Using PTP for Time and Frequency in Broadcast Applications Part 2: PTP Clock Characteristics

Tech Review 2019

Using PTP for Time and Frequency in Broadcast Applications Part 2: PTP Clock Characteristics

This is the second part of a series describing the use of the Precision time Protocol (PTP), for the broadcasting industry.

Open file (pdf, 0.5 MB)

In this part the Master election process is described in more detail, focusing on the different states a PTP device, or to be more precise, a PTP port can assume. Of course, this paper is by no means intended to serve even as very basic guideline for actually designing a PTP stack, however, it is crucial to know about the wanted and unwanted states that devices in a PTP network can switch to transiently or remain in indefinitely.

After briefly touching on the concept of PTP ports the PTP states with their respective transitions are explained in detail for different classes of PTP devices. This paper concludes with comparing PTP enabled network devices and finally with describing the basic building blocks of a PTP software stack.