Network
Time Service (NeTS)
NeTS (Network Time Service) is a service
that allows users to synchronize computer clocks via
the Internet. The transmitted time code from the NeTS
server is traceable to UTC(SG). NeTS server can response
to time request from clients in format of any of the
following protocols: Daytime Protocol,
Time Protocol and Network Time
Protocol (NTP). The three major timing protocols
are defined in a series of RFC (Request For Comments)
documents. Our NeTS server is a stratum-1 time server,
located in the timing laboratory of National Metrology
Centre. Its registered domain name
is nets.org.sg. To access NeTS server, you need a client
software which can be found from the table below. However,
if you use other client software, you can choose or
add nets.org.sg as your time server.
Download Network Computer
Time Service (NeTS) Software
The Time Protocol specified in RFC-868
uses udp/ip port 37, it provides a site-independent,
machine readable date and time. It is the simplest one
among the three protocols. The time service sends back
to client the time in unformatted 32-bit binary code
containing time in UTC seconds since midnight on January
first 1900. The server should either refuse the connection
or close it without sendng anything if it is unable
to determine the time at its site. This protocol may
be used either above TCP or above UDP.
The Daytime Protocol specified in
RFC-867 uses tcp/ip port 13. Once a connection is established,
the server simply sends the current date and time as
an ASCII character string. It closes the connection
after sending. It has two different TCP and UDP based
services.
The Network Time Protocol (NTP) is
the most complex and sophisticated of the time protocols,
and it can provide the highest accuracy to a time client
as a result. NTP is built on the IP and UDP. It is evolved
from the Time Protocol and the ICMP (Internet Control
Message Protocol) Timestamp message and is a suitable
replacement for both. NTP supports the compensation
of the transmission delay between server and client.
The protocol includes provisions to specify the characteristics
and estimate the error of the local clock and the time
server to which it may be synchronized. The data packet
includes a 64-bit timestamp containing the time in UTC
seconds since January 1, 1900 with a resolution of 200
picoseconds. NTP provides accuracy of 1 to 50 milliseconds.
For more information, please refer to the NTP
website.
Important
Notice!
The NeTS may affect operations that are dependent
on time information embedded in computers. Users
should decide the suitability of using this programme
and, if necessary, seek expert advice.
The National Metrology Centre shall not be liable to any user
for any loss or damage suffered by the user arising
from disruption to the user’s computer or
the running of any programme installed therein
as a result of using the NeTS. In the event that
National Metrology Centre is found liable by the operation
of law, National Metrology Centre’s maximum liability to the
user for any claim shall be limited to S$1.00.
The NeTS may be disrupted or changed without
advance notification. |
|