Survey of NTP surveys

The little I know about NTP surveys, in chronological order:

1989, Mills, [url]http://www.eecis.udel.edu/~mills/database/papers/ccr.ps[/url]

1994, James Guyton, I only know of this because it is referenced in
Minar below.

1997, Mills,
[url]http://www.eecis.udel.edu/~mills/database/papers/survey5.ps[/url]

1999, Nelson Minar,
[url]http://alumni.media.mit.edu/~nelson/research/ntp-survey99/[/url]

2005, Cristina Duarte Murta and Pedro R. Torres Junior,
[url]http://ntpsurvey.arauc.br/[/url]

Any other URL's I should know of?

Interesting numbers for time evolution of count of stratum-1's:

1994: 66
1997: 220
1999: 957
2005: 533

Minar (1999) reveals that vast majority (657 of the 957) of claimed
Stratum 1's that he counted are in fact LCL (not obviously tied to a
refclock). The decrease between 1999 and 2005 numbers may reflect not a
decrease in Stratum 1's that are locked, but in fact a decrease in
misconfigured NTP hosts. (Minar identifies a specific Red Hat
distribution responsible for many of the misconfigurations, and I
suspect that few of these are still alive.)

I would be most interested if the 2005 survey (which the authors say is
in the publication process) reveals some details about the stratum-1's
and their diversity of refclocks. At the time of Minar's 1999 survey
GPS was far and away most common, and I suspect that diversity of
refclocks has degraded even more since then.

Tim.

Tim,

not all Stratum 1 administrators allow "strangers" to do:

ntpdc -n -c sysinfo -c peers -c monlist

on thier machines.

So, I suspect the information about refclocks are not enough accurate
to make a conclusion. I have three Stratum 1 servers available to the
public ONLY for time synchronization.

[email]shoppa@trailing-edge.com[/email] writes:
[color=blue]
>Any other URL's I should know of?[/color]

Several people did various NTP observations around the leap second
at the end of 2005. I guess this has a different emphasis to a
general survey, but does represent measurements of the NTP network.
My observations of the leap second are recorded at:

[url]http://www.maths.tcd.ie/~dwmalone/time/leap2005.html[/url]

and include some NTP stuff. I also have some links to what other
people recorded, though the list is not exhaustive.

David.