Re: NTP Sync Issue Across Tata (Europe)

[Seth Mattinen via NANOG <nanog () nanog org>]

On 8/9/23 2:39 AM, Forrest Christian (List Account) wrote:
> When GPS is working, time transmission with accuracies of under 1 
> microsecond is common.   This is especially true if the GPS integrates 
> some sort of disciplined oscillator.  Note that this is in excess of 
> what NTPd running on a typical OS can reliably retransmit.
>
> BUT..  if I was to choose only one protocol, it would be NTP, not GPS, 
> because of all of the reasons you mention.
>
> I find it distressing that sites are relying on GPS only.  I suspect 
> that this a failure to assign proper risk to using GPS.  It's 
> particularly odd when one considers that adding NTP time sources are 
> essentially free and improve robustness and reliability greatly.


I liked having a WWVB receiver in my mix, but all the hardware 
appliances (at least those offering OCXO or Rubidium oscillator options) 
seem to have rejected it in favor of GPS only. I can only conclude that 
either vendors think options like WWVB are a dead end or there's no 
demand for GPS alternatives.

Products like the BlueSky GNSS Firewall exist, but not something I've 
thought was as necessary expenditure for my needs (yet). Mouser lists it 
at just under $10k.

Personally I'm just not that comfortable using random unknown platform 
and unknown installation conditions time server pools over the big-I 
internet. I would possibly consider NTP servers operated by entities I 
have peering with.

~Seth