JP2020102692A - Medium adapter device, distribution communication management method, and distribution communication management program - Google Patents

Abstract

To provide a medium adapter device capable of avoiding abnormality of communication due to overload or a fault in a radio channel and securing a radio band.SOLUTION: A medium adapter device includes: as a medium adapter device 3 for performing medium conversion, a main channel interface 4 for connecting a main radio communication terminal 5 for transmitting/receiving a radio signal of data flowing through a main radio channel; and one or more band-securing interfaces 11 for connecting each of one or more band-securing communication terminals 12 for securing a radio band. When a data packet addressed to a center router device 10 is received from a router device 1, the medium adapter device sequentially distributes the data packet, in a round robin method, to the main channel interface 4 and the one or more band-securing interface 11, and transmits the data packet to an internet network 8 through the main radio communication terminal 5 and the one or more band-securing radio communication terminals 12 to distribute the data packet to the center router device 10 as a destination.SELECTED DRAWING: Figure 1

Description

The present invention relates to a media adapter device, a distributed communication management method, and a distributed communication management program. For example, the present invention is for use as an in-house network (IPsec-VPN) in small-to-medium-sized bases using wireless communication, or for securing a temporary detour path in a base for using a wired in-house network after a disaster occurs, or in-house The present invention relates to a media adapter device, a distributed communication management method, and a distributed communication management program that can be suitably applied for widening the bandwidth of a bypass route in a network and for adding a temporary bypass route.

In a network system in which a device connected to a LAN (Local Area Network) is connected to an Internet network via a wireless line, Japanese Patent Laid-Open No. 2016-167751 “Communication control system, communication control method, and communication control” As described in “Program”, a state in which a router device for routing control connected to a LAN and a wireless communication terminal connected to the Internet network can communicate with each other by a media adapter device that performs media conversion processing. It is connected to the. The media adapter device has a function of converting the communication media from the LAN signal format to the wireless signal format or from the wireless signal format to the LAN signal format.

The connection configuration of the current media adapter device will be further described with reference to FIG. FIG. 11 is a connection configuration diagram showing the connection configuration of the current media adapter device.

As shown in FIG. 11, the LAN side of the media adapter device 3 is connected to the router device 1 via a LAN cable 2. A main wireless communication terminal 5 is connected to a WAN (Wide Area Network) side main line interface 4 (connector) of the media adapter device 3. The case where only one main wireless communication terminal 5 is shown is shown, and the media adapter device 3 converts the data transmitted from the router device 1 via the LAN cable 2 into a wireless signal format, and the main line Output to the main wireless communication terminal 5 via the communication interface 4.

Then, the main radio communication terminal 5 transmits the received radio signal to the center router device 10 connected to the Internet network 8 via the main radio line 6 and the radio line carrier network 7. Here, the media adapter device 3 can also connect a plurality of main wireless communication terminals 5 for working and protection, and depending on the communication state, the main wireless communication terminal for the protection side rather than the working side transmits wireless signals. It is also possible to output to 5.

However, the current media adapter device 3 has the following problems.

The first problem is that the media adapter device 3 is regarded as an accessory to the router device 1 when viewed from the router device 1, and thus is not treated as a management target and is normally not set for management. .. Therefore, if the maintenance of the media adapter device 3 is to be performed as a communication device, it is necessary to dispatch personnel to the site when adding/changing the setting for management, which requires man-hours and labor.

The second problem is that the router device 1 subordinate to the media adapter device 3 is a device that is physically located at a position different from the main wireless communication terminal 5. For this reason, the router device 1 cannot recognize the connection state of the main wireless line 6 with the wireless line carrier network 7 or the state of the wireless band. It cannot be detected. Therefore, even if such a communication abnormality occurs, only traffic control such as retransmission in the upper layer can be performed.

The third problem is that, as the current line service of the main wireless communication terminal 5, there are specifications for automatically narrowing the wireless band according to the usage amount and a metered service, but as described above, the router device 1 This is because the communication band of the main wireless line 6 and the like and the state of traffic cannot be detected, and traffic backup cannot be performed on the infrastructure. For this reason, normal upper-layer protocol control between wireless communication terminals is performed, but in such a case, retransmissions increase and duplicate packets and discard packets increase in the wireless carrier network 7. I will end up. Therefore, unnecessary line cost increases and the signal response to be transmitted/received is affected.

JP, 2016-167751, A

As described above, in the network system using the current media adapter device related to the present invention, the communication device under the media adapter device such as the router device which is not directly connected to the wireless line is the band of the wireless line. Can't recognize. For this reason, there is a problem in that data is transmitted using the communication speed and communication state most recently used as it is, and a buffer overflow occurs in the media adapter device, the wireless communication terminal, or the like. Particularly, in the case of a media adapter device to which a communication device such as a media adapter device or a small router device to which a communication line having a narrow wireless band is connected for connection with the Internet network is connected, the media adapter device or the router device, etc. In such communication devices, there are frequent communication abnormalities that cause buffer overflow.

Further, in a media adapter device having only a simple media conversion function, since one-to-one media conversion is performed with a wireless communication terminal connected only one as an active terminal used for actual communication, The operation of the media adapter device is limited by the state and communication speed of the wireless communication terminal. Even if a shortage of the wireless band occurs, it cannot be solved within the media adapter device. Therefore, the support is the function of the communication device such as the router device connected to the LAN side of the media adapter device or the upper layer. There is no choice but to rely on the delay/retransmission mechanism in the upper layer based on the IPsec (Security Architecture for Internet Protocol) protocol, which is the above-mentioned encryption technology.

Furthermore, in the normal IPsec protocol, when traffic increases at the interface between end-to-end communication terminals, packet non-delivery occurs, and packet retransmission by the upper layer occurs. appear. However, for example, in an environment where high-speed interfaces and low-speed interfaces coexist, even when trying to avoid packet non-delivery that occurs on the high-speed interface side, it is possible to effectively utilize the communication band of the low-speed interface. could not.

In addition, large-scale carrier grade NAT (CGN: Carrier Grade NAT (Network Address Translator)) and IPv6 (Internet Protocol Version 6) have come to be used depending on recent wireless communication terminals. It is becoming necessary to adopt a corresponding router device, add functions to existing router devices, or add a new router device for another path and use it for routing. ..

(Purpose of the present disclosure)
The present disclosure has been made in view of the above circumstances, and is capable of avoiding communication abnormality due to overload or failure of a wireless line, and is limited to a wireless communication carrier (line carrier). It is an object of the present invention to provide a media adapter device, a distributed communication management method, and a distributed communication management program that can reliably secure a wireless band without the occurrence of such problems.

That is, like the current media adapter device, a single connection is made from the subordinate router device connected to the LAN side to terminate at the media adapter device, and the media adapter device communicates wirelessly. By connecting multiple terminals and avoiding overload or failure of wireless communication and enabling distributed wireless communication, it is possible to ensure the wireless band when connecting to the Internet network. Is the object of the present disclosure.

Furthermore, when using multiple wireless communication terminals connected to the media adapter device, communication of wireless communication terminals that have reached the limit of communication volume without changing individual contracts (settings) with wireless network operators It is also an object of the present disclosure to automatically add a new wireless communication terminal so that communication can be performed so as to compensate for the above.

In order to solve the above problems, the media adapter device, the distributed communication management method, and the distributed communication management program according to the present invention mainly employ the following characteristic configurations.

(1) The media adapter device according to the present invention is
In a network system for connecting a router device connected to a LAN (Local Area Network) to a center router device connected to an internet network via a wireless line, for connecting the router device to the internet network via a wireless line Is a media adapter device for performing media conversion of
As an interface on the WAN (Wide Area Network) side,
A main line interface for connecting a main wireless communication terminal for transmitting and receiving radio signals relating to data flowing on the main wireless line,
One or a plurality of band securing interfaces for respectively connecting one or a plurality of band securing wireless communication terminals for securing a wireless line for securing a wireless band;
Equipped with
When a data packet addressed to the center router device is received from the router device, the data packet is subjected to media conversion, and a round robin method is used for the main line interface and one or more band securing interfaces. To the Internet network via the main wireless communication terminal and one or more of the band securing wireless communication terminals, and distributes to the destination center router device.
It is characterized by

(2) The distributed communication management method according to the present invention is
In a network system for connecting a router device connected to a LAN (Local Area Network) to a center router device connected to an internet network via a wireless line, for connecting the router device to the internet network via a wireless line Is a distributed communication management method in a media adapter device for performing media conversion of
The media adapter device is
A main line interface for connecting a main wireless communication terminal for transmitting and receiving a wireless signal relating to data flowing on a main wireless line, and one or a plurality of band securing wireless communication terminals for securing a wireless band for securing a wireless band. A step of transmitting and receiving data via each of one or a plurality of bandwidth securing interfaces connecting the respective,
Have
When a data packet addressed to the center router device is received from the router device, the data packet is subjected to media conversion, and a round robin method is used for the main line interface and one or more band securing interfaces. To the Internet network via the main wireless communication terminal and one or more of the band securing wireless communication terminals, and distributes to the destination center router device.
It is characterized by

(3) The distributed communication management program according to the present invention is
In a network system for connecting a router device connected to a LAN (Local Area Network) to a center router device connected to an internet network via a wireless line, for connecting the router device to the internet network via a wireless line Is a distributed communication management program executed by a computer in a media adapter device for performing media conversion of
The media adapter device is
A main line interface for connecting a main wireless communication terminal for transmitting and receiving a wireless signal relating to data flowing on a main wireless line, and one or a plurality of band securing wireless communication terminals for securing a wireless band for securing a wireless band. A function for transmitting and receiving data via each of one or a plurality of bandwidth securing interfaces that connect the respective
Have
When a data packet addressed to the center router device is received from the router device, the data packet is subjected to media conversion, and a round robin method is used for the main line interface and one or more band securing interfaces. To the Internet network via the main wireless communication terminal and one or more of the band securing wireless communication terminals, and distributes to the destination center router device.
It is characterized by

According to the media adapter device, the distributed communication management method, and the distributed communication management program of the present invention, the following effects can be mainly achieved.

By using multiple wireless communication terminals in sequence in the round-robin method, it is not necessary to rely on the service function provided by the wireless network operator, and the contracted capacity of each wireless communication terminal can be used as it is. Can be secured.

It is a connection block diagram which shows an example of the connection structure of the media adapter apparatus which concerns on this invention. It is explanatory drawing explaining the mode that the media adapter apparatus of FIG. 1 expands and secures the wireless band for communication with a center router apparatus using a wireless communication terminal for band securing. FIG. 3 is an explanatory diagram for explaining an example of the operation of the media adapter device shown in FIGS. 1 and 2. 3 is a sequence chart showing an example of an operation flow from a connection process to a band securing communication process in the media adapter device shown in FIG. 1. 3 is a sequence chart showing an example of an operation flow from IPsec management communication to data communication by TCP communication in the media adapter device shown in FIG. 1. 3 is a table showing an example of a data format relating to band securing data transferred on each band securing interface of the media adapter device shown in FIG. 1. 3 is a table showing an example of a data format relating to IPsec management communication data transferred on the main line interface of the media adapter device shown in FIG. 1. 7 is a flowchart showing an example of an operation of monitoring TCP communication of a band securing interface in the media adapter device shown in FIG. 1. 8 is a flowchart showing an example of an operation of performing monitor reception of TCP communication via a band securing interface in the center router device shown in FIG. 1. FIG. 3 is a connection configuration diagram showing an example different from FIGS. 1 and 2 of the connection configuration of the media adapter device according to the present invention. It is a connection block diagram which shows the connection structure of the present media adapter apparatus.

Hereinafter, preferred embodiments of a media adapter device, a distributed communication management method, and a distributed communication management program according to the present invention will be described with reference to the accompanying drawings. In the following description, the media adapter device and the distributed communication management method according to the present invention will be described, but the distributed communication management method may be implemented as a distributed communication management program executable by a computer, or Needless to say, the distributed communication management program may be recorded in a computer-readable recording medium. Further, the drawing reference symbols attached to the following drawings are added for convenience to each element as an example for helping understanding, and it goes without saying that the present invention is not intended to be limited to the illustrated modes. Yes.

(Basic Embodiment of the Present Invention)
Prior to the description of the embodiments of the present invention, the outline of the basic embodiments of the present invention will be described first. The basic embodiment of the present invention relates to a media adapter device for media conversion for connecting to an Internet network using a wireless line, and for giving the media adapter device a function of securing a wireless band. In addition, when a router device connected to a plurality of wireless communication terminals and connected under the media adapter device performs IPsec communication, the plurality of wireless communication terminals can be sequentially operated by a round robin method without changing settings. By using it, it is possible to connect to multiple wireless lines and secure the bandwidth of the wireless interface.

Further, regardless of which protocol, IPv4/IPv6 protocol, is used for the wireless line, the main feature is that the wireless band can be secured in the IPsec communication under the environment of the dynamic address acquisition. ..

More specifically, according to the basic embodiment of the present invention, a plurality of wireless communication terminals are connected to the media adapter device, one of the wireless communication terminals is used as a main wireless communication terminal for the main line, and the remaining wireless communication terminals are used. The terminal is a band securing wireless communication terminal for securing a wireless band. Then, in accordance with the operation of connecting the main wireless communication terminal to the main wireless line, each band securing wireless communication terminal also performs an operation of connecting to the band securing wireless line in advance, and determines the address to be used in each wireless communication. Get it.

Then, when a data packet transmission operation (IPsec communication) is started from the router device under the media adapter device to the destination center router device via the Internet network via the main line, the media is triggered by the operation. The adapter device acquires the communication port number designated by the center router device on the partner side by performing management communication between the router device and the center router device. Then, the media adapter device connects to the center router device of the other party via each of the plurality of wireless communication terminals using the designated communication port number. As a result, the data packet to be transmitted to the center router device on the partner side can be sequentially distributed to a plurality of wireless lines by the round robin method and used, and the wireless band can be secured.

In addition, the media adapter device also makes it possible to grasp the communication status of each wireless line by monitoring the communication status between the plurality of connected wireless communication terminals and the partner center router device. There is. When the disconnection of the communication path via any wireless line is detected as the monitoring result, the wireless communication terminal can be reset and reconnected to perform the recovery operation of the wireless line. become. Thus, the influence of communication interruption can be minimized, and the wireless band can be automatically maintained.

Further, in the media adapter device, the connection of the IPsec communication is performed by the main line, but as described above, the data packet is sequentially transmitted to each wireless communication terminal by the round robin method including the line for securing the other band. By allocating, it operates so as to minimize the delay of the transfer process. At this time, in order to authenticate that the other band securing line connection is correct, the IP address information etc. exchanged when each band securing wireless communication terminal connects with the center router device on the opposite side is used. It is sent as authentication information (that is, communication management information) to the center router device using the line. Also, when the wireless communication terminal is reconnected after the line is disconnected, the updated IP address information and the like are sent to the center router device. By performing such an operation, it is possible to improve the reliability of connection of a line for securing a band other than the main line.

That is, in the center router device on the opposite side, in addition to the information on the establishment of the IPsec connection of the main line from the media adapter device, the line information of the connection from the other wireless communication terminal for band amplification is acquired and the main line communication is performed. Confirm the connection for securing bandwidth other than the above. Then, the center router device on the opposite side notifies the wireless communication terminal for securing the band of the connection port number (TCP port number) for TCP communication, and the connection is established by the TCP communication using the TCP port number. maintain. As for the wireless line between the media adapter device and the center router device on the opposite side, a wireless line for band securing can be used together as a band for IPsec communication of the main line, and the band is secured. It is possible to carry out IPsec communication.

Here, the media adapter device uses the TCP port number obtained from the center router device for the data packet destined for the bandwidth securing wireless line among the data packets received as the IPsec communication from the subordinate router device. A TCP header is created, TCP encapsulation is performed, and the created TCP packet is sent to the center router device on the opposite side via the corresponding band-securing wireless communication terminal. Therefore, even in the case of communication that is separated and connected by the round robin method, it is possible to secure the facing of the communication.

Further, the center router device confirms the TCP port number and IP address of the TCP packet sent from the wireless communication terminal for band securing, and performs the authentication process. Then, when the authentication is obtained, the TCP capsule of the TCP packet is released, and then the packet is delivered to the processing unit that processes the data packet in the IPsec communication (IPsec connection) of the main line. Then, the center router device confirms the status of the TCP connection for band securing from the reception state of the sent TCP packet, and sends the response to the TCP packet to the reply destination. By operating as described above, it is possible to communicate with one connection without connecting a plurality of IPsec communication connections.

It should be noted that the wireless communication terminals that are connected to a plurality of media adapter devices may use carrier grade NAT (CGN) depending on the contract content and wireless network operator. Therefore, it is necessary to confirm whether or not the NAT conversion is performed at the first connection with the center router device on the opposite side. For example, when used as a band securing wireless communication terminal, it is necessary to perform communication using a unique protocol in which IP addresses of a source/destination are registered when starting TCP communication of a designated TCP port number. is there. In the TCP communication, data is exchanged by designating and transmitting a keepalive for maintaining a communication path as a parameter for communication for bandwidth reservation management, and maintaining a NAT-converted address in a cache. You can

Further, when the IPv6 address is used as the contract for the wireless communication terminal, the IPv6 address is registered in advance also in the opposite center router device, and the IPv6 address is also used as the unique protocol of the TCP communication at the time of the band securing connection. By making the correspondence, TCP encapsulation can be performed even when the TCP connection of the wireless communication terminal is the IPv6 protocol. Therefore, for example, even if the IPsec communication of the main line connection is the IPv4 protocol, the communication can be performed regardless of the relationship.

It should be noted that the router device under the media adapter device does not need to consider the limit of the number of connections for IPsec communication or the route control in the case of a plurality of connections. Since it is connected as, the setting can be simplified, and the operation such as the failure investigation and the setting change can be made efficient.

(Example of Configuration of Embodiment of the Present Invention)
Next, one embodiment of the connection configuration of the media adapter device according to the present invention will be described with reference to FIG. FIG. 1 is a connection configuration diagram showing an example of a connection configuration of a media adapter device according to the present invention.

That is, as shown in FIG. 1, as in the case of FIG. 11 showing the connection configuration of the current media adapter device, a LAN cable of Ethernet (Gigabit/s, 100 Mbit/s, etc.) is provided on the LAN side of the media adapter device 3. The router device 1 is connected via 2. A main wireless communication terminal 5 is connected to a WAN-side main line interface 4 (connector) of the media adapter device 3, and the wireless line carrier network 7 is connected from the main wireless communication terminal 5 through a main wireless line 6. It is connected to the Internet network 8 via. A center router device 10, which is a partner of the router device 1, is connected to the Internet network 8.

However, unlike FIG. 11, in FIG. 1, the WAN side of the media adapter device 3 is further provided with one or a plurality of band securing interfaces 11 in addition to the main line interface 4. One or a plurality of band securing wireless communication terminals 12 are connected to the one or a plurality of band securing interfaces 11, and one or a plurality of band securing wireless lines 13 are used to pass through the wireless line carrier network 7. Connected to the Internet network 8.

Here, when a connection request 301 based on PPPoE (Point-to-Point Protocol over Ethernet) is transmitted from the router device 1 connected to the LAN side of the media adapter device 3, the media adapter device 3 uses the interface for the main line. By transmitting the proxy connection request 304 via the main wireless communication terminal 5 connected to the wireless communication terminal 4, the wireless network operator network 7 accesses the Internet network 8 to acquire the IP address 303 for connection, and to request the connection. It is delivered to the router device 1 as a response 300 to 301. The router device 1 can perform the IPsec communication 302 with the Internet 8 by using the IP address 303 acquired by receiving the response 300.

Further, the media adapter device 3 transmits a proxy connection request 306 simultaneously with the activation of the media adapter device 3 through one or a plurality of band securing wireless communication terminals 12 connected to the band securing interface 11 on the WAN side. By doing so, the Internet network 8 is accessed from the access point of the wireless network carrier network 7 and the IP address 307 (or IPv6 address) for connection is acquired. The media adapter device 3 stores the acquired IP address 307 (or IPv6 address) and waits for an IPsec communication connection process from the router device 1 under the control.

Next, as the IPsec communication connection process, the router device 1 starts the IPsec communication 305 using the acquired IP address, and establishes a VPN (Virtual Private Network) connection with the center router device 10 at the opposite end. At this time, the media adapter device 3 relays communication with a port number “500” of UDP (User Datagram Protocol) in order to establish SA (Security Association) of IPsec communication. On the other hand, for the purpose of bandwidth management, the TCP port number “500” is used to exchange information of the bandwidth securing interface with the opposite center router device 10 by TCP communication 314 of a unique data format. After the information on the bandwidth securing interface is acquired, the opposite center router device 10 uses the peer destination and TCP port number of its own center router device 10 used in the TCP communication 314 for securing a different bandwidth. The Peer destination and the TCP port number are acquired and notified to the media adapter device 3 by the TCP communication 314 of the unique data format.

Next, how the media adapter device 3 shown in FIG. 1 expands and secures the wireless band by using the band securing wireless communication terminal 12 will be described with reference to FIG. FIG. 2 is an explanatory diagram illustrating how the media adapter device 3 of FIG. 1 uses the band securing wireless communication terminal 12 to expand and secure a wireless band for communication with the center router device 10.

In the explanatory view of FIG. 2, the media adapter device 3 acquires the port number for data communication as the band securing interface 11, and then, via the band securing wireless communication terminal 12 connected to the acquired port number. To the center router device 10, data communication is performed periodically at a predetermined time interval to the TCP port number previously acquired in the description of FIG. 1 as a keep-alive for keeping the line. , And maintains a state in which the band securing communication path via the band securing wireless communication terminal 12 is valid.

At that time, information is exchanged between the transmission source and the destination, and the media adapter device 3 registers the exchanged information between the transmission source and the destination in the management parameter 17. As a result, the media adapter device 3 performs TCP communication 313 (in other words, communication in which ESP packet of IPsec communication is TCP-encapsulated) performed with the center router device 10 via the band securing wireless communication terminal 12. The connection can be completed. Further, when a change occurs in the management parameter 17 related to the TCP communication 313, the media adapter device 3 transfers the update information of the management parameter 17 to the center router device 10 via the main wireless communication terminal 5. , The TCP connection with the center router device 10 can be maintained.

That is, when the information about the TCP communication 313 stored in the management parameter 17 is changed, the media adapter device 3 instructs the center router device 10 to update the management parameter so that the center router device 10 also The information stored in the management parameter 16 is updated. When the information stored in the management parameter 16 is updated, the center router device 10 returns a response for confirming the information update of the management parameter 16 to the media adapter device 3. As a result, the TCP connection regarding the TCP communication 313 with the center router device 10 can be maintained.

When the media adapter device 3 receives the data for the IPsec communication 316 from the subordinate router device 1 after receiving the response for confirming the information update from the center router device 10, the data is ESP (Encapsulating Security Payload: encapsulation). (Security payload) Check whether it is a packet. As a result of the confirmation, when it is confirmed that the data received from the subordinate router device 1 is an ESP packet, the ESP packet is sequentially distributed to a plurality of communication paths by the round robin method, and the center router device 10 Send to. That is, in order, in addition to transmitting to the center router device 10 via the main wireless communication terminal 5 for the main line, TCP communication 313 for securing a band with the center router device 10 is also used in order. Then, TCP encapsulation is performed using the designated TCP port number, and the data is transmitted to the center router device 10 via the band securing wireless communication terminal 12.

In the destination center router device 10, the IPsec data packet transmitted from the main wireless communication terminal 5 is transferred as it is to the data processing unit of the upper IPsec communication. On the other hand, regarding the data transmitted from the band securing wireless communication terminal 12, the TCP port number registered in the management parameter 16 is referred to, and the permitted IPsec data packet (that is, TCP encapsulation) from the media adapter device 3 is referred to. It is confirmed that the packet is an IPsec data packet).

When the center router device 10 confirms that the IPsec data packet is from the permitted media adapter device 3, the center router device 10 releases the TCP capsule applied to the transferred IPsec data packet, and returns to the original IP header. To an ESP packet (IPsec data packet) having Thereafter, the center router device 10 processes the data of the relevant IPsec communication in order to process the restored ESP packet for the IPsec communication 305 established as the main wireless line 6 passing through the main wireless communication terminal 5. Hand over to the department.

Further, regarding communication from the center router device 10, the destination of the band securing wireless communication terminal 12 and the destination of the main wireless communication terminal 5 of the designated TCP port number stored in the management parameter 16 are sequentially used in a round robin method. By transmitting the data to the media adapter device 3, the state in which not only the band of the wireless line with the main wireless communication terminal 5 but also the band of the wireless line of the band securing wireless communication terminal 12 is secured. maintain.

Regarding the bandwidth securing interface 11 of the media adapter device 3, the media adapter device 3 periodically sends keep alive to the center router device 10 to confirm that the communication session is continued. ing. However, when the media adapter device 3 detects that the response to the keep-alive is not returned from the center router device 10, the band securing wireless communication terminal to which the corresponding band securing wireless line is connected. By resetting 12 once and reconnecting, the operation of restoring the corresponding wireless line for band securing is performed. At this time, the media adapter device 3 performs management communication from the main line interface 4 to the center router device 10 to notify that the reconnection is in progress.

Further, when the keep-alive from the bandwidth securing interface 11 of the media adapter device 3 does not arrive at the opposite center router device 10, or when the notification indicating that the reconnection is being received from the main line interface 4, The data transmission operation of the TCP communication 313 related to the corresponding band securing wireless line is skipped, and the operation of transmitting the data via another TCP connection in the next order is performed. After that, when a keep-alive via the corresponding band securing wireless communication terminal 12 arrives or a reconnection completion notice (connection notice) arrives, the band securing radio line is related. The data transmission operation via the TCP communication 313 is restarted.

As described above, the media adapter device 3 transmits the data packet of the IPsec communication from the subordinate router device 1 to the plurality of wireless communication terminals (the main wireless communication terminal 5 and the one or more band securing wireless communication terminals 12). Using the round robin method to sequentially transmit through the main line interface 4 and one or a plurality of band securing interfaces 11, it is possible to widen the wireless band with one connection and secure the wireless band. The function of doing is realized.

As described above, the media adapter device 3 causes the wireless network carrier network to periodically transmit a keepalive for keeping the communication path effective from each band securing interface 11. The state of the communication path for securing the bandwidth of No. 7 is monitored. Then, the media adapter device 3 determines whether or not the data can be transmitted through each band securing interface 11 from the monitor result, and skips the data transmission using the band securing interface 11 corresponding to the untransmittable state. , It is possible to reduce the data retransmission processing in the upper layer.

Further, the media adapter device 3 uses the communication management information relating to the communication via each of the one or a plurality of bandwidth securing interfaces 11 as IPsec management communication via the main line interface 4 to the center router device 10 on the opposite side. To the management parameter 16 in the center router device 10 to perform registration.

Therefore, in the center router device 10 on the opposite side, by using the IPsec management communication from the media adapter device 3 via the main wireless communication terminal 5, the confirmation information of the TCP communication of the bandwidth securing interface 11 is acquired, It realizes the function of performing TCP connection processing with the bandwidth securing interface 11 and bandwidth securing by registering in the management parameter 16. Then, the center router device 10 selects the data transmission operation by receiving the status notification by the keep-alive or the management communication from the media adapter device 3, reduces the data retransmission process in the upper layer, and can secure the wireless band. I have to.

(Description of Operation of Embodiment)
Next, the operation of the media adapter device 3 shown in FIGS. 1 and 2 as an embodiment of the present invention will be described in detail with reference to FIG. FIG. 3 is an explanatory diagram for explaining an example of the operation of the media adapter device 3 shown in FIGS. 1 and 2. Transfer of a data packet between the subordinate router device 1 and the facing center router device 10. An example of the operation is shown. Regarding the reference numerals given to the signals transmitted and received between the respective devices, the same signals as the signals in FIGS. 1 and 2 are indicated by the same reference numerals.

In FIG. 3, the LAN side of the media adapter device 3 is connected to the router device 1 through a LAN cable 2 of Ethernet (Gigabit/s, 100 Mbit/s, etc.) used in LAN communication as shown in FIG. ing. On the WAN side of the media adapter device 3, a main wireless communication terminal 5 is connected to a main line interface 4, and one or more band securing interfaces 11 are provided with one or more band securing wireless communications. The terminal 12 is connected.

Then, when the connection request 301 by PPPoE is transmitted from the router device 1 based on the communication setting information set in the router setting parameter 18, the media adapter device 3 causes the main wireless communication connected to the main line interface 4. By transmitting the proxy connection request 304 via the terminal 5 and the main wireless line 6, the access point of the wireless line carrier network 7 accesses the Internet network 8 to acquire the IP address 303.

Then, the media adapter device 3 returns the acquired IP address to the router device 1 which is the transmission source of the connection request 301 as a response 300 to the connection request 301. As a result, the router apparatus 1 can access the Internet network 8 via the media adapter apparatus 3, the main wireless communication terminal 5, and the wireless network operator network 7, and the IPsec communication 302 with the Internet network 8 is performed. Is ready to do.

In the description of FIG. 3, it is assumed that the media adapter device 3 includes four band securing interfaces 11 and can connect four band securing wireless communication terminals 12. Then, at the same time when the media adapter device 3 is started up, the media adapter device 3 sends a proxy connection request 306 via each of the four band securing wireless communication terminals 12 connected to the band securing interface 11 on the WAN side. The IP address 307 (or IPv6 address) is acquired by transmitting to the access point of the wireless network carrier network 7 to access the Internet network 8. The media adapter device 3 registers the acquired IP address 307 (or IPv6 address) in the management parameter 17 and waits for an IPsec communication connection process from the router device 1 under the control.

After that, the router device 1 performs the VPN connection with the opposite center router device 10 by the IPsec communication 305 using the previously acquired IP address as the IPsec communication connection process. At that time, the media adapter device 3 relays communication of the port number '500' of UDP (User Datagram Protocol) used for SA (Security Association) establishment. As the communication for communication, the TCP port number “500” is used to perform the TCP communication 314 of the unique data format (that is, the data format using the dedicated protocol for the upper layer) with the opposite center router device 10. , And exchanges information about the band securing interface 11.

In the present embodiment, as the unique data format used for the TCP communication 314, information regarding the bandwidth securing interface 11 (that is, information such as an IP address (or IPv6 address) and a bandwidth securing host name (hostname)) is set to 8. It shall be possible to install up to the number of units.

When the media adapter device 3 acquires the information about the bandwidth ensuring interface 11 by the TCP communication 314, the media adapter device 3 registers and saves it in the management parameter 17, and creates a packet storing the acquired information about the bandwidth ensuring interface 11, By the TCP communication 314 using the unique data format, it is sent to the opposite center router device 10 as temporary information of the band securing interface.

The opposite center router device 10 registers and saves in the management parameter 16 the information about the bandwidth securing interface 11 sent as temporary information of the bandwidth securing interface from the media adapter device 3. After that, the center router device 10 acquires the Peer destination for securing the band and the TCP port number of the center router device 10. That is, in the TCP communication 314, a Peer destination different from the Peer destination of the own center router device 10 designated as the destination from the media adapter device 3 (there may be a Peer destination composed of an IPv6 address of a different protocol) and a band. The TCP port number used in data communication via the securing interface 11 is acquired.

Then, the center router device 10 notifies the media adapter device 3 of the acquired Peer destination for band securing and the TCP port number of the own center router device 10 by the TCP communication 314 of the unique data format. When the media adapter device 3 receives the Peer destination for band securing and the TCP port number of the center router device 10 notified from the center router device 10, the media adapter device 3 registers and saves it in the management parameter 17.

Then, when the media adapter device 3 transmits data to the center router device 10, if the communication paths of the band securing interface 11 are in order by the round robin method, the media adapter device 3 starts transmitting from the center router device 10. A data packet destined to the corresponding TCP port number is created from the acquired TCP port numbers, and the TCP communication 313 addressed to the TCP port number of the center router device 10 (in other words, via the bandwidth securing interface 11). And ESP packet of IPsec communication are encapsulated in TCP).

Further, the media adapter device 3 uses the dedicated protocol to communicate with the center router device 10 by using TCP communication 313 including the IP address or IPv6 address of the source and the destination as keep alive. In order to maintain the connection for data communication for bandwidth reservation, we periodically exchange the data and confirm that the communication path for bandwidth reservation is valid. At this time, when NAT conversion is performed from the center router device 10 by a path such as carrier grade NAT (CGN), information including the IP address or IPv6 address of the source and destination after NAT conversion is exchanged. ..

Further, when there is a change in the management parameter 17 related to the TCP communication 313 addressed to the corresponding TCP port number of the center router device 10 via the band securing interface 11, the media adapter device 3 changes the management parameter 17. Information is notified to the center router device 10 by TCP communication 314 via the main line interface 4. Upon receiving the information on the changed management parameter 17 from the media adapter device 3, the center router device 10 updates the information stored in the management parameter 16. When the information stored in the management parameter 16 is updated, the center router device 10 returns a response for confirming the information update of the management parameter 16 to the media adapter device 3.

When the media adapter device 3 receives the data for confirming the information update from the center router device 10 and then receives the data of the IPsec communication 316 from the subordinate router device 1, the data is ESP (Encapsulating Security Payload: encapsulation). (Security payload) Check whether it is a packet. As a result of the confirmation, when it is confirmed that the data received from the router device 1 under the control is an ESP packet, the ESP packet is sequentially processed from the main line interface 4 to the main wireless interface as an IPsec data packet by the round robin method. IPsec communication 312 or TCP to the center router device 10 via the communication terminal 5 or via one or a plurality of band securing interfaces 11 and one or a plurality of band securing wireless communication terminals 12, respectively. It is transmitted by communication 413.

That is, when the ESP packet is transmitted via the main line interface 4 and the main wireless communication terminal 5, the ESP packet is transmitted to the center router device 10 by IPsec communication 312 as an IPsec data packet. On the other hand, when the ESP packet is transmitted via the bandwidth securing interface 11 and the bandwidth securing wireless communication terminal 12, it is designated as the bandwidth securing TCP communication 313 with the center router device 10 before sending. TCP encapsulation is performed using the TCP port number that is set, and then the data is sequentially transmitted to the center router device 10 by TCP communication 313.

In the destination center router device 10, different processing is performed for the IPsec data packet transmitted from the main wireless communication terminal 5 and the TCP encapsulated IPsec data packet transmitted from the band securing wireless communication terminal 12. That is, the IPsec data packet transmitted from the main wireless communication terminal 5 is transferred to the upper layer IPsec communication data processing unit as it is. On the other hand, regarding the TCP encapsulated IPsec data packet transmitted from the band securing wireless communication terminal 12, first, the management parameter 16 and the TCP port number are referred to, and the TCP encapsulated IPsec from the permitted media adapter device 3 is referred to. Check if it is a data packet.

Then, when confirming that the TCP encapsulated IPsec data packet from the permitted media adapter device 3 is received, the center router device 10 releases the TCP capsule applied to the transmitted TCP encapsulated IPsec data packet. And restores the IPsec data packet (ESP packet) having the original IP header. Thereafter, the center router device 10 performs the same process as the process of the restored IPsec data packet (ESP packet) by the IPsec communication 305 that passes through the main line interface 4 and the main wireless communication terminal 5. In order to do so, the data is passed to the relevant IPsec communication data processing unit in the upper layer.

On the other hand, regarding communication in which data is transmitted from the center router device 10 to the router device 1, the destination of the router device 1 via the main wireless communication terminal 5 and the TCP port number stored for bandwidth reservation in the management parameter 16 are used. The wireless band is secured by sequentially transmitting to the destination of the band securing wireless communication terminal 12 by the round robin method. Here, regarding the bandwidth securing line, as described above, the media adapter device 3 sends the communication management information relating to the communication via each of the one or a plurality of bandwidth securing interfaces 11 via the main line interface 4. , And is registered as a management parameter 16 in the center router device 10 by being transmitted to the opposite center router device 10.

Therefore, when transmitting the data packet addressed to the router device 1, for example, from the center router device 10, the center router device 10 refers to the management parameter 16 to execute the data packet addressed to the router device 1 by the main round robin method. A wireless band can be secured by sequentially allocating to the wireless communication terminal 5 and one or a plurality of band securing wireless communication terminals 12 and transmitting them in a distributed manner. As a result, when the media adapter device 3 detects the data packets sequentially transmitted through the main line interface 4 and the one or more band securing interfaces 11, it secures one or more band securing bands. The data packet transmitted via each of the wireless communication terminal 12 and the band securing interface 11 is associated with the data packet transmitted via the main wireless communication terminal 5 and the main line interface 4, It can be delivered to the router device 1.

Regarding the IPsec management communication such as a rekey for periodically updating the key for encryption and a keepalive for keeping alive of the bandwidth securing interface 11, a media adapter device 3 and a center router device are used. 10 communicates with each other through the IPsec communication 312 via the main line interface 4, and the media adapter device 3 and the subordinate router device 1 communicate with each other through the IPsec communication 316.

Next, the above operation will be further described with reference to the sequence chart of FIG. FIG. 4 is a sequence chart showing an example of the flow of operations from the connection processing to the bandwidth securing communication processing in the media adapter device 3 shown in FIG. 1. The router device 1 under the media adapter device 3 and the media An example of an operation flow in each of the adapter device 3, the main wireless communication terminal 5, the band securing wireless communication terminal 12, the wireless network operator network 7, and the center router device 10 is shown.

First, the subordinate router device 1 performs an operation of registering an authentication IP address by PPPoE, starts a connection operation with the internet network 8, and sends a parameter to the media adapter device 3 (that is, a parameter for requesting a connection with the internet network 8). ) Is sent (sequence Seq51), the media adapter device 3 acts on behalf of the connection request with the Internet 8 (sequence Seq52), and sends an IP address acquisition request to the main wireless communication terminal 5 (sequence Seq53).

Upon receiving the IP address acquisition request, the main wireless communication terminal 5 establishes a wireless connection with the wireless network operator network 7 and transfers the IP address acquisition request (sequence Seq54). Upon receiving the IP address acquisition request, the wireless network operator network 7 connects to the Internet network 8 and acquires the IP address. The acquired IP address is sequentially returned from the wireless network carrier network 7 to the main wireless communication terminal 5 and the media adapter device 3, and finally from the media adapter device 3 to the router device 1.

After registering the returned IP address, the router device 1 uses the IP address to establish an IPsec connection with the Internet network 8 to perform the IPsec communication (UDP/ESP) from the router device 1. Then, an IPsec communication connection process such as a rekey process is started (sequence Seq55).

On the other hand, when the connection IP address of the Internet network 8 is returned from the main wireless communication terminal 5, the media adapter device 3 registers the IP address as the management parameter 17 (sequence Seq59), and the IPsec in the router device 1 is set. At a timing earlier than the start of the communication connection process, the band securing interface 11 transmits a band securing wireless connection authentication request to the band securing wireless communication terminal 12. Upon receiving the wireless connection authentication request, the band securing wireless communication terminal 12 performs a process of transferring to the wireless network operator network 7 (sequence Seq60). When the wireless network operator network 7 receives the wireless connection authentication request, it performs wireless connection authentication, accesses the Internet network 8, and acquires a connection IP address. Then, the wireless line carrier network 7 notifies the media adapter device 3 of the connection IP address acquired from the Internet network 8 via the band securing wireless communication terminal 12 (sequence Seq61). The media adapter device 3 registers the notified connection IP address in the management parameter 17 as communication management data for the bandwidth securing interface 11.

As a result, the connection between the bandwidth securing interface 11 of the media adapter device 3 and the Internet 8 is completed, so that the media adapter device 3 waits for the start of the IPsec communication connection process from the router device 1 under the control.

When the subordinate router device 1 starts the IPsec communication connection process for the IPsec management communication such as the IPsec communication (UDP/ESP) and the rekey process (sequence Seq55), the media adapter device 3 receives the received IPsec communication. A process of transferring the processing content (that is, the content of the IPsec communication connection processing) to the main wireless communication terminal 5 is performed (sequence Seq56). The main wireless communication terminal 5 further transfers the received processing content of the IPsec communication to the center router device 10 on the opposite side via the wireless network carrier network 7 and the Internet network 8 (sequence Seq57). .. The center router device 10 on the opposite side is used for IPsec management communication such as IPsec communication (UDP/ESP) and rekey processing according to the transferred processing content of the IPsec communication (that is, the content of the IPsec communication connection processing). Is performed (sequence Seq58).

At the same time, the media adapter device 3 performs, for example, TCP communication with a TCP port number of “500” to the main wireless communication terminal 5 as management communication for securing a band with the center router device 10 on the opposite side. Notification of a host name including a securing wireless communication interface, a wireless communication terminal, an IP address, etc. is performed (sequence Seq62). The main wireless communication terminal 5 performs a process of transferring the received TCP communication contents to the center router device 10 on the opposite side via the wireless network carrier network 7 and the Internet network 8 (sequence Seq63). The center router device 10 on the opposite side reads out the contents of the transferred TCP communication and performs a process of registering a host name including a wireless communication interface for band securing, a wireless communication terminal, an IP address, etc. in the management parameter 16. (Sequence Seq64).

Further, the center router device 10 uses a TCP port number designated for bandwidth reservation and an IP address (IPV4 address or IPv6 address) for IPsec communication previously reserved for management communication for bandwidth reservation with the media adapter device 3 on the opposite side. Address), a peer address different from the IPsec communication connection packet is returned back to the media adapter device 3 via the Internet network 8, the wireless network carrier network 7, and the main wireless communication terminal 5. Here, as the peer address, an IPv6 address is used if the IPsec communication connection packet is IPv4, and an IPv4 address is used if the IPsec communication connection packet is IPv6. The media adapter device 3 performs a process of acquiring the TCP port number for securing the band and the peer address returned from the center router device 10 and registering it in the management parameter 17 (sequence Seq62).

When the media adapter device 3 acquires the TCP port number and the peer address of the TCP communication for band securing from the center router device 10, the media adapter device 3 makes a contract for each band securing wireless communication terminal 12 via each band securing interface 11. TCP communication using a designated port number that designates the peer address of the IPv4 address or the IPv6 address as the destination, and the obtained IPv4 address or IPv6 address and the host to each band securing wireless communication terminal 12 are performed. The first name is notified again (sequence Seq65). Each band securing wireless communication terminal 12 performs a process of transferring the received TCP communication contents to the center router device 10 on the opposite side via the wireless carrier network 7 and the Internet network 8 (sequence Seq66). .. The center router device 10 on the opposite side acquires the contents of the transferred TCP communication and performs a process of registering the IPv4 address or the IPv6 address and the host name in the management parameter 16 according to the acquired contents of the TCP communication. (Sequence Seq67).

Further, when the center router device 10 confirms from the acquired TCP communication content that the communication of the band securing wireless communication terminal 12 is NAT converted, the center router device 10 acquires the IP address after NAT conversion. Then, the obtained NAT-converted IP address is sent back as a TCP communication to the media adapter device 3 via the Internet network 8, the wireless network carrier network 7, and the band securing wireless communication terminal 12.

Upon receiving the notification by the TCP communication of the designated port number, the media adapter device 3 confirms whether or not the NAT-converted IP address is attached to the notification. When the NAT-converted IP address is attached, the information of the IP address after NAT conversion is registered in the management parameter 17, and the TCP communication via the main line interface 4 and the main wireless communication terminal 5 is performed again. Then, the center router device 10 is notified of the confirmation indicating that the IP address after NAT conversion is received (sequence Seq62).

Upon receiving the confirmation notification from the media adapter device 3 by TCP communication, the center router device 10 again notifies the media adapter device 3 that the changed information has been acquired (sequence Seq64). Upon receiving the notification again, the media adapter device 3 considers that the center router device 10 has permitted the TCP communication at the designated port for NAT conversion.

After the media adapter device 3 confirms that the ESP packet has been transmitted as IPsec communication from the router device 1 under its control after receiving the permission of the TCP communication at the designated port for NAT conversion (sequence Seq68), the round robin When the order of the method is distribution to the bandwidth securing interface 11, the ESP packet is TCP-encapsulated for TCP communication of the designated port number (sequence Seq69). Then, the media adapter device 3 distributes each TCP-encapsulated packet to each band securing interface 11 and sends it to the center router device 10 via each band securing wireless communication terminal 12 (sequence Seq 70).

When confirming that the port number and IP address of the received packet are registered, the center router device 10 releases the TCP capsule and restores the original ESP packet, and the main line that should correspond to the ESP packet. Is transferred to the peer address of the IPsec communication that has arrived via the main wireless communication terminal 5 (sequence Seq71). As a result, the same processing as the ESP packet of the IPsec communication via the main line is performed (sequence Seq72).

Next, the operation of the data communication after the IPsec communication by the IPsec management communication shown in FIG. 4 will be described in more detail with reference to the sequence chart of FIG. FIG. 5 is a sequence chart showing an example of the flow of operations from the IPsec management communication to the data communication by TCP communication in the media adapter device 3 shown in FIG. 1, and similarly to the case of FIG. An example of an operation flow in each of the subordinate router device 1, the media adapter device 3, the main wireless communication terminal 5, the band securing wireless communication terminal 12, the wireless carrier network 7, and the center router device 10 is shown.

In the sequence chart of FIG. 5, the communication from the router device 1 under the media adapter device 3 is defined as “upstream” communication, and the communication above the IPsec management communication shown in sequence Seq55 to sequence Seq58 in FIG. Indicates an operation related to “uplink” communication, and an operation related to “downlink” communication is shown below the IPsec management communication. Also, for the sake of easy understanding of the description, the sequence numbers in FIG. 5 are the same as the sequence numbers given in FIG. 4 for the parts performing the same communication processing as the corresponding parts in FIG. ..

That is, the IPsec management communication of the sequence Seq55 of the router device 1, the transfer process of the sequence Seq56 of the media adapter device 3, the TCP encapsulation process of the sequence Seq69, the transfer process of the sequence Seq57 of the main wireless communication terminal 5, the wireless communication terminal for band securing. 12, the transfer processing of the sequence Seq70 of 12, the IPsec management communication processing of the sequence Seq58 of the center router device 10, the TCP decapsulation processing of the sequence Seq71, and the IPsec communication of the ESP packet of the sequence Seq72 are also shown in FIG. The same processing is performed as in the case.

In the sequence chart of FIG. 5, first, when the router device 1 performs processing such as SA establishment, rekeying, keepalive, etc. as IPsec management communication (sequence Seq55), as in the case of FIG. , Via the media adapter device 3, the main line interface 4, and the main wireless communication terminal 5 (sequence Seq56, sequence Seq57), the center router device 10 at the opposite end performs IPsec communication (UDP/ESP) and rekey processing. And the like for IPsec management communication (sequence Seq58). Here, a process for IPsec management communication regarding the band securing wireless communication terminal 12 is also executed.

Then, when the router device 1 transmits an ESP packet, which is data communication for “upstream” IPsec communication, to the media adapter device 3 (sequence Seq68), the media adapter device 3 sends the ESP packet to the main line interface. 4 (5 in the case of the present embodiment) and 4 (5 in the case of the present embodiment) bandwidth allocation interfaces 11 are distributed by the round robin method (sequence Seq82). .. That is, the peer destination of the IPsec SA connected from the main line interface 4 via the main wireless communication terminal 5 and each of the plurality of band securing interfaces 11 are designated as connection destinations of the band securing wireless communication terminal 12. TCP communication by port number is distributed to a plurality of established destinations.

The packet distributed to the main line interface 4 and addressed to the peer of the IPsec SA is transferred from the main line interface 4 to the main wireless communication terminal 5 (sequence Seq56), and passes through the main wireless communication terminal 5. (Sequence Seq57), it is delivered to the center router device 10. In the center router device 10, the received packet is delivered to the IPsec communication processing of the upper layer IPsec communication (sequence Seq72).

On the other hand, the packets distributed to the band securing interface 11 are TCP-encapsulated in the media adapter device 3 and then transferred from the band securing interface 11 to the band securing wireless communication terminal 12 (sequence Seq69). The data is delivered to the center router device 10 via the band securing wireless communication terminal 12 (sequence Seq70). In the center router device 10, after decapsulating the TCP capsule of the received packet and restoring the original ESP packet for IPsec communication, the IPsec communication processing addressed to the peer of the same IPsec SA as the main line interface 4 is performed. (Sequence Seq71).

Further, in the case of “downstream” communication from the center router device 10, when the center router device 10 transmits the ESP packet for the router device 1 addressed to the peer of the IPsec SA (sequence Seq77), the center router device 10: By referring to the information for the IPsec management communication registered in the management parameter 16, the ESP packet addressed to the router device 1 is the same as the packet addressed to the peer of the IPsec SA (as in the case of the “upstream” communication). In the embodiment, the packet is distributed to a plurality of packets including the packet for the TCP connection with the designated port number of 4) by the round robin method (sequence Seq83).

The packet distributed to the peer of the IPsec SA is transferred to the main wireless communication terminal 5 (sequence Seq78), and from the main wireless communication terminal 5 via the media adapter device 3 (sequence Seq76, sequence Seq75) to the peer. Is delivered to the router device 1 that has been set (sequence Seq74).

On the other hand, the packet distributed for the TCP connection with the designated port number is TCP-encapsulated in the center router device 10 and then transferred from the designated port number to the bandwidth securing wireless communication terminal 12 (sequence Seq81), and the bandwidth is secured. It is delivered to the media adapter device 3 via the securing wireless communication terminal 12 (sequence Seq80). The media adapter device 3 releases the TCP capsule from the received packet to restore the original ESP packet for IPsec communication (sequence Seq79), and then uses the same IPsec SA as the packet received from the main wireless communication terminal 5. Transfer to the router device 1 addressed to the peer (sequence Seq75).

Next, a data format relating to a dedicated protocol unique to this embodiment will be described. That is, an example of a data format relating to each of the band securing protocol transferred on each band securing interface 11 and the IPsec management communication protocol transferring on the main line interface 4 in the sequences of FIGS. explain. 6 is a table showing an example of a data format relating to band securing data transferred on each band securing interface 11 of the media adapter device 3 shown in FIG. 1, and FIG. 7 is a media adapter shown in FIG. 6 is a table showing an example of a data format related to IPsec management communication data transferred on the main line interface 4 of the device 3. 6 and 7, the case where there are four interfaces as the bandwidth securing interface 11 as described above is illustrated.

First, the data format relating to the band securing data in FIG. 6 will be described. Note that FIG. 6 shows an example of the bandwidth securing protocol header that follows the TCP header.

The first line 200 of the bandwidth securing protocol header includes a version (Version), data length, line information, keepalive designation (k), and spare. Here, the line information is 4 bits, and IPv4/IPv6 information indicating whether the acquired IP address of the main line interface 4 is IPv4/IPv6 in order from the upper bit side, the main line interface. 4. NAT conversion presence/absence information indicating presence/absence of NAT conversion regarding the acquired IP address of No. 4, IPv4/IPv6 information indicating whether the acquired IP address of the band securing interface 11 is IPv4/IPv6, the band securing interface 11 2 shows NAT conversion presence/absence information indicating the presence/absence of NAT conversion relating to the acquired IP address. For example, when the acquired IP address of the main line interface 4 is an IPv4 address and there is no NAT translation, and the acquired IP address of the bandwidth securing interface 11 is an IPv4 address and there is NAT translation. , The line information is set to '0001'.

In the second line, a port number 201 indicating a TCP port number for bandwidth reservation and a bandwidth reservation hostname 202 indicating a host name for bandwidth reservation are set.

Further, from the third line onward, there is an address section in which the acquired IP address of each of the main line interface 4 and the band securing interface 11 is set. That is, the acquired IP address of the main line interface 4 is set in the third line 203a at the beginning, and the acquired IP address of the band securing interface 11 is set in the fourth line 203b. The fifth line 203c and the sixth line 203d are lines added when the IP address of one or both of the main line interface 4 and the band securing interface 11 has been NAT converted. In the fifth line 203c, the NAT-converted IP address of the main line interface 4 is set, and in the sixth line 203d, the NAT-converted IP address of the bandwidth securing interface 11 is set. Note that the fifth line 203c and the sixth line 203d are set to "0" when the NAT conversion is not performed. Normally, the IP address after NAT conversion is a notification from the center router device 10.

Next, a data format relating to the IPsec management communication data in FIG. 7 will be described. The IPsec management communication protocol header in FIG. 7 shows a case where the four bandwidth securing interfaces 11 are provided as described above.

The first line 205 of the protocol header for IPsec management communication includes a type (TYPE), data length, line information, and spare. Here, the type (TYPE) is information indicating the type of the protocol header for IPsec management communication, and is set to all '0' at the time of the management communication for making the first notification, and the notification is made again by NAT conversion or the like. Set to "1" when performing. Further, the line information is assigned bit by bit as information for discriminating which one of the IPv4/IPv6 the acquired IP addresses of the four band securing interfaces 11 are, and further discriminates with/without NAT conversion. One bit is allocated as the information to be set. The bandwidth securing interfaces 11 are arranged in ascending order. For example, the first bandwidth securing interface 11 is an IPv4 address with NAT translation, the second IPv6 bandwidth securing interface 11 is an IPv6 address without NAT translation, and the remaining 2 If all of the band securing interfaces 11 have IPv4 addresses and no NAT translation, the line information is set to "01100000".

In the second line of the protocol header for IPsec management communication, as in the case of the protocol header for bandwidth reservation in FIG. 6, a port number 206 indicating a TCP port number for bandwidth reservation and a bandwidth indicating a host name for bandwidth reservation. Set the reserved hostname 207.

In the third and subsequent lines, there are address sections in which the acquired IP addresses (IPv4 address or IPv6 address) of the main line interface 4 and the band securing interface 11 are set. That is, the acquired IP address of the main line interface 4 is set in the head third line 208a, and the acquired IP address (IPv4 address) of the first band securing interface 11 is set in the fourth line 203b. Is set. In addition, in four lines 209 from the fifth line to the eighth line, it is assumed that the acquired IP address of the second band securing interface 11 is the IPv6 address, the second line across the four lines. The acquisition IP address of the th band securing interface 11 is set. Further, acquired IP addresses (IPv4 addresses) of the third band securing interface 11 and the fourth band securing interface 11 are set in the ninth line 208c and the tenth line 208d, respectively.

The 11th line 210 is a line added when the IP addresses acquired by the main line interface 4 and the band securing interface 11 are NAT-converted, and unlike the case of FIG. 6, the NAT conversion is performed. Only the established lines are set in order from the first line. Whether or not the line has been NAT-converted can be determined by referring to the line information in the first line 205. In the above-mentioned example, since only the first band securing interface 11 is the NAT-converted IP address (IPv4 address), the eleventh line 210 shows the first band securing interface. The IP address after NAT conversion of 11 is set.

Next, regarding the TCP communication in the bandwidth securing interface 11, an example of the operation of monitoring the communication route passing through the bandwidth securing interface 11 in each of the media adapter device 3 and the center router device 10 is shown in FIGS. This will be described using a flowchart. FIG. 8 is a flowchart showing an example of the operation of monitoring the TCP communication of the band securing interface 11 in the media adapter device 3 shown in FIG. 1. TCP communication is started in sequence Seq69 of the sequence chart of FIG. An example of the monitor operation at that time is shown. 9 is a flowchart showing an example of an operation of performing monitor reception of TCP communication via the band securing interface 11 in the center router device 10 shown in FIG. 1, and in sequence Seq71 of the sequence chart of FIG. , An example of the monitor reception operation when the reception operation of the TCP communication is started. The TCP communication monitoring operation and the monitor receiving operation operate to maintain the TCP communication connection for bandwidth reservation and to hold the NAT table during NAT conversion communication.

First, the monitor operation of the media adapter device 3 will be described with reference to the flowchart of FIG. When the TCP communication connection at the designated port of the band securing interface 11 is completed, the flowchart of FIG. 8 is activated, and the media adapter device 3 periodically keeps a keep alive at a predetermined time interval. It transmits from the designated port of the securing interface 11 to the opposite center router device 10 (step S1). Thereafter, it is monitored that the response from the center router device 10 to the transmitted keep-alive arrives via the designated port of the bandwidth securing interface 11 (step S2).

When the response arrives via the designated port of the bandwidth securing interface 11 (“Yes” in step S2), the designated port of the bandwidth securing interface 11 is in a normal state where the TCP connection is maintained. When it is determined that there is one, the process returns to step S1 and the operation of periodically transmitting the next keep alive is repeated.

On the other hand, if the response from the opposite center router device 10 is delayed and the response does not arrive even after the number of times specified in advance is exceeded (“none” in step S2), the connection is made to the specified port. A reset instruction is transmitted to the band securing wireless communication terminal 12 to reset the band securing wireless communication terminal 12 (step S3). Then, it is confirmed whether or not the band securing wireless communication terminal 12 is activated (step S4). If the band securing wireless communication terminal 12 is not activated (NG in step S4), the process returns to step S3 and the operation of resetting the band securing wireless communication terminal 12 is repeated again.

If it is confirmed that the band securing wireless communication terminal 12 has started up (OK in step S4), the IP address or IPv6 address obtained by re-accessing the Internet network 8 from the band securing wireless communication terminal 12 is acquired. Is returned (step S5). If the acquired IP address or IPv6 address has not been returned (NG in step S5), the process returns to step S3, and the band securing is performed again. The operation of resetting the wireless communication terminal 12 is repeated.

On the other hand, when the acquired IP address or IPv6 address is returned (OK in step S5), it is considered that the normal TCP communication is possible, and the band securing interface 11 is designated. The state shifts to a state of waiting for a TCP connection process for performing TCP communication at the port. Then, when the TCP communication connection is performed at the designated port of the bandwidth securing interface 11 (step S6), the process returns to step S1 and the next keepalive is performed from the designated port of the bandwidth securing interface 11. ) Is periodically restarted.

As the keep-alive data format, for example, the data length of the first line 200 of the bandwidth securing protocol header shown in FIG. 6 and appropriate data corresponding to the line information are set, and the 20th bit is set. Set the keep alive designation (k) to "1" and set the information corresponding to each of the port number 201 and the band securing hostname 202 on the second line, and delete the address setting fields on the third and subsequent lines. The data format of the specified format is used.

Next, the monitor receiving operation in the center router device 10 at the opposite side of the media adapter device 3 will be described using the flowchart of FIG. In the present embodiment, the center router device 10 on the opposite side of the media adapter device 3 performs only the keep-alive reception operation for monitoring and the transmission operation in order to reduce the processing load of the center router device 10. Describes the case not to do. However, the present invention is not limited to such a case, and it goes without saying that the center router device 10 may also perform an operation of transmitting a keep alive to the media adapter device 3.

When the keep-alive is received from the band securing interface 11 of the media adapter device 3 (step S11), the number of keep-alives received is counted up, and whether or not the keep-alive has been received a designated number of times within a designated time specified in advance. It is confirmed (step S12). When the keep-alives for the designated number of times are received within the designated time (“Yes” in step S12), the keep-alive transmission source media adapter device 3 is passed through the corresponding band securing interface 11. Then, a response indicating that the keep-alive is received is returned, the process returns to step S11, and the operation of receiving the next keep-alive is repeated.

On the other hand, when the keep-alive for the designated number of times is not received within the designated time (“None” in step S12), the TCP communication of the corresponding band securing interface 11 is temporarily disconnected (step S13). Then, when the confirmation of reconnection of the TCP communication of the band securing interface 11 is obtained by the TCP communication of the port number "500" from the main wireless communication terminal 5 connected to the main line interface 4 (step S14). ), and returns to step S11 to restart the operation of receiving the next keep-alive.

(Explanation of effects of this embodiment)
As described in detail above, in this embodiment, the following effects can be obtained.

The first effect is that even if the wireless communication terminal has a narrow band, it is not necessary to rely on the service function provided by the wireless network operator by sequentially using the plurality of wireless communication terminals in the round robin method. It is possible to secure the wireless band while the contracted capacity of each wireless communication terminal is used as it is. Further, since the wireless communication terminals to be used can be those of different wireless line carriers or different wireless communication protocols, the risk at the time of failure can be reduced.

The second effect is that by using a plurality of wireless communication terminals to bundle the wireless lines, it is possible to realize securing of a wireless band equal to or more than one wireless line without being aware of it.

The third effect is that it is possible to support the NAT traversal of IPsec and the new protocol of IPv6, which are increasingly used in the IPv4 protocol in recent years. In the future, it is expected that the infrastructure using IPv6 addresses with a large number of bits of host addresses will increase due to the spread of IOT (Internet Of Things), etc. It is possible to use as it is without performing.

(Other embodiment of this embodiment)
In the above-described embodiment, as shown in FIGS. 1 and 2, the main line using the main wireless communication terminal 5 has been described on the assumption that the IPv4 protocol is used. It is not limited to such a case. For example, the IPv6 protocol may be used for the main line using the main wireless communication terminal 5. FIG. 10 is a connection configuration diagram showing an example of the connection configuration of the media adapter device according to the present invention, which is different from FIGS. 1 and 2, and shows the case where the IPv6 protocol is used in the main line.

Note that, in FIG. 10, there is a difference from the configuration example shown in FIG. 2 of the above-described embodiment in that the IPv6 protocol is used for the main line passing through the main wireless communication terminal 5, and the respective devices are different from each other. Even though the exchanged communication contents are different in form, the substantial communication contents are substantially the same, so the three-digit code 100s in FIG. It has been changed from "3" to "4".

In FIG. 10, when an RS (Router Solicitation) 401 of IPv6 protocol is transmitted from the router device 1 connected to the LAN side of the media adapter device 3, the media adapter device 3 causes the interface 4 for the main line to By transmitting the IPv6 address proxy connection request 404 from the connected main wireless communication terminal 5, the wireless network operator network 7 is accessed and the IPv6 address 403 is acquired from the Internet network 8. Then, the media adapter device 3 extracts the prefix (Prefix) of the acquired IPv6 address and returns it to the router device 1 as RA (Router Advertisement) 400 which is a response to the RS 401.

The router device 1 generates the IPv6 address by receiving the prefix of the IPv6 address as the RA 400. When the IPsec communication of the IPv6 address generated by the router device 1 is received, the media adapter device 3 performs NAT conversion into the IPv6 address previously acquired via the main line interface 4 to communicate with the Internet network 8. You will be able to.

The media adapter device 3 also accesses the wireless network operator network 7 from the band securing wireless communication terminal 12 to acquire address information. Further, when the media adapter device 3 starts the IPsec communication 405 as the IPsec communication connection process from the router device 1, the media adapter device 3 establishes the SA when performing the VPN connection with the opposite center router device 10. That is, the SA is established by performing NAT conversion to the IPv6 address previously received from the main wireless communication terminal 5 and communicating with the opposite center router device 10 via the Internet 8.

At the same time, the media adapter device 3 exchanges information regarding the bandwidth securing interface 11 with the opposite center router device 10 by TCP communication 414 with the management communication port number “500”, and the center router device 10 exchanges the information. 10 is notified of the IP address (IPv4 address/IPv6 address). Further, the media adapter device 3 acquires the designated TCP port number and the peer address in the case of IPv4 from the opposite center router device 10. When the media adapter device 3 acquires the TCP port number and the peer address as the information regarding the band securing interface 11, the media adapter device 3 performs the TCP communication of the designated TCP port number from the band securing interface 11 to communicate with the center router device 10. TCP communication 413 can be performed.

If the contract for the band securing wireless communication terminal 12 is the terminal of the IPv4 protocol, the media adapter device 3 acquires the IPv4 in the IPsec management communication of the TCP communication 414 and registers it in the management parameter 17. It is possible to maintain the TCP connection of the band securing wireless communication terminal 12 by reading out the peer address of No. 1, and performing TCP communication to the peer address. Note that the media adapter device 3 registers the communication management information acquired at the start of TCP communication in the management parameter 17, but when the registered information is changed, the changed information is updated to the management parameter 17. While registering, the information is transmitted to the center router device 10 by TCP communication with the port number “500” using the main line interface 4 to confirm the information.

When the media adapter device 3 receives the ESP packet by the IPsec communication 416 from the router device 1 after the registration information of the management parameter 17 is confirmed with the center router device 10, the ESP packet is received. Is distributed as an IPsec data packet through the main wireless communication terminal 5 and the band securing wireless communication terminal 12, and the operation of sequentially transferring by the round robin method is started. In other words, when the media adapter device 3 passes through the main wireless communication terminal 5, it transmits the IPsec data packet as it is to the center router device 10 by the IPsec communication 412 according to the IPv6 protocol. When passing through, the IPsec data packet is TCP-encapsulated and then transmitted to the center router device 10 by TCP communication 413.

As described above, in the connection configuration shown in FIG. 10, when the contract of the main wireless communication terminal 5 is the IPv6 protocol, the router device 1 receives the prefix (Prefix) of the IPv6 address acquired by transmitting the RS 401. Upon receiving the data using the IPv6 address generated based on the above, the media adapter device 3 can access the Internet network 8 by performing NAT conversion to the IPv6 address acquired via the main wireless communication terminal 5. it can. Therefore, the router device 1 can communicate with the Internet network 8 by acquiring the prefix (Prefix) of the IPoE (Internet Protocol over Ethernet) method, and also in the IPsec communication, the peer address of the IPv6 address as the destination can be set. It can be implemented by setting.

The configuration of the preferred embodiment of the present invention has been described above. However, it should be noted that such an embodiment is merely an example of the present invention and does not limit the present invention in any way. Those skilled in the art can easily understand that various modifications and changes can be made according to a specific application without departing from the gist of the present invention.

1 router device 2 LAN cable 3 media adapter device 4 main line interface 5 main wireless communication terminal 6 main wireless line 7 wireless line carrier network 8 internet network 10 center router device 11 band securing interface 12 band securing wireless communication terminal 13 Bandwidth securing wireless line 16 Management parameter 17 Management parameter 18 Router setting parameter 200 First line (bandwidth securing protocol header)
201 port number 202 Bandwidth reservation hostname
203a 3rd line (bandwidth securing protocol header)
203b Line 4 (bandwidth securing protocol header)
203c 5th line (bandwidth securing protocol header)
203d line 6 (bandwidth securing protocol header)
205 1st line (protocol header for IPsec management communication)
206 port number 207 bandwidth reservation hostname
208a Third line (IPsec management communication protocol header)
208b Fourth line (IPsec management communication protocol header)
208c line 9 (protocol header for IPsec management communication)
208d line 10 (protocol header for IPsec management communication)
209 4th line from 5th line to 8th line (protocol header for IPsec management communication)
210 line 11 (protocol header for IPsec management communication)
300 Response 301 Connection Request 302 IPsec Communication 303 IP Address 304 Proxy Connection Request 305 IPsec Communication 306 Proxy Connection Request 307 IP Address 312 IPsec Communication 313 TCP Communication (Encapsulated IPsec Communication)
314 TCP communication 316 IPsec communication 400 RA
401 RS
403 IPv6 address 404 IPv6 address Proxy connection request 405 IPsec communication 412 IPsec communication 413 TCP communication 414 TCP communication 416 IPsec communication

Claims (10)

In a network system for connecting a router device connected to a LAN (Local Area Network) to a center router device connected to an internet network via a wireless line, for connecting the router device to the internet network via a wireless line Is a media adapter device for performing media conversion of
As an interface on the WAN (Wide Area Network) side,
A main line interface for connecting a main wireless communication terminal for transmitting and receiving radio signals relating to data flowing on the main wireless line,
One or a plurality of band securing interfaces for respectively connecting one or a plurality of band securing wireless communication terminals for securing a wireless line for securing a wireless band;
Equipped with
When a data packet addressed to the center router device is received from the router device, the data packet is subjected to media conversion, and a round robin method is used for the main line interface and one or more band securing interfaces. To the Internet network via the main wireless communication terminal and one or more of the band securing wireless communication terminals, and distributes to the destination center router device.
A media adapter device characterized by the above. Communication management information relating to communication through each of the one or a plurality of bandwidth securing interfaces is transmitted to the opposite side center router device via the main line interface and managed in the center router device. Equipped with means to register as parameters,
A data packet addressed to the router device is referred from the center router device to the main wireless communication terminal and one or more band securing wireless communication terminals by a round robin method with reference to the management parameter. When the transmission is detected in order,
The router device as the destination by associating the data packet transmitted via each of the one or a plurality of band securing wireless communication terminals with the data packet transmitted via the main wireless communication terminal. To deliver to,
The media adapter device according to claim 1, wherein: The data packet transmitted/received between the router device and the center router device is an IPsec data packet complying with an IPsec (Security Architecture for Internet Protocol) protocol,
When the data is transmitted and received through the main line interface, the IPsec data packet is transmitted and received as the IPsec communication,
When transmitted/received via the band securing interface, the IPsec data packet is TCP-encapsulated and transmitted/received as TCP communication.
The media adapter device according to claim 1, wherein the media adapter device is a media adapter device. In order to maintain a communication route through the bandwidth securing interface, a keep-alive between the center router device and each of the one or more bandwidth securing interfaces is periodically performed at a predetermined time interval. Send alive,
The media adapter device according to any one of claims 1 to 3, wherein In a network system for connecting a router device connected to a LAN (Local Area Network) to a center router device connected to an internet network via a wireless line, for connecting the router device to the internet network via a wireless line Is a distributed communication management method in a media adapter device for performing media conversion of
The media adapter device is
A main line interface for connecting a main wireless communication terminal for transmitting and receiving a wireless signal relating to data flowing on a main wireless line, and one or a plurality of band securing wireless communication terminals for securing a wireless band for securing a wireless band. A step of transmitting and receiving data via each of one or a plurality of bandwidth securing interfaces connecting the respective,
Have
When a data packet addressed to the center router device is received from the router device, the data packet is subjected to media conversion, and a round robin method is used for the main line interface and one or more band securing interfaces. To the Internet network via the main wireless communication terminal and one or more of the band securing wireless communication terminals, and distributes to the destination center router device.
A distributed communication management method characterized by the above. The media adapter device is
Communication management information relating to communication through each of the one or a plurality of bandwidth securing interfaces is transmitted to the opposite side center router device via the main line interface and managed in the center router device. Has a step of registering as a parameter,
A data packet addressed to the router device is referred from the center router device to the main wireless communication terminal and one or more band securing wireless communication terminals by a round robin method with reference to the management parameter. When it is detected that the data has been sent in order,
The router device as the destination by associating the data packet transmitted via each of the one or a plurality of band securing wireless communication terminals with the data packet transmitted via the main wireless communication terminal. To deliver to,
The distributed communication management method according to claim 5, wherein The data packet transmitted/received between the router device and the center router device is an IPsec data packet complying with an IPsec (Security Architecture for Internet Protocol) protocol,
When the data is transmitted and received through the main line interface, the IPsec data packet is transmitted and received as the IPsec communication,
When transmitted/received via the band securing interface, the IPsec data packet is TCP-encapsulated and transmitted/received as TCP communication.
The distributed communication management method according to claim 5 or 6, characterized in that. In order to maintain a communication route through the bandwidth securing interface, a keep-alive between the center router device and each of the one or more bandwidth securing interfaces is periodically performed at a predetermined time interval. Send alive,
The distributed communication management method according to any one of claims 5 to 7, characterized in that. In a network system for connecting a router device connected to a LAN (Local Area Network) to a center router device connected to an internet network via a wireless line, for connecting the router device to the internet network via a wireless line Is a distributed communication management program executed by a computer in a media adapter device for performing media conversion of
The media adapter device is
A main line interface for connecting a main wireless communication terminal for transmitting and receiving a wireless signal relating to data flowing on a main wireless line, and one or a plurality of band securing wireless communication terminals for securing a wireless band for securing a wireless band. A function for transmitting and receiving data via each of one or a plurality of bandwidth securing interfaces that connect the respective
Have
When a data packet addressed to the center router device is received from the router device, the data packet is subjected to media conversion, and a round robin method is used for the main line interface and one or more band securing interfaces. To the Internet network via the main wireless communication terminal and one or more of the band securing wireless communication terminals, and distributes to the destination center router device.
A distributed communication management program characterized by the above. The media adapter device is
Communication management information relating to communication through each of the one or a plurality of bandwidth securing interfaces is transmitted to the opposite side center router device via the main line interface and managed in the center router device. It has a function to register as a parameter,
A data packet addressed to the router device is referred from the center router device to the main wireless communication terminal and one or more band securing wireless communication terminals by a round robin method with reference to the management parameter. When it detects that they have been sent in order and sent in order,
The router device as the destination by associating the data packet transmitted via each of the one or a plurality of band securing wireless communication terminals with the data packet transmitted via the main wireless communication terminal. To deliver to,
The distributed communication management program according to claim 9, wherein

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