Robert E. Seastrom wrote:
Actually, you're looking for two different things here:
1) a frequency standard that is traceable to a cesium or rubidium frequency source, with an output of 1 MHz, 10 MHz, 100 MHz, or whatever the PLL in the Cisco wants to see to discipline the line clocking, and
2) a time standard (synchronized to USNO) with a 1PPS output that is synchronized to the top of the second.
We're using (as a stratum 1 NTP clock) the Datum Inc. TymServe 2100 box, a nice 1U rack-mount unit which receives GPS and outputs NTP and 1PPS (satisfying 2 above) and also has a 10MHz output (satisfying 1 above). A rubidium oscillator is an option on this box. See http://www/datum.com/ for more details. Disclaimer: No affiliation to Datum Inc... just a customer! James