es sections on devices that monitor the network time (probes) as well as field testing remote devices to isolate any faults. There is also a section on understanding the finer points of GNSS receivers and troubleshooting. 12.1 Hardware and Software Solution Requirements Requirements for timing transfer are evolving toward improved precision and accuracy. And that means the timing distribution networks must be designed carefully SO that the timing signal meets the overall synchronization requirements after crossing numerous network nodes and under a wide range of network conditions. Even when the networks are designed properly to carry timing information, special design consider- ations are required for the equipment transporting the clock synchronization. Engineering this equipment to provide synchronization services starts with selecting the right hardware components and designing to minimize any systematic loss of accuracy. This section covers what goes into the construction of a PTP-aware node and how these compon- ents are combined to meet the performance goals of the node. There is more to making a good PTP clock beyond just gluing a few off-the-shelf parts together. It requires the mating of good hardware to feature-rich software and connecting it all together into a system that minimizes time error (TE) and maximizes the desired performance. Making a good PTP clock also requires a good track record from the component vendors making the individual timing components, skill from the software engineers controlling it all, and, most of all, experience of the hardware designers who decide how to put it all together. It is this combina- tion of components, skills, and experience that turns loose pieces of steel, quartz, and silicon into a very precise clock. The quality of the implementation makes a huge impact, SO the reputation and past performance of the clock vendor matters. Given these factors, it is very much worth looking at the details of what is involved in a well-designed PTP clock, and how the major pi