pdhCurrentDataUnidirectional — ETSI published formal attachments
The pdhCurrentDataUnidirectional class is used to define generic characteristic for unidirectional PDH performance monitoring from which subclasses are defined in order to hold performance event counts for a specific monitoring point. Subclasses of this class are used in order to support performance monitoring of PDH trails at various layers as described in EN 300 417-5-1 [10] . The performance monitoring events ES, SES and BBE which are monitored by some of the subclasses of this subclass are defined in annex B/G.826 [11] and are based on the performance event primitives specified in EN 300 417-1-1 [9] and EN 300 417-5-1 [10] . The granularityPeriod attribute can only be assigned a value at creation time. This class can only contain one reference to an instance of the thresholdData object class in the thresholdDataInstance attribute. If a threshold is reached or crossed then the currentProblemList attribute shall indicate it with the probable cause thresholdCrossed. Subclass of this class is used to monitor the near-end or far-end performance data of the trail. A period of unavailable time begins at the onset of 10 consecutive SES events. These ten seconds are considered to be part of unavailable time. A new period of available time begins at the onset of ten consecutive non-SES events. These ten seconds are considered to be part of available time. The unavailability conditions are kept separate for near end and far end monitoring. This means that near end unavailability is deduced from near end conditions only (e.g. 10 consecutive SES at the near end) and far end unavailability is deduced from far end conditions only (e.g. 10 consecutive SES at the far end). For threshold reset subclasses of this object class the following rules apply: No more than one QOS alarm shall be generated until there has been a 15 minutes rectangular fixed window with less error count than the low error count threshold and no unavailable period exists. To provision the high and low threshold value, the counterThresholdAttributList attribute of the ITU-T Recommendation Q.822 [6] thresholdDataInstance is used. In this attribute all the thresholds (high and low) for each necessary counter are stored in a list. This means for example, that the high threshold for ES and the low threshold for ES are individually stored in the same list. It is up to the network element to recognize which is the high and which is the low one. If the unavailableTimeAlarmPackage is present and if an unavailable period starts then a communication alarm shall be sent with a probable cause of Unavailable and the presence of this unavailable condition is indicated by the currentProblemList attribute. If an unavailable period is ending then a communication alarm shall be sent with a probable cause of Unavailable and a severity of Cleared. An available condition is indicated by the absence of the unavailable condition in the current problem list. The unavailable condition has no effect on the operationalState. Each subclass of this class shall define the performance attributes required to hold the mandatory or optional performance events. These performance event counts (except UAS) are inhibited during unavailable time of its own direction (at the near end or at the far end). Attributes which are defined in a subclass of this class shall be included in history information using the historyData, or one of its subclass, unless it is explicitly specified in the subclass of this class that a particular attribute be not included. Each subclass of this class shall indicate which subclass of the history data is used for history retention. The following conditional packages are not used in this class: filterSuppressionPkg, observedManagedObjectPkg. Concerning the subclasses of this class the following rule applies: If a subclass of this class has a granularity period of 15 minutes, it should be either an instance with the threshold reset functionality or an instance without this functionality instantiated (per termination point), but not both.