BFD rate-limiting and automatic session activation

• US 20100149969A1
• Filed: 01/28/2009
• Published: 06/17/2010
• Est. Priority Date: 03/18/2005
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Rahman, Reshad, Simard, Jean-Marc, Hopps, Christian E., Ward, David, Toscano, David
• Granted Patent: US 7,903,548 B2
• Time in Patent Office: Days
• US Class Current: 370/229
• CPC Class Codes: H04L 43/50 Testing arrangements

Abstract

A system and method for bidirectional forwarding detection (BFD) rate-limiting and automatic BFD session activation includes tracking a total bidirectional forwarding detection (BFD) packet rate for a line card (LC) of the node, and rejecting operations associated with creation of a new BFD session that would cause the total BFD packet rate to exceed a predetermined maximum rate. The new BFD session is stored in a state on the node and the operations of the new BFD session are automatically retried at a time when doing so would not exceed the predetermined maximum rate. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).

Claims

1-12. -12. (canceled)

13. A computer-readable memory encoded with a computer program for a network node operable to:

track a total bidirectional forwarding detection (BFD) packet rate for a line card (LC) of the network node;

reject operations associated with creation of a new BFD session that would cause the total BFD packet rate to exceed a predetermined maximum rate, the new BFD session being stored in a state on the network node; and

retry the operations of the new BFD session at a time when packet-per-second (pps) resources become available such that the operations would not exceed the predetermined maximum rate.

14. The computer-readable memory of claim 13 further operable to:

reject a request to modify parameters of an existing BFD session when doing so would cause the total BFD packet rate to exceed the predetermined maximum rate.

15. The computer-readable memory of claim 14 further operable to:

store the request; and

modify the parameters of the existing BFD session in accordance with the request when doing so would not exceed the predetermined maximum rate.

16. The computer-readable memory of claim 13 wherein the predetermined maximum rate is implemented in a device on the LC of the network node.

17. A method comprising:

negotiating parameters associated with creation of a bidirectional forwarding detection (BFD) session on a network node, the parameters including a packet per second (pps) rate;

rejecting operations associated with the BFD session that would cause a total BFD pps rate for a line card (LC) of the network node to exceed a predetermined maximum pps rate of a hardware policer device of the node;

maintaining the BFD session in a de-activated state on the node;

automatically activating the BFD session when doing so would not exceed the predetermined maximum pps rate.

18. The method of claim 17 further comprising:

rejecting a request to modify parameters of an existing BFD session that would cause the total BFD pps rate to exceed the predetermined maximum pps rate.

19. The method of claim 18 further comprising:

storing the request on the node; and

automatically modifying the parameters of the existing BFD session in accordance with the request when doing so would not exceed the predetermined maximum pps rate.

20. A network node comprising:

a processor; and

a device configured to deliver bidirectional forwarding detection (BFD) packets to the processor when an incoming rate or the BFD packets is less than a predetermined maximum rate;

the processor being configured to reject operations associated with a new BFD session that would cause a total BFD packet rate to exceed the predetermined maximum rate, the new BFD session being maintained on the node and the operations being automatically retried when doing so would not exceed the predetermined maximum packet rate.

21. The network node of claim 20 wherein the processor and the device are associated with a line card of the node.

22. The network node of claim 20 wherein the processor is further configured to reject a request to modify parameters of an existing BFD session when doing so would cause the total BFD packet rate to exceed the predetermined maximum rate.

23. The network node of claim 22 wherein the processor is further configured to automatically modify the parameters of the existing BFD session in accordance with the request when doing so would not exceed the predetermined maximum rate.

24. A computer-readable memory encoded with a computer program for a network node operable to:

track a total bidirectional forwarding detection (BFD) packet rate for a line card (LC) of the network node;

temporarily reject any BFD session operations that would cause the total BFD packet rate to exceed a predetermined rate limit of a policer device associated with the network node, the temporarily rejected BFD session operations being stored on the network node; and

automatically retry the BFD session operations stored on the network node at when doing so would not exceed the predetermined rate limit.