Techniques for transmitting failure detection protocol packets

• US 20090279441A1
• Filed: 12/10/2007
• Published: 11/12/2009
• Est. Priority Date: 01/11/2007
• Status: Abandoned Application

• Current Assignee: Extreme Networks, Inc.
• Original Assignee: Foundry Networks Incorporated (Broadcom, Inc.)
• Inventors: Wong, Yuen, Moobed, Pedman
• Application Number:
  US11/953,745
• Publication Number:
  US 20090279441A1
• 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 are provided for processing of failure detection protocol (FDP) packets. Techniques are provided that assist a CPU of a network device in processing incoming FDP packets. The task of transmitting FDP packets from a network device is offloaded from the CPU of the network device and instead handled by another module of the network device. In this manner, the processing that the CPU of the network device has to perform for transmitting FDP packets for the various FDP sessions of the network device is reduced. This enables the network device to support newer FDPs with shorter periodic interval requirements.

Claims

1. A method of transmitting packets according to a failure detection protocol, the method comprising:

storing, at a network device, timer information specifying a periodic time interval for transmitting a failure detection protocol packet for a failure detection protocol; and

periodically transmitting failure detection protocol packets for the failure detection protocol at times determined based upon the periodic time interval stored for the failure detection protocol;

wherein the transmitting is performed by a module of the network device other than a processor configured to execute software for processing failure detection protocol packets.

2. The method of claim 1 wherein the transmitting comprises:

determining a time for transmitting a failure detection protocol packet for the failure detection protocol based upon the periodic time interval stored for the failure detection protocol; and

transmitting a failure detection protocol packet at the determined time.

3. The method of claim 1 wherein the timer information comprises a first timer specifying the periodic time interval for the failure detection protocol and a second timer identifying when a failure detection protocol packet was last transmitted by the network device for the failure detection protocol.

4. The method of claim 3 wherein the transmitting comprises transmitting a failure detection protocol packet when the second timer equals the first timer.

5. The method of claim 3 wherein the first timer is set by the software executed by the processor of the network device and the second timer is updated by the module.

6. The method of claim 1 wherein each failure detection protocol packet for the failure detection protocol comprises a field, and wherein the transmitting comprises:

transmitting a first failure detection protocol packet based upon the periodic time interval stored for the failure detection protocol, wherein the field of the first failure is set to a first value; and

transmitting, after transmitting the first failure detection protocol packet, a second first failure detection protocol packet based upon the periodic time interval stored for the failure detection protocol, wherein the field of the second failure detection protocol packet is set to a second value that is different from the first value.

7. The method of claim 6 further comprising:

storing a parameter for the failure detection protocol;

prior to transmitting the first failure detection protocol packet, setting the field of the first failure detection protocol packet to the first value based upon the value of the parameter;

updating the value of the parameter upon transmission of the first failure detection protocol packet; and

prior to transmitting the second failure detection protocol packet, setting the field of the second failure detection protocol packet to the second value based upon the updated value of the parameter.

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

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

10. The method of claim 1 wherein the periodic time interval is less than one second.

11. A system for transmitting packets according to a failure detection protocol, the system comprising:

a memory configured to store timer information specifying a periodic time interval for transmitting a failure detection protocol packet for a failure detection protocol;

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

a module configured to periodically transmit failure detection protocol packets for the failure detection protocol at times determined based upon the periodic time interval stored for the failure detection protocol.

12. The system of claim 11 wherein the module is configured to:

determine a time for transmitting a failure detection protocol packet for the failure detection protocol based upon the periodic time interval stored for the failure detection protocol; and

transmit a failure detection protocol packet at the determined time.

13. The system of claim 11 wherein the timer information comprises a first timer specifying the periodic time interval for the failure detection protocol and a second timer identifying when a failure detection protocol packet was last transmitted by the system for the failure detection protocol.

14. The system of claim 13 wherein the module is configured to transmit a failure detection protocol packet when the second timer equals the first timer.

15. The system of claim 13 wherein the first timer is set by the software executed by the processor of the network device and the second timer is updated by the module.

16. The system of claim 11 wherein each failure detection protocol packet for the failure detection protocol comprises a field, and wherein the module is configured to:

transmit a first failure detection protocol packet based upon the periodic time interval stored for the failure detection protocol, wherein the field of the first failure is set to a first value; and

transmit, after transmission of the first failure detection protocol packet, a second first failure detection protocol packet based upon the periodic time interval stored for the failure detection protocol, wherein the field of the second failure detection protocol packet is set to a second value that is different from the first value.

17. The system of claim 16 wherein the module is configured to:

store a parameter for the failure detection protocol;

prior to transmission of the first failure detection protocol packet, set the field of the first failure detection protocol packet to the first value based upon the value of the parameter;

update the value of the parameter upon transmission of the first failure detection protocol packet; and

prior to transmission of the second failure detection protocol packet, set the field of the second failure detection protocol packet to the second value based upon the updated value of the parameter.

18. The system of claim 11 wherein the failure detection protocol is 802.1ag.

19. The system of claim 11 wherein the failure detection protocol is Bidirectional Forwarding (BFD) protocol.

20. The system of claim 11 wherein the periodic time interval is less than one second.

21. The system of claim 11 wherein the module is a field-programmable logic device.

22. A network device comprising:

a processor configured to execute software for processing failure detection protocol packets, the processor configured to set a periodic time interval for transmitting a failure detection protocol packet for a failure detection protocol;

a module configured to periodically transmit failure detection protocol packets for the failure detection protocol at times determined based upon the periodic time interval stored for the failure detection protocol; and

one or more ports configured to transmit the failure detection protocol packets from the network device.