifying the initial request as a candidate to be a tunneling request, modifying at least one indicator of an initial header in the initial request to convert the initial request into the tunneling request, and forwarding the tunneling request towards an end tunneling device. The invention is also directed to techniques and mechanisms in an end tunneling device for detecting a tunneling request, identifying the tunneling request as a candidate to be an initial request, modifying at least one indicator of a tunneling header in the tunneling request to convert the tunneling request into the initial request, and forwarding the initial request towards a destination device. The embodiments of the invention add little or no packet overhead.

Claims

1. In a beginning tunneling device, a method of communication comprising the steps of:

detecting an initial request at the beginning tunneling device;

identifying the initial request as a candidate to be converted to a tunneling request wherein the identifying further comprises at least one of detecting that a destination address in the initial request is for a destination device associated with an end tunneling device, identifying any initial request received that has a particular source address as being designated to become a tunneling request, and interpreting information from an initial header in order to identify that the initial request is intended to be a tunneling request;

modifying at least one indicator of an initial header in the initial request to convert the initial request into the tunneling request, said modifying including specifying a destination code within a tunneling header for at least one of a plurality of destination addresses of destination devices served by an end tunneling device;

wherein the initial request received by the beginning tunneling device is in the format of a TCP/IP protocol and wherein the specifying comprises steps of;

generating a destination code to designate a destination address served by the end tunneling device; and

storing the destination code in a fragment offset field of an IP header of the tunneling request;

said modifying further includes setting an error correction code in the tunneling header to reflect modifications made to convert the initial header to the tunneling header and forwarding the tunneling request towards the end tunneling device.

2. The method of claim 1 wherein the step of modifying comprises the step of:

setting a protocol indicator in the initial header to a value indicating that the initial request is a tunneling request.

3. The method of claim 1 wherein the step of modifying comprises the step of:

replacing a destination address of a destination device in the initial header with an end tunneling address of an end tunneling device to produce a tunneling header.

4. The method of claim 1 wherein the initial request received by the beginning tunneling device is in the format of a TCP/IP protocol and wherein the step of modifying comprises the step of:

setting a protocol indicator in the initial header to a value indicating that the initial request is a tunneling request.

5. The method of claim 1 wherein the initial request and the tunneling request are the same size.

6. The method of claim 5 wherein the initial request and the tunneling request include respective initial headers and tunneling headers of the same size.

7. The method of claim 1 wherein the initial request is a full initial request and wherein the full initial request can be fully converted into a single tunneling request.

23. The method of claim 1 further comprising modifying a payload of the initial request to convert the initial request to a tunneling request.

8. In an end tunneling device, a method of communication comprises steps of:

detecting a tunneling request;

identifying the tunneling request as a candidate to be converted to an initial request;

modifying at least one indicator of a tunneling header in the tunneling request to convert the tunneling request into the initial request;

said modifying including obtaining a destination code within the tunneling header for at least one of a plurality of destination addresses of destination devices served by the end tunneling device;

wherein the tunneling request received by the end tunneling device is in the format of a TCP/IP protocol and wherein the obtaining comprises steps of;

reading a destination code from a fragment offset filed of an IP header of the tunneling request; and

from the destination code, ascertaining the destination address served by the end tunneling device;

replacing an end tunneling address of the end tunneling device in the tunneling header with the destination address to produce an initial header;

said modifying further includes setting an error correction code in the initial header to reflect modifications made to convert tunneling header to the initial header;

forwarding the initial request toward a destination device.

9. The method of claim 8 wherein the step of modifying comprises the step of:

setting a protocol indicator obtained from the tunneling header to a value to convert the tunneling request to an initial request.

10. The method of claim 8 wherein the tunneling request received by the end tunneling device is in the format of a TCP/IP protocol and wherein the step of modifying comprises the steps of:

setting a protocol indicator obtained from the tunneling header to a value to convert the tunneling request to an initial request.

24. The method of claim 8 further comprising modifying a payload of the initial request to convert the initial request to a tunneling request.

11. A beginning tunneling device for processing initial requests comprising:

a memory;

a communications interface;

a processor; and

an interconnection mechanism coupling the memory, the processor and the communications interface;

wherein the processor is configured to;

detect an initial request at the beginning tunneling device;

identify the initial request as a candidate to be converted to a tunneling request, wherein the identifying further comprises at least one of detecting that a destination address in the initial request is for a destination device associated with an end tunneling device, identifying any initial request received that has a particular source address as being designated to become a tunneling request, and interpreting information from an initial header in order to identify that the initial request is intended to be a tunneling request;

modifying at least one indicator of an initial header in the initial request to convert the initial request into the tunneling request, said modifying including specifying a destination code within a tunneling header for at least one of a plurality of destination addresses of destination devices served by an end tunneling device;

wherein the initial request received by the beginning tunneling device is in the format of a TCP/IP protocol and wherein the specifying comprises steps of;

generating a destination code to designate a destination address served by the end tunneling device; and

storing the destination code in a fragment offset field of an IP header of the tunneling request;

said modifying further includes setting an error correction code in the tunneling header to reflect modifications made to convert the initial header to the tunneling header and forwarding the tunneling request towards the end tunneling device.

12. The beginning tunneling device of claim 11 wherein, to modify at least one indicator, the beginning tunneling device is configured to:

set a protocol indicator in the initial header to a value indicating that the initial request is a tunneling request.

13. The beginning tunneling device of claim 11 wherein, to modify at least one indicator, the beginning tunneling device is configured to:

replace a destination address of a destination device in the initial header with an end tunneling address of an end tunneling device to produce a tunneling header.

14. The beginning tunneling device of claim 11 wherein the initial request received by the beginning tunneling device is in the format of a TCP/IP protocol and wherein, to modify at least one indicator, the beginning tunneling device is configured to:

set a protocol indicator in the initial header to a value indicating that the initial request is a tunneling request.

15. The beginning tunneling device of claim 11 wherein the initial request and the tunneling request are the same size.

16. The beginning tunneling device of claim 15 wherein the initial request and the tunneling request include respective initial headers and tunneling headers of the same size.

17. The beginning tunneling device of claim 11 wherein the initial request is a full initial request and wherein the full initial request can be fully converted into a single tunneling request.

18. An end tunneling device for processing tunneling requests comprising:

a memory;

a communications interface;

a processor; and

an interconnection mechanism coupling the memory, the processor and the communications interface;

wherein the processor is configured to;

detecting a tunneling request;

identifying the tunneling request as a candidate to be converted to an initial request;

modifying at least one indicator of a tunneling header in the tunneling request to convert the tunneling request into the initial request;

said modifying including obtaining a destination code within the tunneling header for at least one of a plurality of destination addresses of destination devices served by the end tunneling device;

wherein the tunneling request received by the end tunneling device is in the format of a TCP/IP protocol and wherein the obtaining comprises steps of;

reading a destination code from a fragment offset filed of an IP header of the tunneling request; and

from the destination code, ascertaining the destination address served by the end tunneling device;

replacing an end tunneling address of the end tunneling device in the tunneling header with the destination address to produce an initial header;

said modifying further includes setting an error correction code in the initial header to reflect modifications made to convert tunneling header to the initial header;

forwarding the initial request toward a destination device.

19. The end tunneling device of claim 18 wherein, to modify the at least one indicator, the end tunneling device is configured to:

set a protocol indicator obtained from the tunneling header to a value to convert the tunneling request to an initial request.

20. The end tunneling device of claim 18 wherein the tunneling request received by the end tunneling device is in the format of a TCP/IP protocol and wherein, to modify the at least one indicator, the end tunneling device is configured to:

set a protocol indicator obtained from the tunneling header to a value to convert the tunneling request to an initial request.

21. A computer program product that includes a computer readable medium having instructions stored thereon for conducting communications such that the instructions, when carried out by the computer, cause the computer to perform the steps of:

detecting an initial request;

identifying the initial request as a candidate to be converted to a tunneling request, wherein the identifying further comprises at least one of detecting that a destination address in the initial request is for a destination device associated with an end tunneling device, identifying any initial request received that has a particular source address as being designated to become a tunneling request, and interpreting information from an initial header in order to identify that the initial request is intended to be a tunneling request;

modifying at least one indicator of an initial header in the initial request to convert the initial request into the tunneling request, said modifying including specifying a destination code within a tunneling header for at least one of a plurality of destination addresses of destination devices served by an end tunneling device;

wherein the initial request received by the beginning tunneling device is in the format of a TCP/IP protocol and wherein the specifying comprises steps of;

generating a destination code to designate a destination address served by the end tunneling device; and

storing the destination code in a fragment offset field of an IP header of the tunneling request;

said modifying further includes setting an error correction code in the tunneling header to reflect modifications made to convert the initial header to the tunneling header and forwarding the tunneling request towards the end tunneling device.

22. A beginning tunneling device, for processing initial requests comprising:

a memory;

a communications interface;

a processor;

an interconnection mechanism coupling the memory, the processor and the communications interface;

means, coupled to the communications interface, for detecting an initial request;

means, coupled to the communications interface, for identifying the initial request as a candidate to be converted to a tunneling request,

wherein the means for identifying further comprises at least one of detecting that a destination address in the initial request is for a destination device associated with an end tunneling device, identifying any initial request received that has a particular source address as being designated to become a tunneling request, and interpreting information from an initial header in order to identify that the initial request is intended to be a tunneling request;

means, coupled to the communications interface, for modifying at least one indicator of an initial header in the initial request to convert the initial request in to the tunneling request, said modifying including specifying a destination code within a tunneling header for at least one of a plurality of destination addresses of destination devices served by an end tunneling device;

wherein the initial request received by the beginning tunneling device is in the format of a TCP/IP protocol and wherein the specifying comprises steps of;

generating a destination code to designate a destination address served by the end tunneling device; and

storing the destination code in a fragment offset field of an IP header of the tunneling request;

said modifying further includes setting an error correction code in the tunneling header to reflect modifications made to convert the initial header to the tunneling header and means coupled to the communication interface, for forwarding the tunneling request towards the end tunneling device.