Re: nanosecond timestamp

[Darren Reed <darrenr () reed wattle id au>]

In some email I received from Guy Harris, sie wrote:
> On Dec 9, 2004, at 2:08 PM, Darren Reed wrote:
>
> > In some email I received from Guy Harris, sie wrote:
> > > BTW, where are you getting the nanosecond-resolution time stamps in
> > > Solaris?
> >
> > gethrtime
>
> That says what the high-resolution time counter's value is now, not 
> what the value was when bufmod saw the packet (which raises another 
> issue, namely that the time stamps you get out of libpcap might have 
> nanosecond *precision* but they might not have nanosecond *accuracy*) - 
> or are the packets in question not being captured by libpcap, so that 
> you can use "gethrtime()" to time stamp packets reasonably close to the 
> time t which they arrived?

I think that whether it is bufmod or a program that generates a time
stamp, it is still a software timestamp and sometime after the actual
packet "arrived".

So what am I trying to say here?  Unless you have hardware timestamps
in captured packets, one software timestamp is as good as the next in
a well written application.

Darren
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