Transport protocol connection synchronization

• US 20060262734A1
• Filed: 05/19/2005
• Published: 11/23/2006
• Est. Priority Date: 05/19/2005
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Ramaiah, Anantha, Appanna, Chandrashekhar
• Granted Patent: US 7,801,135 B2
• Time in Patent Office: Days
• US Class Current: 370/254
• CPC Class Codes: H04L 45/121 by minimising delays
• CPC Class Codes: H04L 69/14 Multichannel or multilink 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 69/161 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 69/326 in the transport layer [OSI layer 4] H04L69/16 takes precedence

Abstract

A system and method supporting synchronization of replicated transport layer connections in a redundant processor telecommunications network element. One method involves receiving, at a network element comprising an active transport protocol process coupled to a standby transport protocol process, information identifying a newly created transport layer connection maintained at the active transport protocol process; assigning a unique connection identifier to the transport layer connection; sending the unique connection identifier, in association with other, protocol-specific connection identifying information, to the standby protocol process; and sending, to the standby transport protocol process, one or more messages comprising one or more properties or statistics associated with the transport layer connection, wherein the messages identify the transport layer connection using the unique connection identifier.

Claims

1. A method, comprising:

receiving, at a router that hosts a master transmission control protocol (TCP) module coupled through an inter-process communication (IPC) facility to a slave TCP module, information identifying a newly created TCP connection maintained at the master TCP module;

assigning a unique connection identifier to the TCP connection;

sending the unique connection identifier, in association with a source address value, destination address value, source port value, and destination port value, to the slave TCP module;

sending, from the master TCP module to the slave TCP module over the IPC facility, one or more messages comprising one or more properties or statistics associated with the transport layer connection, wherein the messages identify the transport layer connection using the unique connection identifier, wherein the messages are not TCP segments;

notifying an application running on the TCP connection that the TCP connection is available.

2. A method as recited in claim 1, wherein the notifying comprises sending a message to a dedicated listener port.

3. A method as recited in claim 1, wherein the master TCP module receives one or more TCP segments, replicates the one or more TCP segments, and sends the replicated one or more TCP segments to the slave TCP module, wherein the slave TCP module sends the replicated one or more TCP segments through an input path of the slave TCP module to thereby replicate state data maintained by the master TCP module and associated with the one or more TCP segments.

4. A method, comprising:

receiving, at a network element comprising an active transport protocol process coupled to a standby transport protocol process, information identifying a newly created transport layer connection maintained at the active transport protocol process;

assigning a unique connection identifier to the transport layer connection;

sending the unique connection identifier, in association with other, protocol-specific connection identifying information, to the standby protocol process;

sending, to the standby transport protocol process, one or more messages comprising one or more properties or statistics associated with the transport layer connection, wherein the messages identify the transport layer connection using the unique connection identifier.

5. A method as recited in claim 4, wherein the messages conform to a specified transport protocol synchronization message format and are not TCP segments.

6. A method as recited in claim 4, wherein both the active transport protocol process and the standby transport protocol process implement TCP.

7. A method as recited in claim 4, wherein the protocol-specific connection identifying information comprises a source address value, destination address value, source port value, and destination port value.

8. A method as recited in claim 4, wherein the standby transport protocol process notifies a logically higher application that the transport protocol connection is available only after receiving the one or more messages and an end message that signals an end of the one or more messages.

9. A method as recited in claim 4, wherein the active transport protocol process notifies a logically higher application that the transport protocol connection is available only after receiving a completion message from the standby transport protocol process.

10. A method as recited in claim 4 wherein the one or more messages comprise any of egress properties, ingress properties, rate properties, statistics, or options associated with the transport protocol connection.

11. A method as recited in claim 4 wherein the active transport protocol process receives a request for state verification, the active transport protocol process sends a request for statistics to the standby transport protocol process, the standby transport protocol process retrieves one or more statistics values, the standby transport protocol process sends a responsive statistics message comprising the one or more statistics values to the active transport protocol process, and the transport protocol process sends a reply message comprising the statistics values to a logically higher application.

12. A network routing apparatus, comprising:

an active route processor;

a standby route processor that is coupled to the active route processor in a redundant arrangement;

a computer-readable medium that is accessible to the active route processor and the standby route processor, and comprising one or more sequences of instructions which, when executed by the route processors, cause the route processors to perform the steps of;

receiving, at an active transport protocol process coupled to a standby transport protocol process, information identifying a newly created transport layer connection maintained at the active transport protocol process;

assigning a unique connection identifier to the transport layer connection;

sending the unique connection identifier, in association with other, protocol-specific connection identifying information, to the standby protocol process;

sending, to the standby transport protocol process, one or more messages comprising one or more properties or statistics associated with the transport layer connection, wherein the messages identify the transport layer connection using the unique connection identifier.

13. An apparatus as recited in claim 12, wherein the messages conform to a specified transport protocol synchronization message format and are not TCP segments.

14. An apparatus as recited in claim 12, wherein both the active transport protocol process and the standby transport protocol process implement TCP.

15. An apparatus as recited in claim 12, wherein the protocol-specific connection identifying information comprises a source address value, destination address value, source port value, and destination port value.

16. An apparatus as recited in claim 12, wherein the standby transport protocol process notifies a logically higher application that the transport protocol connection is available only after receiving the one or more messages and an end message that signals an end of the one or more messages.

17. An apparatus as recited in claim 12, wherein the active transport protocol process notifies a logically higher application that the transport protocol connection is available only after receiving a completion message from the standby transport protocol process.

18. An apparatus as recited in claim 12 wherein the one or more messages comprise any of egress properties, ingress properties, rate properties, statistics, or options associated with the transport protocol connection.

19. An apparatus as recited in claim 12 wherein the active transport protocol process receives a request for state verification, the active transport protocol process sends a request for statistics to the standby transport protocol process, the standby transport protocol process retrieves one or more statistics values, the standby transport protocol process sends a responsive statistics message comprising the one or more statistics values to the active transport protocol process, and the transport protocol process sends a reply message comprising the statistics values to a logically higher application.

20. A network routing apparatus, comprising:

means for receiving, at a network element comprising an active transport protocol process coupled to a standby transport protocol process, information identifying a newly created transport layer connection maintained at the active transport protocol process;

means for assigning a unique connection identifier to the transport layer connection;

means for sending the unique connection identifier, in association with other, protocol-specific connection identifying information, to the standby protocol process;

means for sending, to the standby transport protocol process, one or more messages comprising one or more properties or statistics associated with the transport layer connection, wherein the messages identify the transport layer connection using the unique connection identifier.

21. An apparatus as recited in claim 20, wherein the messages conform to a specified transport protocol synchronization message format and are not TCP segments.

22. An apparatus as recited in claim 20, wherein both the active transport protocol process and the standby transport protocol process implement TCP.

23. An apparatus as recited in claim 20, wherein the protocol-specific connection identifying information comprises a source address value, destination address value, source port value, and destination port value.

24. An apparatus as recited in claim 20, wherein the standby transport protocol process notifies a logically higher application that the transport protocol connection is available only after receiving the one or more messages and an end message that signals an end of the one or more messages.

25. An apparatus as recited in claim 20, wherein the active transport protocol process notifies a logically higher application that the transport protocol connection is available only after receiving a completion message from the standby transport protocol process.

26. An apparatus as recited in claim 20 wherein the one or more messages comprise any of egress properties, ingress properties, rate properties, statistics, or options associated with the transport protocol connection.

27. An apparatus as recited in claim 20 wherein the active transport protocol process receives a request for state verification, the active transport protocol process sends a request for statistics to the standby transport protocol process, the standby transport protocol process retrieves one or more statistics values, the standby transport protocol process sends a responsive statistics message comprising the one or more statistics values to the active transport protocol process, and the transport protocol process sends a reply message comprising the statistics values to a logically higher application.

28. A computer-readable medium carrying one or more sequences of instructions for upgrading network protocol software, which instructions, when executed by one or more processors, cause the one or more processors to carry out the steps of:

receiving, at a network element comprising an active transport protocol process coupled to a standby transport protocol process, information identifying a newly created transport layer connection maintained at the active transport protocol process;

assigning a unique connection identifier to the transport layer connection;

sending the unique connection identifier, in association with other, protocol-specific connection identifying information, to the standby protocol process;

sending, to the standby transport protocol process, one or more messages comprising one or more properties or statistics associated with the transport layer connection, wherein the messages identify the transport layer connection using the unique connection identifier.