Chapter 9. PTP Deployment Considerations In this chapter, you will learn the following: Deployment and usage: Covers the specifics of sourcing timing signals and carrying them across a packet network for both the frequency and phase/time use cases. For the case of fre- quency, it covers using both PTP and non-PTP methods and points out the appropriate solution to use in different scenarios. For the phase/time scenario, it explains a range of issues that one must consider, including capabilities of the network. Factors impacting timing performance: Covers the issues that must be dealt with to produce an accurate and robust solution. This includes the timing performance of the PTP clocks and the influence of packet delay variation (PDV) and asymmetry on the phase/time recovered at the end of the timing chain. Parameters for timing performance: Builds upon the introductory theory in "Chapter 5. Clocks, Time Error, and Noise", to show how the performance parameters must be controlled to deliver an accurate timing signal. Clock performance: Extends the coverage in previous chapters about the characteristics of sev- eral types of frequency and phase/time clocks. Deals with each category of performance and shows how it affects the design and deployment. Budgeting end-to-end time error: Covers the factors that apply to the end-to-end performance, and specifically examines how to budget end-to-end time error. Network holdover: Shows what holdover can do for a synchronization design and what it is not able to do. Packet network topologies: Discusses the influence that many common packet technologies can have on the timing design and how to mitigate the consequences of how they function. Packet transport: Examines the effect of different transport types on the transport of timing signals and what must be done to mitigate and minimize their ability to alter the time signal and degrade the accuracy. Non-mobile deployments: Examines a couple of alternative deployment cases such as the cable industry and other industrial uses s