JP2015126499A - Transmitting device, receiving device, packet transmitting method, and packet receiving method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transmitting device capable of transferring a packet having high priority without delay while suppressing the amount of data transfer, a receiving device, a packet transmitting method, and packet receiving method.SOLUTION: If a high-priority packet becomes transmittable when a low-priority packet is being transmitted, a scheduler 106 supplies a transmission interruption instruction to an identifier generating unit 107 and a data output unit 108. The identifier generating unit 107 generates an identifier for interruption and an identifier for resumption assigned to the low priority packet. When receiving the transmission interruption instruction, the data output unit 108 assigns the identifier for interruption to the data of the low-priority packet and interrupts the transmission of the low-priority packet. After transmitting a high-priority packet without assigning an identifier to the high-priority packet, the data output unit 108 assigns the identifier for resumption to the data of the low-priority packet whose transmission has been interrupted and transmits the packet.

Description

  The present invention relates to a transmission device, a reception device, a packet transmission method, and a packet reception method, and more particularly to a transmission device, a reception device, a packet transmission method, and a packet reception method when transmission priorities of a plurality of types of packets are different.

  In a general packet transfer device (switch device, router device, etc.), the output order of packets at a specific physical port is determined by QoS (Quality of Service) control. That is, a packet having a high priority is preferentially selected and output within the apparatus. Thereby, the delay which generate | occur | produces in a packet transfer apparatus can be suppressed.

  However, even when QoS control is performed, if there is a packet that has been output from the physical port, it is necessary to output the next packet after waiting for the output of the packet to be completed. Here, the packet handled by the packet transfer apparatus is also a huge packet such as a jumbo frame (9600 bytes). When a jumbo frame (9600 bytes) is output from a 1 Gbps (bit per second) port, the time required to complete the output is 80 us. That is, there is a possibility that transmission of a high priority packet is delayed by 80 us.

  In recent years, attention has been paid to a phase synchronization function by packets (IEEE 1588 or the like). When the above-described transmission delay or delay fluctuation (PDV) occurs, network characteristics necessary for phase synchronization may not be obtained. Hereinafter, a technique related to this problem, that is, a prior art for handling packet priority will be described.

  Patent Document 1 discloses an aspect of a packet control device that can reduce the above-described packet delay. When a specific packet is input to the buffer while a general packet is being output from the buffer, the packet control device interrupts the output of the general packet and executes an interrupt process for outputting the specific packet. The device on the receiving side performs error checking on general packets, and discards them if they are incomplete packets. The packet control device retransmits the general packet whose output is interrupted (paragraph 0033). Patent Document 2 also discloses a technique for stopping output of a packet that is being output and switching to output operation of a packet with high priority.

  Patent Document 3 discloses a frame transfer apparatus using an ATM (Asynchronous Transfer Mode) network. The frame transfer device divides the frame into packet units (48 bytes), and assigns attribute information (frame priority) and position information (information indicating the frame number of the divided packet) to the divided packets. Then send. The receiving device reconstructs the frame from the packet using the attribute information and the position information.

JP2013-121144A Japanese Unexamined Patent Publication No. 2011-19166 JP 2006-128859 A

  In the technique of the above-described Patent Document 1, when a specific packet is stored in the buffer during the output of the general packet, the output of the general packet is interrupted and the transmitted general packet is discarded on the receiving device side. That is, incomplete data is transmitted and received between the opposing devices, and the network bandwidth is wasted. The same applies to Patent Document 2.

  In the technique of Patent Document 3, attribute information and position information are always added to a packet obtained by dividing a frame and transmitted. Since attribute information and position information are always given to each packet, the amount of transfer data increases, and there is a risk of squeezing the network bandwidth.

  In other words, the above-described techniques (Patent Documents 1 to 3) have a problem that packets with high priority cannot be transferred without delay while suppressing the data transfer amount.

  The present invention has been made in view of the above-described problems, and can provide a transmission device, a reception device, a packet transmission method, and a packet reception method capable of transferring a high-priority packet without delay while suppressing a data transfer amount. The main purpose is to provide

One aspect of the transmission device of the present invention is:
A data output unit that reads and outputs a packet to be transferred from the storage unit;
A scheduler that outputs a transmission interruption command when the transmission priority of the first packet that has become transmittable is higher than the transmission priority of the second packet that is transmitted by the data output unit;
When the transmission interruption command is output, the data output unit includes a first identifier that is added to the data being output, and an identifier generation unit that generates a second identifier corresponding to the first identifier,
The data output unit stops the output of the second packet after giving the first identifier to the data of the second packet being output when receiving the transmission interruption instruction, and outputs the first packet to the first packet. After outputting without adding an identifier, the second identifier is added to the data before transmission of the second packet and transmitted.

One aspect of the receiving apparatus of the present invention is:
A cutting data holding unit for holding data with an identifier;
A data input unit for determining whether or not the identifier is attached to the received data,
The data input unit includes:
When the identifier is not attached to a series of data, it is determined that the data is a normal packet and transferred to a subsequent processing unit,
When the identifier is attached to a series of data, the data is stored in the cut data holding unit, the data held by the cut data holding unit is reconstructed, a packet is generated, and transferred to the subsequent processing unit To do.

One aspect of the packet transmission method of the present invention is:
A data output step of reading out and outputting the packet to be transferred from the storage unit;
A scheduling step of outputting a transmission interruption command when the transmission priority of the first packet that has become transmittable is higher than the transmission priority of the second packet transmitted by the data output unit;
When the transmission interruption command is output, the data output unit includes a first identifier assigned to the data being output and an identifier generation step of generating a second identifier corresponding to the first identifier,
In the data output step, upon reception of the transmission interruption command, the output of the second packet is stopped after giving the first identifier to the data of the second packet being output and outputting the first packet. After outputting without adding an identifier, the second identifier is added to the data before transmission of the second packet and transmitted.

One aspect of the packet receiving method of the present invention is:
A cutting data holding step for holding data with an identifier;
A data input step of determining whether or not the identifier is attached to the received data,
In the data input step,
When the identifier is not attached to a series of data, it is determined that the data is a normal packet and transferred to a subsequent processing unit,
When the identifier is attached to a series of data, the data is stored in the cut data holding unit, the data held by the cut data holding unit is reconstructed, a packet is generated, and transferred to the subsequent processing unit To do.

  The present invention can provide a transmission device, a reception device, a packet transmission method, and a packet reception method that can transfer a high-priority packet without delay while suppressing the data transfer amount.

1 is a block diagram showing a configuration of a transmission device 100 according to a first exemplary embodiment. FIG. 3 is a diagram illustrating an operation concept of the transmission apparatus 100 according to the first embodiment. FIG. 3 is a diagram illustrating an operation concept of the transmission apparatus 100 according to the first embodiment. FIG. 3 is a diagram illustrating an operation concept of the transmission apparatus 100 according to the first embodiment. 1 is a block diagram showing a configuration of a receiving device 200 according to a first exemplary embodiment. FIG. 3 is a diagram illustrating an operation concept of the receiving apparatus 200 according to the first embodiment. It is a figure which shows an example of the identifier which the identifier production | generation part 107 concerning Embodiment 1 produces | generates. It is a figure which shows an example of the identifier which the identifier production | generation part 107 concerning Embodiment 1 produces | generates. FIG. 3 is a conceptual diagram illustrating an example of data transmitted by the transmission apparatus 100 according to the first embodiment. FIG. 6 is a diagram illustrating an operation concept of a transmission apparatus 100 according to a second embodiment. FIG. 6 is a diagram illustrating an operation concept of the receiving device 200 according to the second embodiment. It is a block diagram which shows the structure of the transmitter 100 concerning this invention.

<Embodiment 1>
Embodiments of the present invention will be described below with reference to the drawings. The first embodiment mainly relates to a network system composed of a transmission device 100 and a reception device 200. FIG. 1 is a block diagram showing a configuration of transmitting apparatus 100 according to the present embodiment. The transmission apparatus 100 includes a physical port 101, a physical port 102, a switch / QoS control unit 103, a high priority queue 104, a low priority queue 105, a scheduler 106, an identifier generation unit 107, a data output unit 108, and a physical port 109. The transmission device 100 may be any device that transmits a packet, for example, a switch device or a router.

  The physical port 101 and the physical port 102 are physical ports to which packets from other devices are input. Packets input to the physical port 101 and the physical port 102 are input to the switch / QoS control unit 103. Note that the number of physical ports to which a packet is input may be any number (for example, three or more).

  The switch / QoS control unit 103 performs QoS (Quality of Service) control of packets input to the physical ports 101 and 102, and determines the priority of each packet. The packet priority determination method may be a generally used method (such as the method described in Patent Document 1 or Patent Document 2). The switch / QoS control unit 103 stores each packet in the high priority queue 104 or the low priority queue 105 according to the determined priority.

  The high priority queue 104 (first queue) is a queue that stores high priority packets (first packets) that are high priority packets. The low priority queue 105 (second queue) is a queue that stores low priority packets (second packets) that are low priority packets. In the present embodiment, for the sake of clarity of explanation, it is assumed that there are only two types of packet priority (priority), low priority and high priority. Level setting may be made. In this case, a queue corresponding to the number of priority levels set is provided in the transmission device 100. An operation example when three or more priority levels are set will be described later in the second embodiment.

  The transmitting apparatus 100 does not necessarily have to have the same number of queues as the priority level setting number. For example, only one packet storage unit may be provided in the transmission apparatus 100, and the packets in the storage unit may be sorted according to the priority of the packet determined by the switch / QoS control unit 103. That is, the transmission unit 100 only needs to have a storage unit for storing packets, and the input / output format of the storage unit (whether it is a queue) or the number of storage units can be arbitrarily changed.

  The scheduler 106 periodically monitors the high priority queue 104 and the low priority queue 105, and determines the output order of packets according to the storage state of each queue. The scheduler 106 notifies the data output unit 108 of the determined output order. When packets are stored in both the high priority queue 104 and the low priority queue 105, the scheduler 106 determines the output order so that the high priority packets stored in the high priority queue 104 are output with priority.

  When the high priority packet is stored in the high priority queue 104 while the low priority packet is being output, the scheduler 106 inputs a transmission interruption command to the identifier generation unit 107 and the data output unit 108. This transmission interruption command is a command for interrupting transmission of a low priority packet and performing transmission of a high priority packet without delay.

  The scheduler 106 transmits a transmission interruption command, and thereafter periodically monitors the high priority queue 104 to determine whether transmission of the high priority packet has ended. When the transmission of the high priority packet is completed (that is, when the high priority queue 104 becomes empty), the scheduler 106 outputs a transmission restart command to the identifier generation unit 107 and the data output unit 108. The transmission restart command is a command for restarting the transmission of the interrupted low priority packet.

  The identifier generation unit 107 generates an identifier (first identifier) to be added to data constituting the low priority packet being output when a transmission interruption command is input. This identifier is information including the device ID of the transmission device 100 and the identification ID of the queue (low priority queue 105 in this example) in which the low priority packet to be granted is stored. A configuration example of the identifier will be described later with reference to FIG.

  The identifier generation unit 107 generates an identifier (second identifier) corresponding to the identifier (first identifier) generated when the transmission interruption command is input when the transmission resume command is input, and the data output unit 108.

  The data output unit 108 reads a packet from each queue according to the control of the scheduler 106 and transmits the read packet to the receiving device 200 via the physical port 109. Further, the data output unit 108 inserts the identifier supplied from the identifier generation unit 107 into the data constituting the low priority packet being output when the transmission interruption command is input, and then outputs the data. Interrupts packet transmission processing. At this time, the data output unit 108 stores the position of the low priority packet (for example, the number of bytes from the beginning). Note that this position information may be written in the low priority queue 105 instead of being stored in the data output unit 108.

  The data output unit 108 transmits the low priority packet with the identifier (first identifier) and then transmits the high priority packet. The data output unit 108 transmits the high priority packet without attaching an identifier.

  The data output unit 108 receives a transmission restart command after transmitting the high priority packet. When a transmission restart command is input, the data output unit 108 reads out and transmits a low priority packet based on the stored position information. At this time, the data output unit 108 sequentially transmits the data constituting the low priority packet with the identifier (second identifier) generated by the identifier generation unit 107.

  The physical port 109 is a physical port that performs data transfer with the receiving apparatus 200. Data of each packet is input to the physical port 109 from the data output unit 108.

  Next, a specific operation of the transmission apparatus 100 according to the present embodiment will be described with reference to FIGS. FIG. 2 is a conceptual diagram illustrating a processing flow when a low priority packet is input to the transmission device 100. The low priority packet is input to the switch / QoS control unit 103 via the physical port 102.

  The switch / QoS control unit 103 determines that the input packet is a low priority packet, and stores the low priority packet in the low priority queue 105. The scheduler 106 detects a situation where a packet is stored only in the low priority queue 105 by periodically monitoring the queue. Then, the scheduler 106 instructs the data output unit 108 to output from the low priority queue 105. Thereafter, the data output unit 108 sequentially reads the data constituting the low priority packet from the top, and outputs the read data from the physical port 109.

  FIG. 3 is a conceptual diagram illustrating an operation when a high priority packet is input to the transmission device 100 during the output state illustrated in FIG. A high priority packet is input to the switch / QoS control unit 103 via the physical port 101.

  The switch / QoS control unit 103 determines that the input packet is a high priority packet, and stores the high priority packet in the high priority queue 104. The scheduler 106 detects a situation in which packets are stored in both the high priority queue 104 and the low priority queue 105 by periodically monitoring the queue. Therefore, the scheduler 106 determines that the high priority packet is stored in the high priority queue 104 during the output of the low priority packet, and inputs a transmission interruption command to the identifier generation unit 107 and the data output unit 108. When a transmission interruption command is input, the identifier generation unit 107 generates an identifier to be added to data constituting the low priority packet being output and supplies the identifier to the data processing unit 108. The data output unit 108 interrupts the transmission process of the low priority packet after inserting the identifier supplied from the identifier generation unit 107 into the output low priority packet and outputting the data.

  FIG. 4 is a conceptual diagram illustrating the operation of the transmission apparatus 100 after the output of the high priority packet is started (after the state of FIG. 3). The data output unit 108 starts transmission of the high priority packet after interruption of the transmission processing of the low priority packet. The data output unit 108 continues the process until transmission of all data constituting the high priority packet is completed. The scheduler 106 detects the end of transmission of the high priority packet by periodically monitoring the queue. Then, the scheduler 106 outputs a transmission resume command to the identifier generation unit 107 and the data output unit 108. When the transmission restart command is input, the identifier generation unit 107 supplies the data output unit 108 with an identifier corresponding to the identifier generated when the transmission interruption command is input. When a transmission restart command is input, the data output unit 108 reads a low priority packet based on the stored position information, and transmits data with an identifier. An example of an identifier provided by the identifier generation unit 107 will be described later with reference to FIG.

  Next, the configuration and operation of the receiving apparatus 200 that receives a packet transmitted by the transmitting apparatus 100 will be described. FIG. 5 is a block diagram illustrating a configuration of the receiving device 200. The receiving apparatus 200 includes a physical port 201, a data input unit 202, a disconnected data storage unit 203, and a switch / QoS control unit 204.

  The physical port 201 is a physical port to which data is input from the transmission device 100 (or another device). The data input unit 202 determines whether or not the above-described identifier is attached to the input data, and sorts and stores the data according to the determination. The data input unit 202 reconstructs a low priority packet based on the identifier from the data stored in the cut data storage unit 203. Details will be described with reference to FIG.

  The cut data storage unit 203 is a data storage unit that temporarily stores data with an identifier. The switch / QoS control unit 204 performs processing for transferring a packet input from the data input unit 202 to another device. Alternatively, the switch / QoS control unit 204 forwards the packet to an appropriate processing unit when processing the input packet in its own device. When transferring a packet to another apparatus, the process of the switch / QoS control unit 204 is substantially the same as the process of the switch / QoS control unit 103 in the transmission apparatus 100.

  Note that the receiving apparatus 200 may also have a transmission function that the transmitting apparatus 100 has. That is, the receiving apparatus 200 may include a processing unit corresponding to the scheduler 106, each queue, and the data output unit 108 described above. Since the processing of these processing units is the same as that of the transmission device 100, description thereof is omitted.

  Next, with reference to FIG. 6, the operation of the receiving apparatus 200 when receiving a packet will be described. The data input unit 202 determines whether or not an identifier is attached to the input data. If there is no identifier between the data indicating the beginning of the packet and the data indicating the end, the data input unit 202 transfers the input data as it is to the switch / QoS control unit 204. That is, the data input unit 202 transfers the high priority packet as it is to the switch / QoS control unit 204.

  On the other hand, when an identifier is detected between the data indicating the beginning of the packet and the data indicating the end, the data input unit 202 stores the input data in the cut data storage unit 203. And the data input part 202 produces | generates the packet which connected several data stored in the cutting | disconnection data storage part 203, and performs a data check. The data check may be a general Ethernet (registered trademark) FCS (Frame Check Sequence) check or the like, and determines whether the reconstructed data has no problem as a packet. If the data check is successful, the data input unit 202 transfers the reconfigured packet to the switch / QoS control unit 204.

  Next, an identifier generation rule and data structure generated by the identifier generation unit 107 will be described with reference to FIGS. The data output by the data output unit 108 is in a format that is output from the beginning of the data by FIFO (First In First Out), and is transmitted to the opposite receiving device 200 by serial connection. Therefore, the transmission order of the divided low priority packets is not reversed (the transmission order is different from the reception order) and the data is not lost in principle. However, theoretically, the transmission order of the divided low priority packets may be reversed (the transmission order and the reception order are different) or the data may be lost. Therefore, the identifier generation unit 107 generates and assigns identifiers that can deal with these problems.

  FIG. 7 is a data example showing a configuration of an identifier (first identifier) given when an interruption occurs. The identifier includes a suspension fixed definition (for example, a fixed value such as 10101), a device identification ID (ID for identifying the transmission device 100), a queue ID (an ID indicating which queue data is in the queue) , And a serial number (a value indicating what number data is in the packet). The configuration of the identifier is merely an example and may include other data. In addition, the data size of each data (queue ID, etc.) in the figure is merely an example, and other data sizes may be used.

  FIG. 8 is a data example showing a configuration of an identifier (second identifier) attached when resuming from interruption. The identifier is the same as the configuration of FIG. 7 except that the suspension fixed definition of the identifier of FIG. 7 has a restart fixed definition (a fixed value different from the suspension fixed definition).

  When a plurality of interruptions and resumptions occur for one packet, both an interruption identifier (FIG. 7) and a resumption identifier (FIG. 8) are attached to one data. With reference to FIG. 9, description will be given of an identifier assigning process in the case where a plurality of interruptions and restarts are performed. FIG. 9 is a conceptual diagram showing transmission data when three transmission interruption instructions are input during transmission of one low priority packet. In the figure, it is assumed that the numerical values described above identifiers (interrupt identifier, resume identifier) are serial numbers.

  In the example of FIG. 9, the identifier generation unit 107 sets serial numbers in order from 0, and sets a specific serial number (255) for data including the final data of the packet. Therefore, in the example of FIG. 9, the serial numbers attached to the resuming identifiers are changed to 0, 1, 2, 255. As a result, the data input unit 202 can grasp that the packet is cut and transmitted, the order of the cut data, and the location of the final data constituting the packet. The data input unit 202 of the receiving apparatus 200 performs a packet restructuring process when receiving data with the serial number (255).

  When the data input unit 202 receives data having a resuming identifier whose serial number is not continuous in a state where the data is held in the cut data storage unit 203, the data input unit 202 discards the data in the cut data storage unit 203. . This is because the order of data may be reversed. Even when data having a queue number or the like different from the disconnection identifier stored in the disconnection data storage unit 203 is received, the data input unit 202 discards the data in the disconnection data storage unit 203. Similarly, the data input unit 202 discards data even when data having a disconnection identifier whose serial number is other than 0 is received when there is no data in the cut data storage unit 203.

  That is, the data input unit 202 refers to the serial number of the identifier, and when it is considered that the order of the disconnected data is reversed or the data is lost, the packet is accurately reconstructed by discarding the data or the like. The process may be performed as follows. Further, the data input unit 202 may make a data retransmission request or the like together with discarding the data.

  Note that the identifier serial number assignment rule shown in FIG. 9 is merely an example, and is not limited thereto. As described above, inversion and the like of data occur theoretically but hardly occur in reality. Therefore, the rules for generating identifiers may be different from those described above or may be simplified.

  For example, the serial number does not have to be an incrementing rule, and all data other than the serial number assigned to the final data may be the same data. For example, the serial number assigned to the restart identifier may be 0, 0, 0, 255. Since the data output unit 108 transmits the data in order from the beginning of the packet data, even with this method, the reconstruction of the packet can be realized with a certain degree of accuracy. However, when the transmission order and the reception order change due to the network environment or the like, the packet cannot be accurately reconstructed. Therefore, as shown in FIG. 9, the serial number is changed (incremented or decremented) according to a predetermined rule, and a specific serial number is given to the final data of the packet, thereby realizing a more accurate packet reconstruction. be able to.

  Next, effects of the transmission device 100 and the reception device 200 according to the present embodiment will be described. As described above, when the high-priority packet (first packet) can be transmitted during transmission of the low-priority packet (second packet), the transmission device 100 assigns an identifier (first identifier) to data constituting the low-priority packet. ) And then stop sending. Then, the transmission device 100 transmits all data without attaching an identifier to the high priority packet. Thereafter, the transmission device 100 transmits an identifier (second identifier) attached to the remaining data of the low priority packet.

  As described above, the transmitting apparatus 100 does not attach an identifier to a high priority packet, and attaches an identifier only to a low priority packet necessary for packet reconstruction. As a result, identifiers transmitted on the network are minimized, and an increase in traffic volume can be minimized. Also, by attaching an identifier to each piece of data constituting the low priority packet and transmitting it, the receiving apparatus 200 can reconstruct the packet. Furthermore, even when a low priority packet is being transmitted, the high priority packet is preferentially transmitted, so that a high priority packet can be transmitted without delay.

<Embodiment 2>
The present embodiment is characterized in that processing is performed when the packet priority level classification is 3 or more. The differences between the transmitting apparatus 100 and the receiving apparatus 200 according to the present embodiment from the first embodiment will be described below.

  FIG. 10 is a block diagram showing a configuration of transmitting apparatus 100 according to the present embodiment. The transmission apparatus 100 newly includes a medium priority queue 110 in addition to the configuration of FIG. Note that the configuration in FIG. 10 is an example of a configuration in which the priority level division is 3 or more, and the transmission apparatus 100 may have four or more queues (the level division may be 4 or more). . In the following description, it is assumed that there are three queues (high priority queue 104, low priority queue 105, and medium priority queue 110) for clarity of explanation. A packet stored in the medium priority queue 110 is referred to as a medium priority packet (third packet). The medium priority packet is a packet having a lower transmission priority than the high priority packet and a higher transmission priority than the low priority packet.

  An outline of processing of the data output unit 108 will be described. The data output unit 108 transmits packets in the priority order of a high priority packet, a medium priority packet, and a low priority packet during normal operation. However, if the medium priority packet becomes transmittable (stored in the medium priority queue 110) while transmitting the high priority packet after the transmission of the low priority packet is interrupted, the data output unit 108 transmits the low priority packet. Sends a medium priority packet after completion.

  This will be described again with reference to FIG. First, it is assumed that only low priority packets are in the low priority queue 105, and no packets are stored in other queues. In this case, the data output unit 108 sequentially reads data from the top of the low priority packet and performs transmission processing.

  Assume that a high priority packet is input to the high priority queue 104 during transmission of the low priority packet. The scheduler 106 outputs a transmission interruption command to the data output unit 108. In response to the transmission interruption command, the data output unit 108 suspends transmission of the low priority packet after attaching the identifier to the data of the low priority packet. Then, the data output unit 108 starts transmitting a high priority packet.

  Here, it is assumed that the medium priority packet is input to the medium priority queue 110 during transmission of the high priority packet. The scheduler 106 detects an input to the middle priority queue 110. The scheduler 106 detects the end of transmission of the high priority packet. When the transmission of the high-priority packet is completed, the scheduler 106 outputs a low-priority packet transmission restart command to the identifier generation unit 107 and the data output unit 108 instead of transmitting the medium-priority packet.

  In response to this, the data output unit 108 transmits the remaining data of the low priority packet. Thereafter, the data output unit 108 reads out the medium priority packet from the medium priority queue 110 and performs transmission without adding an identifier.

  Next, the operation of the receiving apparatus 200 corresponding to FIG. 10 will be described with reference to FIG. The operation of receiving apparatus 200 is basically the same as that shown in FIG. The data input unit 202 determines whether or not an identifier is attached to the transmitted data. The data input unit 202 supplies data without an identifier to the switch / QoS control unit 204 as it is. Therefore, the high priority packet is directly supplied from the data input unit 202 to the switch / QoS control unit 204. Similarly, since no identifier is attached to the medium priority packet, the medium priority packet is directly supplied from the data input unit 202 to the switch / QoS control unit 204.

  The data input unit 202 stores the data with the identifier in the cut data storage unit 203. The data input unit 202 reconstructs the packet by the same method as in the first embodiment, and supplies the reconstructed packet to the switch / QoS control unit 204. In the example of FIG. 11, since the identifier is attached to the data of the low priority packet, the data input unit 202 supplies the reconstructed low priority packet to the switch / QoS control unit 204.

  Then, the effect of the transmission apparatus 100 concerning this Embodiment is demonstrated. Generally, when there are a plurality of queues and a plurality of types of packets are disconnected, the packet reconstruction process in the receiving apparatus 200 becomes complicated.

  However, when there is a packet for which transmission is interrupted, the transmission apparatus 100 according to the present embodiment performs the above-described control so that a plurality of priority level packets are not divided and transmitted. Therefore, the receiving apparatus 200 can easily perform a packet restructuring operation. Further, by controlling so that a plurality of priority level packets are not divided and transmitted, it is possible to reduce the number of times the identifier is attached and avoid an increase in the traffic amount in the entire network.

<Other embodiments>
As described above, the low priority packet may be divided into a plurality of data and transmitted. Here, when the number of divisions increases, an identifier is assigned to each piece of divided data. Therefore, the amount of data transmitted on the network may increase as the number of wins increases. Therefore, a difference from the first embodiment regarding a method for dealing with an increase in traffic volume will be described below.

  Hereinafter, a first modification will be described. Even when a transmission interruption command is input from the scheduler 106, the data output unit 108 does not immediately interrupt the transmission of the low priority packet, but outputs the low priority packet until output of a fixed byte is completed. continue. Here, the minimum size of the fixed bytes may be 64 bytes, for example. This is because the 64-byte long delay fluctuation hardly causes a problem in the processing on the network.

In the description of FIGS. 7 to 9, the serial number indicating the final data is 255. This is because the following expression is established in relation to this fixed length (64 bytes).
64 bytes x 256 = 16384 bytes> 9600 bytes (maximum size of general jumbo frame)

  Thus, the transmission of the low priority packet is not interrupted immediately, but the number of divisions of the low priority packet can be reduced by not interrupting until the fixed-length data output is completed. By reducing the number of low priority packet divisions, the number of identifiers to be assigned is reduced, and the amount of traffic on the network can be reduced.

  Next, a second modification will be described. As described above, the scheduler 106 periodically checks the storage state of the queue. Therefore, the scheduler 106 stores the input state of the packet at each inspection time. The scheduler 106 calculates the input status of high-priority packets from a test time to a certain time before (for example, X seconds before the test time). Then, the scheduler 106 outputs a transmission resumption command according to whether the input state of the above-described high priority packet is equal to or less than a predetermined threshold together with the queue state.

  Specifically, even if the scheduler 106 is in a state where a packet is stored only in the low priority queue 105 (a state in which no packet is stored in the high priority queue 104), the scheduler 106 performs a high period from the time of this inspection to a certain time before. If the input status of the priority packet is high, the transmission restart command is not output. That is, the scheduler 106 does not output a transmission restart command until transmission of high priority packets is settled. Thereby, it is avoided that the transmission of the low priority packet is resumed in a state where the transmission of the high priority packet is frequently performed. Thereby, the division | segmentation number of a low priority packet reduces and the traffic amount on a network can be reduced.

  The above-described embodiments are merely examples relating to application of technical ideas obtained by the present inventors. That is, the technical idea is not limited to the above-described embodiment, and various changes can be made.

  The processes of the scheduler 106, the identifier generation unit 107, and the data output unit 108 may be realized by a CPU (Central Processing Unit) executing a computer program.

  The computer program can be stored using various types of non-transitory computer readable media and provided to a computer. Non-transitory computer readable media include various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic recording media (for example, flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (for example, magneto-optical disks), CD-ROMs (Read Only Memory), CD-Rs, CD-R / W and semiconductor memory (for example, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (random access memory)) are included. The program may also be supplied to the computer by various types of transitory computer readable media. Examples of transitory computer readable media include electrical signals, optical signals, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.

  Finally, the operation of the transmission apparatus 100 according to the present invention will be described again with reference to FIG. FIG. 12 is a block diagram illustrating a processing unit that performs a characteristic operation of the transmission apparatus 100 according to the present invention.

  The data output unit 108 reads out from the queue (high priority user 104, low priority queue 105) according to the scheduler 106, and transmits it to the receiving device 200. The scheduler 106 monitors the queue and notifies the data output unit 108 of the transmission order. When the high-priority packet can be transmitted during transmission of the low-priority packet (when the high-priority packet is stored in the high-priority queue 104), the scheduler 106 sends a transmission interruption command to the identifier generation unit 107 and the data output unit 108. To supply.

  The identifier generation unit 107 to which the transmission interruption instruction is input generates an interruption identifier (first identifier) and a resume identifier (second identifier) to be given to the low priority packet.

  When the data output unit 108 receives the transmission interruption command, the data output unit 108 suspends the transmission of the low priority packet by adding an interruption identifier to the data of the low priority packet being output. Then, the data output unit 108 starts transmitting a high priority packet. Transmission is performed without attaching an identifier to the high priority packet. After the transmission of the high-priority packet is completed, the data output unit 108 transmits the low-priority packet data whose transmission has been interrupted with a resume identifier.

  With this configuration, high priority packets can be transmitted without delay. Further, since the identifier is transmitted only when transmission of a low priority packet is interrupted and resumed, an increase in the amount of data transmitted on the network can be minimized.

100 transmitting device 101 physical port 102 physical port 103 switch / QoS control unit 104 high priority queue 105 low priority queue 106 scheduler 107 identifier generating unit 108 data output unit 109 physical port 110 medium priority packet 200 receiving device 201 physical port 202 data input unit 203 Disconnection data storage unit 204 Switch / QoS control unit

Claims (12)

A data output unit that reads and outputs a packet to be transferred from the storage unit;
A scheduler that outputs a transmission interruption command when the transmission priority of the first packet that has become transmittable is higher than the transmission priority of the second packet that is transmitted by the data output unit;
When the transmission interruption command is output, the data output unit includes a first identifier that is added to the data being output, and an identifier generation unit that generates a second identifier corresponding to the first identifier,
The data output unit stops the output of the second packet after giving the first identifier to the data of the second packet being output when receiving the transmission interruption instruction, and outputs the first packet to the first packet. A transmission device that outputs the data without adding an identifier, and then transmits the data before the transmission of the second packet with the second identifier. The first identifier and the second identifier include a serial number indicating the number of data from the beginning of the second packet.
The transmission apparatus according to claim 1, wherein: The second identifier includes information indicating whether or not the data constitutes final data of the second packet.
The transmitter according to claim 1 or 2, wherein The data output unit stops outputting the second packet after outputting the data of a predetermined size constituting the second packet after receiving the transmission interruption command;
The transmission apparatus according to any one of claims 1 to 3, wherein The scheduler calculates the input frequency of the first packet. If the input frequency is equal to or higher than a predetermined threshold, the scheduler does not output a transmission resume command for the second packet even after the output of the first packet is completed. ,
The transmitter according to any one of claims 1 to 4, wherein: When the output of the second packet is stopped, the data output unit can transmit a third packet having a higher transmission priority than the second packet and a lower transmission priority than the first packet. Transmitting the third packet after transmission of two packets is completed;
The transmitter according to any one of claims 1 to 5, wherein: A first queue storing the first packet;
A second queue for storing the second packet;
The transmitting apparatus according to claim 1, wherein the transmitting apparatus is configured as described above. A cutting data holding unit for holding data with an identifier;
A data input unit for determining whether or not the identifier is attached to the received data,
The data input unit includes:
When the identifier is not attached to the received data, it is determined that the data is a normal packet and transferred to the subsequent processing unit.
If the identifier is attached to the received data, the data is stored in the cut data holding unit, the data held by the cut data holding unit is reconstructed to generate a packet, and the packet is transferred to the subsequent processing unit , Receiving device. The data input unit determines whether there is no abnormality in the reconstructed packet by FCS check,
The receiving device according to claim 8. The data input unit analyzes the identifier and discards the data stored in the cut data holding unit when a reversal of data transmission order or data loss is detected,
The receiving device according to claim 8 or 9, wherein A data output step of reading out and outputting the packet to be transferred from the storage unit;
A scheduling step of outputting a transmission interruption command when the transmission priority of the first packet that has become transmittable is higher than the transmission priority of the second packet transmitted by the data output unit;
When the transmission interruption command is output, the data output unit includes a first identifier assigned to the data being output and an identifier generation step of generating a second identifier corresponding to the first identifier,
In the data output step, upon reception of the transmission interruption command, the output of the second packet is stopped after giving the first identifier to the data of the second packet being output and outputting the first packet. After outputting without adding an identifier, the second packet is transmitted with the second identifier added to the data before transmission of the second packet.
Packet transmission method. A cutting data holding step for holding data with an identifier;
A data input step of determining whether or not the identifier is attached to the received data,
In the data input step,
When the identifier is not attached to the received data, it is determined that the data is a normal packet and transferred to the subsequent processing unit.
If the identifier is attached to the received data, the data is stored in the cut data holding unit, the data held by the cut data holding unit is reconstructed to generate a packet, and the packet is transferred to the subsequent processing unit ,
Packet reception method.

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