[ntp:questions] ntp server help
mikel at irontec.com
Sat Aug 9 14:55:16 UTC 2008
David Woolley escribió:
> Unruh wrote:
>> mikel at irontec.com (Mikel Jimenez) writes:
>> And you are using ntpdate why? Why not set up ntp on the system and use it
>> to discipline your system's clock. Note whether you will get 1/100 sec
>> accuracy depends on the network etc.
> Although it isn't particularly clear, I believe he is running ntpdate on
> a machine that is properly synchronised, to measure the offsets of the
> Of course, the error in the cameras may well be an order of magnitude
> better than the offsets measured, either that way, or the more approved
> way of using configuring the cameras as ignored servers on the
> synchronizing machine.
> However, my gut feeling is that this application required that it be an
> explicit requirement to buy the cameras that they maintain an offset
> less than 10ms. If that was the case, then he should be pursuing this
> with the vendors of the cameras. If not, he should put it down to
> It seems unlikely to me that the cameras are runing NTP, rather than a
> basic implementation of SNTP, and even if they are running NTP, it is
> unlikely that they have included any of the recent optimisations for
> fast convergence, so he should be waiting several hours, after powering
> up the cameras, before doing anything critical.
> It's also worth noting that one really needs a local radio reference
> clock (although I suspect he's actually using the local clock as
> reference) to guarantee 10ms accuracy on the server. It is possible to
> get this most of the time with an internet time reference, but some care
> is needed to achieve it all the time.
>> And why are you comparing the offset?
> He wants the video feeds from the cameras to have their RTP timestamps
> within 20ms (probably he meant 10ms) of each other. I'm not sure why,
> as it would seem easier to retime outside of the camera. I'm guessing
> the RTP bit.
> questions mailing list
> questions at lists.ntp.org
How can I configure the server to cameras get server time every very
very short time? My objective is to get the server and 4 cameras
syncronizhed, not more 0.01s desyncronizhed, taking reference the server.
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