Super Accurate clock for your PC

I thought I remembered reading years ago that the exact path of data on the web was almost random and if the same data was sent again, it probabily would take a different path (longer/shorter), is this true?? (I'm no telecoms expert)....

You really dont want to start me answering questions about network routing algorithms

The exact path may change due to machines sharing the workload, and trying to find optimal routes at different times of the day. However in general the path taken will be fairly similar. If a main hub has a power failure or something then the routes will reconfigure a different way, but in general the paths are similar.

For example I've been tracing the route my machine is using to mit.edu for the last 15 minutes or so and there has only been one slight change in the route:
[code:1]$ tracert life.ai.mit.edu

Tracing route to life.ai.mit.edu [128.52.32.80]
over a maximum of 30 hops:

1 7 ms 2 ms 2 ms 192.168.1.100
2 * 24 ms 26 ms bas502.cwt.esat.net [193.95.136.238]
3 31 ms 24 ms 26 ms vlan501.rt502.cwt.esat.net [193.95.137.125]
4 25 ms 27 ms 24 ms vlan52.rt001.cwt.esat.net [193.95.130.145]
5 26 ms 29 ms 28 ms ge3-0.br003.cwt.esat.net [193.95.129.6]
6 44 ms 38 ms 40 ms so-4-0-0.ar1.dub1.gblx.net [208.48.24.217]
7 61 ms 56 ms 56 ms so1-0-0-2488M.ar1.AMS1.gblx.net [67.17.65.242]
8 64 ms 59 ms 60 ms ge-7-2.core1.Amsterdam1.Level3.net [213.244.165.237]
9 57 ms 57 ms 57 ms ae-0-51.mp1.amsterdam1.level3.net [213.244.165.1]
10 58 ms 60 ms 59 ms so-0-0-0.bbr2.London1.Level3.net [212.187.128.25]
11 123 ms 122 ms 124 ms as-0-0.bbr1.newyork1.level3.net [4.68.128.106]
12 132 ms 127 ms 126 ms as-2-0.mp2.boston1.level3.net [64.159.4.181]
13 132 ms 126 ms 129 ms ge-10-0.hsa2.Boston1.Level3.net [4.68.100.5]
14 133 ms 128 ms 125 ms 4.79.2.2
15 135 ms 128 ms 129 ms B24-RTR-2-BACKBONE.MIT.EDU [18.168.0.23]
16 137 ms 126 ms 133 ms MITNET.TRANTOR.CSAIL.MIT.EDU [18.4.7.65]
17 137 ms 135 ms 134 ms trantor.kalgan.csail.mit.edu [128.30.0.246]
18 133 ms 130 ms 128 ms life.ai.mit.edu [128.52.32.80]

Trace complete.
[/code:1]
One time it took a diversion [code:1] 11 127 ms 123 ms 121 ms as-0-0.bbr1.newyork1.level3.net [4.68.128.106]
12 129 ms 128 ms 130 ms so-0-1-0.mp1.boston1.level3.net [209.247.9.125]
13 127 ms 128 ms 128 ms ge-10-2.hsa2.boston1.level3.net [4.68.100.133]
14 132 ms 128 ms 131 ms 4.79.2.2
[/code:1]

But thats probably just load balancing in Boston, the machines are quite possibly in the same room, this type of change would be fairly common. The packets all took the same basic route though. Me -> esat -> Dublin -> Amsterdam -> London -> New York -> Boston -> AI lab in MIT.

So back to your comment. I dont think that its probable that the packets would take a differnt path, but it is possible.

Cheers,
~Al

If you need to be sure you can view a live java based internet clock at www.nist.time.gov , chances are if your system time is the same as the clock on this website you've been pretty successful synchronizing time.

You really aren't gonna get better time on your PC than NTP will give you. It is called the Network Time Protocol because it was designed from the ground up to work on real world networks. It is designed around things like network latency and possible routing and takes all these things into account. To use itcorrectly it should also be set to use as many peers and servers as possible, that way you will get the absolute best time.

I use it on servers and generally have three peers (machines at your level) and one or two servers higher up the chain (closer to the atomic clocks).

NTP will be better than any applet on the web, it is as good as you are gonna get really!

Personally I just needed some assurance- I have my laptop sitting beside my desktop- I use Symm time on my desktop and the built in XP NTP feature, but they were both giving different times- out by about 8 seconds. When I launched the Applett I got the exact same time on each machine. The Symm time program exactly matched the Applett, so I figure the Windows feature is just plain useless.

Of course, all you folks with GPS telescopes don't need to worry about such things)))

Of course, all you folks with GPS telescopes don't need to worry about such things)))

GPS will be out a tad too - best I've gotten is within a 16 foot radius.

I was given a cheap clock that uses a radio signal transmited from an atomic clock somewhere and I assume it is fairly precise or at least out by the amount of time the radio signal takes to get to me.

Doesn't the GPS take the time from the satellites? As far as I know GPS time is accurate to within one millionth of a second, better than any NTP server!