The real-world challenges of trying to upgrade time-synchronization without TimeKeeper are described in an excellent 2012 technical paper about a project at the company IMC Global Finance [IMC]. The article documents a two year, highly resourced project run by an
Challenges deploying PTPv2 in a Global Financial company
Interesting article – most of these problems and more were solved in TimeKeeper years ago. But the most interesting part is the enormous engineering effort required to kind of get PTP to work.