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

[bmanning () karoshi com]

> > 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

--bill