Adjusting controls at the physical layer to control link quality at higher layers

1. A method for controlling a performance of a communication link in a communication system, the method comprising:

mapping performance of a communication link, as characterized by metrics reported by the first protocol layer in a network device, to quality of the communication link, as characterized by metrics reported by a second protocol layer in the network device, the second protocol layer being higher than the first protocol layer in a protocol stack running on the network device;

adjusting a setting of one or more communication link controls at the first protocol layer to attain a given communication link performance at the first protocol layer that, according to the mapping between the communication link performance at the first protocol layer and the quality of the communication link at the second protocol layer, corresponds to a target quality of the communication link at the second protocol layer; and

inserting a specific type of disruption in a physical layer associated with the first protocol layer and observing an effect of the specific type of disruption on quality of the communication link of the second protocol layer.

2. The method of claim 1 , wherein adjusting the setting of one or more communication link controls at the first protocol layer occurs dynamically while the communication link is in operation.

3. The method of claim 1 , wherein the adjusting a setting of one or more communication link controls at the first protocol layer occurs before the communication link begins operation.

4. The method of claim 1 , further comprising adjusting a setting of one or more communication link controls of the second protocol layer to affect communication link quality at the second protocol layer.

5. The method of claim 1 , further comprising computing a link quality reduction indicator that quantifies an effect of the specific type of disruption at the first protocol layer on the quality of the communication link as characterized by the metrics reported by the second protocol layer.

6. The method of claim 1 , further comprising calculating a best attainable quality indicator that quantifies a best line quality capable for the communication link.

7. The method of claim 1 , further comprising computing tradeoffs between two or more metrics associated with performance of the communication link at the first protocol layer; and using the mapping between the communication link performance at the first protocol layer and the quality of the communication link at the second protocol layer to translate the computed tradeoffs to tradeoffs between two or more metrics associated with the quality of the communication link at the second protocol layer.

8. The method of claim 1 , further comprising calibrating a relationship between disruptions at the first protocol layer and quality of the communication link as characterized by metrics reported by the second protocol layer.

9. The method of claim 8 , wherein the calibrating occurs before the communication link is in operation.

10. The method of claim 8 , wherein the calibrating includes intentionally introducing disruptions to the performance of the communication link at the first protocol layer while monitoring effects of the disruptions on the quality of the communication link as characterized by metrics reported by the second protocol layer.

11. The method of claim 1 , wherein the second protocol layer is an application layer.

12. A non-transitory computer readable persistent storage medium for controlling a performance of a communication link in a communication system, the storage medium comprising:

a computer readable persistent storage medium having computer readable program code embodied therewith, the computer readable program code comprising:

computer readable program code that, if executed, maps performance of a communication link, as characterized by metrics reported by a first protocol layer in a network device, to quality of the communication link, as characterized by metrics reported by a second protocol layer in the network device, the second protocol layer being higher than the first protocol layer in a protocol stack running on the network device;

computer readable program code that, if executed, adjusts a setting of one or more communication link controls at the first protocol layer to attain a given communication link performance at the first protocol layer that, according to the mapping between the communication link performance at the first protocol layer and the quality of the communication link at the second protocol layer, corresponds to a target quality of the communication link at the second protocol layer; and

computer program code that, if executed inserts a specific type of disruption in a physical layer associated with the first protocol layer and observing an effect of the specific type of disruption on quality of the communication link of the second protocol layer.

13. The storage medium of claim 12 , wherein the computer readable program code that, if executed, adjusts the setting of one or more communication link controls at the first protocol layer includes computer readable program code that, if executed, adjusts the setting of one or more communication link controls at the first protocol layer dynamically while the communication link is in operation.

14. The storage medium of claim 12 , wherein the computer readable program code that, if executed, adjusts the setting of one or more communication link controls at the first protocol layer includes computer readable program code that, if executed, adjusts the setting of one or more communication link controls at the first protocol layer before the communication link begins operation.

15. The storage medium of claim 12 , further comprising computer readable program code that, if executed, adjusts the setting of one or more communication link controls of the second protocol layer to affect communication link quality at the second protocol layer.

16. The storage medium of claim 12 , further comprising computer readable program code that, if executed, computes a link quality reduction indicator that quantifies an effect of the specific type of disruption at the first protocol layer on the quality of the communication link as characterized by the metrics reported by the second protocol layer.

17. The storage medium of claim 12 , further comprising computer readable program code that, if executed, calculates a best attainable quality indicator that quantifies a best line quality capable for the communication link.

18. The storage medium of claim 12 , further comprising computer readable program code that, if executed, computes tradeoffs between two or more metrics associated with performance of the communication link at the first protocol layer; and

using the mapping between the communication link performance at the first protocol layer and the quality of the communication link at the second protocol layer to translate the computed tradeoffs to tradeoffs between two or more metrics associated with the quality of the communication link at the second protocol layer.

19. The storage medium of claim 12 , further comprising computer readable program code that, if executed, calibrates a relationship between disruptions at the first protocol layer and quality of the communication link as characterized by metrics reported by the second protocol layer.

20. The storage medium of claim 19 , wherein the computer readable program code that, if executed, calibrates a relationship between disruptions at the first protocol layer and quality of the communication link as characterized by metrics reported by the second protocol layer includes computer readable program code that, if executed, intentionally introduces disruptions to the performance of the communication link at the first protocol layer while monitoring effects of the disruptions on the quality of the communication link as characterized by metrics reported by the second protocol layer.

21. The storage medium of claim 12 , wherein the second protocol layer is an application layer.

22. A communication system, comprising:

memory storing computer readable program code; and

a processor capable of running the computer readable program code stored in the memory, the computer readable program code, if executed:

mapping performance of a communication link, as characterized by metrics reported by a first protocol layer in a network device, to quality of the communication link, as characterized by metrics reported by a second protocol layer in the network device, the second protocol layer being higher than the first protocol layer in a protocol stack running on the network device; and

adjusting a setting of one or more communication link controls at the first protocol layer to attain a given communication link performance at the first protocol layer that, according to the mapping between the communication link performance at the first protocol layer and the quality of the communication link: at the second protocol layer, corresponds to a target quality of the communication link at the second protocol layer; and

inserting a specific type of disruption in a physical layer associated with the first protocol layer and observing an effect of the specific type of disruption on quality of the communication link of the second protocol layer.

23. The system of claim 22 , further comprising a dynamic line management system that adjusts the setting of one or more communication link: controls of the first protocol layer dynamically while the communication link is in operation.

24. The system of claim 22 , wherein the computer readable program code includes computer readable program code that, if executed, adjusts the setting of one or more communication link: controls at the first protocol layer before the communication link begins operation.

25. The system of claim 22 , wherein the computer readable program code further includes computer readable program code that, if executed, adjusts the setting of one or more communication link controls of the second protocol layer to affect communication link quality at the second protocol layer.

26. The system of claim 22 , wherein the computer readable program code further includes computer readable program code that, if executed, computes a link: quality reduction indicator that quantifies an effect of the specific type of disruption at the first protocol layer on the quality of the communication link as characterized by the metrics reported by the second protocol layer.

27. The system of claim 22 , wherein the computer readable program code further includes computer readable program code that, if executed, calculates a best attainable quality indicator that quantifies a best line quality capable for the communication link.

28. The system of claim 22 , wherein the computer readable program code further includes computer readable program code that, if executed, computes tradeoffs between two or more metrics associated with performance of the communication link at the first protocol layer; and using the mapping between the communication link: performance at the first protocol layer and the quality of the communication link at the second protocol layer to translate the computed tradeoffs to tradeoffs between two or more metrics associated with the quality of the communication link: at the second protocol layer.

29. The system of claim 22 , wherein the computer readable program code further includes computer readable program code that, if executed, calibrates a relationship between disruptions at the first protocol layer and quality of the communication link as characterized by metrics reported by the second protocol layer.

30. The system of claim 29 , wherein the computer readable program code that, if executed, calibrates a relationship between disruptions at the first protocol layer and quality of the communication link as characterized by metrics reported by the second protocol layer further includes the computer readable program code that, if executed, intentionally introduces disruptions to the performance of the communication link at the first protocol layer while monitoring effects of the disruptions on the quality of the communication link as characterized by metrics reported by the second protocol layer.

31. The system of claim 22 , wherein the second protocol layer is an application layer.