perfSONAR User Q&A and Other Discussion

[Boote Jeff <>]

I don't know what you mean by 'i have check the source and destinaion clock'. 
I don't see any ntp information listed here, which is what you would need in 
order to know how well synchronized your clocks are.

If you get negative latencies, it is almost always because your source clock 
is ahead of your destination clock. They might even both be synchronized, but 
if the latency between them is smaller than the error in those clocks you can 
get negative values. The only way to know is by looking at the error bounds 
of your synchronization. Look at NTP error estimates.

Jeff

On Jun 22, 2012, at 1:53 AM, Matt Crawford wrote:

> Hi,
> when i show perfSONAR One Way Latency graph , There are negative latency 
> results in the data.
> but i have check the source and destination clock 
> 
> source : 
> # clock
> Fri 22 Jun 2012 03:34:12 PM CST  -0.017119 seconds
> 
> destination :
>  #clock
> Fri 22 Jun 2012 03:34:15 PM CST  -0.016857 seconds
> 
> 
> why am i get the negative latency results in the data ?
> Any suggestions as to what might be wrong?
> 
>  
> As always, thanks for your help!
> 
>