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GPS timing system (network timing instrument) application of e-government system

2020-11-09 17:20:20 ahjzdz

GPS Timing system ( Network timing instrument ) Application of e-government system

GPS Timing system ( Network timing instrument ) Application of e-government system

Beijing Zhun electronic technology official micro ——ahjzsz

Abstract : With the continuous development of e-government , Many provinces have set up their own government networks , More and more network devices and servers are used , These devices all have their own clocks , It's adjustable , Therefore, the time of all devices and hosts in the network cannot be guaranteed to be synchronized , After long-term operation , The time gap will get bigger and bigger , This kind of deviation has little effect on a single machine , But with the continuous development of various network applications , The demand for time is higher and higher , Time out of sync can cause many unexpected problems , Next we combine the actual network architecture , Discuss NTP The solution in government affairs network .

What is network time service ?

Clock synchronization is also called “ Set the clock ”, In the field of Communications ,“ Sync ” The concept refers to the synchronization of frequencies , That is, the clock frequency and phase synchronization of each node in the network , The error should be in accordance with the relevant standards . Time synchronization refers to the time and time interval of the clock of each node in the network and the clock of each application interface connected through the network and coordinated universal time (UTC) Sync , At least in a local area or metropolitan area network to synchronize with Beijing time . Time synchronization network is the basis of time synchronization , The time synchronization network can be constructed in wired way , It can also be done wirelessly .

TCP/IP Agreement , The protocol used for network synchronization time is NTP agreement , It was made by the United States Delaware University professors designed and implemented , A communication protocol that enables computers on a network to keep time synchronized , Its own transmission is based on UDP, Reserved port number 123,NTP The protocol can estimate the round-trip delay of packets on the network , And can independently estimate the computer clock offset , So as to achieve reliable and accurate time synchronization between computers ,NTP It's a dynamic 、 Stable and fault tolerant protocols , It is used to ensure that the clock accuracy of all devices in the network is within 1ms within . This agreement is in RFC958 In the definition of , after NTP The protocol is constantly modified to add more redundancy and security features , Others related to time synchronization RFC Yes RFC1128,RFC1129,RFC1165,RFC1305,RFC2030.

Maybe some people think that the clock of the computer is a little bit out of order , In fact, this is very wrong , File saving in computer system , File transfer 、 The time stamp in email is based on the computer clock , If you want to do a file search later , Log query , If the system clock doesn't work , Or computers in the same network are not synchronized , It brings a lot of trouble to the follow-up work , Now a lot of backup software , Translation software 、FTP The tools are compared based on the time the file was saved , If time is not uniform , It will make it difficult for these software to work properly .

In Network Management , When we check the operation of various network management software systems in the network , Or when the server logs , It is found that the system time on different devices is different , Want to LOG Information (console Output or syslog Record ) Observe the impact of an event on each device 、 It's very inconvenient to order , This problem can also be configured NTP To solve ,NTP For routers 、 A time synchronization mechanism is provided between the switch and the workstation . Time is in sync , Time records from multiple network devices can be viewed together , More clearly , It is convenient to analyze complex faults and safety events , In addition, authentication in government affairs network 、 maintain 、 management 、 Backup system and other applications require high accuracy of time , For example, the time accuracy requirement of switch and billing is 1s, The time accuracy requirement of network management system is 500s.

NTP There are three working modes of service , The customer / Server mode 、 Broadcast mode and symmetric module .

On the client side / In server mode , The client sends... Periodically NTP Data packets , Visually view the working status according to the tag 、 The result of the event and feedback in time .

System function

After a period of time running , So far, there are general hidden danger data records in the database 24589 strip , It has been rectified 24077 strip , Rectification rate 97.91%; Major hazard data 145 strip , It has been rectified 144 strip , Rectification rate 99.3%, The system provides decision makers with accurate data of security risks , The results of safety investigation are mainly reflected in the safety production accidents 、 fire 、 On top of the traffic accident statistics , According to the survey, two months of data , All kinds of accidents occurred in the city 、 number of casualties 、 Direct economic losses have fallen sharply , City carrying capacity 、 Emergency response capability 、 Security prevention and control capability 、 The capacity of disaster prevention and mitigation has also been greatly improved . A large number of hidden dangers that have not been found in the past can be found and solved , A large number of outstanding problems discovered in the past have been rectified , Some long-standing problems left over by history have been properly dealt with , In order to effectively curb the occurrence of hidden accidents , It has created a safe, stable and harmonious urban environment and played a positive role in promoting .

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