PTP is the “Precision Time Protocol”, which is defined in IEEE 1588. In contrast to NTP, this is a network protocol, which is characterized by significantly higher accuracies (down to the nanosecond range) and is usually used in locally limited networks (e.g. measurement / control / regulation technology, automation technology, etc.).
In the foreground is not the absolutely correct time information, but rather the high-precision “clocking” of interconnected devices in such industrial or computer networks. In connection with the PTP network organization and clock types, one speaks initially of Grandmaster Clocks (best possible reference device) and Boundary Clocks (devices with master and slave function), whose role distribution is determined using the best Master Clock algorithm. On the other hand, clearly defined roles are assigned to the ordinary clocks (either as master or clients), so-called transparent clocks then only forward the PTP time stamp when corrected. The runtime correction is ensured using complex computing algorithms. So it is not the case that one procedure is to be replaced by the other: NTP and PTP have different functional focuses, which is why both will continue to have authorization in the future and can also be used in parallel in computer networks if necessary.