Method and apparatus for providing availability metrics for measurement and management of ethernet services

1. A method of monitoring availability in an Ethernet network, the method comprising the steps of:

associating performance thresholds with a maintenance entity defined between flow points on the Ethernet network;

measuring performance parameters of the maintenance entity for a time interval, the performance parameters including frame metrics; and

comparing one or more of the measured performance parameters to the performance thresholds to determine an availability metric of the maintenance entity.

2. The method of claim 1 , wherein the frame metrics are selected from a group including Frame Loss Ratio (FLR), Frame Delay (FD) and Frame Delay Variation (FDV).

3. The method of claim 2 , wherein the performance thresholds are selected from a group including an Errored Second Threshold, a Severely Errored Second Threshold and an Unavailability Threshold.

4. The method of claim 3 , wherein the availability metric is an Errored Second, wherein the time interval is a second, and wherein the method includes the step of determining that the second is an Errored Second if any one of the measured FLR, FD and FDV frame metrics exceed their associated Errored Second Threshold.

5. The method of claim 4 , wherein the step of determining whether the second is an Errored Second includes the step of determining that at least one the measured FLR, FD and FDV frame metrics that exceeds its associated Errored Second Threshold is also less than its associated Severely Errored Second Threshold.

6. The method of claim 3 , wherein the availability metric is a Severely Errored Second, wherein the time interval is a second, and wherein the second is a Severely Errored Second if any one of the measured FLR, FD and FDV frame metrics exceed their associated Severely Errored Second Threshold.

7. The method of claim 6 , including the step of determining that the second is an Unavailable Second responsive to either the previous second being an unavailable second or a N previous consecutive seconds being Severely Errored Seconds.

8. The method according to claim 7 including the step of updating an Unavailability Time (UAT) metric in response to the detection of an Unavailable Second.

9. The method according to claim 6 , further including the step of updating an Available Time (AT) metric in response to N consecutive determinations that a second is not a Severely Errored Second.

10. The method according to claim 4 , wherein an availability measurement interval includes a plurality of the time intervals, and further including the step of determining, for each availability measurement interval, an Errored Second Ratio (ESR) representing a number of Errored Seconds in the availability measurement interval.

11. The method according to claim 6 , wherein an availability measurement interval includes a plurality of the time intervals, and further including the step of determining, for each availability measurement interval, a Severely Errored Second Ratio (SESR) representing a number of Severely Errored Seconds in the availability measurement interval.

12. The method according to claim 8 , wherein an availability measurement interval includes a plurality of the time intervals, and further including the step of determining, for each availability measurement interval, an Unavailability Ratio (UAR) representing a ratio of UAT to the availability measurement interval.

13. The method according to claim 9 , wherein an availability measurement interval includes a plurality of the time intervals, and further including the step of determining, for each availability measurement interval, an Availability Ratio (AR) representing a ratio of AT to the availability measurement interval.

14. The method according to claim 8 , wherein an availability measurement interval includes a plurality of the time intervals, and further including the step of determining an Outage Intensity (OI) metric reflecting a number of periods of UAT during the availability measurement interval.

15. A network device comprising: a processor, operations and maintenance (OAM) program code stored on a computer readable medium, the OAM program code operable when executed by the processor to collect availability metrics in an Ethernet network by: associating performance thresholds with a maintenance entity defined between flow points on the Ethernet network, measuring performance parameters of the maintenance entity for a time interval the performance parameters including frame metrics; and comparing one or more of the measured performance parameters to the performance thresholds to determine an availability metric of the maintenance entity.

16. The network device of claim 15 , wherein the frame metrics are selected from a group including Frame Loss Ratio (FLR), Frame Delay (FD) and Frame Delay Variation (FDV).

17. A network device comprising: a processor, operations and maintenance (OAM) program code stored on a computer readable medium, the OAM program code operable when executed by the processor to collect availability metrics in an Ethernet network by: associating performance thresholds with a maintenance entity defined between flow points on the Ethernet network; the performance thresholds are being selected from a group including an Errored Second Threshold, a Severely Errored Second Threshold and an Unavailability Threshold; measuring performance parameters of the maintenance entity for a time interval; and comparing one or more of the measured performance parameters to the performance thresholds to determine an availability metric of the maintenance entity.

18. The network device of claim 16 , wherein the OAM program code is further operable, when executed, to calculate at least one of an Unavailable Time (UAT), Available Time (AT), Errored Second Ratio (ESR), Severely Errored Second Ratio (SESR), Unavailability Ratio (UAR), Availability Ratio (AR) and Outage Intensity (OI) responsive to the FLR, FD, FDV and performance thresholds.