TCP proxy connection management in a gigabit environment

• US 7,328,267 B1
• Filed: 05/02/2002
• Issued: 02/05/2008
• Est. Priority Date: 01/18/2002
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Patra, Abhijit, Bashyam, Murali, Finn, Norman W.
• Primary Examiner(s): VU, THONG H
• Application Number:
  US10/137,628
• Time in Patent Office: 2,105 Days
• Field of Search: 709/203, 709223-230, 709/240, 709/213, 709/217, 455/435, 718/105
• US Class Current: 709/227
• CPC Class Codes: H04L 69/12 Protocol engines
• 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 69/165 Combined use of TCP and UDP protocols; selection criteria therefor

Abstract

The present invention describes a method and apparatus to effectively manage data buffers for a client and a server connection in a multiple connection environment. The TCP processes of servers and clients are merged into an independent TCP process in a TCP ‘proxy’ server. The TCP proxy server includes a control unit and a data switching unit (the proxy application). The TCP proxy server terminates the client TCP connection and initiates a separate TCP connection with the server. The data switching unit binds the two individual connections. The TCP proxy server portrays the actual server TCP. The control unit in the TCP proxy server manages data buffers, control memory and supports multiple connections. The control unit ‘pushes’ the data into the buffers by monitoring the use of the buffers. The control unit does not wait for data requests from the data switching unit thus, eliminating the overhead of data request messages.

Claims

1. A method comprising:

managing a control memory of a network element, wherein

said control memory is used in managing a first Transmission Control Protocol (TCP) connection,

said network element is communicatively coupled to a first network element via a second TCP connection,

said network element is communicatively coupled to a second network element via said first TCP connection, and

said managing comprises

identifying a plurality of parameters for said first TCP connection;

populating said plurality of parameters into a plurality of control memory entries in said control memory; and

releasing said plurality of control memory entries in a plurality of states of said first TCP connection.

2. The method of claim 1, wherein

said network element comprises a TCP proxy server,

said first network element comprises a client,

said second network element comprises a server, and

said method is performed by said TCP proxy server.

3. The method of claim 2, further comprising:

identifying a first subset of parameters needed for processing said first TCP connection in a TIME_WAIT state from said plurality of parameters.

4. The method of claim 3, further comprising:

populating said first subset of parameters in a field entry of said control memory.

5. The method of claim 4, further comprising:

populating remaining parameters of said plurality of parameters in a control block entry of said control memory.

6. The method of claim 5, further comprising;

monitoring said plurality of states of said first TCP connection.

7. The method of claim 6, further comprising:

if said first TCP connection is in said TIME_WAIT state,

releasing said control block entry of said control memory.

8. The method of claim 7, further comprising:

using a flow entry to process said first TCP connection in said TIME_WAIT state.

9. The method of claim 7, further comprising:

initiating a timer.

10. The method of claim 9, wherein said timer is a 60 second timer.

11. The method of claim 10, further comprising:

determining whether said timer has expired.

12. The method of claim 11, further comprising:

if said timer has expired,

releasing a flow entry of said control memory.

13. The method of claim 11, further comprising:

if said timer has not expired,

determining if said first TCP connection is closed.

14. The method of claim 13, further comprising:

if said first TCP connection is closed,

releasing a flow entry of said control memory.

15. The method of claim 1, further comprising:

facilitating communications between said first network element and said second network element by maintaining the contents of a data buffer, wherein

data communicated between said first and said second network elements is transferred between said first and said second TCP connections via said data buffer, and

said managing said control memory of said network element comprises using said parameters in said control memory to control writing of data to and reading of said data from said buffer by said first and said second TCP connection such that an amount of said data maintained in said buffer is sufficient to satisfy an amount of data needed to satisfy a data requirement of said second TCP connection.

16. A network element comprising:

a control memory; and

a processor, wherein

said network element is communicatively coupled to a first network element via a second Transmission Control Protocol (TCP) connection,

said network element is communicatively coupled to a second network element via said first TCP connection, and

said processor is configured to manage said first TCP connection by virtue of being configured to

identify a plurality of parameters for a first TCP connection,

populate said plurality of parameters into a plurality of control memory entries in said control memory, and

release said plurality of control memory entries in a plurality of states of said first TCP connection.

17. The network element of claim 16, wherein

said network element comprises a TCP proxy server,

said first network element comprises a client,

said second network element comprises a server, and

said method is performed by said TCP proxy server.

18. The network element of claim 16, wherein said processor is further configured to

identify a first subset of parameters needed for processing said first TCP connection in a TIME_WAIT state from said plurality of parameters.

19. The network element of claim 18, wherein said processor is further configured to

populate said first subset of parameters in a field entry of said control memory.

20. The network element of claim 19, wherein said processor is further configured to

populate remaining parameters of said plurality of parameters in a control block entry of said control memory.

21. The network element of claim 20, wherein said processor is further configured to

monitor said plurality of states of said first TCP connection.

22. The network element of claim 21, wherein said processor is further configured to

if said first TCP connection is in said TIME_WAIT state,

release said control block entry of said control memory.

23. The network element of claim 22, wherein said processor is further configured to

use a flow entry to process said first TCP connection in said TIME_WAIT state.

24. The network element of claim 23, wherein said processor is further configured to

initiate a timer.

25. The network element of claim 24, wherein said timer is a 60 second timer.

26. The network element of claim 25, wherein said processor is further configured to

determine whether said timer has expired.

27. The network element of claim 26, wherein said processor is further configured to

if said timer has expired,

release a flow entry of said control memory.

28. The network element of claim 26, wherein said processor is further configured to

if said timer has not expired,

determine if said first TCP connection is closed.

29. The network element of claim 28, wherein said processor is further configured to

if a first TCP connection is closed,

release said flow entry of said control memory.

30. The network element of claim 16, wherein said processor is further configured to manage said first TCP connection by virtue of being configured to

facilitate communications between said first network element and said second network element by maintaining the contents of a data buffer, wherein

data communicated between said first and said second network elements is transferred between said first and said second TCP connections via said data buffer, and

said managing said control memory of said network element comprises using said parameters in said control memory to control writing of data to and reading of said data from said buffer by said first and said second TCP connection such that an amount of said data maintained in said buffer is sufficient to satisfy an amount of data needed to satisfy a data requirement of said second TCP connection.

31. A computer program product encoded in computer readable media, said program product comprising a set of instructions executable on a network element, said set of instructions configured to

identify a plurality of parameters for a first Transmission Control Protocol (TCP) connection, wherein

said network element is communicatively coupled to a first network element via a second TCP connection, and

said network element is communicatively coupled to a second network element via said first TCP connection;

populate said plurality of parameters into a plurality of control memory entries of a control memory, wherein

said control memory is used in managing said first TCP connection; and

release said plurality of control memory entries in a plurality of states of said first TCP connection.

32. The computer program product of claim 31, wherein

said network element comprises a TCP proxy server,

said first network element comprises a client,

said second network element comprises a server, and

said set of instructions are executed said TCP proxy server.

33. The computer program product of claim 31, wherein said set of instructions is further configured to

identify a first subset of parameters needed for processing said first TCP connection in a TIME_WAIT state from said plurality of parameters.

34. The computer program product of claim 33, wherein said set of instructions is further configured to

populate said first subset of parameters in a field entry of said control memory.

35. The computer program product of claim 34, wherein said set of instructions is further configured to

populate remaining parameters of said plurality of parameters in a control block entry of said control memory.

36. The computer program product of claim 35, wherein said set of instructions is further configured to

monitor said plurality of states of said first TCP connection.

37. The computer program product of claim 36, wherein said set of instructions is further configured to

if said first TCP connection is in said TIME_WAIT state,

release said control block entry of said control memory.

38. The computer program product of claim 37, wherein said set of instructions is further configured to

use a flow entry to process said first TCP connection in said TIME_WAIT state.

39. The computer program product of claim 37, wherein said set of instructions is further configured to

initiate a timer.

40. The computer program product of claim 39, wherein said timer is a 60 second timer.

41. The computer program product of claim 40, wherein said set of instructions is further configured to

determine whether said timer has expired.

42. The computer program product of claim 41, wherein said set of instructions is further configured to

if said timer has expired,

release a flow entry of said control memory.

43. The computer program product of claim 41, wherein said set of instructions is further configured to

if said timer has not expired,

determine if said first TCP connection is closed.

44. The computer program product of claim 43, wherein said set of instructions is further configured to

if said first TCP connection is closed,

release said flow entry of a control memory.

45. The computer program product of claim 31, wherein said set of instructions are further configured to

facilitate communications between said first network element and said second network element by maintaining the contents of a data buffer, wherein

data communicated between said first and said second network elements is transferred between said first and said second TCP connections via said data buffer, and

said managing said control memory of said network element comprises using said parameters in said control memory to control writing of data to and reading of said data from said buffer by said first and said second TCP connection such that an amount of said data maintained in said buffer is sufficient to satisfy an amount of data needed to satisfy a data requirement of said second TCP connection.

46. A network element comprising:

means for identifying a plurality of parameters for a first Transmission Control Protocol (TCP) connection, wherein

said network element is communicatively coupled to a first network element via a second TCP connection, and

said network element is communicatively coupled to a second network element via said first TCP connection;

a control memory, wherein

said control memory comprises a plurality of control memory entries, and

said control memory comprises means for managing said first TCP connection;

means for populating said plurality of parameters into said control memory entries, wherein

said means for populating is coupled to said means for identifying and said control memory; and

means for releasing said control memory entries in a plurality of states of said first TCP connection, wherein

said means for releasing is coupled to said control memory.

47. The network element of claim 46, wherein

said network element comprises a TCP proxy server

said first network element comprises a client, and

said second network element comprises a server.

48. The network element of claim 46, further comprising:

means for identifying a first subset of parameters needed for processing said first TCP connection in a TIME_WAIT state from said plurality of parameters.

49. The network element of claim 48, further comprising:

means for populating said first subset of parameters in a field entry of said control memory.

50. The network element of claim 49, further comprising:

means for populating remaining parameters of said plurality of parameters in a control block entry of said control memory.

51. The network element of claim 50, further comprising;

means for monitoring said plurality of states of said first TCP connection.

52. The network element of claim 51, further comprising:

means for releasing said control block entry of said control memory if said first TCP connection is in said TIME_WAIT state.

53. The network element of claim 52, further comprising:

means for using a flow entry to process said first TCP connection in said TIME_WAIT state.

54. The network element of claim 52, further comprising:

means for initiating a timer.

55. The network element of claim 54, wherein said timer is a 60 second timer.

56. The network element of claim 55, further comprising:

means for determining whether said timer has expired.

57. The network element of claim 56, further comprising:

means for releasing said flow entry of said control memory if said timer has expired.

58. The network element of claim 56, further comprising:

means for determining if said first TCP connection is closed if said timer has not expired.

59. The network element of claim 58, further comprising:

means for releasing a flow entry of said control memory if said first TCP connection is closed.

60. The network element of claim 46, wherein

means for facilitating communications between said first network element and said second network element comprising means for maintaining the contents of a data buffer, wherein

data communicated between said first and said second network elements is transferred between said first and said second TCP connections via said data buffer, and

said means for managing said control memory of said network element comprises means for using said parameters in said control memory to control means for writing of data to and means for reading of said data from said buffer by said first and said second TCP connection such that an amount of said data maintained in said buffer is sufficient to satisfy an amount of data needed to satisfy a data requirement of said second TCP connection.