The Sonoma N12 is a Stratum 1 NTP server that provides an accurate, reliable and secure source of network time inside your firewall. Most Stratum 1 NTP servers require an antenna that must be installed on the roof of your building, with good sky visibility. The Sonoma eliminates this problem by synchronizing to signals broadcast from the CDMA mobile cellular/PCS telephone system. You can install the antenna wherever the unit is located, even on top of your equipment rack, and still have an NTP server that is as stable and accurate as with GPS. And, by installing the antenna safely inside, the Sonoma eliminates any risk of damage to your equipment rack caused by lightning strikes.