[Guy Harris <guy@xxxxxxxxxxxx>]

On Thu, Nov 20, 2003 at 05:56:19PM +1100, Ronnie Sahlberg wrote:
> I think some versions of windows only provide 10ms or something like that
> accuracy.
> some versions of linux can provide sub ms accuracy depending on the CPU and
> how the kernel was compiled.

Note also the difference between "precision" and "accuracy".

An OS might have a very high-resolution clock, providing high-precision
time stamps.  However, packets aren't time-stamped the instant the first
octet, or the last octet, is processed by the network adapter (unless
the adapter does the time stamping).  Instead, they're time-stamped by
something in the OS code path between the point at which the host sees
the packet (which might be after the last octet is processed by the
adapter, due to interrupt latency, polling rather than per-packet
interrupting in order to batch packet arrival, etc.) and the point at
which it's delivered to the packet capture mechanism.