EasyManuals Logo
Home>HP>Switch>JD320B

HP JD320B User Manual

HP JD320B
189 pages
To Next Page IconTo Next Page
To Next Page IconTo Next Page
To Previous Page IconTo Previous Page
To Previous Page IconTo Previous Page
Page #56 background image
How NTP works
Figure 17 shows the basic workflow of NTP. Device A and Device B are connected over a network. They
have their own independent system clocks, which need to be automatically synchronized through NTP.
For an easy understanding, assume the following conditions:
• Prior to system clock synchronization between Device A and Device B, the clock of Device A is set
to 10:00:00 am while that of Device B is set to 11:00:00 am.
• Device B is used as the NTP time server (Device A synchronizes its clock to that of Device B).
• It takes 1 second for an NTP message to travel from one device to the other.
Figure 17 Basic work flow of NTP
System clock synchronization includes the following process:
• Device A sends Device B an NTP message, which is timestamped when it leaves Device A. The time
stamp is 10:00:00 am (T1).
• When this NTP message arrives at Device B, it is timestamped by Device B. The timestamp is
11:00:01 am (T2).
• When the NTP message leaves Device B, Device B timestamps it. The timestamp is 11:00:02 am
(T3).
• When Device A receives the NTP message, the local time of Device A is 10:00:03 am (T4).
Up to now, Device A has sufficient information to calculate the following important parameters:
• The roundtrip delay of NTP message: Delay = (T4–T1) – (T3-T2) = 2 seconds.
• Time difference between Device A and Device B: Offset = ((T2-T1) + (T3-T4))/2 = 1 hour.
Based on these parameters, Device A can synchronize its own clock to the clock of Device B.
This is only a rough description of the work mechanism of NTP. For more information, see RFC 1305.
49

Table of Contents

Other manuals for HP JD320B

Questions and Answers:

Question and Answer IconNeed help?

Do you have a question about the HP JD320B and is the answer not in the manual?

HP JD320B Specifications

General IconGeneral
BrandHP
ModelJD320B
CategorySwitch
LanguageEnglish

Related product manuals