On Mon, Jul 21, 2014 at 11:01:19PM -0700, Hal Murray wrote: > > I expect that there's date and time information being sent in the header of > > every phone call, maybe even before the first ring along with the Caller ID > > info.
> Wiki says CallerID is sent between the first and second ring, and includes > the date and time. > http://en.wikipedia.org/wiki/Caller_ID#Operation Some old modems will happily decode it for you. I compared it to NTP at some point last year. The time stamp was only given to the nearest minute, and for my exchange it was pretty terrible - it was slow by about 90s for a few months. I was considering adding it to my leap second measurements, but there didn't seem to be much point. David. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
