JP2012244490A - Data transmission-side communication device and program, data reception-side communication device and program, and communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication system capable of achieving efficient multilink communication between communication devices only by a simple procedure without setting transmission performance, transmission content, etc. in advance.SOLUTION: The communication system includes a data reception-side communication device and a data transmission-side communication device for transmitting a transmission packet by communication through a plurality of bundled routes. The data transmission-side communication device includes: means for forwarding a transmission packet having sequence number information to any one of the routes; means for receiving an arrival notification from the data reception-side communication device; and means for determining a forwarding ratio to each route according to the reception condition of the route-by-route arriving notification, to control to forward with a determined forwarding ratio. The data reception-side communication device includes means for transmitting an arrival notification, including the sequence number information of a received transmission packet, to the data transmission-side communication device.

Description

  The present invention relates to a data transmission side communication device and program, a data reception side communication device and program, and a communication system. For example, communication (multilink communication) in which transmission bands of a plurality of paths are bundled between communication devices is performed. It can be applied to a communication system that can.

  Conventionally, as a technique for realizing multilink communication between communication apparatuses by using a transport layer without being influenced by specifications of a physical layer, there is a technique described in Patent Document 1.

  Further, the technology described in Patent Document 2 describes that in multilink communication using a plurality of routes (network media), delay information and the like are detected in advance for each route and used for bandwidth allocation. .

JP 2001-60956 A JP 2006-60579 A

  However, when multilink communication is realized by using conventional techniques (such as channel bonding) such as the technique described in Patent Document 1, sorting is performed based on a specific packet structure (by IP address, by MAC address, etc.). For example, a specific setting operation was required for route allocation. Further, in the prior art such as Patent Document 1, it is not used effectively depending on the structure of a packet that actually passes (for example, only a specific channel is used if the value specified for distribution is biased in practice). In addition, it is necessary to set the performance after predefining the performance of each transmission path.

  In addition, in the technology described in Patent Document 2, it is necessary to have and control a plurality of functional blocks in order to realize the operation. For example, it is difficult to handle because of complicated processing. It has been difficult to apply to the communication equipment.

  In view of the above-described problems, a data transmission side communication device and program capable of realizing efficient multilink communication without performing prior settings such as transmission performance and transmission contents in a simple procedure, and A data receiving side communication device and program, and a communication system are desired.

  The first aspect of the present invention includes a data reception side communication device and a data transmission side communication device that transmits a plurality of transmission packets into which data is inserted to a data reception side communication device by communication in which a plurality of paths are bundled. In the communication system, (1) the data transmission side communication device includes (1-1) transmission packet holding means for holding a plurality of transmission packets to which serial number information is assigned, and (1-2) holding the transmission packet. A transmission packet transmitting means for transmitting the transmission packet held by the means to the data receiving communication device using any one of the routes in the order of serial numbers; and (1-3) reaching the data receiving communication device. Notification receiving means for receiving from the data receiving side communication device an arrival notification including information on the serial number of the transmitted packet, and (1-4) reception of the arrival notification for each route. Transmission for controlling the transmission packet transmitting means so that the transmission rate for the transmission packet to be transmitted to each of the routes is determined according to the situation, and the transmission packet is transmitted to each of the routes at the determined transmission rate. (2) the data reception side communication device includes (2-1) a transmission packet reception unit that receives a transmission packet sent from the data transmission side communication device, and (2-2) And a transmission means for extracting serial number information from the transmission packet received by the transmission packet receiving means and transmitting an arrival notification including the serial number information to the data transmission side communication device.

  According to a second aspect of the present invention, there is provided a data transmission side communication device that transmits a plurality of transmission packets into which data is inserted to a data reception side communication device by communication in which a plurality of paths are bundled. A transmission packet holding means for holding a plurality of assigned transmission packets; and (2) the transmission packets held by the transmission packet holding means in the order of serial numbers using any one of the routes, the data receiving side communication (3) a notification receiving means for receiving an arrival notification including information on a serial number of a transmission packet that has arrived at the data receiving communication device from the data receiving communication device; ) According to the reception status of the arrival notification for each route, the sending rate for the transmission packets sent to each route is determined, and the determined sending rate As transmission packet to each of the pathways it is transmitted, and having a transmission packet transmission control means for controlling the transmission packet transmitting means.

  According to a third aspect of the present invention, there is provided a data reception side communication device that receives a transmission packet from a data transmission side communication device that transmits a plurality of transmission packets into which data is inserted by communication in which a plurality of paths are bundled. A transmission packet receiving means for receiving a transmission packet including serial number information sent from the data transmitting side communication device; and (2) extracting the serial number information from the transmission packet received by the transmission packet receiving means, And a notification transmission unit configured to transmit an arrival notification including the serial number information to the transmission-side communication device.

  According to a fourth aspect of the present invention, there is provided a data transmission side communication program for (1) a data transmission side communication device that transmits a plurality of transmission packets having data inserted to a data reception side communication device by communication in which a plurality of paths are bundled. (2) a transmission packet holding means for holding a plurality of transmission packets assigned serial number information; and (3) a transmission packet for holding a plurality of transmission packets assigned serial number information. (4) transmission packet transmission means for sending the transmission packets held by the transmission packet holding means to the data receiving side communication device using any one of the paths in the order of serial numbers; ) A communication that receives from the data receiving communication device an arrival notification including information on the serial number of the transmission packet that has reached the data receiving communication device. (6) A transmission rate for transmission packets to be sent to each of the routes is determined according to the reception status of arrival notification for each route, and a transmission packet is sent to each of the routes at the determined transmission rate. It is made to function as a transmission packet transmission control means for controlling the transmission packet transmission means so as to be transmitted.

  A data reception side communication program according to a fifth aspect of the present invention provides: (1) Data for receiving a transmission packet from a data transmission side communication device that transmits a plurality of transmission packets into which data is inserted by communication in which a plurality of paths are bundled. (2) a transmission packet receiving means for receiving a transmission packet including serial number information sent from the data transmitting side communication apparatus; and (3) the transmission packet receiving means. It is characterized in that serial number information is extracted from the received transmission packet and functions as a notification transmission means for transmitting an arrival notification including the serial number information to the data transmission side communication device.

  According to the present invention, it is possible to provide a communication system capable of realizing efficient multi-link communication between communication devices with simple procedures and without performing prior setting of transmission performance, transmission content, and the like. .

It is the block diagram shown about the structure of the communication system which concerns on embodiment. It is explanatory drawing shown about the example of the content of the path | route management table of the data transmission side communication apparatus which concerns on embodiment. It is the flowchart (the 1) shown about operation | movement of the communication control part which comprises the data transmission side communication apparatus which concerns on embodiment. It is the flowchart (the 2) shown about operation | movement of the communication control part which comprises the data transmission side communication apparatus which concerns on embodiment. It is the flowchart (the 3) shown about operation | movement of the communication control part which comprises the data transmission side communication apparatus which concerns on embodiment. It is the timing chart shown about communication between the data transmission side communication apparatus and data reception side communication apparatus which concern on embodiment. It is explanatory drawing shown about the transition of the content of the path | route management table in the data transmission side communication apparatus which concerns on embodiment.

(A) Main Embodiments Hereinafter, an embodiment of a data transmission side communication device and program, a data reception side communication device and program, and a communication system according to the present invention will be described in detail with reference to the drawings.

(A-1) Configuration of Embodiment FIG. 1 is a block diagram showing an overall configuration of a communication system 10 of this embodiment.

  The communication system 10 includes a data transmission side communication device 20 and a data reception side communication device 30.

  The data transmission side communication device 20 is a communication device capable of transmitting a packet in which data is inserted to the data reception side communication device 30 via the network N. The data reception side communication device 30 receives data (packets) transmitted from the data transmission side communication device 20. The format of packets transmitted and received between the data transmission side communication device 20 and the data reception side communication device 30 (packet format on the network layer) is not limited, but here, IP packets are used. Will be described.

  The data transmission side communication device 20 includes a control unit 21, a transmission / reception unit 22, a communication control unit 24, and a path management table 25.

  The data transmission side communication device 20 includes a program execution configuration such as a CPU, ROM, RAM, EEPROM, hard disk, etc., and a device having a network interface (not limited to one, but capable of distributed processing of a plurality of devices) May be constructed by installing the data transmission side communication program or the like of the embodiment, and even in that case, it can be functionally shown as in FIG. .

  The control unit 21 has a function of controlling the entire data transmission side communication device 20.

  The transmission / reception unit 22 has an interface function for connecting to the network N. Here, it is assumed that the transmission / reception unit 22 includes three interfaces 23 (23-1 to 23-3) each connected to the network N. Note that the number and types of the interfaces 23 included in the transmission / reception unit 22 are not limited. In addition, here, in order to simplify the description, all the interfaces 23 communicate with the data transmission side communication device 20 via the network N, but data transmission is performed via different networks for each interface 23. You may make it communicate with the side communication apparatus 20. FIG. Each interface 23 may be configured as a physical interface (for example, one Ethernet (registered trademark) port), or may be configured by dividing one physical interface into a plurality of channels (for example, ATM, VPN, etc.). The connection may be made using a logical path. Here, the interfaces 23-1 to 23-3 will be described as having different speeds that can be connected to the network N.

  Each interface 23 receives the transmission packet supplied from the communication control unit 24 and sends the packet to the network N. Further, each interface 23 receives the packet addressed to the transmission side communication device 20 from the network N, and delivers the packet to the communication control unit 24.

  The communication control unit 24 has a function of performing control related to packet transmission / reception in the data transmission side communication device 20. When the transmission data to be transmitted from the data transmission side communication device 20 to the data reception side communication device 30 is generated, the communication control unit 24 generates the packet while holding the data, To the interface 23. The trigger and contents of the data to be transmitted from the data transmission side communication device 20 to the data reception side communication device 30 are not limited. For example, the upper layer processing configuration (not shown) in the data transmission side communication device 20 ( For example, a case where the error occurs in an application or the like. Further, when the packet received by any one of the interfaces 23 is a packet for communication control addressed to the data transmission side communication device 20, the communication control unit 24 holds and processes the packet.

  When transmitting a packet to the data reception side communication device 30, the communication control unit 24 bundles a plurality of paths (paths 1 to 3) and performs packet transmission by multilink communication.

  Which path (interface 23) is used when the communication control unit 24 transmits a packet (hereinafter referred to as “transmission packet”) into which data is inserted by multilink communication to the data receiving side communication device 30. The selected transmission packet is delivered to the selected interface 23. The control of multilink communication performed between the data transmission side communication device 20 (communication control unit 24) and the data reception side communication device 30 (communication control unit 34) is performed for each session in the transport layer, for example. For these layers (network layer, data link layer, etc.), the same configuration as that of the existing IP network may be applied. Here, the multilink communication performed between the data transmission side communication device 20 (communication control unit 24) and the data reception side communication device 30 (communication control unit 34) will be mainly described. As described above, since it is possible to apply the same as the existing IP network as described above, detailed description thereof will be omitted.

  In the following description, the route for transmitting data from the data transmission side communication device 20 to the data reception side communication device 30 using the interface 23-1 is “route 1”, and the data is transmitted to the data reception side communication device 30 using the interface 23-2. A route for transmission is referred to as “route 2”, and a route for transmitting data to the data reception side communication device 30 using the interface 23-3 is referred to as “route 3”. In the following description, it is assumed that the route numbers 1 to 3 are assigned to the routes 1 to 3, respectively.

  Further, as described above, the data transmission side communication device 20 can perform data transmission to the data reception side communication device 30 by multilink communication using the paths 1 to 3. At that time, the communication control unit 24 also performs control such as distribution of transmission packets to each path. Specifically, the communication control unit 24 updates the contents of a route management table 25 described later according to the communication status with the data receiving side communication device 30. Then, the communication control unit 24 determines the ratio (transfer ratio) of transmission packets to be supplied for each path based on the contents of the path management table 25, and sends data packets to each path (at a ratio according to the determined transfer ratio). Assign to interface 23). The process in which the communication control unit 24 determines the transfer rate for each path and the contents of the path management table 25 will be described later.

  The data reception side communication device 30 includes a data reception side communication device 30, a control unit 31, a transmission / reception unit 32, and a communication control unit 34.

  The data receiving side communication device 30 has a program execution configuration such as a CPU, ROM, RAM, EEPROM, hard disk, etc., and a device having a network interface (not limited to one, but capable of distributed processing of a plurality of devices) May be constructed by installing the data receiving side communication program of the embodiment, and even in that case, it can be functionally shown as in FIG.

  The control unit 31 has a function of controlling the entire data receiving side communication device 30.

  The transmission / reception unit 32 has an interface function for connecting to the network N, and includes an interface 33. Note that the number and types of the interfaces 33 included in the transmission / reception unit 32 are not limited. When the interface 33 receives a packet addressed to the data transmission side communication device 20 from the communication control unit 34, the interface 33 transmits the packet to the network N. Further, each interface 33, when receiving a packet addressed to the data receiving side communication device 30 from the network N, delivers the packet to the communication control unit 34.

  The communication control unit 34 has a function of performing control related to packet transmission / reception in the data receiving side communication device 30. When the packet received by the interface 33 is a transmission packet from the data transmission side communication device 20, the communication control unit 34 extracts data from the transmission packet and processes the upper layer (not shown) ( For example, processing such as delivery to an application or the like is performed. In addition, when the communication control unit 34 receives a transmission packet from the data transmission side communication device 20, the communication control unit 34 feeds back information related to the reception state. Details of the above-described feedback processing by the communication control unit 34 will be described later.

  Next, an outline of multilink communication between the data transmission side communication device 20 (communication control unit 24) and the data reception side communication device 30 (communication control unit 34) will be described.

  The data transmission side communication device 20 (communication control unit 24) transmits a transmission packet to each route in a state where communication with the data reception side communication device 30 is established in the routes 1 to 3 (a state where multilink communication is established). When sending, a serial number (sequence number) is assigned to the transmission packet. The position at which the serial number assigned to the transmission packet is inserted is not limited. For example, it may be inserted at a predetermined position in the header portion (for example, sequence number) or data portion of the transmission packet (IP packet). good. In the communication system 10, the configuration below the network layer in which the data transmission side communication device 20 uses a plurality of paths to transmit the transmission packet to the data reception side communication device 30 is not limited. 1 may be used.

  Then, when a transmission packet with a serial number arrives, the data reception side communication device 30 (communication control unit 34) feeds back the serial number information to the data transmission side communication device 20 (communication control unit 24). Then, the data receiving side communication device 30 (communication control unit 34) uses the serial number as a clue to grasp the order of transmission packets arriving via a plurality of routes and rearrange the data, and the data transmitted by the plurality of transmission packets Reconfigure.

  In the data receiving side communication device 30 (communication control unit 34), when a transmission packet with a serial number arrives, a packet (hereinafter referred to as "response packet") that feedback (response / report) that the transmission packet with the serial number has arrived. Is transmitted to the data transmission side communication device 20 (communication control unit 24). The format of the response packet transmitted by the data reception side communication device 30 (communication control unit 34) is not limited. For example, information on the serial number of the arrived packet is inserted into the data portion of the response packet (IP packet). You may make it do. Further, as a method for determining whether or not the received packet is a response packet in the data transmission side communication device 20 (communication control unit 24), for example, in the type value field constituting the header portion of the response packet. The identification may be made by applying a specific value.

  Then, the data transmission side communication device 20 (communication control unit 24) updates the contents of the route management table 25 based on the transmission status of the transmission packet and the reception status of the response packet. Based on this, the transfer rate of each route is determined. Specifically, the data transmission side communication device 20 (communication control unit 24) can know the difference in transmission delay time for each path from the packet information fed back. Then, the data transmission side communication device 20 (communication control unit 24) obtains a difference between the timing at which the transmission packet with the serial number assigned to each path is transmitted and the timing at which the response packet for each transmission packet is received. Based on the difference, the ratio of transmission packets to be transmitted is changed. Thereby, in the data transmission side communication apparatus 20 (communication control part 24), the zone | band of each path | route can be utilized effectively.

  As a specific method for the data transmission side communication device 20 (communication control unit 24) to change the transfer rate according to the transmission delay time, the path on which the value having the largest serial number can be detected first has the smallest delay. Since it can be estimated as a route, a procedure for optimizing and maximizing the transmission amount of each packet route by changing (decreasing) the number of packets sent on other routes based on the packet transmission speed of this route is proposed. I can do it.

  Next, an example of the contents of the route management table 25 will be described.

  FIG. 2 is an explanatory diagram showing an example of the contents of the route management table 25.

  In the route management table 25, as shown in FIG. 2, the latest send packet number Qn, the latest arrival packet number Ln, the latest send packet reception flag Rn, and the delay counter Pn (n are all route numbers) for each of the routes 1-3. Parameter information is stored. Each parameter in the route management table 25 shown in FIG. 2 is an initial value of the parameter. In the following, the number of multilinks (number of paths) supported by the data transmission side communication device 20 is represented as m. And as above-mentioned, since the data transmission side communication apparatus 20 respond | corresponds to the three paths 1-3, it becomes m = 3. In the following, n and k represent route numbers.

  The latest transmission packet number Qn indicates a serial number of a transmission packet (hereinafter referred to as “the latest transmission packet”) that is transmitted most recently on the route.

  The latest arrival packet number Ln indicates the serial number of the response packet that has arrived the latest on the route. Here, it is assumed that the initial value of the latest arrival packet number Ln is “0”.

  The latest transmission packet reception flag Rn indicates whether or not a response packet related to the latest transmission packet of the route has been received. The latest transmission packet reception flag Rn is expressed as either valid or invalid, and the initial value is invalid.

  The priority route k indicates the route number of the route (priority route) that is currently assigned the transfer rate with the highest priority. Here, it is assumed that the initial value of the priority route k is “1”.

  The delay counter Pn is a counter indicating how much the transmission status of the transmission packet of the route is delayed compared to the priority route. Details of the delay counter Pn will be described later. It is assumed that the initial value of the delay counter Pn is “0”.

(A-2) Operation | movement of embodiment Next, operation | movement of the data transmission side communication apparatus 20 and the data reception side communication apparatus 30 in the communication system 10 of this embodiment which has the above structures is demonstrated.

  First, processing of the communication control unit 24 in the data transmission side communication device 20 will be described using the flowcharts of FIGS.

  Here, transmission data (for example, a large-capacity file) to be transmitted to the data reception side communication device 30 by the data transmission side communication device 20 (communication control unit 24) is assumed as a premise of the processing according to the flowcharts of FIGS. Etc.). Then, a multilink communication session using paths 1 to 3 is started between the data transmission side communication device 20 (communication control unit 24) and the data reception side communication device 30 (communication control unit 34). And Then, the data transmission side communication device 20 (communication control unit 24) divides the data to be transmitted into units that can be inserted into the transmission packet, and starts processing to transmit to the data reception side communication device 30 by multilink communication. Shall be. As a process of dividing the data to be transmitted and generating a transmission packet, for example, a process similar to the case of transmitting data using TCP / IP with an existing communication device can be applied.

  3 and 4 are flowcharts showing processing when the communication control unit 24 transmits a transmission packet in which the divided data is inserted to the data receiving side communication device 30. FIG.

  FIG. 5 shows processing when the communication control unit 24 receives a response packet of the packet transmitted in the processing of FIGS. 3 and 4. Here, first, referring to FIG. 5, the data transmission side communication device 20 (communication control unit 24) receives a response packet for a transmission packet transmitted through a route of route number x (hereinafter referred to as “route x”). The processing in the case of having been performed will be described.

  First, it is assumed that the communication control unit 24 has received a response packet for a transmission packet transmitted through the path x from the data receiving side communication device 30. Then, the communication control unit 24 updates the latest arrival packet number Lx of the route x to the serial number of the response packet received most recently on the route management table 25 (S201). If the serial number of the response packet received most recently is a number prior to the current Lx, the communication control unit 24 may omit updating Lx.

  Then, the communication control unit 24 confirms the serial number of the received response packet, and confirms from the path management table 25 whether or not the packet serial number corresponds to the latest transmission packet in the path x (S202). When the value of the latest transmission packet number Qx of the path x matches the serial number of the response packet, the communication control unit 24 can confirm that the serial number of the response packet corresponds to the latest transmission packet Qx of the path x. If it is confirmed that the serial number of the response packet corresponds to the latest transmission packet in the route x, the communication control unit 24 sets the latest transmission packet reception flag Rx of the route x on the route management table 25 as “ It is updated to “valid” (S203), and the processing of the response packet is terminated. On the other hand, when the serial number of the response packet does not correspond to the latest transmission packet Qx in the path x, the communication control unit 24 ends the processing of the response packet without updating Rx.

  Next, processing when the communication control unit 24 transmits a transmission packet to the data reception side communication device 30 by multilink communication will be described with reference to FIGS. 3 and 4.

  First, it is assumed that the communication control unit 24 has initialized the parameters of the route management table 25 (S101). Here, it is assumed that the contents of FIG. 2 are obtained as a result of initializing each parameter of the route management table 25.

  Then, the communication control unit 24 selects one of the routes (S102), and starts a repetitive process (hereinafter referred to as “sequential process”) in steps S103 to S108 described later. In the communication control unit 24, sequential processing is performed for all routes in the order selected in step S102 described above. When sequential processing is completed for all routes, sequential processing is performed (steps S110 to S110 described later). S112) is performed, and the sequential processing of one phase is completed. Then, the communication control unit 24 starts processing of a new phase from step S102, and repeatedly performs processing of the same phase (processing of steps S102 to S108) until transmission of all the divided data constituting the data to be transmitted is completed. ) Is performed.

  Step S102 is a process of selecting the order of sequential processing in one phase. Here, the priority route k is selected first, and the subsequent routes are selected in ascending order of route numbers. . That is, in the initial state, as described above, since the priority route k is the route 1, the route 1, the route 2, and the route 3 are selected in this order. Further, for example, when the priority route is route 2, in step S102, route selection is sequentially performed in the order of route 2, route 1, and route 3. In step S102, the order of selecting routes other than the priority route k is not limited.

  Then, in the communication control unit 24, it is assumed that the processing is sequentially started for the path n (hereinafter referred to as “target path n”) selected as the target of sequential processing in step S102. First, the communication control unit 24 checks whether or not the latest transmission packet reception flag Rn of the target route n is valid (S103). When the latest transmission packet reception flag Rn of the target route n is valid, the communication control unit 24 operates from the process of step S104 described later. On the other hand, when the latest transmission packet reception flag Rn of the target route n is invalid, the communication control unit 24 operates from the process of step S108 described later. In the initial state, as described above, the latest transmission packet reception flag R for all routes is invalid. In addition, when Rn is valid, it indicates that all transmission packets sent on the target route have reached the receiving side.

  In the above-described step S103, when the latest transmission packet reception flag Rn of the target route n being processed in the sequential processing is invalid, the communication control unit 24 further sets the value of the delay counter Pn of the target route n. It is referred and it is confirmed whether or not Pn = 0 (S108). In step S108 described above, when Pn = 0, the communication control unit 24 operates from the processing in step S105 described later. On the other hand, if Pn = 0 is not satisfied in step S108 described above, the communication control unit 24 operates from the process in step S109 described later.

  In the above-described step S103, when the latest transmission packet reception flag Rn of the target route n is valid, the communication control unit 24 changes the reception flag Rn to invalid (S104).

  When step S104 described above is completed or when Pn = 0 in step S108 described above, the communication control unit 24 updates the latest transmission packet number Qn of the target route n to the serial number s. (S105).

  Then, the communication control unit 24 sends a packet with the serial number s to the data receiving side communication device 30 via the target path n, and further increments (+1) the value of the serial number s on the path management table 25 (S106). ).

  And the communication control part 24 decrements (-1) the delay counter P (P1-P3) of all the paths (S107). Note that when the delay counter P is 0, the communication control unit 24 keeps 0 instead of minus.

  Next, when the process of step S107 is completed, or when Pn = 0 is not satisfied in step S108 described above, the communication control unit 24 ends the sequential process for the target route n, and The presence / absence of the next target route is confirmed (S109). When there is no next target route in the phase, that is, when the sequential processing of all routes is completed in the phase, the communication control unit 24 proceeds to the processing in step S110 described later. If there is a next target route in the phase, that is, if there is a route that has not yet been sequentially processed in the phase, the communication control unit 24 returns to the processing in step S102 described above, and Shift to sequential processing of the target route.

  When the sequential processing of all the routes is completed in this phase, the communication control unit 24 can finally compare the latest arrival serial numbers L (L1 to L3) of all the routes and confirm the largest value. The designated route is designated as the priority route k (S110).

  Then, the communication control unit 24 recalculates the delay counters P for all routes other than the priority route k (S111). The communication control unit 24 performs recalculation as a delay counter Pn = Lk−Ln other than the priority route k.

  Then, the communication control unit 24 sets the delay counter Pk of the priority route k to “0” (S112), ends the processing of the current phase, and starts the processing of the next phase. Return to processing and work.

  Next, the overall operation of the communication system 10 when the data transmission side communication device 20 (communication control unit 24) operates according to the flowcharts of FIGS.

  FIG. 6 is a timing chart showing communication between the data transmission side communication device 20 and the data reception side communication device 30.

  In FIG. 6, when route 1 has a transmission rate 1/3 that of route 2 and route 3 has a transmission rate 1/7 that of route 2, a packet having a transmission rate 1.5 times that of route 2 that is the earliest. It shows the behavior of each communication device when the message is transmitted. FIG. 6 shows the timing of transmission packet transmission and response packet arrival based on the passage of time from left to right in the figure.

  In FIG. 6, the serial number of the packet is given in a square frame indicating the transmission or arrival timing of each packet. Further, the upper packet string in FIG. 6A shows the transmission timing of the transmission packet transmitted by the data transmission side communication device 20. Further, the lower packet string in FIG. 6A shows the timing at which the response packet from the data reception side communication device 30 reaches the data transmission side communication device 20. Furthermore, the packet sequences shown in FIGS. 6B to 6D show the transmission packets and response packets of the routes 1 to 3, respectively. In each of FIGS. 6B to 6D, the upper packet sequence indicates the transmission timing of the transmission packet of the route, and the lower packet sequence indicates the arrival timing of the response packet of the route. Shows about. That is, the packet sequence shown in FIG. 6A has a content in which the packet sequence of each route shown in FIGS. 6B to 6D is represented by one packet sequence.

  In the upper packet row of FIG. 6A, the inverted triangle mark shown above the packet row is the processing of each phase in the data transmission side communication device 20 (communication control unit 24) (see FIGS. 3 and 4 described above). The end and start timings of the sequential processing shown in FIG. Further, in the upper packet row in FIG. 6A, a triangular mark attached to the lower side of the packet row indicates the timing when the priority route k is switched. Further, hereinafter, a transmission packet with serial number n transmitted by the data transmission side communication device 20 is represented as a transmission packet DSn, and a response packet with serial number n received by the data transmission side communication device 20 is represented as a response packet DRn.

  FIG. 7 shows the contents of the route management table 25 at each timing in the timing chart of FIG. As shown in FIG. 7, the contents of the route management table 25 are the initial contents (at timing T0, the same contents as in FIG. 2).

  In the communication control unit 24, since the transmission speed of each route is initially unknown, the processing is started with the route 1 as the priority route k as shown in FIG. At this time, in the communication control unit 24, the operations of the route 2 and the route 3 are sequentially processed with the setting of no delay difference with respect to the route 1 (that is, all of P1 to P3 are 0). As a result, in the communication control unit 24, the same number of packets as the route 1 that is the priority route are transmitted for the route 2 and the route 3. That is, in the initial phase, a process (equalization process) is performed in which the packet transfer ratios of the route 1 to the route 3 are equally divided. Therefore, as shown in FIGS. 6 and 7, in the phase starting from the initial timing T0, the transmission packets DS1 to DS3 are transmitted to the paths 1 to 3, respectively. In the phase starting from the next timing T1, the transmission packets DS4 to DS6 are transmitted to the paths 1 to 3, respectively.

  As shown in FIG. 6, the communication control unit 24 receives the response packet DS2 related to the route 2 by the timing T2 when the phase starting from the timing T1 ends. Therefore, at the timing T2 when the phase starting from the timing T1 ends, the priority route k becomes the route 2 (the processing in the above-described step S110), and the update processing of the delay counter P of each route (the processing in the above-described steps S111 and S112) is performed. Done. As a result, as shown in FIG. 7, P1 = 2, P2 = 0, and P2 = 2.

  Next, a new phase is started from the timing T2. At this time, since the delay counters of the route 1 and the route 2 are not 0, the packet is transmitted only by the route 2 which is the priority route (the transmission packet DS7). Transmission, the process of step S106 described above).

  Then, until the phase starting from the timing T2 ends (until the timing T3), the response packet DS1 related to the path 1 arrives in the communication control unit 24. Therefore, in the update process of the delay counter P of each path when the phase starting from the timing T2 ends (the process of steps S111 and S112 described above), the delay counter P1 of the path 1 is 1 (P1 = L2-L1 = 2−2). 1 = 1).

  Next, in the communication control unit 24, a phase from timing T3 is started, and packet transmission (transmission of the transmission packet DS8, processing of the above-described step S106) is performed by sequential processing of the route 2 which is the priority route first. The delay counter P1 of path 1 and the delay counter P3 of path 3 are decremented by -1. As a result, since P1 = 0 at the timing T4, transmission packet transmission (transmission of the transmission packet DS9, processing in step S106 described above) is also performed in the sequential processing of the path 1, and further, the delay counter of the path 3 P3 is decremented by 1. As a result, since P3 = 0 at the timing T5, transmission packet transmission (transmission of the transmission packet DS10, the above-described processing of step S106) is also performed in the sequential processing of the path 3, and at the timing T6, The phase process starting from the timing T3 ends.

  The response packets DR5, DR7, DR8 related to the path 2 reach the communication control unit 24 until the timing T6 when the phase starting from the timing T3 ends. Therefore, P1 = 7, P2 = 0, and P3 = 8 in the update processing of the delay counter P of each path when the phase starting from the timing T3 ends (the processing in steps S111 and S112 described above).

  Then, between the timing T6 and the timing T7, as shown in FIG. 6, the response packets related to the route 2 that is the priority route reach the communication control unit 24 one after another. On the other hand, the response packets related to the route 1 and the route 3 are only the response packets DR4, DR3, DR13, and the difference of the delay counter is not 0 as compared with the route 2, so that the packet of only the priority route (route 2) Sending is performed. Then, as shown in FIG. 6, it is assumed that seven transmission packets DS11 to DS17 are transmitted on the path 2 between the timing T6 and the timing T7.

  Then, until the timing T7, the communication control unit 24 reaches the response packet DR13 related to the path 1. At this time, since the latest arrival packet number L1 coincides with the latest transmission packet number Q1, the latest transmission packet reception flag R1 of the path 1 becomes “valid” (the processing in step S204 described above).

  In the phase starting from the timing T7, first, the communication control unit 24 performs packet transmission (transmission of the transmission packet DS18, processing of the above-described step S106) by sequential processing of the route 2 that is the priority route. Next, in the communication control unit 24, the sequential processing of the path 1 is performed. At this time, as described above, the latest transmission packet reception flag R1 of the path 1 is “valid”. As a result of the determination in S103, packet transmission (transmission of the transmission packet DS19, the processing in step 106 described above) is performed regardless of the value of the delay counter P1. At this time, the latest transmission packet reception flag R1 of the path 1 is updated to “invalid” (the process in step S104 described above). Next, in the communication control unit 24, the sequential processing of the path 3 is performed, but the latest transmission packet reception flag R3 = invalid and the value of the delay counter P3 does not become 0, so the packet transmission is not performed. This process ends at the timing T8.

  Then, between timing T8 and timing T9, as shown in FIG. 6, the response packets related to the route 2 that is the priority route reach the communication control unit 24 one after another. On the other hand, since there are few response packets related to the route 1 and the route 3 and the difference between the delay counters is not zero, only the route 2 which is the priority route is transmitted. Then, as shown in FIG. 6, it is assumed that six transmission packets DS20 to DS25 are transmitted on the path 2 between the timing T8 and the timing T9.

  As shown in FIG. 6, the response packet DR19 related to the path 1 arrives at the communication control unit 24 between the timing T8 and the timing T9. Therefore, in the phase that ends at the timing T9, the communication control unit 24 sets the latest arrival packet number L1 related to the route 1 to be larger than L2, and at this time, the priority route k becomes the route 1 (the processing in step S110 described above). Then, the update processing of the delay counter P of each path (the above-described steps S111 and S112) is performed. As a result, as shown in FIG. 7, P1 = 0, P2 = 1, and P2 = 13.

  Next, when a new phase is started from the timing T9, the communication control unit 24 first performs sequential processing of the route 1 which is a priority route, and transmits a transmission packet (transmission of the transmission packet DS26, the above-described steps. S106), and the delay counters P2 and P3 of the paths 2 and 3 are decremented by 1, so that P2 = 0 and P3 = 13. Next, in the communication control unit 24, sequential processing of the path 2 is started. As described above, since the delay counter P1 of the path 2 is 0 at this time, the communication control unit 24 transmits the transmission packet by the sequential processing of the path 2 (transmission of the transmission packet DS27, the processing of the above-described step S106). Is done. Then, in the communication control unit 24, the sequential processing of the path 3 is performed. However, since the delay counter P3 of the path 3 does not become 0 at this time, the transmission packet is not transmitted.

  As shown in FIG. 6, the response packet DR20 related to the path 2 arrives at the communication control unit 24 between the timing T9 and the timing T10. Therefore, in the phase starting from timing T9, in the communication control unit 24, the latest arrival packet number L2 related to the route 2 becomes larger than L1, and at this time, the priority route k becomes the route 2 (the processing in step S110 described above). Update processing of the delay counter P for each path (the processing in steps S111 and S112 described above) is performed. As a result, as shown in FIG. 7, P1 = 1, P2 = 0, and P2 = 17.

  As described above, in the data transmission side communication device 20 (communication control unit 24), the processing shown in the flowcharts of FIGS. 3 to 5 is repeatedly performed. Further, as shown in FIG. 6, the data transmission side communication device 20 (communication control unit 24) receives the response packets DR1 to 20 at timing T10. In the control unit 34), at least the transmission packets DS1 to DS20 have arrived. Therefore, at the timing 10, the data receiving side communication device 30 (communication control unit 34) can rearrange at least the data of the transmission packets DS1 to DS20.

  As described above, in the data transmission side communication device 20 (communication control unit 24), the route with the largest latest arrival packet number L (the route with the latest serial number) is transmitted at the present time (the transmission packet is transmitted). And the time from when the response packet is received is estimated to be the shortest route), and the route is designated as the priority route k. The communication control unit 24 preferentially assigns transmission packets to the current priority route k.

  Further, in the communication control unit 24, a delay counter P is provided as a measure for how much the transmission delay is longer than the priority route k for routes other than the priority route k, and the delay counter P is 0. At this stage, packet transmission is performed along the route.

  Further, in the communication control unit 24, for all routes other than the priority route k, even when the delay counter P does not become 0, all response packets for the transmission packets that have already been transmitted are received (that is, the latest transmission packet number). In the case of Q = latest transmission packet reception flag R), the latest transmission packet reception flag R is set to “valid” and packet transmission is performed on the route.

  As described above, the communication control unit 24 assigns the number of packets corresponding to the delay amount of each path. As a result, in a state where continuous packet transfer is performed over a long period of time, transmission is performed with the smallest amount of delay while effectively utilizing the bandwidth.

(A-3) Effects of Embodiment According to this embodiment, the following effects can be achieved.

  The data transmission side communication device 20 updates the contents of the route management table 25 according to the reception status of the response packet from the data reception side communication device 30, and determines the priority route k based on the contents of the route management table 25. ing. Then, the data transmission side communication device 20 preferentially supplies the transmission packet to the priority route k, and for other routes, when all the transmission packets reach the reception side, or when the delay amount (delay counter) is small A transmission packet is allocated to the network. That is, the data transmission side communication device 20 assigns the number of transmission packets corresponding to the small amount of delay of each route for routes other than the priority route k, and transmits the transmission packet with the maximum capacity that can be efficiently transmitted. Can be sent. The feature of packet transmission by this method is that the operation is matched to the delay amount of the route with the fastest transmission speed, so the route with the fastest transmission rate is preferentially used, and the route with the slow transmission rate and the large delay is sufficient. As long as you are doing it, it will automatically become an operation that is hardly used.

  Further, in this embodiment, the data transmission side communication device 20 and the data reception side communication device 30 are efficient with only a simple procedure and without specifying transmission performance or transmission content in advance. Multilink communication is realized.

(B) Other Embodiments The present invention is not limited to the above-described embodiments, and may include modified embodiments as exemplified below.

(B-1) In the above embodiment, an example in which a response packet is used as a method of feeding back the serial number of a received transmission packet from the data receiving communication device 30 to the data transmitting communication device 20 has been described. The method itself is not limited. However, the feedback from the data reception side communication device 30 is preferably as soon as the information update of the timing and order received on each path at the time of transmission packet reception and the notification to the transmission side is faster.

(B-2) In the above embodiment, the packet (frame) flowing between the data receiving communication device 30 and the data receiving communication device 30 is described as being in the IP packet format, but the packet format is It is not limited.

(B-3) In the above-described embodiment, the description of the procedure abnormality countermeasure and the retransmission process when the transmission packet to be transmitted from the data transmission side communication device 20 to the data reception side communication device 30 has not arrived is omitted. However, there is no limitation on the procedure abnormality countermeasure and the retransmission processing method. For example, since the data reception side communication device 30 can detect the loss of the transmission packet based on the serial number of the received transmission packet, only the missing transmission packet is notified to the data transmission side communication device 20 or a retransmission request is made. Anyway.

(B-4) In the above embodiment, the communication control unit 24 of the data transmission side communication device 20 divides the transmission target data supplied from the upper layer, inserts the divided data into the transmission packet, and transmits it. However, data supplied from an upper layer (data having a length that can be inserted into a transmission packet) may be inserted into a transmission packet (with a serial number) and transmitted.

  1, 2, 3,..., 10, communication system, 20, data transmission side communication device, 21, control unit, 22, transmission / reception unit, 23, 23-1 to 23-3, interface, 24, communication control unit, 25 ... path management table, 30 ... data receiving side communication device, 31 ... control unit, 32 ... transmission / reception unit, 33 ... interface, 34 ... communication control unit, N ... network.

Claims (7)

In a communication system comprising a data reception side communication device and a data transmission side communication device that transmits a plurality of transmission packets in which data is inserted to a data reception side communication device by communication in which a plurality of paths are bundled.
The data transmission side communication device is:
Transmission packet holding means for holding a plurality of transmission packets each assigned serial number information;
Transmission packet transmission means for transmitting the transmission packets held by the transmission packet holding means to the data receiving communication device using any of the routes in the order of serial numbers;
A notification receiving means for receiving from the data receiving communication device, an arrival notification including information on the serial number of the transmission packet that has reached the data receiving communication device;
In accordance with the arrival status of the arrival notification for each route, the transmission rate for the transmission packet to be sent to each of the routes is determined, and the transmission packet is sent to each of the routes at the determined transmission rate. Transmission packet transmission control means for controlling the transmission packet transmission means,
The data receiving side communication device is:
A transmission packet receiving means for receiving a transmission packet transmitted from the data transmission side communication device;
A communication system comprising: notification transmission means for extracting serial number information from the transmission packet received by the transmission packet reception means and transmitting an arrival notification including the serial number information to the data transmission side communication device. .   The transmission packet transmission control means assigns the largest transmission rate to the route that can be estimated to have the smallest delay from the transmission packet being transmitted until the response notification corresponding to the transmission packet is received. The communication system according to claim 1.   The transmission packet transmission control unit estimates the route having the serial number of the currently received response notification as the last number as the route with the shortest delay. Communications system. In a data transmission side communication device that transmits a plurality of transmission packets into which data is inserted to a data reception side communication device by communication in which a plurality of paths are bundled,
Transmission packet holding means for holding a plurality of transmission packets each assigned serial number information;
Transmission packet transmission means for transmitting the transmission packets held by the transmission packet holding means to the data receiving communication device using any of the routes in the order of serial numbers;
A notification receiving means for receiving from the data receiving communication device, an arrival notification including information on the serial number of the transmission packet that has reached the data receiving communication device;
In accordance with the arrival status of the arrival notification for each route, the transmission rate for the transmission packet to be sent to each of the routes is determined, and the transmission packet is sent to each of the routes at the determined transmission rate. And a transmission packet transmission control means for controlling the transmission packet transmission means. In a data reception side communication device that receives a transmission packet from a data transmission side communication device that transmits a plurality of transmission packets in which data is inserted by communication in which a plurality of paths are bundled,
A transmission packet receiving means for receiving a transmission packet including serial number information sent from the data transmission side communication device;
A data transmission device comprising: a notification transmission unit configured to extract serial number information from the transmission packet received by the transmission packet reception unit and to transmit an arrival notification including the serial number information to the data transmission side communication device. Side communication device. A computer mounted on a data transmission side communication device that transmits a plurality of transmission packets into which data is inserted to a data reception side communication device by communication in which a plurality of paths are bundled.
Transmission packet holding means for holding a plurality of transmission packets each assigned serial number information;
Transmission packet holding means for holding a plurality of transmission packets each assigned serial number information;
Transmission packet transmission means for transmitting the transmission packets held by the transmission packet holding means to the data receiving communication device using any of the routes in the order of serial numbers;
A notification receiving means for receiving from the data receiving communication device, an arrival notification including information on the serial number of the transmission packet that has reached the data receiving communication device;
In accordance with the arrival status of the arrival notification for each route, the transmission rate for the transmission packet to be sent to each of the routes is determined, and the transmission packet is sent to each of the routes at the determined transmission rate. A data transmission side communication program which functions as transmission packet transmission control means for controlling transmission packet transmission means. A computer mounted on a data reception side communication device that receives a transmission packet from a data transmission side communication device that transmits a plurality of transmission packets into which data is inserted by communication in which a plurality of paths are bundled.
A transmission packet receiving means for receiving a transmission packet including serial number information sent from the data transmission side communication device;
A serial number information is extracted from the transmission packet received by the transmission packet reception unit, and the data transmission side communication device is made to function as a notification transmission unit that transmits an arrival notification including the serial number information. Data receiver communication program.

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