JP2005278215A - Communication system and communication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To preferentially perform communication processing of data with real time nature without delay in a communication system using a protocol. <P>SOLUTION: Information in the protocol header of data to be transmitted and received is considered as priority decision information for deciding whether or not transmission/reception processing is preferentially performed and the information to be preferentially processed is registered, managed and stored as priority data information in combination of the priority decision information. In the transmission/reception processing of the data, the priority decision information is taken out from transmission/reception data and whether or not it is the data registered as the priority data information is decided. In the case of the registered data, the transmission/reception processing is performed to the data in preference to data which is not registered. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a communication system and a communication method. Specifically, there are data that requires real-time characteristics suitable for non-delayable communication, such as multimedia data such as voice and image data, and urgent plant data, and other data that allows some delay. The present invention relates to a mixed communication system and communication method.

DARPA (Defence Advanced Research Project Agency) protocol TCP
(Transmission Control Protocal) / IP (Internet Protocol) and ISO (International
In a communication system using a protocol such as the Standards Organization (OSI) Open Systems Interconnection (OSI) protocol, data that is allowed to be delayed and data that is not allowed to be delayed (multimedia, real-time data such as plant data is required. Construction of a communication system capable of realizing communication that maintains real-time characteristics even when data is coexisted is demanded by end users. As a method of this type, for example, as described in Japanese Patent Laid-Open No. 4-180425, there is a method of performing priority control on the order of received data processing according to information associated with a network address of a communication partner terminal and a communication partner process. Further, as described in, for example, Japanese Patent Laid-Open No. 63-287231, there is a method for determining whether or not the data is preferentially processed by paying attention to the data length of the data received in the internetwork relay device.

  The prioritized control of the conventional communication system is not considered to perform the priority control for each communication program of each application using the same protocol, or to perform the priority control by the communication partner even for the same communication program.

  Further, the priority control of the conventional communication system does not take into consideration that the priority processing level corresponding to the real-time property is set for each data handled by the application communication program.

  Furthermore, conventionally, there has been a problem that the usability is poor in designing and constructing a system.

  Further, conventionally, consideration has not been given to priority control in a communication system configured by connecting a plurality of networks with terminals that communicate with each other through an inter-network relay device.

  In addition, the priority control of the conventional communication system is a congestion state of the communication network due to transmission timeout at the data transmission terminal and frequent retransmission because the transmission or reception processing of non-priority data is interrupted when priority data continues. No consideration is given to prevention of disconnection or disconnection of logical lines.

  An object of the present invention is to realize priority control without providing communication restrictions for each data handled by an application communication program.

  Another object of the present invention is to realize priority control in a communication system including an inter-network relay device.

  Another object of the present invention is to prevent congestion of a communication network and prevention of disconnection of a logical line without causing starvation in low priority data even when high priority data is continuously processed. It is.

  A feature of the present invention for achieving the above object is that, in a communication system, the order of data transmission or reception processing is determined for each data from priority determination information in transmission or reception data and pre-registered priority data information. It is. Specifically, a communication system in which a plurality of terminal devices to which terminal addresses defined by a protocol are assigned are connected by a communication network, and data in which protocol information is stored is transmitted or received between the terminal devices. Means for determining whether or not to preferentially perform transmission or reception processing as priority determination information in the transmission or reception data, and data to be transmitted or received with priority among the priority determination information Registration means for previously registering priority determination information as priority data information, determination means for extracting priority determination information from the transmission or reception data and determining whether the data is registered as priority data information, and registration as priority data information Data is sent or received with priority over unregistered data. A signal or the reception processing unit, is to a provided.

  That is, the present invention is pre-registered with priority determination information in transmission or reception data in a communication system in which data that requires real-time properties such as multimedia and plant data and data that allows a certain degree of delay are mixed. The order of data transmission or reception processing is determined for each data from the priority data information. As a result, priority control can be performed for each piece of data handled by the communication program of the application without providing communication restrictions.

  In order to achieve the above object, a feature of the present invention is that in a communication system in which a plurality of communication networks are connected, data to be transmitted or received is transmitted to one of the communication networks of the transmission destination or the transmission source. Data transmission identifiers, data division identifiers are assigned, priorities are associated with the data division identifiers, and priority control is performed based on the priority corresponding to the division identifiers of the data when transmitting or receiving the divided data. It is to be. Specifically, a communication system in which a plurality of terminal devices to which terminal addresses defined by a protocol are assigned are connected by a communication network, and data in which protocol information is stored is transmitted or received between the terminal devices. A transmission data dividing unit for dividing the transmission data, a priority determination unit for determining whether the data is priority data or non-priority data from the priority determination information of the protocol header in the divided transmission data when the data is received, and reception data Table storage means for storing a table associating whether or not the data division identifier in the header is prioritized, and determining whether or not the data division identifier has priority when receiving the divided transmission data A table determining unit and a unit for performing priority control of transmission or reception processing according to the determination result in the table determining unit are provided.

  That is, according to the present invention, the priority processing order determined in the data transmission processing is stored in the priority information of the protocol header in the data, and transmission / reception priority control is performed according to the information. Also, when sending divided data, when receiving data, when determining the priority from the priority determination information in the protocol header in the data, having a table associated with the data division identifier of the data, and when receiving the divided data The priority corresponding to the identifier of the data is obtained from the table, and priority control is performed. As a result, priority control can be applied to data that does not have a service identifier in the protocol header in the data, and it can be applied to an inter-network relay device or terminal that connects a plurality of communication networks.

Furthermore, the feature of the present invention for achieving the above object is that the data to be preferentially processed is generated a certain number of times, or is not processed even if a certain time elapses after low priority data is generated. This is to process low priority data to such an extent that it does not affect priority data processing. Specifically, means for registering the upper limit number of times that data to be preferentially processed can be transmitted / received continuously, and data to be preferentially processed after a non-prioritized data transmission / reception processing request is generated Means for integrating the number of times of transmission and reception processing, and means for determining whether or not the number of times integrated by the integration means is equal to or greater than the registered upper limit number in data transmission or reception processing for priority processing When the number is equal to or greater than the upper limit number, transmission or reception processing means is provided preferentially for the number of registered non-priority processing waiting data.
Instead of the upper limit count, an upper limit time that allows data to be transmitted or received to remain in the system may be used, and an upper limit time that data to be transmitted or received can remain in the system is determined for each priority processing level. You may use the upper limit time for each level registered in.

  In other words, the present invention does not affect high-priority data processing if data to be preferentially processed is generated a certain number of times or if it is not processed even after a certain period of time has elapsed since low-priority data was generated. To the extent it processes lower priority data. As a result, even if high-priority data is continuously generated, transmission or reception processing of low-priority data will not be interrupted completely. It can be avoided.

  The characteristics of the present invention described above and the characteristics of the present invention other than those described above will be further clarified by the following description.

  According to the present invention, priority control can be realized without providing communication restrictions for each data handled by an application communication program.

  Further, according to the present invention, priority control can be realized in a communication system including an inter-network relay device.

  Further, according to the present invention, even if processing of high priority data occurs continuously, it is possible to prevent congestion of a communication network and prevention of disconnection of a logical line without causing starvation in low priority data.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
<Overall system configuration>
First, FIG. 2 shows the overall configuration of a communication system targeted by the present invention. A plurality of terminals 200 to 206 are connected to communication networks 211 to 214 such as a standard LAN or WAN, and the respective communication networks 211 to 214 are connected by inter-network relay apparatuses 207 to 210. Each terminal and the inter-network relay device is implemented with a world standard or industry standard communication protocol, and a network address defined by the protocol is assigned. Each terminal is equipped with a communication program, and business processing of the entire system is advanced while data is transmitted and received between the terminals. The data transmission request from the communication program and the data reception from the communication network are transmitted to the communication network and passed to the communication program via the communication protocol installed in the terminal. When data is transmitted from a communication program of a certain terminal to a communication partner terminal, a plurality of communication networks are relayed by the inter-network relay device and reach the communication partner terminal.

  The terminal to which data is delivered is determined by the network address defined by the network layer protocol when it is associated with the OSI reference model. The process to which the data is delivered on the destination terminal is determined by the transport layer when it is associated with the OSI reference model. It is determined by the destination service identifier specified by the protocol.

Hereinafter, in the embodiment, TCP, UDP, DARPA protocol is used as a communication protocol.
A communication system using IP will be described as an example. In the DARPA protocol TCP / IP, a network address is an Internet address, and a service identifier is a port number. When the communication program of each terminal performs data communication with the communication program of other terminals, use either a connection type or datagram type communication method, specify the Internet address and destination port number of the communication partner terminal, and Logically connected to terminals and communication programs. The partner communication program identifies the terminal and communication program to which a response is returned by the source Internet address and the source port number. Normally, in connection-type communication, the source Internet address, destination Internet address, source port number, and destination port number are determined when the connection is established. During datagram type communication, it is determined in data units.
[Example 1]
<Configuration>
The first embodiment will be described below.

The configuration of the priority communication control system of the communication system of the present invention is shown in FIG. Each terminal 140 in the communication system, such as a communication program processing unit 120 that performs business processing in the communication system, a protocol transmission processing unit 141, a protocol reception processing unit 143, a data transmission processing unit 126 to the communication network via the communication device 111, A data reception processing unit (also referred to as data receiving means) 130 from a communication network and processing queue control units 142 and 144 for transmission / reception data are provided. The protocol transmission processing unit 141 includes TCP / IP protocol transmission processing units 121 to 122, and the protocol reception processing unit 143 includes TCP / IP protocol reception processing units 134 to 135. The transmission / reception data processing queue control units 142 and 144 are data priority determination units 123 and 131 for determining whether to process data preferentially, and units 124 and 132 connected to the transmission / reception processing queues 127 and 136. And means 125 and 133 for fetching data from the transmission / reception processing waiting queues 124 and 132. Further, a priority data information registration file 101 for storing priority data information is provided in the auxiliary storage device 100, and a priority data information registration memory 102 and a transmission / reception processing upper limit registration file 103 are arranged on the main memory for preferential transmission / reception. Data priority data information is notified to the data priority determination means 123 and 131.

  The priority data registered in the priority data information registration file 101 is composed of the protocol type of communication protocol information stored in the data, the destination and source port number in the TCP header, the destination and source network address in the IP header. This is the priority determination information used for determining whether or not transmission / reception data is preferentially transmitted / received. The priority data information registration file 101 is set when the communication system is constructed, and is stored and managed in the priority data information registration memory 102 in the main memory when the system is started up. It is not necessary to store the priority data information of the auxiliary storage device 100 in all terminals and inter-network relay devices, the priority data information management server terminal exists in the system, and other terminals and inter-network relay devices are started up. A time communication request may be issued and taken into the priority data information registration memory 102 in the own apparatus. The priority data information may be assigned statically or may be dynamically added, changed, or deleted.

  Compared with the above-described configuration of the terminal, the inter-network relay device usually has a configuration similar to that of the terminal 140 although some devices are not equipped with the communication program processing unit 120 and the TCP protocol transmission / reception processing units 121 and 135. However, the inter-network relay device is connected to two or more communication networks by two or more communication devices, and has a function of transmitting and relaying data received from each communication network to another communication network.

  Input from the outside to the communication system is performed from a predetermined terminal on a communication network (also referred to as a communication network) 110, and includes a communication device 111, data receiving means 130, received data priority determining means 131, and received data connecting means. 132, 136, received data extraction means 133, IP protocol reception processing unit 134, TCP protocol reception processing unit 135, and communication program processing unit 120 are transmitted and processed in this order.

  The output of the processing result to the outside of the communication system includes a communication program processing unit 120, a TCP protocol transmission processing unit 121, an IP protocol transmission processing unit 122, a transmission data priority determination unit 123, a transmission data connection unit 124, and a transmission. Processing is performed in the order of the processing waiting queue 127, transmission data extraction unit 125, data transmission unit 126, and communication device 111, and the data is output to a predetermined terminal on the communication network 110.

The communication program of one of the terminals in the system outputs data, flows through the communication network, and the data is delivered to the receiving-side communication program by the processing procedure at the time of the input of the destination terminal. However, when an inter-network relay device is present, input is performed from a predetermined terminal on the communication network 110, the communication device 111, the data receiving means 130, the received data priority determining means 131, the received data connecting means 132, 136, reception data extraction means 133, IP protocol reception processing section 134, IP protocol transmission processing section 122, transmission data priority determination means 123, transmission data connection means 124, transmission processing wait queue 127, transmission data extraction The data is transmitted in the order of the means 125, the data transmission means 126, and the communication device 111, and is output to a predetermined terminal on the communication network 110.
<Transmission processing>
Processing from the communication program to data transmission to the communication network will be described with reference to FIG. Data transmitted from the communication program processing unit 120 is added with a TCP header by the TCP protocol processing unit 121 of the protocol transmission processing unit 141, and then an IP header is added by the IP protocol transmission processing unit 122. Then, the transmission data priority determination means 123 checks the information in the protocol header in the data to determine whether to perform priority transmission or non-priority transmission. The transmission data connection means 124 is connected to one of the waiting queues. If no data is connected to the transmission processing waiting queue 127 in the transmission data connection unit 124 and if no data transmission request is issued to the communication device 111 in the data transmission unit 126, transmission processing is performed. The data is directly transferred to the data transmission means 126 without connecting the data to the waiting queue 127. The data transmission unit 126 adds a data link layer header (MAC header at the time of transmission to the LAN) to the transmission data, activates the communication device 111 and transmits the data to the communication network 110.

When the data transmission unit 126 issues a data transmission request to the communication device 111 and no data is connected to the transmission processing waiting queue 127 or when the data transmission unit 126 transmits a data transmission request to the communication device 111. , And data is connected to the transmission processing queue 127, the data is connected to the transmission processing queue 127. The data connected to this queue is transmitted next from the transmission processing waiting queue 127 when the processing that the data transmission means 126 currently requests to transmit to the communication device 111 is completed and an end interrupt is received from the communication device 111. The data to be transmitted is extracted by the transmission data extraction means 125 and a transmission request is made to the communication device 111. The number of data extracted by the transmission data extracting unit 125 is the number of data that can be received next by the communication device 111. That is, the communication apparatus 111 stores the data requested from the data transmission unit 126 in the transmission processing queue 127 until the data is transmitted to the communication network 110 and is terminated. Next, when the data transmission unit 126 to the communication network operates, the transmission data extraction unit 125 extracts data in order from the priority data and performs transmission processing.
<Reception processing>
With reference to FIG. 1, a process from receiving data from a communication network to passing it to a communication program will be described. When the communication device 111 receives data from the communication network 110, the communication device 111 reports an interrupt to the data receiving unit 130, and the data receiving unit 130 takes in the data from the communication device 111. The received data priority determination means 131 checks the information in the protocol header in the received data to determine whether to receive priority or non-priority reception, and waits for priority data processing waiting queue or non-priority data processing waiting in the reception processing waiting queue 136. The received data is connected to any one of the queues by the connection means 132. If no data is connected to the reception processing waiting queue 136, the protocol reception processing unit 143 is activated and the reception processing by a series of interrupt reports ends. If data is connected, the reception process is immediately terminated. When the protocol reception processing unit 143 is activated, the reception data extraction unit 133 extracts one high-priority data to be processed next from the reception processing waiting queue 136, passes the data to the IP protocol reception processing unit 134, and If the data is destined for the terminal, the data is passed to the communication program processing unit 120 via the upper TCP protocol reception processing unit 135.

  When the IP protocol reception processing unit 134 determines that the data is not addressed to the terminal itself and should be relayed, the received data is passed to the IP protocol transmission processing unit 122 of the protocol transmission processing unit 141, and the transmission data priority determination unit 123 is transmitted. , Transmission data connection means 124, transmission data extraction means 125, and data transmission means 126.

The protocol reception processing unit 143 repeats the protocol reception processing as long as data is connected to the reception processing waiting queue 136. Even when the protocol reception processing unit 143 is operating, the data receiving means 130 from the communication network performs an interrupt operation. For this reason, data received from the communication device 111 is connected to and accumulated in the reception processing wait queue 136. The stored data is extracted from the collected data by the reception data extraction means 133 to the protocol reception processing unit 143, and the protocol reception processing is performed.
<Priority determination information>
The priority determination information in the protocol header referred to for determining whether the received / transmitted data should be prioritized or non-prioritized data will be described.

  FIG. 3 shows a configuration example of the data frame 300 flowing through the communication network. The data frame 300 is a TCP / IP frame configuration example when IEEE802.3 is used as a data link layer. In addition, there are Ethernet frames and IEEE 802 frames. The priority determination information when the TCP / IP protocol is used includes data protocol type, destination port number 332 in the TCP header 330, source port number 331, destination Internet address 322 in the IP header 320, and source Internet address. (INA) 321.

  As the protocol type, the protocol type 311 in the SNAP header in the physical header 310 including the IEEE 802.3 MAC header, LLC (Logical Link Control), and SNAP (Sub Network Access Point) is used. The protocol type 311 is a DARPA protocol in which a type number and a protocol name are described in Request for Comments (RFC). The IP protocol is 800 and the ARP is 806 in hexadecimal notation. In order to further limit the protocol type, when the protocol type 311 is IP, the protocol 326 (IP upper protocol) in the IP header 312 is used. As the protocol 326, protocols such as TCP, UDP, and ICMP are defined by RFC. As the Internet address, a source INA (Internet address) 321 and a destination INA 322 of the IP header 320 are used. As the port number, the source port number 331 and the destination port number 332 in the TCP or UDP header 330 are used.

In the format shown in FIG. 4, the priority data information registration memory 102 shown in FIG. 1 stores which combination of the priority determination information is preferentially transmitted / received. That is, the protocol type 401 in the data physical header 310, the protocol type 402 in the IP header, the source INA 403, the destination INA 404, the source port number 405, and the destination port number 406 are stored in the corresponding portions. ing. Protocols include protocols that are used directly from the protocol processing in the system such as TCP and UDP protocols and ARP and ICMP that are used for processing of the communication program in the communication program processing unit 120 and are not used directly from the communication program. If all protocols are registered as priority data information, the overhead for searching the priority data information registration memory increases and communication performance is delayed. Therefore, protocols that are not used by direct communication programs such as ARP and ICMP are processed in advance as priority data. May be. Processing such as hashing for speeding up the overhead of searching the priority data information registration memory is also incorporated. In addition, when the value stored in the priority data information registration memory is 0 so that it is not necessary to compare all the information for priority determination, the item is not compared. This value may be 0 or −1, but should be a value that is not used in the priority determination information.
<Priority determination>
FIG. 5 shows a flowchart of an example of transmission / reception data priority determination means. In this example, the protocol type of the data to be transmitted / received in the processes 500 and 505 is checked. If it is ARP or ICMP, it is unconditionally preferred data, and if it is a protocol other than ARP, ICMP, TCP or UDP, it is designated as non-priority data. deal with. If the data is TCP or UDP protocol, the data and all the destinations, source port numbers, and destinations and source Internet addresses in the priority data information registration memory are compared in processes 510 to 550. When the priority data information is 0, the next priority data information is compared without comparison. When it is registered, it is regarded as priority data, and when it is not registered, it is regarded as non-priority data.

Instead of the processing 500 and 505, the comparison processing of the information item protocol type 401 in the priority data information registration memory, the protocol type 311 in the data header, the protocol 326 and the IP upper protocol 402 is put between the processing 510 and 505. You can also. When matching items of the protocol type 311 and protocol 326 in the data header and the information item protocol type 401 and the IP upper protocol 402 in the priority data information registration memory are registered, the process 501 and subsequent determinations are performed. If not registered, it is determined as non-priority data.
<Processing queue configuration>
After the data priority determination as described above, the transmission / reception data connection means is connected to the transmission / reception data processing waiting queue. The configuration of the transmission / reception processing wait queue will be described before explaining the method of connecting and retrieving data from / to the transmission / reception processing wait queue.

  FIG. 6 shows a configuration diagram of a transmission / reception data processing waiting queue. The transmission / reception data processing waiting queue includes a queue header 610 composed of information used for transmission / reception data processing waiting queue control, a priority data processing waiting queue 620, and a non-priority data processing waiting queue 630. The priority data processing waiting level queue 620 and the non-priority data processing waiting level queue 630 have the same structure. In each processing queue, the maximum number of continuously extractable data 621 and 631, which is the number of data that can be continuously extracted for each queue, and the current number of continuously extractable data 622 and 632, and how many processes are currently in each queue. The number of processing waiting data 623, 633 for counting whether waiting data is connected The data header addresses 624, 635 of the data list in the processing waiting state of the FIFO of data connected to the corresponding priority level queue And 625,635. The data internal processing structure 640 connected to each queue includes a data management header 641 for storing data control information such as data attributes and priority information, and a data portion 642.

  An example of the initial information of the waiting queue is shown below when the total number of data 611 in the queue header 610 in FIG.

For the upper limit number of times of transmission or reception, the transmission or reception processing upper limit registration file 103 is arranged in the auxiliary storage device 100, and the upper and lower processing upper limit counts are registered. The upper limit number of times is the continuous extraction upper limit number 621 in the priority data processing waiting queue 620 of the transmission or reception processing waiting queue 600 and the continuous extraction in the non-priority data processing waiting queue 630 before starting the data transmission or reception processing. Stored in the upper limit number 631. 0 is stored in the current number of continuous fetching times 622, 632, the number of other processing waiting data, the head processing waiting data addresses 624, 634, and the final processing waiting data addresses 625, 635. The values of information other than the retrieval upper limit counts 621 and 631 are changed by data connection processing to the processing queue and data retrieval processing.
<Connection method>
FIG. 7 shows a flowchart of a method for connecting data to the transmission / reception processing waiting queue. In step 710, it is determined whether the data to be connected has priority or non-priority. If it is priority data in the process 720, it is connected next to the data indicated by the final process wait data address 625 of the priority data process wait queue, and the process wait data count 623 of the priority data process wait queue is incremented by one. If it is non-priority data, the process 730 connects to the data indicated by the final process wait data address 625 of the non-priority data process wait queue, and adds 1 to the number of process wait data 623 in the non-priority data process wait queue. Finally, in process 740, 1 is added to the total number of data 611 in the queue header.
<Removal method>
Next, FIG. 8 shows a flowchart of a method of extracting data to be transmitted or received from the transmission / reception data processing waiting queue. This process includes a process for preventing the non-priority data from being taken out of the transmission or reception process waiting queue and falling into a starvation state by continuously processing the priority data. The starvation state prevention method shown in this flow is an example using the number of continuous processing of priority data and non-priority data.

  Processing 810 to 825 is data extraction processing from the priority data processing waiting queue. Processing 850 to 860 is data extraction processing from the non-priority data processing waiting queue. Processes 830, 840, 845, 865, and 870 are adjustment processing units for preventing starvation. In order to prevent starvation of non-priority data, the maximum number of consecutive fetches for each queue and the current number of consecutive fetches are used, and the number of consecutive fetches of priority data is counted as the current number of consecutive fetches. (Or equal to the upper limit number), if there is non-priority data, the non-priority data is extracted. The number of non-priority data to be processed at this time is determined by the upper limit number of retrievals of the registered non-priority data processing queue.

  If normal priority data exists, priority data is extracted from the processing queue by processing 810 to 830 even if non-priority data exists, and the processing data count 623 and the continuous extraction count 622 of the priority data processing queue 620 are set. Subtracted. When the number of consecutive retrievals in the priority data processing waiting queue 620 becomes equal to the maximum number of consecutive retrievals (process 815), the priority data retrieval is interrupted and it is checked whether non-priority data exists (process 840). If non-priority data exists, non-priority data is extracted in processes 855 to 860. Thereafter, in process 865, when the number of consecutive retrievals of non-priority data 632 exceeds the maximum number of consecutive retrievals 631 (or is equal to the upper limit number of times 631), the number of sequential retrievals 632 of the waiting queue for non-priority data and priority data. , 622 are set to 0 (process 870).

  This initialization of the number of consecutive fetches (processes 845 and 870) is performed when there is no data in the transmission / reception process waiting queue (processes 810-850-870), but priority data exists but priority data is continuously stored. When the number of times of retrieval becomes the maximum number of continuous retrievals and non-priority data is attempted to be retrieved, but there is no non-priority data (processing 840-845), the number of times of retrieval 622 and 623 are consecutive for both priority data and non-priority data. This is performed when the upper limit number of times of extraction becomes equal (processes 865-870). Initialization of the number of consecutive fetches is performed at a timing when it is no longer necessary to interrupt the fetching of priority data.

  The above is an example using the integrating means for integrating the number of continuous extractions and the integrated value upper limit number determining means for determining whether or not the integrated value has reached the upper limit number.

  In addition, a method may be employed in which the number of consecutive fetches is initialized in advance with the upper limit count, and is subtracted each time data is fetched to determine whether or not the number has reached zero.

  In addition to the above-mentioned starvation state prevention measures by the number of continuous processing of priority data and non-priority data, the following method may be used. The upper limit time that can remain in the system in the auxiliary storage device 100 is registered in the transmission / reception processing upper limit registration file 103, and stored in each processing waiting queue until data transmission or reception. Then, after connecting the data to the transmission / reception processing waiting queue, the waiting time counter in the data header of the data connected to the queue is added at a fixed period, and the data exceeding the remaining upper limit time (or the remaining upper limit time and Equal data) is taken as the semi-priority data and is taken out from the processing queue. At this time, the number of extracted data is adjusted so as to be one semi-priority data with respect to a plurality of priority data so as not to cause delay of the original priority data. Moreover, the taking-out method incorporating both the method based on the number of times and the waiting time after being connected may be used. Detailed examples of these are given in Example 3.

According to the present embodiment, it is possible to determine the data to be preferentially sent and received by using the protocol type, the Internet address in the IP header, and the port number in the TCP or UDP header. There is an effect of preferentially processing data that requires real-time performance. In addition, by using only the port number as the priority determination information, priority processing can be performed for each service type in the communication system, and the processing overhead for priority determination can be reduced.
[Example 2]
Example 2 will be described below.

  In the first embodiment, an example in which a TCP or UDP port number and an IP Internet address are used as priority determination information even when data is received. However, when the transmission data size from TCP or UDP is larger than the maximum transfer byte number of the lower communication network, the transmission data is segmented (divided) and the received data is reassembled (reassembled). The segmented data includes a data frame that does not include a TCP or UDP header. That is, when segmented data is received, it may not be possible to determine whether the data is priority data or non-priority data using only the priority determination information shown in the first embodiment. A method for avoiding this will be described in the second embodiment.

  The segmenting and reassembling processes are defined as IP protocols and are well known. The segmented data of the transmission data is called a fragment in the IP protocol. A schematic diagram of this fragment is shown in FIG. When an IP protocol transmission request is made for data 900, when the data size from IP header 902 to user data 2 904 is larger than the maximum transfer byte number that can be handled by the destination communication network, data 910 and data 920 are displayed. Split. FIG. 9 shows a diagram divided into two. A TCP / UDP header 913 is added to the first data 910, but a TCP / UDP header is not added to the second and subsequent divided data. In the IP protocol, when one piece of data is divided and transmitted, information that can be reassembled on the side receiving the data is stored in IP headers 912 and 922 in each piece of divided data. The information of the data division identifier 327, the flag 324, and the FO 325 in FIG. 3 is information used for reassembly.

  In the first embodiment, the transmission data determining means is placed next to the IP protocol transmission processing unit 122 in FIG. 1, but in the second embodiment, before the IP protocol transmission processing unit 122 performs the data division processing. Put. Based on the priority determination result, an identifier indicating whether or not the data is prioritized is stored in the priority (951 in FIG. 9) of the datagram in the type of service field (950 in FIG. 9) of all the IP headers to be divided. To do. The subsequent priority transmission processing is the same as that of the first embodiment except that it is determined whether the priority data is non-priority data or not by this priority identifier. The priority identifier value of the data to be stored uses the priority identifier registered in association with each other after identifying whether the data is priority data or non-priority data by the priority determination of the transmission data.

  The structure of the data reception process is substantially the same as in the first embodiment. However, the received data priority determination means 131 in FIG. 1 is different from the method shown in the first embodiment. That is, the different part is determined by using the priority 951 of the datagram in the type of service information in the IP header of FIG. 9 to determine whether the data is a priority data or non-priority data after recognizing that the protocol type is an IP protocol. Is about to do. As described in the data transmission process, the priority level 951 associates a priority identifier with priority data and non-priority data in advance, and performs priority determination according to the value of the priority identifier. The processing after the priority determination is the same as that in the first embodiment.

  According to the present embodiment, it is possible to determine which data is preferentially processed even when transmission / reception data is segmented by an inter-network relay device in a communication system in which a plurality of lower-layer communication networks having different numbers of maximum transfer bytes exist. There is an effect that priority control can be performed without restricting communication devices to which the invention can be applied.

In this embodiment, when data is transmitted, the priority of data corresponding to priority data and non-priority data is stored in the priority information 951 of the protocol header in the data, and when receiving data, the priority of the protocol header in the data An example in which priority is given to data reception processing according to the information 951 has been shown. In this method, a priority identifier indicating whether the terminal has priority over the priority information 951 in the protocol header in the data must be set in advance. For this reason, when data is received and relayed from a terminal that does not perform the above-described processing, there may occur a case where the processing does not operate normally or a priority determination cannot be performed in a terminal or an inter-network relay device that complies with the IP protocol. In order to avoid this, the priority information 951 of the protocol header in the data at the time of data transmission is not stored, but is transmitted as in the first embodiment. Then, as shown in FIG. 3, in the IP header of the previously received data
When the identification (data identifier) 327, the fragment offset 325, and the flag 324 are monitored and determined as the head data of the divided data, it is determined from the priority determination information whether the data should be prioritized, and is the priority data Stored for each data division identifier. One bit is assigned to one data division identifier, and it is possible to manage whether or not the data is priority data for each data division identifier. The initial value is off, and when it is determined that the data should be prioritized from the header information of the head data of the divided data, the corresponding data division identifier flag is turned on. If it is determined that the received data is the fragment offset in the IP header and the second and subsequent data divided from the flag, if the flag corresponding to the data division identifier in the IP header is on, the priority data may be off. Is processed as non-priority data. When the last data of the divided data is received, priority determination is performed, and then the flag corresponding to the data division identifier in the IP header is turned off. In this method, data from a terminal that does not employ a process for setting a value indicating whether or not priority information in the protocol header is prioritized can be controlled with respect to data relayed by an inter-network relay device, and specified by the IP protocol. Even in a terminal or an inter-network relay device that supports the priority 951 of the datagram to be processed, priority control can be performed without violating the protocol.
Example 3
Example 3 will be described below. In the first and second embodiments, priority and non-priority two-level priority control are described. In the third embodiment, an example in which priority control is performed at a plurality of priority processing levels of two or more levels will be described.

  The configuration of the priority communication control method in the communication system is substantially the same as the configuration of FIG. 1 described in the first embodiment, but the configurations of the priority data information registration file 101 and the priority data information registration memory 102, the upper limit of transmission or reception processing The configuration of the registration file 102, transmission / reception processing queues 127, 136, and various management information in the processing queues are different. Further, the transmission / reception data priority determination means 123, 131, transmission / reception data connection means 124, 132, and transmission / reception data extraction means 125, 133 perform processing in consideration of the priority processing level. Further, as a means for preventing a low priority level starvation state, in this embodiment, the fixed period residual accumulation means 150 is used. The configuration of the priority determination information, the processing until data transmission from the communication program to the communication network, and the processing until data is received from the communication network and passed to the communication program are the same as in the first embodiment.

  As the priority data information, the configuration of FIG. 10 in which priority levels are added to the configuration of FIG. 4 described in the first embodiment is used. The priority level of the data having the priority determination information registered in the priority data information is set to the priority control of the subsequent transmission / reception processing using the priority processing level 1007 value in the information coincident with the priority determination information of FIG. Do. If the data priority determination information is not registered in the priority data information registration memory 102, the lowest priority processing level is assigned to perform transmission / reception processing.

  FIG. 11 shows the configuration of the transmission / reception processing wait queue when the priority level is 3. The transmission / reception processing waiting queue 1100 includes a queue header 1110 and processing waiting queues 1110, 1120, 1130, 1140 corresponding to the number of priority processing levels used. The queue header 1110 includes a total data number 1111 for storing the total number of data connected to the processing queue for each priority processing level, an interlaced data list 1112, a priority processing level number 1113, and an interlaced data number 1114. . The interlaced data list 1112 is a list that waits for transmission with the highest priority for data that is determined to be in a starved state by the fixed-period residual accumulating unit 150 after data of a low priority level is connected to the processing queue. The number of priority processing levels 1113 is determined and registered in advance as the number of priority processing levels used in the communication system. The configuration information 1121 to 1123 of the waiting queue for each priority processing level and the data structure 1140 connected to the queue are the same as those described in the first embodiment except that the data header has a residual counter 1150. .

The initial value of the queue header information 1110 is input from the priority data information registration file 101 with the total data number 1111 and the interlaced data number 0, and stores a value registered in advance as the priority processing level number. The processing queue data number 1121 in the processing queue for each priority level is 0, and the remaining upper limit value 1123 is input from the transmission / reception processing upper limit registration file 103, and a value registered in advance is set as an initial value. The data list in the processing queue for each of the queue header 1110 and the priority levels 1120, 1130, and 1140 is in a state where no data is connected.
<Priority determination>
The priority determination method of the transmission / reception data used in the priority control with the priority processing level is replaced with the priority determination information in the data, instead of the processing for unconditionally setting the priority data as in processing 555 in FIG. This is a processing method in which the priority processing level 1007 in the information that matches the priority data information registered in the priority data information registration memory is set as the data priority processing level. In the case of a protocol type other than ARP and IP, an IP protocol upper protocol other than ICMP, TCP, and UDP, or data of priority determination information not registered in the priority data information registration memory (processing 500 to 510), processing 560 is performed. Instead, it is treated as data with the lowest priority processing level. These protocols can be registered in the priority data information registration file shown in FIG. 10 to set the priority processing level. After the priority determination of the data, the priority processing level 1151 is stored in the data header 1141 of FIG. 11 and is transferred to the data connection waiting queue processing. Thereafter, the priority processing level 1151 in the data header is referred to in each process until the data is transmitted to the communication network or the received data is passed to the communication program.

Further, the data head has a residual counter 1150 for accumulating the time remaining in the system from the time of data transmission request or data reception. Residual counter 1150 is initialized to 0 when data transmission is requested or data is received.
<Data connection>
The transmission / reception data is connected to the transmission / reception processing waiting queue 1100 by the data connection means, and the connection flow is shown in FIG. In the process 1200, the data is connected to the end of the process waiting queue corresponding to the priority processing level of the data, and 1 is added to the number of data waiting to be processed in this priority level queue. In step 1210, the total number of data in the queue header is incremented by one.
<Retrieving data>
Hereinafter, the priority processing level will be described as a level, the transmission / reception processing waiting queue will be described as a processing waiting queue, and the processing waiting queue for each priority level will be described as a level queue. FIG. 13 shows a flowchart for extracting one piece of data from the queue for processing using the level. In actual processing, the processing flow in FIG. 13 is looped as many times as the number of data to be extracted, and the data is extracted. In order to simplify the description of the extraction process, the process is limited to the process of extracting one piece of data.

In processing 1300, it is determined from the total number of data in the queue header whether data is currently connected to the processing queue. If no data is connected, the process ends as no data. If one or more data is connected, it is checked in step 1305 whether the data is connected to the interlaced data list in the queue header to be connected when the low priority level data is starved. If interlaced data exists, processing 1335 to 1340 removes data from the queue header and subtracts 1 from the total data number 1111 and the interlaced data number 1114. The data is connected to the interlaced data list by the fixed period residual accumulation means. This means will be described later. Usually, processing 1305
Step 1330 is repeated to search for queues with lower levels in order from the queue with the highest priority level, and search for data that can be retrieved. It is determined in processing 1310 whether there is data in the current search target level queue. If there is processing-waiting data, one data is taken out in processing 1315, and in processing 1320, 1 is subtracted from the total number of data in the processing-waiting queue and the current processing target level queue. If there is no data in the target level queue being searched in process 1310, the priority level searched in process 1325 is changed. In step 1330, it is determined whether the search priority level as a result exceeds the lowest level. If not, the next priority level queue search is repeated from step 1305. If the minimum level is exceeded in process 1330, the process ends with no data to be extracted.
<Fixed-period residual integration means>
Next, FIG. 14 shows a processing procedure for the means for accumulating the remaining time of data that is activated at a fixed cycle and connected in the processing queue. This process is started at a constant cycle according to a pre-registered time, and executes the process shown in the flowchart of FIG. In processing 1400, it is determined whether or not there is data other than processing waiting data in the highest priority level queue and interlaced data in the queue header in the processing waiting queue. If there is data other than the highest priority data and interlaced data, the processing 1405 to 1420 is repeated from the priority level queue one level lower than the highest priority level to the lowest level queue, and all the data waiting for processing remain in the data header. The counter 1150 is incremented by one. As a result of addition, when the remaining upper limit 1123 of the level queue of the data is exceeded (or equal), it is determined that the data is starved (processing 1420), and the level queue to which the data is connected in processing 1425 to 1430 Is removed from the queue header jump list 1112 and the processing waiting data number 1121 is decremented by one.

According to the present embodiment, since a plurality of priority processing levels are used, it is possible to prioritize the data that requires real-time processing when further transmitting / receiving the data. In addition, since the fixed period residual integration means is used, even when high priority data is continuously generated, transmission / reception processing of low priority data is not completely interrupted. It has the effect of avoiding congestion and disconnection of logical lines.
Example 4
Hereinafter, Example 4 will be described. In the case of the third embodiment, priority determination information may not be taken into the segmented data described in the second embodiment and priority determination may not be performed. Therefore, in the present embodiment, a communication method using a plurality of priority processing levels incorporating the priority control method for the segmented and reassembled data described in the second embodiment in the case of the third embodiment will be described.

  In the third embodiment, the transmission data determination unit is placed next to the IP protocol transmission processing unit 122 in FIG. 1, but in this embodiment, before the IP protocol transmission processing unit 122 performs the data division processing, Put. Then, the priority processing level obtained by the priority determination means is stored in the priority (951 in FIG. 9) of the datagram in the type of service field (950 in FIG. 9) of all the data to be divided. Subsequent priority transmission processing is the same as in the third embodiment. The priority value may be stored directly as the priority processing level value, or may be stored as a value converted by the priority level and the priority conversion table, and may be unified within the communication system. The structure of the data reception process is substantially the same as in the third embodiment. However, the received data priority determination means 131 in FIG. 1 is different from the method shown in the third embodiment. The difference is that the priority determination after recognizing that the protocol type is the IP protocol is performed using the priority (951 in FIG. 9) of the datagram in the type of service information in the IP header of FIG. . As described in the data transmission process, the priority processing level is associated with the priority in the IP header in advance, and priority determination is performed according to the registered value of the priority 951. The processing after the priority determination is the same as that in the third embodiment.

  According to the present embodiment, since data segmentation is supported, in addition to the effect of the third embodiment, there is an effect that the present invention can be applied to a communication system including a plurality of different communication networks.

  In this embodiment, when data is transmitted, the priority processing level is stored in the priority information of the protocol header in the data, and when receiving data, the data reception processing is prioritized according to the priority information of the protocol header in the data. showed that. In this method, it is necessary for the terminal to set a processing level that prioritizes the priority information of the protocol header in the data in advance. For this reason, there is a problem that the priority processing level cannot be determined when receiving and relaying data from a terminal that does not perform the above processing. In order to avoid this, at the time of data transmission, it transmits without storing the priority information of the protocol header in the data. Then, the data division identifier (Identification), fragment offset, and flag in the IP header of the data received in advance are monitored, and when it is determined that the data is the head data of the divided data, the priority determination information indicates whether the data should be prioritized. When it is priority data, it is stored for each data division identifier. Then, a table that associates the received data division identifier with the priority processing level is managed. The initial value is 0, the priority processing level is determined from the header information of the head data of the divided data, and the data division identifier and the priority processing level are stored. If it is determined from the fragment offset and flag in the IP header of the received data that the data is the second or subsequent data of the divided data, if the data division identifier in the IP header is stored in the table, Send or receive processing to the priority processing level. If it is divided data but the corresponding data division identifier is not stored in the table, it is assumed that the top data has not yet arrived or has been discarded, and pre-registered priority processing Send or receive at the level. Thereafter, when the head data arrives, the division identifier and priority processing level of the data are stored in the above table. When the last data of the divided data is received, priority determination is performed, and then the division identifier and priority processing level of the data are deleted from the table. The above table is managed by methods such as retrieval, registration, and deletion by hashing for high-speed retrieval. According to this method, it is possible to perform priority control based on the priority processing level for data relayed by the relay apparatus between the networks having different configurations.

  As described above, in a communication system in which data that requires real-time properties such as multimedia and plant data and data that allows a certain amount of delay are mixed, the order of data transmission / reception processing can be determined for each data. There is an effect that priority control can be performed without setting communication restrictions for each data handled by the communication program of the application. In addition, the priority processing level can be set for each communication data unit without setting communication restrictions in the application communication program. Furthermore, since priority control can be performed even for data that does not have a service identifier in the protocol header in the data, there is an effect that can be applied to an inter-network relay device that relays a plurality of different types of communication networks. Even when high-priority data occurs continuously, transmission / reception processing of low-priority data will not be interrupted completely, so there is an effect of avoiding communication network congestion and logical line disconnection due to unnecessary retransmission processing. .

The block diagram of the priority communication control system of a communication system. The figure of the whole communication system. The block diagram of a TCP / IP data frame. FIG. 3 is a configuration diagram of a priority data information registration memory according to the first embodiment. FIG. 5 is a diagram illustrating a data priority determination procedure according to the first embodiment. FIG. 3 is a configuration diagram of a process queue for transmission / reception data according to the first embodiment. The figure which shows the procedure which connects the transmission / reception data of Example 1 to a process waiting queue. FIG. 6 is a diagram illustrating a procedure for extracting transmission / reception data from a processing queue according to the first embodiment. FIG. 10 is a diagram illustrating segmentation processing by the IP protocol according to the second embodiment. FIG. 10 is a configuration diagram of a priority data information registration memory according to a third embodiment. FIG. 10 is a configuration diagram of a transmission / reception data processing waiting queue according to a third embodiment. The figure which shows the procedure which connects the transmission / reception data of Example 3 to a process waiting queue. FIG. 10 is a diagram illustrating a procedure for extracting transmission / reception data from a processing queue according to the third embodiment. The figure which shows the procedure of the fixed period residual integration means of Example 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Auxiliary storage device, 101 ... Priority data information registration file, 102 ... Priority data information registration memory, 103 ... Transmission / reception process upper limit registration file, 110 ... Communication network, 111 ... Communication apparatus, 120 ... Communication program processing part, 121 ... TCP protocol transmission processing unit, 122 ... IP protocol transmission processing unit, 123 ... Transmission data priority determination means, 124 ... Transmission data connection means, 125 ... Transmission data extraction means, 126 ... Data transmission means, 127 ... Transmission processing waiting queue, 130 ... data receiving means, 131 ... received data priority determination means,
132 ... Receiving data connection means, 133 ... Receiving data extraction means, 134 ... IP protocol reception processing section, 135 ... TCP protocol reception processing section, 140 ... Central processing unit, main storage device, 141 ... Protocol transmission processing section , 142... Transmission data processing queue control unit, 143... Protocol reception processing unit, 144... Reception data processing queue control unit, 150.

Claims (13)

In a communication system in which a plurality of terminal devices to which a terminal address defined by a protocol is assigned are connected by a communication network, and data in which protocol information is stored between the terminal devices is transmitted or received,
Means for making priority determination information for determining whether to perform transmission or reception processing preferentially as protocol header information in transmission or reception data;
Registration means for pre-registering priority determination information of data to be transmitted or received with priority among the priority determination information as priority data information;
Determining means for extracting priority determination information from the transmission or reception data and determining whether the data is registered as priority data information;
In the case of data registered as priority data information, transmission or reception processing means for transmitting or receiving data preferentially over data not registered,
A communication system characterized by comprising: In claim 1,
A communication system, wherein at least one of a service identifier and a terminal address in the protocol header information and a protocol type in the protocol header information are used as the priority determination information. The claim 1, further comprising:
Means for registering the upper limit number of times that data to be preferentially processed can be transmitted / received continuously;
Accumulating means for accumulating the number of times of continuous transmission / reception processing of data to be preferentially processed after generation of data transmission / reception processing requests for non-priority processing;
Means for determining whether or not the number of times integrated by the integration means is equal to or greater than the registered upper limit number in the transmission or reception processing of data to be preferentially processed;
If the number of times is equal to or greater than the upper limit number of times, non-priority processing waiting data is preferentially transmitted or received for the number of registered data, and means for clearing the number of times of accumulation,
A communication system characterized by comprising: The claim 1, further comprising:
Means for registering, as an initial value, an upper limit number of times that data to be processed with priority can be transmitted / received continuously;
Subtraction means for subtracting from the initial value the number of times of continuous transmission / reception processing of data to be preferentially processed after generation of a request for transmission / reception processing of non-priority processing, and the number of times subtracted by the subtraction means , When 0, means for preferentially transmitting or receiving non-priority processing waiting data for the number of registered data;
A communication system characterized by comprising: The claim 1, further comprising:
An upper limit time registration means for registering an upper limit time during which non-prioritized data can remain in the system;
A remaining time calculating means for periodically calculating the time remaining in the system after a request for transmission / reception processing of data to be non-prioritized is generated;
Upper limit time determination means for determining whether the time calculated by the remaining time calculation means is equal to or greater than the registered upper limit time;
A non-priority processing waiting data is preferentially transmitted or received when the time calculated by the remaining time calculation means is equal to or greater than an upper limit time. In a communication system in which a plurality of terminal devices to which a terminal address defined by a protocol is assigned are connected by a communication network, and data in which protocol information is stored between the terminal devices is transmitted or received,
A communication characterized in that priority of data corresponding to priority data and non-priority data is stored in priority information of a protocol header in the data, and priority is given to data transmission or reception processing according to the priority information. system. In a communication method in which a plurality of terminal devices to which terminal addresses defined by a protocol are assigned are connected by a communication network, and data in which protocol information is stored between the terminal devices is transmitted or received,
A communication method characterized in that the order of data transmission or reception processing is determined for each data from priority determination information in transmission or reception data and pre-registered priority data information. In a communication method in which a plurality of terminal devices to which terminal addresses defined by a protocol are assigned are connected by a communication network, and data in which protocol information is stored between the terminal devices is transmitted or received,
A step of setting priority determination information for determining whether or not to preferentially perform transmission or reception processing as protocol header information in transmission or reception data;
Pre-registering priority determination information of data to be transmitted or received with priority among the priority determination information as priority data information;
In the data transmission process to the communication network and the data reception process from the communication network, the step of taking out the priority determination information from the transmission or reception data and determining whether the data is registered as the priority data information;
In the case of registered data, the communication method includes a step of transmitting or receiving data preferentially over unregistered data. In a communication method in which a plurality of terminal devices to which terminal addresses defined by a protocol are assigned are connected by a communication network, and data in which protocol information is stored between the terminal devices is transmitted or received,
A communication method characterized by setting a priority processing level of data to be transmitted or received in the priority data information, and performing transmission or reception processing according to the priority processing level. In a communication method in which a plurality of terminal devices to which terminal addresses defined by a protocol are assigned are connected by a communication network, and data in which protocol information is stored between the terminal devices is transmitted or received,
A communication method characterized by storing priority processing order determined in data transmission processing in priority information of a protocol header in data and performing transmission / reception priority control according to the information. In a communication method in which a plurality of terminal devices to which terminal addresses defined by a protocol are assigned are connected by a communication network, and data in which protocol information is stored between the terminal devices is transmitted or received,
A communication method characterized in that when data is divided and transmitted or when divided data is received, the division identifier and priority of the data are associated with each other and priority control is performed based on the corresponding priority. In a communication method in which a plurality of terminal devices are connected by a communication network and transmit or receive data using a protocol,
Low priority data that does not affect high-priority data processing if the data to be prioritized occurs continuously for a certain number of times, or if it is not processed after a certain amount of time has elapsed since the occurrence of low-priority data. The communication method characterized by processing. In a communication method in which a plurality of terminal devices are connected by a communication network and transmit or receive data using a protocol,
A step of registering an upper limit number of times that data to be preferentially processed can be transmitted / received continuously;
A step of accumulating the number of times of continuous transmission / reception processing of data to be preferentially processed after a request for transmission / reception processing of non-priority processing is generated;
Determining whether or not the accumulated number is equal to or greater than the registered upper limit number in the transmission or reception process of data to be preferentially processed;
A communication method comprising a step of preferentially transmitting or receiving non-priority processing waiting data for the number of registered data when the upper limit number of times is exceeded.

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