[徐鸿 <icehong@xxxxxxxxx>]

Thanks for the reply !
I got accurate result from string.format("%f",b)),   and got that precision of floating point number.   Many thanks !

2014-11-21 6:55 GMT+08:00 Guy Harris <guy@xxxxxxxxxxxx>:

On Nov 20, 2014, at 2:43 PM, John Sullivan <jsethdev@xxxxxxxxxxxxxxxxxxxx> wrote:

> The second part of the answer involves the meaning of a nanosecond
> precision packet timestamp.

Especially given that there isn't necessarily a guarantee that the time stamps reflect the exact arrival time of the first bit - or the last bit - of the packet at the receiver's network adapter, or that it reflects *anything* other than the time when the hardware, software, or firmware that timestamps the packet first sees the packet (which could be at some point in the host networking stack).