Development of a High-Accurate Time Server for Measurements of the Internet

The network delay is one of the essential elements h)r the Quality of Service (QoS). The time delay is measured by placing devices at both ends of the network and using the machine's internal time clock. The accuracy of the measurement is dependent on the precision of tihe clock, therefore the precision of the clock is very important. Network Time Protocol (NTP) is applied for the time synchronization amnong network nodes; hence, the time accuracy at each NTP server is considered very importmLt. Moreover, the improvement of the accuracy is required for the recent, broadband network.Our objective in this research is to improve the time stability of the top NTP server (stratum1) by developing a server with higher stability. The server, which is called the high-accurate time server, was designed based on external high accurate frequency signal, insted of the crystal oscillator on the motherboard of a Personal Computer (PC). The high-accurate time server is capable of the time stability of several hundred nanoseconds. Also evaluated in this paper is the high precision measurement of network delay, which was proceeded with the server.