Techniques for processing incoming failure detection protocol packets

• US 20090279440A1
• Filed: 12/10/2007
• Published: 11/12/2009
• Est. Priority Date: 01/11/2007
• Status: Active Grant

• Current Assignee: Extreme Networks, Inc.
• Original Assignee: Foundry Networks Incorporated (Broadcom, Inc.)
• Inventors: Wong, Yuen, Moobed, Pedman
• Granted Patent: US 8,395,996 B2
• Time in Patent Office: Days
• US Class Current: 370/242
• CPC Class Codes: H04L 41/0631 using root cause analysis; using analysis of correlation between notifications, alarms or events based on decision criteria, e.g. hierarchy, tree or time analysis
• CPC Class Codes: H04L 43/0823 Errors, e.g. transmission errors

Abstract

Techniques that assist in processing of failure detection protocol (FDP) packets. Techniques are provided that assist a CPU of a network device in processing incoming FDP packets. In one embodiment, only a subset of FDP packets received by the network device is forwarded to the CPU for processing, the other FDP packets are dropped and not forwarded to the CPU. In this manner, the amount of processing that a CPU of the network device has to perform for incoming FDP packets is reduced. This enables the network device to support newer FDPs with shorter periodic interval requirements.

Claims

1. A method of processing failure detection protocol packets transmitted according to a failure detection protocol and received by a network device, the method comprising:

receiving a set of packets prior to the set of packets being forwarded to a processor of the network device, the processor configured to execute software for processing failure detection protocol packets;

identifying a set of failure detection protocol packets from the set of packets;

for each packet in the set of failure detection protocol packets, determining if the failure detection protocol packet is to be forwarded to the processor; and

based upon the determining, for at least one failure detection protocol packet from the set of failure detection protocol packets, dropping the at least one failure detection protocol packet such that the at least one failure detection protocol packet is not forwarded to the processor.

2. The method of claim 1 wherein determining if the failure detection protocol packet is to be forwarded to the processor comprises:

comparing a portion of the failure detection protocol packet with reference information; and

determining that the failure detection protocol packet is not to be forwarded to the processor if the portion of the failure detection protocol packet matches the reference information.

3. The method of claim 2 wherein:

determining if the failure detection protocol packet is to be forwarded to the processor comprises identifying a first entry from a set of entries based upon the failure detection protocol packet; and

comparing the portion of the failure detection protocol packet with reference information comprises comparing the portion of the failure detection protocol packet with reference information in the first entry.

4. The method of claim 2 wherein:

determining if the failure detection protocol packet is to be forwarded to the processor comprises;

identifying a first entry from a first set of entries based upon the failure detection protocol packet; and

identifying a second entry from a second set of entries based upon information in the first entry, each entry in the second set of entries corresponding to a session; and

comparing the portion of the failure detection protocol packet with reference information comprises comparing the portion of the failure detection protocol packet with reference information in the second entry.

5. The method of claim 4 wherein identifying a first entry from the first set of entries based upon the failure detection protocol packet comprises:

applying a hash function to a portion of the failure detection protocol packet to obtain a hash result; and

identifying the first entry from the first set of entries using the hash result.

6. The method of claim 4 further comprising, for at least one entry in the second set of entries, changing a portion of information in the at least one entry after a failure detection protocol packet corresponding to a session represented by the at least one entry has been received.

7. The method of claim 1 wherein the failure detection protocol is 802.1ag.

8. The method of claim 1 wherein the failure detection protocol is Bidirectional Forwarding (BFD) protocol.

9. The method of claim 1 wherein packets in the set of failure detection protocol packets are received by the network device at a rate faster than one failure detection protocol packet per second.

10. A system for processing failure detection protocol packets transmitted according to a failure detection protocol, the system comprising:

a processor configured to execute software for processing failure detection protocol packets; and

a failure detection protocol packet handler module;

wherein the failure detection protocol packet handler module is configured to;

receive a set of packets prior to the set of packets being forwarded to the processor;

identify a set of failure detection protocol packets from the set of packets;

for each packet in the set of failure detection protocol packets, determine if the failure detection protocol packet is to be forwarded to the processor; and

based upon the determination, for at least one failure detection protocol packet from the set of failure detection protocol packets, drop the at least one failure detection protocol packet such that the at least one failure detection protocol packet is not forwarded to the processor.

11. The system of claim 10 wherein, for each packet in the set of failure detection protocol packets, the failure detection protocol packet handler module is configured to:

compare a portion of the failure detection protocol packet with reference information; and

determine that the failure detection protocol packet is not to be forwarded to the processor if the portion of the failure detection protocol packet matches the reference information.

12. The system of claim 11 wherein for each packet in the set of failure detection protocol packets, the failure detection protocol packet handler module is configured to identify a first entry from a set of entries based upon the failure detection protocol packet, and compare the portion of the failure detection protocol packet with reference information in the first entry.

13. The system of claim 11 wherein, for each packet in the set of failure detection protocol packets, the failure detection protocol packet handler module is configured to:

identify a first entry from a first set of entries based upon the failure detection protocol packet;

identify a second entry from a second set of entries based upon information in the first entry, each entry in the second set of entries corresponding to a session; and

compare the portion of the failure detection protocol packet with reference information in the second entry.

14. The system of claim 13 wherein, for each packet in the set of failure detection protocol packets, the failure detection protocol packet handler module is configured to:

apply a hash function to a portion of the failure detection protocol packet to obtain a hash result; and

identify the first entry from the first set of entries using the hash result.

15. The system of claim 13 wherein, for at least one entry in the second set of entries, the failure detection protocol packet module is configured to change a portion of information in the at least one entry after a failure detection protocol packet corresponding to a session represented by the at least one entry has been received.

16. The system of claim 10 wherein the failure detection protocol is 802.1ag.

17. The system of claim 10 wherein the failure detection protocol is Bidirectional Forwarding (BFD) protocol.

18. The system of claim 10 wherein packets in the set of failure detection protocol packets are received by the network device at a rate faster than one failure detection protocol packet per second.

19. A network device comprising:

a processor configured to execute software for processing failure detection protocol packets received by the network device; and

a field-programmable logic device (FPLD), wherein the FPLD is configured to;

receive a set of packets prior to the set of packets being forwarded to the processor;

identify a set of failure detection protocol packets from the set of packets;

for each packet in the set of failure detection protocol packets, determine if the failure detection protocol packet is to be forwarded to the processor; and

based upon the determination, for at least one failure detection protocol packet from the set of failure detection protocol packets, drop the at least one failure detection protocol packet such that the at least one failure detection protocol packet is not forwarded to the processor.

20. The network device of claim 19 wherein, for each failure detection protocol packet in the set of failure detection protocol packets, the FPLD is configured to:

identify a failure detection protocol for the failure detection protocol packet;

identify a session for the packet;

compare a portion of the failure detection protocol packet with reference information stored for the identified failure detection protocol for the identified session; and

determine that the failure detection protocol packet is not to be forwarded to the processor if the portion of the failure detection protocol packet matches the reference information stored for the identified failure detection protocol for the identified session.