Method and apparatus for eliminating use of a transfer protocol on a proxied connection

• US 6,598,081 B1
• Filed: 08/13/2001
• Issued: 07/22/2003
• Est. Priority Date: 07/31/1997
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Coile, Brantley W., Howes, Richard A., LeBlanc, William M.
• Primary Examiner(s): Najjar, Saleh
• Application Number:
  US09/929,825
• Time in Patent Office: 708 Days
• Field of Search: 709/227, 709/203, 709/219, 709/224, 709/228, 709/229
• US Class Current: 709/227
• CPC Class Codes: H04L 1/16 in which the return channel carries supervisory signals, e.g. repetition request signals
• CPC Class Codes: H04L 2001/0092 Error control systems characterised by the topology of the transmission link
• CPC Class Codes: H04L 67/01 Protocols
• 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 69/163 In-band adaptation of TCP data exchange; In-band control procedures
• CPC Class Codes: H04L 69/326 in the transport layer [OSI layer 4] H04L69/16 takes precedence
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A method for eliminating use of a transfer protocol on a proxied connection includes deriving a client originated packet sequence synchronization factor and a server originated packet sequence synchronization factor. The method further includes adjusting a client originated data acknowledgement number and a client originated data sequence number based on the client originated packet sequence synchronization factor, and adjusting a server originated data sequence number and a server originated data acknowledgement number based on the server originated packet sequence synchronization factor. The method also includes initiating a non-participating application that is not participating in the transfer protocol.

Claims

1. A method of bypassing a participating application that receives data from a client connection between a proxy and a client and receives data from a server connection between a proxy and a server comprising:

deriving a client originated packet sequence synchronization factor, the client originated packet sequence synchronization factor being derived from a difference between a last data sequence number sent by a participating application to a server and a last data acknowledgment number sent by the participating application to a client, wherein the participating application participates in a transport protocol;

deriving a server originated packet sequence synchronization factor, the server originated packet sequence synchronization factor being derived from a difference between a last data sequence number sent by the participating application to the client and a last data acknowledgment number sent by the participating application to the server;

adjusting a server originated data sequence number of a packet sent from the server to the client using the server originated packet sequence synchronization factor;

adjusting a client originated data acknowledgment number of a packet sent from the client to the server using the server originated packet sequence synchronization factor;

adjusting a client originated data sequence number of a packet sent from the client to the server using the client originated packet sequence synchronization factor;

adjusting a server originated data acknowledgment number of a packet sent from the server to the client using the client originated packet sequence synchronization factor;

whereby data sequence and acknowledgment numbers are synchronized between the client and the server; and

initiating a non-participating application operable to communicate data between the client and the server, wherein the non-participating application does not participate in the transport protocol and wherein the non-participating application is operable to communicate data using the client originated packet sequence synchronization factor and the server originated packet sequence synchronization factor.

2. A method as recited in claim 1 wherein the data is received by the non-participating application in the form of incoming data packets and the incoming data packets are not acknowledged by the non-participating application.

3. A method as recited in claim 1 wherein the data is received by the non-participating application in the form of incoming data packets and the checksum of the incoming data packets is not checked.

4. A method as recited in claim 1 wherein the data is received by the non-participating application in the form of incoming data packets, the data packets including packet headers having data checksums and IP checksums and wherein the data checksums and IP checksums are incremented and not checked by the non-participating application.

5. A method as recited in claim 1 further including defining a connection object including a quad, the quad including a client IP address, a server IP address, a client port number, and a server port number wherein the data is received in the form of incoming data packets, the data packets including packet headers, and the connection object is used to modify the packet headers.

6. A method as recited in claim 5 wherein the connection object further includes a client originated packet sequence synchronization factor and a server originated packet sequence synchronization factor wherein the client originated packet sequence synchronization factor is derived from the difference between the last data sequence number sent by the participating application to the server and the last data acknowledgment number sent by the participating application to the client and the server originated packet sequence synchronization factor is derived from the difference between the last data sequence number sent by the participating application to the client and the last data acknowledgment number sent by the participating application to the server.

7. The method of claim 1, wherein the transport protocol comprises Transmission Control Protocol.

8. A computer program product for unproxying a connection between a client and a server, the computer program product being embodied in a computer readable medium and comprising computer instructions for generating a connection object, the connection object comprising:

a quad, the quad including a client IP address, a server IP address, a client port number, and a server port number;

a client originated packet sequence synchronization factor, the client originated packet sequence synchronization factor being derived from a difference between a last data sequence number sent by a participating application, wherein the participating application participates in a transport protocol, to a server and a last data acknowledgment number sent by the participating application to a client; and

a server originated packet sequence synchronization factor, the server originated packet sequence synchronization factor being derived from a difference between a last data sequence number sent by the participating application to the client and a last data acknowledgment number sent by the participating application to the server;

wherein the connection object is suitable for modifying packet headers in packets relayed between the client and the server and wherein the connection object is suitable for communicating data between the client and the server without participating in the transport protocol.

9. The computer program product of claim 8, wherein the connection object is configured to modify the packet headers by adjusting a server originated data sequence number of a packet sent from the server to the client using the server originated packet sequence synchronization factor.

10. The computer program product of claim 8, wherein the connection object is configured to modify the packet headers by adjusting a client originated data acknowledgement number of a packet sent from the client to the server using the server originated packet sequence synchronization factor.

11. The computer program product of claim 8, wherein the connection object is configured to modify the packet headers by adjusting a client originated data sequence number of a packet sent from the client to the server using the client originated packet sequence synchronization factor.

12. The computer program product of claim 8, wherein the connection object is configured to modify the packet headers by adjusting a server originated data acknowledgment number of a packet sent from the server to the client using the client originated packet sequence synchronization factor.

13. The computer program product of claim 8, wherein the transport protocol comprises Transmission Control Protocol.

14. A computer program product for unproxying a connection between a client and a server, the computer program product being embodied in a computer readable medium and comprising computer instructions for:

deriving a client originated packet sequence synchronization factor, the client originated packet sequence synchronization factor being derived from a difference between a last data sequence number sent by a participating application, wherein the participating application participates in a transport protocol, to a server and a last data acknowledgment number sent by the participating application to a client;

deriving a server originated packet sequence synchronization factor being derived from a difference between a last data sequence number sent by the participating application to the client and a last data acknowledgment number sent by the participating application to the server;

adjusting a server originated data sequence number of a packet sent from the server to the client using the server originated packet sequence synchronization

adjusting a client originated data acknowledgment number of a packet sent from the client to the server using the server originated packet sequence synchronization factor;

adjusting a client originated data sequence number of a packet sent from the client to the server using the client originated packet sequence synchronization factor; and

adjusting a server originated data acknowledgment number of a packet sent from the server to the client using the client originated packet sequence synchronization factor; and

initiating a non-participating application to communicate data between the client and the server, wherein the non-participating application does not participate in the transport protocol and wherein the non-participating application communicates the data using the server originated data sequence number, the client originated data acknowledgment, the client originated data sequence number, and the server originated data acknowledgment number.

15. The computer program product of claim 14, wherein the transport protocol comprises Transmission Control Protocol.

16. The computer program product of claim 14, wherein the data is received by the non-participating application in the form of incoming data packets and the incoming data packets are not acknowledged by the non-participating application.

17. The computer program product of claim 14, wherein the data is received by the non-participating application in the form of incoming data packets and the checksum of the incoming data packets is not checked.

18. The computer program product of claim 14, wherein the data is received by the non-participating application in the form of incoming data packets, the data packets including packet headers having data checksums and IP checksums and wherein the data checksums and IP checksums are incremented and not checked by the non-participating application.

19. The computer program product of claim 14, the computer program product further comprising instructions for defining a connection object including a quad, the quad including a client IP address, a server IP address, a client port number, and a server port number wherein the data is received in the form of incoming data packets, the data packets including packet headers, and the connection object is used to modify the packet headers.

20. A system for unproxying a connection between a client and a server, the system comprising:

a processor configured to execute computer instructions;

a first network connection to a client;

a second network connection to a server; and

memory associated with the processor and configured to store computer instructions executable by the processor, the computer instructions comprising computer instructions for;

deriving a client originated packet sequence synchronization factor, the client originated packet sequence synchronization factor being derived from a difference between a last data sequence number sent by a participating application to the server, wherein the participating application participates in a transport protocol, and a last data acknowledgment number sent by the participating application to the client;

deriving a server originated packet sequence synchronization factor, the server originated packet sequence synchronization factor being derived from a difference between a last data sequence number sent by the participating application to the client and a last data acknowledgment number sent by the participating application to the server;

adjusting a server originated data sequence number of a packet sent from the server to the client using the server originated packet sequence synchronization factor;

adjusting a client originated data acknowledgment number of a packet sent from the client to the server using the server originated packet sequence synchronization factor;

adjusting a client originated data sequence number of a packet sent from the client to the server using the client originated packet sequence synchronization factor;

adjusting a server originated data acknowledgment number of a packet sent from the server to the client using the client originated packet sequence synchronization factor; and

initiating a non-participating application to communicate data between the client and the server, wherein the non-participating application does not participate in the transport protocol and wherein the non-participating application communicates the data using the server originated data sequence number, the client originated data acknowledgment, the client originated data sequence number, and the server originated data acknowledgment number.

21. The system of claim 20, wherein the transport protocol comprises Transmission Control Protocol.

22. The system of claim 20, wherein the data is received by the non-participating application in the form of incoming data packets and the incoming data packets are not acknowledged by the non-participating application.

23. The system of claim 20, wherein the data is received by the non-participating application in the form of incoming data packets and the checksum of the incoming data packets is not checked.

24. The system of claim 20, wherein the data is received by the non-participating application in the form of incoming data packets, the data packets including packet headers having data checksums and IP checksums and wherein the data checksums and IP checksums are incremented and not checked by the non-participating application.

25. The system of claim 20, the computer instructions further comprising computer instructions for defining a connection object including a quad, the quad including a client IP address, a server IP address, a client port number, and a server port number wherein the data is received in the form of incoming data packets, the data packets including packet headers, and the connection object is used to modify the packet headers.

26. A system for unproxying a connection between a client and a server, the system comprising:

means for deriving a client originated packet sequence synchronization factor, the client originated packet sequence synchronization factor being derived from a difference between a last data sequence number sent by a participating application, wherein the participating application participates in a transport protocol, to a server and a last data acknowledgment number sent by the participating application to a client;

means for deriving a server originated packet sequence synchronization factor, the server originated packet sequence synchronization factor being derived from a difference between a last data sequence number sent by the participating application to the client and a last data acknowledgment number sent by the participating application to the server;

means for adjusting a server originated data sequence number of a packet sent from the server to the client using the server originated packet sequence synchronization factor;

means for adjusting a client originated data acknowledgment number of a packet sent from the client to the server using the server originated packet sequence synchronization factor;

means for adjusting a client originated data sequence number of a packet sent from the client to the server using the client originated packet sequence synchronization factor; and

means for adjusting a server originated data acknowledgment number of a packet sent from the server to the client using the client originated packet sequence synchronization factor; and

means for initiating a non-participating application to communicate data between the client and the server, wherein the non-participating application does not participate in the transport protocol and wherein the non-participating application communicates the data using the server originated data sequence number, the client originated data acknowledgment, the client originated data sequence number, and the server originated data acknowledgment number.

27. The system of claim 26, wherein the transport protocol comprises Transmission Control Protocol.

28. The system of claim 26, wherein the data is received by the non-participating application in the form of incoming data packets and the incoming data packets are not acknowledged by the non-participating application.

29. The system of claim 26, wherein the data is received by the non-participating application in the form of incoming data packets and the checksum of the incoming data packets is not checked.

30. The system of claim 26, wherein the data is received by the non-participating application in the form of incoming data packets, the data packets including packet headers having data checksums and IP checksums and wherein the data checksums and IP checksums are incremented and not checked by the non-participating application.

31. The system of claim 26, further comprising means for defining a connection object including a quad, the quad including a client IP address, a server IP address, a client port number, and a server port number wherein the data is received in the form of incoming data packets, the data packets including packet headers, and the connection object is used to modify the packet headers.