Switch of notification. Determine whether and how to send notifications for the test instance: - probeFailure(0) - Generate a PathChange notification when the current path varies from a previously determined path. - testFailure(1) - Generate a TestFailed notification when the full path to a target can't be determined. - testCompletion(2) - Generate a TestCompleted notification when the path to a target has been determined. - overRtdThreshold(3) - Generate a Overthreshold of RTD notification when the statistic results exceed threshold. - overOwdThresholdSd(4) - Generate a Overthreshold of OWD-SD notification when the statistic results exceed threshold. - overOwdThresholdDs(5) - Generate a Overthreshold of OWD-DS notification when the statistic results exceed threshold. - overJitterThresholdSd(6) - Generate a Overthreshold of Jitter-SD notification when the statistic results exceed threshold. - overJitterThresholdDs(7) - Generate a Overthreshold of Jitter-DS notification when the statistic results exceed threshold. - resultChangePacked(9) - Generate a packed trap when test result is changed. No more than two traps will be sent in one second and each trap contains at most ten records. The value #0x00 indicates disable all notifications.