Communication control device, communication control method, program, and communication system

Abstract

To provide a communication control device, a communication control method, a program, and a communication system that enable communication without retransmission when a frame can be restored even in the case that a frame loss occurs in a storage area network using a fiber channel.SOLUTION: A first terminal device 11 generates a first parity frame for each first group on the basis of data of a first data frame included in a first group, adds the first parity frame to the first group, and transmits a plurality of the frames to a second terminal device 12, and the second terminal device 12 receives the plurality of frames from the first terminal device 11, restores the frame-lost second data frame on the basis of the second parity frame when the frame loss of the second data frame is detected, deletes the second parity frame from a second group, and use the second data frame to generate transmission source data.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a communication control device, a communication control method, and a program used in a network, and further to a communication system.

Background Art

[0002] In the connection form of FC (Fiber Channel)-SAN (Storage Area Network) (storage area network using fiber channel), for example, there is a fabric connection using a fiber channel switch (FC-SW), a host bus adapter (HBA), an optical fiber cable, and the like.

[0003] Fiber channel has a hierarchical protocol and is composed of FC0 (physical layer), FC1 (encoding / decoding layer), FC2 (signaling layer), FC3 (service layer), and FC4 (mapping layer). Among them, in FC2, the assembly of frames, which are the minimum units of data, and the control of data transfer are defined.

[0004] The control of data transfer is defined by a service class. A service class is a mechanism for controlling data transfer. There are multiple classes in a service class. In FC-SAN, classes 2 and 3 are often used.

[0005] The difference between class 2 and class 3 is that class 2 makes a data transfer confirmation request in frame units, while class 3 does not make a data transfer confirmation request. Therefore, class 3 has a reduced communication volume and communication load compared to class 2.

[0006] The reason why a data transfer confirmation request is not necessary in class 3 is that since a very low bit error rate is defined in FC1, a strict data transfer confirmation request is not required in FC2.

[0007] However, in the case of a Class 3 fiber channel, when a frame loss occurs, it is necessary to wait for a timeout until the frame is retransmitted in exchange units by the protocol of the upper layer. Therefore, it takes time from the occurrence of the frame loss until it is retransmitted.

[0008] As a related technology, Patent Document 1 discloses a technique for shortening the time from the occurrence of a frame loss to retransmission in a communication control system using Class 3.

[0009] According to the communication control system of Patent Document 1, first, the server transmits frames to the FC-SW in exchange units. Next, when the FC-SW detects a CRC (Cyclic Redundancy Check) error in the received frame, it transmits the header of the frame to the retransmission control device.

[0010] Next, the retransmission control device generates an error notification indicating the occurrence of a frame loss based on the header of the received frame, and transmits the generated error notification to the server. Then, the server retransmits the frame in exchange units based on the received error notification.

Prior Art Documents

Patent Documents

[0011]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0012] However, in the communication control system of Patent Document 1, when a frame loss occurs, the frame is retransmitted in exchange units using a retransmission control device. Therefore, processing time is required for retransmission. Also, in order to perform retransmission, a retransmission control device must be connected to the FC-SAN as new hardware.

[0013] As one aspect, in a storage area network using a fiber channel, when frames can be restored even if frame loss occurs and communication can be performed without retransmission, a communication control device, a communication control method, a program, and a communication system are provided.

Means for Solving the Problem

[0014] To achieve the above object, a communication control device in one aspect is In a storage area network using a fiber channel, when transmitting a plurality of frames to a receiving-side terminal device via a fiber channel switch, a group generation unit that collects a preset number of the frames to generate a first group; A parity frame generation unit that generates a first parity frame for each of the first groups based on the data of the first data frames included in the first group; A parity frame addition unit that adds the first parity frame to a preset position of the first group; It is characterized by having the above.

[0015] Also, to achieve the above object, a communication control method in one aspect is In a storage area network using a fiber channel, when transmitting a plurality of first data frames to a receiving-side terminal device via a fiber channel switch, a group generation step of collecting a preset number of the first data frames to generate a first group; A parity frame generation step of generating a first parity frame for each of the first groups based on the data of the first data frames included in the first group; A parity frame addition step of adding the first parity frame to a preset position of the first group; It is characterized by having the above.

[0016] Also, to achieve the above object, a program in one aspect causes a computer to in a storage area network using a fiber channel, when transmitting a plurality of first data frames to a receiving terminal device via a fiber channel switch, generate a first group by collecting a preset number of the first data frames; a group generation step; generate a first parity frame for each first group based on the data of the first data frames included in the first group; a parity frame generation step; add the first parity frame to a preset position of the first group; a parity frame addition step; and execute the steps, which is characterized in that.

[0017] Furthermore, to achieve the above object, a communication system in one aspect is a communication system of a storage area network using a fiber channel, wherein a first terminal device when transmitting a plurality of first data frames to a second terminal device via a fiber channel switch, generates a first group by collecting a preset number of the first data frames, generates a first parity frame for each first group based on the data of the first data frames included in the first group, adds the first parity frame to a preset position of the first group and transmits a plurality of frames to the second terminal device via the fiber channel switch, wherein the second terminal device when receiving a plurality of frames from the first terminal device via the fiber channel switch, detects whether there is a frame loss for each second group, When detecting a frame loss of a second data frame included in the second group, based on the second parity frame included in the second group, restore the second data frame with the frame loss. After the second data frame with the frame loss is restored, delete the second parity frame from the second group. After the second parity frame is deleted from the second group, generate transmission source data using the second data frame of the second group. It is characterized by the above.

Effect of the Invention

[0018] As one aspect, in a storage area network using a fiber channel, even if a frame loss occurs and the frame can be restored, communication can be performed without retransmission.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiment for Carrying Out the Invention

[0020] Hereinafter, embodiments will be described with reference to the drawings. In the drawings described below, elements having the same function or corresponding functions are denoted by the same reference numerals, and repeated descriptions thereof may be omitted.

[0021] (Embodiment) Using FIG. 1, the configuration of a communication system used in a network such as FC-SAN in the present embodiment will be described. FIG. 1 is a diagram for explaining an example of an FC communication system.

[0022] [System Configuration] The class 3 FC communication system 10 shown in FIG. 1 is a system that can communicate without retransmission when frames can be restored even if frame loss occurs. In the example of FIG. 1, the FC communication system 10 includes a terminal device 11 (first terminal device), a terminal device 12 (second terminal device), and an FC-SW 13. The dashed arrows in FIG. 1 indicate the flow of frames.

[0023] The terminal devices 11 and 12 include a communication control device 20. The terminal devices 11 and 12 are, for example, information processing devices such as server computers and storage devices such as storage. In the present embodiment, the terminal device 11 is described as a server computer and the terminal device 12 is described as a storage. The terminal devices 11 and 12 also have a communication function (not shown).

[0024] The FC-SW 13 is a relay device used to construct the FC communication system 10. In the example of FIG. 1, the FC-SW 13 is provided between the terminal device 11 and the terminal device 12.

[0025] Using FIG. 2, the configuration of the communication control device in the present embodiment will be described. FIG. 2 is a diagram for explaining an example of the communication control device.

[0026] The communication control device 20 is a device including a transmission control unit 21 and a reception control unit 22. The communication control device 20 has, for example, a programmable device such as a CPU (Central Processing Unit), or an FPGA (Field-Programmable Gate Array), or a GPU (Graphics Processing Unit), or a circuit equipped with any one or more of them.

[0027] The transmission control unit 21 has a group generation unit 31, a parity frame generation unit 32, and a parity frame addition unit 33. The reception control unit 22 has a frame loss detection unit 41, a frame restoration unit 42, a parity frame deletion unit 43, and a transmission source data generation unit 44.

[0028] The operation at the time of frame loss will be described with reference to FIG. 3. FIG. 3 is a diagram for explaining the operation of the FC communication system at the time of data frame loss.

[0029] The transmission control unit 21 will be described. When the group generation unit 31 in the FC-SAN (Fibre Channel Storage Area Network) transmits a plurality of data frames (first data frames) to a terminal device (the terminal device on the reception side) via the FC-SW, the group generation unit 31 collects a preset number of data frames to generate a group (first group).

[0030] Specifically, the group generation unit 31 of the transmission control unit 21 of the terminal device 11 executes the process T1 shown in FIG. 3. In the process T1, first, the group generation unit 31 acquires data D (transmission source data) from an upper layer such as SCSI (Small Computer System Interface). Next, the group generation unit 31 divides the data D into data of a preset size.

[0031] Next, the group generation unit 31 generates a plurality of data frames DF using the divided data. Then, the group generation unit 31 collects a preset number of data frames DF to generate groups Gr1, Gr2, ···. Note that the data frame DF does not include frames such as commands and statuses.

[0032] The parity frame generation unit 32 generates a parity frame (first parity frame) for each group based on the data included in the group. Then, the parity frame addition unit 33 adds the generated parity frame to a preset position of the group (first group).

[0033] Specifically, the parity frame generation unit 32 of the transmission control unit 21 of the terminal device 11 executes the process T2 shown in FIG. 3. In the process T2, first, the parity frame generation unit 32 generates a parity frame PF for each of the groups Gr1, Gr2, ··· based on the divided data included in the group.

[0034] Next, the parity frame addition unit 33 of the transmission control unit 21 of the terminal device 11 adds the parity frame PF generated for each of the groups Gr1, Gr2, ··· by the parity frame generation unit 32 to a preset position of the corresponding group.

[0035] Note that the headers of the data frame DF and the parity frame PF include sequence numbers.

[0036] When the above-described processes T1 and T2 are completed, the terminal device 11 transmits the grouped frames (data frame DF and parity frame PF) to the terminal device 12 via the FC-SW13 in a predetermined order.

[0037] The reception control unit 22 will be described. When the frame loss detection unit 41 receives a plurality of frames from a terminal device (the terminal device on the transmission side) via the FC-SW, it detects whether there is a frame loss for each group (the second group).

[0038] Specifically, the frame loss detection unit 41 of the reception control unit 22 of the terminal device 12 executes the process T3a shown in FIG. 3. In the process T3a, the frame loss detection unit 41 first acquires frames (data frame DF and parity frame PF) from the FC-SW13 shown in FIG. 3.

[0039] Next, the frame loss detection unit 41 compares the sequence number included in the header of the latest frame transmitted from the terminal device 11 with the sequence number included in the header of the frame that has already been received.

[0040] Next, the frame loss detection unit 41 determines, for each group Gr1, Gr2,... based on the comparison result, whether there is a frame that has not been received among the frames transmitted from the terminal device 11.

[0041] In the example of FIG. 3, the data frame DF included in the group Gr1 disappears (the × mark in FIG. 3) when transmitted from the FC-SW13 to the terminal device 12 and cannot be received by the terminal device 12 (the broken line range in FIG. 3).

[0042] In such a case, the frame loss detection unit 41 detects that a frame loss has occurred in the data frame DF and gives an instruction to the frame restoration unit 42 to restore the data frame DF.

[0043] When the frame loss of the data frame DF is detected, the frame restoration unit 42 restores the frame with the frame loss based on the parity frame included in the group. Specifically, the frame restoration unit 42 of the reception control unit 22 of the terminal device 12 executes the process T4 shown in FIG. 3.

[0044] In process T4, first, after the frame restoration unit 42 obtains an instruction to restore the data frame DF, it acquires the parity frame PF of group Gr1 including the frame in which frame loss has occurred.

[0045] Next, the frame restoration unit 42 restores the data frame DF (thick line range) with frame loss by error correction processing (black arrow in FIG. 3).

[0046] Examples of the process for restoring the data frame DF with frame loss include error correction processing using Hamming codes. However, the process for restoring the data frame DF with frame loss is not limited to error correction processing using Hamming codes.

[0047] The parity frame deletion unit 43 deletes the parity frame from the group. Specifically, the parity frame deletion unit 43 of the reception control unit 22 of the terminal device 12 executes the process T5 shown in FIG. 3.

[0048] In process T5, when the parity frame deletion unit 43 detects that the data frame DF with frame loss has been restored by the frame restoration unit 42, it deletes the parity frame PF (broken line range) from groups Gr1, Gr2, ···

[0049] After the parity frame is deleted from each group, the transmission source data generation unit 44 generates transmission source data using the frames of the group.

[0050] Specifically, the transmission source data generation unit 44 executes the process T6 shown in FIG. 3. In process T6, the transmission source data generation unit 44 generates (restores) the data D transmitted by the terminal device 11 using the data of the data frames DF included in groups Gr1, Gr2, ···

[0051] The operation in normal times will be described. During normal operation, since there is no frame loss, there is no need to restore the frame. Therefore, the parity frame deletion unit 43 deletes the parity frame from the group during normal operation.

[0052] Specifically, the frame loss detection unit 41 of the reception control unit 22 of the terminal device 12 executes the process T3b shown in FIG. 4. FIG. 4 is a diagram for explaining the operation of the FC communication system during normal operation.

[0053] In process T3b, the frame loss detection unit 41 first acquires frames (data frame DF and parity frame PF) from the FC-SW13 shown in FIG. 4.

[0054] Next, the frame loss detection unit 41 compares the sequence number included in the header of the latest frame transmitted from the terminal device 11 with the sequence number included in the header of the frame that has already been received.

[0055] Next, based on the comparison result, the frame loss detection unit 41 determines whether there is an unreceived frame among the frames transmitted from the terminal device 11 for each group Gr1, Gr2, ···.

[0056] As in the example of FIG. 4, when it is determined that there is no frame loss, since no frame loss has occurred, the frame loss detection unit 41 gives a restoration instruction for restoring the data D to the parity frame deletion unit 43 and the transmission source data generation unit 44.

[0057] Next, the parity frame deletion unit 43 of the reception control unit 22 of the terminal device 12 acquires the restoration instruction. Next, the parity frame deletion unit 43 executes the above-described process T5 shown in FIG. 4 to delete the parity frame PF from each of the groups Gr1, Gr2, ···.

[0058] Next, the transmission source data generation unit 44 of the reception control unit 22 of the terminal device 12 executes the above-described process T6 shown in FIG. 4, and generates (restores) the data D transmitted by the terminal device 11 using the data of the data frame DF possessed by the groups Gr1, Gr2,....

[0059] The operation in the case of parity frame loss will be described. When the frame loss detection unit 41 detects a frame loss of only the parity frame in the target group, the parity frame deletion unit 43 does not need to delete the parity frame PF of the target group because it has suffered a frame loss. Note that the parity frame PF of groups other than the target group is deleted.

[0060] Specifically, the frame loss detection unit 41 of the reception control unit 22 of the terminal device 12 executes the process T3c shown in FIG. 5. FIG. 5 is a diagram for explaining the operation of the FC communication system in the case of parity frame loss.

[0061] In process T3c, the frame loss detection unit 41 first acquires frames (data frame DF and parity frame PF) from the FC-SW13 shown in FIG. 5.

[0062] Next, the frame loss detection unit 41 compares the sequence number included in the header of the latest frame transmitted from the terminal device 11 with the sequence number included in the header of the frame that has already been received.

[0063] Next, the frame loss detection unit 41 determines, for each of the groups Gr1, Gr2,..., whether there is a frame that has not been received among the frames transmitted from the terminal device 11 based on the comparison result.

[0064] As in the example of FIG. 5, when it is detected that there is no frame loss in the data frame DF and only the parity frame PF has suffered a frame loss in the same group Gr1, the frame loss detection unit 41 gives an instruction to restore the data D to the parity frame deletion unit 43 and the transmission source data generation unit 44.

[0065] When the parity frame deletion unit 43 obtains the above-described restoration instruction from the frame loss detection unit 41, since the parity frame PF of group Gr1 has already suffered frame loss, it may not be necessary to delete it. Note that the parity frames PF of groups Gr2... other than group Gr1 are each deleted.

[0066] Next, the transmission source data generation unit 44 of the reception control unit 22 of the terminal device 12 executes the above-described process T6 shown in FIG. 5. In process T6, the transmission source data generation unit 44 generates (restores) the data D transmitted by the terminal device 11 using the data of the data frames DF included in groups Gr1, Gr2...

[0067] As described above, in the present embodiment, in FC-SAN, even when frame loss occurs, if the frame can be restored, communication can be performed without retransmission.

[0068] In addition, when frame loss occurs, since the frame can be restored without retransmitting the frame in terms of the exchange unit, the processing time for retransmission can be reduced.

[0069] In addition, since the data frame with frame loss can be restored without newly adding hardware to the FC-SW, the cost can be reduced.

[0070] [Device Operation] Next, the operation of the communication control device in the present embodiment will be described with reference to FIGS. 6 and 7. FIG. 6 is a diagram for explaining an example of the operation of the transmission control unit of the communication control device. FIG. 7 is a diagram for explaining an example of the operation of the reception control unit of the communication control device. In the following description, reference will be made to the drawings as appropriate.

[0071] In addition, in the present embodiment, by operating the communication control device, the communication control method is implemented. Therefore, the description of the communication control method in the present embodiment will be replaced with the following description of the operation of the communication control device.

[0072] Describe the operation of the transmission control unit. The group generation unit 31 of the transmission control unit 21 of the terminal device 11 shown in FIG. 1 first executes the process T1 shown in FIG. 3.

[0073] In process T1, when the group generation unit 31 transmits a plurality of frames to the terminal device 12 (the receiving-side terminal device) via the FC-SW13 in the FC-SAN, the group generation unit 31 collects a preset number of frames and generates a group (the first group).

[0074] Specifically, the group generation unit 31 first acquires data D (transmission source data) from an upper layer such as SCSI (Small Computer System Interface) (step A1).

[0075] Next, the group generation unit 31 divides the data D into data of a preset size, and generates a data frame DF for each divided data (step A2).

[0076] Thereafter, the group generation unit 31 collects a preset number of data frames DF and generates groups Gr1, Gr2,... (step A3).

[0077] Next, the parity frame generation unit 32 of the transmission control unit 21 of the terminal device 11 shown in FIG. 1 executes the process T2 shown in FIG. 3.

[0078] In process T2, the parity frame generation unit 32 generates a parity frame (the first parity frame) for each group based on the data included in the group (step A4). Then, the parity frame addition unit 33 adds the generated parity frame to a preset position of the group (step A5).

[0079] Specifically, in step A4, the parity frame generation unit 32 first generates a parity frame PF for each of the groups Gr1, Gr2,... based on the divided data included in the group.

[0080] Next, in step A5, the parity frame addition unit 33 adds the parity frames PF generated for each of the groups Gr1, Gr2,... from the parity frame generation unit 32 to the preset positions of the corresponding groups.

[0081] Note that the headers of the data frame DF and the parity frame PF include sequence numbers.

[0082] Next, when the above-described processes T1 and T2 are completed, the terminal device 11 transmits the grouped frames (data frame DF and parity frame PF) to the terminal device 12 via the FC-SW13 in a predetermined order (step A6).

[0083] The operation of the reception control unit will be described. The frame loss detection unit 41 of the reception control unit 22 of the terminal device 12 shown in FIG. 1 executes the process T3a shown in FIG. 3, the process T3b shown in FIG. 4, and the process T3c shown in FIG. 5.

[0084] When the frame loss detection unit 41 receives a plurality of frames from the terminal device 11 (the transmitting-side terminal device) via the FC-SW13, it detects whether there is a frame loss for each group (the second group).

[0085] Specifically, the frame loss detection unit 41 first acquires frames (data frame DF and parity frame PF) from the FC-SW13 (step B1).

[0086] Next, the frame loss detection unit 41 determines whether there is a frame loss in the received frames (step B2).

[0087] Specifically, in step B2, the frame loss detection unit 41 compares the sequence number included in the header of the latest frame transmitted from the terminal device 11 with the sequence number included in the header of the frame that has already been received, and based on the comparison result, determines for each of the groups Gr1, Gr2, ··· whether there is an unreceived frame among the frames transmitted from the terminal device 11.

[0088] Next, when it is determined that there is no frame loss (step B2: No), that is, when it is normal, the frame loss detection unit 41 gives an instruction to restore the data D to the parity frame deletion unit 43 and the transmission source data generation unit 44 (process T3b). Then, the process of step B5 is executed.

[0089] Also, when it is determined that there is a frame loss (step B2: Yes), in the same group, it is determined whether the frame that has suffered a frame loss is only the data frame DF, only the parity frame PF, or both the data frame DF and the parity frame PF (determine the type of frame loss) (step B3).

[0090] When the frame loss is only the data frame DF (step B3: determination 1), the frame loss detection unit 41 gives an instruction to restore the data D to the frame restoration unit 42, the parity frame deletion unit 43, and the transmission source data generation unit 44 (process T3a). Then, the process of step B4 is executed.

[0091] Also, when the frame that has suffered a frame loss is only the parity frame PF (step B3: determination 2), the frame loss detection unit 41 gives an instruction to restore the data D to the parity frame deletion unit 43 and the transmission source data generation unit 44 (process T3c). Then, the process of step B5 is executed.

[0092] Also, when the frame that has suffered a frame loss is both the data frame DF and the parity frame PF (step B3: determination 3), the frame loss detection unit 41 discards the frame and waits for retransmission (step B7).

[0093] In step B4, when the frame restoration unit 42 detects a frame loss in the data frame, it restores the frame with the frame loss based on the parity frames included in the group.

[0094] Specifically, in step B4, the frame restoration unit 42 of the reception control unit 22 of the terminal device 12 executes the process T4 shown in FIG. 3. In process T4, first, after the frame restoration unit 42 obtains a restoration instruction for the data frame DF, it obtains the parity frame PF of the group Gr1 including the frame in which the frame loss has occurred.

[0095] Next, the frame restoration unit 42 restores the data frame DF with the frame loss (thick line range) by error correction processing (black arrow in FIG. 3).

[0096] In step B5, the parity frame deletion unit 43 deletes the parity frame from the group. Specifically, in step B5, the parity frame deletion unit 43 of the reception control unit 22 of the terminal device 12 executes process T5.

[0097] When there is no frame loss (normal), the parity frame deletion unit 43 deletes the parity frames of each group.

[0098] When a frame loss occurs only in the data frame DF in the target group, after the data frame DF with the frame loss is restored by the frame restoration unit 42, the parity frame deletion unit 43 deletes the parity frame PF of the target group.

[0099] When a frame loss occurs only in the parity frame PF in the target group, since the parity frame PF of the target group has a frame loss, it does not need to be deleted. Note that the parity frames PF of groups other than the target group are deleted.

[0100] In step B6, after the parity frame is deleted from each group, the source data generation unit 44 generates source data using the frames of the group. Specifically, in step B6, the source data generation unit 44 executes process T6.

[0101] In process T6, the source data generation unit 44 generates (restores) the data D transmitted by the terminal device 11 using the data of the data frame DF of each group.

[0102] In step B7, the terminal device 12 discards the frame and waits for the frame to be retransmitted from the terminal device 11. Specifically, in step B7, after a timeout, the terminal device 12 waits for the frame to be retransmitted from the terminal device 11. Then, it proceeds to step B1 to execute the process.

[0103] Note that in the above example, the terminal device 11 is used as the transmitting terminal device and the terminal device 12 is used as the receiving terminal device. However, the terminal device 12 may be used as the transmitting terminal device and the terminal device 11 may be used as the receiving terminal device.

[0104] [Effect of this Embodiment] As described above, according to this embodiment, in a storage area network using a fiber channel, even if a frame loss occurs and the frame can be restored, communication can be performed without retransmission.

[0105] Also, when a frame loss occurs, since the frame can be restored without retransmitting the frame in units of exchange, the processing time for retransmission can be reduced.

[0106] In addition, since the data frame with frame loss can be restored without newly adding hardware to the FC-SW, the cost can be reduced.

[0107] [Program] The program in the embodiment of the present invention may be any program that causes a computer to execute steps A1 to A6 shown in FIG. 6 and steps B1 to B7 shown in FIG. 7. By installing and executing this program on a computer, the communication control device and the communication control method in the present embodiment can be realized.

[0108] In this case, the processor of the computer functions as the transmission control unit 21 (group generation unit 31, parity frame generation unit 32, parity frame addition unit 33) and the reception control unit 22 (frame loss detection unit 41, frame restoration unit 42, parity frame deletion unit 43, transmission source data generation unit 44), and performs processing.

[0109] Also, the program in the present embodiment may be executed by a computer system constructed by a plurality of computers. In this case, for example, each computer may function as either the transmission control unit 21 (group generation unit 31, parity frame generation unit 32, parity frame addition unit 33) or the reception control unit 22 (frame loss detection unit 41, frame restoration unit 42, parity frame deletion unit 43, transmission source data generation unit 44).

[0110] [Physical Configuration] Here, the computer that realizes the communication control device by executing the program in the present embodiment will be described with reference to FIG. 8. FIG. 8 is a block diagram showing an example of a computer that realizes the communication control device in the present embodiment.

[0111] As shown in FIG. 8, the computer 110 includes a CPU 111, a main memory 112, a storage device 113, an input interface 114, a display controller 115, a data reader / writer 116, and a communication interface 117. These components are connected to each other via a bus 121 so as to be able to communicate with each other. Note that the computer 110 may include a GPU or an FPGA in addition to or instead of the CPU 111.

[0112] The CPU 111 expands the program (code) in this embodiment stored in the storage device 113 into the main memory 112, and executes these in a predetermined order to perform various operations. The main memory 112 is typically a volatile storage device such as a DRAM (Dynamic Random Access Memory). Further, the program in this embodiment is provided in a state stored in a computer-readable recording medium 120. Note that the program in this embodiment may be distributed on the Internet connected via the communication interface 117. Note that the recording medium 120 is a non-volatile recording medium.

[0113] In addition, specific examples of the storage device 113 include a hard disk drive and a semiconductor storage device such as a flash memory. The input interface 114 mediates data transmission between the CPU 111 and an input device 118 such as a keyboard and a mouse. The display controller 115 is connected to the display device 119 and controls the display on the display device 119.

[0114] The data reader / writer 116 mediates data transmission between the CPU 111 and the recording medium 120, and executes reading of the program from the recording medium 120 and writing of the processing result in the computer 110 to the recording medium 120. The communication interface 117 mediates data transmission between the CPU 111 and another computer.

[0115] In addition, specific examples of the recording medium 120 include general-purpose semiconductor memory devices such as CF (Compact Flash (registered trademark)) and SD (Secure Digital), magnetic recording media such as a flexible disk, or optical recording media such as a CD-ROM (Compact Disk Read Only Memory).

[0116] Note that the communication control device in this embodiment can also be realized by using hardware corresponding to each part, rather than a computer installed with a program. Furthermore, part of the communication control device may be realized by a program and the remaining part may be realized by hardware.

[0117] [Appendix] Regarding the above embodiments, the following appendices are further disclosed. Some or all of the above-described embodiments can be expressed by (Appendix 1) to (Appendix 18) described below, but are not limited to the following description.

[0118] (Appendix 1) In a storage area network using a fiber channel, when transmitting a plurality of first data frames to a receiving terminal device via a fiber channel switch, a group generation unit that collects a preset number of the first data frames to generate a first group; a parity frame generation unit that generates a first parity frame for each first group based on the data of the first data frames included in the first group; a parity frame addition unit that adds the first parity frame to a preset position of the first group; A communication control device having the above.

[0119] (Appendix 2) The communication control device according to Appendix 1, when receiving frames for each second group from a transmitting terminal device via the fiber channel switch, a frame loss detection unit that detects whether there is a frame loss for each second group; when detecting a frame loss of a second data frame included in the second group, a frame restoration unit that restores the frame-lost second data frame based on a second parity frame included in the second group; A communication control device having the above.

[0120] (Appendix 3) A communication control device according to Appendix 2, a parity frame deletion unit that deletes a second parity frame from the second group when there is no frame loss in the second group; a transmission source data generation unit that generates transmission source data using the second data frames of the second group after the second parity frame is deleted from the second group; A communication control device having the above.

[0121] (Appendix 4) A communication control device according to Appendix 3, wherein the parity frame deletion unit deletes a second parity frame from the second group after the second data frame with frame loss is restored; A communication control device.

[0122] (Appendix 5) A communication control device according to Appendix 3 or 4, wherein when only the frame loss of the second parity frame is detected in the second group by the frame loss detection unit, the parity frame deletion unit deletes the second parity frame of the second group in which the frame loss of the second parity frame has not been detected; A communication control device.

[0123] (Appendix 6) In a storage area network using a fiber channel, when transmitting a plurality of first data frames to a receiving terminal device via a fiber channel switch, a group generation step of collecting a preset number of the first data frames to generate a first group; a parity frame generation step of generating a first parity frame for each first group based on the data of the first data frames included in the first group; a parity frame addition step of adding the first parity frame to a preset position of the first group; A communication control method having

[0124] (Appendix 7) The communication control method according to Appendix 6, wherein when receiving frames for each second group from a transmitting terminal device via the fiber channel switch, a frame loss detection step of detecting whether there is a frame loss for each received second group of frames; when detecting a frame loss of a second data frame included in the second group, a frame restoration step of restoring the data frame with the frame loss based on a second parity frame included in the second group; A communication control method having

[0125] (Appendix 8) The communication control method according to Appendix 7, wherein the program causes the computer to when there is no frame loss in the second group, a parity frame deletion step of deleting a second parity frame from the second group; after the second parity frame is deleted from the second group, a transmitted source data generation step of generating transmitted source data using the second data frames of the second group; A communication control method having

[0126] (Appendix 9) The communication control method according to Appendix 8, wherein in the parity frame deletion step, after the second data frame with the frame loss is restored, the second parity frame is deleted from the second group A communication control method.

[0127] (Appendix 10) The communication control method according to Appendix 8 or 9, wherein In the frame loss detection step, if only the frame loss of the second parity frame is detected in the second group, in the parity frame deletion step, delete the second parity frame of the second group in which the frame loss of the second parity frame is not detected. Communication control method.

[0128] (Appendix 11) To a computer, In a storage area network using a fiber channel, when transmitting a plurality of first data frames to a receiving terminal device via a fiber channel switch, a group generation step of collecting the first data frames of a preset number to generate a first group; A parity frame generation step of generating a first parity frame for each first group based on the data of the first data frames included in the first group; A parity frame addition step of adding the first parity frame to a preset position of the first group; A program including instructions to cause the above to be executed.

[0129] (Appendix 12) The program according to Appendix 11, wherein the program causes the computer to When receiving frames for each second group from a transmitting terminal device via the fiber channel switch, a frame loss detection step of detecting whether there is a frame loss for each received second group; When detecting a frame loss of a second data frame included in the second group, a frame restoration step of restoring the frame-lost second data frame based on a second parity frame included in the second group; A program including instructions to cause the above to be executed.

[0130] (Appendix 13) The program according to Supplementary Note 12, wherein when the program causes the computer to when there is no frame loss in the second group, a parity frame deletion step of deleting a second parity frame from the second group; after the second parity frame is deleted from the second group, a source data generation step of generating source data using the second data frames of the second group; A program including instructions to execute.

[0131] (Supplementary Note 14) The program according to Supplementary Note 13, wherein in the parity frame deletion step, after the second data frame with frame loss is restored, the second parity frame is deleted from the second group Program.

[0132] (Supplementary Note 15) The program according to Supplementary Note 13 or 14, wherein when only the frame loss of the second parity frame is detected in the second group by the frame loss detection step, in the parity frame deletion step, the second parity frame of the second group in which the frame loss of the second parity frame has not been detected is deleted Program.

[0133] (Supplementary Note 16) A communication system of a storage area network using a fiber channel, wherein a first terminal device when transmitting a plurality of first data frames to a second terminal device via a fiber channel switch, generates a first group by collecting a preset number of the first data frames, generates a first parity frame for each first group based on the data of the first data frames included in the first group, Add the first parity frame to the preset position of the first group Transmit a plurality of frames to a second terminal device via a fiber channel switch, The second terminal device, When receiving a plurality of frames from the first terminal device via the fiber channel switch, detect whether there is a frame loss for each second group, When detecting a frame loss of a second data frame included in the second group, restore the second data frame with the frame loss based on a second parity frame included in the second group, After the second data frame with the frame loss is restored, delete the second parity frame from the second group, After the second parity frame is deleted from the second group, generate transmission source data using the second data frame of the second group Communication system.

[0134] (Appendix 17) The communication system according to Appendix 16, wherein The second terminal device, When there is no frame loss in the second group, delete the second parity frame from the second group, After the second parity frame is deleted from the second group, generate transmission source data using the second data frame of the second group Communication system.

[0135] (Appendix 18) The communication system according to Appendix 16 or 17, wherein In the second group, when only a frame loss of the second parity frame is detected, the parity frame deletion unit deletes a second parity frame of a second group in which no frame loss of the second parity frame is detected Communication system.

[0136] The present invention has been described with reference to the embodiments above, but the present invention is not limited to the above embodiments. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

Industrial Applicability

[0137] As described above, according to the present invention, in a storage area network using a fiber channel, even if a frame loss occurs and the frame can be restored, communication can be performed without retransmission. The present invention is useful in the field of using FC-SAN.

Explanation of Signs

[0138] 10 FC communication system 11 Terminal device (server) 12 Terminal device (storage) 13 FC-SW 20 Communication control device 21 Transmission control unit 22 Reception control unit 31 Group generation unit 32 Parity frame generation unit 33 Parity frame addition unit 41 Frame loss detection unit 42 Frame restoration unit 43 Parity frame deletion unit 44 Transmission source data generation unit 110 Computer 111 CPU 112 Main memory 113 Storage device 114 Input interface 115 Display controller 116 Data reader / writer 117 Communication interface 118 Input device 119 Display device 120 Recording medium 121 Bus

Claims

1. In a storage area network using a fiber channel, when transmitting a plurality of first data frames to a receiving terminal device via a fiber channel switch, a group generation means for collecting a preset number of the first data frames to generate a first group; A parity frame generation means for generating a first parity frame for each of the first groups based on the data of the first data frames included in the first group; A parity frame addition means for adding the first parity frame to a preset position of the first group; When receiving frames for each second group from a transmitting terminal device via the fiber channel switch, a frame loss detection means for detecting whether there is a frame loss for each second group; When detecting a frame loss of a second data frame included in the second group, a frame restoration means for restoring the second data frame with the frame loss based on a second parity frame included in the second group; A communication control device having the above.

2. The communication control device according to claim 1, A parity frame deletion means for deleting a second parity frame from the second group when there is no frame loss in the second group; After the second parity frame is deleted from the second group, a transmission source data generation means for generating transmission source data using the second data frames of the second group; A communication control device having the above.

3. The communication control device according to claim 2, The parity frame deletion means deletes a second parity frame from the second group after the second data frame with the frame loss is restored. Communication control device.

4. The communication control device according to claim 2 or 3, When only a frame loss of the second parity frame is detected in the second group by the frame loss detection means, the parity frame deletion means deletes the second parity frame of the second group in which no frame loss of the second parity frame is detected. Communication control device.

5. In a storage area network using a fiber channel, when transmitting a plurality of first data frames to a receiving-side terminal device via a fiber channel switch, a preset number of the first data frames are collected to generate a first group, Based on the data of the first data frames included in the first group, a first parity frame is generated for each first group, The first parity frame is added to a preset position of the first group, When receiving frames for each second group from a transmitting-side terminal device via the fiber channel switch, it is detected whether there is a frame loss for each received second group, When detecting a frame loss of a second data frame included in the second group, the lost second data frame is restored based on a second parity frame included in the second group, Communication control method. Claim 6 In a computer, In a storage area network using a fiber channel, when transmitting a plurality of first data frames to a receiving-side terminal device via a fiber channel switch, a preset number of the first data frames are collected to generate a first group, Based on the data of the first data frames included in the first group, a first parity frame is generated for each first group, The first parity frame is added to a preset position of the first group, When receiving frames for each second group from a transmitting-side terminal device via the fiber channel switch, it is detected whether there is a frame loss for each received second group, When detecting a frame loss of a second data frame included in the second group, the lost second data frame is restored based on a second parity frame included in the second group, A program including instructions for causing the processing to be executed. Claim 7 A communication system for a storage area network using a fiber channel, The first terminal device, When transmitting a plurality of first data frames to a second terminal device via a fiber channel switch, a preset number of the first data frames are collected to generate a first group, Based on the data of the first data frame included in the first group, generate a first parity frame for each first group, Add the first parity frame to a preset position of the first group Transmit a plurality of frames to a second terminal device via a fiber channel switch, The second terminal device is When receiving a plurality of frames from the first terminal device via the fiber channel switch, detect whether there is a frame loss for each second group, When detecting a frame loss of the second data frame included in the second group, restore the second data frame with the frame loss based on the second parity frame included in the second group, After the second data frame with the frame loss is restored, delete the second parity frame from the second group, After the second parity frame is deleted from the second group, generate source data using the second data frame of the second group Communication system.

Images