JP2014116775A - Network system, bandwidth control method, and bandwidth control apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the bandwidth utilization in a system for communications among multiple sites.SOLUTION: A network system comprises a plurality of communication devices accommodating a plurality of sessions and a bandwidth control server connecting with each of the communication devices. The bandwidth control server comprises a memory and a network interface. The bandwidth control server has in the memory, communication quality information including information for calculating a minimum bandwidth required to be allocated at least to each of the sessions; receives from each of the communication devices, session information regarding a session accommodated by the communication device via the network interface; allocates the sessions the respective minimum bandwidths on the basis of the received session information and the communication quality information; and notifies the communication devices of the respective minimum bandwidths allocated.

Description

  The present invention relates to a network system.

  With regard to communication in a wide area network connecting distributed bases, there are problems of delay and packet discard rate, and reduction in communication efficiency due to these. As a method for solving such problems, there is a technology for realizing high-speed communication between bases by installing a communication speed-up device for speeding up communication in a wide area network at each base so that the bases face each other. Proposed.

  The communication speed-up device is equipped with a cache to shorten the access time to the file, and the transmission control protocol / internet protocol (TCP / IP), which is one of the basic protocols of the network, is speeded up and required for data transfer. A plurality of methods have been developed, such as a method for shortening time, a method for performing high-speed processing specialized for a specific communication protocol such as Hyper Text Transfer Protocol (HTTP), or Common Internet File System (CIFS). In the case where the acceleration apparatus is arranged at a plurality of bases and communication between bases is performed, suppression of congestion becomes a problem.

  For example, consider a case where there are three bases in the system, and devices A, B, and C are installed at the respective bases and communicate with each other. The bandwidth of each base is 100 Mbps at the maximum, and devices A and B transmit data to device C. Since the device bandwidths of the devices A and B are 100 Mbps, the devices A and B try to communicate with the device C using the entire bandwidth of 100 Mbps. However, the device bandwidth of the device C is 100 Mbps, which is smaller than the sum of the device bandwidths of the devices A and B, 200 Mbps. For this reason, congestion occurs between the devices A and C and between the devices B and C.

  In order to perform congestion control, a plurality of techniques for performing bandwidth control on a single device or the entire network have been proposed. As a technology that performs congestion control by a single device, the status of communication sessions is monitored, and when congestion occurs, the bandwidth used is reduced, or the bandwidth for sessions whose session duration exceeds the specified value is reduced to suppress congestion. The technique which performs is proposed (for example, refer patent document 1 and patent document 2).

  In addition, as a technology for performing bandwidth control for the entire network, a technology has been proposed in which bandwidth is adjusted for each device in the network, and bandwidth adjustment is performed by regarding a device that has been discarded as a bottleneck. (For example, refer to Patent Document 3).

JP 2010-177797 A JP 2006-197110 A JP 2012-0665135 A

  When communication is performed between a plurality of bases, in addition to congestion control, bandwidth guarantee and effective use of communication bandwidth become issues. For example, when communication from a plurality of bases is concentrated on one base, it is necessary to ensure a minimum communication quality according to the number or type of communication sessions. Further, when a plurality of bases having different bands communicate with each other, unused bands are generated. For example, when the base A having a bandwidth of 100 Mbps and the base B having a bandwidth of 50 Mbps communicate, the communication bandwidth between the base A and the base B is limited to 50 Mbps of the base B, and the remaining 50 Mbps of the base A is not used. It becomes. Such unused bandwidth causes a decrease in network utilization efficiency.

  A typical example of the present invention is as follows. That is, a network system including a plurality of communication devices that accommodate a plurality of sessions, and a bandwidth control server connected to each of the plurality of communication devices, the bandwidth control server including a memory and a network interface And having in the memory communication quality information including information for calculating a minimum bandwidth that should be allocated at least to each of the plurality of sessions, and accommodated by the communication device from each of the plurality of communication devices Session information relating to a session is received via the network interface, and based on the received session information and the communication quality information, the minimum bandwidth is allocated to each of the plurality of sessions, and the allocated minimum Each of the bands is notified to each of the plurality of communication devices.

  According to an embodiment of the present invention, it is possible to improve a bandwidth utilization rate by allocating a bandwidth for each session according to a session.

  Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

It is a block diagram which shows the example of a structure of the band control system of a present Example. It is explanatory drawing which shows the structure of the bandwidth control server of a present Example. It is explanatory drawing which shows the structure of the communication speed-up apparatus of a present Example. It is a sequence diagram which shows the process in which the communication speed-up apparatus of a present Example registers its own apparatus to a bandwidth control server. It is a sequence diagram which shows the process which the communication speed-up apparatus 2 registers its own apparatus to a bandwidth control server, when the communication speed-up apparatus of a present Example is preset with communication quality information. It is a sequence diagram which shows the bandwidth allocation process of a present Example. It is a block diagram which shows the example of the band control system at the time of performing the band allocation process of a present Example. It is explanatory drawing which shows DB before the minimum zone | band is calculated by the service zone | band designation | designated of a present Example. It is a flowchart which shows the process which calculates the minimum zone | band by the service zone designation | designated of a present Example. It is explanatory drawing which shows the minimum zone | band calculated by the service zone | band designation | designated of a present Example. It is explanatory drawing which shows the result of having adjusted the minimum zone | band by the service zone designation | designated of a present Example. It is explanatory drawing which shows communication quality information DB when the minimum band allocation process by the service band relative designation | designated of a present Example is performed. It is a flowchart which shows the process which calculates the minimum zone | band by the service zone relative designation | designated of a present Example. It is explanatory drawing which shows the minimum zone | band calculated by the service zone | band designation | designated of a present Example. It is explanatory drawing which shows the result of having adjusted the minimum zone | band by the service zone relative designation | designated of a present Example. It is explanatory drawing which shows communication quality information DB in case the allocation of the minimum band by session band designation | designated of a present Example is performed. It is a flowchart which shows the process which calculates the minimum zone | band by the session zone designation | designated of a present Example. It is explanatory drawing which shows communication quality information DB to which the maximum number of sessions of a present Example was set. It is explanatory drawing which shows the minimum zone | band calculated by the session zone | band designation | designated of a present Example. It is explanatory drawing which shows the result of having adjusted the minimum zone | band by session zone designation | designated of a present Example. It is explanatory drawing which shows communication quality information DB165 when the allocation of the minimum band by designation | designated session band specific gravity of a present Example is performed. It is a flowchart which shows the process which calculates the minimum zone | band by session zone specific gravity designation | designated of a present Example. It is explanatory drawing which shows the minimum zone | band calculated by the session zone | band specific gravity designation | designated of a present Example. It is explanatory drawing which shows the result of having adjusted the minimum zone | band by session zone specific gravity designation | designated of a present Example. It is explanatory drawing which shows communication quality information DB in the session band allocation process by the service band designation | designated of a present Example. It is a flowchart which shows the session band allocation process by the service band designation | designated of a present Example. It is explanatory drawing which shows the upper limit zone | band calculated by the service zone | band designation | designated of a present Example. It is explanatory drawing which shows the result of the session band allocation process by the service band designation | designated of a present Example. It is explanatory drawing which shows communication quality information DB in the session band allocation process by the service band relative designation | designated of a present Example. It is a flowchart which shows the session band allocation process by the service band relative designation | designated of a present Example. It is explanatory drawing which shows the upper limit band calculated by the service band relative designation | designated of a present Example. It is explanatory drawing which shows the result of the session band allocation process by the service band relative designation | designated of a present Example. It is explanatory drawing which shows communication quality information DB in the session band allocation process by the session band designation | designated of a present Example. It is a flowchart which shows the session bandwidth allocation process by the session bandwidth designation | designated of a present Example. It is explanatory drawing which shows the upper limit zone | band calculated by the session zone | band designation | designated of a present Example. It is explanatory drawing which shows the result of the session bandwidth allocation process by the session bandwidth designation | designated of a present Example. It is explanatory drawing which shows communication quality information DB in the session band allocation process by the session band specific gravity designation | designated of a present Example. It is a flowchart which shows the session band allocation process by the session band specific gravity designation | designated of a present Example. It is explanatory drawing which shows the upper limit zone | band calculated by the session zone | band specific gravity designation | designated of a present Example. It is explanatory drawing which shows the result of the session band allocation process by session band specific gravity designation | designated of a present Example. It is a block diagram which shows the example of the band control system at the time of allocating a different band for every session of a present Example. It is explanatory drawing which shows session information DB holding the data amount in a buffer of a present Example. 1 is a block diagram showing a bandwidth control system in which a plurality of departments are included in a base of the present embodiment. It is explanatory drawing which shows the communication speed-up apparatus which hold | maintains the information regarding the department of a present Example. It is explanatory drawing which shows the bandwidth control server which hold | maintains the information regarding the department of a present Example. It is a sequence diagram which shows the process which allocates a band for every department of a present Example. 1 is a block diagram showing a bandwidth control system in which a plurality of communication speed-up devices are included in a base of the present embodiment. It is explanatory drawing which shows the bandwidth control server provided with the management function of the apparatus group of a present Example. It is explanatory drawing which shows the communication speed-up apparatus provided with the management function of the apparatus group of a present Example. It is a block diagram which shows the structure of the communication speed-up apparatus with which the terminal / server of a present Example is provided. It is a sequence diagram which shows the registration process to the system of the communication speed-up apparatus of a present Example. It is a sequence diagram which shows the apparatus registration process in case a communication speed-up apparatus manages the communication quality information of a present Example. It is a flowchart which shows the band allocation process in case the communication speed-up apparatus of a present Example belongs to a group. It is explanatory drawing which shows the example of communication speed-up apparatus information DB of a present Example. It is explanatory drawing which shows session information DB after adjusting the upper limit band of a present Example. It is explanatory drawing which shows the surplus band in the communication speed-up apparatus of a present Example. It is a flowchart which shows the residual band recursive allocation system of a present Example. It is explanatory drawing which shows the example of session information DB in the reallocation process of the surplus bandwidth of a present Example. It is explanatory drawing which shows the example of the surplus bandwidth information after the 1st surplus bandwidth allocation process of a present Example. It is explanatory drawing which shows the example of session information DB after the 2nd remainder bandwidth allocation process of a present Example. It is a flowchart which shows the maximum remainder band priority allocation system of a present Example. It is explanatory drawing which shows the surplus bandwidth information after the surplus bandwidth allocation process by the maximum surplus bandwidth priority allocation system of a present Example. It is a sequence diagram which shows the whole flow of the band allocation process of a present Example. It is explanatory drawing which shows the bandwidth control server provided with the switching function of the surplus bandwidth allocation algorithm of a present Example. It is a sequence diagram which shows the process which switches the remainder band allocation algorithm of a present Example dynamically. It is a sequence diagram which shows a process when the bandwidth control server of a present Example stops. It is a block diagram which shows the structure of the communication speed-up apparatus provided with the band allocation function of a present Example. It is a flowchart explaining operation | movement of the bandwidth control server of a present Example. It is a flowchart which shows the process of the communication speed-up apparatus of a present Example. It is explanatory drawing which shows the example of 1st set of the message format of a present Example. It is explanatory drawing which shows the 2nd example of the message format of a present Example. It is explanatory drawing which shows the 3rd example of the message format of a present Example.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram illustrating an example of the configuration of the bandwidth control system according to the present embodiment.

  The bandwidth control system includes a plurality of bases 5 (5-1 to 5-N), a plurality of communication speed-up devices 2 (2-1 to 2-N), a bandwidth control server 1, a plurality of terminals / servers 3, and A network 4 is provided. The communication speed increasing device 2 speeds up communication between the bases 5. The bandwidth control server 1 collects information related to the communication status such as the bandwidth and the session in communication from the communication speedup device 2 and performs bandwidth control on the communication speedup device 2.

  The terminal / server 3 is a terminal or server that communicates with each other through the communication speed-up device 2. The communication speed increasing device 2 and the bandwidth control server 1 are connected to each other through the network 4.

  FIG. 2 is an explanatory diagram illustrating the configuration of the bandwidth control server 1 of the present embodiment.

  FIG. 2A is a block diagram illustrating a configuration of the bandwidth control server 1 according to the present embodiment.

  The bandwidth control server 1 includes a plurality of processing units connected to the bus 18. The plurality of processing units included in the bandwidth control server 1 are a control unit (CPU) 12, an internal storage device 16 such as a memory, an external storage device 14 such as a hard disk, and a network interface 10. The bandwidth control server 1 communicates with the network 4 via the network interface 10.

  The internal storage device 16 includes a bandwidth allocation program 161, a communication speed increasing device information DB (database) 163, a communication quality information DB 165, and a session information DB 167. The bandwidth allocation program 161 allocates an optimal communication bandwidth to each communication speed-up device 2.

  The communication speedup device information DB 163 holds information on the communication speedup device 2. The communication quality information DB 165 holds information related to communication quality such as the type of communication service and the minimum bandwidth in the system. The session information DB 167 holds information related to a communication session between the communication speed increasing devices 2.

  The three databases of the communication speed-up device information DB 163, the communication quality information DB 165, and the session information DB 167 may be stored in the external storage device 14 according to the system scale of the bandwidth control server 1 or the processing performance. These databases are read and written by the bandwidth allocation program 161 installed in the internal storage device 16.

  The control unit (CPU) 12 is a processor such as a CPU. When the control unit (CPU) 12 accesses the bandwidth allocation program 161 stored in the internal storage device 16, the bandwidth control server 1 can execute the control function of this embodiment.

  FIG. 2B is an explanatory diagram illustrating the communication speedup apparatus information DB 163 according to the present embodiment.

  The communication speed increasing device information DB 163 is a database that holds basic information of the communication speed increasing device 2 constituting the system. The communication speedup device information DB 163 should be guaranteed at least within the device identifier 1631 of the communication speedup device 2, the device address 1632 of the communication speedup device 2, the device bandwidth 1633 that is the communication bandwidth of the device, and the base 5. The minimum bandwidth limit 1634 is included as an element.

  The communication band (device band 1633) of the base 5 is a band that can be used at the maximum in the base 5 of the communication speed-up device 2 indicated by the device identifier 1631. For example, the communication band of the base 5 is determined by the contract band with the communication carrier.

  The minimum bandwidth limit 1634 is the maximum value of the minimum bandwidth that is guaranteed at least within the range of the device bandwidth 1633 at the base 5 of the communication speed-up device 2 indicated by the device identifier 1631. The minimum bandwidth limit 1634 is set for the purpose of preventing most of the device bandwidth 1633 from being occupied only by the minimum guaranteed bandwidth.

  FIG. 2C is an explanatory diagram showing the communication quality information DB 165 of this embodiment.

  The communication quality information DB 165 is a database that manages information related to the type of communication session service, communication quality, and the like. The device identifier 1650 that identifies the communication speed-up device 2, the service identifier 1651 that identifies the service, the communication session information A transmission source address 1652, a communication session destination address 1653, a TCP / IP port number 1654, a minimum bandwidth setting value 1656, a minimum bandwidth setting type 1655, a bandwidth setting value 1658, and a bandwidth setting type 1657 are included as elements.

  The service identifier 1651 is the name of the service, and may be a general name such as “Web service” or a protocol name such as “HTTP”. The source address 1652 and the destination address 1653 of the communication session specify addresses used for communication.

  The method of designating the address in the source address 1652 and the destination address 1653 may be a method of designating the address of the terminal / server 3 directly. In addition, a method of designating a plurality of terminals / servers 3 in the network at once using addresses of the network to which the terminal / server 3 belongs, or all terminals / servers targeting any address by wildcard A method of designating 3 may be used.

  The port number 1654 specifies a port number generally used in the network system. As a result, the type of service is specified from the port number 1654.

  For example, port 80 is used for a web service, and port 21 is used for a data transfer service using File Transfer Protocol (FTP). By specifying these port numbers, the port number 1654 can identify the target service.

  The minimum bandwidth setting value 1656 is a setting value for calculating the minimum bandwidth for each service, and the minimum bandwidth setting type 1655 indicates the type of designation method of the minimum bandwidth setting value 1656.

  The bandwidth setting value 1658 indicates a setting value in the bandwidth allocation method for each service used when the remaining bandwidth existing in the communication speed increasing device 2 is allocated to the service or the like even after the minimum bandwidth is allocated to the service or the like. The bandwidth setting type 1657 indicates the type of method for allocating the remaining bandwidth to a service or the like.

  The values indicated by the minimum bandwidth setting type 1655 and the bandwidth setting type 1657 of the present embodiment are any of the following four band allocation algorithm methods. The first method is service band designation, in which the allocated band is directly designated for each service. The second method is a service band relative designation, in which a band allocated to each session is designated by a relative band ratio determined for each service. The third method is a session bandwidth specification, in which a bandwidth allocated for each session is directly specified. The fourth method is session band specific gravity designation, which is a method of designating the specific gravity of a band allocated for each session.

  A bandwidth calculation method corresponding to each designation method will be described later.

  Items related to communication quality included in the communication quality information DB 165 may be individually set for each communication speed-up device 2 or may be set uniformly in the bandwidth control system, and all the communication speed-up devices 2 share the settings. It may be set as follows. When unified setting is performed in the bandwidth control system, an identifier indicating “all devices” is stored in the device identifier 1650.

  FIG. 2D is an explanatory diagram illustrating the session information DB 167 according to this embodiment.

  The session information DB 167 is a database that manages information on communication sessions existing in the system, and includes a device identifier 1670 of the communication speedup device 2 in which the session exists, a session identifier 1671 that identifies the session, a session source address 1672, The session destination address 1673, the communication type 1673, the transmission source port number 1675, the destination port number 1676, the amount of data 1677 in the buffer stored in the buffer related to the session, the upper limit bandwidth 1678 of the session, and the lowest bandwidth 1679 are used as elements. Including.

  In the transmission source address 1652 and the destination address 1653, not the address of the communication speed increasing device 2, but the address of the terminal / server 3 serving as the end point of the session is set.

  The communication type 1674 indicates the type of session indicated by the session identifier 1671 recognized by the communication speed-up device 2 indicated by the device identifier 1670 by “transmission” or “reception”. The transmission source port number 1675 and the destination port number 1676 indicate the port numbers used for communication by the terminal / server 3 serving as the end point of the session, similarly to the transmission source address 1672 and the destination address 1673.

  The data amount 1677 in the buffer indicates the amount of data accumulated in the buffer corresponding to the communication type 1674. If the communication type 1674 is “transmission”, the data amount 1677 in the buffer indicates the data amount of the transmission buffer, and if the communication type 1674 is “reception”, the data amount of the reception buffer is indicated.

  The upper limit band 1678 indicates the upper limit value of the band allocated to the session indicated by the session identifier 1671. The minimum bandwidth 1679 indicates a bandwidth that is at least guaranteed for the session indicated by the session identifier 1671. The type of transmission / reception is the same as the communication type 1673.

  FIG. 3 is an explanatory diagram showing the configuration of the communication speed-up device 2 of this embodiment.

  FIG. 3A is a block diagram showing the configuration of the communication speed-up device 2 of this embodiment.

  The communication acceleration device 2 includes a control unit (CPU) 22 connected to a bus 28, an internal storage device 26 such as a memory, an external storage device 24 such as a hard disk, and one or more network interfaces 20 (in FIG. 2, a network). 2), and communicates with the network 4 via the network interface 20.

  The internal storage device 26 includes a communication speed-up program 261 that speeds up communication between the bases 5, a device basic information DB 263 that holds basic information of the communication speed-up device 2, and a communication service type and a communication speed in the communication speed-up device 2. A communication quality information DB 265 that holds information related to communication quality such as a band setting value, and a session information DB 267 that holds information related to a communication session between the communication speed increasing devices 2 are included.

  The three databases of the device basic information DB 263, the communication quality information DB 265, and the session information DB 267 may be stored in the external storage device 24 according to the system scale and processing performance of the communication speed increasing device 2. These databases are read and written by a communication speed increasing program 261 installed in the internal storage device 26. When the control unit (CPU) 22 accesses the communication speed-up program 261 stored in the internal storage device 26, the control function of the communication speed-up device 2 of this embodiment is implemented.

  FIG. 3B is an explanatory diagram showing the device basic information DB 263 of this embodiment.

  The device basic information DB 263 is a database that manages basic information of the communication speed increasing device 2, and includes a device identifier 2631 of the communication speed increasing device 2, a device address 2632 of the communication speed increasing device 2, a device band 2633 of the base 5, The minimum bandwidth limit amount 2634 to be guaranteed at least within the base 5 is included as an element.

  The elements of the device bandwidth 2633 and the minimum bandwidth limit 2634 are the same as the elements of the same name in the communication speed-up device information DB 163 of the bandwidth control server 1. That is, the device identifier 2631, the device address 2632, the device bandwidth 2633, and the minimum bandwidth limit amount 2634 are changed to the device identifier 1631, the device address 1632, the device bandwidth 1633, and the minimum bandwidth limit amount 1634 of the communication speed-up device information DB 163. Equivalent to.

  FIG. 3C is an explanatory diagram illustrating the communication quality information DB 265 of the present embodiment.

  The communication quality information DB 265 is a database that manages information related to the type of communication session service, communication quality, and the like. The service identifier 2651 that identifies the service, the transmission source address 2652 of the communication session, the destination address 2673 of the communication session, the TCP / IP port number 2654, minimum bandwidth setting type 2655, minimum bandwidth setting value 2656, bandwidth setting value 2658, and bandwidth setting type 2657 are included as elements.

  Each element included in the communication quality information DB 265 is the same as the element of the same name in the communication quality information DB 165 of the bandwidth control server 1. That is, the service identifier 2651, source address 2652, destination address 2673, port number 2654, minimum bandwidth setting type 2655, minimum bandwidth setting value 2656, bandwidth setting value 2658, and bandwidth setting type 2657 are service identifiers in the communication quality information DB 165. 1651, source address 1652, destination address 1673, port number 1654, minimum bandwidth setting type 1655, minimum bandwidth setting value 1656, bandwidth setting value 1658, and bandwidth setting type 1657.

  FIG. 3D is an explanatory diagram illustrating the session information DB 267 according to this embodiment.

  The session information DB 267 is a database that manages information on a communication session that passes through the communication speed-up device 2. The session information DB 267 is a session identifier 2671 that identifies a session, a session source address 2672, a session destination address 2673, a communication type 2673, a transmission The element includes an original port number 2675, a destination port number 2676, an in-buffer data amount 2677 accumulated in a buffer associated with the session, an upper limit bandwidth 2678 of the session, and a minimum bandwidth 2679.

  The content of each element included in the session information DB 267 is the same as the content of the element of the same name in the session information DB 167 of the bandwidth control server 1. That is, the session identifier 2671, the transmission source address 2672, the destination address 2673, the communication type 2675, the transmission source port number 2675, the destination port number 2676, the buffer data amount 2677, the upper limit bandwidth 2678 of the session, and the lowest bandwidth 2679 Corresponds to the session identifier 1671, the source address 1672, the destination address 1673, the communication type 1674, the source port number 1675, the destination port number 1676, the buffer data amount 1677, the upper limit bandwidth 1678 of the session, and the lowest bandwidth 1679 of the information DB 167 To do.

  Next, the overall operation of the bandwidth control system of this embodiment will be described with reference to a sequence diagram.

  FIG. 4A is a sequence diagram illustrating processing in which the communication speed-up device 2 according to the present embodiment registers its own device in the bandwidth control server 1.

  In order for the bandwidth control server 1 to perform bandwidth control processing on the communication speed-up device 2 in the bandwidth control system, the bandwidth control server 1 needs to collect information regarding the communication speed-up device 2 existing in the bandwidth control system. . This can be realized by the communication speed-up device 2 transmitting device information registration to the bandwidth control server 1 (S1-01).

  FIG. 60 is an explanatory diagram illustrating an example of a set of message formats according to the present embodiment.

  FIG. 60A is an explanatory diagram showing PF-01 of the format of a message transmitted in the device information registration of this embodiment.

  The device information registration is a message source address, a message destination address, a packet type (indicating that the message includes device information registration), a device identifier (corresponding to the device identifier 2631), and a device address (corresponding to the device address 2632). , Device bandwidth (corresponding to device bandwidth 2633), and minimum bandwidth limit (corresponding to minimum bandwidth limit 2634). The communication speed-up program 261 stores the values of the device basic information DB 263 in the device information registration PF-01 as the device identifier, device address, device bandwidth, and minimum bandwidth limit amount.

  When the device information registration is received in S1-01, the bandwidth allocation program 161 of the bandwidth control server 1 increases the communication speed by using the device identifier, device address, device bandwidth, and minimum bandwidth limit amount in the message of PF-01. Store in the device information DB 163.

  Next, the bandwidth allocation program 161 searches the communication quality information DB 165 using the device identifier of PF-01, and extracts a line of the communication quality information DB 165 in which the device identifier 1650 corresponds to the device identifier of PF-01. Corresponding communication quality information is a row in which the device identifier of PF-01 and the device identifier 1650 are equal, or a row in which the device identifier 1650 indicates all devices. The extracted lines are managed by the bandwidth allocation program 161 of the bandwidth control server 1 so that there is no contradiction.

  In order to notify the communication speed-up server 2 that has transmitted the device information registration of the communication quality information of the communication speed-up device 2, the bandwidth allocation program 161 of the bandwidth control server 1 communicates the extracted row as the communication quality information. It transmits to the speed-up device 2 (S1-04).

  FIG. 60B is an explanatory diagram showing PF-02 of the message format of the communication quality information transmitted in S1-04 of the present embodiment.

  The communication quality information includes a message source address, a destination address, a packet type (indicating that the message includes communication quality information), and one or more pieces of communication quality information. The communication quality information of PF-02 includes a service identifier (corresponding to service identifier 1651), a transmission source address (corresponding to transmission source address 1652), a destination address (corresponding to destination address 1653), and a port number (corresponding to port number 1654). Minimum bandwidth setting type (corresponding to minimum bandwidth setting type 1655), minimum bandwidth setting value (corresponding to minimum bandwidth setting value 1656), bandwidth setting type (corresponding to bandwidth setting type 1657), and bandwidth setting value (bandwidth setting value) 1658).

  When the communication quality information is received in S1-04, the communication speedup device 2 stores all the communication quality information in the received message in the communication quality information DB 165.

  Communication quality information of the communication speed increasing device 2 in this embodiment is collectively managed by the bandwidth control server 1 in advance. However, communication quality information may be set in advance in each of the communication speed-up devices 2.

  In such a case, the communication quality information is notified from the communication speed-up device 2 to the bandwidth control server 1. FIG. 4B shows an example of processing.

  FIG. 4B is a sequence diagram illustrating processing in which the communication speed-up device 2 registers its own device to the bandwidth control server 1 when the communication speed-up device 2 of this embodiment is preset with communication quality information.

  The communication speed-up device 2 transmits device information registration to the bandwidth control server 1 (S2-01).

  The message format for device information registration is PF-01 in FIG. When the device information registration is received, the bandwidth control server 1 transmits device information registration completion to the communication speed-up device 2 (S2-04).

  FIG. 60C is an explanatory diagram showing PF-03 of the message format for device information registration completion according to the present embodiment.

  The device information registration completion of PF-03 includes a message source address, a destination address, a packet type (indicating that the message notifies device information registration completion), and a response code. The response code represents success or failure of the registration process and indicates success or error.

  When the device information registration completion is received, the communication speed increasing program 261 of the communication speed increasing device 2 transmits the communication quality information registration to the bandwidth control server 1 (S2-07).

  FIG. 60D is an explanatory diagram illustrating PF-04 of the message format for registering communication quality information according to this embodiment.

  The communication quality information registration includes a message source address, a destination address, a packet type (indicating that the message notifies communication quality information registration), a device identifier, and one or more pieces of communication quality information. The configuration of the communication quality information is the same as the item of the same name in the communication quality information (PF-02).

  When the communication quality information registration is received, the bandwidth allocation program 161 of the bandwidth control server 1 stores the set of the device identifier and the communication quality information in the message in the communication quality information DB 165. After storing the communication quality information, the bandwidth allocation program 161 of the bandwidth control server 1 transmits communication quality information registration completion to the communication speed-up device 2 (S2-10).

  The message format of communication quality information registration completion is PF-03 shown in FIG. Items other than the packet type of communication quality information registration completion are the same as those for device information registration completion (S2-04). The packet type in S2-10 stores a value indicating completion of communication quality information registration. The response code includes a value indicating success or failure of registration of communication quality information.

  As a case where registration of communication quality information fails, there is a case where inconsistency occurs in communication quality information. For example, when there is an item of communication quality information for all the communication speed increasing devices 2 in the bandwidth control server 1, the communication speed increasing device 2 may attempt to register an individual setting item that collides with this item. Applicable.

  Next, a process in which the bandwidth control server 1 allocates a bandwidth to the communication speed-up device 2 according to the communication quality information and the actual communication status will be described with reference to the time series diagram of FIG.

  FIG. 5 is a sequence diagram showing the bandwidth allocation processing of the present embodiment.

  The bandwidth control server 1 first starts bandwidth control by collecting information about a session from the communication speed-up devices 2 (2-1 to 2-N) in the bandwidth control system. The communication speed increasing device 2 (2-1 to 2-N) transmits the session information to the bandwidth control server 1 at a constant cycle (S3-01, 04, 07).

  FIG. 60E is an explanatory diagram illustrating PF-05, which is a message format of the session information according to this embodiment.

  The PF-05 session information includes a message source address, a destination address, a packet type (indicating that the message includes session information), a device identifier, and one or more pieces of session information.

  The session information includes a session identifier (corresponding to session identifier 2671) for identifying a session, a transmission source address (corresponding to transmission source address 2672), a destination address (corresponding to destination address 2673), a communication type (corresponding to communication type 2673), A transmission source port number (corresponding to a transmission source port number 2675) and a destination port number (corresponding to a destination port number 2676) are included. These items are extracted from the session information DB 267 by the communication speed increasing program 261 of the communication speed increasing device 2 and stored in the message PF-05.

  When the session information is received, the bandwidth allocation program 161 updates the session information DB 167 using the received session information. When session information is received from all the communication speed-up devices 2 in the bandwidth control system within a predetermined period, the bandwidth allocation program 161 calculates a bandwidth to be allocated to each communication speed-up device 2 in the following procedure.

  First, as procedure 1, the bandwidth allocation program 161 allocates the minimum bandwidth 1679 to each session (S3-10). In step 2, the bandwidth allocation program 161 allocates an upper limit bandwidth 1678 to each session based on the lowest bandwidth 1679 and the device bandwidth 1633 (S3-13).

  Based on the received session information, the bandwidth control server 1 of the present embodiment can ensure the minimum communication quality according to the session by assigning the minimum bandwidth 1679 to each session in S3-10. In addition, since the minimum bandwidth 1679 is allocated based on information regarding all sessions, the occurrence of congestion in each of the communication speed-up devices 2 can be reduced.

  Furthermore, the bandwidth control server 1 of the present embodiment can ensure the communication quality corresponding to each session by allocating the upper limit bandwidth 1678 to each session based on the received session information. Moreover, since the upper limit bandwidth 1678 is allocated based on information regarding all sessions, the occurrence of congestion in each of the communication speed-up devices 2 can be reduced.

  FIG. 6 is a block diagram illustrating an example of a bandwidth control system when performing the bandwidth allocation processing according to the present embodiment.

  In order to specifically describe the processing in S3-10 and S3-13, four communication speed-up devices 2 (2-1 to 2-4), FTP / HTTP servers (terminal / server 3-1) are included in the bandwidth control system. ) And terminals 2, 3, and 4 (terminal / servers 3-2 to 3-4) are shown below.

  In the bandwidth control system shown in FIG. 6, one FTP session SS01 and one HTTP session SS02 are established between the terminal 2 (terminal / server 3-2) and the FTP / HTTP server (terminal / server 3-1). Then, the FTP session SS03 is established between the terminal 3 (terminal / server 3-3) and the FTP / HTTP server (terminal / server 3-1). The terminal 4 (terminal / server 3-4) communicates with the FTP / HTTP server (terminal / server 3-1) by HTTP. In FIG. 6, the bandwidth control server 1 is not shown.

  Regarding the setting method of the band setting value 1658 in the communication quality information DB 165 of the band control server 1, specifically, the method of allocating the remaining band to the service or the like, the first method to the fourth as described above in the present embodiment. There are four methods up to

  In the following, processing for assigning the minimum bandwidth 1679 to the communication speed-up device 2 according to each method from the first method to the fourth method will be described.

  The minimum bandwidth 1679 is calculated based on the minimum bandwidth limit 1634 of the communication speed increasing device information DB 163 and the minimum bandwidth setting value 1656 of the communication quality information DB 165.

  FIG. 7 is an explanatory diagram showing the DB before the lowest bandwidth 1679 is calculated by the service bandwidth designation of this embodiment.

  FIG. 7A is an explanatory diagram showing the communication speed-up device information DB 163 before the lowest bandwidth 1679 is calculated by the service bandwidth designation of this embodiment.

  FIG. 7B is an explanatory diagram showing the communication quality information DB 165 before the lowest bandwidth 1679 is calculated by the service bandwidth designation of this embodiment.

  FIG. 7C is an explanatory diagram showing the session information DB 167 before the lowest bandwidth 1679 is calculated by the service bandwidth designation of this embodiment.

  FIGS. 7A to 7C show an example of a DB held by the bandwidth control server 1 when the minimum bandwidth 1679 is not calculated in the bandwidth control system and communication situation shown in FIG.

  In the communication quality information DB 165 shown in FIG. 7B, the band setting type 1657 and the band setting value 1658 are not described because they do not affect the calculation process of the minimum band 1679. Similarly, the data amount 1677 in the buffer and the upper limit bandwidth 1678 of the session information DB 167 do not affect the calculation processing of the minimum bandwidth 1679, and thus are not described. Since the lowest band 1679 in FIG. 7C is not calculated, it includes a blank or an invalid value.

  In the communication quality information DB 265 shown in FIG. 7B, in each of the communication speed-up devices 2, 5 Mbps is guaranteed as the minimum bandwidth of the HTTP service, 10 Mbps is guaranteed as the minimum bandwidth of the FTP service, and the minimum bandwidth of other sessions As shown, 5 Mbps is guaranteed.

  A value obtained by summing the minimum bandwidths of each service is the minimum bandwidth limit 1634 of each of the communication speed-up devices 2 (2-1 to 2-4) in FIG. 6 indicated by the communication speed-up device information DB 163. Must be preset in the following: Even when there are five or more communication speed-up devices 2 in the bandwidth control system, it is necessary to set the bandwidth limit amount 1634 or less of all the communication speed-up devices 2 provided in the bandwidth control system.

  The session information DB 167 illustrated in FIG. 7C includes two rows indicating one session. When two rows indicate one session, the same values are stored in the source address 1672, the destination address 1673, the source port number 1675, and the destination port number 1676 of the two rows, respectively. Also, one communication type 1673 of the two rows indicates transmission, and the remaining one communication type 1673 of the two rows indicates reception.

  In this embodiment, as the values of the device identifier 1631, the device identifier 1650, and the device identifier 1670, the communication speed increasing device 2-1 is described as “device 1”, and the communication speed increasing device 2-2 is It may be described as “device 2”, the communication speed increasing device 2-3 may be described as “device 3”, and the communication speed increasing device 2-4 may be described as “device 4”.

  FIG. 8 is a flowchart showing a process for calculating the minimum bandwidth 1679 by specifying the service bandwidth according to this embodiment.

  The process shown in FIG. 8 is a process executed in S3-10 shown in FIG. 5 when the minimum band setting type 1655 of the communication quality information DB 165 indicates service band designation.

  In accordance with the communication quality information DB 165 and the session information DB 167 shown in FIGS. 7B and 7C, the bandwidth allocation program 161 of the bandwidth control server 1 assigns the minimum bandwidth 1679 to each session. First, the bandwidth allocation program 161 searches the session information DB 167 and the communication quality information DB 165 to extract a session service established in each of the communication speed increasing devices 2 (F1-04).

  Specifically, the bandwidth allocation program 161 extracts at least one of two rows indicating one session from the source 167 from the transmission source address 1672, the destination address 1673, the communication type 1673, and the destination port number 1676. Then, the bandwidth allocation program 161 identifies the source port number 1675 and the destination port number 1676 of the row indicating one extracted session, and the communication quality matching the identified source port number 1675 or destination port number 1676 The row of the port number 1654 in the information DB 165 is extracted. Then, the bandwidth allocation program 161 extracts the service identifier 1651 in the row of the extracted communication quality information DB 165 as a session service.

  For example, in the session information DB 167 of the session information DB 167, the row in which the session identifier 1671 indicates “SS1-1”, “SS1-2”, “SS2-1”, and “SS2-2” is the communication speed increasing device 2-2. The HTTP service session (port number: 80, HTTP session SS02 shown in FIG. 6) and the FTP service session (port number: 21, FTP session SS01 shown in FIG. 6) are established from the communication speed-up device 2-1. Indicates that For this reason, the bandwidth allocation program 161 extracts an HTTP service and an FTP service as services of sessions established in the communication speed increasing device 2-1 and the communication speed increasing device 2-2 in F1-04.

  After F1-04, the bandwidth allocation program 161 searches the communication quality information DB 165 and sets the minimum bandwidth setting value 1656 of the session established in each of the communication speed increasing devices 2 for each service extracted in F1-04. (F1-07). Specifically, the bandwidth allocation program 161 extracts, for each communication speed-up device 2, the minimum bandwidth setting value 1656 in the row indicated by the service identifier 1651 for the service extracted in F1-04.

  For example, according to the communication quality information DB 165 shown in FIG. 7, in F1-07, the bandwidth allocation program 161 extracts 10 Mbps as the minimum bandwidth setting value 1656 of the FTP service in the communication speed increasing device 2-1, 5 Mbps is extracted as the minimum bandwidth setting value 1656 of the HTTP service in the encryption device 2-1. Then, the communication speed-up device 2-1 needs to guarantee the extracted minimum bandwidth setting value 1656.

  After F1-07, the bandwidth allocation program 161 distributes the extracted minimum bandwidth setting value 1656 for each service fairly among a plurality of sessions of each service type (F1-10). When there is one session for one service, F1-10 is not executed.

  For example, since the communication speed-up device 2-1 illustrated in FIG. 6 has established the FTP session SS01 and the FTP session SS03, the number of FTP sessions in the communication speed-up device 2-1 is two. Therefore, the bandwidth allocation program 161 allocates 5 Mbps (10 Mbps / 2) as the minimum bandwidth 1679 to each of the two FTP sessions of the communication speed increasing device 2-1 in F 1-10. Then, the bandwidth allocation program 161 stores 5 Mbps in the lowest bandwidth 1679 in the row where the session identifier 1671 of the session information DB 167 indicates “SS1-1”.

  The bandwidth allocation program 161 allocates 2.5 Mbps as the minimum bandwidth 1679 to each of the HTTP sessions (HTTP sessions SS02 and SS04) of the communication speed increasing device 2-1. Then, the bandwidth allocation program 161 stores 2.5 Mbps in the lowest bandwidth 1679 in the row where the session identifier 1671 of the session information DB 167 indicates “SS1-2”.

  FIG. 9A shows the minimum bandwidth 1679 calculated for each session of each communication speed increasing device 2 by repeating such processing for each of the communication speed increasing devices 2.

  FIG. 9A is an explanatory diagram showing the lowest bandwidth 1679 calculated by the service bandwidth designation of this embodiment.

  The session information DB 167 illustrated in FIG. 9A indicates the session information DB 167 after F1-10 is executed for all the communication speed increasing devices 2.

  The row in which the session identifier 1671 shown in FIG. 9A indicates “SS1-1” and “SS2-1” is two rows indicating one session, and the row in which the session identifier 1671 indicates “SS1-1” is received. A session indicates a session, and a row in which the session identifier 1671 indicates “SS2-1” indicates a transmission session. Here, the lowest bandwidth 1679 in the row in which the session identifier 1671 shown in FIG. 9A indicates “SS1-1” and the lowest bandwidth 1679 in the row in which the session identifier 1671 indicates “SS2-1” are different.

  As described above, when the minimum bandwidth 1679 of the transmission session and the reception session of one session is assigned by F1-10, the bandwidth allocation program 161 has two bandwidth allocation programs 161 for the purpose of preventing the minimum bandwidth limit 1634 from being exceeded. The smallest lowest bandwidth 1679 among the lowest bandwidths 1679 of the row is determined as the lowest bandwidth 1679 of the session (F1-13). Thereby, the bandwidth allocation program 161 adjusts the minimum bandwidth 1679 calculated by F1-10 according to each of the communication speed increasing devices 2.

  Since the minimum bandwidth 1679 of the row where the session identifier 1671 indicates “SS1-1” is 5 Mbps and the minimum bandwidth of the row where the session identifier 1671 indicates “SS2-1” is 10 Mbps, the bandwidth allocation program 161 The minimum bandwidth 1679 of the FTP session between the speed-up device 2-1 and the communication speed-up device 2-2 is determined to be 5 Mbps. By performing such processing for all combinations of transmission sessions and reception sessions indicating one session indicated by the session information DB 167 of FIG. 9A, the minimum bandwidth 1679 shown in FIG. 9B is set.

  FIG. 9B is an explanatory diagram illustrating a result of adjusting the minimum band 1679 by the service band designation according to the present embodiment.

  The session information DB 167 illustrated in FIG. 9B indicates the result of executing F1-13.

  After F1-13, the bandwidth allocation program 161 ends the process of S3-10 shown in FIG.

  Next, processing for assigning the minimum bandwidth 1679 to the communication speed-up device 2 according to the service band relative designation of the second method will be described. The communication speed-up device information DB 163 and the session information DB 167 before calculating the minimum bandwidth 1679 using the second method are the same as the communication speed-up device information DB 163 in FIG. 7A and the session information DB 167 in FIG. The same. Further, the bandwidth allocation program 161 calculates the minimum bandwidth 1679 in the bandwidth control system shown in FIG.

  FIG. 10 is an explanatory diagram showing the communication quality information DB 165 when the minimum bandwidth allocation process by the relative designation of the service bandwidth according to this embodiment is executed.

  A minimum bandwidth setting type 1655 shown in FIG. 10 indicates service band relative designation. When the service band relative designation is used, the band allocation program 161 allocates the minimum band 1679 of each service based on the relative ratio of the minimum bandwidth limit 1634 of the communication speed-up device 2.

  Also, the minimum bandwidth setting value 1656 shown in FIG. 10 indicates the minimum bandwidth ratio. For this reason, the communication quality information DB 165 shown in FIG. 10 allocates 50% of the minimum bandwidth limit amount 1634 to the minimum bandwidth 1679 of the session of the FTP service in each of the communication speedup devices 2 provided in the bandwidth control system. 30% of the minimum bandwidth limit 1634 is allocated to the minimum bandwidth 1679 of the session, and 20% of the minimum bandwidth limit 1634 is allocated to the minimum bandwidth 1679 of the other sessions.

  FIG. 11 is a flowchart showing a process for calculating the lowest bandwidth 1679 by relative designation of service bandwidth according to this embodiment.

  The process shown in FIG. 11 is a process executed in S3-10 shown in FIG. 5 when the minimum band setting type 1655 of the communication quality information DB 165 indicates service band relative designation.

  First, similarly to F1-04, the bandwidth allocation program 161 searches the session information DB 167 and the communication quality information DB 165, and extracts the service type of the session established in each of the communication speed-up devices 2 (F2-04). ).

  After F2-04, the bandwidth allocation program 161 searches the communication quality information DB 165 to determine the minimum bandwidth ratio of sessions established in each of the communication speed increasing devices 2 for each type of service extracted in F2-04. Are extracted from the minimum bandwidth setting value 1656 (F2-07).

  Note that the sum of the minimum bandwidth ratios (percentage) allocated to each service must be 100% or less in each of the communication speed-up devices 2.

  The bandwidth allocation program 161 searches the communication speed-up device information DB 163 after F2-07, and from each of the minimum bandwidth ratio extracted in F2-07 and the minimum bandwidth limit amount 1634 of each communication speed-up device 2, The minimum bandwidth for each service in the communication speed-up device 2 is calculated (F2-10).

  For example, the bandwidth allocation program 161 specifies, in F2-10, 30 Mbps, which is the minimum bandwidth limit 1634 of the communication speed-up device 2-1, from the communication speed-up device information DB 163. Then, the bandwidth allocation program 161 multiplies 30 Mbps by the minimum bandwidth ratio extracted in F2-07. As a result, the bandwidth of 15 Mbps is allocated to the session of the FTP service in the communication acceleration device 2-1, the bandwidth of 6 Mbps is allocated to the HTTP service in the communication acceleration device 2-1, and the session of other services. Is assigned 6 Mbps.

  After F2-10, the bandwidth allocation program 161 distributes the allocated bandwidth for each service fairly among a plurality of sessions in each service by the same method as F1-10 (F2-13). As a result, a minimum bandwidth 1679 is allocated to each session of each service.

  For example, 7.5 Mbps is distributed to the FTP session of the communication speed-up device 2-1 in a stage where the bandwidth of the other speed-up device 2 is not considered (that is, before execution of F 2-16), and the HTTP session 4.5 Mbps is distributed.

  FIG. 12A shows the result of the same calculation performed on the communication speed increasing devices 2-2 to 2-4.

  FIG. 12A is an explanatory diagram illustrating the minimum bandwidth 1679 calculated by specifying the service bandwidth according to this embodiment.

  The session information DB 167 illustrated in FIG. 12A indicates the session information DB 167 after F2-13 is executed for all the communication speed increasing devices 2.

  After F2-13, the bandwidth allocation program 161 adjusts the minimum bandwidth 1679 as in F1-13 of FIG. 8 (F2-16). After F2-16, the bandwidth allocation program 161 ends S3-10 shown in FIG.

  FIG. 12B is an explanatory diagram illustrating a result of adjusting the minimum band 1679 by the service band relative designation according to the present embodiment.

  FIG. 12B shows the result of the lowest band 1679 after adjustment in F2-16.

  Next, processing for assigning the minimum bandwidth 1679 to the communication speed-up device 2 according to the session bandwidth designation of the third method will be described. The communication speed-up device information DB 163 and the session information DB 167 before calculating the minimum bandwidth 1679 using the third method are the same as the communication speed-up device information DB 163 in FIG. 7A and the session information DB 167 in FIG. The same. Further, the bandwidth allocation program 161 calculates the minimum bandwidth 1679 in the bandwidth control system shown in FIG.

  FIG. 13 is an explanatory diagram showing the communication quality information DB 165 when the allocation of the minimum bandwidth 1679 by the session bandwidth designation of this embodiment is executed.

  The bandwidth allocation program 161 in session bandwidth designation designates a bandwidth that is at least guaranteed for each session. The communication quality information DB 165 shown in FIG. 13 guarantees at least 1.0 Mbps per session for an HTTP session, guarantees a minimum of 2.0 Mbps per session for an FTP session, and 1 session for sessions of other services. It shows that 0.5 Mbps per unit is guaranteed to be reduced.

  FIG. 14 is a flowchart showing a process for calculating the minimum bandwidth 1679 by specifying the session bandwidth according to this embodiment.

  The process illustrated in FIG. 14 is a process executed in S3-10 illustrated in FIG. 5 when the minimum bandwidth setting type 1655 of the communication quality information DB 165 indicates session bandwidth designation.

  When the minimum bandwidth setting type 1655 indicates session bandwidth designation, the bandwidth allocation program 161 first searches the session information DB 167 and extracts services for all sessions (F3-04). The method for extracting a session from the session information DB 167 and the method for extracting the type of service are the same as F1-04.

  After F3-04, the bandwidth allocation program 161 searches the communication quality information DB 165 and extracts the minimum bandwidth 1679 of each session in each communication speedup device 2 according to the type of service extracted in F3-04 ( F3-07). According to the communication quality information DB 165 illustrated in FIG. 13, the bandwidth allocation program 161 extracts 2.0 Mbps per session as the minimum bandwidth 1679 of the FTP session and sets the minimum bandwidth 1679 of the HTTP session per session in F3-07. Extract 1.0 Mbps.

  After F3-07, the bandwidth allocation program 161 calculates the sum of the minimum bandwidth 1679 based on the extracted minimum bandwidth 1679 and the session established in each communication speed-up device 2, and the calculated minimum bandwidth It is determined whether the sum of 1679 exceeds the minimum bandwidth limit 1634 of the communication speed-up device 2 (F3-10).

  According to the bandwidth control system shown in FIG. 6 and the communication quality information DB 165 shown in FIG. 13, two FTP sessions and two HTTP sessions are established in the communication speed-up device 2-1. When the minimum bandwidth 1679 extracted in F3-07 is allocated to these sessions, the total value of the minimum bandwidth 1679 is 6.0 Mbps. This does not exceed the minimum bandwidth limit 1634 (30 Mbps).

  However, when the minimum bandwidth 1679 is assigned in units of sessions, the sum of the minimum bandwidth 1679 increases as the number of sessions increases. For this reason, the sum of the minimum bandwidth 1679 may exceed the minimum bandwidth limit 1634 of the communication speed-up device 2.

  According to the communication quality information DB 165 shown in FIG. 13, the minimum bandwidth 1679 guaranteed for one FTP session is 2 Mbps. According to the communication speed increase device information DB 163 shown in FIG. The minimum bandwidth limit 1634 of −1 is 30 Mbps. Therefore, when 16 or more FTP sessions are established in the communication speed-up device 2-1, the sum of the minimum bandwidths 1679 in the communication speed-up device 2-1 exceeds the minimum bandwidth limit 1634 (30 Mbps).

  There are several possible coping methods when the sum of the minimum bandwidths 1679 exceeds the minimum bandwidth limit 1634 of the communication speed-up device 2, and the bandwidth allocation program 161 in this embodiment uses the coping methods in the processing shown in FIG. Process.

  If the sum of the minimum bandwidths 1679 exceeds the minimum bandwidth limit 1634 of the communication speed-up device 2, the bandwidth allocation program 161 determines in advance that the communication speed-up device 2 distributes the minimum bandwidth 1679 in all sessions. Is set in the bandwidth control server 1 (F3-22). When distribution is set for all sessions, the bandwidth allocation program 161 distributes bandwidth equally among the sessions in communication (F3-31).

  In F3-31, specifically, the bandwidth allocation program 161 divides the minimum bandwidth limit amount 1634 by the ratio of the session bandwidth of the service in order to guarantee the minimum bandwidth 1679 allocated for each service. Then, the bandwidth allocation program 161 distributes the minimum bandwidth 1679 to each session of each service within the range of the minimum bandwidth 1679 assigned to each service.

  For example, in the communication quality information DB 165 shown in FIG. 13, when the sum of the minimum bandwidths 1679 in the communication speed-up device 2-1 exceeds the minimum bandwidth limit 1634, the bandwidth allocation program 161 increases the communication speed in F3-31. The minimum bandwidth limit 1634 (30 Mbps) of the device 2-1 is divided by the bandwidth ratio (2.0: 1.0: 0.5) of each session and assigned to each service. Then, the bandwidth allocation program 161 allocates the minimum bandwidth 1679 fairly in units of sessions in each service.

  In F3-22, when the administrator or the like has not set in advance to distribute the minimum bandwidth 1679 in all sessions, the bandwidth allocation program 161 is a communication high speed in which the sum of the minimum bandwidth 1679 exceeds the minimum bandwidth limit 1634. It is determined whether or not the maximum number of sessions for each service (maximum number of sessions 1659) is set in the bandwidth control server 1 in advance with respect to the control device 2 (F3-25).

  When the upper limit number of sessions for each service is not set in advance, the bandwidth allocation program 161 treats all services without distinction, and all newly established sessions after the minimum bandwidth limit 1634 is exceeded. The method that does not perform the minimum bandwidth guarantee process is used (F3-28).

  If the upper limit number of sessions for each service (maximum number of sessions 1659) is set in advance, the bandwidth allocation program 161 uses a method that does not guarantee the minimum bandwidth 1679 for sessions exceeding the upper limit number (F3-34). .

  FIG. 15 is an explanatory diagram showing the communication quality information DB 165 in which the maximum number of sessions 1659 of this embodiment is set.

  In the communication quality information DB 165, the maximum number of sessions 1659 for each service may be set in advance by the administrator or the like for each of the communication speed increasing devices 2.

  Note that the administrator or the like can also calculate a value obtained by multiplying the maximum number of sessions 1659 in each service by the minimum bandwidth 1679 assigned to each session and totaling all the services to guarantee the maximum minimum bandwidth. The maximum number of sessions 1659 needs to be set so that the minimum bandwidth limit 1634 is not exceeded.

  FIG. 16A is an explanatory diagram showing the lowest bandwidth 1679 calculated by the session bandwidth designation of this embodiment.

  After calculating the minimum bandwidth 1679 for each communication speed-up device 1 in F3-07, F3-28, F3-31, or F3-34, the bandwidth allocation program 161 is the same as F1-13 in FIG. The band 1679 is adjusted (F3-16). After F3-16, the bandwidth allocation program 161 ends the process of S3-10 illustrated in FIG.

  FIG. 16B is an explanatory diagram illustrating a result of adjusting the minimum bandwidth 1679 by specifying the session bandwidth according to this embodiment.

  The session information DB 167 illustrated in FIG. 16B indicates the result of executing F3-16.

  Next, processing for assigning the minimum bandwidth 1679 to the communication speed-up device 2 in accordance with the session bandwidth specific gravity designation of the fourth method will be described. The communication speed-up device information DB 163 and the session information DB 167 before calculating the minimum bandwidth 1679 using the fourth method are the same as the communication speed-up device information DB 163 in FIG. 7A and the session information DB 167 in FIG. The same. Further, the bandwidth allocation program 161 calculates the minimum bandwidth 1679 in the bandwidth control system shown in FIG.

  FIG. 17 is an explanatory diagram showing the communication quality information DB 165 when the allocation of the minimum bandwidth 1679 is performed by specifying the session bandwidth specific gravity according to this embodiment.

  The minimum bandwidth setting type 1655 shown in FIG. 17 indicates session bandwidth specific gravity designation. For this reason, the bandwidth allocation program 161 allocates the minimum bandwidth limit amount 1634 according to the number of sessions. At this time, the bandwidth allocation program 161 calculates the minimum bandwidth 1679 by weighting with the session bandwidth specific gravity for each service. According to the communication quality information DB 165 shown in FIG. 17, as the session bandwidth specific gravity, 4 is determined for the FTP service, 2 is determined for the HTTP service, and 1 is determined for the other services.

  FIG. 18 is a flowchart showing a process of calculating the minimum bandwidth 1679 by specifying the session bandwidth specific gravity according to this embodiment.

  The process shown in FIG. 18 is a process executed in S3-10 shown in FIG. 5 when the minimum bandwidth setting type 1655 of the communication quality information DB 165 indicates session bandwidth specific gravity designation.

  First, similarly to F1-04, the bandwidth allocation program 161 searches the session information DB 167 and the communication quality information DB 165, and extracts the type of service of the session established in each of the communication speed-up devices 2 (F4-04). ).

  After F4-04, the bandwidth allocation program 161 searches the communication quality information DB 165 and sets the minimum bandwidth setting value for each service extracted in F4-04 as the session bandwidth specific gravity of each session in each communication acceleration device 2. 1656 is extracted (F4-07). Thereafter, the bandwidth allocation program 161 calculates the minimum bandwidth 1679 of each session using the minimum bandwidth limit 1634 and the session bandwidth specific gravity (F4-10).

  The session information DB 167 in FIG. 7C indicates that two FTP sessions and two HTTP sessions are established in the communication speed-up device 2-1. Since the session bandwidth specific gravity of the FTP session is set to 4 and the session bandwidth specific gravity of the HTTP session is set to 2, the bandwidth allocation program 161 sets the FTP session to the FTP session in F4-10 according to Equation 1 at the minimum per session. A band 1679 is calculated.

(Minimum bandwidth limit 1634) × (Session band specific gravity of FTP session) / (Sum of session bandwidth specificities of all sessions in each communication speed-up device 2) = 30 × 4 / (4 + 4 + 2 + 2) (Equation 1)
Further, the bandwidth allocation program 161 calculates a minimum bandwidth 1679 per session for the HTTP session according to Equation 2.

(Minimum bandwidth limit 1634) × (Session band specific gravity of HTTP session) / (Sum of session bandwidth specificities of all sessions in each communication acceleration device 2) = 30 × 2 / (4 + 4 + 2 + 2) (Expression 2)
FIG. 19A shows the result of calculating the minimum bandwidth 1679 for all the communication speed increasing devices 2.

  FIG. 19A is an explanatory diagram illustrating the lowest bandwidth 1679 calculated by specifying the session bandwidth specific gravity according to this embodiment.

  The session information DB 167 illustrated in FIG. 19A indicates the session information DB 167 after F4-07 is executed for all the communication speed increasing devices 2.

  After F4-07, the bandwidth allocation program 161 adjusts the minimum bandwidth 1679 as in F1-13 of FIG. 8 (F4-13). After F4-13, the bandwidth allocation program 161 ends S3-10 shown in FIG.

  FIG. 19B is an explanatory diagram illustrating a result of adjusting the minimum bandwidth 1679 by specifying the session bandwidth specific gravity according to the present embodiment.

  The session information DB 167 illustrated in FIG. 19B indicates the result of the minimum bandwidth 1679 after adjustment in F4-13.

  After calculating the lowest bandwidth 1679 assigned to each communication session in S3-10 shown in FIG. 5, the bandwidth allocation program 161 assigns a bandwidth other than the lowest bandwidth 1679 of the communication speed-up device 2 (S3-13). A process for allocating a band other than the minimum band 1679 is called a session band allocation process.

  In the session bandwidth allocation process in S3-13, the bandwidth allocation program 161 refers to the bandwidth setting type 1657 and the bandwidth setting value 1658 of the communication quality information DB 165. The band setting type 1657 indicates service band designation, service band relative designation, session band designation, or session band specific gravity designation, similar to the minimum band setting type 1655. Hereinafter, a method for allocating a session bandwidth in accordance with each bandwidth setting type 1657 will be described.

  FIG. 20 is an explanatory diagram showing the communication quality information DB 165 in the session bandwidth allocation processing by specifying the service bandwidth according to this embodiment.

  First, session bandwidth allocation processing by service bandwidth designation will be described based on the setting example of FIG. 20 and the flowchart of FIG. It should be noted that at the start of the session bandwidth allocation processing by service band designation shown below, the communication speedup device information DB 163 is the same as the communication speedup device information DB 163 shown in FIG. 7A, and the session information DB 167 This is the same as the session information DB 167 shown in 9B.

  Note that before the session bandwidth allocation process is executed, an invalid value is stored in the upper limit bandwidth 1678 of the session information DB 167. In FIG. 20, the minimum bandwidth setting type 1655 and the minimum bandwidth setting value 1656 of the communication quality information DB 165 are not used for the session bandwidth allocation process, and thus are not described.

  In the example of the communication quality information DB 165 shown in FIG. 20, in all the communication speed-up devices 2, a bandwidth of 20 Mbps is allocated to the HTTP session, a bandwidth of 40 Mbps is allocated to the FTP session, and a bandwidth of 10 Mbps is allocated to the sessions of other services. Is assigned a bandwidth setting value 1658.

  FIG. 21 is a flowchart showing session bandwidth allocation processing by service bandwidth designation according to this embodiment.

  The process shown in FIG. 21 is a process executed in S3-13 shown in FIG. 5 when the band setting type 1657 of the communication quality information DB 165 indicates service band designation.

  When the bandwidth setting type 1657 indicates service bandwidth designation, the bandwidth allocation program 161 calculates the difference between the device bandwidth 1633 and the lowest bandwidth 1679 as the remaining bandwidth (F5-04).

  The rows in which the session identifier 1671 of the session information DB 167 shown in FIG. 9B indicates “SS1-1”, “SS1-2”, “SS1-3”, and “SS1-4” are four lines of the communication speed increasing device 2-1. It shows that a minimum bandwidth 1679 of a total of 15 Mbps is allocated to the session. The row in which the device identifier 1631 of the communication speed increasing device information DB 163 is “device 1” indicates that the device bandwidth 1633 of the communication speed increasing device 2-1 is 100 Mbps. For this reason, the bandwidth allocation program 161 calculates 85 Mbps as the remaining bandwidth in F5-04.

  After F5-04, the bandwidth allocation program 161 searches the communication quality information DB 165 and sets the bandwidth setting value 1658 of the service of the session (all sessions indicated by the session information DB 167) in communication with each of the communication speed increasing devices 2. To extract. Then, the bandwidth allocation program 161 allocates the extracted bandwidth setting value 1658 to each service used by each communication speed-up device 2 (F5-07).

  For example, in the session information DB 167 illustrated in FIG. 9A, the row in which the session identifier 1671 indicates “SS1-1”, “SS1-2”, “SS2-1”, and “SS2-2” indicates the communication speedup device 2-1. Shows that two FTP sessions and two HTTP sessions are established. For this reason, the bandwidth allocation program 161 allocates 40 Mbps to the FTP session of the communication speed-up device 2-1 and allocates 20 Mbps to the HTTP service based on the bandwidth setting value 1658 in F 5-07.

  After F5-07, the bandwidth allocation program 161 determines whether there is an unallocated remaining bandwidth (F5-10). Specifically, if the value obtained by subtracting the sum of the bandwidths of the services allocated in F5-07 from the remaining bandwidth calculated in F5-04 is a positive value, the bandwidth allocation program 161 is a remaining unallocated residual. It is determined that a band exists.

  When it is determined that there is no unallocated remaining bandwidth, the bandwidth allocation program 161 executes F5-19. If it is determined that there is an unallocated remaining bandwidth, the bandwidth allocation program 161 executes F5-13.

  In the bandwidth control system shown in FIG. 6, the bandwidth allocation program 161 calculates 25 Mbps {= 85− (40 + 20)} as an unallocated remaining bandwidth related to the communication speedup device 2-1 in F 5-10. Therefore, the bandwidth allocation program 161 determines in F5-10 that there is an unallocated residual bandwidth in the communication speed increasing device 2-1.

  When it is determined that there is an unallocated residual bandwidth, the bandwidth allocation program 161 determines that the unallocated residual bandwidth calculated in F5-10 is the bandwidth allocated to each service in each communication acceleration device 2. It is determined whether or not the sum is below (F5-13). If the unallocated residual bandwidth calculated in F5-10 is equal to or greater than the sum of the bandwidths allocated to each of the services, the bandwidth is further allocated according to the bandwidth setting value 1658 from the unallocated residual bandwidth to each of the services. The band allocation program 161 returns to F5-07.

  If the unallocated remaining bandwidth calculated in F5-10 is less than the total bandwidth allocated to each service, the bandwidth allocation program 161 allocates more bandwidth to each service. Then, division is performed according to the ratio of the bandwidth allocated to each service (F5-16).

  For example, in the above-described example, the total value (60 Mbps) of the bandwidth allocated to the FTP service and the HTTP service of the communication speed increasing device 2-1 is smaller than the unallocated residual bandwidth (25 Mbps). Therefore, the bandwidth allocation program 161 divides the unallocated remaining bandwidth (25 Mbps) by the ratio of the bandwidth setting value 1658 in F5-16. As a result, 25 × 40 / (20 + 40), that is, 16.6 Mbps is allocated to the FTP service in addition to 40 Mbps allocated in F5-07, and 56.6 Mbps is calculated as the total value of the bandwidth allocated to the FTP service. Is done.

  After F5-16 or when it is determined in F5-10 that there is no unallocated residual bandwidth, the bandwidth allocation program 161 calculates a residual bandwidth for each session (F5-19). Specifically, the bandwidth allocation program 161 calculates a value obtained by dividing the bandwidth allocated to each service by the number of sessions of each service as the remaining bandwidth per session.

  After F5-19, the bandwidth allocation program 161 calculates the upper limit bandwidth 1678 using the remaining bandwidth per session and the lowest bandwidth 1679 (F5-22). Specifically, the bandwidth allocation program 161 extracts the minimum bandwidth 1679 of the session information DB 167 indicating each session, and adds the remaining bandwidth per session and the extracted minimum bandwidth 1679. Thereby, the bandwidth allocation program 161 calculates the upper limit bandwidth 1678 for each session. Then, the bandwidth allocation program 161 stores the calculated upper limit bandwidth 1678 in the session information DB 167.

  In the above example, the communication speed increasing device 2-1 has two FTP sessions. Therefore, the bandwidth allocation program 161 calculates the result (28.3 Mbps) obtained by dividing 56.6 Mbps by the number of sessions (2) as the remaining bandwidth allocated to one FTP session in F5-19.

  In FIG. 9B, the row in which the session identifier 1671 indicates “SS1-1” indicates that 5 Mbps is assigned as the minimum bandwidth 1679 to the FTP session of the communication speed increasing device 2-1. Therefore, the bandwidth allocation program 161 calculates 33.3 Mbps (= 28.3 + 5) as the upper limit bandwidth 1678 that is finally assigned to one FTP session.

  FIG. 22A is an explanatory diagram showing the upper limit bandwidth 1678 calculated by the service bandwidth designation of this embodiment.

  FIG. 22A shows the session information DB 167 after F5-22 has been executed. The session information DB 167 illustrated in FIG. 22A includes a session speed-up device 2-3 (device identifier 1670 is “device 3”) and a communication speed-up device 2-4 (device identifier 1670 is “device 4”). Indicates that only one has been established. Therefore, the bandwidth allocated to each of the communication speed-up device 2-3 and the communication speed-up device 2-4 is allocated to one session of each of the communication speed-up device 2-3 and the communication speed-up device 2-4. It is done.

  After F5-22, in the session information DB 167, when different upper limit bands 1678 are assigned to the transmission session and the reception session of one session, the bandwidth allocation program 161 sets the two upper limit bands 1678 for the purpose of preventing congestion. The smaller upper limit band 1678 is determined as the upper limit band 1678 of the session. As a result, the bandwidth allocation program 161 adjusts the upper limit bandwidth 1678 (F5-25).

  The bandwidth allocation program 161 executes the process indicated by F5-25 for all the sessions indicated by the session information DB 167. After executing F5-25, the bandwidth allocation program 161 ends S3-13 shown in FIG.

  For example, in FIG. 22A, the lines in which the session identifier 1671 indicates “SS1-1” and “SS2-1” indicate that the source address 1672, the destination address 1673, the source port number 1675, and the destination port number 1676 are the same value. Therefore, a reception session and a transmission session of one session are shown. Here, the upper limit bandwidth 1678 of the row where the session identifier 1671 indicates “SS1-1” is 33.3 Mbps, and the upper limit bandwidth 1678 of the row where the session identifier 1671 indicates “SS2-1” is 66.6 Mbps. Therefore, in F5-25, the bandwidth allocation program 161 is the same as the upper limit bandwidth 1678 of the row where the session identifier 1671 indicates “SS2-1” and the upper limit bandwidth 1678 of the row where the session identifier 1671 indicates “SS1-1”. By setting the value (33.3 Mbps), the upper limit bandwidth 1678 of the session is adjusted.

  FIG. 22B is an explanatory diagram illustrating a result of session bandwidth allocation processing by service bandwidth designation according to this embodiment.

  FIG. 22B shows the session information DB 167 after the processing shown in F5-25 is executed.

  Next, session bandwidth allocation processing by relative designation of service bandwidth will be described with reference to FIGS. Note that the communication speed-up device information DB 163 at the start of the session bandwidth allocation processing by the service band relative designation shown below is the same as the communication speed-up device information DB 163 shown in FIG. 7A, and the session information DB 167 This is the same as the session information DB 167 shown in 12B.

  FIG. 23 is an explanatory diagram showing the communication quality information DB 165 in the session bandwidth allocation processing by relative designation of service bandwidth according to the present embodiment.

  A band setting type 1657 shown in FIG. 23 indicates a service band relative designation, and a band setting value 1658 indicates a band ratio for each service in each of the communication speed-up devices 2.

  FIG. 24 is a flowchart showing session bandwidth allocation processing by service bandwidth relative designation according to the present embodiment.

  The process illustrated in FIG. 24 is a process executed in S3-13 illustrated in FIG. 5 when the band setting type 1657 of the communication quality information DB 165 indicates relative service band designation.

  First, the bandwidth allocation program 161 calculates the remaining bandwidth from the difference between the device bandwidth 1633 and the lowest bandwidth 1679 as in F5-04 (F6-04). The row in which “device 1” is stored in the device identifier 1670 of the session information DB 167 in FIG. 12B indicates that the communication speed-up device 2-1 has a minimum bandwidth of 24 Mbps (= 7.5 + 4.5 + 7.5 + 4.5). As a result, the bandwidth of 76 Mbps (= 100-24) is the remaining bandwidth of the communication speed-up device 2-1.

  After calculating the remaining bandwidth in F6-04, the bandwidth allocation program 161 searches the bandwidth setting value 1658 of the communication quality information DB 165 and determines the bandwidth ratio of the service corresponding to the session in communication in each communication speedup device 2. Extract (F6-07).

  After F6-07, the bandwidth allocation program 161 divides the remaining bandwidth by the extracted bandwidth ratio, thereby allocating bandwidth to the respective services of the session in each communication speed-up device 2 (F6-10).

  The communication quality information DB 165 of FIG. 23 indicates that 30% of the remaining bandwidth is allocated to the HTTP service and 50% of the remaining bandwidth is allocated to the FTP service. Further, the session information DB 167 in FIG. 12B indicates that there is no other service in the communication speed increasing device 2-1.

  For this reason, the remaining bandwidth in the communication speed-up device 2-1 is allocated to the HTTP service and the FTP service at a bandwidth ratio of 3: 5. In F6-10, the bandwidth allocation program 161 allocates 28.5 Mbps as the remaining bandwidth to the HTTP service of the communication speed increasing device 2-1, and allocates 47.5 Mbps as the remaining bandwidth of the FTP service.

  After distributing the remaining bandwidth to each service in F6-10, the bandwidth allocation program 161 further allocates the remaining bandwidth distributed to each service in units of sessions (F6-13). Then, the bandwidth allocation program 161 adds the minimum bandwidth 1679 to the remaining bandwidth of the session bandwidth calculated in F6-13, and stores the added result in the upper limit bandwidth 1678 (F6-16).

  FIG. 25A is an explanatory diagram showing an upper limit band 1678 calculated by service band relative designation according to the present embodiment.

  FIG. 25A shows the session information DB 167 after F6-16 is executed. The bandwidth allocation program 161 adjusts the upper limit bandwidth 1678 after F6-16, similarly to F5-25 (F6-19).

  The bandwidth allocation program 161 executes the process indicated by F6-16 for all the sessions indicated by the session information DB 167. After executing F6-16, the bandwidth allocation program 161 ends S3-13 shown in FIG.

  FIG. 25B is an explanatory diagram illustrating a result of session bandwidth allocation processing by service band relative designation according to the present embodiment.

  The session information DB 167 in FIG. 25B is the session information DB 167 after the processing shown in F6-19 is executed.

  Next, session bandwidth allocation processing by session bandwidth designation will be described with reference to FIGS. Note that the communication speed-up device information DB 163 at the start of the session bandwidth assignment process by specifying the session bandwidth shown below is the same as the communication speed-up device information DB 163 shown in FIG. 7A, and the session information DB 167 is the same as FIG. This is the same as the session information DB 167 shown in FIG.

  FIG. 26 is an explanatory diagram illustrating the communication quality information DB 165 in the session bandwidth allocation processing by specifying the session bandwidth according to this embodiment.

  A band setting type 1657 shown in FIG. 26 indicates session band designation, and a band setting value 1658 indicates a band allocated for each session.

  FIG. 27 is a flowchart showing session bandwidth allocation processing by session bandwidth designation according to this embodiment.

  The process illustrated in FIG. 27 is a process executed in S3-13 illustrated in FIG. 5 when the band setting type 1657 of the communication quality information DB 165 indicates session band designation.

  First, the bandwidth allocation program 161 calculates the remaining bandwidth from the difference between the device bandwidth 1633 and the lowest bandwidth 1679 as in F5-04 (F7-04). The session information DB 167 of FIG. 16B is assigned with a bandwidth of 6 Mbps as the minimum bandwidth for each session in the communication speed-up device 2-1 (the row of the device identifier 1670 is “device 1”). The band indicates the remaining band of the communication speed increasing device 2-1.

  After calculating the remaining bandwidth in F7-04, the bandwidth allocation program 161 searches the session information DB 167 and the communication quality information DB 165 to extract a service corresponding to the session in communication (F7-07). Then, the bandwidth allocation program 161 extracts the bandwidth corresponding to each session from the bandwidth setting value 1658 in the row of the communication quality information DB 165 corresponding to the extracted service (F7-10).

  After F7-10, the bandwidth allocation program 161 calculates the total value of the extracted bandwidths of all sessions in each communication speed-up device 2 in the remaining bandwidth (F7-04 of each communication speed-up device 2). It is determined whether or not the remaining bandwidth is exceeded (F7-13).

  If the total bandwidth does not exceed the remaining bandwidth of the communication speedup device 2, the bandwidth allocation program 161 assigns the bandwidth extracted in F7-10 to each session, and assigns the assigned bandwidth to each communication speedup device 2. Is subtracted from the remaining bandwidth (F7-16). After F7-16, the bandwidth allocation program 161 returns to F7-10 and tries to allocate bandwidth to each session again.

  When the total value of the session bandwidth exceeds the remaining bandwidth, the bandwidth allocation program 161 distributes the remaining bandwidth by the ratio of the session bandwidth of each service, and then divides the bandwidth fairly for each session (F7-28).

  The session information DB 167 illustrated in FIG. 12B indicates that two FTP sessions and two HTTP sessions are established in the communication speedup device 2-1. Then, the communication quality information DB 165 shown in FIG. 26 indicates that the bandwidths to be allocated to the FTP session and the HTTP session are 2.0 Mbps and 1.0 Mbps, respectively.

  Therefore, every time the processing of F7-16 is performed, the bandwidth allocation program 161 allocates the remaining bandwidth of 6 Mbps to each service session as a session bandwidth. When such F7-16 allocation processing is repeated 15 times, the remaining bandwidth (4 Mbps) falls below the total session bandwidth (6 Mbps).

  In this case, the remaining bandwidth is 4 Mbps. The bandwidth allocation program 161 allocates this remaining bandwidth to each service at a session bandwidth ratio (2: 1) (assigns 8/3 Mbps to the FTP service and 4/3 Mbps to the HTTP service), and then in each service. Distributes bandwidth by session. For this reason, in F7-28, 31.3 (≈1 / 2 × (15 × 4 + 8/3)) Mbps is allocated to the FTP session of the communication speed-up device 2-1, and the communication speed-up device 2-1. 15.6 (≈1 / 2 × (15 × 2 + 4/3) Mbps) is allocated to the HTTP session.

  After calculating the bandwidth per session in F7-28, the bandwidth allocation program 161 adds the remaining bandwidth allocated to each session up to F7-28 and the minimum bandwidth 1679 of each session, and the added result is The upper limit bandwidth 1678 for each session is stored in the session information DB 167 (F7-19).

  FIG. 28A is an explanatory diagram showing the upper limit bandwidth 1678 calculated by specifying the session bandwidth according to this embodiment.

  FIG. 28A shows the session information DB 167 after F7-19 is executed. The bandwidth allocation program 161 adjusts the upper limit bandwidth 1678 after F7-19, similarly to F5-25 (F7-22).

  The bandwidth allocation program 161 executes the process indicated by F7-22 for all the sessions indicated by the session information DB 167. After executing F7-22, the bandwidth allocation program 161 ends S3-13 shown in FIG.

  FIG. 28B is an explanatory diagram illustrating a result of session bandwidth allocation processing by session bandwidth designation according to this embodiment.

  The session information DB 167 in FIG. 28B is the session information DB 167 after the process shown in F7-22 is executed.

  Next, session bandwidth allocation processing by specifying session bandwidth specific gravity will be described with reference to FIGS. 29 and 30. FIG. Note that the communication speed-up device information DB 163 at the start of the session bandwidth allocation processing by specifying the session bandwidth specific gravity shown below is the same as the communication speed-up device information DB 163 shown in FIG. 7A, and the session information DB 167 This is the same as the session information DB 167 shown in 19B.

  FIG. 29 is an explanatory diagram showing the communication quality information DB 165 in the session bandwidth allocation processing by specifying the session bandwidth specific gravity according to this embodiment.

  A band setting type 1657 shown in FIG. 29 indicates session band specific gravity designation, and a band setting value 1658 indicates a band allocated for each session. The bandwidth allocation program 161 for specifying the session bandwidth specific gravity allocates the remaining bandwidth of the apparatus according to the number of sessions. At that time, the bandwidth allocation program 161 weights the bandwidth allocated for each service by the session bandwidth specific gravity (corresponding to the bandwidth setting value 1658).

  The communication quality information DB 165 shown in FIG. 29 indicates that the session bandwidth specific gravity of the FTP service is 4, the session bandwidth specific gravity of the HTTP service is 2, and the other services are 1.

  FIG. 30 is a flowchart showing the session bandwidth allocation processing by specifying the session bandwidth specific gravity according to this embodiment.

  The process shown in FIG. 30 is a process executed in S3-13 shown in FIG. 5 when the band setting type 1657 of the communication quality information DB 165 indicates session band designation.

  First, the bandwidth allocation program 161 calculates the remaining bandwidth from the difference between the device bandwidth 1633 and the lowest bandwidth 1679 as in F5-04 (F8-04). The session information DB 167 of FIG. 19B is assigned to each session as a minimum bandwidth of 30 Mbps in the communication speedup device 2-1 (the row of the device identifier 1670 is “device 1”). As a result, the bandwidth of 70 Mbps is It shows that it is the remaining bandwidth of the communication speed-up device 2-1.

  After calculating the remaining bandwidth in F8-04, the bandwidth allocation program 161 searches the session information DB 167 and the communication quality information DB 165 in the same manner as F7-07, and extracts the service corresponding to the session in communication (F8- 07). After F8-07, the bandwidth allocation program 161 and the bandwidth allocation program 161 extract the band specific gravity corresponding to each session from the bandwidth setting value 1658 of the line of the communication quality information DB 165 corresponding to the extracted service. (F8-10).

  After F8-10, the bandwidth allocation program 161 calculates the session bandwidth using the bandwidth specific gravity in the same manner as the lowest bandwidth calculation method using bandwidth specific gravity (F4-10 shown in FIG. 18) (F8-13). . For example, the bandwidth allocation program 161 calculates a session bandwidth per FTP session by using an equation in which (the minimum bandwidth limit 1634) in Equation (1) is replaced with the remaining bandwidth calculated in F8-04. .

  After F8-13, the bandwidth allocation program 161 stores the added result as the upper limit bandwidth 1678 in the session information DB 167 (F8-16). The bandwidth allocation program 161 executes F8-13 and F8-16 for all sessions.

  FIG. 31A is an explanatory diagram showing the upper limit band 1678 calculated by specifying the session band specific gravity according to the present embodiment.

  FIG. 31A shows the session information DB 167 after F8-16 is executed. The band allocation program 161 adjusts the upper limit band 1678 after F8-16, similarly to F5025 (F8-19).

  The bandwidth allocation program 161 executes the process indicated by F8-19 for all the sessions indicated by the session information DB 167. After executing F8-19, the bandwidth allocation program 161 ends S3-13 shown in FIG.

  FIG. 31B is an explanatory diagram illustrating a result of the session bandwidth allocation process by specifying the session bandwidth specific gravity according to the present embodiment.

  The session information DB 167 in FIG. 31B is the session information DB 167 after the processing shown in F8-19 is executed.

  In the conventional minimum bandwidth allocation processing and session bandwidth allocation so far, a method has been adopted in which the bandwidth is calculated mainly for each service and then the bandwidth is fairly distributed to each session within the service. However, in actual communication, the bandwidth required for each communication session is not uniform.

  For example, consider the system configuration shown in FIG.

  FIG. 32 is a block diagram illustrating an example of a bandwidth control system when different bandwidths are allocated for each session according to the present embodiment.

  In FIG. 32, the terminal / server 3-2 downloads a file from the FTP / HTTP server (terminal / server 3-1) via the communication speed-up devices 2-2 and 2-1, and the terminal / server 3-3 indicates that a file is downloaded from the FTP / HTTP server via the communication speed-up devices 2-3 and 2-1.

  When the size of the file downloaded by the terminal / server 3-2 and the size of the file downloaded by the terminal / server 3-3 are greatly different, the bandwidth allocation program 161 allocates different bandwidths to the respective FTP sessions, and the communication speed Need to be optimized.

  On the other hand, the bandwidth allocation program 161 holds the in-buffer data amount 1677 as an item of the session information DB 167. For this reason, the bandwidth allocation program 161 can more efficiently distribute the bandwidth by reflecting the data amount 1677 in the buffer in the bandwidth allocated to the session.

  FIG. 33 is an explanatory diagram illustrating the session information DB 167 that holds the data amount in the buffer according to this embodiment.

  FIG. 33 shows the session information DB 167 when the bandwidth is allocated according to the size of the downloaded file in the bandwidth control system shown in FIG. In the example of processing shown below, the communication speedup device information DB 163 is the same as the communication speedup device information DB 163 shown in FIG.

  The communication quality information DB 165 is the same as the communication quality information DB 165 shown in FIG. Specifically, the minimum bandwidth setting type 1655 of the communication quality information DB 165 indicates service bandwidth relative, and the ratio of bandwidth allocated to the FTP service is 50% of the entire bandwidth.

  The data amount 1677 in the buffer in the session information DB 167 is stored in the line indicating the transmission session, and is not stored in the line indicating the reception session. The session information DB 167 in FIG. 33 includes an FTP session (established from the communication speed-up device 2-1 (device identifier 1670 is “device 1”) to the communication speed-up device 2-2 (device identifier 1670 is “device 2”). It indicates that 90 MB of data is held in the buffer for the session identifier 1671 of “SS1-5”).

  The session information DB 167 of FIG. 33 is an FTP established from the communication speed-up device 2-1 (device identifier 1670 is “device 1”) to the communication speed-up device 2-3 (device identifier 1670 is “device 3”). The buffer for the session (session identifier 1671 is “SS1-6”) indicates that 10 MB of data is held.

  Further, by the service ratio indicated by the bandwidth setting value 1658, the minimum bandwidth limit 1634, and the processing indicated by F2-10 in FIG. 11, the minimum bandwidth 1679 of 15 Mbps is provided for the FTP service of the session of the communication acceleration device 2-1. Is assigned. When the bandwidth allocation program 161 distributes the minimum bandwidth 1679 for each session according to the ratio of the buffer data amount 1677, the FTP session (SS1-5) is 13.5 Mbps (= 15 × 90 / (90 + 10)) The minimum bandwidth 1679 of 1.5 Mbps (= 15 × 10 / (90 + 10)) is allocated to the FTP session (SS1-6).

  The bandwidth allocation program 161 can also apply proportional distribution similar to that described above when allocating the upper limit bandwidth 1678. In application, a method of proportionally allocating the bandwidth based on the data amount 1677 in the buffer to both the minimum bandwidth 1679 and the upper limit bandwidth 1678, or a method of performing proportional distribution only to one of the two bandwidths can be considered. When the buffer data amount 1677 is used for bandwidth allocation, the communication speed-up device 2 needs to notify the bandwidth control server 1 of the buffer data amount 1677 as session information.

  FIG. 62 is an explanatory diagram showing an example of a third set of message formats in the present embodiment.

  FIG. 62C is an explanatory diagram illustrating a message format including the data amount in the buffer according to this embodiment.

  FIG. 62 (c) shows a message format (PF-12) in which an area for storing the data amount in the buffer is added to PF-05 shown in FIG. 60 (e). The PF-12 is transmitted from the communication speed-up device 2 to the bandwidth control server 1 in S3-01, 04, or 07 shown in FIG.

  By using the data amount in the buffer, the bandwidth allocation program 161 of the present embodiment can allocate a bandwidth according to the session status.

  When the minimum bandwidth 1679 and the upper limit bandwidth 1678 corresponding to all communication sessions are allocated by any of the four methods described above, the bandwidth allocation program 161 assigns the allocated minimum bandwidth 1679 and upper limit bandwidth 1678 to each communication high speed. Notification to the computer 2. This is performed by the band information notification (S3-16 to S3-22) in FIG.

  FIG. 61 is an explanatory diagram illustrating a second example of the message format according to this embodiment.

  FIG. 61A is an explanatory diagram showing a message format in the band information according to the present embodiment.

  The PF-06 in FIG. 61A includes a message source address (corresponding to the source address 1672), a destination address (corresponding to the destination address 1673), a packet type (a value indicating bandwidth information), and one or more. Includes bandwidth information. The band information indicates a band allocation result for each session, and includes a session identifier (corresponding to the session identifier 1671), an upper limit band (corresponding to the upper limit band 1678), and a minimum band (corresponding to the minimum band 1679).

  When the bandwidth information is received, the communication speed increasing device 2 performs the communication speed increasing processing within the range of the upper limit bandwidth and the minimum bandwidth indicated by the notified bandwidth information (S3-22).

  The above-described bandwidth allocation is performed within the range of the device bandwidth of the communication speed increasing device 2. The device bandwidth is generally determined in view of the contract bandwidth between the base 5 and the network 4 connecting the outside. For example, in the bandwidth control system shown in FIG. 6 described above, the communication speed increase devices 2-1 to 2-4 are installed at the bases 5-1 to 5-4, respectively, as in the system shown in FIG. 5 is connected to the network 4 through a line having a bandwidth of 100 Mbps. However, in actual system operation, it is necessary to optimize the bandwidth allocation by dividing the resources of one communication speed-up device 2 into a plurality of resources.

  FIG. 34 is a block diagram showing a bandwidth control system in which a plurality of departments 6 are included in the base 5 of the present embodiment.

  FIG. 34 shows a bandwidth control system when the base 5-1 includes a department 6-1 and a department 6-2, and one communication speed-up device 2 accommodates two departments 6. For example, when the base 5-1 is one building and two companies exist in the building, or when two departments 6 exist in one company, the configuration is shown in FIG. In order to appropriately allocate the bandwidth to each department 6, it is necessary for both the communication speed-up device 2 and the bandwidth control server 1 to manage information on the department 6-1 and the department 6-2.

  FIG. 35 is an explanatory diagram showing the communication speed-up device 2 that holds information related to the department 6 of this embodiment.

  FIG. 35A is a block diagram showing the configuration of the communication speed-up device 2 that holds information related to the department 6 of this embodiment.

  In addition to the processing unit and DB of the communication speedup device 2 shown in FIG. 3, the communication speedup device 2 shown in FIG. 35 has a segment information DB 264. The segment information DB 264 is a DB including information on each of the departments 6.

  FIG. 35B is an explanatory diagram illustrating the segment information DB 264 included in the communication speed-up device 2 according to the present embodiment.

  The segment information DB 264 includes a segment identifier 2641, a segment start address 2642, a segment end address 2643, and a segment minimum bandwidth limit 2644. The segment identifier 2641 is an identifier that uniquely indicates each of the plurality of departments 6 included in the base 5. Hereinafter, a set of addresses indicating one department 6 is referred to as a segment.

  A segment start address 2642 and a segment end address 2643 indicate a range of segment addresses. The communication acceleration program 261 recognizes a session including an address within the segment range as a destination address or a transmission source address as a session belonging to the segment (that is, the department 6 corresponding to the segment).

  The segment minimum bandwidth limit amount 2644 is a value used when calculating the minimum bandwidth allocated to each segment. The sum of the segment minimum bandwidth limits 2644 of all the segments needs to be less than or equal to the minimum bandwidth limit 2634 of the communication speed-up device 2.

  FIG. 36 is an explanatory diagram showing the bandwidth control server 1 that holds information related to the department 6 of this embodiment.

  FIG. 36A is a block diagram illustrating a configuration of the bandwidth control server 1 that holds information related to the department 6 according to the present embodiment.

  The bandwidth control server 1 includes a segment information DB 164 in addition to the processing unit and DB shown in FIG. The segment information DB 164 is a DB including information related to the department 6 included in the bandwidth control system.

  FIG. 36B is an explanatory diagram illustrating the segment information DB 164 included in the bandwidth control server 1 according to the present embodiment.

  The segment information DB 164 includes a device identifier 1640, a segment identifier 1641, a segment start address 1642, a segment end address 1643, and a segment minimum bandwidth limit 1644. The device identifier 1640 is an identifier that uniquely indicates the communication speed increasing device 2, and uniquely indicates the base 5 in the bandwidth control system illustrated in FIG.

  The segment identifier 1641, the segment start address 1642, the segment end address 1643, and the segment minimum bandwidth limit 1644 are the segment identifier 2641, the segment start address 2642, the segment end address 2643, and the segment minimum bandwidth limit in the communication speed-up device 2. It corresponds to the quantity 2644.

  When the bandwidth control server 1 holds the segment information 164, the communication quality information DB 165 and the session information DB 167 hold values corresponding to the segment identifier 1641. The communication quality information DB 165 and the session information DB 167 hold information in segment units.

  When the communication speed-up device 2 holds information on a plurality of segments, the communication speed-up device 2 needs to register the segment information DB 264 in the bandwidth control server 1. The communication speed-up program 261 registers information included in the segment information DB 264 and information related to the segments in the bandwidth control server 1 in each sequence illustrated in FIGS. 4A and 4B. At that time, the segment identifier is included in the message notified from the communication speed-up device 2 to the bandwidth control server 1.

  Information corresponding to the segment information DB 264 is transmitted to the bandwidth control server 1 in S1-01 in FIG. 4A or S2-01 in FIG. 4B.

  FIG. 61 (b) is an explanatory diagram showing a message format including the segment identifier of this embodiment.

  For example, the communication speed-up program 261 transmits the message PF-07 shown in FIG. 61B to the bandwidth control server 1 in S1-04 for registering communication quality information shown in FIG. PF-07 is a format in which a segment identifier is added to PF-02 shown in FIG.

  FIG. 61C is an explanatory diagram showing a message format including a device identifier and a segment identifier according to the present embodiment.

  The communication speed-up program 261 transmits, for example, a PF-08 message shown in FIG. 61 (c) to the bandwidth control server 1 in S2-07 for registering communication quality information shown in FIG. 4B.

  FIG. 37 is a sequence diagram illustrating a process for allocating a band for each department 6 according to the present embodiment.

  FIG. 37 shows the bandwidth allocation processing when the bandwidth allocated to the communication speed-up device 2 using segments is divided into department units. The bandwidth control server 1 first collects information on the session from the communication speed-up device 2 as in S3-01, 04, 07 shown in FIG. 5 (S4-01, 04, 07). The message format in S4-01, 04, 07 in FIG. 37 is shown in PF-09 in FIG. 61 (d).

  FIG. 61D is an explanatory diagram showing a message format for transmitting session information including the segment identifier of this embodiment.

  PF-09 in FIG. 61 (d) is a message format including a segment identifier in the session information of PF-05.

  When the bandwidth control server 1 holds the segment information DB 164, the session information DB 167 and the communication quality information DB 165 hold segment identifiers.

  After the session information is transmitted in S4-01, 04, 07, etc., the bandwidth allocation program 161 allocates the minimum bandwidth 1679 for each segment (S4-10). Specifically, in the process shown in FIG. 8, FIG. 11, FIG. 14, or FIG. 18, the process performed for each communication speed-up device 2 is performed for each segment. The bandwidth allocation program 161 executes processing for the communication speed-up device 2 that is not connected to a plurality of departments 6 as processing for one segment.

  At this time, in the process (F2-10, F3-10, F4-10, etc.) for acquiring the minimum bandwidth limit 1634, the bandwidth allocation program 161 acquires the segment minimum bandwidth limit 1644.

  Taking the system configuration of FIG. 34 as an example, the communication speed-up device 2-1 is connected to two segments of a department 6-1 and a department 6-2. When allocating the minimum bandwidth 1679 to the session belonging to the department 6-1, the bandwidth allocation program 161 refers to the segment information DB 164, acquires the segment minimum bandwidth limit 1644 corresponding to the department 6-1, and obtains the department 6-1. The minimum bandwidth 1679 is allocated within the range of the segment minimum bandwidth limit amount 1644.

  The bandwidth allocation program 161 similarly allocates the minimum bandwidth 1679 to the department 6-2. Since the other communication speed-up devices 2 do not have segments, the minimum bandwidth allocation processing is performed for each device as usual.

  In S4-10, by allocating the minimum bandwidth using the segment minimum bandwidth limit amount 1644 determined for each segment, the communication speed-up device 2 establishes sessions with the terminals / servers 3 of a plurality of segments. A minimum bandwidth 1679 can be allocated so that the session is not congested.

  After S4-10, the bandwidth allocation program 161 calculates a remaining bandwidth, and calculates a final session bandwidth (upper limit bandwidth 1678) based on the calculated remaining bandwidth (S4-13). There are two possible methods of allocating the remaining bandwidth when a plurality of segments are connected to the communication speed-up device 2.

  The first method is a method in which the remaining bandwidth is distributed to each segment at a ratio of the segment minimum bandwidth limit 1644, and the remaining bandwidth that is closed within the segment is assigned. In this method, the bandwidth allocation program 161 regards the segment as an independent virtual communication speed-up device 2.

  The second method is a method that is performed in units of two communication speed increasing devices without considering a segment in the allocation of the remaining bandwidth. In the second method, the remaining bandwidth is allocated to each session according to the actual session distribution.

  Taking the system configuration of FIG. 34 as an example, if the number of sessions in the department 6-1 is much larger than the number of sessions in the department 6-2, the bandwidth allocation program 161 uses the first method for communication. Rather than allocating the remaining bandwidth in units of two speed-up devices, using the second method, allocating the remaining bandwidth to the department 6-1 session allocates more bandwidth to the department 6-1 with more sessions. Can do.

  After assigning the minimum bandwidth 1679 in F4-10 and calculating the upper limit bandwidth 1678 in F4-13, the bandwidth allocation program 161 transmits the bandwidth information to all the communication speed-up devices 2 (S4-16, 19, 22). .

  FIG. 62A is an explanatory diagram showing a message format including band information allocated to the segment of this embodiment.

  PF-10 shown in FIG. 62A is a message format of band information, and is a message format in which a segment identifier is added to the band information item of PF-06. When the communication speed-up device 2 is not connected to a segment, the segment identifier is blank.

  When there is only one communication speed-up device 2 at one site 5, the device band 1633 is freely set within a range not exceeding the band of the site 5. However, when there are a plurality of communication speed-up devices 2 at one base 5, it is necessary to appropriately manage the plurality of communication speed-up devices 2 in order to avoid adversely affecting each other's communication.

  FIG. 38 is a block diagram showing a bandwidth control system in which a plurality of communication speed-up devices 2 are included in the base 5 of the present embodiment.

  The following two cases can be considered as an example in which a plurality of communication speed-up devices 2 exist at one base 5. In the first case, as shown in FIG. 38, a plurality of departments 6-1 and departments 6-2 exist at the base 5-1, and the communication speed-up device 2-11 and the communication are established in each department 6. This is a case where the speed-up device 2-12 is installed.

  In another case, as shown in the base 5-2 in FIG. 38, the miniaturized communication speed-up device 2 can be used by a method such as Universal Serial Bus (USB) or Peripheral Components Interconnect bus (PCI). This is the case where the terminal / server 3 is installed.

  As in such a case, when a plurality of communication speed-up devices 2 exist at one base 5, the bandwidth control server 1 manages the communication speed-up devices 2 in groups.

  FIG. 39 is an explanatory diagram showing the bandwidth control server 1 having the device group management function of this embodiment.

  FIG. 39A is a block diagram showing the configuration of the bandwidth control server 1 having the device group management function of this embodiment.

  The bandwidth control server 1 in FIG. 39 includes a processing unit and DB included in the bandwidth control server 1 in FIG. 36 and a device group information DB 162. The device group information DB 162 indicates a group to which each of the communication speed increasing devices 2 belongs.

  FIG. 39B is an explanatory diagram illustrating the device group information DB 162 according to this embodiment.

  The device group information DB 162 includes a device group identifier 1620, a device group type 1621, a group bandwidth 1622, a group minimum bandwidth limit 1623, and one or more pieces of device information 1624 (1624-1 to 1624-N). The device group identifier 1620 is an identifier that uniquely indicates a group included in the bandwidth control system.

  The device group type 1621 designates a band distribution method for the group. There are two possible bandwidth distribution methods for groups. For example, if a 100 Mbps line accommodates 10 communication speed-up devices 2, each communication speed-up device 2 can be divided into 10 Mbps by dividing the 100 Mbps line equally into the communication speed-up devices 2 in advance. Is assigned. Such a method is called static distribution.

  On the other hand, no bandwidth is allocated in advance, and a bandwidth of 100 Mbps is allocated according to the state of the communication speed-up device 2 in which a communication session exists. Such a method is called dynamic distribution.

  The device group type 1621 of this embodiment indicates a band allocation method for a group by specifying static distribution or dynamic distribution.

  The group band 1622 is an upper limit of the band allocated to the group. The group minimum bandwidth limit amount 1623 is a lower limit of the minimum bandwidth allocated to the group.

  The device information 1624 includes three items: a device identifier 16241, a device status 16242, and a bandwidth ratio 16243. The device identifier 16241 is an identifier that uniquely indicates the communication speed-up device 2.

  The device status 16242 indicates whether the communication speed increasing device 2 is operating or stopped. Regardless of the device group type 1621, the active communication speed-up device 2 is the target of the bandwidth allocation process.

  The bandwidth ratio 16243 is a weighting factor for bandwidths divided into groups when the device group type 1621 specifies static distribution.

  FIG. 40 is an explanatory diagram showing the communication speed-up device 2 having the device group management function of this embodiment.

  FIG. 40A is a block diagram showing the configuration of the communication speed-up device 2 having the device group management function of this embodiment.

  The communication speed-up device 2 in FIG. 40A includes a processing unit and DB included in the communication speed-up device 2 in FIG. 3 and a device group information DB 262. The device group information DB 262 indicates a group to which the communication speed increasing device 2 belongs. In principle, the device group information DB 262 of the communication speed-up device 2 manages only the information of the device group to which the communication speed-up device 2 itself belongs.

  FIG. 40B is an explanatory diagram illustrating the device group information DB 262 according to this embodiment.

  The device group information DB 262 includes a device group identifier 2620, a device group type 2621, a group bandwidth 2622, a group minimum bandwidth limit amount 2623, and one or more pieces of device information 2624 (2624-1 to 2624-N).

  The device group identifier 2620, the device group type 2621, the group bandwidth 2622, the minimum group bandwidth limit amount 2623, and the device information 2624 are the device group identifier 1620, the device group type 1621, the group bandwidth 1622, and the minimum group bandwidth of the bandwidth control server 1. This corresponds to a limit amount 1623 and device information 1624.

  FIG. 41 is a block diagram showing the configuration of the communication speed-up device 2 provided in the terminal / server 3 of this embodiment.

  The terminal / server 3 has a basic hardware configuration such as a network interface 30, a control unit (CPU) 32, an external storage device 34 such as a hard disk, an internal storage device 36 such as a memory, and a bus 38 for connecting them. Prepare. The terminal / server 3 further includes an external device interface 31 such as USB or PCI for connection with an external peripheral device.

  The communication speed-up device 2 also includes an external device interface 21 such as USB or PCI for connection to an external peripheral device. The terminal / server 3 and the communication speed-up device 2 are connected via an external device interface 31 and an external device interface 21.

  The communication speed-up device 2 includes a network interface 20, a control unit (CPU) 22, a storage device 25, and a bus 28 for connecting them. The network interface 20 and control unit (CPU) 22 shown in FIG. 41 are the same as the network interface 20 and control unit (CPU) 22 shown in FIG.

  The communication acceleration program 261, device group information DB 262, device basic information DB 263, segment information DB 264, communication quality information DB 265, and session information DB 267 included in the storage device 25 are the communication acceleration program 261, device group information DB 262 in FIG. This is the same as the device basic information DB 263, segment information DB 264, communication quality information DB 265, and session information DB 267.

  In the configuration of FIG. 41, the segment information DB 264 may be used to divide a virtual server into segments when the terminal / server 3 has a virtual environment and a plurality of virtual servers operate on the terminal / server 3. .

  A time series diagram is used for registration processing of the communication speed increasing device 2 in the system, device group information update processing, and bandwidth allocation processing using the device group information when the communication speed increasing device 2 is managed as a group. explain.

  FIG. 42A is a sequence diagram illustrating a registration process to the system of the communication speed increasing apparatus 2 according to the present embodiment.

  In order to register the communication speed-up device 2 with the bandwidth control server 1, the communication speed-up device 2 transmits device information registration to the bandwidth control server 1 (S5-01).

  When the device information registration is received, the bandwidth allocation program 161 of the bandwidth control server 1 stores the device identifier, device address, device bandwidth, and minimum bandwidth limit amount in the message of S5-01 in the communication speed-up device information DB 163. To do. Next, the bandwidth allocation program 161 of the bandwidth control server 1 searches the device group information DB 162 using the device identifier to determine whether or not the communication speedup device 2 that transmitted the device information registration belongs to the group. It is determined whether or not the device identifier 16241 can extract the line indicating the communication speed-up device 2 that requested registration.

  When a row is extracted from the device group information DB 162 and it is determined that the communication speed-up device 2 belongs to any group, the bandwidth allocation program 161 sets the device status 16242 of the row extracted from the device group information DB 162 to “active”. Set to Medium. The device status 16242 to which the value is set is included in the device information 1624 indicated by the device identifier 16241 of the communication speed-up device 2 that has transmitted the device information registration.

  When the device group type 1621 of the extracted row indicates “static distribution”, the bandwidth allocation program 161 transmits the device information registration according to the group bandwidth 1622 of the extracted row and the bandwidth ratio 16243. The device band 1633 of the speed-up device 2 is calculated according to Equation 3. The bandwidth ratio 16243 used here is included in the device information 1624 indicated by the device identifier 16241 of the communication speed-up device 2 that transmitted the device information registration.

Device bandwidth 1633 = Group bandwidth 1622 × (Band ratio 16243 of communication speed-up device 2) / (Sum of bandwidth ratios 16243 of all communication speed-up devices operating in the group)
(Formula 3)
Then, the bandwidth allocation program 161 uses the extracted group minimum bandwidth limit amount 1623 and the bandwidth ratio 16243 to calculate the minimum bandwidth limit amount 1634 of the communication speed-up device 2 that transmitted the device information registration according to Equation 4. calculate.

Minimum bandwidth limit 1634 = Group minimum bandwidth limit 1623 × (Band ratio 16243 of communication speed-up device 2) / (Sum of bandwidth ratios 16243 of all communication speed-up devices 2 operating in the group) (Formula 4)
Since the device bandwidth 1633 and the minimum bandwidth limit 1634 are calculated as described above, the device bandwidth 1633 and the minimum bandwidth limit 1634 of each communication speed-up device 2 belonging to each of the groups are added to the group. Changes each time is registered. Therefore, the device bandwidth 1633 and the minimum bandwidth limit 1634 are calculated for all active communication speed-up devices 2 included in the group.

  After calculating the device bandwidth 1633 and the minimum bandwidth limit 1634 of all the communication speed-up devices 2 in the group, the bandwidth allocation program 161 uses the newly calculated device bandwidth 1633 and the minimum bandwidth limit 1634. The information of all the corresponding communication speed-up devices 2 in the communication speed-up device information DB 163 is updated.

  Through these processes, the bandwidth allocation program 161 updates the device group information DB 162 and the communication speedup device information DB 163 (S5-04).

  After S5-04, the bandwidth allocation program 161 transmits group information to the communication speed-up device 2 that has requested registration (S5-07).

  FIG. 62B is an explanatory diagram showing a message format including group information according to the present embodiment.

  PF-11 shown in FIG. 62 (b) is a message format including group information. PF-11 is a message source address, destination address, packet type (indicating that it is group information), device group identifier (corresponding to device group identifier 1620), device group type (corresponding to device group type 1621), It includes a group band (corresponding to group band 1622), a minimum group band limit (corresponding to group minimum band limit 1623), and one or more pieces of device information (corresponding to device information 1624). The corresponding value of the device group information DB 162 is stored in PF-11.

  When receiving the group information, the communication speedup device 2 stores each item included in the PF-11 in the device group information DB 262. The PF-11 is transmitted not only to the communication speedup device 2 that has requested registration of the device, but also to all the communication speedup devices 2 that belong to the same group as the communication speedup device 2 that has requested registration (S5-10). .

  After S5-10, the bandwidth allocation program 161 searches the communication quality information DB 165 using the device identifier included in the device information registration received in step S5-01, and sets the device identifier included in the device information registration to the device identifier 1650. The line indicated by is extracted. The bandwidth allocation program 161 extracts the communication quality information to be notified to the communication speed increasing device 2 from the extracted row, and then transmits the extracted communication quality information to the communication speed increasing device 2 (S5-13).

  The message format of the communication quality information in S5-13 is as shown in PF-02 in FIG. When the communication quality information is received, the communication speed increasing program 261 stores all the communication quality information in the message in the communication quality information DB 165.

  FIG. 42B is a sequence diagram illustrating device registration processing when the communication speed increasing device 2 manages the communication quality information according to the present embodiment.

  As in S5-01 in FIG. 42A, the communication speed-up device 2 transmits device information registration to the bandwidth control server 1 (S6-01).

  When the device information registration is received, the bandwidth allocation program 161 searches the device group information DB 162 using the device identifier, and updates the device group information DB 162 and the communication speedup device information DB 163 (S6-04).

  The update process executed in S6-04 is the same process as S5-04 in FIG. 42A. After updating the device group information DB 162 and the communication speed-up device information DB 163, the bandwidth allocation program 161 transmits group information to the communication speed-up device 2 that newly requested device registration (S6-07), and device registration. The group information is transmitted to all the other communication speed-up devices 2 belonging to the same group as the communication speed-up device 2 that has requested (S6-10). The processes of S6-07 and S6-10 are the same as S5-07 and S5-10 of FIG. 42A.

  When the transmission of the group information is completed, the bandwidth allocation program 161 transmits device information registration completion to the communication speed-up device 2 (S6-13). S6-13, 16, and 19 are the same as S2-04, 07, and 10 in FIG. 4B.

  FIG. 43 is a flowchart showing the bandwidth allocation processing when the communication speedup apparatus 2 of the present embodiment belongs to a group.

  When the device group type 1621 belongs to a group indicating static distribution, the communication speed-up device 2 is assigned the device bandwidth 1633 and the minimum bandwidth limit amount by the processing shown in FIG. 42A or 42B described above. For this reason, when performing bandwidth allocation processing such as S3-10 and S3-13 in FIG. 5 or S4-10 and S4-13 in FIG. It can be processed as the speed-up device 2 (or a single segment). Accordingly, the bandwidth allocation program 161 performs bandwidth allocation processing using a group to the communication speedup devices 2 belonging to the group in which the device group type 1621 indicates dynamic distribution.

  The bandwidth allocation program 161 extracts all the rows from which the device group type 1621 indicates dynamic distribution from 162. Then, device identifiers 16241 of all device information 1624 included in the extracted 162 rows are extracted. Furthermore, the bandwidth allocation program 161 extracts the extracted device identifier 16241 from the line of the communication quality information DB 165 indicated by the device identifier 1650, and extracts the extracted device identifier 16241 from the session information DB 167 indicated by the device identifier 1670. A line is extracted (F9-04).

  In the following description, 162 rows extracted in F9-04 are referred to as rows relating to group A.

  After F9-04, the band allocation program 161 is based on the extracted line of the communication quality information DB 165, the extracted line of the session information DB 167, the group band 1622 of the group A, and the group minimum band limit 1623. Thus, the minimum bandwidth 1679 is allocated to all the sessions in the group A (F9-07).

  The procedure for allocating the minimum bandwidth 1679 includes the processing up to F1-10 in FIG. 8, the processing up to F2-13 in FIG. 11, the processing up to F3-16 in FIG. 13, or the processing up to S4-13 in FIG. It is the same. However, the bandwidth allocation program 161 uses the group minimum bandwidth limit amount 1623 instead of the minimum bandwidth limit amount 1634 in each process.

  By F9-07, the bandwidth allocation program 161 can ensure the minimum communication quality and reduce the occurrence of congestion even when the base 5 is provided with a plurality of communication speed-up devices 2.

  After F9-07, the bandwidth allocation program 161 compares the minimum bandwidth 1679 of the reception side session and the transmission side session of the same session in the same way as F1-13 of the minimum bandwidth allocation processing for each device, and the smaller one is the session. The lowest bandwidth 1679 is determined (F9-10).

  After completing the allocation of the minimum bandwidth 1679 by F9-10, the bandwidth allocation program 161 calculates the remaining bandwidth for the group A from the group bandwidth 1622 of the group A and the allocation status of the minimum bandwidth 1679 (F9-13). The process shown in F9-13 is executed by using the group band 1622 instead of the apparatus band 1633 in F5-04 shown in FIG.

  After F9-13, the bandwidth allocation program 161 uses the communication quality information DB 165 extracted in F9-04 and the row of 167 to convert the calculated remaining bandwidth into the communication speedup devices 2 belonging to the group A. (F9-16). The processing of F9-16 is the processing up to F5-19 shown in FIG. 21, the processing up to F6-13 shown in FIG. 24, the processing up to F7-28 shown in FIG. 27, or the processing up to F8-13 shown in FIG. It is executed in the same way as the above process.

  After F9-16, the bandwidth allocation program 161 adds the lowest bandwidth 1679 per session allocated in F9-10 and the remaining bandwidth per session allocated in F9-16, thereby The upper limit bandwidth 1678 per session is calculated (F9-19).

  After F9-19, the bandwidth allocation program 161 adjusts the upper limit bandwidth 1678 in the same manner as F5-25 shown in FIG. 21 (F9-22). When there are a plurality of groups A, the bandwidth allocation program 161 executes the processes of F9-07, 10, 13, 16, 19, and 22 for each of the plurality of groups.

  Differences between the process of allocating a band for each group and the process of allocating a band for each communication speed-up device 2 will be described below. The first difference is that in the process of allocating a band for each group, a session for allocating a band is a session established in all the communication speed increasing devices 2 belonging to the group. The second difference is that when calculating the minimum bandwidth 1679 and the upper limit bandwidth 1678, the bandwidth allocation program 161 uses the group 1633 and the minimum bandwidth limit 1634 of the communication speed-up device 2 instead of the device bandwidth 1633 and the minimum bandwidth limit 1634. The band 1622 and the group minimum band limit 1623 are used.

  When calculating the upper limit bandwidth 1678 for each session, the bandwidth allocation program 161 compares the bandwidth of the transmission session in one session with the bandwidth of the reception session, and determines the smaller bandwidth as the upper limit bandwidth 1678 of the session. At this time, an unused band is generated in the communication speed-up device 2.

  For example, in the session information DB 167 illustrated in FIG. 22A, the upper limit bandwidth 1678 of the session having the session identifier 1671 of “SS1-1” and the upper limit bandwidth 1678 of the session having the session identifier 1671 of “SS2-1” are illustrated in FIG. The upper limit band 1678 of FIG. 22B is updated by the processing shown in F5-25.

  More specifically, as a result of F5-25 shown in FIG. 21, the upper limit band 1678 of the session “SS2-1” is updated from 66.6 Mbps to 33.3 Mbps. At this time, an unused bandwidth of 33.3 Mbps (= 66.6-33.3) is generated in the session “SS2-1”.

  Furthermore, in addition to the unused bandwidth 33.3 Mbps caused by the session SS2-1, the communication speed increasing device 2-2 uses the unused bandwidth 16.6Mbps (= 33.Mbps) for the session having the session identifier 1671 of “SS2-2”. 3-16.7). Since the communication speed-up device 2-2 is not communicating with any device other than the communication speed-up device 2-1, the generated unused band is not used for other sessions.

  However, in the configuration of FIG. 6, when another session is established between the communication speed-up device 2-2 and the communication speed-up device 2-3, the above-described unused band may be used. . After calculating the upper limit bandwidth 1678 of the session, the unused bandwidth remaining in the communication speed-up device 2 is hereinafter referred to as a surplus bandwidth. By minimizing the surplus bandwidth, it becomes possible to maximize the utilization efficiency of the communication bandwidth.

  FIG. 44 is an explanatory diagram illustrating an example of the communication speed increasing device information DB 163 according to the present embodiment.

  FIG. 45 is an explanatory diagram showing the session information DB 167 after adjusting the upper limit bandwidth 1678 of this embodiment.

  In the example shown below, the bandwidth control system shown in FIG. 1 includes communication speed-up devices 2-1, 2-2, 2-3, 2-4. Further, in the bandwidth control server 1 of the bandwidth control system shown in FIG. 1, the communication speed increasing device information DB 143 shown in FIG. 44 and the communication quality information DB 145 shown in FIG. 26 are set. Further, a session in the bandwidth control system is established as in the session information DB 147 shown in FIG.

  The device bands 1633 of the communication speed-up devices 2 are not the same. Specifically, the device bandwidth 1633 of the communication speed-up device 2-1 is 25 Mbps, which is the smallest among the communication speed-up devices 2 provided in the bandwidth control system. Further, the device bandwidth 1633 of the communication speed increasing device 2-4 is 100 Mbps, which is the largest among the communication speed increasing devices 2 included in the bandwidth control system.

  The session information DB 167 of FIG. 45 shows a state in which one transmission session and one reception session by CIFS are established between all the communication speed-up devices 2. Taking the communication speed-up device 2-1 as an example, the communication speed-up device 2-1 transmits data to the communication speed-up devices 2-2, 2-3, 2-4 and simultaneously receives the data. Establish a session.

  FIG. 45 shows a result of adjusting the upper limit band 1678 by comparing the transmission session and the reception session. In the session information DB 167 illustrated in FIG. 45, the thick frame column indicates the upper limit band 1678 that has decreased as a result of adjustment.

  The bandwidth allocation program 161 adds the surplus bandwidth 1690 to the session information DB 167 when the surplus bandwidth is used by another session. The surplus bandwidth 1690 is a bandwidth corresponding to a decrease in the upper limit bandwidth 1678 as a result of adjustment.

  Note that the upper limit band 1678 shown in FIG. 45 and the surplus band 1690 shown in FIG. 45 indicate bands by fractions. For example, 25/3 indicates 25 divided by 3.

  FIG. 46 is an explanatory diagram illustrating the surplus bandwidth information 170 in the communication speed increasing device 2 according to the present embodiment.

  The surplus bandwidth information 170 illustrated in FIG. 46 is information obtained by extracting the surplus bandwidth 1690 of the session information DB 167 illustrated in FIG. 45 according to the device identifier 1670 and the communication type 1673. The surplus bandwidth information 170 is temporarily generated in the internal storage device 16 of the bandwidth control server 1 by the bandwidth allocation program 161.

  The surplus bandwidth information 170 includes a device identifier 1701, a surplus transmission bandwidth 1702, and a surplus reception bandwidth 1703. The device identifier 1701 is an identifier for uniquely identifying the communication speed increasing device 2. The remainder transmission band 1702 and the remainder reception band 1703 store the sum of the device identifier 1670 and the remainder band 1690 for each communication type 1684.

  For example, the surplus transmission band 1702 whose device identifier 1701 is “device 2” is the surplus bandwidth 1690 of the row of the session information DB 167 whose device identifier 1670 is “device 2” and whose communication type 1674 is “transmission”. It is the sum.

  Further, for example, the surplus reception band 1703 whose device identifier 1701 is “device 3” is the surplus bandwidth of the row of the session information DB 167 whose device identifier 1670 is “device 3” and whose communication type 1684 is “reception”. The sum of 1690.

  The device band 1633 of the communication speed-up device 2-1 (device identifier 1631 is “device 1”) is 25 Mbps, which is the smallest among the four communication speed-up devices 2. Therefore, no surplus bandwidth 1690 is generated in the communication speed-up device 2-1. On the other hand, the communication speed increasing device 2-4 (device identifier 1631 is “device 4”) has the maximum device bandwidth 1633, and the sum of the surplus bandwidth 1690 is also the maximum.

  In the example shown in FIG. 45, since the surplus bandwidth 1690 exists in the communication speed-up devices 2-2, 2-3, and 2-4, the surplus bandwidth can be used for the session between the communication speed-up devices 2. By adding as a band, the unused band can be minimized and the communication efficiency can be optimized. The final band allocation result differs depending on which session the surplus band 1690 is allocated to. Here, the following two remaining bandwidth allocation algorithms will be described.

  The first residual bandwidth allocation algorithm is a residual bandwidth recursive allocation scheme. The second surplus bandwidth allocation algorithm is a maximum surplus bandwidth priority allocation scheme.

  FIG. 47 is a flowchart showing the remaining bandwidth recursive allocation method of the present embodiment.

  In the recursive allocation method, the bandwidth allocation program 161 recursively allocates the residual bandwidth 1690 to the session of each communication acceleration device 2 using an algorithm for allocating the remaining bandwidth of the communication acceleration device 2.

  First, the bandwidth allocation program 161 assigns the residual bandwidth 1690 to the session of each communication speedup device 2 using an algorithm for assigning the remaining bandwidth of the communication speedup device 2 (F10-04).

  Note that the algorithm for allocating the remaining bandwidth is processing starting from F7-07 shown in FIG. This is because the bandwidth setting type 1657 of the communication quality information DB 165 indicates session bandwidth designation when executing the processing shown in FIG. However, in this case, the bandwidth allocation program 161 does not perform F7-19 and F7-22, but executes up to F7-28.

  In the example of FIG. 46, a CIFS data communication session is established between the communication speed-up devices 2-2, 2-3, and 2-4. A specific example of F10-04 will be described below.

  First, the bandwidth allocation program 161 updates the surplus bandwidth 1690 of the transmission session of the communication speed-up device 2 in which the surplus transmission bandwidth 1702 is not 0 in F10-04. Here, the bandwidth allocation program 161 divides the surplus bandwidth 1690 of the session between the communication speedup devices 2 other than the communication speedup device 2 in which the surplus bandwidth 1690 is all zero.

  Two transmission sessions of the transmission session from the communication speed increasing device 2-2 to the communication speed increasing device 2-3 and the transmission session from the communication speed increasing device 2-2 to the communication speed increasing device 2-4 are the same service. It is. For this reason, the bandwidth allocation program 161 divides the remainder transmission band 1702 of the communication speed-up device 2-2 equally into two in F10-04, and is divided as a new remainder band 1690 of two transmission sessions. The surplus transmission band 1702 is stored in 167.

  In F10-04, the bandwidth allocation program 161 uses the surplus bandwidth 1690 of the transmission session from the communication speed-up device 2-3 to the communication speed-up device 2-2 and the communication speed-up from the communication speed-up device 2-3. The surplus bandwidth 1690 of the transmission session to the device 2-4 is updated with a bandwidth that is obtained by equally dividing the surplus transmission bandwidth 1702 of the communication speed increasing device 2-3. The bandwidth allocation program 161 also transmits the surplus bandwidth 1690 of the transmission session from the communication speed increasing device 2-4 to the communication speed increasing device 2-2, and from the communication speed increasing device 2-4 to the communication speed increasing device 2-3. As for the surplus bandwidth 1690 of the transmission session, the surplus transmission bandwidth 1702 of the communication speed-up device 2-4 is updated by the equally divided bandwidth.

  Furthermore, the bandwidth allocation program 161 updates the surplus bandwidth 1690 of the reception session of the communication speed-up device 2 in which the surplus reception bandwidth 1703 is not 0 by the same method as that of the transmission session described above.

  Then, in F10-04, the bandwidth allocation program 161 compares the surplus bandwidth 1690 of the transmission session with the surplus bandwidth 1690 of the reception session in F10-04, and uses the lower surplus bandwidth 1690 as the reallocation bandwidth 1691. To store.

  FIG. 48 is an explanatory diagram illustrating an example of the session information DB 167 in the reallocation process of the surplus bandwidth 1690 according to the present embodiment.

  The bandwidth allocation program 161 adds a reallocation bandwidth 1691 to the session information DB 167 in F10-04. The reallocation band 1691 is the result of F10-04. 48 shows only the row of the session information DB 167 to which the reallocation band 1691 has been added as a result of executing F10-04 on the session information DB 167 shown in FIG.

  After updating the surplus bandwidth 1690 in F10-04, the bandwidth allocation program 161 updates the surplus bandwidth 1690 with a value obtained by subtracting the reallocation bandwidth 1691 from the surplus bandwidth 1690 (F10-07). A thick remainder band 1690 shown in FIG. 48 indicates the result of F10-07.

  FIG. 49 is an explanatory diagram illustrating an example of the surplus bandwidth information 170 after the first surplus bandwidth allocation process according to the present embodiment.

  The bandwidth allocation program 161 generates a surplus bandwidth 1690 shown in FIG. 49 based on the session information DB 167 including the surplus bandwidth 1690 shown in FIG. 48 in F10-07.

  After F10-07, the bandwidth allocation program 161 determines whether there is a surplus transmission bandwidth 1702 that can be allocated to a session with another communication speed-up device 2 (F10-10). The bandwidth allocation program 161 determines that there is a surplus transmission bandwidth 1702 that can be allocated to a session with another communication speedup device 2 when there are two or more communication speedup devices 2 for which the remainder transmission bandwidth 1702 is not zero. .

  As a result of the determination, if there is no allocable residual transmission band 1702, the band allocation program 161 ends the band allocation process. When there is an assignable surplus transmission band 1702, the band allocation program 161 recursively performs a band allocation process on the surplus band 1690 shown in FIG. 48 (F10-04).

  FIG. 50 is an explanatory diagram illustrating an example of the session information DB 167 after the second surplus bandwidth allocation process according to the present embodiment.

  49 shows the result that the surplus bandwidth 1690 of FIG. 49 is assigned to each session between the communication speed-up device 2-3 and the communication speed-up device 2-4 by F10-04 and F10-07. In FIG. 50, the surplus bandwidth 1690 other than the communication speed increasing device 2-4 is zero. For this reason, also in the surplus bandwidth information 170, the surplus transmission bandwidth 1702 other than the communication speed increasing device 2-4 is zero. For this reason, no more surplus bandwidth 1690 can be assigned to each communication speed-up device 2. Therefore, FIG. 50 shows the final band allocation result by the processing shown in FIG.

  Note that the bandwidth allocation program 161 adds the value of the reallocation bandwidth 1691 of each session to the upper limit bandwidth 1678 after completing the processing shown in FIG.

  FIG. 51 is a flowchart showing the maximum remainder bandwidth priority allocation method according to the present embodiment.

  In the maximum surplus bandwidth priority allocation method, the bandwidth allocation program 161 preferentially allocates the surplus transmission bandwidth 1702 of the communication speed-up device 2 having the largest surplus transmission bandwidth 1702. In the surplus bandwidth information 170 shown in FIG. 46, the surplus transmission bandwidth 1702 is the largest in the communication speed increasing device 2-4.

  Therefore, the band allocation program 161 divides the surplus transmission band 1702 of the communication speedup apparatus 2-4 into other communication speedup apparatuses 2 as much as possible (F11-04). At that time, there are a method of sequentially assigning the surplus transmission band 1702 to the communication speed-up device 2 having a small surplus reception band 1703 and a method of sequentially assigning the surplus transmission band 1702 to the communication speed-up device 2 having a large surplus reception band 1703. is there.

  When allocating the surplus transmission bandwidth 1702 in the surplus bandwidth information 170 of FIG. 46, the bandwidth allocation program 161 allocates 75/3 Mbps from the surplus transmission bandwidth 1702 of the communication speedup device 2-4 to the communication speedup device 2-3, 25/3 Mbps can be allocated to the communication speed-up device 2-2. After allocating the surplus bandwidth, the bandwidth allocation program 161 updates the surplus bandwidth 1690 with a value obtained by subtracting the allocated bandwidth from the surplus bandwidth 1690 (F11-07).

  After updating the surplus bandwidth 1690 in F11-07, the bandwidth allocation program 161 determines whether there is an assignable surplus transmission bandwidth 1702 (F11-10). As a result of updating the surplus bandwidth 1690 in F11-07, when there is no assignable surplus transmission bandwidth 1702, the bandwidth allocation program 161 ends the processing shown in FIG. If there is an assignable surplus transmission band 1702, the band allocation program 161 executes the surplus band allocation process again (F11-04).

  FIG. 52 is an explanatory diagram showing the residual bandwidth information 170 after the residual bandwidth allocation processing by the maximum residual bandwidth priority allocation method according to the present embodiment.

  In the state of the surplus bandwidth information 170 in FIG. 46, as a result of reassigning the surplus bandwidth by the maximum surplus bandwidth priority allocation method, the surplus bandwidth of the entire bandwidth control system changes as the surplus bandwidth information 170 shown in FIG. In the surplus bandwidth information 170 shown in FIG. 52, since there is only one communication speed-up device 2 in which the surplus transmission bandwidth 1702 is not 0, the bandwidth allocation program 161 does not have a surplus transmission bandwidth 1702 that can be assigned F11-0. Is determined. Therefore, the surplus bandwidth allocation process ends.

  The bandwidth allocation program 161 adds the surplus bandwidth 1690 to the upper limit bandwidth 1678 of each session in the row of the session information DB 167 indicating the communication speed-up device 2 other than the communication speed-up device 2 having the largest surplus transmission bandwidth 1702. .

  FIG. 53 is a sequence diagram illustrating the overall flow of the bandwidth allocation processing according to this embodiment.

  After receiving the session information from each of the plurality of communication speed-up devices 2 (S7-01, 04, 07), the bandwidth allocation program 161 of the bandwidth control server 1 reads the device group, the segment of each communication speed-up device 2, or Then, the minimum bandwidth 1679 is calculated for each of the communication speed increasing devices 2, and the minimum bandwidth 1679 is assigned to each session (S7-10). S7-10 corresponds to S3-10 illustrated in FIG.

  After allocating the lowest bandwidth 1679 in S7-10, the bandwidth allocation program 161 calculates the remaining bandwidth of each communication acceleration device 2, and assigns the remaining bandwidth to each session, thereby calculating the upper limit bandwidth 1678 of each session. (S7-13). S7-13 corresponds to S3-13 illustrated in FIG.

  After S7-13, the bandwidth allocation program 161 allocates bandwidth to each session again using the surplus bandwidth 1690 generated in the process of calculating the maximum bandwidth 1678, and recalculates the maximum bandwidth 1678 (S7-16). By S7-16, the unused band (remaining band 1690) generated in each of the communication speed increasing devices 2 can be reduced.

  After S7-16, the bandwidth allocation program 161 notifies each communication speed-up device 2 of the calculated upper limit bandwidth 1678 and the lowest bandwidth 1679 as bandwidth information (S7-19, 22, 25). When the bandwidth information is received from the bandwidth control server 1, the communication speedup device 2 performs the speedup processing of communication within the given bandwidth range.

  The final band allocation result varies depending on the remaining band allocation algorithm (the process shown in FIG. 46 or 51). Therefore, the selection of the surplus bandwidth allocation algorithm is important. The remaining bandwidth recursive allocation method shown in FIG. 46 applies the remaining bandwidth allocation algorithm of the communication speed-up device 2 when dividing the bandwidth, so that the bandwidth is evenly distributed between the communication speed-up devices 2 as much as possible. it can. Therefore, it is suitable when the sessions are distributed almost evenly among the bases 5.

  On the other hand, the maximum surplus bandwidth priority allocation method shown in FIG. 51 is an algorithm that uses as much of the bandwidth of the base 5 having a large line as possible. For this reason, as shown in FIG. 6, the effect is great when sessions concentrate on one base 5.

  Which surplus bandwidth allocation algorithm is to be used may be determined in advance by the network configuration, the base 5, the device bandwidth 1633, the service operating in the bandwidth control system, or the like during system design. Further, the bandwidth allocation program 161 can realize more flexible bandwidth allocation processing according to the status of the bandwidth control system by switching the algorithm during operation of the bandwidth control system.

  For example, in the system configuration of FIG. 1, a case is considered where sessions are concentrated at the base 5-1 during the day and communication occurs between the four bases 5 at night. In such a case, the bandwidth allocation efficiency can be increased in both daytime and nighttime conditions by switching the surplus bandwidth allocation algorithm applied by dividing the time zone.

  Another method for realizing switching of the surplus bandwidth allocation algorithm is a method of calculating the bias of the distribution status of the communication session and dynamically switching the surplus bandwidth allocation algorithm according to the status. The bias of the communication session is determined using the distribution of the number of transmission sessions and the number of reception sessions of the communication speed increasing device 2.

  The variance of the number of sessions increases when there is a bias in the session distribution. For example, when the bandwidth allocation program 161 calculates the distribution of the number of transmission sessions and the distribution of the number of reception sessions based on the session information DB 167 shown in FIG. 7C, 0.19 is calculated for the distribution of the number of transmission sessions. Then, 1.69 is calculated for the distribution of the number of received sessions. This is because the reception sessions are concentrated on the communication speed-up device 2-1, whereas the transmission sessions are evenly distributed on the communication speed-up devices 2-2 to 2-4, and the bias is small. .

  On the other hand, when the bandwidth allocation program 161 calculates the distribution of the number of transmission sessions and the distribution of the number of reception sessions based on the session information DB 167 shown in FIG. 45, all the communication speed-up devices 2 have three transmission sessions and three Since there are reception sessions, 0 is calculated for both the distribution of the number of transmission sessions and the distribution of the number of reception sessions.

  From the above, the bandwidth allocation program 161 can use the absolute value of the transmission session number distribution and the reception session number distribution when determining the bias of the communication session.

  FIG. 54 is an explanatory diagram showing the bandwidth control server 1 having the function of switching the surplus bandwidth allocation algorithm according to the present embodiment.

  FIG. 54A is a block diagram illustrating a configuration of the bandwidth control server 1 having a function of switching the surplus bandwidth allocation algorithm according to the present embodiment.

  The bandwidth control server 1 in FIG. 54A has a bandwidth control schedule DB 168 in addition to the configuration in FIG.

  FIG. 54B is an explanatory diagram showing the bandwidth control schedule DB 168 of the present embodiment.

  The bandwidth control schedule DB 168 includes a schedule identifier 1680, a start time 1681, an end time 1682, an algorithm type 1683, and a dynamic switching permission 1684. The schedule identifier 1680 is an identifier for uniquely indicating a schedule set in the bandwidth control server 1.

  The bandwidth allocation program 161 applies the surplus bandwidth allocation algorithm specified by the algorithm type 1683 to the time zone specified by the start time 1681 and the end time 1682. The algorithm type 1683 indicates, for example, either the residual bandwidth recursive allocation method or the maximum residual bandwidth priority allocation method.

  The end time 1682 may be blank. When the end time 1682 is blank, the bandwidth allocation program 161 applies the surplus bandwidth allocation algorithm specified by the algorithm type 1683 after the start time 1681.

  The dynamic switching permission 1684 designates whether or not to permit dynamic switching of the algorithm due to bias in the session distribution. When the dynamic switching permission 1684 indicates “not permitted”, the bandwidth allocation program 161 performs bandwidth allocation processing based on the residual bandwidth allocation algorithm specified by the algorithm type 1683 regardless of the session distribution state.

  FIG. 55 is a sequence diagram illustrating a process of dynamically switching the surplus bandwidth allocation algorithm according to the present embodiment.

  The bandwidth allocation program 161 of the bandwidth control server 1 receives session information from each communication speed-up device 2 (S8-01, 04, 07), and updates the session information DB 167. Next, the bandwidth control schedule DB 168 is searched to determine whether or not the algorithm dynamic switching permission 1684 indicates “permitted”.

  When the dynamic switching permission 1684 indicates “permitted”, the bandwidth allocation program 161 calculates the distribution of the number of transmission sessions and the number of reception sessions based on the updated session information DB 167 (S8-10).

  Next, the bandwidth allocation program 161 calculates the absolute value of the difference between the distribution of the number of transmission sessions and the distribution of the number of reception sessions in order to determine the residual bandwidth allocation algorithm, and the calculated absolute value and the bandwidth control server 1 in advance. The set threshold value is compared (S8-13). Since the threshold value used in S8-13 is also affected by the number of communication speed-up devices 2 provided in the bandwidth control system, a value that accurately represents the distribution of sessions is set as the threshold value used in S8-13. There is a need. For example, in the configuration of the bandwidth control system in FIG. 6, 1.0 is set as the threshold used in S8-13.

  When the residual bandwidth allocation algorithm determined as a result of the determination based on the threshold is different from the currently applied residual bandwidth allocation algorithm, the bandwidth allocation program 161 switches the residual bandwidth allocation algorithm (S8-16).

  When the distribution of the number of sessions in the bandwidth control system changes frequently, switching of the surplus bandwidth allocation algorithm may occur frequently. When the surplus bandwidth allocation algorithm is frequently switched, the bandwidth allocation efficiency is reduced. For this reason, the bandwidth allocation program 161 may not allow switching of the surplus bandwidth allocation algorithm for a certain time after the surplus bandwidth allocation algorithm is switched once.

  In this case, when switching the surplus bandwidth allocation algorithm, the bandwidth allocation program 161 may set the dynamic switching permission 1684 of the bandwidth control schedule DB 168 to “not permitted”. Then, after a predetermined time elapses, the bandwidth allocation program 161 may permit subsequent switching of the surplus bandwidth allocation algorithm by setting the dynamic switching permission 1684 to “permitted” again.

  The series of bandwidth allocation processes described so far has been performed intensively by the bandwidth control server 1. However, if the bandwidth control server 1 is stopped due to a failure or a failover occurring in the bandwidth control server 1, the communication speed is increased. It is necessary to perform the bandwidth control process as far as the device 2 can.

  FIG. 56 is a sequence diagram illustrating processing when the bandwidth control server 1 according to the present embodiment is stopped.

  When a failure occurs in the bandwidth control server 1 (S9-01), the communication acceleration program 261 of the communication acceleration devices 2-1 to 2-N detects a failure in the bandwidth control server 1 (S9-04). For example, each communication speed increasing program 261 of the communication speed increasing device 2 can detect an abnormality when transmitting session information to be transmitted for bandwidth allocation.

  When the stop of the bandwidth control server 1 is detected, the bandwidth allocation program 260 (to be described later) of the communication speed increasing devices 2-1 to 2-N individually executes bandwidth allocation processing (S9-07). The bandwidth allocation processing by the communication speed increasing device 2 is executed at a predetermined cycle. Bandwidth allocation processing by the communication speed increasing device 2 is performed based on the device group information DB 262, the device basic information DB 263, the segment information DB 264, the communication quality information DB 265, and the session information DB 267.

  FIG. 57 is a block diagram showing the configuration of the communication speed-up device 2 having the bandwidth allocation function of this embodiment.

  The bandwidth allocation function of FIG. 57 is obtained by adding a bandwidth allocation program 260 to the configuration of FIG. The bandwidth allocation program 260 is a program that executes the same processing as the bandwidth allocation program 161 of the bandwidth control server 1.

  The bandwidth allocation program 260 executes, for example, S3-10 and S3-13 shown in FIG. 5 as bandwidth allocation processing.

  The bandwidth allocation processing by the communication speed-up device 2 has some restrictions compared to the bandwidth allocation processing by the bandwidth control server 1. The first restriction is that the device basic information DB 263 of the communication speed-up device 2 holds only information relating to itself, and therefore information of other communication speed-up devices 2 cannot be used for bandwidth allocation processing.

  The second restriction is that the communication speed-up device 2 does not have a function of updating the device group information DB 262. For this reason, the communication speed-up device 2 uses the received information and the set information as the device group information DB 262 immediately before the bandwidth control server 1 stops.

  These restrictions cause a reduction in the efficiency of the bandwidth allocation process. For this reason, the communication speed-up device 2 periodically checks whether or not the bandwidth control server 1 has been restored. When the recovery of the bandwidth control server 1 is detected (S9-13), the communication acceleration program 261 of the communication acceleration devices 2-1 to 2-N transmits the session information to the bandwidth control server 1 (S9-16, 19, 22). Thereafter, each communication speed-up device 2 stops the bandwidth allocation process (S9-25) and waits for the bandwidth information to be notified from the bandwidth control server 1.

  Next, the operation of each communication speed-up device 2 constituting the system will be described with reference to a flowchart.

  FIG. 58 is a flowchart for explaining the operation of the bandwidth control server 1 of this embodiment.

  The bandwidth control server 1 starts a processing loop when the bandwidth allocation program 161 is activated (F12-04). In the processing loop, the bandwidth allocation program 161 processes events generated by various messages, timers and the like received via the network interface 10. When the device information registration is received in the processing loop (F12-07), the bandwidth allocation program 161 updates the device group information DB 162 and the communication speedup device information DB 163 using the information included in the device information registration ( F12-28).

  When there is a group to which the communication speed-up device 2 that has requested registration belongs, that is, when the device group information DB 162 of the bandwidth control server 1 includes group information regarding the group to which the communication speed-up device 2 that has requested registration belongs. The bandwidth allocation program 161 transmits the group information in the device group information DB 162 to all the communication speedup devices 2 belonging to the same group as the communication speedup device 2 that has requested registration (F12-31).

  When the bandwidth control server 1 manages all the communication quality information (corresponding to the communication quality information DB 165) of the communication speed increasing device 2, the bandwidth allocation program 161 transmits the communication quality information to the communication speed increasing device 2 (F12). -55). If the bandwidth control server 1 does not have communication quality information, the bandwidth allocation program 161 proceeds to F12-37 and transmits device information registration completion to the communication speed-up device 2. And it waits for the communication speed-up apparatus 2 to register communication quality information.

  When the communication quality information registration is received in the processing loop started in F12-04 (F12-10), the bandwidth allocation program 161 updates the communication quality information DB 165 using the received information and communicates the completion of the communication quality registration. It transmits to the speed-up device 2 (F12-40). When session information is received in the processing loop started in F12-04 (F12-13), the bandwidth allocation program 161 determines whether there is a communication speedup apparatus 2 that has not received session information in a predetermined cycle. That is, it is determined whether there is unreceived session information (F12-43).

  When there is no unreceived session information, the bandwidth allocation program 161 determines whether dynamic switching of the surplus bandwidth allocation algorithm is permitted by referring to the bandwidth control schedule DB 168 (F12-46). If dynamic switching of the surplus bandwidth allocation algorithm is permitted, the bandwidth allocation program 161 proceeds to F12-49. Then, the bandwidth allocation program 161 determines whether or not the surplus bandwidth allocation algorithm should be switched based on the session distribution status by the process shown in FIG. 55, and if so, changes the surplus bandwidth allocation algorithm.

  If dynamic switching of the surplus bandwidth allocation algorithm is not permitted, the bandwidth allocation program 161 proceeds to F12-55. Then, the bandwidth allocation program 161 allocates the minimum bandwidth 1679 to each session based on the device group information DB 162, the communication speed-up device information DB 163, the segment information DB 164, the communication quality information DB 165, and the session information DB 167 (for example, in FIG. Process), allocation of the upper limit band 1678 (for example, the process shown in FIG. 21), and redistribution process of the surplus band (for example, the process shown in FIG. 47). Then, the bandwidth allocation program 161 transmits the allocated bandwidth to the communication speedup device 2 as bandwidth information (F12-55).

  In the processing loop started in F12-04, when it is detected that the start time 1681 indicated by the bandwidth control schedule DB 168 is reached (F12-19), the bandwidth allocation program 161 executes switching processing of the surplus bandwidth allocation algorithm. (F12-52). The processing loop started in F12-04 ends when the bandwidth allocation program 161 is shut down (F12-22).

  In F12-19, by switching the surplus bandwidth allocation algorithm based on the start time 1681, the bandwidth allocation program 161 can switch the surplus bandwidth allocation algorithm according to a predetermined schedule.

  FIG. 59 is a flowchart showing processing of the communication speed increasing apparatus 2 of the present embodiment.

  The communication speed-up device 2 starts a processing loop when the communication speed-up program 261 is activated (F13-04). The communication acceleration program 261 processes various messages received via the network interface 20 and events generated by a timer or the like in a processing loop.

  When it is detected in the processing loop started in F13-04 that its own device registration processing has not been performed (F13-07), the communication speed-up program 261 transmits device information registration to the bandwidth control server 1. (F13-31). Thereafter, the communication speed-up program 261 determines whether or not the communication quality information is managed by itself (F13-34).

  If the communication speed increasing device 2 manages the communication quality information by itself, the communication speed increasing program 261 proceeds to F13-37. Then, the communication speed-up program 261 transmits communication quality information registration to the bandwidth control server 1 (F13-37).

  When the communication quality information is received in the processing loop started in F13-04 (F13-10), the communication speed-up program 261 stores the received information in the communication quality information DB 265 (F13-40). When the group information is received in the processing loop (F13-13), the communication speed-up program 261 stores the received group information in the device group information DB 262 (F13-43).

  When it is detected in the processing loop started in F13-04 that the time has reached a predetermined period of the bandwidth allocation processing (F13-16), the communication speed-up program 261 sends the session information to the bandwidth control server 1 (F13-46). When bandwidth information is received in the processing loop (F13-19), the communication speed-up program 261 stores the upper limit bandwidth and the lowest bandwidth in the message in the session information DB 267 (F13-49), and the notified bandwidth The communication speeding-up process is executed within the range (F13-52).

  When the communication speed-up program 261 detects that the bandwidth control server 1 is stopped in the processing loop started in F13-04 (F13-22), the communication speed-up program 261 starts the bandwidth allocation program 260. Then, the bandwidth allocation program 260 starts bandwidth allocation processing (F13-55). When the communication speed-up program 261 detects restoration of the bandwidth control server 1 in the processing loop (F13-25), the communication speed-up program 261 transmits session information to the bandwidth control server 1 and stops the bandwidth allocation program 260. (F13-58).

  In F13-22, when the communication speed increasing device 2 executes the bandwidth allocation process when the bandwidth control server 1 is stopped, the communication speed increasing device 2 can continue to secure communication quality and reduce congestion.

  In F13-04, the processing loop ends when the communication speed-up program 261 is shut down (F13-28).

  According to the present embodiment, by assigning the minimum bandwidth 1679 and the upper limit bandwidth 1678 based on session information in the bandwidth control system, congestion can be reduced and communication quality can be guaranteed. Also, the unused bandwidth can be reduced by dividing the surplus bandwidth 1690 and assigning it to the session. Thereby, the bandwidth control server 1 of the present embodiment can optimize the entire network in the bandwidth control system.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described.

  Each of the above-described configurations, functions, processing units, processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit. Each of the above-described configurations, functions, and the like may be realized by software by interpreting and executing a program that realizes each function by the processor. Information such as programs, tables, and files for realizing each function can be stored in a recording device such as a memory, a hard disk, or an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD.

  Further, the control lines and information lines in the bandwidth control server 1 are those that are considered necessary for explanation, and not all the control lines and information lines on the product are necessarily shown. Actually, it may be considered that almost all the components are connected to each other.

  The bandwidth control server 1 and the bandwidth control system of the present invention can be applied to a distributed system that provides services such as data transfer and Web service by connecting a large number of bases 5 with a wide-area network having a relatively large delay. In particular, it is expected to be applied to cloud services that provide multiple services through a data center.

1 Bandwidth Control Server 2 Communication Speedup Device 3 Terminal / Server 4 Network 5 Base 6 Department

Claims (14)

A network system comprising a plurality of communication devices accommodating a plurality of sessions, and a bandwidth control server connected to each of the plurality of communication devices,
The bandwidth control server is
With memory and network interface,
Communication quality information including information for calculating a minimum bandwidth to be allocated at least to each of the plurality of sessions in the memory;
From each of the plurality of communication devices, session information related to a session accommodated by the communication device is received via the network interface,
Based on the received session information and the communication quality information, the minimum bandwidth is allocated to each of the plurality of sessions,
Each of the allocated minimum bandwidths is notified to each of the plurality of communication devices. A network system according to claim 1, wherein
The communication quality information further includes information for calculating an upper limit band indicating an upper limit of a band to be allocated to each of the plurality of sessions,
The bandwidth control server is
Communication device information indicating an upper limit value of a bandwidth allocated to each of the plurality of communication devices, further having in the memory,
Based on the communication device information, the communication quality information, and the allocated minimum bandwidth, the upper limit bandwidth is allocated to each of the plurality of sessions,
Each of the allocated upper limit bandwidths is notified to each of the plurality of communication devices. The network system according to claim 2, wherein
The bandwidth control server is
When the second upper limit band assigned to the first session accommodated by the second communication device is larger than the first upper limit bandwidth assigned to the first session accommodated by the first communication device, A value obtained by subtracting the first upper limit band from the second upper limit band is calculated as a surplus band of the second communication device;
The network system, wherein the calculated surplus bandwidth is allocated to at least one session other than the first session accommodated by the second communication device. A network system according to claim 3, wherein
The bandwidth control server is
Bandwidth control information including a plurality of algorithms for dividing the surplus bandwidth and information indicating whether each of the plurality of algorithms can be dynamically changed, further includes in the memory,
When the second communication device accommodates a plurality of sessions other than the first session, the calculated surplus bandwidth is divided and assigned by an algorithm determined according to the bandwidth control information. . A network system according to claim 4, wherein
The bandwidth control server is
A distribution of the number of sessions accommodated by each of the plurality of communication devices is calculated based on the received session information,
If the previous period band control information indicates that each of the plurality of algorithms can be dynamically changed, one of the plurality of algorithms is divided into the calculated remainder band according to the calculated distribution. A network system characterized by being determined as an algorithm. A network system according to claim 5, wherein
The bandwidth control server is
By one of the plurality of algorithms,
Calculating the surplus bandwidth of each of the plurality of communication devices;
Identify the communication device with the largest calculated surplus bandwidth,
A network system, wherein a surplus bandwidth calculated for each of the plurality of communication devices other than the specified communication device is assigned to a session accommodated in the specified communication device. A network system according to claim 6, wherein
The bandwidth control information further includes a start time to start applying at least one of the plurality of algorithms,
The bandwidth control server starts applying the at least one algorithm at a start time indicated by the bandwidth control information. A network system according to any one of claims 1 to 7,
The communication quality information includes, as information for calculating the minimum bandwidth, information indicating each service of the plurality of sessions and a bandwidth allocated to the service at a minimum in each of the plurality of communication devices, Including
The session information further includes the number of sessions accommodated by each of the plurality of communication devices, and information indicating a service of the session,
The bandwidth control server is
Based on the communication quality information and the session information, the minimum bandwidth allocated to the service in each of the plurality of communication devices is divided by the number of sessions of the service accommodated by each of the plurality of communication devices,
The network system, wherein the divided result is assigned to each of the plurality of sessions as the minimum bandwidth. A network system according to any one of claims 1 to 7,
Each of the plurality of communication devices is connected to a plurality of terminals communicating through a session accommodated by each of the plurality of communication devices,
Each of the plurality of terminals is classified into the plurality of segments,
The bandwidth control server is
The memory further includes segment information including information indicating each of the plurality of segments and a minimum segment bandwidth allocated to each of the plurality of segments.
The minimum bandwidth is allocated to each of the plurality of sessions so as not to exceed the minimum segment bandwidth of each of the plurality of segments based on the segment information, the communication quality information, and the session information. Network system. A network system according to any one of claims 1 to 7,
Each of the plurality of communication devices is divided into a plurality of groups,
The bandwidth control server is
The memory further includes group information including information indicating each of the plurality of groups and a minimum group bandwidth allocated to each of the plurality of groups.
Allocating the minimum bandwidth to each of the plurality of sessions based on the group information, the communication quality information, and the session information so as not to exceed the group minimum bandwidth of each of the plurality of groups. Network system. A network system according to any one of claims 1 to 7,
The session information includes a data amount of the session in a buffer that each of the plurality of communication devices has to accommodate each of the plurality of sessions.
The bandwidth control server is
A network system, wherein the minimum bandwidth is allocated to each of the plurality of sessions according to a ratio of the data amount of each of the plurality of sessions based on the communication quality information and the session information. A network system according to any one of claims 1 to 7,
Each of the plurality of communication devices includes a memory and a network interface,
The third communication device is
Communication quality information including information for calculating a minimum bandwidth to be allocated at least to each of the plurality of sessions;
Session information related to a session accommodated by the third communication device, and a memory included in the communication device,
A network system, wherein when the bandwidth control server is stopped, the minimum bandwidth is allocated to each of the plurality of sessions based on session information and communication quality information of the third communication device. A bandwidth control method by a plurality of communication devices accommodating a plurality of sessions, and a bandwidth control server connected to each of the plurality of communication devices,
The bandwidth control server includes a processor, a memory, and a network interface,
The method
The processor stores, in the memory, communication quality information including information for calculating a minimum bandwidth to be allocated to each of the plurality of sessions at a minimum;
The processor receives, from each of the plurality of communication devices, session information regarding a session accommodated by the communication device via the network interface,
The processor allocates the minimum bandwidth to each of the plurality of sessions based on the received session information and the communication quality information;
The bandwidth control method, wherein the processor notifies each of the plurality of communication devices of each of the allocated minimum bandwidths. A plurality of communication devices accommodating a plurality of sessions, and a bandwidth control server connected to each of the plurality of communication devices,
The bandwidth control server is
With memory and network interface,
Communication quality information including information for calculating a minimum bandwidth to be allocated at least to each of the plurality of sessions in the memory;
From each of the plurality of communication devices, session information related to a session accommodated by the communication device is received via the network interface,
Based on the received session information and the communication quality information, the minimum bandwidth is allocated to each of the plurality of sessions,
A bandwidth control server that notifies each of the plurality of communication devices of each of the allocated minimum bandwidths.

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