High availability ethernet backplane architecture

• US 20040085893A1
• Filed: 10/31/2002
• Published: 05/06/2004
• Est. Priority Date: 10/31/2002
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Conexant Systems Incorporated (Synaptics Incorporated)
• Inventors: Chang, Rong-Feng, Wang, Linghsiao, Lin, Eric, Yik, James Ching-Shau
• Granted Patent: US 7,835,265 B2
• Time in Patent Office: Days
• US Class Current: 370/216
• CPC Class Codes: H04L 41/0663 Performing the actions predefined by failover planning, e.g. switching to standby network elements
• CPC Class Codes: H04L 41/0677 Localisation of faults
• CPC Class Codes: H04L 43/0811 by checking connectivity
• CPC Class Codes: H04L 43/10 Active monitoring, e.g. heartbeat, ping or trace-route
• CPC Class Codes: H04L 43/103 with adaptive polling, i.e. dynamically adapting the polling rate
• CPC Class Codes: H04L 49/1523 Parallel switch fabric planes
• CPC Class Codes: H04L 49/351 for local area network [LAN], e.g. Ethernet switches
• 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

A high availability backplane architecture. The backplane system includes redundant node boards operatively communicating with redundant switch fabric boards. Uplink ports of the node boards are logically grouped into trunk ports at one end of the communication link with the switch fabric boards. The node boards and the switch fabric boards routinely perform link integrity checks when operating in a normal mode such that each can independently initiate failover to working ports when a link failure is detected. Link failure is detected either by sending a link heartbeat message after the link has had no traffic for a predetermined interval, or after receiving a predetermined consecutive number of invalid packets. Once the link failure is resolved, operation resumes in normal mode.

Claims

1. A method for determining failure of a communications link, the steps comprising:

setting a timer for a predetermined interval;

waiting the predetermined interval for a link heartbeat packet;

resetting the timer to the predetermined interval whenever a valid packet is received; and

changing the status of the communication link to a failure mode when the timer expires.

2. The method of claim 1, the steps further comprising changing the status of the communication link to failure mode after a predetermined number of consecutive invalid packets are received.

3. A method for a node board to handle network failure, the steps comprising:

creating a trunk port of redundant ports;

performing a link integrity check on each of the redundant ports;

updating a media access control table when a port failure is detected; and

mapping traffic for a failed port to a working port.

4. The method of claim 3 further comprising:

updating the media access control table when a valid packet is received by the failed port.

5. The method of claim 3, the performing step comprising:

setting a timer for a predetermined interval;

waiting the predetermined interval for a link heartbeat packet;

resetting the timer to the predetermined interval whenever a valid packet is received; and

changing the status of the communication link to a failure mode when the timer expires.

6. The method of claim 5, the performing step further comprising changing the status of the communication link to failure mode after a predetermined number of consecutive invalid packets are received.

7. A method for a switch fabric board having a redirect table to handle a link failure, the steps comprising:

performing a link integrity check for each link coupled to the switch fabric board; and

enabling a link failover mode upon failure of a link integrity check, the steps of the link failover mode comprising

sending link failure data to at least one other switch fabric board,

updating a media access control table with link failure data, and

mapping a failed port to a redirect port.

8. The method of claim 7, the performing step comprising:

setting a timer for a predetermined interval;

waiting the predetermined interval for a link heartbeat packet;

resetting the timer to the predetermined interval whenever a valid packet is received; and

changing the status of the communication link to a failure mode when the timer expires.

9. The method of claim 8, the performing step further comprising changing the status of the communication link to failure mode after a predetermined number of consecutive invalid packets are received.

10. A method for sending a link heartbeat message, the steps comprising:

setting a timer; and

sending a link heartbeat packet when the timer expires.

11. The method of claim 10 further comprising

receiving a packet for sending;

sending the packet; and

resetting the timer whenever a packet is sent.

12. A media access control packet, comprising:

a destination media access control address;

a source media access control address;

an ethertype field indicating a media access control format; and

an opcode

wherein the ethertpe value in hexadecimal is 88-08.

13. The media access control packet of claim 12 wherein the opcode is an equivalent predetermined two byte value for a sender and a receiver.

14. The media access control packet of claim 13 further comprising padding bytes sufficient to make the packet 64 bytes in length.

15. A backplane system comprising:

a plurality of node boards;

a plurality of switch fabric boards, each switch fabric board having a redirect table;

wherein each node of the plurality of node boards has a single link to each of the plurality of switch fabric boards

wherein when a switch fabric board detects a failed link, the switch fabric board communicates failed link data to the remaining switch fabric boards, causing the other switch fabric boards to update their redirect tables.

16. The system of claim 15 wherein the failed link is detected by failing to receive a media access control layer link heartbeat message packets after a predetermined time interval has elapsed after a last packet was received.

17. The system of claim 15 wherein the failed link is detected after a predetermined number of consecutive invalid packets are received.

18. A computer-readable medium of instructions, comprising:

means for setting a timer for a predetermined interval;

means for waiting the predetermined interval for a link heartbeat packet;

means for resetting the timer to the predetermined interval whenever a valid packet is received; and

means for changing the status of the communication link to a failure mode when the timer expires.

19. The computer-readable medium of instructions of claim 18, further comprising means for changing the status of the communication link to failure mode after a predetermined number of consecutive invalid packets are received.

20. The computer-readable medium of instructions, comprising:

means for creating a trunk port of redundant ports;

means for performing a link integrity check on each of the redundant ports;

means for updating a media access control table when a port failure is detected; and

means for mapping traffic for a failed port to a working port.

21. The computer-readable medium of instructions of claim 20 further comprising:

means for updating the media access control table when a valid packet is received by the failed port.

22. The computer-readable medium of instructions of claim 20, the means for performing further comprising:

means for setting a timer for a predetermined interval;

means for waiting the predetermined interval for a link heartbeat packet;

means for resetting the timer to the predetermined interval whenever a valid packet is received; and

means for changing the status of the communication link to a failure mode when the timer expires.

23. The computer-readable medium of instructions of claim 22, the means for performing further comprising means for changing the status of the communication link to failure mode after a predetermined number of consecutive invalid packets are received.

24. A computer-readable medium of instructions, comprising:

means for performing a link integrity check for each link coupled to the switch fabric board; and

means for enabling a link failover mode upon failure of a link integrity check, the steps of the link failover mode comprising

means for sending link failure data to at least one other switch fabric board,

means for updating a media access control table with link failure data, and

means for mapping a failed port to a redirect port.

25. The computer-readable medium of instructions of claim 24, the means for performing further comprising:

means for setting a timer for a predetermined interval;

means for waiting the predetermined interval for a link heartbeat packet;

means for resetting the timer to the predetermined interval whenever a valid packet is received; and

means for changing the status of the communication link to a failure mode when the timer expires.

26. The computer-readable medium of instructions of claim 25, the means for performing further comprising means for changing the status of the communication link to failure mode after a predetermined number of consecutive invalid packets are received.