Hardware timestamp ?

[Pierre Karampournis <pkarampournis () gmail com>]

Hi,

I am currently working in a university lab and I need to capture packets 
with a nanosecond precision timestamp using the Pcap format.

Pcap format allows nanosecond timestamping (even if it is not 
implemented in libpcap yet) so I tried to modify libPcap and Tcpdump to 
realize that. But my first naive and ugly modification was erasing the 
kernel timestamp (currently in microseconds) by a user timestamp (in 
nanosecond of course) so I loose precision trying to gain precision...
Thinking about that, user timestamping is imprecise due to scheduling 
and other factors, but kernel timestamping, even if it is a lot better, 
isn't really accurate too.

So I read few things about using hardware timestamping and I wonder if 
something like that is being developed in libPcap or if solutions exists ?

With current networks bandwidth, why the time precision still isn't better ?

Thank you,

Pierre
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