microsoft/SDN

can someone explain why windows PTP client doesn't work with linux ptp server?

AndreV84 opened this issue · 15 comments

any help with the subject?

I am getting progress with understanding details; MMoreover with wireshark I can see frequent sync packages from GM ptp4l that has argument TIMESCALE & UTC REasonable passed; But the w32tm / resync won't work;
What does the reply @dahavey mean? Could you extend, please?

@dcuomo @dahavey
Could you help out with the issue, please?
or direct to someone who would help with it, please?

Are you using unicast or multicast? Software timestamping or Hardware Timestamping mode on ptp4l?

tried hardware timestamping on linux ptp4l server
that would synchronize with GPS PPS PTP

I was never able to get a definitive answer, but I don't think Windows exposes any API with regards to hardware timestamping, so I assume the ptp client just doesn't work in HW mode.

If you look at this link: , https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwibtfO_7s3uAhVrUhUIHZMEChkQFjAAegQIAxAC&url=https%3A%2F%2Ftechcommunity.microsoft.com%2Fgxcuf89792%2Fattachments%2Fgxcuf89792%2FNetworkingBlog%2F172%2F2%2FEvolution%2520of%2520Timekeeping%2520in%2520Windows.pdf&usg=AOvVaw0MFTjhs-fz427kHAsmC5Gi

With the goal of taking time sync accuracy to the next level, we have included Software Timestamping, Leap Second support and a client for the Precision Time Protocol (PTP) in the Server2019 release. We continue to focus on enabling further time accuracy improvements through PTP and new features like Hardware Timestamping and other innovations.

It sounds like it's something they're planning, but not currently present in Windows.

The alternative is to run it in SW mode, but that changes the flags you mentioned and for some reason Microsoft decided the client won't work with arbitrary timescales.

if server [ptp4l] Linux computer has hardware timestamp that doesn't exclude software timestamp clients [e.g. windows PC] , right?

so I am trying to get " client for the Precision Time Protocol (PTP) " at Windows side
while the Linux acts as a Server using hardware timestamp on its ethernet interface

Good morning, Windows hardware timestamping is being documented as we speak. The documentation is scheduled to be released in a few months. I will update the thread if there is any change to the scheduling.

@dahavey In the meantime, could you give us a definitive yes/no answer whether Windows currently supports HW time-stamping?

Well, I really can't comment on future products, but I have already said that it's being documented.

I'll take 'future product' as a no then.

@dahavey Thank you for following up!
But as for now it is also a challenge to run Windows PTP client with software timestamp using ptp4l Linux server.
while linuxptp pre-defined config files do the trick getting the windows to synchronize with linux server linuxptp software, we were never able to get true positive using winows ptp client with Linux ptp4l server [ that is maintained by the other author]
So the question if you could confirm Windows PTP client to work with Linux ptp4l server at all.

Hi @AndreV84, I don't know. I forwarded the question along to the dev team.