Method and apparatus for measurement of service disruption interval

1. A method comprising:

setting a high threshold equal to a bit-error rate threshold of a network element in a network under test;

generating a test signal;

supplying the test signal to an input of the network under test;

receiving the test signal, exhibiting a bit-error rate, from an output of the network under test;

designating, as the start time of a service disruption, a time when the bit-error rate of the received test signal exceeds the high threshold;

designating, as the start time of a measured settling period, a time when the bit-error rate of the received test signal falls to a pre-set low threshold;

after the measured settling period start time, designating, as a measured settling period, a time period during which the received bit-error rate remains equal to or below the low threshold;

designating, as the end time of the service disruption, a time when the measured settling period reaches a pre-set settling period;

designating, as the determined service disruption interval, the time difference between the service disruption start time and the service disruption end time; and

outputting the determined service disruption interval.

2. The method according to claim 1 , wherein the network under test comprises an optical transport network.

3. The method according to claim 1 , wherein outputting the determined service disruption interval further comprises:

outputting the determined service disruption interval in a viewable format.

4. The method according to claim 1 , wherein the method further comprises:

upon receiving the test signal,

determining whether the bit-error rate in the received test signal exceeds the high threshold; and

so long as the bit-error rate does not exceed the high threshold, continuing to receive the test signal and determine whether the bit-error rate in the received test signal exceeds the high threshold, otherwise, proceeding to designate the start time of the service disruption.

5. The method according to claim 1 , wherein the method further comprises:

upon designating the start time of a service disruption, determining whether the bit-error rate has fallen to the pre-set low threshold; and

so long as the bit-error rate does not fall to the pre-set low threshold, continuing to determine whether the bit-error rate has fallen to the pre-set low threshold, otherwise proceeding to designate the start time of the settling period.

6. The method according to claim 1 , wherein the method further comprises:

upon designating the start time of the settling period, determining whether a time elapsed since the settling period start time has reached the pre-set settling period; and

so long as the time elapsed has not reached the pre-set settling period, determining whether the bit-error rate remains equal to or below the pre-set low threshold, otherwise proceeding to designate the end time of the service disruption.

7. The method according to claim 6 , wherein determining whether the bit-error rate is less than or equal to the pre-set low threshold further comprises:

if the bit-error rate remains less than or equal to the low threshold, returning to determine whether a time elapsed since the time designated as the settling period start time has reached the pre-set settling period, otherwise returning to receive the test signal, exhibiting a bit-error rate, from an output of the network under test.

8. An apparatus comprising:

a setting component configured to set a high threshold equal to a bit-error rate threshold of a network element in a network under test;

a generating component configured to generate a test signal;

a first output component configured to supply the generated test signal to an input of the network under test;

a receiving component configured to receive the test signal, exhibiting a bit-error rate, from an output of the network under test;

a service disruption start time designator configured to designate, as the start time of a service disruption, a time when the bit-error rate of the received test signal exceeds the high threshold;

a settling start time designator configured to designate, as the start time of a measured settling period, a time when the bit-error rate of the received test signal falls to a pre-set low threshold;

a settling period designator configured to designate the measured settling period as a time period from the start time of the measured settling period to a time period during which the received bit-error rate remains equal to or below the low threshold;

a service disruption end time designator configured to designate, as the end time of the service disruption, a time when the measured settling period reaches a pre-set settling period; and

a service disruption interval designator configured to designate, as a determined service disruption interval, the time difference between the service disruption start time and the service disruption end time; and

a second output component configured to output the determined service disruption interval.

9. The apparatus according to claim 8 , wherein the network under test comprises an optical transport network.

10. The apparatus according to claim 8 , wherein the second output component is further configured to output the determined service disruption interval in a viewable format.

11. The apparatus according to claim 8 , further comprising:

a high threshold checking component configured to determine whether the bit-error rate in the received test signal exceeds the high threshold, and send a signal to the service disruption start time designator to set the start of the service disruption interval if the bit-error rate exceeds the high threshold, otherwise, continuing to receive and determine whether bit-error rate exceeds the high threshold.

12. The apparatus according to claim 8 , further comprising:

a low threshold checking component configured to determine whether the bit-error rate has fallen to the pre-set low threshold, and send a signal to the settling period designator to set the start of the settling period, otherwise, continuing to determine whether the bit-error rate has fallen to the pre-set low threshold.

13. The apparatus according to claim 8 , further comprising:

a pre-set settling period checking component configured to determine whether a time elapsed since the settling period start time has reached the pre-set settling period, and sending a signal to a low threshold checking component to determine whether the bit-error rate has fallen to the pre-set low threshold, otherwise, sending a signal to the service disruption end time designator to set the end time of the service disruption.

14. The apparatus according to claim 13 , further comprising:

if the bit-error rate is less than or equal to the pre-set low threshold the pre-set settling period checking component continues determining whether the time elapsed since the time designated as the settling period start time has reached the pre-set settling period, otherwise, the low threshold checking component sends a signal to the receiving component to continue receiving test signals.

15. A method comprising the steps of:

setting a high threshold equal to a bit-error rate threshold of a network element in a network under test;

generating a first test signal;

supplying the first test signal to a first input of the network under test;

receiving the first test signal from a first output of the network under test;

generating a malfunction signal exhibiting a bit-error rate;

combining the malfunction signal with the first test signal received from the first output of the network under test, to create a second test signal exhibiting the bit-error rate;

supplying the second test signal exhibiting the bit-error rate to a second input of the network under test;

receiving the second test signal, exhibiting a bit-error rate, from a second output of the network under test;

designating, as the start time of a service disruption, a time when the bit-error rate of the received second test signal exceeds the high threshold;

designating, as the start time of a measured settling period, a time when the bit-error rate of the received second test signal falls to a pre-set low threshold;

after the measured settling period start time, designating, as a measured settling period, a time period during which the received bit-error rate remains equal to or below the low threshold;

designating, as the end time of the service disruption, a time when the measured settling period reaches a pre-set settling period;

designating, as a determined service disruption interval, the time difference between the service disruption start time and the service disruption end time; and

outputting the determined service disruption interval.

16. The method according to claim 15 , wherein the network under test comprises an optical transport network.

17. The method according to claim 15 , wherein outputting the designated service disruption interval further comprises:

outputting the determined service disruption interval in a viewable format.

18. The method according to claim 15 , wherein the method further comprises:

upon receiving the test signal from an output of the network under test,

determining whether the bit-error rate in the received test signal exceeds the high threshold; and

so long as the bit-error rate does not exceed the high threshold, continuing to receive the test signal and determine whether the bit-error rate in the received test signal exceeds the high threshold, otherwise, proceeding to designate the start time of the service disruption.

19. The method according to claim 15 , wherein the method further comprises the steps of:

upon designating the start time of a service disruption, determining whether the bit-error rate has fallen to the pre-set low threshold; and

so long as the bit-error rate does not fall to the pre-set low threshold, continuing to determine whether the bit-error rate has fallen to the pre-set low threshold, otherwise proceeding to designate the start time of the settling period.

20. The method according to claim 15 , wherein the method further comprises:

upon designating the start time of the settling period, determining whether a time elapsed since the time designated as the settling period start time has reached the pre-set settling period; and

so long as the time elapsed has not reached the pre-set settling period, determining whether the bit-error rate remains equal to or below the pre-set low threshold, otherwise proceeding to designate the end time of the service disruption.

21. The method according to claim 20 , wherein determining whether the bit-error rate is less than or equal to the pre-set low threshold further comprises:

if the bit-error rate remains less than or equal to the low threshold, returning to determine whether a time elapsed since the time designated as the settling period start time has reached the pre-set settling period, otherwise returning to receive the test signal, exhibiting a bit-error rate, from an output of the network under test.

22. An apparatus comprising:

a setting component configured to a high threshold equal to a bit-error rate threshold of a network element in a network under test;

a first generating component configured to generate a first test signal;

a first output component configured receive the first test signal and supply the first test signal to a first input of the network under test;

a first receiving component configured to receive the first test signal from a first output of the network under test;

a malfunction generating component configured to generate a malfunction signal exhibiting a bit-error rate;

a second generating component configured to generate a second test signal exhibiting the bit-error rate;

a second output component configured to receive the second test signal and supply the second test signal, exhibiting the bit-error rate, to a second input of the network under test;

a second receiving component configured to receive the second test signal, exhibiting the bit-error rate, from a second output of the network under test;

a service disruption start time designator configured to designate, as the start time of a service disruption, a time when the bit-error rate of the received test signal exceeds the high threshold;

a settling start time designator configured to designate, as the start time of a measured settling period, a time when the bit-error rate of the received test signal falls to a pre-set low threshold;

a settling period designator configured to designate the measured settling period as a time period from the start time of the measured settling period to a time period during which the received bit-error rate remains equal to or below the low threshold;

a service disruption end time designator configured to designate, as the end time of the service disruption, a time when the measured settling period reaches a pre-set settling period; and

a third output component configured to output, as a determined service disruption interval, the time difference between the service disruption start time and the service disruption end time.

23. The apparatus according to claim 22 , wherein the network under test comprises an optical transport network.

24. The apparatus according to claim 22 , wherein the third output component is further configured to output the determined service disruption interval in a viewable format.

25. The apparatus according to claim 22 , further comprising:

a high threshold checking component configured to determine whether the bit-error rate in the received test signal exceeds the high threshold, and send a signal to the service disruption start time designator to set the start of the service disruption interval if the bit-error rate exceeds the high threshold, otherwise, continuing to receive and determine whether bit-error rate exceeds the high threshold.

26. The apparatus according to claim 22 , further comprising:

a low threshold checking component configured to determine whether the bit-error rate has fallen to the pre-set low threshold, and send a signal to the settling period designator to set the start of the settling period, otherwise, continuing to determine whether the bit-error rate has fallen to the pre-set low threshold.

27. The apparatus according to claim 22 , further comprising:

a pre-set settling period checking component configured to determine whether a time elapsed since the time designated as the settling period start time has reached the pre-set settling period, and sending a signal to a low threshold checking component to determine whether the bit-error rate has fallen to the pre-set low threshold, otherwise, sending a signal to the service disruption end time designator to set the end time of the service disruption.

28. The apparatus according to claim 27 , further comprising:

if the bit-error rate is less than or equal to the pre-set low threshold, the pre-set settling period checking component continues determining whether the time elapsed since the time designated as the settling period start time has reached the pre-set settling period, otherwise, the low threshold checking component sends a signal to the receiving component to continue receiving test signals.