Network synchronization products are used to maintain and synchronize timing across a computer network. Network administrators use network synchronization products to manage time-sensitive services such as streaming audio and video, data transfer and encryption, client-server time accuracy, Web conferencing, backup and redundancy, and database communications. Network synchronization products are also used with client computers, printers, and phones with file, printer, and application servers. A network clock is a network synchronization product that use the network time protocol (NTP) standardized in RFC 1305. To synchronize timing across a local area network (LAN), network clocks match NTP with an external source such as a global positioning satellite (GPS) or low-frequency (LF) time signaling. Additional interfaces for network synchronization products include simple network time protocol, daytime protocol (RFC 867), and user datagram protocol/Internet protocol (UDP/IP).
Timers or Master Clocks
Network timers or master clocks are network synchronization products that use a microprocessor and internal network oscillator to synchronize applications that require analog clocking. In simplest terms, oscillators are circuits that use amplification and feedback to generate radio frequency (RF) outputs. Because network timers use microprocessors, they can be manufactured as programmable erasable read-only memory (PROM) or electrically erasable read-only memory (EEPROM). This enables chip designers to program devices that can produce an RF signal after a given timing period. Typically, this timing period begins or ends when a switch actuates the program.
Network synchronization products can be categorized into hardware components and software applications. The proper selection of software and hardware depends on considerations such as time sources, synchronization frequency, time models, network models, and installation specifics. Network synchronization products also include software applications that are designed to display and monitor the times on servers, client computers, and domain controllers. These applications provide management tools to monitor synchronization activities on a network, such as data and file transfers, application-to-database communications.