ion, such as the calculated mean path delay (section 8.2.2). Parent dataset or parentDS: Attributes describing the parent (the clock to which the clock synchronizes) and the grandmaster clock at the root of the converged master-slave hierarchy (section 8.2.3). The values for members of this dataset (such as clockClass) are set by the grandmaster based on its source of time and transmitted to the current PTP clock with An- nounce messages via any boundary clocks. The intervening boundary clocks may update some values (such as stepsRemoved) when they create their Announce messages to downstream slave ports. Time properties dataset or timePropertiesDS: Attributes of the timescale including informa- tion about the UTC offset and details of upcoming leap second events (section 8.2.4). Foreign master dataset or foreignMasterDS: Data describing a foreign master from the grandmaster fields of a received Announce message (an example is the clock quality fields of the grandmaster). Port dataset or portDS: A separate dataset for every port that contains the attributes of that port, including the PTP state (section 8.2.5). An example of a single member of the default dataset, namely the clock class of the clock, is defaultDS.clockQuality.clockClass Members of the datasets can have static values (fixed by the profile, the protocol, or some inherent properties). They can also be dynamic, as a result of the oper- ation of the PTP clock mechanisms or the PTP protocol, or they can be configurable, meaning se- lected by the operator. Obviously, the members of the current dataset are always dynamic since the values update based on the operation of the PTP clock. The Parent and Time Properties datasets are also dynamic as they are based on data from the up- stream master and ultimately the attributes of the grandmaster. These datasets are filled in for the current clock with Announce messages from the upstream master. Table 7-5 shows an example of a member or two from each dataset. Table 7-5 Example Dataset Members Member Name Value