008: The second version improves accuracy, precision, and robustness but is not backward compatible with the original 2002 version. It is also better adapted to wide-area de- ployments and introduces extensibility through the concept of PTP profiles. IEEE 1588-2019: Five years later, in June 2013, a project was authorized to revise the IEEE- 2008 standard to improve security of PTP and also provide an implementation for applications needing sub-nanosecond time accuracy. In November 2019, the IEEE published IEEE 1588- 2019, informally known as PTPv2.1, which was designed to be fully backward compatible with IEEE 1588-2008. Currently, the P1588 Working Group is working on six additional projects, approved by the IEEE SA, to amend IEEE Std 1588-2019. These projects are described in what the IEEE calls project au- thorization requests (PARs) and are known by the titles P1588a through P1588g. These projects are expected to complete through the end of 2022. Consult https://sagroups.ieee.org/1588/active-pro- jects/ for details on these amendments. This standards-based method for synchronizing clocks is cost effective, supports heterogenous net- works, and provides nanosecond-level synchronization precision for clock distribution. Nowadays, PTP is applied to a large array of different application areas including test and measurement, indus- trial automation, power industry, telecommunications, aerospace and automobile, audio-video dis- tribution, and SO on. Note that none of the three releases of the IEEE 1588 standards, PTPv1, PTPv2, or PTPv2.1, are part of the Ethernet specifications. Chapter 7 discusses PTP and all the major profiles in detail. 4.3.1 IEEE TSN The Time-Sensitive Networking (TSN) Task Group (TG) (part of IEEE 802.1 Working Group) is responsible for a subset of standards under the umbrella of the IEEE 802 LAN/MAN Standards Committee. IEEE 802.1 TSN focuses on enhancing IEEE Ethernet standards to address cross-in- dustry requirements for applications that are time-sensitive. The TSN Task Group (TG) has ev