In NTP terminology, a Stratum-1 time server is linked to UTC sources such as GPS via what medium?

• A. A direct USB connection
• B. A network path
• C. A local clock only
• D. External battery

Answer: (B)

In NTP, a Stratum-1 time server is directly synchronized to a UTC reference clock such as GPS. The key idea is that the time source is a UTC reference, and the server uses that reference to discipline its own clock. The medium through which that UTC time reaches the server and is then offered to clients is a network path. In practice, the GPS or other UTC source may connect to the server via a physical interface (like serial or USB), but the time information is propagated and served over the network. Therefore, the medium described in the context of delivering the UTC time to and from the server is a network path.