Re: [time-nuts] can of worms: time-of-day in a community radio station

stevesommars...@gmail.com said: > If the bad guys can intercept NTP traffic timestamps can be altered, unless > NTP authentication is used. [This rarely happens.] For those not familiar with this area... There are 2 ways to authenticate NTP packets. You can setup a shared key. This

Re: [time-nuts] can of worms: time-of-day in a community radio station

> This is a pretty baseless fear. The servers in the ntp pool > are constantly monitored and those that are off by more than 100ms > are quickly removed (within 2-3 hours, IIRC). In computer security it's a big no-no to use unknown or untrusted sources of information, as simple as that. A random

Re: [time-nuts] can of worms: time-of-day in a community radio station

Each NTP Pool server's real-time status can be seen at https://www.ntppool.org/scores/*ip_address* I can't answer questions about the monitor's source code NTP server timestamp errors happen occasionally. Internet delays and losses are unpredictable. My

Re: [time-nuts] can of worms: time-of-day in a community radio station

Hi Since “rogue” servers are rare, bumping up the number of servers fairly quickly gets you to a very high degree of confidence. Is that 5, 7, 9, or 11? It sounds like a wonderful topic for somebody’s thesis or dissertation :) Given that this is a free resource and that the network usage is

Re: [time-nuts] can of worms: time-of-day in a community radio station

att...@kinali.ch said: > This is a pretty baseless fear. The servers in the ntp pool are constantly > monitored and those that are off by more than 100ms are quickly removed > (within 2-3 hours, IIRC). Of course, if you are already using one of those, > then the removal will not help you. But

Re: [time-nuts] can of worms: time-of-day in a community radio station

On Sat, 19 Oct 2019 18:24:57 -0700 Fiorenzo Cattaneo wrote: > The main reason I do not trust "pool" servers is because there is no > guarantee of which server you will get. I might be paranoid, but I am > worried about rogue servers, and I much rather trust well known public > stratum-1 NTP

Re: [time-nuts] can of worms: time-of-day in a community radio station

Achim, thank you for your graph and for the link to Dan Drown blog and your suggestions. I am going to collect data and replicate his research. I doubt I'll discover anything new, but it's interesting nevertheless to look into these time series data. -- Fio Cattaneo Universal AC, can Entropy be

Re: [time-nuts] can of worms: time-of-day in a community radio station

> My understanding is that it would work moderately well even without a > stratum-1 server, at least be able to operate within a few tens of > milliseconds for several hours. Although I confess I haven't used peering in > a very long time. In my workplace we added stratum-1 GPS symmetricom NTP >

Re: [time-nuts] can of worms: time-of-day in a community radio station

> > > With this setup you have no single point of failure, and even if the > > connection to internet fails, they can still provide time as they are > > peering > > and synchronizing with each other. > No, it doesn't work that way. You need connectivity to at least one stratum 1 > server. >

Re: [time-nuts] can of worms: time-of-day in a community radio station

Fiorenzo Cattaneo writes: > I have been quite puzzled about the asymmetric nature of my home Cable > Modem connection to the Internet in regard with the offset discrepancy > I observe. The "last mile" asymmetric nature of Cable Modem (Comcast > in my case) is not very high compared the delta I see

Re: [time-nuts] can of worms: time-of-day in a community radio station

Hi. Personally, I would not trust an "ISP" based NTP server!  From personal experience, they tend to run them on the heavily congested border/gateway systems.   As you can find and confirm using the usual network routing and diagnostic tools. As has been said, local GPS / Internet sync'd servers

Re: [time-nuts] can of worms: time-of-day in a community radio station

I scanned the NTP pool last leap second and relayed the list of offenders to Ask. NTP pool servers may use a mixture of smeared and non-smeared upstream servers. Yuck. While the NTP pool has limitations it is widely used (and abused). NTP servers outside of the NTP pool may also be imperfect.

Re: [time-nuts] can of worms: time-of-day in a community radio station

> You can't test a server for smearieness. It wouldn't surprise me if some of > them turn out to be getting time from google servers or something similar. True, but you *can* see which upstream time source has been selected for a NTP server. Ask went through the pool servers last leap-second and

Re: [time-nuts] can of worms: time-of-day in a community radio station

Regarding analog clocks, what is the groups opinion on these Atomic WWVB Signal Radio Controlled Clock Movements? I ordered one from China but it isn't here yet. I am hoping that I won't have to change the clock for DST. They are only $15. https://www.klockit.com

Re: [time-nuts] can of worms: time-of-day in a community radio station

You can't test a server for smearieness. It wouldn't surprise me if some of them turn out to be getting time from google servers or something similar. The last time I checked over 50 of the NTP pool stratum 2 servers used Google, based on the Reference ID. The NTP pool folks are aware of the

Re: [time-nuts] can of worms: time-of-day in a community radio station

Hi Once you dig into all the sources of delay, the asymmetry is much more likely to be dimensioned in miliseconds than in microseconds. There are a lot of things that contribute to the total. Bob > On Oct 20, 2019, at 7:31 PM, Hal Murray wrote: > > > f...@cattaneo.us said: >> Maybe I

Re: [time-nuts] can of worms: time-of-day in a community radio station

themadbea...@gmail.com said: > In reference to using the NTP Pool, someone mentioned they don't trust them > and the possibility of a "rogue" server. The NTP Pool has a monitor that is > constantly querying every server in the pool, if the time drifts too far it > is removed from the DNS

Re: [time-nuts] can of worms: time-of-day in a community radio station

f...@cattaneo.us said: > Maybe I should double check the routing from both ends again and make sure > they are really symmetric.. I can also ask my coworkers in the networking > group and hear what they think about it. We need a cable TV geek. It wouldn't surprise me if the upstream

Re: [time-nuts] can of worms: time-of-day in a community radio station

I have been quite puzzled about the asymmetric nature of my home Cable Modem connection to the Internet in regard with the offset discrepancy I observe. The "last mile" asymmetric nature of Cable Modem (Comcast in my case) is not very high compared the delta I see between my stratum-1 servers at

Re: [time-nuts] can of worms: time-of-day in a community radio station

Eric, As many others have mentioned, Meinberg has an excellent Windows port of NTPD that replaces the (horrible) default SNTP client. Linux & Mac should both have the standard NTPD distributions available. Since you mentioned internet outages (without mentioning frequency or duration), adding in

Re: [time-nuts] can of worms: time-of-day in a community radio station

Replies to several messages collected here to reduce traffic. artgod...@gmail.com said: > Off-the-wall thought : could you discipline a well-insulated raspberry pi > to NTP using heaters or workload to modify its temperature ? Yes. https://blog.ntpsec.org/2017/03/21/More_Heat.html The

Re: [time-nuts] can of worms: time-of-day in a community radio station

I'd definitely think so, good idea :-) . I've also seen some open source projects which calibrate the PPM drift based on the measured temperature either using the CPU's temperature measurement or a cheap USB temperature ambient sensor, thus implementing some sort of "software ovenization".

Re: [time-nuts] can of worms: time-of-day in a community radio station

Hello David, >>> I'm surprised you don't trust "pool" servers. My experience is that using >>> the pool directive, and allowing NTP to expand its server list automatically >>> to the maximum number of servers, gives good results usually with one of two >>> servers at least being stratum-1

Re: [time-nuts] can of worms: time-of-day in a community radio station

On 10/18/19 12:20 PM, Eric Scace wrote: I fear that I am developing a reputation for bringing to the list rather oddball questions. In my rôle as agent provocateur, therefore, here is another such problem. Questions for you are at the end. Thanks for your thoughts,. — Eric I

Re: [time-nuts] can of worms: time-of-day in a community radio station

Adrian Godwin writes: > Off-the-wall thought : could you discipline a well-insulated raspberry pi > to NTP using heaters or workload to modify its temperature ? Yes you can, been doing that with four rasPi and two TinkerBoards for quite a while now to run the XTAL at its turnover temperature

Re: [time-nuts] can of worms: time-of-day in a community radio station

"Of course this is why I am a time-nut :-)" I might say you graduated from the Advanced class with honors :) Didier KO4BB ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to

Re: [time-nuts] can of worms: time-of-day in a community radio station

Hi There is the “good old way” to keep the station clocks running right in a non-profit radio station: At some odd hour of the day, one day a week, the tech geek fires up WWVB and pipes it into an audio trunk. He / she then wanders around with a set of headphones. Each clock in the station gets

Re: [time-nuts] can of worms: time-of-day in a community radio station

On Sat, Oct 19, 2019 at 4:17 AM Hal Murray wrote: > > The crystal is a thermometer. On modern systems, the temperature depends > on > the workload as well as the air conditioning. > > Off-the-wall thought : could you discipline a well-insulated raspberry pi to NTP using heaters or workload to

Re: [time-nuts] can of worms: time-of-day in a community radio station

Take a look at vClock https://voceware.co.uk/products-vclock.aspx You could run on a surplus PC with a reliable NTP client. I like Tardis as I can set the servers that it queries and set limits to the amount of correction it applies so that it can compensate for PC RTC drift without the risk

Re: [time-nuts] can of worms: time-of-day in a community radio station

Hi David, I don't particularly trust NTP servers from pool.ntp.org (I assume that is what you mean by "pool"), and I use public stratum-1 servers chosen from a public list. Of course I make sure that my usage complies with the policies and terms of use for each server (some allow regional use

Re: [time-nuts] can of worms: time-of-day in a community radio station

> With this setup you have no single point of failure, and even if the > connection to internet fails, they can still provide time as they are peering > and synchronizing with each other. No, it doesn't work that way. You need connectivity to at least one stratum 1 server. There is an

Re: [time-nuts] can of worms: time-of-day in a community radio station

Hi David, I don't particularly trust NTP servers from pool.ntp.org (I assume that is what you mean by "pool"), and I use public stratum-1 servers chosen from a public list. Of course I make sure that my usage complies with the policies and terms of use for each server (some allow regional use

Re: [time-nuts] can of worms: time-of-day in a community radio station

Here are (some) answers to your questions. Using NTP to synchronize time across all machines is the one which makes the most sense IMHO. In the past I setup the NTP server architecture for a "megacorp" I was working for, and I have replicated the same setup (at a much smaller case) in my house.

Re: [time-nuts] can of worms: time-of-day in a community radio station

I fear that I am developing a reputation for bringing to the list rather oddball questions. In my rôle as agent provocateur, therefore, here is another such problem. Questions for you are at the end. Thanks for your thoughts,. — Eric [] ===

Re: [time-nuts] can of worms: time-of-day in a community radio station

Just out of curiosity, how many PSc/laptops/servers does it take to run a radio station? e...@scace.org said: > What NTP software should be used on Windows OS machines? Linux servers? There is a version of ntpd available for Windows. Meinberg builds and distributes it. Most Linux distros

Re: [time-nuts] can of worms: time-of-day in a community radio station

Have no idea if they exist still but what you need is time of day clocks and what are called shot clocks. A shot clock is a clock thats preloaded with a segment duration and counts to zero. No thinking is the key. These have been used for years and years. That makes talents job very very easy.It

Re: [time-nuts] can of worms: time-of-day in a community radio station

Our makerspace is using a BSD licensed product called OAS (On Air Screen) in the studio, with a slave displays planned at the engineers workstation, and in the Makerspace workshop . Link: github.com/saschaludwig/OnAirScreen OAS has been set up on an Raspberry  PI, with the PoE shield on the

Re: [time-nuts] can of worms: time-of-day in a community radio station

I only have one idea.  Something I thought of doing it myself but have not done so, yet. I think syncing locations with GPS or ntp is good enough for time synchronization.  But display could be problematic.  As they make transition from one program to another, 1 second overlap or 1 second of

Re: [time-nuts] can of worms: time-of-day in a community radio station

use Meinberg ntp if running Windows systems. If you can you can drive an analog display derived from the system time all the better as humans can relate to that better than a digital clock display. Daviud -Original Message- From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On

Re: [time-nuts] can of worms: time-of-day in a community radio station

Hi A very normal internet based NTP setup will do what you wish to do. The main task is to make sure that your devices are *really* running NTP and not some odd thing built into their OS. The more devices / operating systems / OS versions / system configurations you have the more exciting

Re: [time-nuts] can of worms: time-of-day in a community radio station

Sadly the formatting of the original message was stripped by the email server. Here is a slightly more comprehensible version. On 2019 Oct 18, at 15:20 , Eric Scace wrote: I fear that I am developing a reputation for bringing to the list rather oddball questions. In my rôle as agent