WO2023231864A1

WO2023231864A1 - Timeliness guarantee method, apparatus and system

Info

Publication number: WO2023231864A1
Application number: PCT/CN2023/096053
Authority: WO
Inventors: 王元发; 石帅; 姚松平; 代贝; 郑文文; 吴正
Original assignee: 华为技术有限公司
Priority date: 2022-05-28
Filing date: 2023-05-24
Publication date: 2023-12-07
Also published as: CN117200921A

Abstract

Embodiments of the present application provide a timeliness guarantee method, apparatus and system, applied to the communication technology. The method comprises: a network device receiving a data frame, the data frame comprising timeliness information; obtaining a transmission delay on the basis of a start moment of a link layer of the network device receiving the data frame and a termination moment of the link layer receiving the data frame; obtaining an overall forwarding delay on the basis of the time required by a protocol stack or an application layer of the network device to process the data frame; updating the timeliness information on the basis of the transmission delay and the overall forwarding delay; and sending the updated data frame. According to the present application, the network device and/or a receiving terminal can update the timeliness information of the data frame, such that the receiving terminal can determine whether the data frame is valid or not on the basis of the updated timeliness information. The method does not need to keep the time synchronization of a sending terminal, the receiving terminal, and the network device.

Description

A timeliness guarantee method, device and system

This application claims priority to the Chinese patent application submitted to the China Patent Office on May 28, 2022, with the application number 202210592686.2 and the application title "A timeliness guarantee method, device and system", the entire content of which is incorporated herein by reference. Applying.

Technical field

This application relates to the field of communication technology, and specifically to a timeliness guarantee method, device and system.

Background technique

In the industrial Ethernet environment, in order to ensure the stable operation of industrial production, there are certain requirements for the timeliness of query and control instructions.

The existing technical solution requires the deployment of a high-precision clock server in the industrial Ethernet. The requester and responder ensure that the system time of both parties is consistent with the time of the high-precision clock server through a clock synchronization algorithm. The requester adds timestamp information in the query and control instructions. , the responder can determine whether the instruction needs to be executed based on the timestamp and system time in the instruction, where the requester can be the controller and the responder can be the executor (Actuator). In this method, a high-precision time synchronization server needs to be deployed within the network, and there is a deployment cost.

Contents of the invention

The embodiments of this application disclose a timeliness guarantee method, device and system. Through this application, the network device and/or the receiving end can update the timeliness information of the data frame, so that the receiving end can determine whether the data frame is valid based on the updated timeliness information. This method does not need to keep the time of the sending end, the receiving end and the network device. Synchronization can reduce the deployment cost of deploying time synchronization server.

In the first aspect, embodiments of the present application disclose a timeliness guarantee method, which is applied to network equipment. The method includes:

Receive a data frame, the data frame includes aging information, and the aging information is used to indicate the remaining aging of the data frame;

Based on the start time of the network device's link layer receiving the data frame and the end time of the link layer receiving the data frame, the transmission delay is obtained;

Based on the time required for the protocol stack or application layer of the network device to process the data frame, the overall forwarding delay is obtained;

Update aging information based on transmission delay and overall forwarding delay;

Send updated data frame.

Through this application, the sending end can send a data frame carrying aging information, and the network device and the receiving end can update the aging information of the data frame, so that the receiving end can determine whether the data frame is valid based on the updated aging information. This method does not need to keep sending. By synchronizing the time of the end, receiving end and network equipment, you can determine whether the data frame is within the time limit. This method can reduce the deployment cost of deploying a time synchronization server.

Combined with the first aspect, in a possible implementation, the transmission delay is the time difference between the start time and the end time; the start time is the time when the start bit of the data frame is received, and the end time is the time when the data frame is received. The moment of the end position;

The remaining aging in the updated data frame is the remaining aging in the data frame minus the difference between the transmission delay and the overall forwarding delay.

Combined with the first aspect, in a possible implementation, the overall forwarding delay includes a receiving processing delay and a sending processing delay; based on the transmission delay and the overall forwarding delay, updating the aging information includes:

Update the remaining aging of the data frame to the first aging to obtain the first data frame; the first aging is the remaining aging of the data frame minus the difference between the transmission delay and the reception processing delay; the reception processing delay is the link layer reception The time required for the protocol stack or application layer to receive and process the data frame after the data frame; the remaining aging of the first data frame is the first aging;

Update the remaining aging of the first data frame to the second aging to obtain the updated data frame; the second aging is the difference between the first aging and the transmission processing delay, and the transmission processing delay is the link layer sending the updated data The pre-frame protocol stack or application layer sends the time required to process the first data frame; the remaining aging of the updated data frame is the second aging.

Combined with the first aspect, in a possible implementation, before sending the updated data frame, the method further includes:

Based on the first timeliness, a processing method for the first data frame is determined; the processing method includes priority forwarding, normal forwarding, or discarding.

In this embodiment of the present application, the network device can also make a forwarding decision based on the first timeliness, thereby determining whether to forward the data frame preferentially, forward it normally, or discard the data frame. In this method, invalid data frames can be avoided and forwarding efficiency can be accelerated; it can also avoid transmission of invalid data frames, causing a waste of network resources.

In conjunction with the first aspect, in a possible implementation, based on the first timeliness, determining a processing method for the first data frame includes:

Based on at least one of the reliability level corresponding to the data frame and the real-time level corresponding to the data frame and the first timeliness, a processing method for the first data frame is determined.

In this embodiment of the present application, the network device may determine whether to preferentially forward the data frame based on the reliability level corresponding to the data frame and the real-time level corresponding to the data frame. With this method, important messages can be forwarded with priority.

In conjunction with the first aspect, in a possible implementation, the data frame carries any one of a request message, a response message, and an active notification message. The request message includes a query instruction or a control instruction, and the response message is in response to the query instruction or control instruction. The reply message generated by the command.

In conjunction with the first aspect, in a possible implementation, the data frame carries a response message generated by the responder in response to the query instruction of the first requester, and the method further includes:

Store the response message.

In a possible implementation, the network device stores the parsed message content of the data frame.

In this embodiment of the present application, the network device can also store the received response message, so that when other requesting parties request the response message, the network device can send the response message to other requesting parties. This method can achieve nearby response and improve response efficiency.

Combined with the first aspect, in a possible implementation, after updating the remaining timeliness of the data frame to the first timeliness and obtaining the first data frame, the response message is stored, including:

When the first timeliness and the real-time level corresponding to the response message satisfy the cache decision, the response message is stored.

In this embodiment of the present application, the network device can only store data frames without invalidation to avoid wasting storage space.

Combined with the first aspect, in a possible implementation, the method further includes:

Receive a query instruction from the second requester, and the query instruction from the second requester is used to request a response message;

Send a response message to the second requester.

Combined with the first aspect, in a possible implementation, sending a response message to the second requester includes:

Obtain the first aging corresponding to the response message and the time when the response message is stored;

When the time difference between the current time and the time when the response message is stored is not greater than the first aging, send the response message to the second requester;

When the time difference between the current time and the time when the response message is stored is greater than the first aging, the request message is sent to the responder.

In this embodiment of the present application, the network device may send the data frame to other requesters after determining that the data frame is not invalid. This method avoids sending invalid data frames to other requesters.

In the second aspect, embodiments of the present application disclose a timeliness guarantee method, which is applied to the sending end. The method includes:

The sending end sends a data frame to the receiving end; the data frame includes aging information, and the aging information of the data frame is used to indicate the remaining aging of the data frame;

The receiving end is used to update the remaining aging of the data frame based on the link delay and the reception processing delay; the link delay is obtained based on the starting time of the receiving end's link layer receiving the data frame and the end time of the link layer receiving the data frame. ; the reception processing delay is the time required for the protocol stack or application layer to receive and process the data frame after the link layer receives the data frame.

In the third aspect, embodiments of the present application disclose a timeliness guarantee method, which is applied to the receiving end. The method includes:

The receiving end receives the data frame from the sending end; the data frame includes aging information, and the aging information of the data frame is used to indicate the remaining aging of the data frame;

The receiving end obtains the link delay based on the starting time when the receiving end's link layer receives the data frame and the ending time when the receiving end's link layer receives the data frame;

Based on the link delay and the reception processing delay, the remaining aging is updated; the reception processing delay is the time required for the protocol stack or application layer to receive and process the data frame after the link layer receives the data frame.

Through this application, the sending end can send a data frame carrying aging information, and the data end can update the aging information of the data frame, so that the receiving end can determine whether the data frame is valid based on the updated aging information. This method does not require keeping the sending end and the receiving end. End-to-end time synchronization can reduce the deployment cost of deploying a time synchronization server.

Combined with the third aspect, in a possible implementation, the data frame carries a request message, and the request message includes a query instruction or a control instruction; the method further includes:

When the receiving end determines that the request message is valid based on the remaining aging and the preset threshold, it executes the query instruction or the control instruction.

Combined with the third aspect, in a possible implementation, the receiving end receives a data frame from the sending end, including:

The receiving end receives the data frame from the requesting party via at least one network device;

At least one network device is used to update the remaining aging of the data frame based on the transmission delay and the overall forwarding delay; the transmission delay is based on the starting time of the link layer of the network device receiving the data frame and the link layer of the network device receiving the data frame. The termination time is obtained; the overall forwarding delay is obtained based on the time required for the protocol stack or application layer of the network device to process the data frame.

In the fourth aspect, this application provides an aging guarantee device, which includes:

a receiving unit, configured to receive a data frame, the data frame includes aging information, and the aging information is used to indicate the remaining aging of the data frame;

The first processing unit is used to obtain the transmission delay based on the start time of the link layer receiving the data frame and the end time of the link layer receiving the data frame based on the network device;

The second processing unit is used to obtain the overall forwarding delay based on the time required for the protocol stack or application layer of the network device to process the data frame;

The update unit is used to update the aging information based on the transmission delay and the overall forwarding delay;

The sending unit is used to send the updated data frame.

Combined with the fourth aspect, in a possible implementation, the transmission delay is the time difference between the start time and the end time; the start time is the time when the start bit of the data frame is received, and the end time is the time when the data frame is received. The moment of the end position;

Combined with the fourth aspect, in a possible implementation, the overall forwarding delay includes receiving processing delay and sending processing delay. Latency; update unit is used for:

Combined with the fourth aspect, in a possible implementation, before the sending unit sends the updated data frame, the device further includes a processing unit, and the processing unit is configured to:

Combined with the fourth aspect, in a possible implementation, the processing unit is used to:

In conjunction with the fourth aspect, in a possible implementation, the data frame carries any one of a request message, a response message and an active notification message. The request message includes a query instruction or a control instruction, and the response message is in response to the query instruction or control instruction. The reply message generated by the command.

In conjunction with the fourth aspect, in a possible implementation, the data frame carries a response message generated by the responder in response to the query instruction of the first requester, and the device further includes a storage unit, and the storage unit is used for:

Store the response message.

Combined with the fourth aspect, in a possible implementation, the storage unit is used for:

In conjunction with the fourth aspect, in a possible implementation, the receiving unit is configured to receive a query instruction from the second requester, and the query instruction from the second requester is used to request a response message;

A sending unit, configured to send a response message to the second requester.

Combined with the fourth aspect, in a possible implementation, the sending unit is used for:

In the fifth aspect, embodiments of the present application provide an aging guarantee device, which includes:

The receiving unit is used to receive the data frame from the sending end; the data frame includes aging information, and the aging information of the data frame is used to indicate the remaining aging of the data frame;

A processing unit configured to obtain the link delay based on the starting time when the link layer at the receiving end receives the data frame and the end time when the link layer at the receiving end receives the data frame;

The update unit is used to update the remaining aging based on the link delay and the reception processing delay; the reception processing delay is the time required for the protocol stack or the application layer to receive and process the data frame after the link layer receives the data frame.

In conjunction with the fifth aspect, in a possible implementation, the data frame carries a request message, and the request message includes a query instruction or a control instruction; the device further includes an execution unit, and the execution unit is used to:

When it is determined that the request message is valid based on the remaining aging and the preset threshold, the query instruction or the control instruction is executed.

Combined with the fifth aspect, in a possible implementation, the receiving unit is used for:

receiving data frames from the requesting party via at least one network device;

In a sixth aspect, embodiments of the present application disclose a timeliness guarantee device, which includes a processor and a communication interface. The processor is configured to call a computer program stored in a memory to implement the first aspect or any possibility of the first aspect. The method described in the implementation.

In a seventh aspect, embodiments of the present application disclose a timeliness guarantee device, which includes a processor and a communication interface. The processor is configured to call a computer program stored in a memory to implement the second aspect or any possibility of the second aspect. way of implementation.

In an eighth aspect, embodiments of the present application disclose a timeliness guarantee device, which includes a processor and a communication interface. The processor is configured to call a computer program stored in a memory to implement the third aspect or any possibility of the third aspect. way of implementation.

In a ninth aspect, embodiments of the present application further provide a chip system. The chip system includes at least one processor and a communication interface. The communication interface is used to send and/or receive data. The at least one processor is used to call at least A computer program stored in a memory, so that the device where the chip system is located implements the first aspect or the method described in any possible implementation of the first aspect; or implements the second aspect or any of the second aspects The method described in one possible implementation manner; or the method described in any possible implementation manner of implementing the third aspect or the third aspect.

In a tenth aspect, embodiments of the present application further provide a communication system, including a receiving end, a network device, and a sending end. Wherein, the network device is used to implement the method described in the first aspect or any possible implementation manner of the first aspect; and the sending end implements the method described in the first aspect or any possible implementation manner of the first aspect. The described method; the receiving end is used to implement the method described in the first aspect or any possible implementation manner of the first aspect.

In an eleventh aspect, embodiments of the present application disclose a computer-readable storage medium. A computer program is stored in the computer-readable storage medium. When the computer program is run on one or more processors, the first step is executed. The method described in one aspect or any possible implementation of the first aspect, or the method described in the second aspect or any possible implementation of the second aspect, or the implementation of the third aspect or the method described in any possible implementation of the second aspect. The method described in any possible implementation manner of the three aspects.

In a twelfth aspect, the embodiment of the present application discloses a computer program product. When the computer program product is run on one or more processors, it executes the first aspect or any possible implementation manner of the first aspect. The described method, or perform the second aspect or the method described in any possible implementation manner of the second aspect; or implement the third aspect or the method described in any possible implementation manner of the third aspect .

Description of the drawings

The drawings used in the embodiments of this application are introduced below.

Figure 1 is a schematic diagram of a method for ensuring message timeliness in the prior art provided by an embodiment of the present application;

Figure 2A is a schematic diagram of a possible communication system provided by an embodiment of the present application;

Figure 2B is a schematic diagram of another possible communication system provided by an embodiment of the present application;

Figure 2C is a schematic diagram of another possible communication system provided by an embodiment of the present application;

Figure 3 is a schematic diagram of yet another possible communication system provided by an embodiment of the present application;

Figure 4 is a schematic flowchart of an aging guarantee method provided by an embodiment of the present application;

Figure 5 is a schematic flowchart of a network device updating aging information provided by an embodiment of the present application;

Figure 6A is a schematic flowchart of another timeliness guarantee method provided by an embodiment of the present application;

Figure 6B is a flow chart of a method for updating the request message by a network device according to an embodiment of the present application;

Figure 7 is a schematic diagram of the specific implementation of an aging guarantee method provided by an embodiment of the present application;

Figure 8 is a flow chart of yet another timeliness guarantee method provided by an embodiment of the present application;

Figure 9 is a schematic flowchart of a response message transmission process provided by an embodiment of the present application;

Figure 10 is a schematic flowchart of a query method provided by an embodiment of the present application;

Figure 11 is a scene diagram of a nearby response provided by an embodiment of the present application;

Figure 12 is a schematic structural diagram of an aging guarantee device 120 provided by an embodiment of the present application;

Figure 13 is a schematic structural diagram of an aging guarantee device 130 provided by an embodiment of the present application;

Figure 14 is a schematic structural diagram of an aging guarantee device 140 provided by an embodiment of the present application.

Detailed ways

The embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. It should be noted that in this application, words such as “exemplary” or “for example” are used to represent examples, illustrations or explanations. Any embodiment or design described herein as "exemplary" or "such as" is not intended to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the words "exemplary" or "such as" is intended to present the concept in a concrete manner.

"At least one" mentioned in the embodiments of this application means one or more, and "multiple" means two or more. "At least one of the following" or similar expressions thereof refers to any combination of these items, including any combination of a single item (items) or a plurality of items (items). For example, at least one of a, b, or c can represent: a, b, c, (a and b), (a and c), (b and c), or (a and b and c), where a, b, c can be single or multiple. "And/or" describes the relationship between related objects, indicating that there can be three relationships. For example, A and/or B can mean: A alone exists, A and B exist simultaneously, and B exists alone, where A and B can be singular or plural. The character "/" generally indicates that the related objects are in an "or" relationship.

And, unless otherwise stated, the use of ordinal numbers such as "first" and "second" in the embodiments of this application is used to distinguish multiple objects and is not used to limit the order, timing, priority or importance of multiple objects. degree. For example, the first information and the second information are only used to distinguish different information, but do not indicate the difference in content, priority, sending order or importance of the two types of information.

Before introducing the embodiments of the present application, technical terms appearing in the embodiments of the present application are first introduced.

1. Industrial Protocol (IP)/Industrial Ethernet (Industrial Ethernet), Ethernet technology used in the field of industrial control.

2. Programmable Logic Controller (PLC) is an electronic device for digital operation specially designed for application in industrial environments.

3. Actuator can receive instructions issued by the controller and execute corresponding production actions.

In the following, combined with Figure 1, the existing technology method for ensuring message timeliness in industrial Ethernet is introduced.

Please refer to Figure 1. Figure 1 is a schematic diagram of an existing industrial Ethernet deployment provided by an exemplary embodiment of the present application. As shown in Figure 1, the industrial Ethernet includes a requester, N industrial gateways, a responder and a clock server, where N is a positive integer; the clock server can be a high-precision time synchronization server, and the requester can be a PLC controller , the responder is the Actuator.

In one implementation, the requester and responder can use a clock synchronization algorithm to ensure that the system time of both parties is consistent with the high-precision clock server time. Please refer to Figure 1. The requester can send a query instruction or a control instruction to the responder. The query instruction or control instruction includes timestamp information; the responder can determine whether the instruction satisfies the requirements based on the timestamp and system time in the above instruction. Timeliness requirements to determine whether the instruction needs to be executed; the responder can send a response message to the requester after receiving the query instruction.

The inventor of this application found that in this method, a high-precision time synchronization server needs to be deployed in the network, which involves deployment costs.

Therefore, embodiments of the present application propose an aging guarantee method, device and system. This method updates the aging information in the instruction through the network device. When receiving the instruction, the responder can determine whether execution needs to be performed based on the remaining aging in the instruction. this directive. This method does not require the deployment of a high-precision time synchronization server.

The system architecture and business scenarios of the embodiments of this application are described below. It should be noted that the system architecture and business scenarios described in this application are for the purpose of explaining the technical solution of this application more clearly and do not constitute a limitation on the technical solution provided by this application. Those of ordinary skill in the art will know that with the system architecture With the evolution of the Internet and the emergence of new business scenarios, the technical solutions provided in this application are also applicable to similar technical problems.

Please refer to Figure 2A. Figure 2A is a schematic diagram of a possible communication system provided by an embodiment of the present application. The communication system 10 includes a requester 101, a network device 102 and a responder 103. in:

As shown in Figure 2A, the requester 101 is connected to the responder 103 via the network device 102. For example, the requester 101 sends a request message to the network device 102, and the request message may include a query instruction or a control instruction; the network device 102 sends the request message to the responder 103. For another example, the responder 103 may send an active notification message or a response message to the network device 102, and the network device 102 then sends the active notification message or response message to the requesting party 101. It can be understood that the requester 101 can be the sender and the responder 103 can be the receiver; or the responder 103 can be the sender and the requester 101 can be the receiver, which can be determined according to specific scenarios.

Among them, the requester 101 may include at least one requester; the network device 102 may include at least one network device, and the network device may be a gateway, a switch, a network bridge, etc. Among them, the requester 101 can be a controller, and the responder 103 can be an executor. This is only an example and should not limit the requester 101 and the responder 103. In different application scenarios, the sender 301 and the receiver The terminal 302 can be different devices, which are not limited here.

It should be noted that in the case of multiple requesters and multiple network devices, the requester can communicate with the responder through some of the multiple network devices; different requesters can communicate with the responder through the same network device. The responder makes a communication connection or can establish a communication connection with the responder through different network devices, which is not limited here.

Please refer to Figure 2B, which is a schematic diagram of another possible communication system provided by an embodiment of the present application. FIG. 2B exemplarily shows that the communication system 20 includes a requester, n network devices and a responder, where the requester includes requester 1 and requester 2; the n network devices are network device 1 and network device 2 respectively. Until network device n, n is a positive integer greater than 2. Among them, requester 1 establishes a communication connection with network device 1, and requester 1 is connected to the responder through n network devices such as network device 1, network device 2, and network device n; requester 2 establishes communication with network device 2. Connection, requester 2 is connected to the responder via n-1 network devices from network device 2 to network device n.

Wherein, the communication link between the requester 101, the network device 102 and the responder 103 may include various types of connection media, including wired links (such as optical fibers), wireless links, or a combination of wired links and wireless links. Combination etc. For example, you can It is believed that short-range connection technologies include 802.11b/g, Bluetooth (blue tooth), Zigbee, radio frequency identification technology (radio frequency identification, RFID), ultra wideband (UWB) technology, and wireless short-range communication systems (such as vehicle-mounted wireless short-range communication systems), etc., and for example, long-distance connection technologies include communication technologies based on Long Term Evolution (Long Term Evolution), fifth generation mobile communication technologies (5th generation mobile networks or 5th generation wireless systems, 5th-Generation (referred to as 5G or 5G technology), global system for mobile communications (GSM), general packet radio service (GPRS), universal mobile telecommunications system , UMTS) and other wireless access type technologies.

Of course, there are other wireless communication technologies that can be used to support communication between network elements or devices in the communication system provided by this application.

It should be noted that the above communication system may also include other network elements or devices, which are not limited here.

Please refer to Figure 2C, which is a schematic diagram of another possible communication system provided by an embodiment of the present application.

As shown in FIG. 2C , the communication system 30 only includes a sending end 301 and a receiving end 302. The sending end 301 may include one or more sending ends. in:

The sending end 301 is used to send a data frame to the receiving end 302. The data frame includes aging information, and the aging information of the data frame is used to indicate the remaining aging of the data frame; the receiving end 302 is used to receive the data frame based on the link layer of the receiving end 302. The start time and the end time of the link layer receiving the data frame are obtained to obtain the link delay, and then based on the link delay and the reception processing delay, the remaining timeliness of the data frame is updated.

Further, the receiving end 302 can also determine whether the data frame is valid based on the updated remaining timeliness. For example, the data frame includes a query instruction or a control instruction. When the receiving end determines that the data frame is valid, the receiving end can execute the query instruction or control instruction; When it is determined that the data frame is invalid, operations such as discarding the data frame or replying an error code to the sending end can be performed.

In some embodiments, the data frame carries a request message, and the request message includes a query instruction or a control instruction. Then the receiving end 302 can determine whether the request message is valid based on the updated remaining time limit and the preset threshold. When determining that the request message is valid, Execute query instructions or control instructions.

Among them, the sending end 301 can be the above-mentioned requester, and the receiving end 302 can be the above-mentioned responder; or, the sending end 301 can be the above-mentioned responder, and then the receiving end 302 can be the above-mentioned requester. Among them, the requester can be a controller and the responder can be an executor. This is only an example and should not limit the sending end 301 and the receiving end 302. In different application scenarios, the sending end 301 and the receiving end 302 It can be different devices and is not limited here.

The following takes the industrial Ethernet environment as an example to further introduce the above communication system.

Please refer to Figure 3. Figure 3 is a schematic diagram of yet another possible communication system provided by an embodiment of the present application. The communication system includes N requesters, N network devices and responders, where N is a positive integer. It should be noted that in other embodiments, the number of requesters and the number of network devices may be the same or different, depending on the actual situation. N here is only an example and should not cause the number of requesters to be different from the number of network devices. Limitation on the number of network devices. in:

As shown in Figure 3, Figure 3 exemplarily shows the query and control scenario between the requester and the responder in the industrial Ethernet, where multiple requesters in the industrial Ethernet communicate with the responder via one or more network devices. connected. Figure 3 exemplarily shows Requester-1, Requester-2 and Requestor-N, as well as Network Device 1 and Network Device N, where Requester-1 and Requester-2 both establish communication with Network Device 1 Connection, the requester-N establishes a communication connection with the network device N. Among them, the network device can be used to cache the received information, such as caching the response message; and to perform timeliness management on the received information, that is, to update the timeliness information in the message; and can also perform message forwarding scheduling, such as forwarding a certain message based on timeliness priority. information.

Taking requester-1 as an example, requester-1 can send query instructions and/or control instructions to network device 1, and then the instructions reach the responder after passing through other network devices. Among them, N network devices can respond to the received The aging information in the instruction is updated; after receiving the instruction, the responder can determine whether to execute the instruction based on the aging information dynamically updated by N network devices; the responder can also send the response message corresponding to the instruction through other networks. The device sends it to network device 1, and then network device 1 will send the response message to requester-1. Among them, N network devices can update the timeliness information in the received response message; N network devices can cache the reception response message received.

After the network device caches the received response message, when other requesters request the response message from the responder through the network device, the network device nearby the other requester can send the cached response message to the requester. For example, the requester-2 can send a query instruction and/or a control instruction to the network device 2. After the network device 2 queries that there is a response message corresponding to the instruction in the storage and determines that the response message has not expired, the network device 2 can send the response message. The message is sent to requester-2.

Regarding the communication relationship between N requesters, N network devices and responders, as well as the implementation of timeliness update, please refer to the relevant description below for details, which will not be elaborated here.

As shown in Figure 3, Figure 3 exemplarily shows functional units in a network device, such as an information caching unit, an aging management unit, and a forwarding unit. Among them, the information cache unit is used to cache the information results obtained by the requester from the responder's query; the timeliness management unit is used to update the timeliness information of requests and response messages in real time; the forwarding unit can make decisions based on the real-time and reliability requirements of the information or instructions. Request and response messages are forwarded first, forwarded normally or discarded.

For a detailed description of the functional units in the network device, please refer to the relevant description below and will not be elaborated here.

It should be noted that the network device may also include more or less functional units as shown in Figure 3, which is not limited here.

Please refer to Figure 4. Figure 4 is a schematic flowchart of an aging guarantee method provided by an embodiment of the present application. Further, the method can be implemented based on the architecture shown in Figure 1, Figure 2A or Figure 2B. The method may include some or all of the following steps:

Step S401: The sending end sends a data frame to the receiving end. The data frame includes aging information. The aging information of the data frame is used to indicate the remaining aging of the data frame.

Among them, the data frame can carry any one of the request message, response message and active notification message; the request message can include a query instruction or a control instruction, the response message can be a reply message generated in response to the query instruction or control instruction, and the active notification message It is a message automatically sent by the sender to the receiver, such as notification messages sent regularly according to preset rules.

Step S402: The receiving end obtains the link delay based on the starting time of the receiving end's link layer receiving the data frame and the ending time of the link layer receiving the data frame.

In some embodiments, the receiving end may determine the time difference between the start time and the end time as the link delay, where the start time may be the time when the start bit of the data frame is received, and the end time may be the time when the start bit of the data frame is received. The moment of the end bit of the data frame. Among them, the start bit and the stop bit comply with the start bit coding (preamble or frame start delimiter) and stop coding (frame check sequence FCS) defined by the link layer frame format of the data frame.

Step S403: The receiving end updates the remaining aging based on the link delay and the reception processing delay. The reception processing delay is the time required for the protocol stack or the application layer to receive and process the data frame after the link layer receives the data frame.

In one implementation, the receiving end can subtract the link delay and the reception processing delay from the remaining aging in the data frame to obtain the updated remaining aging. Furthermore, the receiving end can also determine whether the data frame is within the time limit based on the updated remaining time limit. For example, the data frame includes a query instruction or a control instruction. When the receiving end determines that the data frame is valid, it can execute the query instruction or control instruction; when it determines that the data frame is invalid, it can discard the data frame or reply an error code to the sending end. Wait for operations.

In some embodiments, the data frame carries a request message, and the request message includes a query instruction or a control instruction, then the receiving end Whether the request message is valid can be determined based on the updated remaining aging and the preset threshold; further, when it is determined that the request message is valid, the query instruction or the control instruction is executed.

In some other embodiments, the sending end sends the data frame to the receiving end via at least one network device, and the network device can dynamically update the remaining validity of the received data frame. Please refer to Figure 5. Figure 5 is a schematic flowchart of a network device updating aging information provided by an embodiment of the present application. The method includes some or all of the following steps:

Step S501: The network device receives a data frame, the data frame includes aging information, and the aging information is used to indicate the remaining aging of the data frame.

The data frame can carry any of a request message, a response message and an active notification message; the request message can include a query instruction or a control instruction, and the response message can be a reply message generated in response to the query instruction or control instruction.

Step S502: The network device obtains the transmission delay based on the starting time when the link layer of the network device receives the data frame and the end time when the link layer receives the data frame.

In some embodiments, the transmission delay may be the time difference between the start time and the end time, where the start time is the time when the start bit of the data frame is received, and the end time is the time when the stop bit of the data frame is received. ;The remaining aging in the updated data frame is the remaining aging in the data frame minus the difference between the transmission delay and the overall forwarding delay.

Step S503: The network device obtains the overall forwarding delay based on the time required for the protocol stack or application layer of the network device to process the data frame.

In some embodiments, the overall forwarding delay includes receiving processing delay and sending processing delay; receiving processing delay is the time required for the protocol stack or application layer to receive and process the data frame after the link layer receives the data frame; sending processing time Delay is the time required for the protocol stack or the application layer to send and process the first data frame before the link layer sends the updated data frame.

The reception and processing delay may specifically be the time difference from the time when the link layer receives the data frame to the time when the protocol stack or application layer completes parsing the data frame; the protocol stack or application layer receiving and processing the data frame may specifically include The data frame is parsed and processed; the protocol stack or the application layer sends and processes the first data frame, which may specifically include packetizing the data frame.

Step S504: The network device updates the aging information based on the transmission delay and the overall forwarding delay.

In one implementation, the network device can update the remaining aging of the data frame to the first aging to obtain the first data frame. The first aging is the remaining aging of the data frame minus the difference between the transmission delay and the reception processing delay. The remaining aging of the first data frame is the first aging; then update the remaining aging of the first data frame to the second aging to obtain the updated data frame. The second aging is the difference between the first aging and the transmission processing delay, The remaining aging of the updated data frame is the second aging.

In some embodiments, the network device may determine a processing method for the first data frame based on the first timeliness; the processing method includes priority forwarding, normal forwarding, or discarding. For example, when it is determined that the first data frame should be forwarded first, the first data frame should be sent from the protocol stack or application layer to the link layer first, so that the network device can send the first data frame to the next network device as soon as possible. or responding party.

Optionally, the processing method for the first data frame may be determined based on at least one of the reliability level corresponding to the data frame and the real-time level corresponding to the data frame and the first timeliness.

In other embodiments, the network device may also store the first data frame. For example, the data frame is a data frame that carries a response message generated by the responder in response to the query instruction of the first requester, and the network device can store the response message. For example, the network device may update the remaining timeliness of the data frame to the first timeliness and obtain the first data frame, and then store the first data frame when the first timeliness and the real-time level corresponding to the response message satisfy the cache decision. Then, if the network device receives a query instruction from another requester, and the network device stores a response message requested by the query instruction, the network device can send a response message to the second requester. Among them, the network device may store the first data frame, or the first data frame may carry The response message may specifically be the message content of the first data frame, such as the query content corresponding to the query instruction in the request message, etc.

Optionally, the network device may send the response message to the second requester after determining that the stored response message is valid; and forward the request message to the responder when determining that the response message has expired. For example, the network device can obtain the first aging corresponding to the response message and the time when the response message is stored; when the time difference between the current time and the time when the response message is stored is not greater than the first aging, send the response message to the second requester; at the current time When the time difference from the time when the response message is stored is greater than the first time limit, a request message is sent to the responder.

Step S505: The network device sends the updated data frame.

In some embodiments, after updating the timeliness information of the data frame, the network device forwards the updated data frame to the next network device or responder.

The above method embodiments shown in Figures 4 and 5 include many possible implementation solutions. Some of the implementation solutions are illustrated below with reference to Figures 6A to 11. It should be noted that Figures 6A to 11 are not explained. For related concepts, operations or logical relationships, please refer to the corresponding descriptions in the embodiments shown in Figures 4 and 5.

Please refer to Figure 6A. Figure 6A is a schematic flowchart of another timeliness guarantee method provided by an embodiment of the present application. This method can be implemented based on the architecture shown in Figure 2A. The timeliness guarantee method may include the following steps:

Step S601: The requesting party sends a request message to at least one network device. The request message is used to request the responder to respond to the control instruction or query instruction in the request message. The request message includes aging information, and the aging information is used to indicate the request message. Remaining time limit.

The request message may include a query instruction or a control instruction. For example, the request message includes a query instruction or a control instruction, and the timing information of the instruction. The aging information may be indication information or a numerical value used to indicate the remaining aging. For example, the aging information may be 1 second or indication information indicating 1 second.

Wherein, at least one network device may be one or more network devices. For example, when at least one network device is a network device, the requesting party sends a request message to at least one network device, that is, the requesting party sends a request message to the network device, and the network device sends the request message to the responder; in at least one network When the device is multiple network devices, the requesting direction sends a request message to at least one network device. The requesting direction sends a request message to one network device among the multiple network devices. The network device among the multiple network devices will send a request message to the responder based on the request. The data communication link forwards the request message in sequence until it is forwarded to the responder.

Step S602: Each network device in at least one network device updates the aging information in the received request message.

Assume that the above-mentioned at least one network device includes network device N. The following takes network device N as an example to introduce a specific implementation of the network device's timeliness update of the request message.

Please refer to FIG. 6B. FIG. 6B is a flow chart of a method for a network device to update the timeliness of a request message according to an embodiment of the present application. The method includes some or all of the following steps:

Step S6021: Based on the received request message, network device N calculates the transmission delay and the overall forwarding delay. The overall forwarding delay includes the receiving processing delay and the sending processing delay.

The network device N may be a first network device that directly communicates with the requesting party, or may be a second network device that communicates with the requesting party indirectly. As shown in Figure 3, assuming that the requesting party is requesting party-N, then network device N is a network device that directly communicates with the requesting party (that is, the above-mentioned first network device), that is, the requesting party directly sends the request message to the first network device. ; Assume that the requesting party is requesting party-1, and the network device N is a network device that indirectly communicates with the requesting party (ie, the above-mentioned second network device).

In some embodiments, considering the industrial Ethernet scenario, the requester and the responder are deployed close to each other, and the data of the instruction The transmission delay of frames between network devices can be equivalent to the time difference between the start bit time Ts and the end bit time Te of the network element receiving port receiving the data frame ΔTt = Te – Ts; the forwarding delay of the data frame within the network device , can be divided into two parts, the receiving processing delay ΔTp = T – Te and the sending processing delay ΔTp’ = Ts’ – T, where Ts’ is the time when the sending port sends the starting bit of the data frame of the instruction, and the overall forwarding time It can be expressed as ΔTf=ΔTp+ΔTp'. The processing time T is the time when the data frame is processed in the protocol stack or application layer. The specific processing may include operations such as parsing the data frame.

It should be noted that the above-mentioned transmission delay can also be called link delay. For convenience of description, it is referred to as transmission delay below.

Step S6022: Network device N calculates the first aging Pn based on the transmission delay and the reception processing delay.

In some embodiments, network device N may subtract the transmission delay and the reception processing delay from the remaining timeliness in the received request message to obtain the first timeliness.

Step S6023: Network device N updates the remaining aging in the request message to the first aging Pn, and obtains the cached message.

In some embodiments, network device N may update the remaining age in the request message to the first age Pn to obtain the cached message.

Step S6024: Network device N accelerates forwarding, normally forwards, or discards the cached message based on the first timeliness Pn, real-time requirements, and reliability requirements.

The network device N accelerates forwarding or normally forwards the cached message. Specifically, the network device N accelerates forwarding or normally forwards the cached message in the process of sending the cached message from the protocol stack or application layer to the link layer.

For example, normal forwarding is to send the messages in the sending queue from the protocol stack or application layer to the link layer in order from front to back; assuming that there are several messages in the sending queue in front of the cached message, then normal forwarding is, the network The device sequentially sends several messages from the protocol stack or application layer to the link layer, and then sends the cached message from the protocol stack or application layer to the link layer; priority forwarding is to first send the cached message from the protocol stack or application layer Send to the link layer, and then send several messages from the protocol stack or application layer to the link layer in turn.

In one implementation, the network device N can calculate the priority level Q=f(Pn|R|R') of the message based on Pn combined with the real-time requirement R and reliability requirement R' of the instruction. When Q>Qhigh, high priority is given. Level forwarding, Qhigh≥Q≥Qdrop means normal forwarding, or Q<Qdrop means discarding the message. Among them, Qhigh and Qdrop can be preset thresholds, and Q=f(Pn|R|R') is a preset function.

Step S6025: Network device N updates the remaining aging in the cached message to the second aging P'n to obtain the updated request message. The second aging is the time period obtained by subtracting the transmission processing delay from the first aging.

In one implementation, the network device receives the cached message at the link layer, and updates the remaining aging in the cached message to the second aging P'n in the link layer summary. The second aging is the time period obtained by subtracting the transmission processing delay from the first aging.

Step S6026: Network device N forwards the updated request message to the next network device or responder.

The next network device refers to the network device next to the network device N on the communication link from the requester to the responder. For example, when the requester sends a message to the responder, it needs to be sent by the requester to network device N, which is forwarded to network device N+1, and then sent by network device N+1 to the responder. Then the next network device of the network device is Refers to network device N+1.

Step S603: At least one network device sends the updated request message to the responder.

In some embodiments, each network device in at least one network device updates the remaining aging in the received request message, and sends the request message after all network devices have updated the aging to the responder.

Assume that the request message from the requester is sent to the responder after passing through two network devices, and the initial remaining time limit in the request message is T1; after the first network device receives the request message sent by the requester, it sends the remaining time limit of the request message to the responder. The time limit is updated to T2, which is T1 minus the transmission delay and overall forwarding delay calculated by the first network device; after receiving the request message sent by the first network device, the second network device transfers the remainder of the request message. The timeliness is updated to T3, which is T2 minus the transmission delay calculated by the second network device and the overall forwarding delay; finally, the second network device sends the updated request message. Sent to the responder, the remaining time limit for the responder to receive the request message is T3, and the responder can determine whether the request message meets the time limit based on T3. Among them, T1, T2, and T3 are all positive numbers. It is understandable that T1>T2>T3.

Step S604: In response to the received request message, the responder sends a response message to at least one network device. The response message includes aging information, and the aging information is used to indicate the remaining aging of the response message.

The request message includes a query instruction or a control instruction, as well as the instruction's aging information; after receiving the request, the responder can first determine whether the instruction is valid based on the aging information, execute the instruction when it is valid, and generate the The response message corresponding to the command.

For example, when the query instruction is valid, the responder can perform a query in response to the query instruction and obtain the query information; and then generate a response message, which includes the query information. For another example, when the control instruction is valid, the responder can perform control operations in response to the instruction; it can also generate a response message, which includes control results or control parameters.

The responder can determine whether the request message is valid based on the timeliness information, and the determination method is not limited here. For example, the responder may determine that the message has expired when the remaining age of the message is less than 0; or determine that the message has expired when the remaining age of the message is less than a preset threshold. It can be understood that in the embodiment of the present application, the responder does not need to establish time synchronization with the requester. The responder can determine whether the message is valid based only on the remaining time limit and the preset threshold.

In some embodiments, when receiving the request message, the responder calculates the link delay and the reception processing delay of the request message; and then updates the remaining messages of the request message based on the link delay and the reception processing delay. The remaining aging determines whether the request message is valid. Among them, the link delay can be obtained based on the start time and end time of the responder receiving the data frame carrying the request message. The reception processing delay is the protocol stack or application layer after the responder's link layer receives the data frame. The time required to receive and process a data frame. For the specific method for the responder to calculate the link delay and the reception processing delay, please refer to the relevant content of the network device to calculate the transmission delay and the reception processing delay, and will not be described again here.

Step S605: Each network device in at least one network device updates the aging information of the received response message.

In some embodiments, the process of updating the aging information of the received response message by each network device in at least one network device may be consistent with the process of updating the aging information of the request message. For details, please refer to the above-mentioned network device updating the request message. The relevant content of timeliness update will not be described again here.

Step S606: At least one network device sends the updated response message to the first requester.

In some embodiments, each network device in at least one network device updates the remaining aging in the received response message, and sends the response message after all network devices have updated the aging to the responder.

A possible specific implementation of the above steps S601 to S606 will be described in detail below with reference to FIG. 7 .

As shown in FIG. 7 , FIG. 7 exemplarily shows a requester, a responder, and network device N and network device N+1 among multiple network devices. The requester can send a request message to the responder via multiple network devices, and the responder can send a response message to the requester via multiple network devices.

It can be understood that when the requester sends a request message to the responder via multiple network devices, the requester is the sender and the responder is the receiver; when the responder sends a response message to the requester via multiple network devices, the responder is the sender, and the requester is the receiver.

Among them, when the requesting party sends a query or control instruction, the request message carries the aging information P of the instruction; the response message of the query instruction also carries the query information ID and information value V as well as the information aging information P. As shown in Figure 7, Figure 7 exemplarily shows the information included in the request message and the response message, such as information ID, information value V and aging information.

Considering the industrial Ethernet scenario, the requester and responder are deployed close to each other, and the instruction data frame is transmitted between network devices. The transmission delay can be equivalent to the time difference ΔTt = Te – Ts between the start bit time Ts and the end bit time Te of the data frame received by the network element receiving port; the forwarding delay of the data frame in the network device can be divided into two parts , the receiving processing delay ΔTp=T–Te and the sending processing delay ΔTp’=Ts’–T, where T is the time when the protocol stack or application reception processing is completed, and Ts’ is the start of the data frame of the sending port sending instructions bit time, the overall forwarding delay can be expressed as ΔTf=ΔTp+ΔTp'.

Taking network device N as an example, as shown in Figure 7, the time difference between the start bit time Tsn and the end bit time Ten of the data frame received by the receiving port of network device N is ΔTtn = Ten – Tsn; the forwarding delay of the data frame within the network device , can be divided into two parts, the receiving processing delay ΔTpn=Tn–Ten and the sending processing delay ΔTp'n=Ts'n–Tn, where Tn is the time when the protocol stack or application reception processing is completed, and Ts'n is the sending time. At the time when the port sends the starting bit of the data frame of the command, the overall forwarding delay can be expressed as ΔTfn = ΔTp n + ΔTp'n.

Furthermore, the network device N can calculate Pn and P'n based on the transmission delay and the overall forwarding delay. The specific formula for calculating Pn and P'n by network device N can be shown in Figure 7. The timeliness for network device N to receive the request message is P' _n-1 , Pn=P' _n-1 – ΔTtn – ΔTpn, where ΔTtn is The transmission delay calculated by network device N, ΔTpn is the receiving processing delay calculated by network device N; P'n=Pn-ΔTp'n, where ΔTp'n is the sending processing delay calculated by network device N.

Among them, each network device on the link updates the remaining timeliness information Pn in the request message and response message, and calculates the message priority Q=f(Pn|R| based on Pn combined with the real-time requirement R and reliability requirement R' of the instruction). R'), when Q>Qhigh, high-priority forwarding is performed, Qhigh≥Q≥Qdrop, normal forwarding is performed, or Q<Qdrop, the message is discarded. Among them, Qhigh and Qdrop can be preset values.

Before forwarding the message, each network device on the link can update the remaining aging information in the message. Taking network device N as an example, before forwarding the request message, network device N can further update the aging based on ΔTp'n. As shown in Figure 7, the aging in the message forwarded by network device N is P'n.

It is understandable that each network device does not need to rely on an external clock server and only needs to calculate the transmission delay based on the data frame structure of the instruction; the network device can update the remaining timeliness of the message in real time based on the transmission path of the request message and response message; the network The device can improve the response speed of instructions by combining the remaining timeliness of the request message and response message with the real-time requirements and reliability requirements of the message.

In other embodiments, the network device may process the response message differently from the request message.

The following is an exemplary introduction to another timeliness guarantee method provided by the embodiment of the present application.

In this method, the network device on the communication link between the requester (first requester) and the responder can store the updated response message, so that other requesters (ie, the second requester) can request the same response message when , network devices on the communication link can send stored response messages to other requesters. It can be understood that the above steps S604 to step S606 can be replaced by step S802 in the embodiment of the present application.

Please refer to Figure 8. Figure 8 is a flow chart of yet another timeliness guarantee method provided by an embodiment of the present application. The method includes the following steps:

Step S801: The first requester sends a query instruction to the responder via at least one network device, and the at least one network device includes network device N.

The query instruction may include aging information corresponding to the instruction, and the aging information is used to indicate the remaining aging of the query instruction.

In some embodiments, the process of the first requester sending a query instruction to the responder via at least one network device also includes sending aging information corresponding to the instruction; each network device in the at least one network device can update the received query instruction. Corresponding aging information; furthermore, the responder can receive the aging information updated by each network device, and determine whether the query instruction is valid based on the remaining aging of the query instruction.

It should be noted that for the specific implementation of the first requester sending the query instruction to the responder via at least one network device, please refer to the relevant content of steps S601 to S603 above, which will not be described again here.

Step S802: In response to the received query instruction, the responder sends a response message to the first requester via at least one network device, where the response message includes aging information indicating the remaining aging.

In some embodiments, after receiving the query instruction, the responder performs a query to obtain the target information; then, generates a response message that includes the target information; and then sends the response message to the first network device via at least one network device. requesting party.

Wherein, after receiving the response message, each network device in at least one network device can update the remaining time limit in the response message; the response message can also be stored.

The following takes network device N as an example to introduce in detail a specific operation of network device N after receiving the response message.

Step S8021: After receiving the response message, network device N updates the remaining aging indicated by the aging information to the first aging and obtains the cached message. The first aging is the time period of the remaining aging minus the transmission delay and the reception processing delay. .

Among them, the specific process of the network device N calculating the transmission delay and the reception processing delay can be found in the relevant description above, and will not be described again here.

Step S8022: Network device N stores the cached message when the first delay meets the preset condition.

In one implementation, network device N can make a caching decision based on the first delay to determine whether to store the cached message. For example, each network device can calculate the storage level S=f'(Pn|R) based on the remaining timeliness information Pn of the information in the response message combined with the real-time requirements of the information, and store the information when S>Sstore for subsequent network devices. Quick processing when receiving query instructions for the same information. Among them, Sstore can be a preset threshold, and S=f'(Pn|R) is a preset function.

Storing the cache message may specifically store the cache message, or may store the message content corresponding to the cache message. For example, it may store the content requested by the query instruction corresponding to the response message, etc.

In some embodiments, each of at least one network device stores the cached message. Then, when a requester in direct communication with the network device requests a response message corresponding to the query instruction, the network device can send the cached message. to the requesting party. It is understandable that this method can achieve nearby response and improve the speed of response. For content such as network device query cache messages, please refer to the following descriptions of steps S8026 to S8028.

It should be noted that in other embodiments, some of the network devices in at least one network device may store the cached message, which may be determined according to the actual situation, and is not limited here.

Step S8023: Based on the first delay, network device N determines whether to forward the buffered message with priority or to forward it normally.

The process by which the network device N determines whether to forward the cached message first or normally based on the first delay may refer to the relevant content in step S6024, which will not be described again here.

Step S8024: Network device N updates the remaining aging of the cached message to the second aging to obtain the updated response message. The second aging is the time period of the first aging minus the transmission processing delay.

For the process of the network device N updating the remaining aging of the cached message to the second aging, please refer to the relevant content in step S6025, which will not be described again here.

Step S8025: Network device N sends the updated response message to the next network device or the first requester.

The next network device refers to the network device next to the network device N on the communication link from the responder to the requester. For example, when the requester sends a message to the responder, it needs to be sent by the requester to network device N, which is forwarded to network device N-1, and then sent by network device N-1 to the responder. Then the next network device of the network device is Refers to network device N-1.

A possible specific implementation of the timeliness guarantee method shown in Figure 8 is introduced below with reference to Figure 9 .

Figure 9 takes the scenario where the responder responds to the query instruction sent by the requester-1 and sends a response message to the requester-1 as an example. Introduce the transmission process of response messages. It should be noted that the process of the requester-1 sending the query instruction to the responder can be found in the relevant description above and will not be described again here.

Please refer to Figure 9. Figure 9 is a schematic flowchart of a response message transmission process provided by an embodiment of the present application.

As shown in Figure 9, the communication link between the requester-1 and the responder for message transmission includes multiple network devices. Figure 9 exemplarily shows network device 1 and network device N, where network device 1 and the requesting party Party-1 establishes a communication connection. Specifically, the requester-1 can send a query command to the network device 1, and then the network device 1 sends the query command to the next network device on the communication link, and so on, until the last network device sends the query command. to the responder; the responder can respond to the query command and generate a response message, which can carry the information ID, information value V and aging information; the response message is sent to network device 1 via multiple network devices on the communication link, The response message is sent by network device 1 to requester-1. The response message includes a remaining time limit that is continuously updated dynamically with the network equipment on the communication link. The remaining time limit can be used by the requesting party-1 to determine whether the response message is valid based on the remaining time limit.

Among them, each network device can calculate the storage level S=f'(Pn|R) based on the remaining timeliness information Pn of the information in the response message combined with the real-time requirements of the information. When S>Sstore, the information is stored for subsequent network devices. Quick processing when receiving query instructions for the same information. Among them, Sstore can be a default value.

Taking network device N as an example, the aging in the response message received by network device N is P' _n+1 . Network device N can first calculate the aging Pn based on the aging P' _n+1 , where the aging Pn is P' _{n+ 1} The aging after subtracting the transmission delay and the reception processing delay; furthermore, the network device N can make a caching decision for the response message based on the aging Pn. Specifically, the network device N can combine the remaining aging information Pn of the information in the response message. The real-time nature of this information requires calculating the storage level S=f'(Pn|R). When S>Sstore, the information is stored for rapid processing when subsequent network devices receive query instructions for the same information; furthermore, the network device N The response message can be forwarded based on the timeliness Pn, and the response message can be forwarded with high priority or normal forwarding. Finally, the network device N updates the timeliness information in the response message and updates the timeliness to P' _n , where the timeliness P' _n is the aging time after Pn minus the transmission processing delay.

Among them, the specific process of the network device N calculating the transmission delay, the reception processing delay, and the sending processing delay can be found in the relevant content above.

Based on the timeliness guarantee method shown in Figures 8 and 9, embodiments of the present application provide a query method. In this method, since the network device stores the response message transmitted through it, the network device can directly send the stored response message to the requesting party when receiving a query instruction to query the response message.

The following uses network device N as an example to introduce the query method in conjunction with Figure 10. Please refer to Figure 10. Figure 10 is a schematic flow chart of a query method provided by an embodiment of the present application. As shown in Figure 10, the query method may include all or part of the following steps:

Step S8026: Network device N receives the query instruction from the second requester.

The network device N may be a network device that directly communicates with the second requester; it may also be a network device that indirectly communicates with the second requester.

Step S8027: Network device N queries the storage for the response message corresponding to the query instruction.

In some embodiments, after receiving the query instruction, the network device N may first query the stored cache message to see whether there is a response message corresponding to the query instruction.

Step S8028: When the queried response message meets the preset conditions, the network device N sends a response message to the second requester.

In one implementation, when the queried response message is not invalid, the network device N sends a response message to the second requester. The network device N may determine whether the response message is invalid based on the remaining timeliness of the response message. For example, network device N Query the storage time and current time of the response message, calculate the time difference between the storage time and the current time, and then subtract the above time difference from the remaining aging. If the remaining aging is less than the preset threshold, the response message is determined to be invalid. If the remaining aging is greater than the preset The threshold value determines that the response message is valid, where the preset threshold value can be 0 or other values, which is not limited here.

In some embodiments, when other requesters in the network query the responder for information through network devices, network devices at all levels check the local information cache first. If the information cache exists and has not expired, the locally cached information will be responded to, otherwise it will be forwarded. This query is directed to the responder.

In a possible implementation, network device N is a network device that indirectly communicates with the second requester. For example, the second requester communicates with the responder through two network devices. The second requester sends a query command to network device N-1, and then network device N-1 updates the aging information of the query command and forwards it to the network device. N, is finally sent to the responder by network device N, then network device N is a network device that indirectly communicates with the second requester. When the network device N-1 does not store the response message corresponding to the query command, the network device N-1 updates the timeliness information of the query command and forwards the updated query command to the network device N. After the network device N queries When querying the response message corresponding to the instruction, network device N can send the response message to network device N-1, and then network device N-1 sends the response message to the second requester. When the network device N sends the response message to the second requester via the network device N-1, both the network device N and the network device N-1 can update the remaining aging in the response message.

It can be understood that the network device is a network device that establishes a direct communication connection with the requesting party. Then, the network device executes the query method shown in Figure 10 above to achieve a nearby response; the network device is a network device that establishes an indirect communication connection with the requesting party. , it can also reduce the time that originally needs to be sent to the responder.

Please refer to Figure 11, which is a scene diagram of a nearby response provided by an embodiment of the present application.

As shown in Figure 11, Figure 11 exemplarily shows Requester-1, Requester-2 and Requester-N, as well as Network Device 1 and Network Device N, where Requester-1 and Requester-2 both A communication connection is established with network device 1, and the requester-N establishes a communication connection with network device N.

For example, requester-1 is the above-mentioned first requester, and requester-2 and requester-N are the above-mentioned second requesters. Specifically, the communication between requester-1 and the responder includes multiple network devices such as network device 1 and network device N shown in Figure 11 . Assume that the requester-1 sends a query instruction to the network device 1, and then, in the process of the responder sending the response message corresponding to the query instruction to the requester-1 through the above-mentioned multiple network devices, multiple network devices all respond to the response message. It is updated within the time limit, and multiple network devices store the updated response messages.

Then, when the requester-2 sends the above query command to the network device 2, the network device 2 can first query the response message corresponding to the query command in the storage, and after querying the corresponding response message, send the response message to the requester Party-2; When the requesting party-N sends a query instruction to the network device N, the network device 2 can first query whether there is a response message corresponding to the query instruction in the storage, and after querying the corresponding response message, send the response message To Requester-N.

The response message stored by the network device may be updated with the response message received by the network device to a response message after the first aging (such as the cache message mentioned above), and the network device performs aging update on the response message. See the relevant description above and will not go into details here.

Figure 11 exemplarily shows the information carried in the response message, such as information ID, information value and aging information. It can be understood that the initial timeliness of the response message generated by the responder is P, and multiple network devices can update the timeliness information in the response message. For example, network device N updates the timeliness of the response message to Pn, and network device 1 updates the timeliness of the response message to _Pn . The response message is updated to P ₁ .

The method of the embodiment of the present application is described in detail above, and the device of the embodiment of the present application is provided below.

Please refer to Figure 12. Figure 12 is a schematic structural diagram of an aging guarantee device 120 provided by an embodiment of the present application. Setting 120 can be a network device. Of course, the device 120 can also be a component in a network device, such as a chip or an integrated circuit. The device 120 can include a receiving unit 1201, a first processing unit 1202, a second processing unit 1203, an updating unit 1204 and a sending unit 1205. . The aging guarantee device 120 is used to implement the aforementioned aging guarantee method, such as the aging guarantee method in any embodiment shown in Figure 5 or Figure 6B.

In a possible implementation, the receiving unit 1201 is configured to receive a data frame, the data frame includes aging information, and the aging information is used to indicate the remaining aging of the data frame;

The first processing unit 1202 is used to obtain the transmission delay based on the starting time of the link layer receiving the data frame and the ending time of the link layer receiving the data frame of the network device;

The second processing unit 1203 is used to obtain the overall forwarding delay based on the time required for the protocol stack or application layer of the network device to process the data frame;

The update unit 1204 is used to update the aging information based on the transmission delay and the overall forwarding delay;

The sending unit 1205 is used to send the updated data frame.

In a possible implementation, the transmission delay is the time difference between the start time and the end time; the start time is the time when the start bit of the data frame is received, and the end time is the time when the stop bit of the data frame is received. ;

In a possible implementation, the overall forwarding delay includes receiving processing delay and sending processing delay; the update unit 1204 is used to:

In a possible implementation, before the sending unit 1205 sends the updated data frame, the device further includes a processing unit, and the processing unit is configured to:

In a possible implementation, the processing unit is used for:

In a possible implementation, the data frame carries any one of a request message, a response message and an active notification message. The request message includes a query instruction or a control instruction, and the response message is a reply message generated in response to the query instruction or control instruction. .

In a possible implementation, the data frame carries a response message generated by the responder in response to the query instruction of the first requester. The device further includes a storage unit, and the storage unit is used for:

Store the response message.

In a possible implementation, the storage unit is used for:

In a possible implementation, the receiving unit 1201 is configured to receive a query instruction from the second requester, and the query instruction from the second requester is used to request a response message;

The sending unit 1205 is used to send a response message to the second requester.

In a possible implementation, the sending unit 1205 is used to:

It should be noted that the implementation of each unit may also correspond to the corresponding description with reference to the embodiment shown in FIG. 6A or FIG. 8 . The timeliness guarantee device 120 may be the network device in the embodiment shown in FIG. 6A or FIG. 8 .

It can be understood that in each device embodiment of the present application, the division of multiple units or modules is only a logical division based on functions and does not limit the specific structure of the device. In specific implementation, some functional modules may be subdivided into more small functional modules, and some functional modules may also be combined into one functional module. However, no matter whether these functional modules are subdivided or combined, the device 120 is paired with The general process performed is the same. For example, the receiving unit 1201 and the sending unit 1205 in the above-mentioned device 120 can also be integrated into a communication unit, and the communication unit can realize the functions realized by the receiving unit 1201 and the sending unit 1205. Usually, each unit corresponds to its own program code (or program instruction). When the corresponding program codes of these units are run on the processor, the unit is controlled by the processing unit and executes the corresponding process to realize the corresponding function.

Please refer to Figure 13. Figure 13 is a schematic structural diagram of a timeliness guarantee device 130 provided by an embodiment of the present application. The device 130 can be a receiving end. Of course, the device 130 can also be a device in the receiving end, such as a chip or an integrated circuit. The device 130 can include a receiving unit 1301, a processing unit 1302 and an updating unit 1303. The timeliness guarantee device 130 may be the responder or the requester in the above embodiment, and is used to implement the aforementioned timeliness guarantee method, such as the timeliness guarantee method in any embodiment shown in FIG. 6A or FIG. 8 .

In a possible implementation, the device includes:

The receiving unit 1301 is used to receive a data frame from the sending end; the data frame includes aging information, and the aging information of the data frame is used to indicate the remaining aging of the data frame;

The processing unit 1302 is configured to obtain the link delay based on the starting time of the receiving end's link layer receiving the data frame and the ending time of the receiving end's link layer receiving the data frame;

The update unit 1303 is used to update the remaining aging based on the link delay and the reception processing delay; the reception processing delay is the time required for the protocol stack or the application layer to receive and process the data frame after the link layer receives the data frame.

In a possible implementation, the data frame carries a request message, and the request message includes a query instruction or a control instruction; the device also includes an execution unit 1304, and the execution unit 1304 is used to:

In a possible implementation, the receiving unit 1301 is used for:

It should be noted that the implementation of each unit may also correspond to the corresponding description with reference to the embodiment shown in FIG. 6A or FIG. 8 . The timeliness guarantee device 130 may be the responder or requester in the embodiment shown in FIG. 6A or FIG. 8 .

Please refer to Figure 14. Figure 14 is a schematic structural diagram of a timeliness guarantee device 140 provided by an embodiment of the present application. The timeliness guarantee device 140 can be a node or a device in the node, such as a chip or an integrated circuit. Should be installed The device 140 may include at least one processor 1402 and a communication interface 1404. Further optionally, the timeliness guarantee device may also include at least one memory 1401. Further optionally, a bus 1403 may also be included, wherein the memory 1401, the processor 1402 and the communication interface 1404 are connected through the bus 1403.

Among them, the memory 1401 is used to provide storage space, and data such as operating systems and computer programs can be stored in the storage space. The memory 1401 may be a random access memory (RAM), a read-only memory (ROM), an erasable programmable read only memory (EPROM), or a portable read-only memory. One or more combinations of memory (compact disc read-only memory, CD-ROM), etc.

The processor 1402 is a module that performs arithmetic operations and/or logical operations, and may be a central processing unit (CPU), a graphics processing unit (GPU), a microprocessor unit (MPU), Application Specific Integrated Circuit (ASIC), Field Programmable Gate Array (FPGA), Complex programmable logic device (CPLD), co-processor (assist the central processor to complete Corresponding processing and application), microcontroller unit (Microcontroller Unit, MCU) and other processing modules or a combination thereof.

Communication interface 1404 may be used to provide information input or output to the at least one processor. And/or the communication interface can be used to receive data sent from the outside and/or send data to the outside. It can be a wired link interface such as an Ethernet cable, or a wireless link (Wi-Fi, Bluetooth, Universal wireless transmission, vehicle short-distance communication technology, etc.) interface. Optionally, the communication interface 1404 may also include a transmitter (such as a radio frequency transmitter, an antenna, etc.) or a receiver coupled to the interface.

The processor 1402 in the device 140 is used to read the computer program stored in the memory 1401 and execute the aforementioned aging guarantee method, such as the aging guarantee method described in the embodiment shown in FIG. 6A or FIG. 8 .

In one design, the timeliness guarantee device 140 may be the network device in the embodiment shown in FIG. 6A or FIG. 8 . The processor 1402 in the device 140 is used to read the computer program stored in the memory 1401 and execute the method embodiment shown in FIG. 6A or FIG. 8 .

In another design, the timeliness guarantee device 140 may be the requester or the responder in the embodiment shown in FIG. 6A or FIG. 8 . The processor 1402 in the device 140 is used to read the computer program stored in the memory 1401 and execute the method embodiment shown in FIG. 6A or FIG. 8 above.

For specific implementation, reference may also be made to the detailed description in the embodiment shown in FIG. 6A, FIG. 6B, FIG. 8 or FIG. 10, which will not be described again here.

Embodiments of the present application also provide a computer-readable storage medium. A computer program is stored in the computer-readable storage medium. When the computer program is run on one or more processors, FIG. 6A and FIG. 6B are implemented. , the method described in the embodiment shown in Figure 8 or Figure 10.

Embodiments of the present application also provide a chip system. The chip system includes at least one processor and a communication interface. The communication interface is used to send and/or receive data. The at least one processor is used to call at least one memory. The stored computer program implements the method described in the embodiment shown in FIG. 6A, FIG. 6B, FIG. 8 or FIG. 10.

Further, the at least one processor may include at least one of a CPU, MPU, MCU or a co-processor.

Embodiments of the present application also provide a computer program product. When the computer program product is run on one or more processors, the embodiments described in Figure 6A, Figure 6B, Figure 8 or Figure 10 can be implemented. Methods.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof.

When implemented using software, it may be implemented in whole or in part in the form of a computer instruction product.

When the computer instructions are loaded and executed on the computer, the processes or functions described in the embodiments of this application can be realized in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable device. The computer instructions may be stored in or transmitted over a computer-readable storage medium. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center integrated with one or more available media. Available media may be magnetic media (eg, floppy disk, hard disk, tape), optical media (eg, DVD), or semiconductor media (eg, solid state disk (SSD)), etc.

The steps in the method embodiments of this application can be sequence adjusted, combined, and deleted according to actual needs.

Modules in the device embodiments of the present application can be merged, divided, and deleted according to actual needs.

Claims

A timeliness guarantee method, characterized in that it is applied to network equipment, and the method includes:

Receive a data frame, the data frame including aging information, the aging information being used to indicate the remaining aging of the data frame;

Obtain the transmission delay based on the starting time when the link layer of the network device receives the data frame and the ending time when the link layer receives the data frame;

Based on the time required for the protocol stack or application layer of the network device to process the data frame, the overall forwarding delay is obtained;

Based on the transmission delay and the overall forwarding delay, update the aging information;

Send the updated data frame.
The method according to claim 1, characterized in that the transmission delay is the time difference between the starting time and the ending time; the starting time is when the starting bit of the data frame is received. time, and the termination time is the time when the termination bit of the data frame is received;

The remaining timeliness in the updated data frame is the remaining timeliness in the data frame minus the difference between the transmission delay and the overall forwarding delay.
The method according to claim 1 or 2, characterized in that the overall forwarding delay includes a receiving processing delay and a sending processing delay; and based on the transmission delay and the overall forwarding delay, update The timeliness information includes:

Update the remaining aging of the data frame to the first aging to obtain the first data frame; the first aging is the remaining aging of the data frame minus the difference between the transmission delay and the reception processing delay ; The reception and processing delay is the time required for the protocol stack or the application layer to receive and process the data frame after the link layer receives the data frame; the remaining aging of the first data frame is the The first statute of limitations is mentioned;

Update the remaining aging of the first data frame to a second aging to obtain the updated data frame; the second aging is the difference between the first aging and the sending processing delay, and the sending The processing delay is the time required for the protocol stack or the application layer to send and process the first data frame before the link layer sends the updated data frame; the remaining aging of the updated data frame is the second aging period.
The method according to claim 3, characterized in that, before sending the updated data frame, the method further includes:

Based on the first aging, a processing method for the first data frame is determined; the processing method includes priority forwarding, normal forwarding, or discarding.
The method of claim 4, wherein determining a processing method for the first data frame based on the first timeliness includes:

Based on at least one of the reliability level corresponding to the data frame and the real-time level corresponding to the data frame and the first timeliness, a processing method for the first data frame is determined.
The method according to any one of claims 1 to 5, characterized in that the data frame carries any one of a request message, a response message and an active notification message, and the request message includes a query instruction or a control instruction, The response message is a reply message generated in response to the query instruction or the control instruction.
The method according to any one of claims 1-6, characterized in that the data frame carries the responder's response to the first A response message generated by the query instruction of the requesting party, the method further includes:

Store the response message.
The method according to claim 7, characterized in that, after updating the remaining time limit of the data frame to the first time limit and obtaining the first data frame, storing the response message includes:

When the first timeliness and the real-time level corresponding to the response message satisfy the cache decision, the response message is stored.
The method according to claim 7 or 8, characterized in that, the method further includes:

Receive a query instruction from the second requester, the query instruction from the second requester being used to request the response message;

Send the response message to the second requester.
The method according to claim 9, characterized in that sending the response message to the second requester includes:

Obtain the first aging corresponding to the response message and the time when the response message is stored;

When the time difference between the current time and the time when the response message is stored is not greater than the first aging, send the response message to the second requester;

When the time difference between the current time and the time when the response message is stored is greater than the first aging, the request message is sent to the responder.
A timeliness guarantee method, characterized in that it is applied to the sending end, and the method includes:

The sending end sends a data frame to the receiving end; the data frame includes aging information, and the aging information of the data frame is used to indicate the remaining aging of the data frame;

The receiving end is configured to update the remaining aging of the data frame based on the link delay and the reception processing delay; the link delay is based on the starting time and the time when the link layer of the receiving end receives the data frame. The termination time of the link layer receiving the data frame is obtained; the reception processing delay is the time required by the protocol stack or the application layer to receive and process the data frame after the link layer receives the data frame. required time.
A timeliness guarantee method, characterized in that it is applied to the receiving end, and the method includes:

The receiving end receives a data frame from the sending end; the data frame includes aging information, and the aging information of the data frame is used to indicate the remaining aging of the data frame;

The receiving end obtains the link delay based on the starting time when the link layer of the receiving end receives the data frame and the ending time when the link layer of the receiving end receives the data frame;

Based on the link delay and the reception processing delay, the remaining time limit is updated; the reception processing delay is the time limit of the protocol stack or the application layer reception and processing after the link layer receives the data frame. The time required for the data frame.
The method according to claim 12, characterized in that the data frame carries a request message, and the request message includes a query instruction or a control instruction; the method further includes:

The receiving end executes the query instruction or the control instruction when determining that the request message is valid based on the remaining aging and the preset threshold.
The method according to claim 12 or 13, characterized in that the receiving end receives the data frame from the sending end, including:

The receiving end receives the data frame from the requesting party via at least one network device;

The at least one network device is configured to update the remaining aging of the data frame based on the transmission delay and the overall forwarding delay; the transmission delay is based on the starting time of the link layer of the network device receiving the data frame. and the termination time when the link layer of the network device receives the data frame; the overall forwarding delay is obtained based on the time required for the protocol stack or application layer of the network device to process the data frame.
An aging guarantee device, characterized in that the device includes:

A receiving unit, configured to receive a data frame, where the data frame includes aging information, and the aging information is used to indicate the remaining aging of the data frame;

A first processing unit configured to obtain the transmission delay based on the starting time when the link layer of the network device receives the data frame and the ending time when the link layer receives the data frame;

The second processing unit is configured to obtain the overall forwarding delay based on the time required for the protocol stack or application layer of the network device to process the data frame;

An update unit, configured to update the aging information based on the transmission delay and the overall forwarding delay;

A sending unit, configured to send the updated data frame.
The device according to claim 15, wherein the transmission delay is the time difference between the starting time and the ending time; the starting time is when the starting bit of the data frame is received. time, and the termination time is the time when the termination bit of the data frame is received;

The remaining timeliness in the updated data frame is the remaining timeliness in the data frame minus the difference between the transmission delay and the overall forwarding delay.
The device according to claim 15 or 16, characterized in that the overall forwarding delay includes a receiving processing delay and a sending processing delay; the updating unit is configured to:

Update the remaining aging of the data frame to the first aging to obtain the first data frame; the first aging is the remaining aging of the data frame minus the difference between the transmission delay and the reception processing delay ; The reception and processing delay is the time required for the protocol stack or the application layer to receive and process the data frame after the link layer receives the data frame; the remaining aging of the first data frame is the The first statute of limitations is mentioned;

Update the remaining aging of the first data frame to a second aging to obtain the updated data frame; the second aging is the difference between the first aging and the sending processing delay, and the sending The processing delay is the time required for the protocol stack or the application layer to send and process the first data frame before the link layer sends the updated data frame; the remaining aging of the updated data frame is the second aging period.
The device according to claim 17, characterized in that, before the sending unit sends the updated data frame, the device further includes a processing unit, the processing unit being configured to:

Based on the first aging, a processing method for the first data frame is determined; the processing method includes priority forwarding, normal forwarding, or discarding.
The device according to claim 18, characterized in that the processing unit is used for:

Based on at least one of the reliability level corresponding to the data frame and the real-time level corresponding to the data frame and the first timeliness, a processing method for the first data frame is determined.
The device according to any one of claims 15 to 19, characterized in that the data frame carries any one of a request message, a response message and an active notification message, and the request message includes a query instruction or a control instruction, The response message is a reply message generated in response to the query instruction or the control instruction.
The device according to any one of claims 15 to 20, characterized in that the data frame carries a response message generated by the responder in response to the query instruction of the first requester, and the device further includes a storage unit, and the storage Units are used for:

Store the response message.
The device according to claim 21, characterized in that the storage unit is used for:

When the first timeliness and the real-time level corresponding to the response message satisfy the cache decision, the response message is stored.
The device according to claim 21 or 22, characterized in that:

The receiving unit is configured to receive a query instruction from the second requester, and the query instruction from the second requester is used to request the response message;

The sending unit is configured to send the response message to the second requester.
The device according to claim 23, characterized in that the sending unit is used for:

Obtain the first aging corresponding to the response message and the time when the response message is stored;

When the time difference between the current time and the time when the response message is stored is not greater than the first aging, send the response message to the second requester;

When the time difference between the current time and the time when the response message is stored is greater than the first aging, the request message is sent to the responder.
An aging guarantee device, characterized in that the device includes:

A receiving unit, configured to receive a data frame from the sending end; the data frame includes aging information, and the aging information of the data frame is used to indicate the remaining aging of the data frame;

A processing unit configured to obtain the link delay based on the starting time when the link layer of the receiving end receives the data frame and the ending time when the link layer of the receiving end receives the data frame;

An update unit, configured to update the remaining aging based on the link delay and the reception processing delay; the reception processing delay is the protocol stack or the application after the link layer receives the data frame. The layer receives the time required to process the data frame.
The device according to claim 25, characterized in that the data frame carries a request message, and the request message includes a query instruction or a control instruction; the device further includes an execution unit, the execution unit is used for:

When it is determined that the request message is valid based on the remaining aging and the preset threshold, the query instruction or the control instruction is executed.
The device according to claim 25 or 26, characterized in that the receiving unit is used for:

receiving data frames from the requesting party via at least one network device;

The at least one network device is configured to update the remaining aging of the data frame based on the transmission delay and the overall forwarding delay; the transmission delay is based on the starting time of the link layer of the network device receiving the data frame. and the termination time when the link layer of the network device receives the data frame; the overall forwarding delay is obtained based on the time required for the protocol stack or application layer of the network device to process the data frame.
A chip system, characterized in that the chip system includes at least one processor and a communication interface, the communication interface is used to send and/or receive data, and the at least one processor is used to call at least one computer stored in a memory. Program, so that the device where the chip system is located implements the method according to any one of claims 1-14.
A computer-readable storage medium, characterized in that a computer program is stored in the computer-readable storage medium. When the computer program is run on one or more processors, it executes any of claims 1-14. method described in one item.
A communication system, characterized in that the system includes a sending end, a receiving end and a network device, the network device is used to perform the method according to any one of claims 1-10, and the sending end is used to The method according to any one of claims 11 is executed, and the receiving end adopts the method according to any one of claims 12-14.