ptpd version with kernel send time stamps - synchronization improvements

[Patrick Ohly]

On Fr, 2010-01-29 at 17:15 +0000, gertjan hofman wrote:
> We didn't change any of the time stamping mechanism but found that we
> could get improvement by taking a closer look at the filtering applied
> to the Master to Slave Delay etc.  Especially with store and forward
> switches,  it is not obvious to me that the kernel time stamping is
> the dominating factor in the time synchronization.

Hardware time stamping on the host definitely led to a measurable
improvement:
http://www.linuxclustersinstitute.org/conferences/archive/2008/PDF/Ohly_92221.pdf

But I agree, delays inside the network are more likely to affect the
results, which is why PTP v2 support in ptpd and v2 enabled switches are
important. I'm sure your traffic prioritization also helps.

-- 
Best Regards, Patrick Ohly

The content of this message is my personal opinion only and although
I am an employee of Intel, the statements I make here in no way
represent Intel's position on the issue, nor am I authorized to speak
on behalf of Intel on this matter.