TFS NTP80plus, Справочное руководство

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MANUAL P/N 900000165 REV H
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8.2 Understanding NTP
The client computer obtains the NTP protocol by requesting a NTP packet from the NTP Server.
The Software that requests the packet handles reception, maintenance and distribution of the
time on the computers where it is installed. All Time & Frequency Solutions NTP Time Servers
are supplied, with client software as standard for a range of operating systems & platforms.
Most client software compensates for the delays over the network, and synchronises the
computers with an accuracy of typically 1ms to the NTP Server. For larger networks such as
WANs delays of up to 10ms can be expected.
Server
Timeline
Client
Timeline
T2
(Receive)
T3
(Transmit)
T4 T1
(Originate)
Figure 1 – Basic Method of Delay Calculation Over a Network
Another commonly used protocol is the SNTP (Simple Network Time Protocol). As the name
suggest this is a simpler way of obtaining time over a network, but this method does not
compensate for delays and therefore is not as accurate.
All Time & Frequency Solutions supplied client software uses the NTP protocol, and therefore
provides a more reliable solution than SNTP.