New on RIPE Labs: NTP Measurements with RIPE Atlas
Dear colleagues, This new RIPE Labs article describes how RIPE Atlas probes and anchors maintain their clocks, and how accurate these clocks are. We also plan to make the NTP measurements we describe here available as an additional measurement type for RIPE Atlas users: https://labs.ripe.net/Members/philip_homburg/ntp-measurements-with-ripe-atla... Kind regards, Mirjam Kuehne RIPE NCC
Hi, On Tue, Feb 17, 2015 at 03:34:40PM +0100, Mirjam Kuehne wrote:
This new RIPE Labs article describes how RIPE Atlas probes and anchors maintain their clocks, and how accurate these clocks are. We also plan to make the NTP measurements we describe here available as an additional measurement type for RIPE Atlas users:
Oh the irony :-) my atlas anchor is sitting quite close to what used to be TT12 and TT155, and both still provide Stratum-1 NTP to anyone who asks... Gert -- have you enabled IPv6 on something today...? SpaceNet AG Vorstand: Sebastian v. Bomhard Joseph-Dollinger-Bogen 14 Aufsichtsratsvors.: A. Grundner-Culemann D-80807 Muenchen HRB: 136055 (AG Muenchen) Tel: +49 (0)89/32356-444 USt-IdNr.: DE813185279
Oh the irony :-) my atlas anchor is sitting quite close to what used to be TT12 and TT155, and both still provide Stratum-1 NTP to anyone who asks...
if you are suggesting that the atlas anchor or atlas probes would do better resolution if they chimed off that strat-1, i am not so sure. i suspect the issues are internal to the actual probe/anchor. at C, a packet can get to the moon and back in a bit over two seconds. randy
Hi, On Thu, Feb 19, 2015 at 05:44:28PM +0900, Randy Bush wrote:
Oh the irony :-) my atlas anchor is sitting quite close to what used to be TT12 and TT155, and both still provide Stratum-1 NTP to anyone who asks...
if you are suggesting that the atlas anchor or atlas probes would do better resolution if they chimed off that strat-1, i am not so sure. i suspect the issues are internal to the actual probe/anchor.
No, that was more like "Atlas replaces TTM, which had nice built-in Stratum-1 clocks, and look, my Atlas Anchor could happily use those leftovers from TTM to get great time!" - I found it amusing. Seriously, with the measurements Atlas does, I expect precisely synchronized time between nodes to be much less relevant than for TTM - for one-way measurements, it needs to be as precise as you can get, for "send a packet and wait until the answer comes", having something in the 0.1 second precision range strikes me as "good enough to find the measurement in question in the log". Gert Doering -- NetMaster -- have you enabled IPv6 on something today...? SpaceNet AG Vorstand: Sebastian v. Bomhard Joseph-Dollinger-Bogen 14 Aufsichtsratsvors.: A. Grundner-Culemann D-80807 Muenchen HRB: 136055 (AG Muenchen) Tel: +49 (0)89/32356-444 USt-IdNr.: DE813185279
participants (3)
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Gert Doering -
Mirjam Kuehne -
Randy Bush