CN112260790B - Time synchronization method and system based on NTP protocol - Google Patents
Time synchronization method and system based on NTP protocol Download PDFInfo
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- CN112260790B CN112260790B CN202011174978.1A CN202011174978A CN112260790B CN 112260790 B CN112260790 B CN 112260790B CN 202011174978 A CN202011174978 A CN 202011174978A CN 112260790 B CN112260790 B CN 112260790B
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- H04J3/0638—Clock or time synchronisation among nodes; Internode synchronisation
- H04J3/0658—Clock or time synchronisation among packet nodes
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Abstract
The invention provides a time synchronization method and a system based on NTP protocol, wherein the method comprises the following steps: step 1: simultaneously starting an NTP server and a client on preset network equipment; step 2: and according to the NTP server of the preset network equipment, time synchronization is carried out on the front-end equipment of the preset network equipment in the local area network. According to the method, the preset network equipment provides the NTP service function, the pressure of the main NTP server is dispersed, the time synchronization function among the network equipment is realized, and the normal operation of the network equipment is ensured.
Description
Technical Field
The invention relates to the technical field of digital information transmission, in particular to a time synchronization method and system based on an NTP protocol.
Background
In the same local area network, a plurality of devices can work simultaneously, and continuous protocol interaction needs exist in the period, so that time consistency and accuracy among the devices are required to be kept. Because the time crystal oscillator specifications of the equipment are different, errors are gradually accumulated and increased along with the time, and time synchronization is needed.
At present, the NTP (Network Time Protocol) technology is mainly adopted to solve the problem of clock synchronization of the internet at present; NTP is developed by professor David l.mills of the university of telawa, usa, and is a protocol mainly used for synchronizing computer time, which can synchronize a computer with a server or a clock source (such as a quartz clock, a GPS, etc.), and has the advantages of providing high-precision time correction (the difference between the standard and the standard on a LAN is less than 1 millisecond, and the difference between the standard and the standard on a WAN is tens of milliseconds), preventing malicious protocol attack by means of encryption confirmation, and the like, so NTP has become a recognized clock synchronization tool on the global internet at present.
However, at present, a large number of devices synchronize with only one or several common NTP servers, which easily causes the server to be over-stressed, resulting in partial synchronization failure.
Therefore, in order to relieve the pressure of the main NTP server, a time synchronization method and system based on the NTP protocol are needed.
Disclosure of Invention
The invention provides a time synchronization method based on an NTP protocol, which is used for relieving the pressure of a main NTP server.
The invention provides a time synchronization method based on NTP protocol, which comprises the following steps:
step 1: simultaneously starting an NTP server and a client on preset network equipment;
step 2: and according to the NTP server of the preset network equipment, time synchronization is carried out on the front-end equipment of the preset network equipment in the local area network.
Further, in step 1, the preset network device that simultaneously starts the NTP server and the client is a part of or all of the network devices in the local area network.
Further, in step 1, the client started on the preset network device is connected to a main NTP server.
Further, the method further comprises:
and step 3: and utilizing the client side of the preset network equipment connected with the main NTP server to synchronize the time of the preset network equipment in a timing manner.
Further, the step 2: according to the NTP server of the preset network equipment, time synchronization is carried out on the front-end equipment of the preset network equipment in the local area network, and the following steps are carried out:
step S21: configuring an IP address of the front-end device of the preset network device to the main NTP server of the preset network device;
step S22: and configuring the IP address of the front-end equipment to the NTP server of the preset network equipment on the main NTP server to serve as a sub NTP server, and performing time synchronization on other front-end equipment of the preset network equipment by using the sub NTP server.
Further, before the step 1, the method also comprises the steps of A1-A3:
step A1: selecting any two preset network devices in the local area network, transmitting a signal to a second preset network device in the two preset network devices by a first preset network device in the two preset network devices through a GPS communication module, and determining a signal distance between the two preset network devices according to the following formula;
S1＝C*(T1-T2)-C*γ
wherein S1 is a signal distance between the two preset network devices, C is a speed of light, T1 is a GPS time corresponding to a first preset network device of the two preset network devices transmitting a signal, T2 is a GPS time corresponding to a second preset network device of the two preset network devices transmitting a signal, and γ is a preset reaction duration;
step A2: determining a calculated distance between the two preset network devices:
wherein S2 is a calculated distance between the two network devices, (x1, y1, z1) is a three-dimensional coordinate value of a first preset network device in the two preset network devices in the terrestrial coordinate system, (x2, y2, z2) is a three-dimensional coordinate value of a second preset network device in the two preset network devices in the terrestrial coordinate system, F1 is a satellite clock time corresponding to the first preset network device in the two preset network devices transmitting a signal, and F2 is a satellite clock time corresponding to the second preset network device in the two preset network devices transmitting a signal;
step A3: judgment of
Whether the value of (d) is less than a threshold value;
if the time difference between the two preset network devices is smaller than the preset time difference, otherwise, the time difference between the two preset network devices is small, the two preset network devices are controlled to send out early warning, the time of the two preset network devices is adjusted to be synchronous, and the step 2 is continuously executed.
The time synchronization method based on the NTP protocol provided by the embodiment of the invention has the following beneficial effects: the preset network equipment provides the NTP service function, the pressure of the main NTP server is dispersed, the time synchronization function among the network equipment is realized, and the normal operation of the network equipment is ensured.
The invention also provides a time synchronization system based on the NTP protocol, which comprises the following steps:
the simultaneous opening module is used for simultaneously opening the NTP server and the client on the preset network equipment;
and the time synchronization module is used for carrying out time synchronization on the front-end equipment of the preset network equipment in the local area network according to the NTP server of the preset network equipment.
Further, the preset network device of the simultaneous opening module is a part of or all of the network devices in the local area network.
Further, the client started by the simultaneous starting module on the preset network device is connected with the main NTP server.
Further, the client of the preset network device connected to the main NTP server is configured to synchronize the time of the network device in a timed manner.
Further, the time synchronization module includes:
an IP address configuration unit, configured to configure an IP address of a front-end device of the preset network device to the main NTP server of the preset network device;
and the time synchronization unit is used for configuring the IP address of the front-end equipment to the NTP server of the preset network equipment on the main NTP server to serve as a sub NTP server, and performing time synchronization on other front-end equipment of the preset network equipment by using the sub NTP server.
The time synchronization system based on the NTP protocol provided by the embodiment of the invention has the following beneficial effects: the preset network equipment provides the NTP service function, the pressure of the main NTP server is dispersed, the time synchronization function among the network equipment is realized, and the normal operation of the network equipment is ensured.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:
fig. 1 is a schematic flow chart of a time synchronization method based on NTP protocol in an embodiment of the present invention;
fig. 2 is a block diagram of a time synchronization system based on the NTP protocol in an embodiment of the present invention.
Detailed Description
The preferred embodiments of the present invention will be described in conjunction with the accompanying drawings, and it will be understood that they are described herein for the purpose of illustration and explanation and not limitation.
The embodiment of the invention provides a time synchronization method based on an NTP protocol, as shown in figure 1, the method comprises the following steps:
step 1: simultaneously starting an NTP server and a client on preset network equipment;
step 2: and according to the NTP server of the preset network equipment, time synchronization is carried out on the front-end equipment of the preset network equipment in the local area network.
The working principle of the technical scheme is as follows: in step 1, the preset network devices that simultaneously start the NTP server and the client are part of or all network devices in the local area network. It should be noted that, the number of preset network devices for simultaneously starting the NTP server and the client is not specifically limited in the present invention. In a specific implementation, the preset network device that simultaneously starts the NTP server and the client may be all network devices having front-end devices, or may be specified by a user, which is not limited in the present invention.
Firstly, simultaneously starting an NTP server function and a client function on preset network equipment; and then, according to the NTP server function of the preset network equipment, time synchronization is carried out on the front-end equipment of the preset network equipment in the local area network. The front-end device is, for example, a network camera.
The beneficial effects of the above technical scheme are: the preset network equipment provides the NTP service function, the pressure of the main NTP server is dispersed, the time synchronization function among the network equipment is realized, and the normal operation of the network equipment is ensured.
In one embodiment, in step 1, the client opened on the preset network device connects with a main NTP server.
The working principle of the technical scheme is as follows: the method further comprises the following steps:
and step 3: and utilizing the client side of the preset network equipment connected with the main NTP server to synchronize the time of the preset network equipment in a timing manner.
The client part started on the preset network equipment is responsible for connecting the main NTP server, and the synchronization is carried out at regular time, so that the time accuracy of the equipment is ensured. In a specific implementation, a main NTP server may be requested for multiple times at preset time intervals based on the NTP protocol, and an average value of the multiple times is obtained to obtain the synchronization time.
The beneficial effects of the above technical scheme are: the method for time synchronization of the preset network equipment is provided, and the time accuracy of the equipment can be ensured.
In one embodiment, the step 2: according to the NTP server of the preset network equipment, time synchronization is carried out on the front-end equipment of the preset network equipment in the local area network, and the following steps are carried out:
step S21: configuring an IP address of the front-end device of the preset network device to the main NTP server of the preset network device;
step S22: and configuring the IP address of the front-end equipment to the NTP server of the preset network equipment on the main NTP server to serve as a sub NTP server, and performing time synchronization on other front-end equipment of the preset network equipment by using the sub NTP server.
The working principle of the technical scheme is as follows: the NTP server opened on the preset network equipment serves as a sub NTP server, and other front-end equipment can configure an IP address on the sub NTP to perform time synchronization and guarantee time unification.
The beneficial effects of the above technical scheme are: the specific steps of time synchronization of the front-end equipment of the preset network equipment in the local area network are provided according to the NTP server of the preset network equipment.
In one embodiment, before the step 1, the method further comprises the steps of A1-A3:
step A1: selecting any two preset network devices in the local area network, transmitting a signal to a second preset network device in the two preset network devices by a first preset network device in the two preset network devices through a GPS communication module, and determining a signal distance between the two preset network devices according to the following formula;
S1＝C*(T1-T2)-C*γ
wherein S1 is a signal distance between the two preset network devices, C is a speed of light, T1 is a GPS time corresponding to a first preset network device of the two preset network devices transmitting a signal, T2 is a GPS time corresponding to a second preset network device of the two preset network devices transmitting a signal, and γ is a preset reaction duration;
gamma is generally preset to be 0 and cannot exceed 1ms at most;
step A2: determining a calculated distance between the two preset network devices:
wherein S2 is a calculated distance between the two network devices, (x1, y1, z1) is a three-dimensional coordinate value of a first preset network device in the two preset network devices in the terrestrial coordinate system, (x2, y2, z2) is a three-dimensional coordinate value of a second preset network device in the two preset network devices in the terrestrial coordinate system, F1 is a satellite clock time corresponding to the first preset network device in the two preset network devices transmitting a signal, and F2 is a satellite clock time corresponding to the second preset network device in the two preset network devices transmitting a signal;
step A3: judgment of
Whether the value of (d) is less than a threshold value, which is typically 0.01%;
if the time difference between the two preset network devices is smaller than the preset time difference, otherwise, the time difference between the two preset network devices is small, the two preset network devices are controlled to send out early warning, the time of the two preset network devices is adjusted to be synchronous, and the step 2 is continuously executed.
The beneficial effects of the above technical scheme are: the technology can be used for quickly and simply carrying out time synchronization on the front-end equipment of the preset network equipment in the local area network, and in the process of carrying out time synchronization on the front-end equipment of the preset network equipment, only two comparisons are needed, so that the comparison process becomes simple, the operability is strong, the efficiency is extremely high, in addition, a clear calculation mode is given in the process, the process can be controlled through a computer, the automation is completely realized, and the manual control cost is reduced.
As shown in fig. 2, an embodiment of the present invention provides a time synchronization system based on the NTP protocol, including:
a simultaneous starting module 201, configured to start an NTP server and a client on a preset network device at the same time;
a time synchronization module 202, configured to perform time synchronization on the front-end device of the preset network device in the local area network according to the NTP server of the preset network device.
The working principle of the technical scheme is as follows: the preset network device having the simultaneous enabling module 201 is a part of or all network devices in a local area network. It should be noted that, the number of preset network devices for simultaneously starting the NTP server and the client is not specifically limited in the present invention. In a specific implementation, the preset network device that simultaneously starts the NTP server and the client may be all network devices having front-end devices, or may be specified by a user, which is not limited in the present invention.
In the present invention, the simultaneous opening module 201 simultaneously opens the NTP server and the client on the preset network device; the time synchronization module 202 performs time synchronization on the front-end device of the network device in the local area network according to the NTP server of the network device.
The beneficial effects of the above technical scheme are: the preset network equipment provides the NTP service function, the pressure of the main NTP server is dispersed, the time synchronization function among the network equipment is realized, and the normal operation of the network equipment is ensured.
In one embodiment, the client started by the simultaneous start module 201 on the preset network device is connected with a main NTP server.
The working principle of the technical scheme is as follows: and the client of the preset network equipment connected with the main NTP server is used for synchronizing the time of the network equipment in a timing manner.
The client part started on the preset network equipment is responsible for connecting the main NTP server, and the synchronization is carried out at regular time, so that the time accuracy of the equipment is ensured.
The beneficial effects of the above technical scheme are: by means of the client started on the preset network equipment, the time synchronization can be carried out on the preset network equipment so as to ensure the accuracy of the time of the equipment.
In one embodiment, the time synchronization module 202 includes:
an IP address configuration unit, configured to configure an IP address of a front-end device of the preset network device to the main NTP server of the preset network device;
and the time synchronization unit is used for configuring the IP address of the front-end equipment to the NTP server of the preset network equipment on the main NTP server to serve as a sub NTP server, and performing time synchronization on other front-end equipment of the preset network equipment by using the sub NTP server.
The working principle of the technical scheme is as follows: the NTP server opened on the preset network equipment serves as a sub NTP server, and other front-end equipment can configure the IP address on the sub NTP to carry out time synchronization and guarantee time unification.
The beneficial effects of the above technical scheme are: by means of the IP address configuration unit and the time synchronization unit, the time synchronization can be carried out on the front-end equipment of the preset network equipment in the local area network according to the NTP server of the preset network equipment.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.
Claims (8)
1. A time synchronization method based on NTP protocol, characterized in that the method performs the following steps:
step 1: simultaneously starting an NTP server and a client on preset network equipment;
step 2: according to the NTP server of the preset network equipment, time synchronization is carried out on front-end equipment of the preset network equipment in a local area network;
wherein the step 2: according to the NTP server of the preset network equipment, time synchronization is carried out on the front-end equipment of the preset network equipment in the local area network, and the following steps are carried out:
step S21: configuring the IP address of the front-end equipment of the preset network equipment to a main NTP server of the preset network equipment;
step S22: configuring the IP address of the front-end equipment to the NTP server of the preset network equipment on the main NTP server as a sub NTP server, and performing time synchronization on other front-end equipment of the preset network equipment by using the sub NTP server;
wherein, before the step 1, the method also comprises the steps A1-A3:
step A1: selecting any two preset network devices in the local area network, transmitting a signal to a second preset network device in the two preset network devices by a first preset network device in the two preset network devices through a GPS communication module, and determining a signal distance between the two preset network devices according to the following formula;
S1＝C*(T1-T2)-C*γ
wherein S1 is a signal distance between two preset network devices, C is a speed of light, T1 is a GPS time corresponding to a first preset network device of the two preset network devices transmitting a signal, T2 is a GPS time corresponding to a second preset network device of the two preset network devices transmitting a signal, and γ is a preset reaction duration;
step A2: determining a calculated distance between two of the preset network devices:
wherein S2 is a calculated distance between two of the preset network devices, (x1, y1, z1) is a three-dimensional coordinate value of a first preset network device in the two preset network devices in the terrestrial coordinate system, (x2, y2, z2) is a three-dimensional coordinate value of a second preset network device in the two preset network devices in the terrestrial coordinate system, F1 is a satellite clock time corresponding to the first preset network device in the two preset network devices transmitting a signal, and F2 is a satellite clock time corresponding to the second preset network device in the two preset network devices transmitting a signal;
step A3: judgment of
Whether the value of (d) is less than a threshold value;
if the time difference between the two preset network devices is smaller than the preset time difference, otherwise, the time difference between the two preset network devices is small, the two preset network devices are controlled to give out early warning, the time of the two preset network devices is adjusted to be synchronous, and the step 2 is continuously executed.
2. The method according to claim 1, wherein in step 1, the preset network devices that simultaneously open the NTP server and the client are part of or all network devices in the local area network.
3. The method according to claim 1, wherein in said step 1, said client turned on said predetermined network device is connected with a primary NTP server of said predetermined network device.
4. The method of claim 3, wherein the method further comprises:
and step 3: and utilizing the client side of the preset network equipment connected with the main NTP server to synchronize the time of the preset network equipment in a timing manner.
5. A time synchronization system based on NTP protocol, comprising:
the simultaneous opening module is used for simultaneously opening the NTP server and the client on the preset network equipment;
the time synchronization module is used for carrying out time synchronization on the front-end equipment of the preset network equipment in the local area network according to the NTP server of the preset network equipment;
wherein, according to the NTP server of the preset network device, time synchronization is performed on the front-end device of the preset network device in the local area network, and the following steps are performed:
step S21: configuring the IP address of the front-end equipment of the preset network equipment to a main NTP server of the preset network equipment;
step S22: configuring the IP address of the front-end equipment to the NTP server of the preset network equipment on the main NTP server as a sub NTP server, and performing time synchronization on other front-end equipment of the preset network equipment by using the sub NTP server;
before the NTP server and the client are started simultaneously on the preset network device, the method further includes steps a 1-A3:
step A1: selecting any two preset network devices in the local area network, transmitting a signal to a second preset network device in the two preset network devices by a first preset network device in the two preset network devices through a GPS communication module, and determining a signal distance between the two preset network devices according to the following formula;
S1＝C*(T1-T2)-C*γ
wherein S1 is a signal distance between two preset network devices, C is a speed of light, T1 is a GPS time corresponding to a first preset network device of the two preset network devices transmitting a signal, T2 is a GPS time corresponding to a second preset network device of the two preset network devices transmitting a signal, and γ is a preset reaction duration;
step A2: determining a calculated distance between two of the preset network devices:
wherein S2 is a calculated distance between two of the preset network devices, (x1, y1, z1) is a three-dimensional coordinate value of a first preset network device in the two preset network devices in the terrestrial coordinate system, (x2, y2, z2) is a three-dimensional coordinate value of a second preset network device in the two preset network devices in the terrestrial coordinate system, F1 is a satellite clock time corresponding to the first preset network device in the two preset network devices transmitting a signal, and F2 is a satellite clock time corresponding to the second preset network device in the two preset network devices transmitting a signal;
step A3: judgment of
Whether the value of (d) is less than a threshold value;
if the time difference between the two preset network devices is smaller than the preset time difference, otherwise, the time difference between the two preset network devices is small, the two preset network devices are controlled to give out early warning, the time of the two preset network devices is adjusted to be synchronous, and the NTP server side according to the preset network devices is continuously executed, so that the time synchronization operation is carried out on the front-end device of the preset network devices in the local area network.
6. The system of claim 5, wherein the predetermined network device of the simultaneous activation module is a part of or all of the network devices in a local area network.
7. The system of claim 5, wherein the client initiated by the simultaneous initiation module on the provisioning network device is connected to a primary NTP server.
8. The system of claim 7 wherein said client of said predetermined network device connected to said primary NTP server is configured to synchronize the time of said network device on a timed basis.
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| CN202940822U (en) * | 2012-11-28 | 2013-05-15 | 中国舰船研究设计中心 | Marine local area network time unification system |
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| CN104639399A (en) * | 2015-02-03 | 2015-05-20 | 杭州华三通信技术有限公司 | Method and device for detecting plurality of primary time servers |
| CN109257133A (en) * | 2018-09-14 | 2019-01-22 | 武汉虹信通信技术有限责任公司 | A kind of the whole network clock synchronizing method and device applied to LTE rail transit network |
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| CN104993899A (en) * | 2015-06-23 | 2015-10-21 | 浪潮软件集团有限公司 | Time synchronization method, device and system |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202940822U (en) * | 2012-11-28 | 2013-05-15 | 中国舰船研究设计中心 | Marine local area network time unification system |
| CN104199280A (en) * | 2014-09-23 | 2014-12-10 | 中国电子科技集团公司第二十九研究所 | Time synchronization error measurement method based on differential GPS (global positioning system) |
| CN104639399A (en) * | 2015-02-03 | 2015-05-20 | 杭州华三通信技术有限公司 | Method and device for detecting plurality of primary time servers |
| CN109257133A (en) * | 2018-09-14 | 2019-01-22 | 武汉虹信通信技术有限责任公司 | A kind of the whole network clock synchronizing method and device applied to LTE rail transit network |
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