Even when the Internet was in its infancy no more than a few computers connected together, it became apparent the need to synchronize the time. Computers are easily confused especially with the time it can only travel in one direction. Where a communication is sent from a computer and received seems to have arrived before it was sent and this can cause unforeseen problems. Imagine buying an airline ticket only to show up at the airport and find someone who has bought his seat after you did just because he reserved on a computer Acon a slower clock! Dr. David Mills of the University of Delaware, realized the need for a synchronization tool and developed the Network Time Protocol – Network Time Protocol (NTP). Although not the first and only time synchronization protocol is the most used and probably owes its success, now Professor Mills, and his dedicated team for their continued development What began as a protocol synchronization could manage a few milliseconds is now able to keep computer clocks within a few nanoseconds of each other (nano = milli = 1/milesimo 1/milmillonesimo). NTP is hierarchical and is divided into strata.
A clock source is called a Stratum 0, while a server is Stratum 1 NTP, equipment and devices that receive the time from a Stratum 1 server become Stratum 2 and so on. This hierarchical structure means that tens of thousands of devices can be synchronized at once without flooding the NTP server or bandwidth of the network. NTP servers are based on the use of a reference clock. While this can be anything from a wristwatch to a computer system clock does not make sense to use a reference clock that was not exactly himself Most networks using an NTP server using a UTC time source . The UTC, or Coordinated Universal Time is based on the time reported by the incredibly accurate and expensive watches atomic. The time signals of an atomic clock can be set either through the Internet (although the accuracy is variable and depends on the distance), special radio broadcasts issued in several countries (including USA, UK Germany, France and Japan) or through the American GPS (Global Positioning System).
NTP servers distribute this Stratum 0 time source to all devices on the network that connects with the NTP server. The NTP then advance or sustain the system clock to match the timing reference. NTP also has its security measures called authentication. This is a set of encryption keys are used to identify both the client and the server. Unfortunately, authentication is not available in Internet time references and that is why both Microsoft and Novell des sources suggest that hardware be used as timing reference. NTP is currently in version 4 to version 5 in development and is open source and freely available for download through ntp.org Cecilia Chavez is a technical author and specialist in atomic clocks, telecommunications, NTP and synchronization Network Time to help develop dedicated NTP clocks.