NTP: NTP is the short hand name given to the Network Time Protocol; it is a standard protocol for distributing time around the internet and computer networks. Precise time is passed from accurate time references to network time clients for the purpose of synchronisation.
NTP Server: A NTP Server is a device that obtains precise time from an external timing reference such as GPS and provides a precise timing resource to computer networks.
Stratum: The Stratum or level of a NTP time server denotes its position in the network timing heirachy. A stratum 1 NTP server obtains time from an external timing reference. Stratum 2 devices obtain time from stratum 1 devices and pass timing information to the next level and so on.
Jitter: The jitter associated with a timing reference indicates the magnitude of variance, or dispersion, of the signal. Different timing references have different amounts of jitter. The more accurate a timing reference, the lower the jitter value. Jitter is usually measure in milliseconds.
Offset: Offset generally refers to the difference in time between an external timing reference and time on a local machine. The greater the offset, the more inaccurate the timing source is. Synchronised NTP servers will generally have a low offset. Offset is generally measured in milliseconds.
Delay: Delay in a NTP server describes the round-trip delay or latency of a timing message passed from client to server and back again. The time delay is generally measured in milliseconds and is used to calculate adjustments required to account for network delays.
Reference Clock: A NTP reference clock is an external hardware clock that a NTP server utilises for accurate time synchronisation. GPS and radio time and frequency broadcasts are commonly used as NTP reference clocks. The NTP distribution, which is available for LINUX, provides source code to operate a large number of external reference clocks.
MSF: MSF is the call sign of a the UK time and frequency radio broadcast, which is available throughout Britain. The MSF signal is broadcast at 60kHz from Anthorn, Cumbria. NTP server systems utilise the MSF time transmission as a reference for providing accurate time. The term MSF is the call sign of the radio broadcast.
DCF-77: The DCF-77 radio time signal is broadcast from Frankfurt, Germany at 77.5Khz. The signal is a time and frequency broadcast that can be received throughout Germany and much of Western Europe. The broadcast is used by many stratum 1 NTP server systems as a precision timing reference.
GPS: The Global Positioning System (GPS) is primarily intended as a global navigation system. However, GPS also provides a highly accurate precision timing reference that can operate worldwide. The GPS system is widely used as a timing reference for GPS NTP time server equipment.
To conclude, most of the terminology used in computer timing can be confusing and vague. However, most of these phrases are used to describe a relatively simple concept.
Ntp Server Windows 2008
The Network Time Protocol (NTP) was developed to provide a way of synchronising Internet clients to an accurate network time reference. NTP allows the time on client computers to be set to within a fraction of the correct time. The NTP protocol is a suite of programs designed specifically for time synchronisation purposes. The application source code is freely downloadable from the NTP website. Originally developed for the Linux operating system, NTP has since been ported to Microsoft Windows platforms.
Combining an accurate external timing reference with the NTP application provides a highly accurate network timing device. This article describes how to utilise a low-cost GPS receiver in combination with the NTP software distribution to provide an accurate stratum 1 NTP server timing reference.
The NTP source code can be obtained from the NTP website and must be compiled on the local machine. The downloadable NTP tar file extracts to a directory where scripts are available to make compilation and configuration very straight-forward. Linux distributions such as Redhat and Debian install the NTP distribution by default. In order to configure a stratum 1 NTP server an accurate reference clock is required. The NTP software provides a large number of reference clock drivers that can be utilised to interface with a range of hardware timing references. Dedicated hardware timing devices can be prohibitively expensive. However, the popularity of GPS navigation devices has reduced the cost of GPS technology. Low-cost GPS receivers are now readily available from around $100. Many GPS receivers have a RS232 serial communications port, which can easily be connected to a PC. Most GPS receivers utilise the NMEA communications protocol which provides time and location information each second. The timing information can be utilised by the NTP software as an accurate timing reference to provide a stratum 1 NTP server.
The NTP software needs to be compiled with the NMEA reference clock driver to interface with the GPS receiver. Once compiled the application must be configured to utilise the correct serial port. When correctly installed and configured, the NTP application will provide your network with an accurate, stable timing reference.
A NTP server can be utilised to synchronise time on most computer operating systems and network infrastructure. Any network device that has an integrated NTP client can be configured to synchronise time with the NTP server. Generally, clients only need the IP address of the NTP server for synchronisation. With a NTP server, you can synchronise almost any device on your network.
David Evans has sinced written about articles on various topics from Computers and The Internet, Personal Desktop and Computers and The Internet. David L. Evans is an experience author with a number of years experience in the field of computer and network timing systems. Click here, for more information on. David Evans's top article generates over 18100 views. to your Favourites.
Christian Work At Home Opportunities In most cases just a simple Google search will reveal enough information for you to make an educated decision about the validity of a work at home opportunity