Method and system for providing robust connections in networking applications

• US 7,289,433 B1
• Filed: 12/29/2000
• Issued: 10/30/2007
• Est. Priority Date: 10/24/2000
• Status: Active Grant

• Current Assignee: Ciena Corporation
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Chmara, Thomas P., Sanchez, Pedro I., Doray, Bernard J.
• Primary Examiner(s): NGUYEN, BRIAN D
• Application Number:
  US09/750,096
• Time in Patent Office: 2,496 Days
• Field of Search: 370216-228, 370/229, 370/503, 370/509, 714/13, 714/6, 379/9.05, 709/225
• US Class Current: 370/219
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 45/586 of virtual routers

Abstract

A method for preventing information losses due to network node failure is disclosed. The method comprises the steps of operatively connecting at least one backup node to a primary node, followed by synchronizing the at least one backup node and the primary node. Next, the method comprises receiving, from a first endpoint, ingress traffic in the primary node and replicating the ingress traffic to the at least one backup node. Next, the method outputs, from the primary mode, primary egress traffic and outputs, from the at least one backup node, backup egress traffic. The method then determines if the primary node has failed. Then, the method transmits, to a second endpoint, the primary egress traffic if it is determined that the primary node has not failed, and transmits, to the second endpoint, the backup egress traffic from a selected one of the at least one backup nodes if it is determined that the primary node has failed.

Claims

1. A method for preventing information losses due to network node failure, the method comprising the steps of:

operatively connecting at least one backup node to a primary node;

synchronizing the at least one backup node and the primary node;

receiving, from a first endpoint, ingress traffic in the primary node;

replicating the ingress traffic to the at least one backup node;

outputting, from the primary node, primary egress traffic;

outputting, from the at least one backup node, backup egress traffic;

determining if the primary node has failed;

transmitting, to a second endpoint, the primary egress traffic if it is determined that the primary node has not failed; and

transmitting, to the second endpoint, the backup egress traffic from a selected one of the at least one backup nodes if it is determined that the primary node has failed,

wherein the backup egress traffic from the selected one of the at least one backup nodes replaces the primary egress traffic to the second endpoint and the backup node becomes the primary node for subsequent traffic.

2. The method of claim 1, wherein the primary node and the at least one backup node are network routers.

3. The method of claim 1, wherein the primary node and the at least one backup node are security engines for receiving encrypted ingress traffic and outputting decrypted egress traffic.

4. The method of claim 1, wherein the step of synchronizing the at least one backup node and the primary node further comprises the steps of:

transmitting synchronization information from the primary node to the at least one backup node.

5. The method of claim 4, wherein the step of transmitting synchronization information from the primary node to the at least one backup node further comprises the steps of:

transmitting at least one checkpoint message from the primary node to the at least one backup node, wherein the at least one checkpoint message includes static information relating to the primary node as well as any outstanding session context for the primary node.

6. The method of claim 5, further comprising the steps of:

receiving, from the at least one backup node, a checkpoint message acknowledgment for each of said at least one checkpoint messages;

determining whether each of the checkpoint message acknowledgments was received prior to a change in flow state;

transmitting a synchronization declaration from the primary node to the at least one backup node if it is determined that each of the checkpoint message acknowledgments was received prior to a change in flow state; and

transmitting at least one new checkpoint message from the primary node to the backup node if it is determined that each of the checkpoint packet acknowledgments was not received prior to a change in flow state.

7. The method of claim 4, further comprising the steps of:

periodically assessing synchronization maintenance between the primary node and the at least one backup node.

8. The method of claim 7, wherein the step of periodically assessing synchronization maintenance further comprises the step of:

transmitting at least a portion of internal state information from the primary node to the at least one backup node sufficient to permit replication of primary node traffic on the at least one backup node.

9. The method of claim 1 wherein the step of replicating the ingress traffic to the at least one backup node comprises simultaneously passing a copy of the ingress traffic to the at least one backup node.

10. The method of claim 1 wherein the ingress and egress traffic comprise session context information.

11. An apparatus for preventing information losses due to network node failure, the apparatus comprising:

a primary node;

at least one backup node operatively connected to the primary node;

synchronizing means operatively connected to the primary node and the backup node for synchronizing the at least one backup node and the primary node;

means for receiving ingress traffic in the primary node from a first endpoint;

means for replicating the ingress traffic to the at least one backup node;

means for outputting primary egress traffic from the primary node;

means for outputting backup egress traffic from the at least one backup node;

determining means operatively connected to the primary node and the at least one backup node for determining whether the primary node has failed;

means for transmitting the primary egress traffic from the primary node to a second endpoint if the determining means determine that the primary node has not failed; and

means for transmitting the backup egress traffic from a selected one of the at least one backup nodes to the second endpoint if the determining means determine that the primary node has failed.

12. The apparatus of claim 11, wherein the primary node and the at least one backup node are network routers.

13. The apparatus of claim 11, wherein the primary node and the at least one backup node are security engines for receiving encrypted ingress traffic and outputting decrypted egress traffic.

14. The apparatus of claim 11, wherein the synchronizing means further comprise:

means for transmitting synchronization information from the primary node to the at least one backup node.

15. The apparatus of claim 14, wherein the means for transmitting synchronization information further comprise:

means for transmitting at least one checkpoint message from the primary node to the at least one backup node, wherein the at least one checkpoint message includes static information relating to the primary node as well as any outstanding session context for the primary node.

16. The apparatus of claim 15, further comprising:

means for receiving in the primary node, from the at least one backup node, a checkpoint message acknowledgment for each of said at least one checkpoint message;

second determining means for determining whether each of the checkpoint message acknowledgments was received prior to a change in flow state;

means for transmitting a synchronization declaration from the primary node to the at least one backup node if it is determined that each of the checkpoint message acknowledgments was received prior to a change in flow state; and

means for transmitting at least one new checkpoint message from the primary node to the backup node if it is determined that each of the checkpoint message acknowledgments was not received prior to a change in flow state.

17. The apparatus of claim 14, further comprising:

means for periodically assessing synchronization maintenance between the primary node and the at least one backup node.

18. The apparatus of claim 17, wherein the means for periodically assessing synchronization maintenance further comprise:

means for transmitting at least a portion of an internal state of the primary node to the backup node sufficient to permit replication of primary node traffic on the at least one backup node.

19. The apparatus of claim 11 wherein the means for replicating the ingress traffic to the at least one backup node comprises means for simultaneously passing a copy of the ingress traffic to the at least one backup node.

20. The apparatus of claim 11 wherein the ingress and egress traffic comprise session context information.