Method to provide high availability in network elements using distributed architectures

• US 20060072480A1
• Filed: 09/29/2004
• Published: 04/06/2006
• Est. Priority Date: 09/29/2004
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Khosravi, Hormuzd, Bakshi, Sanjay, Balakrishnan, Santosh, Deval, Manasi, Ahmed, Suhail
• Granted Patent: US 7,453,797 B2
• Time in Patent Office: Days
• US Class Current: 370/254
• CPC Class Codes: H04L 1/22 using redundant apparatus to increase reliability
• CPC Class Codes: H04L 45/60 Router architectures

Abstract

A method to provide high availability in network elements using distributed architectures. The method employs multiple software components that are distributed across data/forwarding plane and control plane elements in a network element. The software components in the data/forwarding plane include active and standby components. Components in the control plane are provided to communicate with the components in the data/forwarding plane. A keep-alive messaging mechanism is used to monitor operation of the various elements in the network element. Upon detection of a failure to a hardware or software component, the data/forwarding plane and/or control plane elements are reconfigured, as applicable, to replace a failed active component with a corresponding standby component. This enables the network element to be reconfigured in a manner that is transparent to other network elements, and provided high availability for the network element.

Claims

1. A method comprising:

configuring a network element to include multiple sets of redundant data/forwarding plane components, each set including an active component and a standby component;

monitoring for a failure of an active data/forwarding plane component in the network element; and

automatically reconfiguring the network element to employ a corresponding standby data/forwarding plane component in place of the active data/forwarding plane component that has failed.

2. The method of claim 1, wherein the active component that fails is a data/forwarding plane line card.

3. The method of claim 1, wherein the active component that fails is a software component running on a data/forwarding plane line card.

4. The method of claim 3, wherein the software component comprises a worker control plane protocol module (CPPM) that is employed in connection with a corresponding controller CPPM operating on a control card in the network element to perform a routing or switching protocol operation.

5. The method of claim 3, wherein the worker CPPM and the controller CPPM perform operations in accordance with the Open Shortest Path First (OSPF) routing protocol.

6. The method of claim 3, wherein the worker CPPM and the controller CPPM perform operations in accordance with the Border Gateway Protocol (BGP) routing protocol.

7. The method of claim 1, wherein failure of the data/forwarding plane component is detected using a keep-alive messaging mechanism that employs an exchange of keep-alive and callback messages between software components running on different data/forwarding plane and/or control plane elements.

8. The method of claim 1, wherein the operations correspond to a fast fail-over in the data/forwarding plane of a network element, and the fast fail-over is performed in a manner that is transparent to a routing protocol being implemented by a control plane element in the network element.

9. The method of claim 1, wherein the multiple sets of data/forwarding plane components include sets of redundant software components, the method further including:

assigning one component in the set of redundant software components as an active component;

assigning at least one component in the set of redundant software components as a standby component; and

periodically synchronizing state information for the active and standby components.

10. A method comprising:

configuring a network element to include multiple sets of redundant control plane components, each redundant set including an active component and a standby component;

monitoring for a failure of an active control plane component; and

automatically reconfiguring the network element to employ a corresponding standby control plane component in place of the active control plane component that has failed.

11. The method of claim 10, wherein the active component that fails is a control plane card.

12. The method of claim 10, wherein the active component that fails is a software component running on a control plane card.

13. The method of claim 12, wherein the software component comprises a control plane protocol module (CPPM) that is employed in the control plane to perform a routing or switching protocol operation.

14. The method of claim 13, further comprising:

employing the CPPM in the control plane as a controller CPPM in conjunction with a worker CPPM implemented on a data plane element to facilitate operation of the routing or switching protocol;

maintaining state change information that occurs while the controller CPPM is unavailable; and

providing the state change information that occurred while the controller CPPM was unavailable to the controller CPPM or a replacement controller CPPM when the controller CPPM returns to operation or an original control plane element hosting the controller CPPM is replaced by a replacement control plane element hosting the replacement controller CPPM.

15. The method of claim 14, wherein the controller CPPM and worker controller CPPM perform operations in accordance with at least one of the Open Shortest Path First (OSPF) and Border Gateway Protocol (BGP) routing protocols.

16. The method of claim 10, wherein the method performs a fast fail-over process in the control plane that is performed in a manner that is transparent to other network elements to which the network element is coupled in a network.

17. The method of claim 10, wherein failure of the control plane component is detected using a keep-alive messaging mechanism that employs an exchange of keep-alive and callback messages between software components running on one of:

a) separate control plane cards;

b) a common control plane cards; and

c) a control plane card hosting the software component that has failed and a data/forwarding plane card in the network element.

18. A machine-readable medium, to store software modules to execute on data/forwarding plane and control plane elements in a network element, which, if executed perform operations including:

monitoring for a failure of an active data/forwarding plane component in the network element; and

automatically reconfiguring the network element to employ a corresponding standby data/forwarding plane component in place of the active data/forwarding plane component that has failed.

19. The machine-readable medium of claim 18, wherein the active component that fails is a data/forwarding plane line card.

20. The machine-readable medium of claim 18, wherein the active component that fails comprises one of the software modules.

21. The machine-readable medium of claim 18, wherein the software modules include a worker control plane protocol module (CPPM) to execute on a data/forwarding plane line card that is employed in connection with a corresponding controller CPPM to execute on a control card in the network element to perform a routing or switching protocol operation.

22. A machine-readable medium, to store software modules to execute in a network element, which, if executed perform operations including:

monitoring for a failure of an active control plane component in the network element; and

automatically reconfiguring the network element to employ a corresponding standby control plane component in place of the active control plane component that has failed.

23. The machine-readable medium of claim 22, wherein the active control plane component that fails is a control plane line card.

24. The machine-readable medium of claim 22, wherein the active component that fails comprises one of the software modules.

25. The machine-readable medium of claim 22, wherein failure of the control plane component is detected using a keep-alive messaging mechanism that employs an exchange of keep-alive and callback messages between software components running on one of:

a) separate control plane cards;

b) a common control plane cards; and

c) a control plane card hosting the software component that has failed and a data/forwarding plane card in the network element.

26. The machine-readable medium of claim 22, wherein software modules includes a controller control plane protocol module (CPPM) and a worker CPPM, the controller CPPM to execute on a control plane element as a controller CPPM in conjunction with a worker CPPM to execute on a data plane element to facilitate operation of a routing or switching protocol, and wherein execution of the software modules performs further operations including;

synchronizing state information between the controller CPPM and the worker CPPM;

maintaining state change information that occurs while the controller CPPM is unavailable; and

providing the state change information that occurred while the controller CPPM was unavailable to the controller CPPM or a replacement controller CPPM when the controller CPPM returns to operation or an original control plane element hosting the controller CPPM is replaced by a replacement control plane element hosting the replacement controller CPPM.

27. A network element comprising:

an interconnect;

a first control card, coupled to the interconnect;

first and second data/forwarding plane line cards;

coupled to the interconnect; and

a plurality of software components stored on the first control card and the first and second data/forwarding plane line cards, wherein execution of the software components by the control card and first and second data/forwarding plane line cards performs operations including;

monitoring for a failure of an active data/forwarding plane component in the network element; and

automatically reconfiguring the network element to employ a corresponding standby data/forwarding plane component in place of the active data/forwarding plane component that has failed.

28. The network element of claim 27, wherein execution of the software components detects a failure of the first data/forwarding plane line card and automatically reconfigures the network element to employ the second data/forwarding plane line card to take over data/forwarding plane operations that were previously handled by the first data/forwarding plane line card.

29. The network element of claim 27, wherein execution of the software components perform further operations, including:

monitoring for a failure of an active control plane component in the network element; and

automatically reconfiguring the network element to employ a corresponding standby control plane component in place of the active control plane component that has failed

30. The network element of claim 29, further comprising a second control card, coupled to the interconnect and having a plurality of software components stored thereon, and execution of the software components perform further operations, including:

detecting a failure of the first control card; and

, in response thereto,

automatically reconfiguring the network element to employ the second control card to take over control plane operations that were previously handled by the first control card.