[ntp:questions] Accuracy of audio tones via VOIP

Harlan Stenn stenn at ntp.org
Tue Jul 9 22:20:18 UTC 2013

The telephone system used to be a very good way to get the time, back
when there were real hardware modems (constant delay) as opposed to
software modems (which do not have constant delay) and when there was
actual copper wire all the way between your wall jack and NIST.  Now
that phone signals are digitally transmitted, the quality of "time
transmission" over the phone lines are further degraded.

Not sure how much - it would be interesting to collect the data.


More information about the questions mailing list