How does the IEEE1588 protocol work?

The basic function is that the most precise clock on the network synchronizes all other users. A clock with only one network port is termed an ordinary clock. There are two clocks, Master and Slave. In principle any clock can perform both the master and slave function.

The precision of a clock, more exactly stated of their time sources, is categorized by the protocol in classes (stratum). Here the highest class is an atomic clock which has the stratum value 1. The selection of the best clock in the network is performed automatically using the best master clock algorithm.

The precision of the synchronization depends very heavily on the network and the components used in the network. For this reason the transition over less deterministic components, e.g. routers and switches, is also made possible by the protocol using the boundary clock.

For the administration and configuration of clocks in the network, there is also a management protocol available.

PTP is based on IP multicast communication and is not restricted to Ethernet, but can be used on any bus system that supports multicasting. Multicast communication offers the advantage of simplicity; IP address administration does not need to be implemented on the PTP nodes. Furthermore, PTP can thus be scaled for a large number of PTP nodes.