System and method for performing a seamless switchover from a primary packet router to a secondary packet router

• US 6,327,243 B1
• Filed: 08/03/1998
• Issued: 12/04/2001
• Est. Priority Date: 08/03/1998
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Gregorat, Sandro
• Primary Examiner(s): Ngo, Ricky
• Assistant Examiner(s): TRAN, PHUC H
• Application Number:
  US09/128,431
• Time in Patent Office: 1,219 Days
• Field of Search: 370/216, 370/217, 370/218-219, 370/220, 370/227, 370/360, 370/230, 370/235, 370/242, 370/244, 370/250, 370/389, 370/392, 370/395, 370/396, 370/412, 370/428, 370/429
• US Class Current: 370/218
• CPC Class Codes: H04L 12/462 LAN interconnection over a bridge based backbone
• CPC Class Codes: H04L 45/58 Association of routers
• CPC Class Codes: H04L 49/552 by ensuring the integrity of packets received through redundant connections
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06

Abstract

There is disclosed a redundant switch comprising a primary controller capable of routing data packets from an input interface to an output interface and a secondary controller capable of performing data packet routing tasks performed by the primary controller after a switchover. The primary controller comprises: 1) an inbound queue capable of storing data packets inbound to the redundant switch; 2) an outbound queue capable of storing data packets outbound from the redundant switch; and 3) a control processor capable of processing a first data packet stored in the inbound queue and assigning an identifier to the first data packet, wherein the control processor further assigns the identifier to a second data packet, the second data packet associated with the first data packet and stored in one of the inbound queue and the outbound queue, wherein the first data packet is removed from the inbound queue only upon completion of all processing associated with the first data packet and wherein a removal of the first data packet from the inbound queue enables the second data packet to be transferred to the secondary controller during a switchover.

Claims

1. For use in a packet switched network, a redundant switch comprising a primary controller capable of routing data packets from an input interface to an output interface of said redundant switch and a secondary controller capable of performing data packet routing tasks performed by said primary controller after a switchover event, said primary controller comprising:

an inbound queue capable of storing data packets inbound to said redundant switch;

an outbound queue capable of storing data packets outbound from said redundant switch; and

a control processor capable of processing a first data packet stored in said inbound queue and assigning an identifier to said first data packet, wherein said control processor further assigns said identifier to a second data packet, said second data packet associated with said first data packet and stored in one of said inbound queue and said outbound queue, wherein said first data packet is removed from said inbound queue only upon completion of all processing associated with said first data packet and wherein a removal of said first data packet from said inbound queue enables said second data packet to be transferred to said secondary controller during a switchover.

2. The redundant switch set forth in claim 1 wherein said input interface is switchable between said primary controller and said second controller.

3. The redundant switch set forth in claim 1 wherein said output interface is switchable between said primary controller and said second controller.

4. The redundant switch set forth in claim 1 further comprising an intersystem queue capable of transferring data packets from said primary controller to said second controller.

5. The redundant switch set forth in claim 4 wherein said control processor transfers said second data packet from said outbound queue to said intersystem queue during a failover if said control processor determines that no data packet in said inbound queue is assigned said identifier also assigned to said second data packet.

6. The redundant switch set forth in claim 1 wherein said control processor assigns said identifier to said first data packet when said control processor reads said first data packet from said inbound queue.

7. The redundant switch set forth in claim 6 wherein a reading of said first data packet by said control processor does not remove said first data packet from said inbound queue.

8. The redundant switch set forth in claim 6 wherein a plurality of data packets stored in said inbound queue and in said outbound queue may not be transferred to said secondary controller until a parent data packet from which said plurality of data packets are derived is removed from said inbound queue.

9. A packet switched network comprising:

a plurality of nodes capable of transmitting and receiving data packets; and

a plurality of packet switches for routing data packets between said plurality of nodes, at least one of said plurality of packet switches comprising a redundant switch, wherein said redundant switch comprises;

a primary controller capable of routing data packets from an input interface to an output interface of said redundant switch and a secondary controller capable of performing data packet routing tasks performed by said primary controller after a switchover event, said primary controller comprising;

an inbound queue capable of storing data packets inbound to said redundant switch;

an outbound queue capable of storing data packets outbound from said redundant switch; and

a control processor capable of processing a first data packet stored in said inbound queue and assigning an identifier to said first data packet, wherein said control processor further assigns said identifier to a second data packet, said second data packet associated with said first data packet and stored in one of said inbound queue and said outbound queue, wherein said first data packet is removed from said inbound queue only upon completion of all processing associated with said first data packet and wherein a removal of said first data packet from said inbound queue enables said second data packet to be transferred to said secondary controller during a switchover.

10. The packet switched network set forth in claim 9 wherein said input interface is switchable between said primary controller and said second controller.

11. The packet switched network set forth in claim 9 wherein said output interface is switchable between said primary controller and said second controller.

12. The packet switched network set forth in claim 9 further comprising an intersystem queue capable of transferring data packets from said primary controller to said second controller.

13. The packet switched network set forth in claim 12 wherein said control processor transfers said second data packet from said outbound queue to said intersystem queue during a failover if said control processor determines that no data packet in said inbound queue is assigned said identifier also assigned to said second data packet.

14. The packet switched network set forth in claim 9 wherein said control processor assigns said identifier to said first data packet when said control processor reads said first data packet from said inbound queue.

15. The packet switched network set forth in claim 14 wherein a reading of said first data packet by said control processor does not remove said first data packet from said inbound queue.

16. The packet switched network set forth in claim 14 wherein a plurality of data packets stored in said inbound queue and in said outbound queue may not be transferred to said secondary controller until a parent data packet from which said plurality of data packets are derived is removed from said inbound queue.

20. The method set forth in claim 15 comprising the further steps of:

during a failover, determining whether a data packet in the inbound queue is assigned the same identifier assigned to the second data packet; and

transferring the second data packet from the outbound queue to the secondary controller upon a determination that no data packet in the inbound queue is assigned the same identifier assigned to the second data packet.

17. For use a redundant packet routing switch comprising a primary controller capable of routing data packets from an input interface to an output interface of the redundant switch and a secondary controller capable of performing data packet routing tasks performed by the primary controller after a switchover, a method of processing packet data in the primary controller comprising the steps of:

storing data packets inbound to the redundant switch in an inbound queue;

storing data packets outbound from the redundant switch in an outbound queue;

assigning an identifier to a first data packet stored in inbound queue;

processing the first data packet;

assigning the identifier to a second data packet associated with the first data packet;

storing the second data packet in one of the inbound queue and the outbound queue; and

removing the first data packet from the inbound queue only upon completion of all processing associated with the first data packet, the step of removing the first data packet from the inbound queue enabling the second data packet to be transferred to the secondary controller during a switchover.

18. The method set forth in claim 17 wherein the input interface is switchable between the primary controller and the second controller.

19. The method set forth in claim 17 wherein the output interface is switchable between the primary controller and the second controller.