Abstract: With the continuous development of e-government, many provinces have set up their own government network, network devices and servers used by an increasing number of these devices have their own clock, is adjustable, so all devices and hosts in the network the time can not be guaranteed to be synchronized, after a long run, the time difference will become increasingly large, this bias in stand-alone in the modest impact, but with the continuous development of various network applications, the time demands are also increasing time synchronization will not lead to many unexpected problems, then we combine the actual network architecture, discussed NTP solutions in government affairs network.
Clock synchronization is also called "bell on", in the communications field, "synchronization" refers to the concept of frequency synchronization, i.e. the clock frequency and phase of each node in the network synchronization, the error should comply with the relevant standards. Refers to the interval time synchronization with UTC (UTC) and time synchronization time of each network node clock and the clock of each application interface is connected via a network, and at least to a GMT synchronized within a local or metropolitan area network. Time synchronization is the basis for network time synchronization, time synchronization configuration may take the wired network, a wireless manner may be taken.
Anhui Jing quasi-electronic technology research and development of HR-901GBNTP network time servers using GPS satellite signals and use the Compass dual time service for your computer network technology to provide standard network time service.
TCP / IP protocol, the protocol used for network time synchronization of the NTP protocol, it is a professor at the University of Delaware American design by the implementation of the computers on the network to maintain time synchronization of a communication protocol, the transmission itself based on UDP, reserved port number 123, NTP protocol may estimate the packet round-trip delays on the network, and can estimate the computer clock bias independent, in order to achieve reliable and precise time synchronization between computers, NTP is a dynamic, stable, and fault-tolerant protocol, to ensure All devices in the network clock accuracy error within 1ms. This protocol defined in RFC958, after NTP protocol constantly modified to add more redundancy and security features, time synchronization and other related RFC has RFC1128, RFC1129, RFC1165, RFC1305, RFC2030.
Some may think that the computer's clock a little bias little effect, in fact, this is very wrong, the computer system saved the file, file transfer, electronic mailbox timestamp are based on the clock of the computer, if you later want to find files, log, computer time is not allowed if the system clock, or the same network are not synchronized, tell the follow-up work to bring a lot of trouble, and now a lot of backup software, translation software, FTP tools are time to save the file as a basis for comparison, If the time is not uniform, the software will make it difficult to work.
In network management, we check the operation of the network in a variety of network management software system time, or the server logs, they found that due to the different time systems on different devices, you want to observe a particular message by LOG (console or syslog output record) event inconvenient for each device prejudice, order, etc., this problem can also be solved by configuring the NTP, NTP provides a mechanism for time synchronization between the routers, switches, and workstations. Time synchronization, and record the relevant time on multiple network devices can be put together, the more clearly, to facilitate the analysis of more complex faults and safety events, in addition to the government network application certification, maintenance, management, backup systems, etc. the accuracy of the time is relatively high, such as switches and billing requirements for time accuracy of 1s, the network management system time accuracy requirements 500s.
NTP services into three operating modes, namely client / server mode, broadcast mode and symmetric modules.
In the client / server model, the client sends data packets to NTP periodically, according to the label to visualize the working state, like the event and feedback.
System role
After a period of operation, the database has a total of 24589 general risk data record, which has been the rectification 24077, rectification rate of 97.91%; 145 major hidden data, which has been the rectification 144, the rectification rate of 99.3%, the system provides for decision-makers accurate data security risks, results of the work safety investigation is embodied on production safety accidents, fire, traffic accident statistics, according to the survey data two months, the city's various accidents, casualties and direct economic losses sharply decline, the city carrying capacity, emergency response capabilities, security prevention and control capacity, disaster prevention and reduction is also greatly improved. A large number of risks in the past and did not find the resolve to find, but found a large number of outstanding issues in the past been the rectification, some long-term historical issues are properly addressed, in order to effectively curb risks of accidents, creating a safe and stable and harmonious city environment has played a positive role in promoting.
