JP2002217963A - Data distribution managing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable faster and more efficient data distribution by adjusting the timing or quantity of transmission for a virtual delivery confirmation response, while considering the states of a transmission/reception buffer, window size, line congestion, etc. SOLUTION: A data distribution managing system 10 comprises a distribution managing table 1, in which the information of window size for a terminal device C1 is held, and an SG distribution managing part 16 which controls not to allow return process for a virtual delivery confirmation response, based on the window size held in the distribution managing table 1, and the system generates a virtual delivery confirmation response according to the window size or an originator, and decides whether to return it, or otherwise adjusts the transmission timing of the virtual delivery confirmation response.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for communicating between a first terminal device which performs a communication requiring a delivery confirmation response to transmitted data and a second terminal device which is a communication partner of the first terminal device. The transmission delay between the first terminal device and the first terminal device is smaller than the transmission delay between the first terminal device and the first terminal device. The present invention relates to a data delivery management device capable of performing a transfer process for transferring to the second terminal device and a return process for creating and returning a delivery acknowledgment for the transferred data. The present invention relates to a data distribution management device capable of improving speed performance degradation depending on reception timing.

[0002]

2. Description of the Related Art Conventionally, in communication using TCP, a TCP on the transmitting side has a window size corresponding to a transmission buffer, and data is transmitted one after another by sliding a transmission window within this window size. I do. If a situation occurs in which the delivery acknowledgment is not accepted for some reason, the TCP determines that it is in a congestion state, reduces the window size, thereby lowering the throughput and trying to eliminate the congestion.

[0003] However, in a line having a large capacity such as a satellite line and a physically large transmission delay, TCP is used.
Is used, depending on the physical distance, it may take 0.5 seconds or more from the data transmission until the delivery confirmation response for the data is returned. This 0.5 second is a retransmission timeout time in general TCP, that is, a time until data transmission is determined to be failed and data retransmission is started, and TCP determines that a congestion state has occurred. Time. As a result, there arises a problem that the speed performance, that is, the throughput, cannot be exhibited corresponding to the original size of a large capacity line like a satellite line.

FIG. 11 is a block diagram showing a configuration of a data distribution management system using a conventional data distribution management device (see IPSJ Research Report 98-DPS-89-12). This data distribution management system solves the above-mentioned problems,
This is a system that can improve throughput. In FIG. 11, the data distribution management system includes:
The transmitting device C11, the receiving device C12, and the transmitting device C
11 and a transmission gateway 100 connected to the receiving device C12 via lines L11 and L12 for performing TCP communication. Line L12 is line L11
This is a line having a longer transmission delay than that of a line, for example, a satellite line.

In FIG. 11, a transmitting device C11 includes a data packet output unit 111 for outputting a data packet,
A temporary delivery acknowledgment receiving unit 112 for receiving the temporary arrival acknowledgment created by the transmission gateway 100. The transmission gateway 100 has a buffer 101 and a distribution management table 102, receives a data packet transmitted from the transmission device C11, stores the data packet in the buffer 101, and a buffer 101 via the line L12. An output unit 104 for outputting the data packet stored in the receiving device C12 to the receiving device C12;
Temporary delivery acknowledgment creating unit 105 that creates a temporary delivery acknowledgment for the data packet transmitted to receiving device C12
A temporary delivery confirmation response transmitting unit 106 for transmitting the created temporary delivery confirmation response to the transmitting device C11, and a receiving device C1
2 and a delivery information storage control unit that obtains communication information from the received SYN (connection request) packet and records it as delivery information in the delivery management table 102. 108 and a retransmission processing unit 109 for performing a retransmission process of the data packet. The receiving device C12 is connected to the transmitting gateway 100.
And a delivery acknowledgment output unit 122 that outputs a delivery acknowledgment to the transmission gateway 100.

When a data packet is transmitted from the transmitting device C11, the transmitting gateway 100 temporarily stores the received data packet in the buffer 101 and adds an entry of the data packet to the distribution management table 102. The transmission gateway 100 transmits the data packet received from the transmission device C11 to the line L12.
And a data packet of a provisional arrival acknowledgment for the data packet is created, and the provisional arrival acknowledgment is transmitted to the transmission device C11.

The receiving device C12 is connected to the transmitting gateway 10
When a data packet is received from 0, a delivery acknowledgment for the received data packet is created, and the delivery acknowledgment is transmitted to the transmission gateway 100. This delivery confirmation response includes data relating to the corresponding data packet and data relating to the state of arrival confirmation of the data packet. The transmission gateway 100 that has received the delivery confirmation response from the receiving device C12 clears the data packet held in the transmission gateway 100 and corresponding to the delivery confirmation response.

Here, in the process of transmitting a data packet from the transmitting gateway 100 to the receiving device C12, the transfer of the data packet fails and the receiving device C1
2 cannot receive this data packet, the transmission gateway 100 receives three identical delivery acknowledgments from the receiving device C12 side in succession, and performs retransmission processing of this data packet.

As described above, in the conventional data distribution management system, the transmission gateway 100 transmits a data packet from the transmission gateway 100 to the receiving device C12, and at the same time, transmits a temporary delivery acknowledgment (tmpACK) to the transmitting device C11. By returning, line L12
This has prevented the reduction of the TCP window size due to the transmission fee, and the degradation of the speed performance has been improved without the decrease in the throughput.

[0010] When receiving the data packet from the transmitting device, transmitting gateway 100 creates a provisional delivery acknowledgment and holds the data packet until it receives a delivery acknowledgment (ACK) from the receiving device. When two identical delivery acknowledgments (DuplicateACK) are received, the transmission of this data packet is determined to be unsuccessful, and the held data packet is retransmitted.

[0011]

However, in the conventional data distribution management system, when a data segment is received from the transmitting device C11, the transmitting gateway 100
However, without considering the state of the transmission / reception buffer or window of the transmission device C11 and the congestion state of the line L11, a temporary acknowledgment for all data segments is immediately created and transmitted to the transmission device C11. Therefore, there is a problem that the processing load on the transmission gateway 100 and the transmission device C11 increases, and as a result, speed performance may deteriorate.

The data including the delivery acknowledgment transmitted from the receiving device C12 is transmitted at the throughput determined by the receiving device C12 according to the state of the receiving window of the transmitting device C11. When the data is received by the gateway 100, the data has been transferred at the throughput based on the previous old window size. Therefore, if the reception buffer or the reception window of the transmission device C11 is reduced, the transmission device C
However, there is a problem that the state of the updated reception buffer or the reception window of the transmission device C11 cannot be dealt with and the reception buffer and the window of the transmission device C11 may overflow.

The present invention has been made in view of the above, and takes into account the state of a transmission / reception buffer, a window size, line congestion, and the like, and adjusts the transmission timing or transmission amount of a provisional acknowledgment to achieve higher speed and higher transmission speed. It is an object of the present invention to obtain a data distribution management device capable of efficiently performing data distribution.

[0014]

In order to achieve the above object, a data distribution management device according to the present invention comprises a first terminal device for performing communication requiring a delivery acknowledgment for transmitted data and the first terminal device. The terminal device is arranged on a transmission path between the terminal device and a second terminal device with which the terminal device communicates, and a transmission delay between the terminal device and the first terminal device is smaller than a transmission delay between the terminal device and the second terminal device. And a transfer process of transferring at least data from the first terminal device to the second terminal device and a return process of creating and returning a delivery confirmation response to the transferred data can be performed. In the data distribution management device, holding means for holding information on the window size of the first terminal device, and returning processing of the delivery confirmation response based on the information on the window size held by the holding means. Determining means for determining whether, wherein said determining means and a control means for performing a return process of the delivery acknowledgment when it is determined to perform the return processing of the delivery acknowledgment.

According to the present invention, the holding means comprises the first
Holding the window size information of the terminal device, the determining means determines whether to perform the return processing of the delivery acknowledgment based on the window size information held by the holding means, control means, The acknowledgment is returned only when the determination means determines that the acknowledgment is to be returned, and the transmission timing or the transmission amount of the acknowledgment to the transmission source is adjusted. .

[0016] A data distribution management device according to the next invention comprises a first terminal device for performing communication requiring a delivery acknowledgment for transmitted data and a second terminal which is a communication partner of the first terminal device. A transmission delay between the first terminal device and the first terminal device, wherein a transmission delay between the first terminal device and the second terminal device is smaller than a transmission delay between the first terminal device and the first terminal device. A data transfer management device capable of performing a transfer process of transferring the data of the first terminal device to the second terminal device and a return process of generating and returning an acknowledgment response to the transferred data. Holding means for holding the information on the window size of the first terminal device, and transmitting the data transmitted by the first terminal device in accordance with the window size indicated by the information on the window size held by the holding means. Characterized in that a control means for controlling for varying the return timing of the acknowledgment.

According to the present invention, the holding means comprises the first
Control means for returning the acknowledgment response to the data transmitted by the first terminal device in accordance with the window size indicated by the window size information held by the holding means. Control to vary the timing is performed.

[0018] The data distribution management device according to the next invention is the data transmission management device according to the above invention, wherein a transmission acknowledgment is returned from the reception acknowledgment received from the second terminal to the first terminal. A predetermined value obtained by subtracting the previous window size from the current window size of the first terminal device from a current delay time having a predetermined lower limit value substantially corresponding to the delay time up to Calculating a maximum value between a second subtraction value obtained by subtracting a second value obtained by multiplying the second and the predetermined lower limit value, calculating a minimum value between the maximum value and a predetermined upper limit value, and calculating the minimum value Calculating means for calculating the latest current delay time by repeating the process of resetting the current delay time as the current delay time, the control means according to the latest current delay time calculated by the calculating means Previous First terminal device and performing a control for varying the return timing of the delivery acknowledgment to the transmitted data.

According to the present invention, the calculating means comprises the second
From the current delay time with a predetermined lower limit substantially corresponding to the delay time from the time of receipt of the acknowledgment response received from the terminal device to the time of return of the acknowledgment response to the first terminal device as the initial value. A second subtraction value obtained by subtracting a second value obtained by multiplying a first subtraction value obtained by subtracting a previous window size from a current window size in the first terminal device by a predetermined value, and the predetermined lower limit value Calculate the maximum value of, calculate the minimum value of the maximum value and the predetermined upper limit value, calculate the latest current delay time by repeating the process of resetting the minimum value as the current delay time The control means controls the return timing of the acknowledgment response to the data transmitted by the first terminal device in accordance with the latest current delay time calculated by the calculation means. There.

[0020] A data distribution management device according to the next invention comprises a first terminal device for performing communication requiring a delivery acknowledgment for transmitted data, and a second terminal which is a communication partner of the first terminal device. A transmission delay between the first terminal device and the first terminal device, wherein a transmission delay between the first terminal device and the second terminal device is smaller than a transmission delay between the first terminal device and the first terminal device. A data transfer management device capable of performing a transfer process of transferring the data of the first terminal device to the second terminal device and a return process of generating and returning an acknowledgment response to the transferred data. Holding means for holding at least the window size, the number of segments of data received from the first terminal device, and the presence or absence of a reception confirmation response from the second terminal device;
A determination to determine whether to return the acknowledgment to the data transmitted by the first terminal device based on a combination of the window size, the number of segments, and the presence or absence of the acknowledgment held by the holding unit. Means, and control means for returning the acknowledgment response when the determining means determines to return the acknowledgment response.

According to the present invention, the holding means comprises the first
Holding at least the window size of the terminal device, the number of segments of data received from the first terminal device, and the presence or absence of a reception acknowledgment from the second terminal device. Determine whether to return the delivery acknowledgment to the data transmitted by the first terminal device by a combination of the window size and the number of segments and the presence or absence of the acknowledgment,
The control means returns the acknowledgment response when the determining means determines to return the acknowledgment response.

[0022] A data distribution management device according to the next invention comprises a first terminal device for performing communication requiring a delivery acknowledgment for transmitted data and a second terminal which is a communication partner of the first terminal device. A transmission delay between the first terminal device and the first terminal device, wherein a transmission delay between the first terminal device and the second terminal device is smaller than a transmission delay between the first terminal device and the first terminal device. A data transfer management device capable of performing a transfer process of transferring the data of the first terminal device to the second terminal device and a return process of generating and returning an acknowledgment response to the transferred data. Holding means for holding the information on the window size of the first terminal device, and transmitting the data transmitted by the first terminal device in accordance with the window size indicated by the information on the window size held by the holding means. Characterized by comprising a control means for performing control to vary the creation density acknowledgment.

According to the present invention, the holding means comprises the first
Holding the window size information of the terminal device, and the control unit generates the delivery confirmation response to the data transmitted by the first terminal device according to the window size indicated by the window size information held by the holding unit. The density is varied, for example, control is performed to thin out the delivery confirmation response.

The data distribution management device according to the next invention is the data distribution management device according to the above invention, wherein at least a data buffer for holding the data transmitted by the first terminal device and a registration of at least the data transmitted by the first terminal device are provided. Management means for managing information; and when receiving a delivery confirmation response to the data from the second terminal device to which the data transmitted by the first terminal device has been transferred, the data stored in the data buffer; A deletion control unit for performing control for deleting registration information of the data managed by the management unit.

According to the present invention, the data buffer holds at least the data transmitted by the first terminal device, and the management means manages at least registration information of the data transmitted by the first terminal device, When the deletion control unit receives a delivery confirmation response to the data from the second terminal device to which the data transmitted by the first terminal device has been transferred, the data stored in the data buffer and the management unit Is controlled to delete the registration information of the data managed by.

[0026] The data distribution management device according to the next invention, in the above invention, further comprises a counting means for counting the number of delivery-confirmed segments which are data to be deleted among the data held in the data buffer. Prepared,
The deletion control means transmits registration information to the data managed by the management means each time a delivery confirmation response to the data is received from the second terminal device to which the data transmitted by the first terminal device has been transferred. When the number of segments set to “confirmed delivery” set by the counting means and counted by the counting means exceeds a predetermined number, the delivery-confirmed data held in the data buffer and the management means are The registration information of the data whose delivery has been confirmed to be managed is deleted.

According to the present invention, the counting means counts the number of delivery-confirmed segments which are data to be deleted among the data held in the data buffer, and the deletion control means Each time a delivery confirmation response to the data is received from the second terminal device to which the data transmitted by the terminal device has been transferred, the registration information is set to delivery confirmed in the data managed by the management means, and the counting means When the number of segments set to “delivery confirmed” counted by the counter exceeds a predetermined number, the data of the delivery confirmed data held in the data buffer and the delivery confirmed data managed by the management unit are displayed. The registration information is deleted.

[0028] In the data distribution management device according to the next invention, in the above-mentioned invention, the first counter for counting the number of delivery-confirmed segments, which are data to be deleted, of the data held in the data buffer. Means, and second counting means for counting registration information of data to be deleted among data managed by the management means, wherein the deletion control means converts the data transmitted by the first terminal device. Each time a delivery acknowledgment for the data is received from the transferred second terminal device, the information about the data managed by the management means is set to delivery confirmed, and the first
When the number of segments set as delivery confirmed counted by the counting means exceeds a first predetermined number, the delivery confirmed data held in the data buffer is deleted, and the second counting is performed. When the registration information of the delivery-confirmed data counted by the means exceeds a second predetermined number, the registration information of the delivery-confirmed data is deleted.

According to the present invention, the first counting means counts the number of delivery-confirmed segments which are data to be deleted among the data held in the data buffer, and the second counting means Counting the registration information of the data to be deleted among the data managed by the management means, and the deletion control means transfers the data transmitted by the first terminal device from the second terminal device to which the data has been transmitted. Each time a delivery acknowledgment is received, information on the data managed by the management means is set to delivery confirmed, and the number of segments set to delivery confirmed by the first counting means is equal to a first predetermined number. If the number exceeds the number, the data whose delivery has been confirmed held in the data buffer is deleted, and the registration information of the data whose delivery has been confirmed counted by the second counting means is the second predetermined number. In the case beyond the, so that to remove the registration information of the delivery confirmed the data.

[0030] The data distribution management device according to the next invention is characterized in that, in the above invention, the data distribution management device further comprises a clock unit for clocking a predetermined time, and the deletion control unit transmits the data transmitted by the first terminal device. Each time a delivery confirmation response to the data is received from the second terminal device, the registration information is set to delivery confirmed in the data managed by the management unit, and when the timing unit times the predetermined time, It is characterized in that the delivery confirmed data held in the data buffer and the registration information of the delivery confirmed data managed by the management means are deleted.

According to the present invention, the clocking means further includes clocking means for clocking a predetermined time, and the deletion control means transmits the data transmitted by the first terminal device from the second terminal device to which the data transmitted by the first terminal device has been transferred. Each time a delivery confirmation response to the data is received, the registration information is set to delivery confirmed in the data managed by the management unit, and when the predetermined time has been counted by the timing unit, the data is held in the data buffer. The registered data of the delivery-confirmed data and the registration information of the delivery-confirmed data managed by the management unit are deleted.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a data distribution management device according to the present invention will be described below in detail with reference to the accompanying drawings.

Embodiment 1 FIG. 1 is a block diagram showing a configuration of a data distribution management system including a data distribution management device according to Embodiment 1 of the present invention. In FIG. 1, the data distribution management system includes a terminal device C1 connected to a data distribution management device 10 via a line 2a, a data distribution management device 10 connected to a data distribution management device 20 via a line 3, Delivery management device 20 is line 2
b to the terminal device C2. The line 3 is a line with a large transmission delay such as a satellite line, and the lines 2a and 2
The line b has a smaller transmission delay than the line 3.

The data distribution management device 10 has a gateway function unit 10a, a distribution management table 1, a protocol management table 5, a transmission buffer 6, and a reception buffer 7. The gateway SG is a communication unit 1 that performs input / output processing of data packets with the terminal device C1.
7, a communication unit 11 for input / output processing of a data packet between the terminal device C2 via the data distribution management device 20, and a tmpACK for storing a data packet for creating a temporary delivery acknowledgment (tmpACK). Tm for determining whether to return tmpACK for the data packet transmitted to buffer 4 and terminal device C2
pACK use determination unit 12, tmpA that creates tmpACK based on the data packet received from terminal device C1
A CK creating unit 13; an SGTimer counting unit 14 that counts up a timeout period (SGTimer) of a delivery confirmation response for each data packet and generates a timeout event waiting for the delivery confirmation response;
1, a distribution data recording unit 15 that performs a process of writing information on whether a tmpACK has been transmitted to the terminal 1 and information on a delivery confirmation response from the terminal device C2 into the delivery management table 1.
An SG distribution management unit 16 that manages distribution of data packets in accordance with the SGTimer value and the contents of the distribution management table 1.

In FIG. 1, the transmission buffer 6, the reception buffer 7, and the tmpACK buffer 4 are shown as separate buffers. However, the present invention is not limited to this, and some or all of them are implemented as the same buffer. You may do so. In addition, a management table (not shown) is provided which can be used together with information including control information according to a management purpose, regardless of whether it is implemented as a separate buffer or as the same buffer. By mounting the packet data so that the storage location of the packet data can be identified, the efficiency of management and search can be improved.

The data distribution management device 20 has the same configuration as the data distribution management device 10. Data distribution management device 1
0 transfers the data packet transmitted from the terminal device C1 to the terminal device C2 via the data distribution management device 20. At this time, the data distribution management device 10
The use determining unit 12 determines whether or not to apply the tmpACK return function to the data packet received from the terminal device C1. A data acknowledgment (tmpACK) is returned, and the data delivery management device 20 performs only the routing process of transferring the data packet sent from the data delivery management device 10 to the terminal device C2, similarly to a normal gateway, and transmits the tmpACK. No return processing is performed. Further, the data distribution management device 20
Transfers the data packet transmitted from the terminal device C2 to the terminal device C1 via the data distribution management device 10.
At this time, the data distribution management device 20 determines whether or not the tmpACK use determination unit 12 applies the tmpACK return function to the data packet received from the terminal device C2. C2
The data distribution management device 10 performs only the routing process of transferring the data packet transmitted from the data distribution management device 20 to the terminal device C1, similarly to the normal gateway. , TmpACK is not returned. Thereby, bidirectional communication between the terminal devices C1 and C2 is realized. In the following description, the operation of the data distribution management device 10 will be described with the terminal device C1 as the transmitting terminal and the terminal device C2 as the receiving terminal.
The operation process of the data distribution management device 20 when the terminal device 2 is the transmission terminal and the terminal device C1 is the reception terminal is the same as that of the data distribution management device 10.

Here, a data distribution management process of the data distribution management device 10 will be described with reference to FIGS. First, when receiving the data packet, the communication units 17 and 11 of the gateway SG temporarily store the received data packet in the reception buffer 7 and store the received data packet in the SG distribution management unit 16.
Performs the distribution process shown in FIG.

In FIG. 2, first, the tmpACK use determining unit 12 checks the received data packet, and according to the check result, the data distribution management device 10
Of the tmpACK available flag for the received data packet of the “ON” and “OFF” is determined, and the tmpACK available flag is set to “ON” and “OFF” as necessary.
The information of the received data packet is registered in the distribution management table 1 (step S11).

Thereafter, it is determined whether or not the use control of the tmpACK is performed based on the tmpACK control flag (step S12). If the usage control of tmpACK is not performed (step S12, NO), the present process is terminated as it is, and the usage control of tmpACK is performed (step S1).
(2, YES), tmpACK use control processing is executed (step S13), and this processing ends.

FIG. 3 is a flowchart showing the packet check processing procedure in step S11 shown in FIG. In FIG. 3, first, the data distribution management device 10
Indicates that the IP address of the received data packet is
Using the path management table 1a, it is determined whether or not the destination of the received data packet is the P address and the transmission is via a line with a long delay (step S2).
1). In this step S21, it is checked whether or not the header of the network layer is an IP header, and thereafter, it is determined using the distribution management table 1 whether or not a transmission delay line exists on the route determined by the routing function. I do. When the protocol does not use IP, when the address is not in the correct format, and when there is no transmission delay line on the path to the destination (step S21,
NO), the tmpACK available flag is set to “OFF”
(Step S22), the received data packet is transferred to the destination (Step S23), and the process returns to Step S11. If a management table (not shown) provided in the separate buffer or the same buffer as described above is used, the tmpACK availability flag may be held as information in the management table.

FIG. 4 is a diagram showing the contents of the route management table 1a. In FIG. 4, the route management table 1a manages a route to a destination for each destination IP, and describes whether there is a delay for each route. For example, when the destination IP is “10.74.3.200”, four routes of routes “1” to “4” are listed, but the route of route “1” is a route with a delay. Become. Therefore, when the route “1” is selected, it is determined that the transfer is to the delay-dependent line.

Thereafter, if the IP address of the received data packet is correct and there is a transmission delay in the route to the destination (step S21, YES), the tmpACK use determination unit 12 uses the protocol management table 5
It is determined whether or not the protocol of the IP header is delay-dependent (step S24). If the protocol of the IP header is delay-dependent (step S24, YES), it is further determined whether or not the transmission port of the TCP header is delay-dependent (step S25). If the protocol of the IP header is not delay-dependent (step S24, NO) and if the transmission port of the TCP header is not delay-dependent (step S25, NO), the tmpACK available flag is set to "OFF" (step S22). Then, the received data packet is transferred to the destination (step S2).
3), and return to step S11.

FIG. 5 is a diagram showing an example of a judgment table in the protocol management table 5 used by the tmpACK use judgment unit 12. In FIG. 5, an item D1 of the reference header indicates a header portion used for determining a data packet to be determined. Also, item D2 of the protocol name
Indicates the type item of the protocol of the data in the header part specified by the reference header item D1. Further, the item D3 of whether or not spoofing can be used represents information indicating whether or not the protocol should use the tmpACK return process. The specific determination processing in steps S24 and S25 based on this determination table will be described. First, in step S24, the tmpACK usage determination unit 12 refers to a byte string indicating the protocol of the IP header of the received data packet. If it is determined that the TCP data has been received, in step S25,
Referring to the source port number in the TCP header, if it is determined that the packet is not BGP, it can be determined that the tmpACK return process can be used. On the other hand, when BGP data is received, it can be determined that the tmpACK return process cannot be used.

If it is determined in step S24 that the upper layer protocol in the protocol portion of the IP header is not a delay-dependent protocol in the data distribution management device 10 (step S24, NO), t is set as described above.
The mpACK available flag is set to "OFF" (step S22), the received data packet is transferred to the destination (step S23), and the process returns to step S11. On the other hand, if it is determined in step S24 that the upper layer protocol is a delay-dependent protocol, and if it is determined in step S25 that the upper-layer protocol is not a delay-dependent protocol based on the source port number of the TCP header, as described above, Then, the tmpACK available flag is set to "OFF" (step S22), the received data packet is transferred to the destination (step S23), and the process returns to step S11.

Now, in steps S24 and S25,
If it is determined that the protocol is a delay-dependent protocol, it is determined whether or not the data packet is a data packet at the start of communication by referring to the code bit value in the header of the received data packet (step S26). A dedicated buffer is provided as a starting packet buffer (not shown). Alternatively, buffers such as the reception buffer 7 and the transmission buffer 6 may be used as a starting packet buffer (not shown). A data packet to be stored in a start-time packet buffer (not shown) is defined as one communication in which each transmission device, each reception device, each combination of a transmission device and a reception device to communicate, and a device and a communication port which communicate are the same. In such a case, a tag may be attached and managed for each communication or for each type of communication.

If the data packet is not a data packet at the time of starting communication (step S26, NO), it is determined whether or not the received data packet is a communication already registered in the distribution management table 1 (step S27). This step S
In 27, it is determined that the communication in which the combination of the source IP in the IP header and the source port in the TCP header and the combination of the destination IP and the destination port are all the same management unit and are registered communications I do.

FIG. 6 shows an example of the distribution management table. In FIG. 6, items D11 to D16
Is an item indicating information regarding communication with the same management unit, and items D17 to D19 are items indicating information regarding data packets received by the data distribution management device 10 in communication with the same management unit. Items D11 to D19
Is information obtained from the data packet received by the data distribution management device 10. Item D11 indicates the source IP address of the communication to be managed, and item D12 indicates the destination I
Item D13 indicates a source port number, item D14 indicates a destination port number, and item D1
5 indicates a temporary ACK stop flag, and item D16 indicates the latest transmission window size and reception window size at the transmission source and destination, respectively. An item D17 indicates the sequence number of the data segment received by the data distribution management device 10 in this communication, and an item D18 indicates information related to the transmission of tmpACK. The information of this item D18 includes information on whether or not the data packet is a transmittable data packet, including the case where a condition such as when certain conditions are satisfied for the transmission source, and tm
Information such as whether or not pACK has been transmitted is used as a value. Item D19 represents information on the delivery acknowledgment (RRACK) from the destination. In FIG. 6, "ACK received" indicating that the corresponding data packet has received RACK and the arrival of RACK are shown in FIG. "Waiting for ACK" to indicate that it is waiting for
Has the following two values.

For example, in FIG. 6, a row DD1 includes:
The transmission port `` FTP.D '' of the source terminal device `` 10.74.3.177 ''
In the communication from the ATA to the destination port “1301” of the destination terminal device “10.74.3.200”, the temporary ACK stop flag is “OFF”, the transmission window size and the reception window size of the transmission source, and the transmission window of the destination. The size and the reception window size are all 16 Kbytes, and the data packet having the sequence number “398” is a data packet in which the transmission of tmpACK is “impossible”, that is, the data packet that does not transmit tmpACK in any condition. Yes, indicating that it is currently waiting for a delivery confirmation response from the destination.

The SG distribution management unit 16 uses the above-mentioned items of the distribution management table 1 and the items added as necessary to manage the tmpACK of the data packet, confirm the reception, and control the retransmission according to the reception result. , TmpACK to source and RR as delivery acknowledgment from destination
It is possible to control the transmission speed of the ACK, control the transfer speed to the destination, and manage the transmission buffer 6 and the reception buffer 7 of the data distribution management device 10.

Using the distribution management table 1, the data distribution management device 10 uses the source IP address and destination IP address in the IP header of the received data packet, and the source port number and destination port number in the TCP header. And whether the communication represented by the combination of the source IP in the IP header and the source port in the TCP header and the combination of the destination IP and the destination port is in the distribution management table 1 or not. Make a decision.
If the result of this determination is that the communication is not registered in the distribution management table 1 (step S27, NO), the process moves to step S22.

When it is determined that the communication is registered in the distribution management table 1 (step S27, YE
S), the process proceeds to step S31, and it is determined whether or not the received data packet is a data packet in the destination reception window. If the received data packet is a data packet in the destination reception window (YES in step S31). If the data packet is not within the destination reception window (step S31, NO), the process proceeds to step S32.
The pACK available flag is set to “OFF”, and information on the data packet is registered in the distribution management table 1, and t
The mpACK available flag is set to "OFF" (step S39), the received data packet is transferred to the destination (step S23), and the process returns to step S11.

On the other hand, if it is determined in step S32 that the data packet is not a data packet for ending communication, step S32 is executed.
Move to 34. In step S34, by referring to the distribution management table 1, it is determined whether the “transmission window size” of the transmission source has reached a specified window size, for example, “2” or more, and the “reception window size” of the destination.
Window size is a prescribed window size, for example, “2”
It is determined whether or not the above has been reached.
If it is determined that the size has reached the window size (step S34, YES), the tmp of the data distribution management device 10
The ACK available flag is set to "OFF" (step S39), the received data packet is transferred to the destination (step S23), and the process returns to step S11. If it is determined in step S32 that the data packet is a communication end data packet (step S32, YES)
Moves to step S40. In step S40, "impossible" and "FIN flag received" are entered in the item D18 relating to tmpACK transmission in the distribution management table shown in FIG. 6, and the process proceeds to step S23.

On the other hand, in step S34, Wind
If it is determined that the ow size is not sufficient, it is determined whether or not the received data packet is a delivery confirmation response from the terminal device C2 (step S35). If it is determined that the received data packet is not a delivery confirmation response from the terminal device C2 (step S35, NO), the information is registered in the distribution management table 1, and the tmpACK available flag is set to "ON" (step S35). (S37), transfer the received data packet to the destination (step S23), and return to step S11. The data packet with the tmpACK available flag set to “ON” is stored in the transmission buffer 6. When performing the processing in step S37, depending on the implementation, information as to whether or not tmpACK can be used is set for each entry of information on each data packet in the distribution management table 1 as information at the time of arrival of the latest data packet. I do. Thereby, for example, at the time of a slow start, the tmpACK use control is not performed.
For example, fine control according to the window size state can be performed.

When it is determined that the received data packet is a delivery confirmation response from terminal device C2 (step S
35, YES), the received data packet is stored in the tmpACK buffer 4, and the S
An event notifying the G distribution management unit 16 that the delivery confirmation response has been received from the terminal device C2 is generated, and t
The mpACK available flag is set to "ON" (step S36), and the process returns to step S11. Note that the processing in step S36 may be performed, for example, depending on the implementation.
It is also possible to store only necessary parts such as only the IP header and the IP data part. Also, the received data packet is already tmpA due to the sequence number or the like.
A determination may be made as to whether or not the data packet is a data packet that is later than the data packet that has been registered as a CK creation data packet, and the latest, that is, the latest data packet may be registered as a tmpACK creation data packet. Also, in step S35, if the received data packet is not a delivery confirmation response from the terminal device C2 (step S35, NO), the received data packet is stored in the tmpACK buffer 4 for tmpACK creation, and the tmpACK is created. It is also possible to use the data at the time of creation.

On the other hand, if it is determined in step S26 that the data packet is a communication start data packet, it is determined whether the communication start data packet including the data packet currently being determined is correctly transmitted and received according to the communication procedure. It is determined whether or not it is (step S29). As a result of a series of operations, only the data packets that have been confirmed to arrive in the correct order for communication start are stored in a start-time packet buffer (not shown). Therefore, this step S2
The judgment of No. 9 is based on whether the received data packet is the first data packet for starting communication or the data packet to be received next to the last received data packet for starting communication in the same communication. You just have to check for one of them.

Thereafter, when it is determined that the data distribution management device 10 has received the data packet for starting communication in the correct order (step S29, YES), the information of this data packet is additionally registered in the distribution management table 1. (Step S30). Thereafter, it is determined whether or not the received data packet is a delivery confirmation response from the terminal device C2 (step S41). If it is determined that the received data packet is a delivery confirmation response from the terminal device C2 (step S41, YES),
After performing the process of step S36 described above, step S36 is performed.
It returns to 11. On the other hand, when it is determined that it is not a delivery confirmation response from the terminal device C2 (step S41, N
O), transfer the received data packet to the destination (step S23), and return to step S11.

On the other hand, when it is determined in step S29 that data distribution management device 10 has not received the data packet for starting communication in the correct order (step S2).
(9, NO) and when it is determined in step S27 that the communication is not the communication registered in the distribution management table 1 (step S27, NO), the tmpACK available flag of the data distribution management device 10 is set to “OFF” (step S22). Then, the received data packet is transferred to the destination (step S23), and the process returns to step S11.

Next, referring to the flowchart shown in FIG. 7, tmpACK in step S13 shown in FIG.
The detailed procedure of the usage control process will be described. FIG. 7 is a flowchart illustrating a procedure for adjusting the transmission timing of tmpACK according to the window size. here,
This adjustment process is performed when a data segment is received and tmp
Referring to the ACK use control flag, the process is started by a tmpACK use control execution event or an event output from a timer or a counter related to the delayed provisional ACK.
The delayed provisional ACK is processed and processed by the data distribution management device 10 by creating and transmitting a provisional ACK (tmpACK) after waiting for reception of a certain time or a certain number of packets, similarly to the method of the delay ACK in the TCP. The purpose is to promote the reduction of the flow with the distribution management device 10.

Therefore, the event output by the timer or counter relating to the delayed temporary ACK is, for example, a case where the delay temporary ACK is created and transmitted by a method of waiting for a certain period of time, and then using tmpACK.
The usage judging unit 12 has a timer for measuring the timing of generating a delayed temporary ACK, a timeout time variable or a constant, and a delayed temporary ACK time elapse flag in which ON and OFF values are set by the timer and a tmpA every predetermined time.
This is generated to inform the CK creating unit 13 that the waiting time for the delayed provisional ACK has come.

Referring to FIG. 7, first, by referring to the value of the FIN reception completion flag set by the series of processes shown in FIG. 3, it is determined whether or not the data packet of the communication end has been received (step S51). ). If it is determined that the FIN packet has been received (step S51, YES), the process returns to step S13. On the other hand, when it is not determined that the FIN packet has been received (step S51, N
O), it is determined whether the data packets stored in the tmpACK buffer 4 are a SYN data packet and an ACK data packet ((SYN + ACK) packet) (step S52). If the packet is a (SYN + ACK) packet (step S52, YES), the packet is not transferred (S52).
YN + ACK) packet to the transmission source, that is, the terminal device C
1 (step S53), and returns to step S13. On the other hand, in step S52, tmpAC
The data packet stored in the K buffer 4 is (SYN
+ ACK) If it is determined that the packet is not a packet (step S52, NO), the distribution management table 1 and the temporary ACK creation stop flag shown in FIG.
With reference to “F”, it is determined whether or not a data segment required for transmitting tmpACK has been received and whether or not temporary ACK can be transmitted (step S54). Whether or not a data segment necessary for transmitting tmpACK has been received is determined, for example, when one or more segments having a later sequence number are received from segment X for which tmpACK is to be created.
An implementation that enables creation of K can be implemented.

If it is determined in step S54 that a data segment required for transmitting tmpACK has not been received (step S54, NO), if there is an untransmitted ACK segment in the tmpACK buffer 4, this ACK segment is deleted. The data is transferred to the terminal device C1 (step S53), and the process returns to step S13.

On the other hand, in step S54, tmpA
When it is determined that the data segment necessary for transmitting the CK has been received (step S54, YES), the data segment from the terminal device C1 for which the tmpACK is to be created is determined (step S55). In the process of step S55, the process is performed by using the distribution management table 1 and referring to the window size of the terminal device C1, the transmission status of tmpACK, the SACK option of the TCP protocol between the terminal devices C1 and C2, and the like.

For example, in the case of communication without the SACK option, the ACK among the entries of the distribution management table 1
Among the segments that are waiting to be received, have not transmitted tmpACK, and have a sequence number smaller than the own sequence number, all of the segments received by the data distribution management device 10 have a sequence number of 2
The next largest one is determined as a target of tmpACK creation.

Thereafter, the acknowledgment number of the segment stored in the tmpACK creation buffer is entered in step S55.
A segment rewritten to the sequence number of the tmpACK creation target segment determined by “1” plus “1” is created as tmpACK (step S5).
6). In the case of TCP with the SACK option, in step S55, tm considering the SACK option
The pACK creation target is determined, and in step S56,
It is also possible to implement an implementation that creates a delivery acknowledgment response with the SACK option.

Thereafter, tmpACK is transmitted to the terminal device C1 as the transmission source (step S57). Here, the transmission timing is adjusted according to the window size. For example, after waiting for a waiting time Wtime _NEW shown in the following equation (1), tmpACK is transmitted. In other _{words, Wtime NEW = Min [UBOUND,} Max [Wtime OLD - (WindowSIZE NEW -WindowSIZE OLD) * α, LBOUND]] is a ... (1). Here, “Wtime _NEW ” is the current waiting time, “LBOUND” is the upper limit of the transmission waiting,
For example, the retransmission timeout value in the terminal device C1 is set. “Wtime _OLD ” is “Wtime _NEW ” calculated last time, and the initial value is “LBOUND”. “WindowSIZE _NEW ” is the current window size of the terminal device C1, and “WindowSIZE _OLD ” is the previous window size of the terminal device C1. "LBOUN
D ”is a lower limit value of waiting for transmission, for example,“ 0 ”;
“Α” represents a predetermined number for calculating “Wtime _NEW ”.

After transferring the tmpACK to the transmission source, all the distribution management tables 1 corresponding to the transmitted tmpACK
TmpACK the information of the segment entered above
The setting is changed to transmitted (step S58), and the
Return to step 13.

Next, with reference to the flowchart shown in FIG. 8, the procedure of the reception confirmation process by the SG distribution management unit 16 of the data distribution management device 10 and the retransmission control process based on the result will be described. The reception confirmation process and the retransmission control process are performed in parallel with the packet check process and the tmpACK use control process shown in FIG.

In FIG. 8, first, it is determined whether or not an event indicating the arrival of a delivery confirmation response from the terminal device C2 has been received (step S61). This event is an event generated in the packet check processing in step S11. If the delivery acknowledgment has arrived (step S61, YES), it is determined whether the notification is a start notification from the terminal device C2 (step S69). The process ends. On the other hand, when it is determined that the notification is not the start notification from the terminal device C2 (step S69, NO), the result for the data segment indicated by the received delivery confirmation response is entered in the distribution management table 1 (step S70).
For example, in the case of communication without the SACK option, of the entries in the delivery management table 1, all data segments that are waiting for ACK reception and have a smaller sequence number than the data segment indicated by the received acknowledgment response are ACKed. Mark received. On the other hand, in the case of the communication with the SACK option, among the entries of the distribution management table 1, the data segment is waiting for ACK reception, has a smaller sequence number than the data segment indicated by the received delivery confirmation response, and , All the data segments not included in the SACK option are assumed to have been received ACK.

After the processing in step S70, the ACK-received segments in the entries of the distribution management table 1 are deleted from the transmission buffer 6 (step S71). Here, the deletion processing of the ACK reception segment may have a timer related to deletion, and may be collectively deleted at regular time intervals.

On the other hand, if it is determined in step S61 that the event of receiving the acknowledgment response from the terminal device C2 has not been received, it is further determined whether or not a retransmission timeout has occurred (step S62). If no retransmission timeout has occurred (step S62, N
O), the process is terminated as it is. On the other hand, when it is determined that a retransmission timeout has occurred (step S62, Y
ES), it is determined whether to stop the transmission of tmpACK (step S63).

Here, the data distribution management device 10 has a pseudo window (simulating a window in TCP communication) corresponding to the reception buffer 7, and subtracts the amount remaining in the reception buffer 7 from the pseudo window size. The amount obtained by subtracting the total amount of the segments received from the transmission source from the calculated amount, that is, the pseudo window size, and adding the total amount of the segments to which the delivery acknowledgment has been sent from the destination is known in the data distribution management device 10. If the size of the window exceeds the window size of the transmission source by one segment, it is determined that tmpACK is not stopped (step S63, NO), and the temporary A shown in FIG.
Set the CK creation stop flag to “OFF” and set tmpAC
A process for starting transmission of K is performed (step S64), and the process proceeds to step S66.

On the other hand, if the reverse is true, it is determined that tmpACK is to be stopped (step S63, YES), and FIG.
Set the temporary ACK creation stop flag shown in
A process for stopping transmission of tmpACK is performed (step S
65), and proceed to step S66. Here, the above-described determination of whether to stop tmpACK or not will be specifically described. The pseudo window size is "X" bytes, the window size of the transmission source, that is, the terminal device C1, which the data distribution management device 10 knows at this time is "m" bytes, and the total amount of segments currently in the reception buffer 7 is "y". Byte, size of one segment to receive is "k"
If the following equation (2) is satisfied, the temporary AC
A determination is made to stop K. That is, X−y <m + k (2).

Thereafter, the number of retransmissions of the entry of the data segment in which the timeout has occurred in the distribution management table 1 is incremented, the retransmission flag is set to “ON” (step S66), and it is determined whether the distribution is completed (step S67). ). When the exchange of the data packet at the end of distribution in the normal TCP communication is detected, or when the timeout of the retransmission is repeated and the data distribution management device 10 terminates the distribution by retrying out the retransmission, it is determined that the distribution is completed. (Step S67, YES),
A distribution end process is performed (step S68), and this process ends. Note that the retransmission timeout value and the number of retry outs need to be set sufficiently longer than the retransmission timeout value and the number of retry outs in the terminal device C1 and the terminal device C2.

The processing in step S68 is different depending on the distribution end state. When the exchange of the data packet at the end of distribution in the normal TCP communication is detected, tmp
In the ACK buffer 4, the transmission buffer 6, and the reception buffer 7, all the data segments in the communication to be ended are deleted, and the entry of the distribution management table 1 is also deleted. It should be noted that the entry of the distribution management table 1 can also be stored while also storing data. Further, the entry may have a lifetime, or may be left as long as the entry does not overflow.

On the other hand, if it is determined in step S67 that distribution has not been completed, retransmission processing in steps S72 to S74 is performed. That is, in step S72, the data segment of the transmission buffer 6 is retransmitted for the retransmission flag of the distribution management table 1 that is “ON”, and the retransmission flag of the distribution management table 1 is set to “OFF”. After the process of step S72, the retransmission timer is reset (step S73), the retransmission counter of the data distribution management device 10 is incremented (step S74), and the process ends.

Embodiment 2 Next, a second embodiment of the present invention will be described. In the second embodiment, FIG.
In the tmpACK use control process shown in (1), a tmpACK creation process and a transmission process are performed by adding a delay according to the window size.

FIG. 9 is a flowchart showing a tmpACK use processing procedure of the data distribution management device according to the second embodiment of the present invention. In FIG. 9, it is determined whether or not the data packet of the communication end has been received with reference to the value of the FIN reception completion flag set by the series of processes shown in FIG. 2 (step S81). If it is determined that the FIN packet has been received (step S81, YES), the process returns to step S13.

On the other hand, when it is not determined that the FIN packet has been received (step S81, NO), it is determined whether or not a flag indicating that the delay time for provisional ACK has elapsed is set (step S82). If the temporary ACK delay time has elapsed (step S82, YES), the delay temporary ACK timer and the related flag are reset (step S83).

At this time, for example, using the correspondence table shown in FIG.
Update the timer value. For example, in FIG.
If the window size is 5 kbytes or more,
Update and set the delay timer to "5" msec. After that, it moves to step S84.

If it is determined in step S82 that the delay time for provisional ACK has not elapsed, the data distribution management device 10 determines whether or not there is any data not yet transferred to the terminal device C1 (step S86). When there is no untransferred data (step S86, NO), the process returns to step S13, and when there is untransferred data (step S86, YES), the process proceeds to step S87.

In step S87, the data packet stored in the tmpACK buffer 4 is (SYN + A
CK) to determine whether the packet is (SYN + AC)
K) If it is a packet, the untransmitted (SYN + AC
K) Transfer the packet to the destination (step S85), and return to step S13.

On the other hand, in step S87, tmpA
The data packet stored in the CK buffer 4 is (SY
N + ACK) If it is determined that the packet is not a packet, tmp
It is determined whether a data segment necessary for transmitting ACK has been received (step S88). Step S8
4 and step 88, the delivery management table 1
And the on / off state of the temporary ACK creation flag, and tm
It is determined whether a segment necessary for transmission of pACK has been received and whether transmission of tmpACK is possible. That is, it is determined whether or not to use tmpACK with delay. The determination as to whether or not a segment necessary for tmpACK transmission has been received may be made, for example, by generating a tmpACK for segment X when one or more segments having a sequence number subsequent to segment X for which tmpACK is to be generated are received. Is possible.

In step S84, tmp with a delay
If it is determined that ACK is not used, the ACK packet in the tmpACK buffer 4 that has not been transferred is transferred to the terminal device C1 (step S85), and the process returns to step S13.

On the other hand, in steps S84 and S88,
If it is determined to use tmpACK with delay, tm
The data segment from the terminal device C1 for which the pACK is to be created is determined (step S89). In the process of this step 89, the reception status, the window size of the transmission source, the tmpACK transmission status, and the terminal device C in the data distribution management device 10 are used by using the distribution management table 1.
SACK of TCP protocol between terminal device 1 and terminal device C2
Perform processing with reference to options.

For example, in the case of communication without the SACK option, ACK among the entries of the distribution management table 1
Among the segments that are waiting to be received, have not transmitted tmpACK, and have a smaller sequence number than their own sequence numbers, the segments whose sequence numbers are The second largest one is determined as a tmpACK creation target.

Also, for example, in the case of communication with the SACK option, tmpACK transmission is possible and t
The mpACK has not been transmitted, is waiting for ACK reception, and is received by the data distribution management device 10 in which the number of unreceived segments having a continuous sequence number is four or less among the segments having the small own sequence number. Among the existing segments, the segment whose sequence number is one before the last one is determined as a target of tmpACK generation and transmission.

After the processing of step S89, the acknowledgment number of the data segment stored in the tmpACK buffer 4 is determined by the tmpAC determined in step S89.
The data segment rewritten to a number obtained by adding “1” to the sequence number of the data segment for which K is to be created,
Create as tmpACK. In the case of TCP with the SACK option, it is also possible to mount tmpACK in consideration of the SACK option in step S89. Thereafter, in step S90, a delivery confirmation response including the SACK option is created.

After the processing in step S90, tmpACK is transmitted to the terminal device C1 (step S91), and the information of the data segment entered in all the distribution management tables 1 corresponding to the transmitted tmpACK is transmitted to tmpA.
Change and set to CK transmission completed (step S92), and return to step S13.

[0089]

As described above, according to the present invention, the holding means holds the information on the window size of the first terminal device, and the deciding means holds the information on the window size held by the holding means. It is determined whether or not to perform the return processing of the delivery acknowledgment based on the, the control means, the return processing of the delivery acknowledgment only when the determination means determines to perform the return processing of the delivery acknowledgment To do
Since the transmission timing or the transmission volume of the acknowledgment response to the transmission source is adjusted, data can be distributed more quickly and efficiently, and a rapid data transmission speed or There is an effect that a data distribution management device that can avoid an increase in the amount of data can be realized.

According to the next invention, the holding means holds the information on the window size of the first terminal device, and the control means sets the information in accordance with the window size indicated by the information on the window size held by the holding means. Since the control for changing the return timing of the delivery acknowledgment for the data transmitted by the first terminal device is performed, a data delivery management device capable of performing data delivery more quickly and efficiently is realized. It has the effect of being able to do so.

According to the next invention, the calculating means calculates the delay time from the point in time of receiving the acknowledgment response received from the second terminal apparatus to the point in time of returning the acknowledgment response to the first terminal apparatus. A second value obtained by multiplying a first subtraction value obtained by subtracting a previous window size from a current window size in the first terminal device from a current delay time having a substantially corresponding predetermined lower limit as an initial value, by a predetermined value. The second subtraction value obtained by subtracting the value of the above, the maximum value of the predetermined lower limit value is calculated, and the minimum value of the maximum value and the predetermined upper limit value is calculated,
The process of resetting the minimum value as the current delay time is repeated to calculate the latest current delay time, and the control unit determines the second current delay time according to the latest current delay time calculated by the calculation unit. Since the control for changing the return timing of the delivery acknowledgment for the data transmitted by the one terminal device is performed, it is possible to realize a data distribution management device that can perform data distribution more quickly and efficiently. It has the effect of being able to.

According to the next invention, the holding means stores the window size of the first terminal device, the number of segments of the data received from the first terminal device, and the reception confirmation response from the second terminal device. At least the presence / absence of the transmission confirmation response to the data transmitted by the first terminal device based on a combination of the window size, the number of segments, and the presence / absence of the reception confirmation response held by the holding unit. It is determined whether or not to return the acknowledgment, and if the control means determines that the acknowledgment is to be returned, the acknowledgment is returned. There is an effect that it is possible to realize a data distribution management device capable of performing data distribution.

[0093] According to the next invention, the holding means holds the information on the window size of the first terminal device, and the control means sets the information in accordance with the window size indicated by the information on the window size held by the holding means. Since the creation density of the delivery acknowledgment with respect to the data transmitted by the first terminal device is variable, for example, the control for thinning out the delivery acknowledgment is performed, so that data can be distributed more quickly and efficiently. There is an effect that a distribution management device can be realized.

According to the next invention, the data buffer is:
At least the data transmitted by the first terminal device is retained, the management means manages at least the registration information of the data transmitted by the first terminal device, and the deletion control means transmits the data transmitted by the first terminal device. When receiving a delivery acknowledgment for the data from the second terminal device to which the data has been transferred, the control unit deletes the data held in the data buffer and the registration information of the data managed by the management unit. Since this is performed, the load on the data distribution management device can be reduced.

[0095] According to the next invention, the counting means counts the number of delivery-confirmed segments, which are data to be deleted, of the data held in the data buffer, and the deletion control means sets Each time a delivery confirmation response to the data transmitted from the second terminal device to which the data transmitted by the first terminal device has been received is set, the registration information is set to delivery confirmed in the data managed by the management means, If the number of segments set as delivery confirmed counted by the means exceeds a predetermined number, the delivery confirmed data held in the data buffer and the delivery confirmed data managed by the management means. Since the registered information is deleted, the load on the data distribution management device can be reduced.

According to the next invention, the first counting means includes:
The number of segments whose delivery has been confirmed, which is the data to be deleted among the data held in the data buffer, is counted, and the second counting means calculates the number of segments to be deleted among the data managed by the management means. The registration information is counted, and each time the deletion control unit receives the delivery confirmation response to the data from the second terminal device to which the data transmitted by the first terminal device is transferred, the deletion control unit manages the registration information. When information relating to data is set as delivery confirmed, and when the number of segments set as delivery confirmed counted by the first counting means exceeds a first predetermined number, the data held in the data buffer is stored. If the data whose delivery has been confirmed is deleted and the registration information of the data whose delivery has been confirmed counted by the second counting means exceeds a second predetermined number, the registration information of the data whose delivery has been confirmed is deleted. Since so as to remove an effect that it is possible to reduce the load on the data distribution management device.

[0097] According to the next invention, the clocking means further includes a clocking means for clocking a predetermined time, and the deletion control means transmits the data transmitted by the first terminal device to the second terminal device. Each time a delivery confirmation response to the data is received, the registration information is set to delivery confirmed in the data managed by the management means, and when the timing means times the predetermined time, the data is held in the data buffer. Since the registered data of the delivery-confirmed data and the delivery-confirmed data managed by the management unit are deleted, the load on the data distribution management device can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a data distribution management system including a data distribution management device according to a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating a data distribution management processing procedure performed by the data distribution management device illustrated in FIG. 1;

FIG. 3 is a detailed flowchart showing a procedure of a packet check process shown in FIG. 2;

FIG. 4 is a diagram showing an example of the contents of a route management table shown in FIG. 1;

FIG. 5 is a diagram showing an example of the contents of a protocol management table shown in FIG. 1;

FIG. 6 is a diagram showing an example of the contents of a distribution management table shown in FIG. 1;

FIG. 7 is a detailed flowchart showing a tmpACK use control processing procedure shown in FIG. 2;

8 is a flowchart showing a procedure of a reception confirmation process and a retransmission control process by the data distribution management device shown in FIG.

FIG. 9 is a detailed flowchart showing a tmpACK use control processing procedure by the data distribution management device according to the second embodiment of the present invention.

10 is a diagram illustrating an example of a correspondence table indicating a correspondence between a window size and a set value of a delay timer included in the data distribution management device illustrated in FIG. 9;

FIG. 11 is a block diagram showing a configuration of a data distribution management system including a conventional data distribution management device.

[Explanation of symbols]

1 delivery management table, 1a route management table, 2
a, 2b, 3 lines, 4tmp ACK buffer, 5 protocol management table, 6 transmission buffer, 7 reception buffer, 10, 20 data distribution management device, 10a gateway function unit, 11, 17 communication unit, 12 tmpA
CK use determination unit, 13 tmpACK creation unit, 14 S
GTimer counting section, 15 delivery data recording section, 1
6 SG distribution management unit, C1, C2 terminal device.

Claims (9)

[Claims] An arrangement is made on a transmission path between a first terminal device for performing communication requiring a delivery acknowledgment for transmitted data and a second terminal device which is a communication partner of the first terminal device. Wherein the transmission delay between the first terminal device and the second terminal device is smaller than the transmission delay between the first terminal device and the second terminal device. A data transfer management device capable of performing a transfer process for transferring data to the first terminal device and a return process for generating and returning a delivery acknowledgment response to the transferred data. Means, determining means for determining whether or not to perform the return processing of the acknowledgment response based on the information on the window size held by the holding means, and when the determining means performs the return processing of the acknowledgment response And a control unit for performing a process of returning the delivery acknowledgment when the determination is made. 2. A transmission terminal disposed on a transmission path between a first terminal device that performs communication requiring a delivery confirmation response to transmitted data and a second terminal device that is a communication partner of the first terminal device. Wherein the transmission delay between the first terminal device and the second terminal device is smaller than the transmission delay between the first terminal device and the second terminal device. A data transfer management device capable of performing a transfer process for transferring data to the first terminal device and a return process for generating and returning a delivery acknowledgment response to the transferred data. Means for varying the return timing of the delivery acknowledgment for the data transmitted by the first terminal device according to the window size indicated by the window size information held by the holding means Data distribution management apparatus characterized by comprising a control means for control, a. 3. Initializing a predetermined lower limit value substantially corresponding to a delay time from a time point of receiving a delivery confirmation response received from the second terminal apparatus to a time point of returning a delivery confirmation response to the first terminal apparatus. From the current delay time as a value, the first
Maximum value of a second subtraction value obtained by subtracting a second value obtained by multiplying a first subtraction value obtained by subtracting a previous window size from a current window size from a current window size by a predetermined value, and the predetermined lower limit value Calculation means for calculating the maximum value and the minimum value of the predetermined upper limit value, and repeating the process of resetting the minimum value as the current delay time to calculate the latest current delay time. The apparatus further includes: the control unit performs control to vary a return timing of the delivery confirmation response to data transmitted by the first terminal device according to a latest current delay time calculated by the calculation unit. The data distribution management device according to claim 2, wherein: 4. A transmission terminal arranged on a transmission path between a first terminal device for performing a communication requiring a delivery acknowledgment for transmitted data and a second terminal device which is a communication partner of the first terminal device. Wherein the transmission delay between the first terminal device and the second terminal device is smaller than the transmission delay between the first terminal device and the second terminal device. A data delivery management device capable of performing a transfer process for transferring the data to the first terminal and a return process for generating and returning a delivery confirmation response to the transferred data. The window size of the first terminal device and the first terminal Holding means for holding at least the number of segments of data received from the device and the presence or absence of a reception confirmation response from the second terminal device; the window size and the segment held by the holding means Deciding means for deciding whether to return the acknowledgment response to the data transmitted by the first terminal device based on a combination of the acknowledgment and the presence or absence of the acknowledgment response. Control means for returning the delivery acknowledgment when it is determined that the data delivery management is to be performed. 5. A transmission terminal arranged on a transmission path between a first terminal device that performs communication requiring a delivery acknowledgment for transmitted data and a second terminal device that is a communication partner of the first terminal device. Wherein the transmission delay between the first terminal device and the second terminal device is smaller than the transmission delay between the first terminal device and the second terminal device. A data transfer management device capable of performing a transfer process for transferring data to the first terminal device and a return process for generating and returning a delivery acknowledgment response to the transferred data. Means for controlling the generation density of the delivery acknowledgment for the data transmitted by the first terminal device in accordance with the window size indicated by the window size information held by the holding means. Data distribution management apparatus characterized by comprising: a power sale control means. 6. A data buffer for holding at least data transmitted by the first terminal device, a managing unit for managing registration information of at least data transmitted by the first terminal device, and a first terminal device Receiving a delivery acknowledgment for the data from the second terminal device to which the transmitted data has been transferred, deletes the data held in the data buffer and the registration information of the data managed by the management unit. The data distribution management device according to claim 1, further comprising: a deletion control unit that performs control. 7. The data processing apparatus according to claim 1, further comprising a counting unit that counts the number of segments whose delivery has been confirmed, which is data to be deleted, of the data held in the data buffer, wherein the deletion control unit is configured to delete the first terminal device. Each time a transmission acknowledgment for the data is received from the second terminal device that has transmitted the data transmitted, the registration information is set to acknowledgment in the data managed by the management means, and the counting means counts. When the number of segments set as the delivery confirmation exceeds a predetermined number, the delivery confirmation data held in the data buffer and the registration information of the delivery confirmation data managed by the management unit are stored. The data distribution management device according to claim 6, wherein the data distribution management device deletes the data. 8. A first counting means for counting the number of delivery-confirmed segments which are data to be deleted among the data held in the data buffer, and a deletion of data managed by the management means. A second counting unit that counts registration information of target data, wherein the deletion control unit transmits the data transmitted from the first terminal device to the second terminal device that has transmitted the data. Each time an acknowledgment is received, the information about the data managed by the management means is set to delivery confirmed, and the number of segments set to delivery confirmed by the first counting means is equal to the first predetermined number. If it exceeds, the data whose delivery has been confirmed held in the data buffer is deleted, and the registration information of the data whose delivery has been confirmed counted by the second counting means is a second predetermined number. 7. The data distribution management device according to claim 6, wherein the registration information of the data whose delivery has been confirmed is deleted when the number exceeds the limit. 9. The system according to claim 1, further comprising a timer for counting a predetermined time, wherein the deletion controller receives a delivery confirmation response to the data from the second terminal to which the data transmitted by the first terminal has been transferred. In each case, the registration information is set to delivery confirmed in the data managed by the management means, and when the timing means times the predetermined time, the delivery confirmed data held in the data buffer and 7. The data distribution management device according to claim 6, wherein registration information of the data whose delivery has been confirmed managed by the management unit is deleted.