Date: Wed, 17 Sep 1997 06:31:55 +0200 (MET DST) From: Eivind Eklund <perhaps@yes.no> To: joerg_wunsch@uriah.heep.sax.de (Joerg Wunsch) Cc: hackers@FreeBSD.ORG Subject: Re: Kernel clock runs inaccurately Message-ID: <199709170431.GAA29657@bitbox.follo.net> In-Reply-To: j@uriah.heep.sax.de's message of Thu, 11 Sep 1997 06:42:31 %2B0200 References: <199709080124.JAA14004@tao.sinanet.com.tw> <19970908081010.DS04250@uriah.heep.sax.de> <199709102025.WAA02815@bitbox.follo.net> <19970911064231.JG62790@uriah.heep.sax.de>
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> > As Eivind Eklund wrote: > > > > (They are probably living in somewhat of an ivory tower with > > > good NTP refclocks readily available on a cheap Internet, something > > > that is not my situation, sitting behind dialup lines everywhere.) > > > > Shouldn't it be still be possible to set up xntpd with > > drift-correction and synchronization often, and just suppress > > xntpd-messages from starting the ppp-link? > > Too expensive still. The dialup itself is ISDN, so the setup time is > ~ 2 seconds or less, but having an xntpd calling each 5 or 15 minutes > would greatly increase our phone and Internet costs. I was suggesting _suppressing_ dial-out when xntpd tried to send a packet. Ie, something similar to the dial filter in IIJ-PPP, ignoring NTP-packets. No call every 15 minutes, just a synchronization when you're online for another reason. With a continuous connection, though, xntpd is supposed to lower the check-interval as it get more info on your clock-drift, ending up at once every 6 hours or so. The timing on an ISDN-link might not be stable enough for this to happen, though. BTW: What kind of setup are you running to get <2s setup time? I'm consistently ending up at 4-5s, having tried with different external TAs, ISDN-adapters, PPP-implementations and portmasters. Eivind.
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