BFD rate-limiting and automatic session activation

• US 20060209685A1
• Filed: 03/18/2005
• Published: 09/21/2006
• 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 7,499,395 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.

Claims

1. A processor-implemented method of operation for a node in a network, the method comprising:

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

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 being stored in a state on the node; and

automatically retrying the operations of the new BFD session when doing so would not exceed the predetermined maximum rate.

2. The processor-implemented method of claim 1 further comprising:

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

3. The processor-implemented method of claim 2 further comprising:

storing the request; and

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

4. The processor-implemented method of claim 1 wherein the predetermined maximum rate is implemented in a hardware device on the line card of the node.

5. A processor-implemented method of operation for a node in a network, the method comprising:

negotiating parameters associated with creation of a bidirectional forwarding detection (BFD) session, 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 node to exceed a predetermined maximum pps rate of a hardware policer device of the node;

maintaining the BFD session in an ADMIN_DOWN state on the node;

automatically retrying the operations of the BFD session when doing so would not exceed the predetermined maximum pps rate.

6. The processor-implemented method of claim 5 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.

7. The processor-implemented method of claim 6 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 rate.

8. A network node comprising:

a processor; and

a policer device coupled to the processor, the policer device being configured to deliver bidirectional forwarding detection (BFD) packets to the processor as long as a predetermined maximum packet rate is not exceeded; and

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

9. The network node of claim 8 wherein the processor and the policer device are associated with a line card of the node.

10. The network node of claim 8 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 packet rate.

11. The network node of claim 10 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.

12. A network node comprising:

a processor; and

means for delivering bidirectional forwarding detection (BFD) packets to the processor as long as a predetermined maximum packet rate is not exceeded; and

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