Re: NTp sources that work in a datacenter (was Re: Is latency equivalent

[Peter Lothberg <roll () stupi se>]

The receiver do not need to be in the datacenter, there is this thing
called "the internet" that you can hook it up to.

> > > in every PoP to do measurements. In that case, the difficulty isn't in 
> > > measuring one-way latency, it's in synchronizing the time on all the 
> > > servers. And with fairly cheap GPS and CDMA clocks that is a lot 
> > > easier/cheaper than it once was.
>
>       a robust mesh of strat-2 chimers gives one more resilence
>       and more accuracy than syncing off a single source.
>
> > But what GPS clock can you install in a datacenter? AFAIK, they all 
> > require roof (or at least window) access in order to install the 
> > antenna. (At least, all the GPS based ntp servers I've looked at do).
> > Is that not true of CDMA servers?
>
>       some GPS, some PPS, and an atomic source here and there 
>       give great diversity and only a few need roof access.
>       
> > How have others solved this issue? (Short of owning their datacenters.)
>
>       Use NTP, run most systems as strat-2

Time2.Stupi.SE and Time4.Stupi.SE are both stratum-1 accessable through
the Internet, tracable to UTC-SP (part of TAI) without use of GPS or slaving
to CDMA (that slaves to GPS). 

-P