System, device, and method for sending keep-alive messages in a communication network

1. A method for sending keep-alive messages by a node to a neighbor in a communication network, the method comprising:

measuring a reliability of a communication link to the neighbor; and

periodically calculating a reliability factor for communicating with the neighbor based upon the reliability of the communication link to the neighbor;

varying a frequency for sending keep-alive messages to the neighbor based upon the reliability factor; and

sending keep-alive messages by the node to the neighbor in accordance with those steps.

2. The method of claim 1 , wherein periodically calculating a reliability factor for communicating with the neighbor comprises:

determining a reliability for the neighbor; and

wherein the step of calculating the reliability factor is further based upon the reliability for the neighbor.

3. The method of claim 1 , wherein varying a frequency for sending keep-alive messages to the neighbor based upon the reliability factor comprises:

setting the frequency for sending keep-alive messages to the neighbor in inverse proportion to the reliability factor.

4. The method of claim 1 , further comprising:

updating the reliability factor; and

adjusting the frequency for sending keep-alive messages to the neighbor based upon the reliability factor.

5. The method of claim 2 , wherein periodically calculating a reliability factor for communicating with the neighbor comprises:

assigning a relative weight to each of the reliability for the neighbor and the reliability of the communication link to the neighbor;

calculating the reliability factor to be a weighted average of the reliability for the neighbor and the reliability of the communication link to the neighbor.

6. The method of claim 4 , wherein adjusting the frequency for sending keep-alive messages to the neighbor comprises:

reducing the frequency for sending keep-alive messages to the neighbor, if the updated reliability factor represents a reliability improvement for communicating with the neighbor; and increasing the frequency for sending keep-alive messages to the neighbor, if the updated reliability factor represents a reliability degradation for communicating with the neighbor.

7. The method of claim 5 , wherein the reliability factor (RF) is calculated using the below equation, where A is the measured reliability of the communication link to the neighbor, B is the determined reliability of the neighbor, W 1 is a relative weight for A and W 2 is a relative weight for B:

RF =( W 1* A+W 2* B )

8. A device for sending keep-alive message to a neighbor in a communication network, the device comprising:

a processor, a memory and a transmitter;

the processor executing a computer program stored in the memory, the computer program including:

reliability calculation logic operably coupled to determine a reliability for a communication link to the neighbor and periodically calculate a reliability factor for communicating with the neighbor based upon the reliability for the communication link to the neighbor; and

frequency variation logic responsive to the reliability calculation logic and operably coupled to calculate a frequency for sending keep-alive messages to the neighbor via the transmitter based upon the reliability factor.

9. The device of claim 8 , wherein the reliability calculation logic is operably coupled to determine a reliability for the neighbor and to calculate the reliability factor based also upon the reliability for the neighbor.

10. The device of claim 8 , wherein the reliability calculation logic is operably coupled to also determine a reliability for the neighbor, measure a reliability for a communication link to the neighbor, assign a relative weight to each of the reliability for the neighbor and the reliability for the communication link to the neighbor, and calculate the reliability factor to be a weighted average of the reliability of the neighbor and the reliability of the communication link to the neighbor.

11. The device of claim 8 , wherein the frequency variation logic is operably coupled to set the frequency for sending keep-alive messages to the neighbor in inverse proportion to the reliability factor.

12. The device of claim 8 , wherein the reliability calculation logic is operably coupled to update the reliability factor, and wherein the frequency variation logic is operably coupled to adjust the frequency for sending keep-alive messages to the neighbor based upon the updated reliability factor.

13. The device of claim 10 , wherein the reliability factor (RF) is calculated using the below equation, where A is the determined reliability of the communication link to the neighbor, B is the determined reliability of the neighbor, W 1 is a relative weight for A and W 2 is a relative weight for B:

RF=(W 1 *A+W 2 *B).

14. The device of claim 12 , wherein the frequency variation logic is operably coupled to reduce the frequency for sending keep alive messages to the neighbor if the updated reliability factor represents a reliability improvement for communicating with the neighbor and increase the frequency for sending keep-alive messages to the neighbor if the updated reliability factor represents a degradation for communicating with the neighbor.

15. A program product recorded on a computer readable device sending keep-alive messages to a neighbor in a communication network, the program product comprising:

reliability calculation logic operably coupled to measure a reliability for a communication link to the neighbor and to periodically calculate a reliability factor for communicating with the neighbor based upon the reliability for the communication link to the neighbor; and

frequency variation logic responsive to the reliability calculation logic and operably coupled to determine a frequency for sending keep-alive messages to the neighbor based upon the reliability factor.

16. The program product of claim 15 , wherein the reliability calculation logic is programmed to determine a reliability for the neighbor and calculate the reliability factor based upon the reliability for the neighbor.

17. The program product of claim 15 , wherein the reliability calculation logic is operably coupled to also determine a reliability for the neighbor, measure a reliability for a communication link to the neighbor, assign a relative weight to each of the reliability for the neighbor and the reliability for the communication link to the neighbor, and calculate the reliability factor to be a weighted average of the reliability of the neighbor and the reliability of the communication link to the neighbor.

18. The program product of claim 15 , wherein the frequency variation logic is programmed to set the frequency for sending keep-alive messages to the neighbor in inverse proportion to the reliability factor.

19. The program product of claim 15 , wherein the reliability calculation logic is programmed to update the reliability factor, and wherein the frequency variation logic is operably coupled to adjust the frequency for sending keep-alive messages to the neighbor based upon the updated reliability factor.

20. The program product of claim 19 , wherein the frequency variation logic is programmed to reduce the frequency for sending keep alive messages to the neighbor if the updated reliability factor represents a reliability improvement for communicating with the neighbor and increase the frequency for sending keep-alive messages to the neighbor if the updated reliability factor represents a degradation for communicating with the neighbor.

21. Apparatus comprising:

a plurality of interconnected devices including a node and a neighbor in communication over a link,

wherein the node is operably coupled to send keep-alive messages to the neighbor, and

wherein the node is operably coupled to vary a frequency for sending keep-alive messages to the neighbor based upon a periodically computed reliability factor for communicating with the neighbor over the communication link,

wherein the node is operably coupled to calculate the reliability factor based upon a reliability for the neighbor and a measured reliability for the communication link.

22. The apparatus of claim 21 , wherein the node is operably coupled to set the frequency for sending keep-alive messages to the neighbor in inverse proportion to the reliability factor.