Protection switching using performance metrics

1. A method to trigger protection switching on a first link of a protection switching capable network device, comprising:

monitoring one or more performance metrics on said first link in said network device;

sending a signal failed message when at least one metric of said one or more performance metrics fails to satisfy performance criteria related to the at least one metric of said one or more performance metrics;

triggering a protection switching event from said first link to a second link in said network device in response to said signal failed message;

setting a first timer to wait a first predetermined time then monitoring the one or more performance metrics on said first link; and

setting a second timer to wait a second predetermined time then clearing the protection switching event.

2. The method of claim 1 further comprising monitoring a link status of said first link and sending the signal failed message when the link status is failed.

3. The method of claim 1 wherein the performance criteria comprises a threshold.

4. The method of claim 3 wherein the one or more performance metrics comprises average delay, wherein the at least one metric fails to satisfy the performance criteria when the average delay exceeds the threshold.

5. The method of claim 3 wherein the one or more performance metrics comprises packet loss wherein the at least one metric fails to satisfy the criteria when the packet loss exceeds the threshold.

6. The method of claim 3 wherein said first link comprises an Ethernet link.

7. The method of claim 1 further comprising refraining from responding to continuity check messages when the at least one metric of said one or more performance metrics fails to satisfy performance criteria related to the at least one metric of said one or more performance metrics.

8. The method of claim 1 wherein clearing the protection switching event comprises returning network traffic to said first link.

9. The method of claim 1 wherein clearing the protection switching event comprises network traffic remaining on said second link.

10. The method of claim 8 further comprising, after the first predetermined time, determining that said one or more performance metrics fails to satisfy performance criteria and resetting the first timer to wait a third predetermined time.

11. A network device with one or more links that are part of a network supporting protection switching, comprising:

a processor;

one or more computer readable, non-transitory, tangible storage media;

program instructions stored on the one or more computer readable storage media for triggering protection switching on a first link of the one or more links with a degraded performance metric that, when executed by said processor, direct said processor to at least:

monitor one or more performance metrics on said first link of the one or more links that are part of the network;

send a signal failed message when at least one performance metric of said one or more performance metrics fails to satisfy a predetermined performance criteria related to the at least one performance metric of said one or more performance metrics; and

trigger a protection switching event from said first link to a second link of the one or more links that are part of the ring network in response to said signal failed message;

set a first timer to wait a first predetermined time then monitor the one or more performance metrics on said first link; and

set a second timer to wait a second predetermined time then clear the protection switching event.

12. The network device of claim 11 wherein the processor reads and executes the program instructions, wherein the program instructions further direct the processing system to monitor a link status and send the signal failed message when the link status is failed.

13. The network device of claim 11 wherein the predetermined performance criteria comprises a threshold and wherein the at least one performance metric fails to satisfy the predetermined performance criteria when the at least one performance metric falls below, exceeds, or meets the threshold.

14. The network device of claim 13 wherein the one or more predetermined performance metrics comprises average delay.

15. The network device of claim 13 wherein the one or more predetermined performance metrics comprises packet loss.

16. The network device of claim 13 wherein the first link comprises an Ethernet link.

17. The network device of claim 11 wherein the program instructions further direct the processor to refrain from responding to continuity check messages when the at least one metric of said one or more performance metrics fails to satisfy performance criteria related to the at least one metric of said one or more performance metrics.

18. The network device of claim 11 wherein clearing the protection switching event comprises returning network traffic to said first link.

19. The network device of claim 11 wherein clearing the protection switching event comprises network traffic remaining on said second link.

20. The network device of claim 18 further comprising, after the first predetermined time, determine that said one or more performance metrics fails to satisfy performance criteria and reset the first timer to wait a third predetermined time.