std chrono time synchronization

I need to send some data over network with timestamps, this time should have high precision. Looking at std::chrono clocks I found out that std::chrono::*_clock::now() returns time_point which is depends at clock's epoch. I failed to find out which epoch is used in each clock and which of them can be used safely when sended wia network. For example on windows high_resolution_clock is wrapper around QueryPerformanceCounter it has good precision, but, I think, useless as timestamp for network tasks.

So question is how to "synchronize" high resolution clock over network?