NTP Service
One of the most important time synchronization services we
provided for the populace is the Network Time Synchronization
Service. The Network Time Synchronization Service uses Network
Time Protocol (NTP) to synchronize clocks of computers in the
Internet with national standard time. NTP builds a time
tracking system in a hierarchical structure. The NTP timeserver
with lower hierarchy is synchronized to that with higher one.
NTP can estimate the network propagation delay and compensate
the effect of delay for adjusting the local computer clock.
In the Internet, the accuracy of NTP is about a few tens of
milliseconds. Thus, it can provide an accurate time source
for most information applications, including the Time Stamp
Authority (TSA) application.
We have begun to provide the Network Time Synchronization
Service since June 1998. We installed multiple NTP timeservers
in our Lab. and developed a friendly client program implementing
Simple Network Time Protocol (SNTP) for Windows OS
environments, such as Windows 95/98/NT. In addition, we
also designed a system to monitor our NTP services and
the monitoring program is used to count the number of
NTP access to our NTP timeservers. Up to October 2000,
the number of NTP requests is more than two million
(2,000,000) connections a day. NTP provides an authentication
option to implement the security function. However, the
present version client program does not implement any
authentication function. To design a powerful authentication
mechanism for our NTP system would be the future work.
