JP2018101878A - Communication method, communication apparatus, and communication program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication method capable of carrying out communication with an optimal frame size, and a communication apparatus and a communication program.SOLUTION: A communication method includes processing including the steps of: transmitting data with plural data sizes from a first unit to a second unit; transmitting information of the data size of the data, which has been successfully received by the second unit from the first unit, to the first unit; and transmitting the data to the second unit from the first unit with a data size which is selected based on the information of the data size received from the second unit.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a communication technique between apparatuses.

  In order to improve the durability of the network in preparation for natural disasters such as earthquakes and typhoons, the network is meshed. Accordingly, the number of devices arranged on the network has increased, and various devices have been arranged on the network.

  FIG. 1 shows an example of a meshed wide area network. In FIG. 1, communication between L (Layer) 2 switches is performed via a network such as a LAN (Local Area Network) or a WAN (Wide Area Network). However, what kind of network is between the L2 switches is not always clear in the case of the wide area network as shown in FIG. When a frame is transferred in such a network (hereinafter referred to as an unknown network), the frame may be discarded. As a cause thereof, there is a device in the unknown network that discards frames of a specific size or more. When a frame is discarded in an unknown network, the L2 switch cannot acquire data (for example, data used for recovery from a failure) from another L2 switch, and a situation may occur in which recovery from the failure is delayed. .

  There are documents that disclose techniques for determining the size of a packet used for communication. However, this technique aims at stabilizing communication quality and reducing the bit error rate, and is not suitable for solving the problem of frames being discarded in an unknown network during communication.

International Publication No. 2008/108379 JP 2003-209577 A

  In one aspect, an object of the present invention is to provide a technique for performing communication with an optimal frame size.

  In the communication method according to the first aspect, the first device transmits data to the second device with a plurality of data sizes, and the second device successfully receives data from the first device. Including a process of transmitting size information to the first device, and the first device transmitting data to the second device at a data size selected based on the data size information received from the second device. .

  In the communication method according to the second aspect, when data is transmitted to another communication device with a plurality of data sizes, and a response to transmission with a specific data size among the plurality of data sizes is received from another communication device, A process for determining a data size when transmitting data to another communication device based on a specific data size is included.

  In one aspect, communication can be performed with an optimal frame size.

FIG. 1 is a diagram illustrating an example of a wide area network. FIG. 2 is a functional block diagram of the L2 switch. FIG. 3 is a diagram for explaining the outline of the present embodiment. FIG. 4 is a diagram illustrating a processing flow of processing executed by the R device. FIG. 5 is a diagram illustrating a processing flow of processing executed by the R device. FIG. 6 is a diagram illustrating a processing flow of processing executed by the S device according to the first embodiment. FIG. 7 is a diagram illustrating an example of data stored in the DL data storage unit. FIG. 8 is a diagram illustrating an example of data stored in the setting parameter storage unit. FIG. 9 is a diagram illustrating a processing flow of processing executed by the S apparatus according to the first embodiment. FIG. 10 is a diagram for explaining the transmission of the size adjustment frame. FIG. 11 is a functional block diagram of the controller. FIG. 12 is a diagram illustrating a processing flow of processing executed by the S device according to the second embodiment. FIG. 13 is a diagram illustrating a processing flow of processing executed by the S device according to the second embodiment. FIG. 14 is a hardware configuration diagram of a computer. FIG. 15 is a hardware configuration diagram of the relay apparatus.

[Embodiment 1]
In the present embodiment, a plurality of L2 switches are arranged in a wide area network as shown in FIG. 1, and communication between the L2 switches is performed. Each L2 switch has setting data and firmware of one or more other L2 switches. For example, when the L2 switch is replaced due to the occurrence of a failure, the replaced L2 switch can resume operation by downloading setting data, firmware, and the like from the other L2 switch. Such downloading is referred to as “adjacent DL (DownLoad)” in the present embodiment. The data including the setting data and the firmware is referred to as “adjacent DL data”.

  FIG. 2 shows a functional block diagram of the L2 switch of the present embodiment. The L2 switch includes a communication unit 101, a DL request unit 103, a size adjustment unit 105, a DL data management unit 107, a communication buffer 111, a DL data storage unit 113, and a setting parameter storage unit 115. In the communication unit 101, the DL request unit 103, the size adjustment unit 105, and the DL data management unit 107, a program for executing the processing of this embodiment is loaded into a memory (specifically, the memory 2601 in FIG. 15). This is realized by being executed by a hardware processor (specifically, a CPU (Central Processing Unit) 2603 in FIG. 15). The communication buffer 111, the DL data storage unit 113, and the setting parameter storage unit 115 are stored in a memory (specifically, the memory 2601 in FIG. 15) or other storage device (for example, an HDD (Hard Disk Drive) 2605 in FIG. 15). Is provided.

  The communication unit 101 transmits a frame in response to requests from the DL request unit 103 and the DL data management unit 107. The communication unit 101 receives a frame from another L2 switch or the like. Note that the communication unit 101 stores a frame before transmission or a received frame in the communication buffer 111.

  The DL request unit 103 transmits a request frame for adjacent DL data to another L2 switch via the communication unit 101. Also, when the DL request unit 103 receives a request frame of adjacent DL data from another L2 switch via the communication unit 101, if the DL request unit 103 can provide adjacent DL data for the other L2 switch, the DL request unit 103 sends a response frame. It transmits with respect to the said other L2 switch via the communication part 101. FIG.

  The size adjustment unit 105 generates a plurality of size adjustment frames according to the setting parameters stored in the setting parameter storage unit 115, and the generated size adjustment frames are subjected to size adjustment via the communication unit 101 according to the setting parameters. Send to request frame source. When the size adjustment unit 105 receives a size adjustment frame from another L2 switch via the communication unit 101, the size adjustment unit 105 generates a response frame including frame size information based on the received size adjustment frame. Is transmitted to the other L2 switch via the communication unit 101.

  The DL data management unit 107 stores adjacent DL data received in the form of a frame from another L2 switch via the communication unit 101 in the DL data storage unit 113. When the reception of the adjacent DL data is completed, the DL data management unit 107 transmits a completion notification frame to the L2 switch that is the transmission source of the adjacent DL data via the communication unit 101. Also, the DL data management unit 107 transmits the adjacent DL data read from the DL data storage unit 113 in a frame having a size determined by the size adjustment unit 105 to another L2 switch that requests the adjacent DL data. .

  The outline of the present embodiment will be described with reference to FIG. Here, a situation is considered in which a failure occurs during operation of the L2 switch 1s, the L2 switch 1s is replaced, and the L2 switch 1s acquires adjacent DL data from the L2 switch 2s in order to resume operation. Hereinafter, the maintenance target L2 switch 1s is referred to as an R device, and the L2 switch 2s that provides adjacent DL data to the R device is referred to as an S device.

  First, the R device transmits a request frame for adjacent DL data to the S device ((1) in FIG. 3). When the S device can provide the adjacent DL data for the R device to the R device, the S device transmits a response frame to the R device ((2) in FIG. 3).

  The R device transmits a size adjustment request frame to the S device that transmitted the response frame ((3) in FIG. 3). The S device transmits size adjustment frames with a plurality of sizes to the R device according to the setting parameters ((4) in FIG. 3).

  Depending on the size, the frame may be discarded in an unknown network between the R device and the S device, but the R device has successfully received at least one size adjustment frame from the S device. Then, the R device transmits a response frame including information on the size of the largest size adjustment frame among the size adjustment frames successfully received to the S device ((5) in FIG. 3). When the S device receives the response frame, the S device determines a frame size when the S device transmits the frame to the R device according to the size information included in the response frame. Then, the S device transmits adjacent DL data to the R device with the determined frame size ((6) in FIG. 3).

  When the R device can receive the adjacent DL data without omission, the R device transmits a completion notification frame to the S device ((7) in FIG. 3).

  The adjacent DL data request frame and its response frame, the size adjustment request frame and its response frame, and the completion notification frame are sufficiently small in size compared to the adjacent DL data frame. Shall be sent without

  Next, processing executed by the R device will be described in more detail with reference to FIGS. 4 and 5.

  First, the DL request unit 103 of the R device transmits a request frame of adjacent DL data from each of the linked ports among the physical ports of the R device via the communication unit 101 (FIG. 4: step S1). Processing of the L2 switch that has received the adjacent DL data request frame will be described later.

  The DL request unit 103 of the R device receives a response frame of adjacent DL data via the communication unit 101 (step S3). However, when there is no L2 switch having adjacent DL data for the R device, the DL request unit 103 of the R device does not receive a response frame.

  The DL request unit 103 of the R device specifies the S device that provides the adjacent DL data for the R device (step S5). For example, when response frames are received from a plurality of L2 switches, one of the plurality of L2 switches is set as the S device. The DL requesting unit 103 notifies the size adjusting unit 105 of information on the identified S device.

  The size adjustment unit 105 of the R device transmits a size adjustment request frame to the S device specified in step S5 via the communication unit 101 (step S7), and waits for reception of the size adjustment frame from the S device. Perform (step S9).

  The size adjustment unit 105 of the R device determines whether a size adjustment frame has been received (step S11). When the size adjustment frame is received (step S11: Yes route), the process proceeds to step S15 in FIG.

  On the other hand, when the size adjustment frame has not been received (step S11: No route), it is determined whether the retry has been performed a predetermined number of times (step S13). If the retry has not been performed a predetermined number of times (step S13: No route), the process returns to step S7 in order to retry. When the retry is performed a predetermined number of times (step S13: Yes route), the processing shifts to FIG.

  The processing after the terminal A will be described. The size adjustment unit 105 of the R device specifies the size adjustment frame of the maximum size among the size adjustment frames received from the S device (FIG. 5: step S15). The size of the size adjustment frame is measured by the R device. By specifying the size adjustment frame of the maximum size in step S15, the number of frames when receiving adjacent DL data can be reduced, so that efficient reception is possible.

  The size adjustment unit 105 of the R device transmits a size adjustment response frame including size information of the size adjustment frame of the maximum size specified in step S15 to the S device via the communication unit 101 (step S17). .

  After that, the DL data management unit 107 of the R device receives the adjacent DL data transmitted by the S device with the frame size determined based on the above maximum size via the communication unit 101, and the received adjacent DL data is DL. The data is stored in the data storage unit 113 (step S19).

  When the DL data management unit 107 of the R device receives the adjacent DL data to be received without omission, the DL data management unit 107 transmits a completion notification frame to the S device via the communication unit 101 (step S21).

  And R apparatus restarts (step S23). Then, the process ends. As a result, the R device operates based on the firmware included in the adjacent DL data, and the setting data included in the adjacent DL data is reflected, so that the operation can be appropriately resumed.

  Next, processing executed by the S apparatus will be described in more detail with reference to FIGS.

  First, the DL request unit 103 of the S device receives a request frame for adjacent DL data from the R device via the communication unit 101 (FIG. 6: step S31).

  The DL request unit 103 of the S device determines whether the adjacent DL data for the R device exists in the DL data storage unit 113 (step S33).

  When there is no adjacent DL data for the R device in the DL data storage unit 113 (step S33: No route), the DL request unit 103 of the S device has the adjacent DL data for the R device in another L2 switch in the network. Determination is made (step S35).

  The S apparatus manages data as shown in FIG. 7 in the DL data storage unit 113. In step S35, the DL request unit 103 makes a determination using the data as shown in FIG. In the example of FIG. 7, data is stored for an ID (IDentifier) of another L2 switch and adjacent DL data for another L2 switch that the L2 switch has. For example, the entry in the first row indicates that the L2 switch 10s has adjacent DL data for the L2 switch 11s and adjacent DL data for the L2 switch 14s. In the present embodiment, each L2 switch manages data as shown in FIG.

  When there is adjacent DL data for the R device in another L2 switch in the network (step S35: Yes route), the process proceeds to step S37. On the other hand, when there is no adjacent DL data for the R device in the other L2 switches in the network (step S35: No route), the processing shifts to FIG.

  On the other hand, when the adjacent DL data for the R device is in the DL data storage unit 113 (step S33: Yes route), the DL request unit 103 of the S device sends a response frame to the request frame of the adjacent DL data to the R device. Then, the data is transmitted via the communication unit 101 (step S37).

  The size adjustment unit 105 of the S apparatus determines whether a size adjustment request frame has been received within a predetermined time after executing the process of step S37, for example (step S39). If the request frame for size adjustment has not been received (step S39: No route), the processing shifts to FIG.

  On the other hand, when the request frame for size adjustment is received (step S39: Yes route), the size adjustment unit 105 of the S apparatus reads the setting parameter for size adjustment from the setting parameter storage unit 115 (step S41). The process proceeds to step S43 in FIG.

  FIG. 8 shows an example of data stored in the setting parameter storage unit 115. In the example of FIG. 8, the setting parameter “StartFrameSize”, the setting parameter “EndFrameSize”, the setting parameter “FrameUnitSize”, the setting parameter “OneShotNumber”, and the setting parameter “OneShotInterval” are stored. The meaning of each setting parameter will be described later.

  Shifting to the description of FIG. 9, the size adjustment unit 105 of the S apparatus transmits a plurality of size adjustment frames having different sizes (here, the number of setting parameters “OneShotNumber”) according to the setting parameters read in step S <b> 41. Is transmitted to the R device via the terminal (FIG. 9: step S43).

  The transmission of the size adjustment frame will be described with reference to FIG. In the present embodiment, size adjustment frames are transmitted in descending size order. In the example of FIG. 10, a size adjustment frame of 10000 bytes is transmitted first, then a size adjustment frame of 9900 bytes is transmitted, and so on. The setting parameter “FrameUnitSize” is a parameter for setting the amount of change in the frame size. The setting parameter “StartFrameSize” is a parameter for setting the frame size of the size adjustment frame transmitted first. When five frames from 10,000 bytes to 9600 bytes are transmitted, the time transmission of the setting parameter “OneShotInterval” is stopped. The setting parameter “OneShotNumber” is the number of size adjustment frames transmitted from the end of transmission stop to the next stop of transmission. When the stop of transmission ends, a size adjustment frame from 9500 bytes to 9100 bytes is transmitted. When the size of the size adjustment frame becomes equal to or smaller than the setting parameter “EndFrameSize”, the transmission ends.

  Returning to the description of FIG. 9, the size adjustment unit 105 of the S apparatus waits for the setting parameter “OneShotInterval” (step S45).

  The size adjustment unit 105 of the S device determines whether a response frame of the size adjustment frame has been received via the communication unit 101 (step S47). The response frame includes size information generated by the R device.

  When the response frame of the size adjustment frame is received via the communication unit 101 (step S47: Yes route), the process proceeds to step S51. On the other hand, when the response frame of the size adjustment frame has not been received via the communication unit 101 (step S47: No route), the size adjustment unit 105 sets the size of the last transmitted size adjustment frame to the setting parameter “EndFrameSize”. It is determined whether the size is equal to or smaller than the indicated size (step S49).

  If the size of the last transmitted size adjustment frame is not less than or equal to the size indicated by the setting parameter “EndFrameSize” (step S49: No route), the process returns to step S43.

  On the other hand, when the size of the last transmitted size adjustment frame is equal to or smaller than the size indicated by the setting parameter “EndFrameSize” (step S49: Yes route), the size adjustment unit 105 determines whether the size adjustment is completed (step S51). . In step S51, a determination is made based on whether a response frame for the size adjustment frame has been received.

  If the size adjustment has not been completed (step S51: No route), the process ends. On the other hand, when the size adjustment is completed (step S51: Yes route), the size adjustment unit 105 notifies the communication unit 101 that the size adjustment is completed. In response to this, the communication unit 101 determines whether the adjacent DL data for the R device is stored in the DL data storage unit 113 (that is, the adjacent DL data for the R device exists in the own device) (step S53). .

  When the adjacent DL data for the R device is stored in the DL data storage unit 113 (step S53: Yes route), the process proceeds to step S56. On the other hand, when the adjacent DL data for the R device is not stored in the DL data storage unit 113 (step S53: No route), the communication unit 101 executes the following processing. Specifically, the communication unit 101 acquires adjacent DL data for the R device from other L2 switches in the network (step S55). Then, the process proceeds to step S56. In step S55, another L2 switch having the adjacent DL data for the R device is specified using the data shown in FIG. 7, and the adjacent DL data for the R device is acquired from the specified L2 switch.

  Based on the size information included in the received response frame, the size adjustment unit 105 of the S device determines a frame size when transmitting a frame to the R device (step S56). For example, the maximum frame size that is not larger than the frame size indicated by the size information and can be transmitted by the S apparatus is employed. The size adjustment unit 105 notifies the DL data management unit 107 of the determined frame size.

  The DL data management unit 107 of the S device reads adjacent DL data for the R device from the DL data storage unit 113, and transmits the read adjacent DL data via the communication unit 101 in a frame of the notified frame size ( Step S57).

  The DL data management unit 107 of the S device receives the completion notification frame from the R device via the communication unit 101 (step S59). Then, the process ends.

  By executing the processing as described above, the S device can transmit the adjacent DL data with the maximum frame size that can be actually received by the R device. That is, it becomes possible to efficiently download adjacent DL data with an optimal frame size.

[Embodiment 2]
In the first embodiment, each L2 switch in the network has adjacent DL data for other L2 switches, but a controller (for example, a physical server) that centrally manages adjacent DL data for each L2 switch. ) May be arranged in the network, and each L2 switch may obtain adjacent DL data from the controller. Therefore, an example in which a controller is introduced into the network will be described below.

  FIG. 11 shows a functional block diagram of the controller 3 in the second embodiment. The controller 3 includes a DL data storage unit 301. The DL data storage unit 301 stores adjacent DL data for each L2 switch in the network.

  The operation when the S device acquires adjacent DL data from the controller 3 will be described with reference to FIGS. 12 and 13. First, the DL request unit 103 of the S device receives a request frame for adjacent DL data from the R device via the communication unit 101 (FIG. 12: step S61).

  The DL request unit 103 of the S device transmits an inquiry to the controller 3 in the network via the communication unit 101 as to whether or not the adjacent DL data for the R device is included (step S63).

  The DL request unit 103 of the S device determines whether there is adjacent DL data for the R device in the controller 3 based on the answer to the inquiry transmitted in step S63 (step S65).

  If there is no adjacent DL data for the R device in the controller 3 (step S65: No route), the process proceeds to FIG. On the other hand, when the controller 3 has adjacent DL data for the R device (step S65: Yes route), the DL request unit 103 of the S device sends a response frame to the request frame of the adjacent DL data to the R device as a communication unit. It transmits via 101 (step S67).

  The size adjustment unit 105 of the S device determines whether a size adjustment request frame has been received within a predetermined time after the execution of the process of step S67, for example (step S69). If the request frame for size adjustment has not been received (step S69: No route), the process proceeds to FIG.

  On the other hand, when the request frame for size adjustment is received (step S69: Yes route), the size adjustment unit 105 of the S apparatus reads the setting parameter for size adjustment from the setting parameter storage unit 115 (step S71). The process proceeds to step S73 in FIG.

  Shifting to the description of FIG. 13, the size adjustment unit 105 of the S apparatus transmits a plurality of size adjustment frames having different sizes (here, the number of setting parameters “OneShotNumber”) according to the setting parameter read in step S <b> 71. Is transmitted to the R device via the terminal (FIG. 13: step S73).

  The size adjustment unit 105 of the S apparatus waits for the setting parameter “OneShotInterval” (step S75).

  The size adjustment unit 105 of the S device determines whether a response frame of the size adjustment frame has been received via the communication unit 101 (step S77). The response frame includes size information generated by the R device.

  When the response frame of the size adjustment frame is received via the communication unit 101 (step S77: Yes route), the process proceeds to step S81. On the other hand, when the response frame of the size adjustment frame has not been received via the communication unit 101 (step S77: No route), the size adjustment unit 105 determines that the size of the size adjustment frame transmitted last is the setting parameter “EndFrameSize”. It is determined whether the size is equal to or smaller than the indicated size (step S79).

  When the size of the last transmitted size adjustment frame is not less than or equal to the size indicated by the setting parameter “EndFrameSize” (step S79: No route), the process returns to step S73.

  On the other hand, when the size of the last transmitted size adjustment frame is equal to or smaller than the size indicated by the setting parameter “EndFrameSize” (step S79: Yes route), the size adjustment unit 105 determines whether the size adjustment is completed (step S81). . In step S81, a determination is made based on whether a response frame for the size adjustment frame has been received.

  If the size adjustment has not been completed (step S81: No route), the process ends. On the other hand, when the size adjustment is completed (step S81: Yes route), the size adjustment unit 105 notifies the communication unit 101 that the size adjustment is completed. In response to this, the communication unit 101 acquires adjacent DL data for the R device from the controller 3 (step S83).

  Based on the size information included in the received response frame, the size adjustment unit 105 of the S device determines a frame size when transmitting a frame to the R device (step S85). For example, the maximum frame size that is not larger than the frame size indicated by the size information and can be transmitted by the S apparatus is employed. The size adjustment unit 105 notifies the DL data management unit 107 of the determined frame size.

  The DL data management unit 107 of the S apparatus transmits the adjacent DL data acquired from the controller 3 in step S83 via the communication unit 101 in the notified frame size (step S87).

  The DL data management unit 107 of the S device receives the completion notification frame from the R device via the communication unit 101 (step S89). Then, the process ends.

  As described above, even when the controller 3 is introduced into the network, the S device can transmit adjacent DL data to the R device with an optimal frame size.

  Although one embodiment of the present invention has been described above, the present invention is not limited to this. For example, the functional block configuration of the L2 switch described above may not match the actual program module configuration.

  Moreover, the data structure demonstrated above is an example, Comprising: It does not necessarily have to be the above structures. Further, in the processing flow, the processing order can be changed if the processing result does not change. Further, it may be executed in parallel.

  The controller 3 described above is a computer device, and as shown in FIG. 14, a memory 2501, a CPU 2503, an HDD 2505, a display control unit 2507 connected to the display device 2509, and a drive device for the removable disk 2511. 2513, an input device 2515, and a communication control unit 2517 for connecting to a network are connected by a bus 2519. An operating system (OS) and an application program for executing the processing in this embodiment are stored in the HDD 2505, and are read from the HDD 2505 to the memory 2501 when executed by the CPU 2503. The CPU 2503 controls the display control unit 2507, the communication control unit 2517, and the drive device 2513 according to the processing content of the application program, and performs a predetermined operation. Further, data in the middle of processing is mainly stored in the memory 2501, but may be stored in the HDD 2505. In the embodiment of the present invention, an application program for performing the above-described processing is stored in a computer-readable removable disk 2511 and distributed, and installed in the HDD 2505 from the drive device 2513. In some cases, the HDD 2505 may be installed via a network such as the Internet and the communication control unit 2517. Such a computer apparatus realizes various functions as described above by organically cooperating hardware such as the CPU 2503 and the memory 2501 described above and programs such as the OS and application programs. .

  Further, the L2 switch (for example, the R device and the S device) described above is a relay device, and for example, as shown in FIG. 15, a display control unit connected to the memory 2601, the CPU 2603, the HDD 2605, and the display device 2609 In some cases, 2607, a drive device 2613 for the removable disk 2611, an input device 2615, and a communication control unit 2617 (2617 a to 2617 c in FIG. 15) for connecting to a network are connected by a bus 2619. In some cases, the display control unit 2607, the display device 2609, the drive device 2613, and the input device 2615 may not be included. The operating system and the application program for executing the processing in this embodiment are stored in the HDD 2605, and are read from the HDD 2605 to the memory 2601 when executed by the CPU 2603. If necessary, the CPU 2603 controls the display control unit 2607, the communication control unit 2617, and the drive device 2613 to perform necessary operations. Note that data input via any one of the communication control units 2617 is output via another communication control unit 2617. The CPU 2603 controls the communication control unit 2617 to appropriately switch the output destination. Further, data in the middle of processing is stored in the memory 2601 and stored in the HDD 2605 if necessary. In an embodiment of the present technology, an application program for performing the above-described processing is stored in a computer-readable removable disk 2611 and distributed, and is installed from the drive device 2613 into the HDD 2605. In some cases, the HDD 2605 may be installed via a network such as the Internet and the communication control unit 2617. Such a computer apparatus realizes various functions as described above by organically cooperating hardware such as the CPU 2603 and the memory 2601 described above with the OS and necessary application programs.

  The embodiment of the present invention described above is summarized as follows.

  In the communication method according to the first aspect of the present embodiment, (A) the first device transmits data to the second device with a plurality of data sizes, and (B) the second device is the first device. The data size information of the data successfully received from the first device is transmitted to the first device, and (C) the data size selected by the first device based on the data size information received from the second device. The processing includes transmitting data to the second device.

  Depending on the data size, data may be discarded on the communication path. However, as described above, communication can be performed with an optimum data size.

  The first device and the second device may be layer 2 network switches, and the data size may be a frame size.

  In the process of transmitting data with a plurality of data sizes, (a1) data may be transmitted to the second device in descending order of the data size. The maximum data size that can be transmitted can be identified early.

  Further, in the process of transmitting data with a plurality of data sizes, (a2) after transmitting a predetermined number of data, it may be repeated to stop transmission for a certain period of time. It becomes possible to create a time to wait for data size information to be transmitted from the second device.

  Further, in the process of transmitting data size information to the first device, (b1) the maximum data size is specified among the data sizes of the data successfully received, and the specified maximum data size information is the first data size. You may transmit to the apparatus of. By maximizing the data size, communication can be performed efficiently.

  In the process of transmitting data to the second device with the data size selected based on the data size information received from the second device, (c1) data to be transmitted from the first device to the second device. If not, the data may be acquired from a device having the data. Since each device does not need to have data, the storage capacity of the device can be saved. In addition, network management by the administrator is facilitated.

  The communication device according to the second aspect of the present embodiment includes (D) a transmission unit (for example, communication unit 101) that transmits data to other communication devices with a plurality of data sizes, and (E) a plurality of data sizes. When a response to transmission with a specific data size is received from another device, a determination unit (for example, size adjustment unit 105) that determines a data size when transmitting data to another device based on the specific data size And have.

  In the communication method according to the third aspect of the present embodiment, (F) data is transmitted to another communication apparatus with a plurality of data sizes, and (G) transmission with a specific data size among the plurality of data sizes is performed. When a response is received from another communication apparatus, the process includes a process for determining a data size when transmitting data to another communication apparatus based on a specific data size.

  A program for causing the processor to perform the processing according to the above method can be created, and the program can be a computer-readable storage medium such as a flexible disk, a CD-ROM, a magneto-optical disk, a semiconductor memory, a hard disk, or the like. It is stored in a storage device. The intermediate processing result is temporarily stored in a storage device such as a main memory.

  The following supplementary notes are further disclosed with respect to the embodiments including the above examples.

(Appendix 1)
The first device transmits data to the second device with a plurality of data sizes;
The second device sends information of the data size of the data successfully received from the first device to the first device;
The first device transmits data to the second device at a data size selected based on the data size information received from the second device;
A communication method that executes processing.

(Appendix 2)
The first device and the second device are layer 2 network switches;
The data size is a frame size;
The communication method according to attachment 1.

(Appendix 3)
In the process of transmitting data with the plurality of data sizes,
Sending data to the second device in descending order of data size;
The communication method according to attachment 1 or 2.

(Appendix 4)
In the process of transmitting data with the plurality of data sizes,
Repeatedly stop sending for a certain time after sending a certain number of data,
The communication method according to any one of appendices 1 to 3.

(Appendix 5)
In the process of transmitting the data size information to the first device,
Specifying the maximum data size among the data sizes of the data successfully received, and transmitting the specified information on the maximum data size to the first device;
The communication method according to any one of appendices 1 to 4.

(Appendix 6)
In a process of transmitting data to the second device with a data size selected based on the data size information received from the second device,
If the first device does not have data to send to the second device, obtain the data from the device having the data;
The communication method according to any one of appendices 1 to 5.

(Appendix 7)
A transmission unit that transmits data to other communication devices with a plurality of data sizes;
When a response to transmission at a specific data size among the plurality of data sizes is received from the other communication device, a data size when transmitting data to the other communication device based on the specific data size A decision part to decide;
A communication device.

(Appendix 8)
On the computer,
Send data to other communication devices with multiple data sizes,
When a response to transmission at a specific data size among the plurality of data sizes is received from the other communication device, a data size when transmitting data to the other communication device based on the specific data size decide,
A communication program that executes processing.

1s, 2s L2 switch 101 Communication unit 103 DL request unit 105 Size adjustment unit 107 DL data management unit 111 Communication buffer 113 DL data storage unit 115 Setting parameter storage unit 3 Controller 301 DL data storage unit

Claims (8)

The first device transmits data to the second device with a plurality of data sizes;
The second device sends information of the data size of the data successfully received from the first device to the first device;
The first device transmits data to the second device at a data size selected based on the data size information received from the second device;
A communication method that executes processing. The first device and the second device are layer 2 network switches;
The data size is a frame size;
The communication method according to claim 1. In the process of transmitting data with the plurality of data sizes,
Sending data to the second device in descending order of data size;
The communication method according to claim 1 or 2. In the process of transmitting data with the plurality of data sizes,
Repeatedly stop sending for a certain time after sending a certain number of data,
The communication method according to any one of claims 1 to 3. In the process of transmitting the data size information to the first device,
Specifying the maximum data size among the data sizes of the data successfully received, and transmitting the specified information on the maximum data size to the first device;
The communication method according to any one of claims 1 to 4. In a process of transmitting data to the second device with a data size selected based on the data size information received from the second device,
If the first device does not have data to send to the second device, obtain the data from the device having the data;
The communication method according to any one of claims 1 to 5. A transmission unit that transmits data to other communication devices with a plurality of data sizes;
When a response to transmission at a specific data size among the plurality of data sizes is received from the other communication device, a data size when transmitting data to the other communication device based on the specific data size A decision part to decide;
A communication device. On the computer,
Send data to other communication devices with multiple data sizes,
When a response to transmission at a specific data size among the plurality of data sizes is received from the other communication device, a data size when transmitting data to the other communication device based on the specific data size decide,
A communication program that executes processing.

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