With the expansion of distributed computer systems, network time synchronization has increasingly become of critical importance. A network time server provides computer networks with an accurate time resource. By utilizing GPS and radio time and frequency broadcasts it can provide highly precise timing information to client computers. Most time servers utilize the Network Time Protocol to synchronize servers, workstations and general network equipment.
Using NTP Servers For Synchronization
The Network Time Protocol (NTP) has been widely adopted as the standard means of distributing time on computer networks. The protocol is client-server based, whereby a client requests time from a server which duly responds with a time-stamp. NTP includes a number of complex algorithms that can eliminate round-trip delays. It also synchronizes time in a seamless manner by adjusting the tick of a computers systems clock rather than stepped adjustments. This removes problems associated with backward stepped time adjustments.
The Importance of Consistent Time
For many applications, synchronization of computer systems is of critical importance. Many tasks performed by distributed computer systems need to be performed in a predetermined manner. The only way this can be achieved is by synchronizing the time on the computers performing the tasks.
Many other devices in addition to servers and workstations can be synchronized. Devices such as routers and switches, which form part of a networks infrastructure can also obtain time from a time server.
Applications that require tasks to be completed in an ordered predetermined manner often require accurate time. Data-logging applications may need to know the precise time that an event occurred. Distributed transaction processing systems rely on being able to determine exactly when a transaction was generated. Industrial automation, power generation, distribution and smart-grid applications all require accurate time for metering purposes. The telecommunications industry rely on precise time for quality of service of voice, video and broadband services. Modern CCTV systems and digital video recorders, DVR’s rely on accurate time in order to comply with the requirements of law and the provision of evidence.
TimeTools SR Series
TimeTools provide a range of network time server solutions that utilize GPS and radio time sources to provide stratum one operation. The SR series is provided in a 1U high rack-mountable enclosure with a large LCD display for status and configuration information. The SC series comes in a compact, rugged, desktop-type enclosure. TimeTools time servers are available with single or dual LAN options and TCXO options for improved holdover in the event of loss of primary reference signal. They provide an extremely cost-effective and versatile solution to network time synchronization.
All TimeTools SR and SC series models can synchronize with either GPS or radio time references. Indeed a number of models can accept both radio and GPS antennas at the same time to provide a degree of signal redundancy. GPS is generally accepted as the preferred source of time due to availability and better stability. However, many customers opt to utilize MSF or DCF-77 radio references as a backup time source.
http://www.pool.ntp.org/en/ the internet cluster of ntp servers
https://support.microsoft.com/en-us/help/262680/a-list-of-the-simple-network-time-protocol-sntp-time-servers-that-are A list of the Simple Network Time Protocol (SNTP) time servers that are available on the Internet