WO2015169045A1 - Time synchronization method, device and system, and storage medium - Google Patents

Abstract

A time synchronization method, device and system, and a storage medium. The method may comprise: a network entry node records a first time value at which a Precision Time Protocol (PTP) data packet enters the network entry node; the network entry node updates a correction value of a correction field in the PTP data packet according to the first time value, so as to obtain a first updated PTP data packet; and the network entry node sends the first updated PTP data packet to a network, so that the network sends the first updated PTP data packet to a network exit node.

Description

Time synchronization method, device and system, and storage medium Technical field

The present invention relates to network communication technologies, and in particular, to a time synchronization method, device and system, and storage medium.

Background technique

In the current mobile communication network, accurate time synchronization is maintained between the base stations to ensure that the user does not have a line drop or the like during the movement. Among the existing communication devices, the precision clock synchronization protocol standard of the network measurement and control system proposed by the Institute of Electrical and Electronics Engineers (IEEE) in 2002 and modified in 2007, is widely used. Also known as the IEEE 1588 protocol.

In this protocol, each transmitting node device is treated as a transparent clock, and each node performs processing on a Precision Time Protocol (PTP) packet to calculate the dwell time of the node; then the network path is The dwell times of all the nodes in the middle are added to obtain the dwell time of the entire network, and finally the time synchronization is performed according to the obtained dwell time of the entire network.

In the process of implementing the above technical solution, the following problems exist:

First, multiple transit node devices in the network calculate their own dwell time, which will increase the overhead of network resources;

Secondly, the cascading mode of multiple transmitting node devices in the network accumulates the error caused by the delay of the transmission path delay or the network jitter of each transmitting node device, thereby reducing the dwell time precision of the entire network;

There is also a need to compensate for the asymmetry of the bidirectional transmission path of the transmission medium between each pair of transmission node devices in the network, thereby increasing the workload of the network.

Summary of the invention

To solve the above technical problem, an embodiment of the present invention is to provide a time synchronization method, device, system, and storage medium, which can reduce network resource overhead when calculating the dwell time of the entire network; and improve the dwell time of the entire network. The accuracy of the calculations, as well as reducing the workload of the network.

The technical solution of the embodiment of the present invention is implemented as follows:

In a first aspect, an embodiment of the present invention provides a method for time synchronization, where the method includes:

The network access node records the first time value of the precise time protocol PTP data packet entering the network access node;

Updating, by the network access node, a correction value of the modified domain field in the PTP data packet according to the first time value, to obtain a first updated PTP data packet;

The network access node sends the first updated PTP data packet to a network, so that the network sends the first updated PTP data packet to an outgoing network node.

According to the first possible implementation, in combination with the first aspect, the network access node updates, according to the first time value, a correction value of the modified domain field in the PTP data packet, including:

The network access node extracts a correction value of the correction domain field in the PTP data packet according to the format of the PTP data packet;

The network access node subtracts the correction value from the first time value to obtain a first correction value;

The network access node updates the first correction value to the correction domain field according to a format of the PTP data packet.

According to the second possible implementation, in combination with the first aspect, the network access node records the first time value of the PTP data packet entering the network access node, including:

The network access node records the first time value when the PTP data packet enters from an input interface of the network access node that is close to the physical layer.

According to a third possible implementation, combining the first aspect, the first or the second possible In any one of the implementation manners, after the network access node records the first time value of the PTP data packet entering the network access node, and updating, at the network access node, the PTP data packet according to the first time value. Before modifying the correction value of the domain field, the method further includes:

The network access node checks the PTP data packet to determine that the PTP data packet is incorrect, and ends the current processing.

In a second aspect, an embodiment of the present invention provides a method for time synchronization, where the method includes:

The outbound network node records the precise time protocol PTP data packet to output the second time value of the outgoing network node; the PTP data packet is received by the outgoing network node from the network, and is sent by the network access node in the network;

And the egress node updates the correction value of the correction domain field in the PTP data packet according to the second time value to obtain a second update PTP data packet.

According to the first possible implementation, in combination with the second aspect, the outgoing node updates the correction value of the modified domain field in the PTP data packet according to the second time value, including:

And the egress node extracts a correction value of the correction domain field in the PTP data packet according to the format of the PTP data packet;

And the outgoing node adds the correction value to the second time value to obtain the second correction value;

The egress node updates the second correction value to the correction domain field according to a format of the PTP data packet.

According to the second possible implementation, in combination with the second aspect, the egress node records the second time value of the PTP data packet outputting the egress node, including:

The egress node records the second time value when the PTP data packet is output from an output interface of the egress node near the physical layer.

According to a third possible implementation manner, in combination with any one of the second aspect, the first or the second possible implementation manner, the PTP data packet is recorded at the outgoing network node, and the outgoing network is output After the second time value of the node, and before the network node updates the correction value of the correction domain field in the PTP data packet according to the second time value, the method further includes:

The outgoing node checks the PTP data packet to determine that the PTP data packet is incorrect, and ends the current processing.

In a third aspect, an embodiment of the present invention provides a network access node, where the network access node includes: a first recording unit, a first update unit, and a sending unit, where

The first recording unit is configured to record a first time value of the precise time protocol PTP data packet entering the network access node;

The first update unit is configured to update a correction value of the correction domain field in the PTP data packet according to the first time value obtained by the first recording unit, to obtain a first update PTP data packet;

The sending unit is configured to send the first updated PTP data packet to a network, so that the network sends the first updated PTP data packet to an outgoing node.

According to the first possible implementation, in combination with the third aspect, the first update unit includes: a first extraction module, a first calculation module, and a first update module, where

The first extraction module is configured to extract a correction value of the correction domain field in the PTP data packet according to the format of the PTP data packet;

The first calculating module is configured to subtract the first time value from the correction value to obtain a first correction value;

The first update module is configured to update the first correction value to the correction domain field in accordance with a format of the PTP data packet.

According to a second possible implementation, in combination with the third aspect, the first recording unit is configured to record the first time value when the PTP data packet enters from an input interface of the network node close to the physical layer .

According to a third possible implementation, in combination with any one of the third aspect, the first or the second possible implementation, the network access node further includes a first check unit, configured to When the PTP data packet is checked and it is determined that the PTP data packet is incorrect, the end processing is triggered.

In a fourth aspect, an embodiment of the present invention provides an outbound network node, where the outbound network node includes: a second recording unit and a second update unit, where

The second recording unit is configured to: record a precise time protocol PTP data packet to output a second time value of the outgoing network node; the PTP data packet is received by the outgoing network node from the network, and the network is received by the network The network node sends;

The second update unit is configured to update the correction value of the correction domain field in the PTP data packet according to the second time value to obtain a second update PTP data packet.

According to the first possible implementation, in combination with the fourth aspect, the second update unit includes: a second extraction module, a second calculation module, and a second update module, where

The second extraction module is configured to extract a correction value of the correction domain field in the PTP data packet according to the format of the PTP data packet;

The second calculation module is configured to add the correction value to the second time value to obtain the second correction value;

The second update module is configured to update the second correction value to the correction domain field according to a format of the PTP data packet.

According to the second possible implementation, in combination with the fourth aspect, the second recording unit is specifically configured to record the second when the PTP data packet is output from an output interface of the outbound network node close to the physical layer. Time value.

According to a third possible implementation manner, in combination with any one of the fourth aspect, the first or the second possible implementation manner, the out network node further includes: a second verification unit, configured to When the PTP data packet is checked and it is determined that the PTP data packet is incorrect, the end processing is triggered.

In a fifth aspect, an embodiment of the present invention provides a system for time synchronization, where the system includes an ingress node and an egress node, where

The network access node is configured to record a precise time protocol PTP data packet to enter the network access node. a first time value; updating a correction value of the correction domain field in the PTP data packet according to the first time value to obtain a first update PTP data packet; and sending the first update PTP data packet to the network So that the network sends the first updated PTP data packet to an outgoing node;

The egress node is configured to record a second time value of the first update PTP data packet outputting the egress node, and update a correction domain field in the first update PTP data packet according to the second time value Correct the value to get the second update PTP packet.

According to the first possible implementation manner, in combination with the fifth aspect, the network access node is further configured to check the PTP data packet, and when the PTP data packet is determined to be incorrect, the current processing ends.

According to the second possible implementation, in combination with the fifth aspect, the out network node is further configured to check the first update PTP data packet, and determine that the first update PTP data packet is incorrect, and end the current deal with.

The embodiment of the invention further provides a storage medium in which a computer program is stored, the computer program being configured to perform the aforementioned method of time synchronization.

The method, device and system for time synchronization provided by the embodiments of the present invention calculate the dwell time of the transport network only by the network access node and the egress node of the transport network, so that each node in the transport network is not required to calculate each The dwell time reduces the resource overhead in the transport network; and it does not accumulate the computational errors caused by each node in the transport network calculating its own dwell time, and improves the calculation accuracy of the dwell time of the transport network; It is even more unnecessary to consider the asymmetry of the two-way transmission path of the transmission medium between each node in the transmission network, thereby reducing the workload of the network.

DRAWINGS

FIG. 1 is a schematic diagram of an application scenario according to an embodiment of the present invention;

2 is a schematic flowchart of a method for time synchronization according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a method for updating a PTP according to a first time value according to an embodiment of the present invention; According to the flow chart of the correction value of the correction domain field in the package;

4 is a schematic flowchart diagram of another method for time synchronization according to an embodiment of the present invention;

FIG. 5 is a schematic flowchart of a modified value of a modified domain field in a PTP data packet according to a second time value according to an embodiment of the present invention;

FIG. 6 is a schematic flowchart diagram of a method for time synchronization according to an embodiment of the present disclosure;

FIG. 7 is a schematic structural diagram of a network access node according to an embodiment of the present disclosure;

FIG. 8 is a schematic structural diagram of another network access node according to an embodiment of the present disclosure;

FIG. 9 is a schematic structural diagram of an outgoing network node according to an embodiment of the present disclosure;

FIG. 10 is a schematic structural diagram of another network outlet node according to an embodiment of the present disclosure;

FIG. 11 is a schematic structural diagram of hardware of a network access node according to an embodiment of the present disclosure;

FIG. 12 is a schematic structural diagram of hardware of an outgoing network node according to an embodiment of the present disclosure;

FIG. 13 is a schematic structural diagram of a system for time synchronization according to an embodiment of the present invention.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described in the following with reference to the accompanying drawings.

In the embodiment of the present invention, in the entire network, only the ingress network node and the egress node perform timestamp processing on the precise time protocol data packet, which is equivalent to treating the entire network as a transparent clock and using the ingress network node as a data packet. The entry, the outbound network node is used as the egress of the data packet, ignoring the processing of the network dwell time in the precise time protocol data packet by other nodes in the network, thereby avoiding the network resource caused by each node in the network calculating the network dwell time. The overhead of ignoring the accumulation error of each transmitting node device in the network, thereby avoiding the degradation of the network dwell time accuracy; ignoring the compensation of the bidirectional transmission path delay asymmetry of the transmission medium at both ends of the entire network, thereby reducing the network work. the amount.

FIG. 1 is an exemplary application scenario of an embodiment of the present invention. The scenario may include device A 110 and device B 120, and device A 110 and device, which need to perform time synchronization. Transmission network 100 between B 120. The transport network 100 may be represented by a dashed box area, which may include, but is not limited to, an ingress node 101 that is connected to the device A 110, an outbound node 102 that is connected to the device B 120, and other nodes 103 in the transport network. Briefly, other nodes 103 within the network are represented by cloud blocks. Those skilled in the art can appreciate that the embodiments of the present invention are not limited to the above scenarios, but can also be applied to other arbitrary scenarios.

It should be noted that the transmission network in the scenario shown in FIG. 1 may be a wired network or a wireless network, or may be a mobile network, etc., which is not limited in this embodiment of the present invention.

Referring to FIG. 2, a method for time synchronization according to an embodiment of the present invention may be applied to an ingress node in a transmission network of the application scenario shown in FIG. 1. It can be understood that different network partitions may have corresponding entries. Nodes, therefore, the entry node is a relative concept. The method can include:

S201: The ingress network node records a first time value of the precise time protocol PTP data packet entering the network access node.

Illustratively, in the scenario shown in FIG. 1, it may be set to require time synchronization between device A and device B. Therefore, the ingress network node can find the PTP data packet according to the feature field of the PTP data packet from the data stream sent by the device A, and can record the first time value of the PTP data packet entering the network access node, and specifically can use the network access time. The first time value is saved in the form of a stamp.

Preferably, the network access node may record the first time value at any one of the PTP data packets at the input end; preferably, in the embodiment of the present invention, the network access node may be in the PTP data packet from the network access node. The first time value is recorded when an input interface near the physical layer enters.

S202: The network access node updates, according to the first time value, a correction value of the correction domain field in the PTP data packet, to obtain a first update PTP data packet.

Illustratively, the network access node updates the correction value of the modified domain field in the PTP data packet according to the first time value, as shown in FIG. 3, which includes:

S2021: The network access node extracts a correction value of the correction domain field in the PTP data packet according to the format of the PTP data packet.

It can be understood that since the PTP data packet conforms to the IEEE1588 protocol and has a fixed data format, the network access node can extract the correction value from the modified domain field of the PTP data packet according to a fixed data format. The specific implementation method is a conventional implementation means of those skilled in the art, and details are not described herein again.

S2022: The network access node subtracts the modified value from the first time value to obtain a first correction value.

Specifically, in this embodiment, the first time value saved in the form of the timestamp of the network is obtained by using the S2021 to obtain the correction value, so that the modified value after the network node is updated can be obtained. In order to clearly explain the technical solution, in this embodiment, the modified value of the network access node obtained by the network access node through S2022 is referred to as a first correction value, and those skilled in the art can understand that, in the following description, unless There is a special description, otherwise the first correction value is used to indicate the correction value of the network node obtained by the network node through S2022 after updating.

S2023: The network access node updates the first correction value to the correction domain field according to the format of the PTP data packet.

Specifically, after obtaining the first correction value, the network access node may change the original correction value in the correction domain field to the first correction value according to the format of the PTP data packet, thereby completing the update of the PTP data packet by the network access node, Thereby obtaining the first update PTP data packet.

Exemplarily, between S201 and S202, the method may further include: the ingress network node checks the PTP data packet, and determines whether the PTP data packet is correct: when the PTP data packet is correct, proceed to execute S202. When the PTP data packet is incorrect, the current processing is ended, for example, discarding the PTP data packet, and waiting for the arrival of the next PTP data packet;

Specifically, the network access node may be different according to the network layer where the PTP data packet is located. And the format of the data stream encapsulating the PTP data packet is different, and the corresponding verification technology may be used for verification, for example, when the PTP data packet is encapsulated in an Internet Protocol (IP, Internet Protocol) V6 or IPV4 data stream. The access node may perform verification on the PTP data packet by using a user datagram protocol (UDP), an IP check, a CRC (Cyclical Redundancy Check), or the like. Determine if the PTP packet is correct. The implementation process of the specific check is a conventional implementation means of those skilled in the art, and details are not described herein again.

S203: The ingress network node sends the first update PTP data packet to the network.

Exemplarily, the network may cause the network to send the first updated PTP data packet to an outgoing node by using S203.

Exemplarily, since the first modified value is saved in the modified domain field of the first update PTP data packet, the first update PTP data packet includes time information of the data flow entering the transmission network; When the first updated PTP data packet arrives at the egress node of the transport network, the network dwell time of the transport network may be obtained by using the time information output by the first update PTP data packet from the transport network; Time to achieve time synchronization between device A and device B.

FIG. 4 is a method for time synchronization according to an embodiment of the present invention. The method can be applied to an egress node in a transmission network of the application scenario shown in FIG. 1. It can be understood that different network segments may appear correspondingly. The exit node, therefore, the exit node is a relative concept. The method can include:

S401: The outbound network node records a second time value of the outbound network node by the precise time protocol PTP data packet.

It should be noted that, in this embodiment, the PTP data packet is a PTP data packet that is received by the outbound network node from the network and sent by the network access node of the network; specifically, in this embodiment. In combination with the foregoing embodiment shown in FIG. 2, it can be known that the outgoing node is from the network. The PTP data packet received in the network is actually the first update PTP data packet sent by the network access node, and the correction value saved in the modified domain field of the first update PTP data packet is the first modified value.

Similar to the network access node of the embodiment shown in FIG. 2, the egress node can find the PTP data packet according to the feature field of the PTP data packet from the data stream sent by the network, and record the PTP data packet through the egress network. The second time value of the output end of the node, specifically, the second time value may be saved in the form of a network timestamp;

Preferably, the egress node may record the second time value at any one of the PTP data packets at the output end; preferably, in the embodiment of the present invention, the egress node may be in the PTP data packet from the The second time value is recorded when the output interface of the outlet node is close to the physical layer.

S402: The network node updates the correction value of the correction domain field in the PTP data packet according to the second time value, to obtain a second update PTP data packet.

Exemplarily, S402 may be specifically as shown in FIG. 5, and includes:

S4021: The egress node extracts a correction value of the correction domain field in the PTP data packet according to the format of the PTP data packet.

It can be understood that since the PTP data packet conforms to the IEEE1588 protocol and has a fixed data format, the outgoing node can extract the correction value from the modified domain field of the PTP data packet according to a fixed data format. The specific implementation manners are conventional implementation means of those skilled in the art, and are not described herein again.

However, in this embodiment, in combination with the embodiment shown in FIG. 2, since the PTP data packet is the first updated PTP data packet sent by the network access node, the PTP data packet is modified in the field field. The correction value is the first correction value.

S4022: The network node adds the correction value to the second time value to obtain the second correction value.

Specifically, in the embodiment, in combination with the embodiment shown in FIG. 2, since the correction value is The first correction value, therefore, the outlet node can obtain the correction value obtained by the S4021 and the second time value saved in the form of the outgoing network timestamp, to obtain the corrected value after the network node is updated. It can be understood that, since the first correction value includes the network access time information of the PTP data packet, the corrected value of the updated network node obtained after the first correction value plus the second time value includes the PTP data packet. The dwell time information of the entire transport network, which can be used for time synchronization between device B and device A.

In order to clarify the technical solution, in the present embodiment, the modified value of the outgoing node obtained by the outlet node through S4022 is referred to as a second correction value, which can be understood by those skilled in the art in the following description. Unless otherwise specified, the second correction value is used to indicate the correction value of the network node obtained by the network node through S4022 after updating.

S4023: The egress node updates the second correction value to the correction domain field according to the format of the PTP data packet.

Specifically, after obtaining the second correction value, the egress node may change the correction value in the correction domain field to the second correction value according to the format of the PTP data packet, thereby completing the update of the PTP data packet by the egress node. , thereby obtaining a second updated PTP data packet;

In this embodiment, in conjunction with the embodiment shown in FIG. 2, the egress node actually changes the first correction value in the first update PTP data packet to the second correction value, thereby obtaining the second update PTP data packet.

Exemplarily, between S401 and S402, the method may further include: the out network node checks the PTP data packet, and determines whether the PTP data packet is correct: when the PTP data packet is correct, continue to execute S402. When the PTP data packet is incorrect, end the current processing, for example, discarding the PTP data packet, and waiting for the arrival of the next PTP data packet;

Specifically, similar to the embodiment shown in FIG. 2, the egress node may adopt a corresponding verification technology according to different network layers in which the PTP data packet is located, and a format of a data flow encapsulating the PTP data packet. Perform verification; the specific embodiment has been detailed in the foregoing embodiment. Description, no longer repeat here.

It should be noted that, in combination with the application scenario shown in FIG. 1, when the second update PTP data packet is output from the outbound network node and then arrives at the device B, the device B may correct the second correction in the domain field by using the second update PTP data packet. The value of the time of the entire transmission network is obtained, and the time synchronization of the time synchronization is performed by the device A. The implementation process of the specific time synchronization is a conventional technical means of those skilled in the art, and details are not described herein again.

FIG. 6 is a schematic flowchart of a time synchronization method according to an embodiment of the present invention. The detailed process may be as follows:

S601: Device A sends a PTP data packet to the network access node.

Illustratively, in the application scenario shown in FIG. 1, the setting device A needs to perform time synchronization with the device B, and the transmission network 100 between the device A and the device B is represented by a dotted line frame area as shown in FIG. The network access node of the network is connected to device A, and the outbound network node of the transport network is connected to device B. Device A can encapsulate the PTP data packet in the data stream sent to the ingress network node.

S602: The ingress network node records a first time value of the PTP data packet entering the network access node.

Exemplarily, after the network access node receives the data stream sent by the device A, the PTP data packet may be searched from the data stream according to the feature field of the PTP data packet, and the PTP data packet is recorded to enter the first node of the network access node. The time value can be saved in the form of a network timestamp.

Preferably, the network access node may record the first time value at any one of the PTP data packets at the input end; preferably, in the embodiment of the present invention, the network access node may be in the PTP data packet from the network access node. The first time value is recorded when an input interface near the physical layer enters.

S603: The network access node checks the PTP data packet to determine whether the PTP data packet is correct.

Specifically, the network access node may be different according to the network layer where the PTP data packet is located. And the format of the data stream encapsulating the PTP data packet is different, and the corresponding verification technology may be used for verification, for example, when the PTP data packet is encapsulated in an Internet Protocol (IP, Internet Protocol) V6 or IPV4 data stream. The network access node may perform verification of the PTP data packet by using a User Datagram Protocol (UDP), IP check, or Cyclical Redundancy Check (CRC) check method. Determine if the PTP packet is correct. The implementation process of the specific check is a conventional implementation means of those skilled in the art, and details are not described herein again.

Specifically, when the PTP data packet is incorrect, the current processing ends, for example, discarding the PTP data packet, and waiting for the arrival of the next PTP data packet; when the PTP data packet is correct, proceeding to S604: accessing the network And the node updates the correction value of the correction domain field in the PTP data packet according to the first time value to obtain a first update PTP data packet;

Illustratively, the network access node updates the correction value of the modified domain field in the PTP data packet according to the first time value, which may be specifically shown in FIG. 3, and details are not described herein again.

S605: The ingress network node sends the first update PTP data packet to the network.

Exemplarily, the network may cause the network to send the first update PTP data packet to the egress node by using S605;

It should be noted that, because the first modified value is stored in the modified domain field of the first update PTP packet, the first updated PTP data packet includes time information of the data flow entering the transport network.

S606: The egress node receives the first update PTP data packet from the network.

Exemplarily, after the network node sends the first update PTP data packet to the network, the network node transmits the first update PTP data packet from the network.

S607: The outbound network node records, by the first update PTP data packet, a second time value of the outbound network node.

Similar to the incoming node, the outgoing node can receive the data stream from the network according to the PTP. The feature field of the data packet finds the first update PTP data packet, and records the second time value of the first update PTP data packet through the output end of the outgoing network node, and specifically saves the second time value in the form of the outgoing network time stamp;

Preferably, the egress node can record the second time value at any one of the first update PTP data packets at the output end; preferably, in the embodiment of the present invention, the egress network node can update the PTP data packet from the first The second time value is recorded when the output interface of the outlet node is close to the physical layer.

S608: The egress node checks the first update PTP data packet to determine whether the first update PTP data packet is correct.

Specifically, similar to S603, the egress node may perform different verification according to a different network layer where the first update PTP data packet is located, and a format of the data flow encapsulating the first updated PTP data packet, and may be verified by using a corresponding verification technology; The specific implementation is described in detail in S603, and details are not described herein again.

Specifically, when the PTP data packet is incorrect, the current processing ends, for example, discarding the PTP data packet, and waiting for the arrival of the next PTP data packet; when the PTP data packet is correct, proceeding to S609: And the network node updates, according to the second time value, a correction value of the correction domain field in the first update PTP data packet, to obtain a second update PTP data packet;

Exemplarily, the specific implementation process of S609 can be as shown in FIG. 5, and details are not described herein again.

S610: The egress node transmits the second update PTP data packet to the device B.

Exemplarily, the device B may obtain the dwell time of the entire transmission network by using the second correction value in the second update PTP packet correction domain field, and may perform time synchronization with the device A through the dwell time, and the specific time synchronization The implementation process is a conventional technical means for those skilled in the art and will not be described herein.

The detailed process of the method for time synchronization provided by this embodiment only calculates the dwell time of the transport network by the network access node and the egress node of the transport network, so that no transmission is needed. Each node in the network calculates its own dwell time, reduces the resource overhead in the transport network, and does not accumulate the computational errors caused by each node in the transport network calculating its own dwell time. The calculation accuracy of the dwell time of the transmission network; it is even more unnecessary to consider the asymmetry of the bidirectional transmission path of the transmission medium between each node in the transmission network, thereby reducing the workload of the network.

FIG. 7 is a schematic structural diagram of a network access node 70 according to an embodiment of the present invention. As shown in FIG. 7, the network access node 70 may include: a first recording unit 701, a first updating unit 702, and a sending unit 703, where

The first recording unit 701 is configured to record a first time value of the precise time protocol PTP data packet entering the network access node 70;

The first update unit 702 is configured to update the correction value of the correction domain field in the PTP data packet according to the first time value obtained by the first recording unit 701, to obtain a first update PTP data packet;

The sending unit 703 is configured to send the first updated PTP data packet to the network, so that the network sends the first updated PTP data packet to an outgoing node.

Exemplarily, the embodiment may be described in conjunction with the scenario shown in FIG. 1. The first recording unit 701 may find the PTP data packet from the data field sent by the device A according to the feature field of the PTP data packet, and may record The PTP data packet enters a first time value of the network access node. Specifically, the first recording unit 701 may save the first time value in the form of a network timestamp;

Preferably, the first recording unit 701 can record the first time value at any one of the input ends of the PTP data packet; preferably, in the embodiment of the present invention, the first recording unit 701 can The first time value is recorded when the PTP data packet enters from the input interface of the access node 70 near the physical layer.

Illustratively, as shown in FIG. 8, the first update unit 702 may include: a first extraction module 7021, a first calculation module 7022, and a first update module 7023, where

The first extraction module 7021 is configured to extract a correction value of the correction domain field in the PTP data packet according to the format of the PTP data packet;

It can be understood that since the PTP data packet conforms to the IEEE1588 protocol and has a fixed data format, the first extraction module 7021 can extract the correction value from the correction domain field of the PTP data packet according to a fixed data format. The specific implementation method is a conventional implementation means of a person skilled in the art, and details are not described herein again;

The first calculating module 7022 is configured to subtract the first time value from the correction value to obtain a first correction value;

Specifically, in the embodiment, the first calculating module 7022 can obtain the first time value saved by the first extraction module 7021 minus the time stamp in the network, so that the updated value of the network node 70 after updating can be obtained. In order to clearly explain the technical solution, in the present embodiment, the updated value of the network access node obtained by the first calculation module 7022 is referred to as a first correction value, and those skilled in the art can understand that, in the following description, Unless otherwise specified, the correction value after the update of the network access node obtained by the first calculation module 7022 is represented by the first correction value;

The first update module 7023 is configured to update the first correction value to the correction domain field according to a format of the PTP data packet;

Specifically, after the first calculation module 7022 obtains the first correction value, the first update module 7023 may change the original correction value in the correction domain field to the first correction value according to the format of the PTP data packet, thus completing the first An update unit 702 updates the PTP data packet to obtain a first update PTP data packet.

For example, referring to FIG. 8, the network access node 70 may further include a first check unit 704 configured to check the PTP data packet, determine whether the PTP data packet is correct, and determine that the PTP data packet is correct. And triggering, by the first update unit 702, processing of the PTP data packet; when determining that the PTP data packet is incorrect, triggering end processing, for example, discarding the PTP data packet, and waiting for the next PTP data packet Coming

Specifically, the first check unit 704 may be configured according to different network layers in which the PTP data packet is located, and a format of a data flow encapsulating the PTP data packet, and may be verified by using a corresponding verification technology, for example, When the PTP data packet is encapsulated in an Internet Protocol (IP) V6 or IPV4 data stream, the first check unit 704 may use a User Datagram Protocol (UDP) check, an IP check, and a loop. A verification method such as a CRC (Cyclical Redundancy Check) checks the PTP data packet to determine whether the PTP data packet is correct. The implementation process of the specific check is a conventional implementation means of those skilled in the art, and details are not described herein again.

It should be noted that, since the first modified value is stored in the modified domain field of the first updated PTP data packet, the first updated PTP data packet includes time information of the data flow entering the transmission network; And when the first update PTP data packet arrives at the egress node of the transport network, the network camp time of the transport network may be obtained by using the time information output by the first update PTP data packet from the transport network; Allow time to implement time synchronization between device A and device B.

FIG. 9 is a schematic structural diagram of an egress node 90 according to an embodiment of the present invention. As shown in FIG. 9, the egress node 90 may include: a second recording unit 901 and a second update unit 902, where

The second recording unit 901 is configured to record a second time value of the precise time protocol PTP data packet output network node 90; the PTP data packet is received by the outbound network node 90 from the network, and is connected to the network node of the network. PTP packet sent;

The second update unit 902 is configured to update the correction value of the correction domain field in the PTP data packet according to the second time value to obtain a second update PTP data packet.

Exemplarily, in this embodiment, in combination with the foregoing embodiment shown in FIG. 2, it can be known that the PTP data packet received by the egress node 90 from the network is actually the first update PTP data packet sent by the ingress network node, where Correction saved in the modified domain field of the first update PTP packet The value is the first correction value.

Similar to the network access node of the embodiment shown in FIG. 2, the second recording unit 901 can find the PTP data packet according to the feature field of the PTP data packet from the data stream sent by the network, and record the PTP data packet. The second time value of the output end of the outbound network node 90, specifically, the second time value may be saved in the form of a network timestamp;

Preferably, the second recording unit 901 can record the second time value at any one of the PTP data packets at the output end of the outlet node 90. Preferably, in the embodiment of the present invention, the second recording unit 901 can be The second time value is recorded when the PTP data packet is output from the output interface of the outgoing node 90 near the physical layer.

Illustratively, as shown in FIG. 10, the second update unit 902 may include: a second extraction module 9021, a second calculation module 9022, and a second update module 9023, where

The second extraction module 9021 is configured to extract a correction value of the correction domain field in the PTP data packet according to the format of the PTP data packet;

It can be understood that since the PTP data packet conforms to the IEEE1588 protocol and has a fixed data format, the second extraction module 9021 can extract the correction value from the correction domain field of the PTP data packet according to a fixed data format. The specific implementation method is a conventional implementation means of those skilled in the art, and details are not described herein again.

However, in this embodiment, in combination with the embodiment shown in FIG. 8, since the PTP data packet is the first updated PTP data packet sent by the network access node, the PTP data packet is modified in the field field. The correction value is the first correction value.

The second calculation module 9022 is configured to add the correction value to the second time value to obtain the second correction value;

Specifically, in this embodiment, in combination with the embodiment shown in FIG. 8, since the correction value is the first correction value, the second calculation module 9022 can add the correction value obtained by the second extraction module 9021. The second time value saved in the form of the outgoing timestamp, to obtain the outgoing node 90 The new correction value. It can be understood that, since the first correction value includes the network access time information of the PTP data packet, the corrected value of the updated network node obtained after the first correction value plus the second time value includes the PTP data packet. The dwell time information of the entire transport network, which can be used for time synchronization between device B and device A.

In order to clearly explain the technical solution, in the present embodiment, the updated value of the network node obtained by the second calculation module 9022 is referred to as a second correction value, which can be understood by those skilled in the art in the following description. Unless otherwise specified, the correction value after the update of the outlet node obtained by the second calculation module 9022 is represented by the second correction value.

The second update module 9023 is configured to update the second correction value to the correction domain field according to the format of the PTP data packet;

Specifically, after obtaining the second correction value, the second update module 9023 may change the correction value in the correction domain field to the second correction value according to the format of the PTP data packet, thus completing the outbound network node to the PTP data packet. Update to get the second update PTP packet;

In this embodiment, in conjunction with the embodiment shown in FIG. 7, the second update unit 902 actually changes the first correction value in the first update PTP data packet to the second correction value, thereby obtaining the second update PTP data. package.

For example, referring to FIG. 10, the egress node 90 may further include a second check unit 903 configured to check the PTP data packet to determine whether the PTP data packet is correct, when determining the PTP data packet. When correct, triggering the processing of the PTP data packet by the second updating unit 902; when it is determined that the PTP data packet is incorrect, triggering the end processing, for example, discarding the PTP data packet, and waiting for the arrival of the next PTP data packet ;

Specifically, similar to the first check unit in the embodiment shown in FIG. 8, the second check unit 903 may be different according to a network layer in which the PTP data packet is located, and a format of a data stream encapsulating the PTP data packet. The verification is performed by using the corresponding verification technology. The specific implementations are described in detail in the foregoing embodiments, and details are not described herein again.

It should be noted that, in combination with the application scenario shown in FIG. 1, when the second update PTP data packet is output from the outbound network node and then arrives at the device B, the device B may correct the second correction in the domain field by using the second update PTP data packet. The value of the time of the entire transmission network is obtained, and the time synchronization of the time synchronization is performed by the device A. The implementation process of the specific time synchronization is a conventional technical means of those skilled in the art, and details are not described herein again.

FIG. 11 is a schematic structural diagram of hardware of a network access node 70 according to an embodiment of the present invention. The network access node 70 may include at least one communication interface 1101, a processor 1102, a memory 1103, and a bus 1104: the at least one communication interface 1101 processes The memory 1102 and the memory 1103 are connected by a bus 1104 and complete communication with each other.

The bus 1104 may be an Industrial Standard Architecture (ISA) bus, a Peripheral Component (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. The bus 1104 can be divided into an address bus, a data bus, a control bus, and the like. For ease of representation, only one thick line is shown in Figure 11, but it does not mean that there is only one bus or one type of bus. among them:

The memory 1103 is configured to store executable program code, the program code including computer operating instructions. The memory 1103 may include a high speed RAM memory and may also include a non-volatile memory such as at least one disk memory. Stored in the storage device: an operating system, an application, and a program code configured to implement the embodiments of the present invention. The operating system is configured to control and implement the processing functions performed by the processing unit. The application contains program code, such as word processing software, email software.

The processor 1102 may be a Central Processing Unit (CPU), or an Application Specific Integrated Circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present invention.

a communication interface 1101 configured to communicate with an external device;

The processor 1102 is configured to record a first time value of the precise time protocol PTP data packet entering the network access node;

And updating, according to the first time value obtained by the first recording unit, a correction value of the correction domain field in the PTP data packet, to obtain a first update PTP data packet;

And transmitting, by the communication interface 1101, the first updated PTP data packet to the network, so that the network sends the first updated PTP data packet to an outgoing node.

Illustratively, the processor 1102 is further configured to extract a correction value of the correction domain field in the PTP data packet according to the format of the PTP data packet;

And subtracting the correction value from the first time value to obtain a first correction value;

And updating the first correction value to the correction domain field according to a format of the PTP data packet.

Illustratively, the processor 1102 is further configured to record the first time value as the PTP data packet enters from an incoming interface of the physical layer adjacent to the physical layer.

Illustratively, the processor 1102 is further configured to verify the PTP data packet to determine if the PTP data packet is correct.

FIG. 12 is a schematic diagram showing the hardware structure of an outgoing node 90 according to an embodiment of the present invention. The outgoing node 90 includes at least one communication interface 1201, a processor 1202, a memory 1203, and a bus 1204: the at least one communication interface 1201 The processor 1202 and the memory 1203 are connected by the bus 1204 and complete communication with each other.

The bus 1204 may be an Industrial Standard Architecture (ISA) bus, a Peripheral Component (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. The bus 1204 can be divided into an address bus, a data bus, a control bus, and the like. For ease of representation, only one thick line is shown in Figure 12, but it does not mean that there is only one bus or one type of bus. among them:

The memory 1203 is configured to store executable program code, the program code including computer operating instructions. The memory 1203 may include a high speed RAM memory and may also include a non-volatile memory such as at least one disk memory. Stored in the storage device: an operating system, an application, and a program code configured to implement the embodiments of the present invention. The operating system is configured to control and implement the processing functions performed by the processing unit. The application contains program code, such as word processing software, email software.

The processor 1202 may be a Central Processing Unit (CPU), or an Application Specific Integrated Circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present invention.

a communication interface 1201 configured to communicate with an external device;

The processor 1202 is configured to record a second time value of the outbound network node by using a precise time protocol PTP data packet; the PTP data packet is received by the outbound network node from the network, and is connected to the network by the network node PTP packet sent;

And updating, according to the second time value, a correction value of the correction domain field in the PTP data packet to obtain a second update PTP data packet.

Illustratively, processor 1202 is further configured to:

Extracting a correction value of the correction domain field in the PTP data packet according to the format of the PTP data packet;

And adding the correction value to the second time value to obtain the second correction value;

And updating the second correction value to the correction domain field according to a format of the PTP data packet.

Illustratively, the processor 1202 is further configured to: record the second time value when the PTP data packet is output from an output interface of the outgoing node adjacent to the physical layer.

Illustratively, the processor 1202 is further configured to verify the PTP data packet to determine if the PTP data packet is correct.

Referring to FIG. 13, a time synchronization system according to an embodiment of the present invention may be used. Including the network access node 70 and the outgoing network node 90, wherein

The network access node 70 is configured to record a first time value of the precise time protocol PTP data packet entering the network access node, and update a correction value of the modified domain field in the PTP data packet according to the first time value to obtain a first update PTP. Transmitting the first update PTP data packet to the network, so that the network sends the first update PTP data packet to an outgoing network node; the specific implementation process is as described in the foregoing embodiment, This will not be repeated here;

The outbound node 90 is configured to record a second time value of the first update PTP data packet outputting the outbound network node, and to update a correction domain field in the first update PTP data packet according to the second time value The value is obtained, and the second update PTP data packet is obtained; the specific implementation process is as described in the foregoing embodiment, and details are not described herein again.

Illustratively, the ingress network node 70 is further configured to verify the PTP data packet, and when the PTP data packet is determined to be incorrect, terminate the current process.

Exemplarily, the outbound node 90 is further configured to check the first updated PTP data packet to determine that the first update PTP data packet is incorrect, and end the current process.

The embodiment of the invention also describes a time synchronization system, which calculates the dwell time of the transmission network only through the ingress node 70 and the outbound node 90 of the transmission network, so that no node in the transmission network needs to be transmitted. To calculate the respective dwell time, reduce the resource overhead in the transmission network; and it does not accumulate the calculation error caused by calculating the respective dwell time of each node in the transmission network, and improves the dwell time of the transmission network. The calculation accuracy is not necessary to consider the asymmetry of the two-way transmission path of the transmission medium between each node in the transmission network, thereby reducing the workload of the network.

Embodiments of the present invention also describe a storage medium in which a computer program is stored, the computer program being configured to perform the method of time synchronization of the foregoing embodiments.

Those skilled in the art will appreciate that embodiments of the present invention can be provided as a method, system, or computer program product. Accordingly, the present invention may employ hardware embodiments, software embodiments, or junctions. In the form of an embodiment of the software and hardware aspects. Moreover, the invention can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) including computer usable program code.

The present invention has been described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (system), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flowchart illustrations and/or FIG. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing device to produce a machine for the execution of instructions for execution by a processor of a computer or other programmable data processing device. Means for implementing the functions specified in one or more of the flow or in a block or blocks of the flow chart.

The computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture comprising the instruction device. The apparatus implements the functions specified in one or more blocks of a flow or a flow and/or block diagram of the flowchart.

These computer program instructions can also be loaded onto a computer or other programmable data processing device such that a series of operational steps are performed on a computer or other programmable device to produce computer-implemented processing for execution on a computer or other programmable device. The instructions provide steps for implementing the functions specified in one or more of the flow or in a block or blocks of a flow diagram.

It is to be understood that the term "comprises", "comprising", or any other variants thereof, is intended to encompass a non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes those elements. It also includes other elements that are not explicitly listed, or elements that are inherent to such a process, method, article, or device. In the absence of more restrictions, the elements defined by the statement "including one..." are not excluded from inclusion. There are additional identical elements in the process, method, item or device of the element.

The above is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

Industrial applicability

The invention calculates the dwell time of the transmission network by the network access node and the egress node of the transmission network, so that each node in the transmission network is not required to calculate the respective dwell time, and the resource overhead in the transmission network is reduced; Moreover, the calculation error caused by calculating the respective dwell time of each node in the transmission network is not accumulated, and the calculation precision of the residence time of the transmission network is improved; and the transmission medium between each node in the transmission network is not required to be considered. The asymmetry of the two-way transmission path reduces the workload of the network.

Claims (20)

1. A method of time synchronization, including:

   The network access node records the first time value of the precise time protocol PTP data packet entering the network access node;

   Updating, by the network access node, a correction value of the modified domain field in the PTP data packet according to the first time value, to obtain a first updated PTP data packet;

   The network access node sends the first updated PTP data packet to a network, so that the network sends the first updated PTP data packet to an outgoing network node.
2. The method according to claim 1, wherein the network access node updates the correction value of the correction domain field in the PTP data packet according to the first time value, including:

   The network access node extracts a correction value of the correction domain field in the PTP data packet according to the format of the PTP data packet;

   The network access node subtracts the correction value from the first time value to obtain a first correction value;

   The network access node updates the first correction value to the correction domain field according to a format of the PTP data packet.
3. The method of claim 1, wherein the network access node records a first time value of the PTP data packet entering the network access node, including:

   The network access node records the first time value when the PTP data packet enters from an input interface of the network access node that is close to the physical layer.
4. The method according to any one of claims 1 to 3, wherein after the network node records the first time value of the PTP data packet entering the network access node, and at the network access node according to the first Before the time value updates the correction value of the correction domain field in the PTP data packet, the method further includes:

   The network access node checks the PTP data packet to determine that the PTP data packet is incorrect, and ends the current processing.
5. A method of time synchronization, including:

   The outbound network node records the precise time protocol PTP data packet to output the second time value of the outgoing network node; the PTP data packet is received by the outgoing network node from the network, and is sent by the network access node in the network;

   And the egress node updates the correction value of the correction domain field in the PTP data packet according to the second time value to obtain a second update PTP data packet.
6. The method according to claim 5, wherein the outgoing node updates the correction value of the correction domain field in the PTP data packet according to the second time value, including:

   And the egress node extracts a correction value of the correction domain field in the PTP data packet according to the format of the PTP data packet;

   And the outgoing node adds the correction value to the second time value to obtain the second correction value;

   The egress node updates the second correction value to the correction domain field according to a format of the PTP data packet.
7. The method of claim 5, wherein the outbound node records the second time value of the PTP data packet outputting the outbound network node, including:

   The egress node records the second time value when the PTP data packet is output from an output interface of the egress node near the physical layer.
8. The method according to any one of claims 5 to 7, wherein after the egress node records the second time value of the PTP data packet outputting the egress node, and at the egress node according to the Before the second time value updates the correction value of the correction domain field in the PTP data packet, the method further includes:

   The outgoing node checks the PTP data packet to determine that the PTP data packet is incorrect, and ends the current processing.
9. An access node includes: a first recording unit, a first update unit, and a sending unit, among them,

   The first recording unit is configured to record a first time value of the precise time protocol PTP data packet entering the network access node;

   The first update unit is configured to update a correction value of the correction domain field in the PTP data packet according to the first time value obtained by the first recording unit, to obtain a first update PTP data packet;

   The sending unit is configured to send the first updated PTP data packet to a network, so that the network sends the first updated PTP data packet to an outgoing node.
10. The network access node according to claim 9, wherein the first update unit comprises: a first extraction module, a first calculation module, and a first update module, where

    The first extraction module is configured to extract a correction value of the correction domain field in the PTP data packet according to the format of the PTP data packet;

    The first calculating module is configured to subtract the first time value from the correction value to obtain a first correction value;

    The first update module is configured to update the first correction value to the correction domain field in accordance with a format of the PTP data packet.
11. The network access node according to claim 9, wherein the first recording unit is configured to record the first time value when the PTP data packet enters from an input interface of the network access node close to the physical layer.
12. The network access node according to any one of claims 9 to 11, wherein the network access node further comprises a first check unit configured to check the PTP data packet to determine that the PTP data packet is incorrect , trigger end processing.
13. An outgoing node includes: a second recording unit and a second updating unit, wherein

    The second recording unit is configured to: record a precise time protocol PTP data packet to output a second time value of the outgoing network node; the PTP data packet is received by the outgoing network node from the network, and the network is received by the network The network node sends;

    The second update unit is configured to update the correction value of the correction domain field in the PTP data packet according to the second time value to obtain a second update PTP data packet.
14. The network outlet node according to claim 13, wherein the second update unit comprises: a second extraction module, a second calculation module, and a second update module, where

    The second extraction module is configured to extract a correction value of the correction domain field in the PTP data packet according to the format of the PTP data packet;

    The second calculating module is configured to add the correction value to the second time value to obtain the second correction value;

    The second update module is configured to update the second correction value to the correction domain field in accordance with a format of the PTP data packet.
15. The outgoing node according to claim 13, wherein the second recording unit is further configured to record the second time when the PTP data packet is output from an output interface of the outgoing node close to the physical layer value.
16. The egress node according to any one of claims 13 to 15, wherein the egress node further comprises: a second check unit configured to check the PTP data packet to determine the PTP data packet When it is incorrect, the trigger ends processing.
17. A time synchronization system, including an ingress node and an egress node, wherein

    The network access node is configured to record a first time value of the precise time protocol PTP data packet entering the network access node, and update a correction value of the modified domain field in the PTP data packet according to the first time value to obtain a first update. a PTP data packet; sending the first update PTP data packet to the network, so that the network sends the first update PTP data packet to an outgoing node;

    The egress node is configured to record a second time value of the first update PTP data packet outputting the egress node, and update a correction domain field in the first update PTP data packet according to the second time value Correct the value to get the second update PTP packet.
18. The system of claim 17 wherein said network access node is further configured to be When the PTP data packet is checked and it is determined that the PTP data packet is incorrect, the current processing ends.
19. The system of claim 17, wherein the outgoing node is further configured to verify the first updated PTP packet and determine that the first updated PTP packet is incorrect, ending the current process.
20. A storage medium having stored therein a computer program configured to perform the method of time synchronization according to any one of claims 1 to 4 or any of claims 5 to 8.

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