KR20220027714A - A dds routing service system for providing processing a data priority control based on topic - Google Patents

Abstract

In accordance with an embodiment of the present invention, a data distribution service (DDS) routing service system includes a first LAN network including a first user device, a DDS middleware device and a DDS routing service device connected through a WAN network; and a second LAN network in a remote place including the same components as the first LAN network. The DDS routing service is set to: perform a communication processing function of routing DDS traffic data of the middleware device connected through the first local network to the middleware device connected to the second local network located in the remote place different from the first local network, through a broadband area; perform data management for data efficiency management processing using topic-based priority data control in response to the routed DDS traffic data, while providing a function of designating priorities by DDS topic in accordance with priority setting information; perform a process of controlling priorities of packet data in accordance with the determined priorities; determine and deliver the priority setting information by acquiring priority setting information designated by a user from the DDS routing service device; process priority queue management based on the determined priorities; and preferentially transmit packets corresponding to a priority queue. Therefore, the present invention is capable of minimizing latency and increasing routing efficiency.

Description

A DDS ROUTING SERVICE SYSTEM FOR PROVIDING PROCESSING A DATA PRIORITY CONTROL BASED ON TOPIC

The present invention relates to a routing service system for a data distribution service. More specifically, the present invention relates to a DDS routing service system that handles topic-based priority data control.

DDS (Data Distribution Service) defines OMG (Object Management Group) standard communication middleware, and discloses communication middleware that provides data-oriented publish-subscribe communication method to applications.

In particular, the DDS middleware provides efficient data distribution using the Publish/Subscribe communication technique in an environment where devices can freely participate/withdraw.

A characteristic of this DDS is that it is suitable for a ubiquitous environment in which a plurality of devices are dynamically linked to form a single network domain and exchange data frequently. DDS includes various functions such as publish/subscribe function, QoS control function, discovery function to find out the address of DDS participating node, and each middleware is equipped with computing resources such as processor and memory for such processing.

However, the middleware devices supporting the DDS standard are basically implemented based on a LAN (Local Area Network) connection, and thus communicate based on the Ethernet protocol, and there is a problem in that access is limited in an external network.

Therefore, in order to implement the current DDS middleware system so that it can be accessed through an external Internet network through WAN (Wide Area Network), all existing DDS network infrastructure and operation methods are changed to support WAN, and new DDS equipment and network There is a problem in having to build an infrastructure. This causes excessive cost, and it is inefficient because the existing DDS middleware system cannot be used, and thus it is difficult to apply to industrial sites.

In addition, there is a need to improve the inefficiency of the DDS middleware system itself. Since computing resources are limited, inefficient aspects such as throughput degradation, packet usage efficiency degradation, communication delay between threads, bandwidth management, etc. of DDS middleware defined by RTPS and OMG standards should be improved to efficiently operate the middleware system and routing service. do.

The present invention was devised to solve the above problems, and by processing the existing LAN-based DDS system traffic including the DDS support middleware device to be routed through a WAN-based network such as a normal Internet network, It is an object of the present invention to provide a DDS routing service system that enables an existing DDS system to perform DDS communication with other devices connected through a WAN without a separate infrastructure change.

Another object of the present invention is to provide a DDS routing service system capable of reducing network load, minimizing delay, and increasing routing efficiency by providing topic-based priority data control processing in providing a DDS routing service.

In addition, in order to improve the inefficiency of the DDS system, the present invention overcomes a decrease in throughput and a decrease in real-time communication due to a message size limitation, and prevents traffic loss and loss due to traffic flow control, thereby providing low latency. An object of the present invention is to provide a DDS routing service system that implements time and effectively enables real-time processing.

A system according to an embodiment of the present invention for solving the above problems, a first LAN network including a first user equipment, a DDS middleware device, and a DDS routing service device connected through a WAN network; and a second LAN network at a remote location having the same configuration as the first LAN network, wherein the DDS routing service comprises: DDS traffic of a middleware device connected through the first local network. Performs a communication processing function of routing data to a middleware device connected to a second local network located at a remote location different from the first local network through a wide area network, and in response to the routed DDS traffic data, topic-based priority It performs data management that performs data efficiency management processing using priority data control, but provides a function to specify a priority for each DDS topic according to priority setting information, and controls the priority of packet data according to the determined priority process, obtains the user-specified priority setting information from the DDS routing service device, determines and delivers the priority setting information, handles priority queue management based on the determined priority, and Packets are transmitted and processed first.

According to an embodiment of the present invention, existing LAN-based DDS system traffic including a DDS-supporting middleware device is processed to be routed through a WAN-based network such as a normal Internet network, It is possible to provide a DDS routing service system that enables the DDS system to perform DDS communication with other devices connected through a WAN.

In addition, according to an embodiment of the present invention, in providing the DDS routing service, it is possible to provide a DDS routing service system capable of reducing network load, minimizing delay, and increasing routing efficiency by providing topic-based priority data control processing. there is.

And, according to an embodiment of the present invention, in order to improve the inefficiency of the DDS system, it overcomes a decrease in throughput and a decrease in communication real-time due to a message size limitation, and prevents traffic loss and loss due to traffic flow control. , through which it is possible to provide a DDS routing service system that realizes low latency and effectively enables real-time processing.

1 is a conceptual diagram schematically illustrating an entire system according to an embodiment of the present invention.
2 is a block diagram illustrating a DDS routing service apparatus according to an embodiment of the present invention in more detail.
3 is a block diagram illustrating a data management unit according to an embodiment of the present invention in more detail.
4 is a block diagram illustrating a priority control unit according to an embodiment of the present invention in more detail.
5 is a flowchart for explaining the operation of the priority control unit according to an embodiment of the present invention in more detail.
6 is a block diagram illustrating a communication management unit according to an embodiment of the present invention in more detail.
7 and 8 are diagrams for explaining a detailed configuration of a traffic controller according to an embodiment of the present invention and a system operation according thereto.
9 is a diagram illustrating serialization of an RTPS message according to an embodiment of the present invention, and FIG. 10 is a diagram comparing serialization between an embodiment of the present invention and the prior art.
11 is a flowchart for explaining the operation of the packet processing unit according to the serialization unit processing according to an embodiment of the present invention.
12 is a flowchart illustrating an operation of an input/output pass-through activation unit according to an embodiment of the present invention.
13 is a flowchart illustrating an operation of a traffic controller according to an embodiment of the present invention.
14 is a flowchart illustrating in more detail a calculation process for calculating the delay time of the traffic control unit.

The following is merely illustrative of the principles of the invention. Therefore, those skilled in the art will be able to devise various devices that, although not explicitly described or shown herein, embody the principles of the present invention and are included within the spirit and scope of the present invention. Further, it is to be understood that all conditional terms and examples listed herein are, in principle, expressly intended solely for the purpose of enabling the concept of the present invention to be understood, and not limited to the specifically enumerated embodiments and states as such. should be

Moreover, it is to be understood that all detailed description reciting the principles, aspects, and embodiments of the invention, as well as specific embodiments, are intended to cover structural and functional equivalents of such matters. It should also be understood that such equivalents include not only currently known equivalents, but also equivalents developed in the future, i.e., all devices invented to perform the same function, regardless of structure.

Thus, for example, the block diagrams herein are to be understood as representing conceptual views of illustrative circuitry embodying the principles of the invention. Similarly, all flowcharts, state transition diagrams, pseudo code, etc. may be tangibly embodied on computer-readable media and be understood to represent various processes performed by a computer or processor, whether or not a computer or processor is explicitly shown. should be

The functions of the various elements shown in the figures including a processor or functional blocks represented by similar concepts may be provided by the use of dedicated hardware as well as hardware having the ability to execute software in association with appropriate software. When provided by a processor, the functionality may be provided by a single dedicated processor, a single shared processor, or a plurality of separate processors, some of which may be shared.

In addition, the clear use of terms presented as processor, control, or similar concepts should not be construed as exclusively referring to hardware having the ability to execute software, and without limitation, digital signal processor (DSP) hardware, ROM for storing software. It should be understood to implicitly include (ROM), RAM (RAM) and non-volatile memory. Other common hardware may also be included.

In the claims of the present specification, a component expressed as a means for performing the function described in the detailed description includes, for example, a combination of circuit elements that perform the function or software in any form including firmware/microcode, etc. It is intended to include all methods of performing the functions of the device, coupled with suitable circuitry for executing the software to perform the functions. Since the present invention defined by these claims is combined with the functions provided by the various enumerated means and in a manner required by the claims, any means capable of providing the functions are equivalent to those contemplated from the present specification. should be understood as

The above-described objects, features, and advantages will become more apparent through the following detailed description in relation to the accompanying drawings, whereby those of ordinary skill in the art to which the present invention pertains can easily implement the technical idea of the present invention. There will be. In addition, in the description of the present invention, if it is determined that a detailed description of a known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted.

Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a conceptual diagram schematically illustrating an entire system according to an embodiment of the present invention.

Referring to FIG. 1 , the entire system according to an embodiment of the present invention includes a first user device 10 , a DDS middleware device 300 , and a DDS routing service device 100 constituting a first LAN network 1000 . In addition, the first LAN network 1000 may be connected to the second LAN network 2000 of a remote location having the same configuration through a WAN network.

First, the user device 10 may be a user computing device that inputs a message through the DDS middleware device 300 or receives a subscription-processed message from the DDS middleware device 300 .

In addition, the DDS middleware device 300 publishes a message input from the user device 10 into the first LAN network 1000 or subscribes to a message received through the first LAN network 1000 to process the user device. It may be a typical DDS middleware device 300 that forwards to (10).

More specifically, the middleware device 300 according to an embodiment of the present invention provides a communication function using a Data Centric Publish Subscribe (DCPS) protocol and a RealTime Publish Subscribe (RTPS) protocol according to the standardized Dara Distribution Service (DDS) standard. can provide DCPS standardizes standardized user API and modeling, and RTPS standardizes communication protocol that enables interoperability between DDS vendors.

The DDS middleware device 300 is in charge of interfacing with the first user equipment 10 using the DCPS API of DDS, and receives a message publication/subscription request according to the request of the first user equipment 10, and receives the RTPS standard It performs transmission processing of publication message according to and reception processing of subscription message.

In addition, the DDS middleware device 300 may process a transmission event process and a retransmission event process required for message publication or subscription processing.

In addition, the DDS middleware device 300 may be connected to the first user device 10 through a communication interface, and packetize the message of the first user device 10 into an RTPS packet and transmit it to a communication interface, or a communication interface A process of restoring a message from an RTPS packet received through RTPS and transferring the message to the first user device 10 may be performed.

As described above, in an embodiment of the present invention, although not specifically illustrated, message information written in the first user device 10 may be transmitted to the message processing unit of the DDS middleware device 300 , and the transmitted message may be transmitted to the DDS middleware device It may be published and processed through the event processing unit of 300 , may be packetized through the packet processing unit, and transmitted to an external network through the communication interface unit.

In addition, when the message processing unit of the DDS middleware device 300 requests to receive the DDS subscription message from the first user device 10 , the packet received from the communication interface unit in the packet processing unit through the subscription message processing through the event processing unit is a subscription message. to be inversely transformed. In addition, the inversely transformed subscription message may be transmitted to the message processing unit through the event processing unit and output to the user device.

Here, in general, a network supported by the DDS middleware device 300 may be a local area network (LAN), and the LAN network may be a local network, and a region in which data transmission is possible may be limited.

That is, as described above, since the communicable area of the DDS middleware device 300 is limited to the local network, it communicates with the middleware device of the second LAN network 2000 in a remote location completely different from a protocol-based communication according to the DDS standard standard. This is an impossible state.

For example, free transmission and reception of traffic between the DDS middleware device 300 connected to the local network in the Daejeon area and the DDS middleware device 300 connected to the local network in the Seoul area is set to be impossible.

Accordingly, the DDS routing service apparatus 100 according to an embodiment of the present invention adds a DDS relay service node to each LAN network and transmits DDS traffic data through the relay service node in a wide area network (WAN) method. It can provide a traffic routing function that enables transmission and reception with

1, the WAN network connects the first LAN network 1000 and the second LAN network 2000, and the DDS routing service apparatus 100 is between the DDS middleware devices 300 between the areas. By efficiently relaying the generated message-related transmission traffic, it is possible to build a DDS service system supporting a broadband network or a long-distance communication network by simply setting up traffic routing without changing the infrastructure of the existing DDS middleware device 300 .

For efficient and compatible traffic data processing, the DDS routing service device 100 provides DDS vendor-neutral traffic processing, in particular, smart multicasting in the WAN network section, efficient and intelligent selective data compression, and data A traffic control process based on encryption and data serialization can be performed, which will be described in more detail later.

2 is a block diagram illustrating a DDS routing service apparatus according to an embodiment of the present invention in more detail.

Referring to FIG. 2 , the DDS routing service apparatus 100 according to an embodiment of the present invention includes a domain manager 110 , a setting manager 120 , a communication manager 130 , and a data manager 140 .

The DDS routing service apparatus 100 according to an embodiment of the present invention is implemented as an operation of software executed on a separate computer OS or is connected to a separate network equipment (router, modem, etc.) for a physical network connection. It may be implemented in hardware of The DDS routing service apparatus 100 may add one RS (Routing Servive) node to the DDS service system infrastructure connected to the existing DDS middleware device 300 of the first LAN network 1000, and through the RS node, Message subscription and publication traffic between DDS middlewares can be routed so that they are transmitted and received through WAN.

Accordingly, the DDS routing service apparatus 100 according to an embodiment of the present invention processes the DDS middleware device 300 to be connected and driven through a global communication network such as the general Internet, thereby providing a logical communication area of the DDS service, GDS. (Global Data Space) can be expanded.

More specifically, the domain management unit 110 collects and processes domain information for each middleware device 300 necessary for establishing the GDS relationship of each DDS middleware device 300 , and transfers the collected domain information to the communication management unit 130 . It may include one or more subsystems.

The communication management unit 130 builds a GDS node map based on the domain information collected by the domain management unit 110, and connects the DDS middleware devices 300 to each GDS node based on the GDS node map. Participant) can be managed.

In addition, the communication management unit 130 processes traffic bridging using the GDS node map, so that the DDS middleware device 300 connected to the first LAN network 1000 is an RS node of the second LAN network 2000 . can be processed so that it can be connected to other remote GDS nodes through do.

Meanwhile, the data management unit 140 may perform management service processing using routed traffic data for stable and efficient exchange processing of routed traffic data.

Here, the data management service may include at least one of a data encryption service through DTLS, a standard encryption communication protocol, a priority control service for a priority management function for each topic, a data topic compression service, and a selective multicasting processing service, This will be described in more detail with reference to FIG. 4 .

Meanwhile, the setting management unit 120 may store and manage setting information for system use. The user can update the setting information by inputting setting information in the form of a file or user input information, and the setting management unit 120 applies a setting information parser for this and the setting to apply the parsed setting information to each component. It may include an Applier. Preferably, the configuration information may be a file of a yaml (YAML Ain't Markup Language) data format, and may indicate a module to be applied and configuration information to be applied using scalar information, sequence information, and mapping information.

In addition, the setting management unit 120 may divide and manage setting information into four groups, and may be divided into a network group, a log group, a priority group, and a bridging group. Network group and bridging group setting information may be applied to the communication management unit 130 , log group information may be applied to all components, and priority group setting information may be applied to the data management unit 140 .

3 is a block diagram illustrating a data management unit according to an embodiment of the present invention in more detail.

Referring to FIG. 3 , the data management unit 140 according to an embodiment of the present invention includes a data encryption unit 141 , a topic compression unit 143 , a priority control unit 145 , and a multicasting processing unit 147 . .

The data encryption unit 141 applies Datagram Transport Layer Security (DTLS), which is a standard encryption communication protocol, to DDS traffic data to protect user data transmitted through a WAN from external attacks.

Here, DTLS is a protocol designed to safely transmit datagram-type content between applications, and can provide security services (integrity, authentication, information hiding, etc.) at the same level as SSL and TLS.

Accordingly, the data encryption unit 141, through DTLS encryption of the DDS traffic data, spying on data being transmitted in an intermediate network between the two endpoints of the DDS middleware devices 300 exchanging datagrams or counterfeiting, etc. behavior can be prevented in advance.

In addition, the topic compression unit 143 may analyze and learn topic information of each DDS traffic in real time to determine DDS topic traffic to process data compression in real time, and topic for the traffic for which topic compression is determined. By performing compression processing, it is possible to reduce the total amount of traffic to be routed and increase bandwidth efficiency. This will be described later in more detail with reference to FIGS. 4 and 5 .

In addition, the priority control unit 145 may provide a function of designating a priority for each DDS topic, and may perform a process of controlling the priority of traffic according to the determined priority. Priority can be specified through Nme Pattern Matching, etc. In particular, in situations such as an explosion of data, the processing priority for a specific topic is set so that the minimum communication bandwidth for each DDS topic can be secured. there is.

Meanwhile, the multicasting processing unit 147 may implement a multicasting service of traffic that is not basically allowed in a WAN environment through a routing service node (RS node). The multicasting processing unit 147 may provide a multicasting service for processing global multicasting of a subscription/publish message to one or more DDS participant middleware devices 300 connected to the RS node.

Also, the multicasting processing unit 147 may determine whether to multicast by analyzing the subscription/publishing relationship of the DDS topic from the traffic information. Accordingly, even unicast traffic received through the WAN may be changed to multicast traffic in the case of a message issued from a specific middleware device 300 and multicasting may be processed by the receiving GDS node. Accordingly, the multicasting processing unit 147 performs selective multicasting to a plurality of DDS middleware devices 300 corresponding to domain participants registered in the GDS map, based on the analysis of the subscription/publishing relationship information of the DDS topic of the traffic information. can be done

4 is a block diagram illustrating a priority control unit according to an embodiment of the present invention in more detail.

Referring to FIG. 4 , the priority control unit 145 according to an embodiment of the present invention provides a function to designate a priority for each DDS topic, and performs a process of controlling the priority of traffic according to the determined priority. can do. Priority can be specified through Nme Pattern Matching, etc. In particular, in situations such as an explosion of data, the processing priority for a specific topic is set so that the minimum communication bandwidth for each DDS topic can be secured. there is.

To this end, the priority control unit 145 according to an embodiment of the present invention includes a priority setting information registration unit 1451 , a priority determination unit 1453 , a priority queue processing unit 1455 , and a packet input/output unit 1457 . include

The priority setting information registration unit 1451 obtains the user-specified priority setting information from the setting management unit 120 , and transmits the obtained priority setting information to the priority determination unit 1453 .

In addition, the priority determining unit 1453 analyzes packet data of traffic data routed through the packet input/output unit 1457 on a topic-based basis, and determines whether to perform priority control processing based on the priority setting information.

The priority determiner 1453 may identify a topic packet capable of designating a priority among packet data, determine priority information corresponding to the identified topic packet, and transmit it to the priority queue processing unit 1455 .

The priority queue processing unit 1455 may manage a packet data queue (a transmission queue) to be output to the packet input/output unit 1457 , and in particular, a topic packet to which priority information is specified is registered in the priority queue, Unordered packets can be registered in the general queue.

The packet input/output unit 1457 transmits the received packet to the priority determiner 1453 to request prioritization, and the topic packets of the priority queue transmitted through the priority queue processing unit 1455 are packets of the general queue. It is possible to select data to be transmitted preferentially over other data, and to change the data transmission order based on the selection process.

Accordingly, when a packet to be transmitted is acquired in the routing service, the priority based on the topic may be predetermined, priority queue management based on the determined priority is processed, and packets corresponding to the priority queue are prioritized. By allowing transmission to be processed as , the transmission bandwidth and quality can be maintained even in a network overload condition or data explosion condition.

More specifically, the priority setting information registration unit 1451 may generate a data queue list based on the priority setting information, and the generated data queue is determined by the priority determining unit 1453 and the priority queue processing unit 1455 . can be transmitted as When there is no priority setting information, only one priority queue having only the smallest priority value may be created.

In addition, the priority determining unit 1453 may calculate a probability of accessing each data queue based on topic information and priority setting information of the packet, and determine whether to designate a priority queue according to the probability value.

More specifically, for example, the priority setting information may include type information and level information.

The type information includes a prioritization rule, for example, may include criteria type information for determining priority, such as a topic name (by topic name).

The level information may include a group level for each pattern corresponding to the prioritization rule. The higher the level at which the pattern is assigned, the higher the priority can be determined.

Such type information and level information may be displayed as character strings, type information may be designated as a separator setting, and level information may be designated according to an arrangement of {pattern, value} objects. The table below is an example of setting information including type information and level information.

type information Default: “none”,
List: [ “none”, “by_topic_name” ] level information levels:
- patterns: [ "Urgent*" ]
rate: 100
- patterns: [ "Normal*", "Norm" ]
rate: 50

As shown in Table 1, the topic type of the packet to be classified by priority may be a topic name (by_topic_name), and when "Urgent" is included in the name pattern, a priority level of 100 is specified, and the name pattern is When "Normal" is included or "Norm", a priority level of 50 may be designated. In this case, a packet including "Urgent" in the name type of the topic can be assigned a priority and its queue list at a level of 100, and a packet containing "Normal" or "Norm" can be assigned a level of 50. Priorities and their cue lists can be assigned.

In addition, the priority determining unit 1453 may calculate the probability P_i of accessing the i-th data queue Q_i among the n packets by comparing the mutual levels between packets, and assigning a priority queue for each packet based on the calculated P_i can decide whether

More specifically, the operation on P_i may be described by Equation 1 below.

Here, V_total may be the sum of all priority level values from the priority queue list registered by the user as priority setting information.

In addition, Vi is a numerical expression of the value of the i-th priority level, and may be set by the user, such as the rate 100, rate 50, and the like.

P_i represents the probability that the current packet accesses the data queue corresponding to the i-th priority.

P_total is the sum of the probability of data access to all priority queues in the priority queue list, and may always be 1.

Accordingly, the priority control unit 145 may initially update V_total and, if priority setting information exists, update P_i and generate Q_i based thereon.

5 is a flowchart for explaining the operation of the priority control unit according to an embodiment of the present invention in more detail.

Referring to FIG. 5 , the priority determining unit 1453 according to an embodiment of the present invention may classify packets loaded from the packet input/output unit 1457 and register them in the data queue. Based on this, each packet You can determine the priority level. However, among the DDS RTPS packet and the RS packet, the packet to which priority can be applied may be a DATA packet among the DDS RTPS packets. there is.

Accordingly, FIG. 5 is a flowchart for explaining a case in which priority control for a topic packet is processed, and a general data queue that is not a priority packet may have the lowest priority value.

When the priority control process is performed, first, the priority control unit 145 calculates C_current, which is a data queue selection reference value at the time of data transmission (S1501).

The data queue selection reference value C_current may be calculated through Equation 2 below.

Here, R_current is the value of a random number generated when the packet accesses the current data queue, and the maximum value of the number returned when the random number generation function is used is R_max, for example, 32647 (hexadecimal: 0x7fff). In addition, R_total may be a value obtained by adding all random numbers assigned to all packets currently being processed.

Then, the priority control unit 145 calculates the access probability P value of the current packet to the highest priority data queue Q_i as P_i based on the priority type information and the level information (S1502), and the C_current value is higher than P_i It is determined whether it is less than or equal to (S1503).

If less than or equal to, the priority control unit 145 may select the packet of Q_i as a packet of the data queue to be output prior to the current data queue Q_current (S1511).

If less than or equal to, the priority control unit 145 subtracts the value of P_i from C_current, and sets a probability value corresponding to the next priority queue in P_i ( S1505 ).

Thereafter, the priority control unit 145 checks whether the next level information exists in the setting information (S1507).

If the next level information exists, the priority control unit 145 processes again from step S1502.

However, when the next level information does not exist, the priority control unit 145 selects a packet of the current data queue Q_current as an output packet (S1509).

6 is a block diagram illustrating a communication management unit according to an embodiment of the present invention in more detail.

Referring to FIG. 6 , the communication management unit 130 according to an embodiment of the present invention configures a communication interface, and includes an endpoint socket management unit 131 , a bridge processing unit 133 , a traffic control unit 135 , and a GDS management unit 137 . ) is included.

The endpoint socket management unit 131 handles creation, connection, and destruction management of endpoint sockets for exchanging DDS traffic routed through the WAN network. The DDS middleware devices 300 connected to each LAN network through the endpoint socket connection may exchange traffic data with each other through the WAN network.

In addition, the bridge processing unit 133 may perform bridging processing of traffic data, and according to the bridging processing, the DDS domain participants connected to each GDS node can communicate in the same way as LAN communication. do.

Bridge processing is processed in the MAC layer among the data link layers, and it can handle packet transmission between the data link layers between two segments. there is. The bridging process may perform a function of filtering or forwarding the traffic by examining the MAC address, looking at the source address and the destination address of the packet managed by the data link layer, determining whether the packet should be passed through or not. Accordingly, since the DDS routing service apparatus 100 according to an embodiment of the present invention includes a bridge function, it may also be referred to as a DDS routing service apparatus.

The GDS management unit 137 builds a GDS node map based on the domain information collected by the aforementioned domain management unit 110, and stores and manages mapping of the DDS middleware devices 300 as each domain participant based on the GDS node map. can do.

Meanwhile, the traffic control unit 135 may perform a process of converting an RTPS standard message transmitted and received through the communication management unit 130 into a communication protocol packet such as UDP in order to ensure interoperability between DDS products, and this conversion process can perform the serialization process of serializing the message requested to be published in the form according to the RTPS standard, and the process of minimizing the delay time. This will be described in more detail with reference to FIGS. 7 to 14 .

7 is a block diagram illustrating a detailed configuration of a traffic control unit and a system operation according thereto according to an embodiment of the present invention.

Referring to FIG. 7 , the traffic control unit 135 according to an embodiment of the present invention includes a traffic control activation determination unit 1355, a packet processing unit 1351, an event processing unit 1352, and a message processing unit 1353, The packet processing unit 1351 may be connected to an external network through the communication interface unit 1354 , and the message processing unit 1353 publishes and processes a message input from the first user device 10 or subscribes to a message received from the network. It may be processed and transmitted to the first user device 10 .

The traffic control activation determiner 1355 may determine whether to activate the operation of the traffic control unit 135 according to the configuration information identified by the configuration manager 120 . The configuration information may include a related traffic control reference variable and a delay variable, which will be described later in response to traffic control.

The message processing unit 1353 is responsible for interfacing with the first user device 10 using the DCPS API of DDS, and receives a message publication/subscription request according to the request of the first user device 10, and conforms to the RTPS standard. It performs transmission processing of published message and reception processing of subscription message.

In addition, the event processing unit 1352 may process a transmission event process and a retransmission event process required for the message publication or subscription processing of the message processing unit 1353 .

On the other hand, the packet processing unit 1351 may be connected to the communication interface unit 1354, packetize the message into an RTPS packet and transmit it to the communication interface unit 1354, or restore the message from the RTPS packet to the event processing unit 1352 Forwarding processing can be performed.

As described above, in an embodiment of the present invention, the message information written in the first user device 10 may be transmitted to the message processing unit 1353, and the transmitted message is published and processed through the event processing unit 1352 to be processed by the packet processing unit ( 1351 ) and may be transmitted to an external LAN or a WAN network through traffic routing through the communication interface unit 1354 .

Then, when the message processing unit 1353 receives a request to receive the DDS subscription message from the first user device 10 , the packet processing unit 1351 receives it from the communication interface unit 1354 through the subscription message processing through the event processing unit 1352 . The received packet is inversely converted into a subscription message. In addition, the inversely transformed subscription message may be transmitted to the message processing unit 1353 through the event processing unit 1352 and output to the first user device 10 .

In particular, the packet processing unit 1351 according to an embodiment of the present invention converts an RTPS standard message transmitted and received through the communication interface unit 1354 into a communication protocol packet such as UDP to ensure interoperability between DDS products. may be performed, and this conversion process may include a serialization process of serializing a message requested to be published in a form according to the RTPS standard.

And, in the serialization process, the packet processing unit 1351 according to an embodiment of the present invention can eliminate bandwidth waste through a real-time BATCHING process and ensure real-time performance.

More specifically, for example, in RTPS, one user message is basically configured to be serialized into one RTPS message. Accordingly, when the first user device 10 requests to publish 100 messages, 100 RTPS messages may be generated and transmitted to the network.

However, due to the characteristics of the network device, frequent I/O caused by a large number of packets generated within a short period of time causes performance degradation. In addition, when converting user data into network packets, space for expressing metadata and headers of each protocol such as Ethernet, IP, UDP, and RTPS is added to the message. Bandwidth is wasted.

Accordingly, in order to solve the performance degradation due to frequent I/O and the wastage of bandwidth required for expressing protocol metadata and headers, and at the same time to ensure real-time performance, the packet processing unit 1351 according to the embodiment of the present invention includes: A serialization process capable of batching multiple messages up to the maximum allowable byte limit of the packet in the RTPS sub-message may be processed, and one or more message buffers may be included for this.

In addition, when the packet processing unit 1351 according to an embodiment of the present invention performs start and end processing of each event processed by the event processing unit 1352, a delay caused by communication between threads and a delay time caused by a state transition In order to minimize this, an input/output pass-through path that processes a message publication or subscription process with a single thread can be activated. In general, the delay time can be minimized.

In addition, the packet processing unit 1351 according to an embodiment of the present invention may set a maximum bandwidth that prevents loss during traffic control, which is performed by performing transmission standby processing through a delay time calculation according to packet transmission parameters. can be adjusted.

8 is a block diagram illustrating a detailed configuration of a packet processing unit and a system operation according thereto according to an embodiment of the present invention.

Referring to FIG. 8 , the packet processing unit 1351 according to an embodiment of the present invention includes an input/output pass-through activation unit 1351a, a serialization unit 1351b, a traffic delay control unit 1351c, and a transceiver 1351d. .

First, the packet processing unit 1351 may use UDP as a transport layer protocol of the RTPS, and may encapsulate the middleware internal data and user data generated through the middleware into an RTPS message. Since RTPS uses UDP as the transport layer, RTPS messages can be encapsulated back into UDP datagrams.

The serializer 1351b may serialize the RTPS message for encapsulating the RTPS message into a UDP datagram.

9 is a diagram illustrating serialization of an RTPS message according to an embodiment of the present invention, and FIG. 10 is a diagram comparing serialization between an embodiment of the present invention and the prior art.

Referring to FIG. 9 , the RTPS message may specifically include an RTPS header and one or more RTPS submessage data, and the RTPS header includes an arbitrary value (Magic Value), a protocol version (Protocol Version), and a vendor ID (Vendor ID). and publisher identification information (GUID-Globally Unique Identifier) that publishes the message. The DDS physically performs communication using an IP address and a UDP port through the communication interface unit 1354, but logically it is defined so that the counterpart can be identified with a GUID prefix.

And, the RTPS sub-message data may include sub-message header information and sub-message body information. The sub-message header information may include sub-message type information and size information. The sub-message body information may include actual data to be expressed by the message.

The sub-message type information may be classified as DATA, DATA_FRAG, GAP, ACKNACK, HEARTBEAT, HEARTBEAT_FRAG, PAD, INFO_SRC, INFO_DST, INFO_TS or INFO_REPLY, and may indicate the properties of actual data included in each sub-message body. .

And, referring to FIG. 10(A), basically, in the prior art, one user message is serialized into one RTPS message. Therefore, when the user publishes 100 messages, 100 RTPS messages are generated and transmitted to the network. Due to the characteristics of network devices, frequent I/O caused by a large number of packets generated within a short period of time causes performance degradation. In addition, when converting user data into network packets, space for expressing metadata and headers of each protocol such as Ethernet, IP, UDP, and RTPS is added to the message. Bandwidth is wasted.

Accordingly, the serializer 1351b according to the embodiment of the present invention, as shown in FIG. 10B, batches the RTPS sub-message constituting the RTPS message up to the maximum byte limit allowed for the packet. ) can be processed. Therefore, if the user message is small enough, a plurality of user messages can be serialized into one RTPS message.

To this end, the serializer 1351b may include a separate message buffer (not shown) for message batching. In order to batch messages, enough messages must be accumulated in the message buffer.

Accordingly, the serializer 1351b according to an embodiment of the present invention transmits a message immediately when the first user device 10 requests a message publication faster than the network transmission speed in order to accumulate enough messages in the message buffer. It is determined as an impossible message and can be processed to accumulate in the message buffer. In addition, the serializer 1351b may secure time for the message to accumulate in the message buffer by forcibly delaying the message publication request received from the user device 200 .

In particular, the DDS standard defines a delay allocation (LATENCY_BUDGET) parameter as a QoS parameter. The delay allocation parameter can be applied to the first user device 10 of the publishing side, and is defined as a numerical value that merely expresses the urgency of data communication, but the actual meaning can be arbitrarily assigned by the implementer. Accordingly, the serializer 1351b according to an embodiment of the present invention may redefine the delay allocation (LATENCY_BUDGET) parameter as the maximum delay time of message transmission for arranging the RTPS message.

Accordingly, the serializer 1351b according to an embodiment of the present invention forcibly delays the message publication request received from the first user device 10 during the maximum delay time of message transmission based on the delay allocation parameter, and processes the requested publication message. is accumulated in the message buffer, and when the delay time has elapsed, the accumulated messages are batch-processed to form one serialized RTPS merge message, and the configured RTPS merge message is converted into a communication packet through the transceiver 1351d and the communication interface unit (1354) can be output.

Since this RTPS merge message follows the RTPS standard defined in DDS as it is, interoperability is not affected, and the receiver can acquire serialized data from the start point to the end point of the messages included in the RTPS merge message, respectively. Real-time batch transmission and reception processing becomes possible.

Accordingly, the serialization unit 1351b according to an embodiment of the present invention can solve the aforementioned performance degradation due to frequent I/O and waste of bandwidth required for expressing protocol metadata and headers, and at the same time guarantee real-time performance. can

11 is a flowchart for explaining the operation of the packet processing unit 1351 according to the processing of the serialization unit 1351b according to an embodiment of the present invention.

Referring to FIG. 11 , when an event of the event processing unit 1352 is generated and delivered (S101), the serializer 1351b according to an embodiment of the present invention determines whether it is a message publication event (S103).

In the case of a message publication event, the serialization unit 1351b assigns a sequence having the same GUID to the publication message and inserts the sequence into the message buffer (S109).

For example, a sequence assigned to a publication message may be a serial number such as 1, 2, 3, and all messages inserted into the message buffer may be matched to the same publisher identifier (GUID).

Then, the serializer 1351b determines whether the message buffer is full (S111), and if it is full, performs batch processing of the buffered messages (S113). If it is not full, the publication event may be processed by waiting until a certain delay allocation cycle time.

Here, the serializer 1351b may perform a process of including a plurality of submessages to which a serial number sequence is assigned to one RTPS message matched with the same publisher identifier (GUID) for buffered message batching processing. .

Then, the serializer 1351b transmits the batched message to the transceiver 1351d, and the transceiver 1351d processes the packetized message and transmits it to an external network through the communication interface unit 1354 (S115).

Meanwhile, according to an embodiment of the present invention, as described above, a delay allocation (LATENCY_BUDGET) QoS parameter may be set.

Accordingly, when it is confirmed that the event generated in step S103 is not a message publication event, the serializer 1351b determines that it is a delay allocation cycle event, and checks whether a message waiting for more than the delay allocation time exists in the message buffer. (S105).

If there is a message waiting for the delay allocation time, the serialization unit 1351b performs batching processing (S113) and transmission processing (S115) of the messages buffered so far.

However, if there is no message waiting longer than the delay allocation, the serializer 1351b may re-schedule the periodic event according to the delay allocation ( S107 ), so that there is no data delayed more than the delay allocation time.

Accordingly, the batching processing of the serialization unit 1351b according to the embodiment of the present invention can guarantee real-time, and in particular, through the setting of the delay allocation (LATENCY_BUDGET) QoS parameter, the maximum within the delay limit guaranteed by the specific parameter. Message throughput can be secured.

Meanwhile, referring to FIG. 8 again, the packet processing unit 1351 according to the embodiment of the present invention includes an input/output pass-through activation unit 1351a.

The routing service apparatus 100 and the middleware device 300 according to an embodiment of the present invention may be divided into a plurality of processing units in order to reduce the complexity of implementing complex DDS functions, and each processing unit performs flow linkage with other processing units. Except for some logic for , most of the logic can be driven independently of other processing units. Accordingly, the routing service apparatus 100 and the middleware device 300 according to an embodiment of the present invention may include their own processors in each processing unit, and each processor processes each process thread so that several tasks are performed at the same time. In this way, it is possible to respond to a large number of message publication/subscription requests.

However, a delay occurs when the flow of processing is changed from one processing unit to the next processing unit. This may be caused by a delay caused by inter-thread communication with the next processing unit that occurs at the start and end of event delivery, and a delay until the corresponding thread is restarted when the next processing unit's thread is in the waiting state.

In order to minimize the delay, the input/output pass-through activation unit 1351a according to an embodiment of the present invention directly processes the task without creating a thread to start or end event transfer between each processing unit through thread driving of a single processing unit. The occurrence of unnecessary delay time can be minimized, and it can be processed ON or OFF by determining whether the input/output pass-through function is activated.

For example, when I/O pass-through is enabled, parallel processing becomes impossible because a message is processed until the final processing using a thread of one processing unit, and as a result, processing performance of a large amount of messages may be reduced. Accordingly, the input/output pass-through activation unit 1351a according to an embodiment of the present invention may dynamically change whether to activate the input/output pass-through in order to optimize both throughput and delay time.

12 is a flowchart for exemplarily explaining the operation of the input/output pass-through activation unit 1351a according to an embodiment of the present invention.

Referring to FIG. 12 , the input/output pass-through activation unit 1351a according to an embodiment of the present invention optimizes both the throughput and the delay time. By comparing , it is possible to dynamically change whether input/output pass-through is activated.

More specifically, first, the input/output pass-through activation unit 1351a accumulates and records transmission/reception time information of the RTPS packet (S201).

Then, the input/output pass-through activation unit 1351a determines whether the time recording is measured 32 times or more ( S203 ).

Here, the number of times recorded may be different depending on the network environment.

Then, the input/output pass-through activation unit 1351a determines whether the measured average value of the time difference between packets of the RTPS packets is within a preset transmission/reception processing time of one RTPS packet ( S205 ).

If the time difference average is within the pre-set transmission/reception processing time of one RTPS packet, it may be determined that the number of current packets processed through input/output pass-through is large. The pass-through activation unit 1351a may deactivate the input/output pass-through function (S207).

On the other hand, if the time difference average value exceeds the preset transmission/reception processing time of one RTPS packet, the serial message processing can minimize the delay time, so the input/output pass-through activation unit 1351a activates the input/output pass-through function (S209) ).

In this way, the input/output pass-through activation unit 1351a according to the embodiment of the present invention can minimize the delay time according to the real-time transmission situation of the message. In particular, when processing a large number of messages, each processing unit processes the message in parallel Since it is possible to minimize the delay time, it is expected that I/O pass-through is disabled, and the overhead of event delivery start/end is expected to be large when processing a small amount of messages. there will be

Meanwhile, referring to FIG. 8 again, the packet processing unit 1351 according to an embodiment of the present invention may include an input/output traffic delay control unit 1351c.

The transceiver 1351d may packetize the data processed by the serializer 1351b and transmit the packet to an external network. However, when the bandwidth of the network interface of the communication interface unit 1354 is greater than the bandwidth of the actual network, all packets corresponding to the excess of the bandwidth of the actual network may be lost.

In order to recover the lost packet, the transceiver 1351d may start a retransmission process. However, since the retransmission process is also an act of transmitting packets to the network, some retransmission packets may also be lost as much as bandwidth excess occurs in the retransmission process, and a vicious cycle of retransmitting some lost retransmission packets causes deterioration of communication performance. .

Accordingly, the traffic delay control unit 1351c according to an embodiment of the present invention can connect between the serialization unit 1351b and the transceiver 1351d, so that the transmission bandwidth can be constantly controlled through the transmission time delay, Packet loss due to excess bandwidth can be prevented. This maximum bandwidth allowance may vary depending on the actual network environment and may be predetermined according to user settings.

13 is a flowchart for explaining the operation of the traffic delay control unit 1351c according to an embodiment of the present invention.

Referring to FIG. 13 , when serialized message data is transmitted from the serialization unit 1351b ( S310 ), the traffic delay control unit 1351c according to an embodiment of the present invention determines whether the current time is within a delay time according to a preset bandwidth. do (S303).

Then, the traffic delay control unit 1351c transmits the message to the transceiver 1351d if it is within the allowable amount (S305), and if it exceeds the allowable amount, processes the transmission delay for a certain period of time (S307), and delays the transmission of the delayed message After a time, it may be transmitted to the transceiver 1351d.

More specifically, in step S303, the traffic delay control unit 1351c according to an embodiment of the present invention may determine whether the current time point is within a delay time according to a preset bandwidth using Equation 3 below. .

Equation 3 as described above shows a process of calculating the time T_open during which packet transmission is possible when n packets are transmitted. You can decide whether or not to delay.

More specifically, T_open indicates a time during which packet transmission is possible, and when T_current is earlier than T_open, packet transmission may be delayed.

T_current may represent the current time, and a value representing the UNIX Epoch Timestamp with nanosecond resolution may be exemplified. For example, T_current corresponding to 16:30 on October 1, 2019 may have a value of 1,569,915,000,000,000,000.

And, B may be a value representing the maximum bandwidth value of the network interface used by the middleware device 300 in bits per second (bps). The maximum bandwidth value may be detected by the traffic delay control unit 1351c by identifying it from the communication interface unit 1354, or may be separately designated by the user.

And, 10^9 / B represents a bit slice, and may mean nanoseconds required for the bandwidth of a network device to transmit 1 bit.

In addition, L_i may indicate the size of the i-th packet, and since the packet size Li is a byte unit, a value obtained by multiplying the packet size by 8 to integrate the packet size unit into bits may be defined to be cumulatively summed.

Referring to Equation 1 proposed in this way, the traffic delay controller 1351c determines how much bit slices divided in nanoseconds are used when Tx traffic occurs due to packet transmission occurring within a preset maximum bandwidth. By calculating , it is possible to calculate the time T_open during which packet transmission is possible.

For example, if the currently measured T_current is smaller than the last calculated T_open, the traffic delay control unit 1351c may delay transmission for a delay time equal to the T_open - T_current value.

14 is a flowchart illustrating in more detail an operation process for calculating the delay time of the traffic delay control unit 1351c.

Referring to FIG. 14 , the traffic delay control unit 1351c according to an embodiment of the present invention inputs an initial T_open of 0 and updates T_current to a current value (S401).

Then, the traffic delay control unit 1351c determines whether T_current is greater than T_open (S403).

If T_current is smaller than T_open, the traffic delay control unit 1351c determines whether a difference between T_open - T_current values is 1 ms or less (S405).

If the difference between T_open - T_current is greater than 1 ms, the traffic delay controller 1351c determines whether T_open is less than T_current (S407).

If T_open is not smaller than T_current, the traffic delay control unit 1351c processes transmission standby and updates the T_open value to T_current (S409).

Meanwhile, when T_current is greater than T_open in step S403 , the traffic delay control unit 1351c determines whether a difference between the values of T_current - T_open is 1 ms or less ( S411 ).

If T_open is smaller than T_current or the difference between T_current and T_open is not less than 1 ms in step S407, T_current is updated again (S413) and T_open is updated again (S415).

According to such processing, the T_open value and the T_current value may be adjusted so that transmission standby does not occur too often. In particular, when the current time has elapsed more than 1 millisecond from the last packet transmission time, the T_open value may be updated to the T_current value so that the transmission standby processing flow does not occur.

Meanwhile, referring back to FIG. 8 , the packet processing unit 1351 according to an embodiment of the present invention includes a transceiver 1351d, and the transceiver 1351d includes a serialization unit 1351b and a traffic delay control unit 1351c. The received message is packetized and transmitted to an external network through the communication interface unit 1354, or an external packet is received and delivered to the serializer 1351b, and the deserialized subscription message is transmitted through the message processing unit 1353. It may be processed to be transmitted to the first user device 10 .

Through such a configuration, the routing service apparatus 100 according to an embodiment of the present invention may provide message batching processing, input/output processing pass-through processing, and traffic delay control processing capable of maintaining real-time performance.

The above-described method according to various embodiments of the present invention may be implemented as a program and provided to each server or device while being stored in various non-transitory computer readable media. Accordingly, the user terminal 100 may access the server or device to download the program.

The non-transitory readable medium refers to a medium that stores data semi-permanently, rather than a medium that stores data for a short moment, such as a register, cache, memory, and the like, and can be read by a device. Specifically, the above-described various applications or programs may be provided by being stored in a non-transitory readable medium such as a CD, DVD, hard disk, Blu-ray disk, USB, memory card, ROM, and the like.

In addition, although preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific embodiments described above, and the technical field to which the present invention belongs without departing from the gist of the present invention as claimed in the claims In addition, various modifications are possible by those of ordinary skill in the art, and these modifications should not be individually understood from the technical spirit or perspective of the present invention.

Claims (7)

a first LAN network including a first user equipment connected through a WAN network, a DDS middleware device, and a DDS routing service apparatus; And a DDS (Data Distribution Service) routing service system comprising a second LAN network at a remote location having the same configuration as the first LAN network,
The DDS routing service,
Performs a communication processing function of routing DDS traffic data of a middleware device connected through a first local network to a middleware device connected to a second local network located in a remote location different from the first local network through a wide area network,
In response to the routed DDS traffic data, performing data management that performs data efficiency management processing using topic-based priority data control,
Provides the function to specify the priority of each DDS topic according to the priority setting information, and performs the process of controlling the priority of packet data according to the determined priority,
It acquires the user-specified priority setting information from the DDS routing service device, determines and delivers the priority setting information, processes the priority queue management based on the determined priority, and transmits the packets corresponding to the priority queue first to be processed
DDS Routing Service System. The method of claim 1,
The priority setting information includes priority determination rule information and priority information for each pattern corresponding to the priority determination rule
DDS Routing Service System. 3. The method of claim 2,
The priority determination rule information includes topic type information, and the priority information for each pattern includes priority level information for each specified string pattern.
DDS Routing Service System. The method of claim 1,
The priority control is
It processes priority queue management based on the determined priority and prioritizes transmission and processing of packets corresponding to the priority queue.
DDS Routing Service System. The method of claim 1,
The priority packet is a topic packet corresponding to a user-defined topic among the DATA packets of the DDS RTPS packet.
DDS Routing Service System. The method of claim 1,
The priority control includes calculating a priority probability value P_i of a current packet corresponding to the highest priority data queue Q_i based on priority type information and level information obtained from the priority setting information, and the P_i probability It compares the value and the current data queue selection standard value C_current to determine whether or not to output priority queue packets.
DDS Routing Service System. The method of claim 1,
The communication processing, but controlling the traffic for performing the message-based control processing of the traffic data,
The traffic control is
The message request received from the user device is transferred to the routing service device, the message received from the routing service device is serialized, and the packet is transmitted to the network.
The packet processing is
Serializes the message requested to be published in a format according to the RTPS (Real Time Publish Subscribe) standard, but batches a plurality of messages accumulated in the message buffer into a sub-message of one RTPS message.
DDS Routing Service System.

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