Time Services The heartbeat of any network backbone is accurate time services. ESnet provides authenticated time services, synchronized using WWVB and GPS time sources. NTP (Network Time Protocol) is the protocol used for synchronizing the clocks on multiple hosts on the Internet. NTP allows for multiple clock "sources" for redundancy, and performs sanity checks across these sources to ensure that the local host's time is accurate. These servers obtain their time from locally connected radio clocks, which in turn source their time from the WWVB broadcast out of Fort Collins, Colorado. Additionally, ESnet time is synchronized using GPS (Global Positioning System) satellites, which constantly circle the globe transmitting time synchronization signals.