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
Time Maps in Action
This shows a time map for a client (center) that is getting NTP time from a variety of standard internet NTP servers and via a customer site (to the left). A TimeKeeper Pocket GrandMaster (bottom left) is serving multiple Stratum