A rttMonTimeoutNotification indicates the occurrence of a timeout for a RTT operation, and it indicates the clearing of such a condition by a subsequent RTT operation. Precisely, this has resulted in rttMonCtrlOperTimeoutOccurred changing value. When the RttMonRttType is 'pathEcho', this notification will only be sent when the timeout occurs during an operation to the target and not to a hop along the path to the target. This also applies to the clearing of the timeout. If History is not being collected, the instance values for the rttMonHistoryCollectionAddress object will not be valid. When RttMonRttType is not 'echo' or 'pathEcho' the rttMonHistoryCollectionAddress object will be null. rttMonTimeoutNotification object is superseded by rttMonNotification.