CenturyLink

Sun Dec 30 11:58:19 UTC 2018

Actually, on all our trading systems, our times are synced via PTP instead of ntpd for at least 50 microsecond accuracy. The stratum 1 clocks as well as NIST time are only used as comparison to verify compliance and reality. We use ntpq to determine the offset  from NIST for reporting.

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Matthew Huff             | 1 Manhattanville Rd 
Director of Operations   | Purchase, NY 10577
OTA Management LLC       | Phone: 914-460-4039

-----Original Message-----
From: NANOG [mailto:nanog-bounces at nanog.org] On Behalf Of Stephen Satchell
Sent: Saturday, December 29, 2018 10:01 AM
To: nanog at nanog.org
Subject: Re: CenturyLink

On 12/29/18 6:51 AM, Matthew Huff wrote:
> We have two stratum-1 servers synced with GPS and a PTP feed from a provider that also provides PTP to market data systems, but we still have to monitor drift between system time and NIST time. Don't ask for the logic behind it, it's a regulation, not a technical requirement.

Having been a participant on Standards Working Groups, I understand completely.  Regulations, like Standards, need to be written to apply to as wide a population as possible.  Do those regulations dictate how you monitor drift?  For example, can you have a system (I would use CentOS) that syncs to the appliance as well as NIST and your inside NTP sources, and use ntpq(8) to read the drift directly?