I actually have made that (running FreeBSD/NanoBSD), but it still costs $300-$400 or so -- seems like too much for a hobby when just running ntpd on some linux box you already have is almost as good. Maybe for people who have a static IP but no server running 24/7? Seems like a small group...
A small computer with the appropriate serial port (Soekris box, for example - $200 - $250 with power supply and small compact flash) plus Garmin 18lvc with the appropriate cabling (~$100). Then you still also need an (extra?) static IP address and space near a window (as you said). Doesn't seem like a big market!
Maybe I'll do that in the future if we setup a separate DNS name for SNTP clients. For "ntpd" it's not currently practical. The ntpd developers are working on some new features that might make occasionally changing IPs work better with it, but it'll be a long time before they're widely deployed.
Being able to leave, as you did, is part of the point of the pool system. With the static lists of DNS names and IPs, there wasn't a good way to stop providing service again.
It is frustrating with the abusers, but getting that fixed is a parallel problem to providing service. With the pool at least we can spread the abuse out over thousands of servers rather than having a handful of hardcoded servers getting all of it.
As others pointed out, NIST operates a set of high quality clocks available via NTP, too. Last I talked to someone there and tried to estimate the pool.ntp.org usage the two systems got a comparable number of requests.
There are different tradeoffs to using NISTs servers and using pool.ntp.org.
A long cable.:-) Depending on the equipment you can have cables several hundred feet long.
An (expensive) way is to use a CDMA receiver. The CDMA protocol needs accurate timing, so it's included in those signals. It's not as accurate as GPS, but it can work in places with no "sky view" access.
Yes, if a USB receiver makes it accurate enough for the monitoring system then it's fine. (Though the monitoring system has been tuned to be stricter and stricter over the years).
However: if the USB receiver has more "jitter" than the other internet servers you'd be syncing from as backup, then there's not much point in having it.
"My concer [sic] is that pool.ntp.com servers are not policed for accuracy."
But they are monitored and "policed". Stop spreading FUD.
In the last three months (the period where I have detailed data) we've had 4 servers off by more than a second while active in the pool. One of them (only active in the Ukraine and Europe) 4 times, the others just once.
I did the same query for "more than half a second" and got a few more servers, but still less than you can count on two hands.
We take a Really Long View. This isn't a short term "this would be fun, let's just try it" kind of project.
Yes, the traffic has been growing faster than the number of servers in the last ~9 months, so at the current rate it's Just Not Going To Work. We continuously need With all the people who've joined in the last ~20 hours we're in better shape, again.:-)
If you find any servers in the pool that are giving you bad time, please let me know.
In the NTP Pool system I have millions of measurements from just the last month. We take a server out of the pool pretty fast if it's not giving good time.
Actually... The USB latency can be pretty bad, so it's likely you'd get better time from a well-picked internet time server. You'd definitely get MUCH better time with a proper PPS (Pulse Per Second) time keeping GPS receiver or variations of that.
Yes - it'd be great if more ISPs offered time keeping services.
One of the plans for the pool is to let ISPs sign up their address space and tell where their NTP servers are. Then when a user using the pool asks for time servers we can point them to the local servers (if they are keeping proper time, etc etc). But it's a bit down the todo list, mostly due to lack of interests from ISPs.
The NTP Pool monitors the servers and only uses those with accurate time. A server drifting several seconds off would be taken out of the pool until it got fixed.
Also, the NTP daemons are Quite Good at ignoring the servers with Bad Time Keeping.
Using ntpd with the pool servers will give you much much much more accurate time than trying to set it manually after looking at a web page.
The NTP protocol gives very limited ways of limiting it, so short of just closing down if we can't add servers as fast as traffic is added, no - there isn't much we can do.
The vendor program is one way we're trying to get more control, but all else being equal - more servers helps.
One of the servers I've had in the pool for a long time (so it has accumulated lots of clients) is typically using ~3MB memory and 0.0% or 0.1% CPU on a dual 800MHz box.
I run the site listed as the mirror. We are not seeing more than ~15-25Mbit http traffic... ZzZZzz... Increasing now as the west coast is waking up though.:-)
- ask
Re:What Lessig Doesn't Point Out.
on
Lessig @ OSCON
·
· Score: 1
Yes, you are being unfair to Lessig. How changes in technology (plus the DMCA) affects the copyright was one of his main points! Go see it again!:-)
CD quality, burns them to the CD-R, downloads the cover art and lyrics and sends them to the color laser printer. It could possibly even schedule a micropayment to the artist's account and put a shortcut on John Q. Public's desktop in case he decides the album was worth it.
Who in their right mind would bother to buy a CD then?!
uh, in what you described you just did, actually! You paid the artist, did you not?:-)
And before you play that argument, you should read what Janis Ian has to say. (Selling cd's and performing music is what pays her bills).
Who is stealing now?
- ask
Re:A little off target though...
on
Lessig @ OSCON
·
· Score: 1
Without copyright, if I write a cool app and want to sell it, I'd only sell it once before anyone who wanted it could just get it for free...
A copyright term of *95* years instead of say 50 or even 14 years is not going to make you sell more software. What software did you use 14 years ago?
- ask
Re:Another unemployed Flash designer accounted for
on
Lessig @ OSCON
·
· Score: 1
I was talking about the size of the swf file; it's 8MB!
Almost all of that is the 32kbps mp3 file... it's more than 30 minutes, remember.
Slashdot Mirror
Depending on how you count "the NTP Pool" is either just me or it's all of us, hint hint. :-)
I actually have made that (running FreeBSD/NanoBSD), but it still costs $300-$400 or so -- seems like too much for a hobby when just running ntpd on some linux box you already have is almost as good. Maybe for people who have a static IP but no server running 24/7? Seems like a small group...
A small computer with the appropriate serial port (Soekris box, for example - $200 - $250 with power supply and small compact flash) plus Garmin 18lvc with the appropriate cabling (~$100). Then you still also need an (extra?) static IP address and space near a window (as you said). Doesn't seem like a big market!
Maybe I'll do that in the future if we setup a separate DNS name for SNTP clients. For "ntpd" it's not currently practical. The ntpd developers are working on some new features that might make occasionally changing IPs work better with it, but it'll be a long time before they're widely deployed.
Being able to leave, as you did, is part of the point of the pool system. With the static lists of DNS names and IPs, there wasn't a good way to stop providing service again.
It is frustrating with the abusers, but getting that fixed is a parallel problem to providing service. With the pool at least we can spread the abuse out over thousands of servers rather than having a handful of hardcoded servers getting all of it.
Ask
As others pointed out, NIST operates a set of high quality clocks available via NTP, too. Last I talked to someone there and tried to estimate the pool.ntp.org usage the two systems got a comparable number of requests.
There are different tradeoffs to using NISTs servers and using pool.ntp.org.
A long cable. :-) Depending on the equipment you can have cables several hundred feet long.
An (expensive) way is to use a CDMA receiver. The CDMA protocol needs accurate timing, so it's included in those signals. It's not as accurate as GPS, but it can work in places with no "sky view" access.
Yes, if a USB receiver makes it accurate enough for the monitoring system then it's fine. (Though the monitoring system has been tuned to be stricter and stricter over the years).
However: if the USB receiver has more "jitter" than the other internet servers you'd be syncing from as backup, then there's not much point in having it.
"My concer [sic] is that pool.ntp.com servers are not policed for accuracy."
But they are monitored and "policed". Stop spreading FUD.
In the last three months (the period where I have detailed data) we've had 4 servers off by more than a second while active in the pool. One of them (only active in the Ukraine and Europe) 4 times, the others just once.
I did the same query for "more than half a second" and got a few more servers, but still less than you can count on two hands.
- ask
We take a Really Long View. This isn't a short term "this would be fun, let's just try it" kind of project.
:-)
Yes, the traffic has been growing faster than the number of servers in the last ~9 months, so at the current rate it's Just Not Going To Work. We continuously need With all the people who've joined in the last ~20 hours we're in better shape, again.
Mr Anonymous,
If you find any servers in the pool that are giving you bad time, please let me know.
In the NTP Pool system I have millions of measurements from just the last month. We take a server out of the pool pretty fast if it's not giving good time.
- ask
Three of those servers are in agreement with each other on time within 3 milliseconds. Yes, that's a lot less than 0.1 seconds.
- ask
Yeah - the criteria really for "useful for the pool" is "doesn't change more than every few years".
The virtualized servers don't usually keep their own time - or when they do they do a poor job.
Actually ... The USB latency can be pretty bad, so it's likely you'd get better time from a well-picked internet time server. You'd definitely get MUCH better time with a proper PPS (Pulse Per Second) time keeping GPS receiver or variations of that.
Hi Nuintari,
Yes - it'd be great if more ISPs offered time keeping services.
One of the plans for the pool is to let ISPs sign up their address space and tell where their NTP servers are. Then when a user using the pool asks for time servers we can point them to the local servers (if they are keeping proper time, etc etc). But it's a bit down the todo list, mostly due to lack of interests from ISPs.
- ask
Hi AC,
The NTP Pool monitors the servers and only uses those with accurate time. A server drifting several seconds off would be taken out of the pool until it got fixed.
Also, the NTP daemons are Quite Good at ignoring the servers with Bad Time Keeping.
Using ntpd with the pool servers will give you much much much more accurate time than trying to set it manually after looking at a web page.
- ask
The NTP protocol gives very limited ways of limiting it, so short of just closing down if we can't add servers as fast as traffic is added, no - there isn't much we can do.
The vendor program is one way we're trying to get more control, but all else being equal - more servers helps.
I must mention that right now by signing up for the pool now you also have a chance to get some really cool time keeping equipment. :-)
ntpd uses almost no CPU at all.
One of the servers I've had in the pool for a long time (so it has accumulated lots of clients) is typically using ~3MB memory and 0.0% or 0.1% CPU on a dual 800MHz box.
- ask
Actually, developing Parrot in parallel with Perl 6 is speeding up development!
- ask
I run the site listed as the mirror. We are not seeing more than ~15-25Mbit http traffic... ZzZZzz... Increasing now as the west coast is waking up though. :-)
- ask
Yes, you are being unfair to Lessig. How changes in technology (plus the DMCA) affects the copyright was one of his main points! Go see it again! :-)
:-)
CD quality, burns them to the CD-R, downloads the cover art and lyrics and sends them to the color laser printer. It could possibly even schedule a micropayment to the artist's account and put a shortcut on John Q. Public's desktop in case he decides the album was worth it.
Who in their right mind would bother to buy a CD then?!
uh, in what you described you just did, actually! You paid the artist, did you not?
And before you play that argument, you should read what Janis Ian has to say. (Selling cd's and performing music is what pays her bills).
Who is stealing now?
- ask
Without copyright, if I write a cool app and want to sell it, I'd only sell it once before anyone who wanted it could just get it for free...
A copyright term of *95* years instead of say 50 or even 14 years is not going to make you sell more software. What software did you use 14 years ago?
- ask
I was talking about the size of the swf file; it's 8MB!
Almost all of that is the 32kbps mp3 file... it's more than 30 minutes, remember.
- ask
- ask (cvs.perl.org maintainer).