JP2014236433A - Communication apparatus, transmission control method and transmission control program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication apparatus capable of selecting a network available for communication on each flow even when the connection between a packet transfer section and a transmission control section is disconnected.SOLUTION: The communication apparatus which uses a network control system of a flow unit includes: one or more communication interfaces; a communication stack which has one or more channel tables; a packet transfer section that transfers a received packet; a transmission control section that controls the operation of a packet transfer section. When the connection between the packet transfer section and the transmission control section is disconnected and when the packet transfer through the packet transfer section and the transmission control section gets impossible, the communication apparatus switches the channel table which is used for controlling the channel by the communication stack.

Description

  The present invention relates to a communication apparatus that performs IP communication on a network, a transfer control method, and a transfer control program, and in particular, uses a network control method in units of flows that can select a network to be used for communication for each flow. The present invention relates to a communication device, a transfer control method applied to the communication device, and a transfer control program.

  In recent years, high-performance communication devices such as smartphones and tablets have been rapidly spreading. Since these communication devices have a large amount of traffic for transmission and reception compared to conventional communication devices, the increase in network load has become serious, and efficient use of the network is one of the problems in communication devices.

  High-speed wireless communication technologies such as wireless LAN (Wireless Local Area Network), 3G (3rd generation mobile communication system), WiMAX (Worldwide Interoperability for Microwave Access), LTE (Long Term Evolution), etc. It has become common to have a plurality of communication interfaces. The communication device includes a plurality of communication interfaces, thereby enabling communication using a plurality of networks. In addition, on these communication apparatuses, various communication programs having different communication characteristics such as a protocol used for communication, a communication frequency, and a traffic amount of transmission / reception are operated.

  Therefore, by performing communication using an appropriate network for each communication program based on the characteristics of a network connected via a plurality of communication interfaces and the communication characteristics of a communication program operating on a communication device, the network It can be expected to ease the load.

  Various proposals have been made for performing communication using an appropriate network in a communication apparatus that includes a plurality of communication interfaces and can perform communication using a plurality of networks. For example, the method described in Patent Document 1 preferentially sets any one of a plurality of communication interfaces included in a communication device based on the network configuration, communication quality, battery charge, charge amount, and the like. As the route information related to the default gateway, only the route information related to the default gateway set to the communication interface set predominantly among the default gateways set for each of the plurality of communication interfaces is set in the route table.

  In IP communication, when communicating with a communication device on a network other than the network to which the communication device is directly connected, communication is performed via the default gateway by route control based on the route information about the default gateway set in the route table. Therefore, communication is performed using a network that is connected via a communication interface that is set to be superior.

International Publication No. 2009/057477

  Although the method described in Patent Document 1 enables communication using an appropriate network connected through a plurality of communication interfaces, the default set in the preferentially set communication interface Since only route information related to the gateway is set in the route table, communication with a communication device on a network other than the network to which the communication device directly connects using a network other than the network connected via the preferentially set communication interface There is a problem that cannot be performed.

  The network used for communication by the communication program is determined in the route control based on the IP address of the communication device that is the transmission destination of the communication program and the route information set in the route table. There is also a problem that it is not possible to arbitrarily select the communication method, which is insufficient as a method for performing communication using an appropriate network for each communication program.

  Therefore, it is possible to communicate with a communication device on a network other than the network to which the communication device is directly connected in any of the networks connected via the plurality of communication interfaces provided in the communication device. In addition, a method capable of selecting a network to be used for communication by specifying a communication interface or default gateway used for communication at a finer granularity such as for each communication program is desired.

  The present invention has been made in view of the above-described problems related to a communication apparatus that includes a plurality of communication interfaces and can perform communication using a plurality of networks. The communication apparatus includes a plurality of communication interfaces. Communication with a communication device on a network other than the network to which the communication device is directly connected, and communication used by the user or any program for each flow. It is an object of the present invention to provide a communication device, a transfer control method, and a transfer control program that can select a network to be used for communication for each flow by specifying an interface.

  A communication apparatus according to the present invention is a communication apparatus that uses a network control method in units of flows and that can select a network to be used for communication for each flow, and includes a plurality of communication interfaces and a packet transfer unit that transfers received packets. And a transfer control unit for controlling the operation of the packet transfer unit. With this configuration, communication can be performed using an appropriate network for each flow.

  In addition, the transfer control method according to the present invention includes a plurality of communication interfaces and a packet transfer unit that transfers received packets, and a network that is used for communication for each flow in a communication device that uses a network control method in units of flows. A packet transfer rule generation step for generating a packet transfer rule that is information for determining the operation of the packet transfer unit, and the packet transfer rule generated by the packet transfer rule generation step And a packet transfer unit management step set in the packet transfer unit. With this configuration, the communication apparatus can perform packet transfer for performing communication using an appropriate network for each flow.

  In addition, a transfer control program according to the present invention includes a plurality of communication interfaces and a packet transfer unit that transfers received packets. A computer that uses a network control method in units of flows is provided with a network that is used for communication for each flow. A program for executing a process for enabling selection, wherein the program causes the computer to generate a packet transfer rule that generates packet transfer rule that is information for determining an operation of the packet transfer unit, and to generate the packet transfer rule. And a packet transfer unit management process for setting the packet transfer rule generated by the process in the packet transfer unit. With this configuration, the computer can perform packet transfer for performing communication using an appropriate network for each flow.

  Further, the communication device according to the present invention is a communication device that uses a network control method in units of flows, capable of selecting a network to be used for communication for each flow, and includes a plurality of communication interfaces, a virtual interface, A communication stack having a plurality of routing tables, a packet transfer unit for transferring received packets, a transfer control unit for controlling the operation of the packet transfer unit, and a connection between the packet transfer unit and the transfer control unit are monitored. A connection monitoring unit. With this configuration, when the connection between the packet transfer unit and the transfer control unit is disconnected, it is possible to detect that and take necessary measures.

  The plurality of route tables include a first route table used for enabling communication by packet transfer by the packet transfer unit and the transfer control unit, and a second route used when the packet transfer cannot be performed. And a table. With this configuration, when the connection between the packet transfer unit and the transfer control unit is disconnected, the communication device on the network other than the network to which the communication device is directly connected and the plurality of communication interfaces are connected depending on the first route table. Even if communication with a communication device on the network connected through the communication stack becomes impossible, switching to the second route table can be avoided by causing the route table used for route control of the communication stack to be incapable of communication. .

  The transfer control unit is an address storage for storing address information set for the plurality of communication interfaces and the virtual interface, which is information necessary for the plurality of communication interfaces and the virtual interface to transmit and receive packets. An address information management unit that acquires the address information and stores it in the address storage unit, and a routing table management unit that sets the first routing table based on the information stored in the address information management unit The route table management unit may set the first route table with route information related to a virtual default gateway set in the virtual interface. With this configuration, when the packet transfer unit and the transfer control unit are connected, the communication stack performs route control using the first route table, so that the packet transfer unit and the transfer control are performed. It is possible to perform communication using an appropriate network for each flow by packet transfer by the unit.

  The communication stack is based on an address storage unit that stores the address information, an address information management unit that acquires the address information and stores the address information in the address storage unit, and information stored in the address information management unit, A routing table management unit configured to set a second routing table, wherein the routing table management unit includes routing information related to any one of the default gateways set for each of the plurality of communication interfaces. May be set in the second routing table. With this configuration, even when the connection between the packet transfer unit and the transfer control unit is disconnected, the communication stack can perform communication by performing route control using the second route table. Become.

  The connection monitoring unit switches a route table used for route control of the communication stack to the first route table or the second route table based on a connection state between the packet transfer unit and the transfer control unit. It's okay. Even if the packet transfer unit and the transfer control unit are connected by switching the routing table used for route control of the communication stack by the connection monitoring unit, the communication can be performed. It becomes possible to do.

  The transfer control method according to the present invention controls a plurality of communication interfaces, a virtual interface, a communication stack having a plurality of routing tables, a packet transfer unit for transferring received packets, and an operation of the packet transfer unit. A communication device using a network control method in units of flows, wherein the connection between the packet transfer unit and the transfer control unit is monitored. A transfer control method for performing communication by switching a route table used for route control of the communication stack based on a connection state between the packet transfer unit and the transfer control unit have. With this configuration, when the connection between the packet transfer unit and the transfer control unit is disconnected, communication can be performed by detecting this and switching the route table used for route control of the communication stack.

  The transfer control program according to the present invention controls a plurality of communication interfaces, a virtual interface, a communication stack having a plurality of routing tables, a packet transfer unit for transferring received packets, and an operation of the packet transfer unit. A computer that uses a network control method for each flow, and that monitors a connection between the packet transfer unit and the transfer control unit. A program that performs communication by switching a route table used for route control of the communication stack based on a connection state between the packet transfer unit and the transfer control unit. doing. With this configuration, when the connection between the packet transfer unit and the transfer control unit is disconnected, communication can be performed by detecting this and switching the route table used for route control of the communication stack.

  According to the present invention, communication with a communication device on a network other than the network to which the communication device is directly connected is performed when any of the networks connected via the plurality of communication interfaces provided in the communication device is used. Further, by making it possible to select a network to be used for communication for each flow, there is an effect that communication can be performed using an appropriate network for each flow.

The block diagram which shows the structural example of the communication apparatus in embodiment of this invention. The block diagram which shows the structural example of the packet transfer part in embodiment of this invention The flowchart which shows the example of a process when a packet transfer part receives a packet The block diagram which shows the structural example of the more detailed communication apparatus which paid its attention to the element which concerns on 1st Embodiment. The block diagram which shows the structural example of the transfer control part in embodiment of this invention Configuration example of routing table in the first embodiment The flowchart which shows the example of the process which the transfer control part in 1st Embodiment produces | generates a packet transfer rule The block diagram which shows the structural example of the more detailed communication apparatus which paid its attention to the element which concerns on 2nd Embodiment. Configuration example of routing table in the second embodiment The flowchart which shows the example of the process which the transfer control part in 2nd Embodiment produces | generates a packet transfer rule The flowchart which shows the example of the address resolution process of the transfer control part in 2nd Embodiment Configuration example of use interface information stored in use interface information storage unit in third embodiment The block diagram which shows the structural example of the more detailed communication apparatus which paid its attention to the element which concerns on 4th Embodiment. A block diagram showing an example of composition of a communication stack in a 4th embodiment Configuration example of routing table in the fourth embodiment The block diagram which shows the structural example of the more detailed communication apparatus which paid its attention to the element which concerns on communication when the packet transfer in 4th Embodiment cannot be performed

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is a block diagram illustrating a configuration example of a communication device according to an embodiment of the present invention. A communication apparatus 100 according to an embodiment of the present invention is a communication apparatus that uses a network control method in units of flows, and includes a plurality of communication interfaces 101, a packet transfer unit 200 that transfers received packets, and a packet transfer unit. And a transfer control unit 300 that controls the operation.

  A flow refers to a flow of a series of packets of traffic that can be identified by a combination of arbitrary addresses and identifiers. By using a flow-by-flow network control method, it is possible to realize finer and more flexible network control. The network control method for each flow is, for example, OpenFlow. An example of an OpenFlow communication device that includes a flow switch that forwards received packets and a flow controller that controls the operation of the flow switch is “Nick McKeown, 7 others,“ OpenFlow: Enabling Innovation in Campus Networks ”, 2008. March 14, Internet <http://www.openflow.org/documents/openflow-wp-latest.pdf> "or" "OpenFlow Specification Version 1.0.0", December 31, 2009 , Internet <http://www.openflow.org/documents/openflow-spec- It is described in the 1.0.0.pdf> ", and the like.

  The packet transfer unit 200 is, for example, a flow switch in OpenFlow. The transfer control unit 300 is a flow controller in OpenFlow, for example.

  The packet transfer unit 200 transfers the received packet. Specifically, the packet transfer unit 200 performs arbitrary processing on the received packet based on the packet transfer rule. The packet transfer rule is information that determines the operation of the packet transfer unit 200 when a packet is received, and is set by the transfer control unit 300.

  The packet transfer rule includes flow information that is information that can identify a flow, and action information that is information that determines the content of a process to be executed on a packet of a flow that matches the flow information. The packet transfer rule includes at least flow information and action information, but may further include other information.

  The flow information includes, for example, a transmission source MAC address, a transmission destination MAC address, an Ethernet (registered trademark) frame type, a transmission source IP address, a transmission destination IP address, a transmission source port number, a transmission destination port number, and a packet from which communication interface. The reception port number or the like which is information for determining whether the information has been received is included, but the flow information is not limited to these, and may further include other information. The contents of the action information include, for example, transmitting a packet to an arbitrary communication interface, transmitting the packet to the communication stack, rewriting an arbitrary address or identifier included in the packet to an arbitrary value, or discarding the packet. However, the content of the action information is not limited to these.

  The communication interface refers to an interface that provides a function of enabling communication by connecting to an arbitrary network. In the embodiment of the present invention, the type of communication interface is not particularly limited, and may be a wired interface such as Ethernet (registered trademark), a wireless interface such as a wireless LAN, or a virtual interface generated by an arbitrary method. Examples of virtual interfaces include a tunnel interface and a logical interface generated by link aggregation, which is a method of virtually bundling a plurality of communication interfaces. Further, the number of communication interfaces is not particularly limited, and may be one or more. Furthermore, the plurality of communication interfaces 101 may all be the same type of communication interface, or different types of communication interfaces may be mixed.

  Note that the plurality of communication interfaces 101 included in the communication device 100 according to the embodiment of the present invention includes one or more and any type of communication interfaces. For convenience, in the embodiment of the present invention, it is assumed that the networks connected via the plurality of communication interfaces 101 are different networks, but one or more communication interfaces among the plurality of communication interfaces 101 are the same. It may be configured to connect to other networks.

  FIG. 2 is a block diagram illustrating a configuration example of the packet transfer unit according to the embodiment of the present invention. The packet transfer unit 200 includes a packet transfer rule storage unit 201, a packet transfer rule management unit 202, a flow identification unit 203, and an action execution unit 204.

  The plurality of communication interfaces 101 in the embodiment of the present invention are connected to the packet transfer unit 200. Specifically, each communication interface of the plurality of communication interfaces 101 is registered in the packet transfer unit 200 as a port of the packet transfer unit 200. With this configuration, the packet transfer unit 200 can perform packet transfer via each communication interface of the plurality of communication interfaces 101.

  The packet transfer rule storage unit 201 stores packet transfer rules. Since different packet transfer rules are set for each flow, the packet transfer rule storage unit 201 stores one or more packet transfer rules. A set of packet transfer rules stored in the packet transfer rule storage unit 201 is referred to as a packet transfer rule table.

  The packet transfer rule management unit 202 manages packet transfer rules. When setting a packet transfer rule in the packet transfer unit 200, the transfer control unit 300 transmits a setting instruction together with the packet transfer rule. Specifically, the setting instruction is information that determines whether to add, change, or delete a packet transfer rule. The packet transfer rule management unit 202 stores the packet transfer rule received from the transfer control unit 300 in the packet transfer rule storage unit 201 according to the setting instruction.

  In addition to flow information and action information, the packet transfer rule includes a timer value that is information for determining the validity period of the packet transfer rule. The packet transfer rule management unit 202 decreases the timer value specified in each packet transfer rule with the passage of time. Then, the packet transfer rule whose timer value is 0 is deleted from the packet transfer rule storage unit 201. When a packet of a flow that conforms to the flow information included in the packet transfer rule is received, the packet transfer rule management unit 202 resets the timer value of the packet transfer rule to an initial value.

  When the flow identification unit 203 receives a packet, the flow identification unit 203 generates flow information from an arbitrary address or identifier included in the received packet. Based on the generated flow information, a search is made as to whether or not a packet transfer rule including flow information matching the flow of the received packet exists on the packet transfer rule table stored in the packet transfer rule storage unit 201.

  The action execution unit 204 executes arbitrary processing on the received packet based on the content of the action information included in the packet transfer rule.

  Next, the operation of the packet transfer unit 200 will be described. FIG. 3 is a flowchart illustrating an example of processing when the packet transfer unit receives a packet. When the packet transfer unit 200 receives a packet from any one of the plurality of communication interfaces 101 (step S101), the flow identification unit 203 generates flow information from the received packet (step S102). Based on the received flow information, it is determined whether or not a packet transfer rule including flow information matching the flow of the received packet exists on the packet transfer rule table stored in the packet transfer rule storage unit 201 (step S103). ).

  When there is no packet transfer rule including flow information that matches the flow of the received packet (No in step S103), the flow identification unit 203 controls transfer of a new flow detection notification including the flow information generated by the flow identification unit 203. The request is transmitted to the unit 300 (step S104), and a packet transfer rule is generated for the received packet flow. The flow identification unit 203 may include the received packet itself in the new flow detection notification. When receiving the new flow detection notification, the transfer control unit 300 generates a packet transfer rule and transmits it to the packet transfer unit 200 together with a setting instruction.

  When the packet transfer rule management unit 202 receives the packet transfer rule and the setting instruction transmitted from the transfer control unit 300, the packet transfer rule management unit 202 stores the packet transfer rule received according to the instruction in the packet transfer rule storage unit 201 (step S105). .

  If there is a packet transfer rule that includes flow information that matches the flow of the received packet (Yes in step S103), the packet transfer rule management unit 202 sets the packet transfer rule that includes flow information that matches the flow of the received packet. The timer value is reset to the initial value (step S106).

  By performing the processing as described above, a packet transfer rule that matches the flow of the received packet can be obtained. The action execution unit 204 executes arbitrary processing on the received packet based on the action information included in the packet transfer rule that matches the flow of the received packet (step S107).

  FIG. 4 is a block diagram illustrating a more detailed configuration example of the communication apparatus focusing on elements related to communication in the first embodiment. The communication device 100 according to the first embodiment includes a plurality of communication interfaces 101 and a virtual interface 102. The plurality of communication interfaces 101 and the virtual interface 102 are connected to the communication stack 103 and the packet transfer unit 200 of the communication device 100. The virtual interface 102 is a communication interface that is not connected to any of the networks that are connected via the plurality of communication interfaces 101. In other words, the virtual interface 102 is a communication interface for connecting to a virtual network existing inside the communication device 100.

  The plurality of communication interfaces 101 and the virtual interface 102 in the embodiment of the present invention are connected to the communication stack 103. Specifically, path information for transmitting a packet to each communication interface of the plurality of communication interfaces 101 and a communication apparatus on the network connected via the virtual interface 102, that is, an output interface is each communication interface. The route information is set on the route table. Based on the route table in which such route information is set, a packet can be transmitted through each communication interface by route control performed by the communication stack 103.

  With the configuration as shown in FIG. 4, the packet transfer unit 200 transmits a packet transmitted from the communication program 105 operating on the communication device 100 or another communication device among the plurality of communication interfaces 101 and virtual interfaces 102. Can be received from any communication interface.

  Note that the communication program 105 operating on the communication device 100 in the embodiment of the present invention refers to any program that performs IP communication. The type of communication program, the protocol used for communication, the content of communication, etc. are not particularly limited. Moreover, the number is not specifically limited, One or more communication programs may operate | move.

  The packet transfer unit 200 and the transfer control unit 300 are connected by an arbitrary method. For example, the connection is made by UNIX (registered trademark) domain socket communication, TCP (Transmission Control Protocol) communication, or SSL (Secure Socket Layer) communication.

  As shown in FIG. 5, the transfer control unit 300 includes a use interface information storage unit 301, a use interface information management unit 302, an address information storage unit 303, an address information management unit 304, a route table management unit 305, A packet transfer rule generation unit 306 and a packet transfer unit management unit 307 are provided.

  The used interface information is information that determines which communication interface among the plurality of communication interfaces 101 is used for communication for each flow, and is flow information that can identify a flow, and a plurality of communication interfaces. 101, information that can uniquely identify any one of 101. The used interface information includes at least flow information and information that can uniquely identify any one of the plurality of communication interfaces 101, but may include other information.

  The flow information included in the used interface information may include a wild card in the value of the information included therein. Information that can uniquely identify any of the plurality of communication interfaces 101 is, for example, an interface name, a port number, or the like.

  The used interface information storage unit 301 stores used interface information. Since different used interface information is set for each flow, the used interface information storage unit 301 stores one or more used interface information.

  The used interface information management unit 302 manages the used interface information and provides a function for allowing the user or an arbitrary program to set the used interface information at an arbitrary timing. When setting the use interface information in the use interface information management unit 302, the user or an arbitrary program gives a setting instruction together with the use interface information. Specifically, the setting instruction is information that determines whether to add, change, or delete the used interface information. The used interface information management unit 302 stores the used interface information given from the user or an arbitrary program in the used interface information 301 according to the setting instruction.

  The use interface information management unit 302 can set the use interface information provided to the user or an arbitrary program, for example, a graphical user interface for performing the setting, an arbitrary API that can be used from an arbitrary program ( Application Programming Interface).

  The address information storage unit 303 stores address information that is information necessary for the plurality of communication interfaces 101 and the virtual interface 102 to transmit and receive packets. Since the address information is set for each communication interface, the address information storage unit 303 stores one or more pieces of address information.

  The address information includes, for example, a MAC address, an IP address, a subnet mask, a MAC address and an IP address of a default gateway on the network connected via the communication interface, and a packet transfer for identifying a communication interface connected to the packet transfer unit 200 The port information assigned by the unit 200 is included, but the address information is not limited to these, and may include other information. The address information is set for each communication interface by an arbitrary method. An arbitrary method for setting the address information is, for example, fixed setting by a user or an arbitrary program, DHCP (Dynamic Host Configuration Protocol), IPCP (Internet Protocol Control Protocol), or the like.

  Address information is set in the virtual interface 102 in the same manner as each communication interface of the plurality of communication interfaces 101, but the address information is virtual address information composed of arbitrary values. Specifically, the address information of the virtual interface 102 includes at least a virtual MAC address, a virtual IP address, and a virtual default gateway that is a default gateway on the virtual network inside the communication apparatus 100 connected via the virtual interface 102. MAC address and IP address.

  The address information management unit 304 acquires address information set for each communication interface of the plurality of communication interfaces 101 and the virtual interface 102 and stores the acquired address information in the address information storage unit 303. Further, the address information management unit 304 re-addresses the address information of the communication interface in which the change of the address information occurs when the change of the address information occurs due to the DHCP lease expiration or the occurrence of a handover accompanying the movement of the communication device. Acquired and stored in the address information storage unit 303.

  The routing table management unit 305 includes a default gateway set for each communication interface of the plurality of communication interfaces 101 included in the address information stored in the address information storage unit 305, and a virtual default gateway set for the virtual interface 102. Only the route information related to the virtual default gateway is set in the route table 104 of the communication stack 103.

  FIG. 6 is a configuration example of a route table according to the first embodiment. The route table 104 is set by the route table management unit 305 as shown in FIG. As the route information related to the route to each network connected via the plurality of communication interfaces 101, the route information that the destination network is each network connected via the plurality of communication interfaces 101 and the output interface is each communication interface is provided. Is set. Further, as route information regarding a route to a virtual network connected via the virtual interface 102, route information in which the destination network is a virtual network and the output interface is a virtual interface is set. As the route information related to the default gateway, only the route information that is the virtual default gateway in which the next hop is set to the virtual interface is set.

  The route information related to the default gateway set in the route table 104 is not only the route information related to the virtual default gateway set in the virtual interface 102 but also the route related to the default gateway set for each communication interface of the plurality of communication interfaces 101. Information may be set. However, if there is route information related to multiple default gateways on the route table, it is not possible to know which route information should be used for route control, and communication will be impossible. Therefore, the path information related to the virtual default gateway is selected from the default gateway set for each communication interface of the plurality of communication interfaces 101 and the virtual default gateway set for the virtual interface. Set to advantage.

  By setting only the route information related to the virtual default gateway among the default gateway set to each communication interface of the plurality of communication interfaces 101 and the virtual default gateway set to the virtual interface 102, the communication program 105 However, when the communication apparatus 100 performs communication with a communication apparatus on a network other than the network directly connected via the plurality of communication interfaces 101, the packet transmitted from the communication program 105 is controlled by the path control performed by the communication stack 103. Will be sent to the virtual default gateway. Specifically, after the path control is performed in the communication stack 103, when the packet transfer unit 200 receives the packet transmitted from the communication program 105 from the virtual interface 102, the source MAC address of the packet is the virtual interface. The virtual MAC address set to 102, the destination MAC address of the packet becomes the MAC address of the virtual default gateway, the source IP address of the packet becomes the virtual IP address set to the virtual interface 102, and the packet The destination IP address is the IP address of the destination communication device.

  On the other hand, when the communication program 105 communicates with a communication device on a network connected via a plurality of communication interfaces 101, the packet transmitted from the communication program 105 is transmitted to the destination by the path control performed by the communication stack 103. It is transmitted directly to the destination communication device via the communication interface connected to the network in which the communication device exists. Specifically, after route control is performed in the communication stack 103, the packet transfer unit 200 receives a packet transmitted from the communication program 105 from a communication interface connected to a network in which a destination communication device exists. The source MAC address of the packet is the MAC address set for the communication interface, the destination MAC address of the packet is the MAC address of the destination communication device, and the source IP address of the packet is the communication The IP address is set to the interface, and the destination IP address of the packet is the IP address of the destination communication device.

  The packet transfer rule generation unit 306 receives a new flow detection notification transmitted from the flow identification unit 203 of the packet transfer unit 200, that is, when a request for generation of a packet transfer rule is received from the packet transfer unit 200. A packet transfer rule is generated based on the flow information included in the detection notification, the used interface information stored in the packet transfer rule storage unit 301, and the address information stored in the address information storage unit 303.

  Next, a packet transfer rule generation method in the packet transfer rule generation unit 306 will be described. FIG. 7 is a flowchart illustrating an example of processing in which the transfer control unit according to the first embodiment generates a packet transfer rule.

  When the packet transfer rule generation unit 306 receives the new flow detection notification, the packet transfer rule generation unit 306 refers to the flow information included in the new flow detection notification and identifies the communication interface that has received the packet based on the reception port number included in the flow information. . Then, the address information of the communication interface that received the packet and the address information of the virtual interface 102 are acquired through the address information management unit 304 (step S201). Note that the communication interface that has received the packet specified by the reception port number included in the flow information is one of the plurality of communication interfaces 101 and the virtual interface 102.

  Next, the packet transfer rule generation unit 306 refers to the flow information included in the new flow detection notification and identifies the source IP address of the received packet. Then, based on the subnet mask included in the address information of the communication interface that received the packet, the network address obtained from the identified source IP address, the network address obtained from the IP address set in the communication interface that received the packet, Are equal to each other (step S202). That is, based on the source IP address of the received packet, it is determined whether or not the packet is a packet transmitted from a communication device on the network connected via the communication interface that received the packet.

  If the network address obtained from the identified source IP address and the network address obtained from the IP address set in the communication interface that received the packet are not equal (No in step S202), the communication address is received via the communication interface that received the packet. It can be determined that the packet is transmitted from a communication device on a network other than the network to which the communication device 100 is directly connected, not the communication device on the network to be connected.

  When communication is performed with a communication device on a network other than the network to which the communication device 100 is directly connected, only the route information related to the virtual default gateway set in the virtual interface 102 is set in the route table 104. The packet is transmitted via the virtual interface 102 by the path control performed. Therefore, when a packet transmitted by a communication device on a network other than the network to which the communication device 100 is directly connected is received, it is necessary for the communication stack 103 to receive the packet via the virtual interface 102. .

  Therefore, when the network address obtained from the identified source IP address and the network address obtained from the IP address set in the communication interface that received the packet are not equal, the packet transfer rule generation unit 306 notifies the new flow detection notification. A packet transfer rule including the flow information included in the action information and the action information is generated. This action information includes the action of rewriting the destination MAC address to the virtual MAC address set in the virtual interface 102, the action of rewriting the destination IP address to the virtual IP address set in the virtual interface 102 (step S203), and the received action information. It consists of the action (step S204) which transmits a packet to the virtual interface 102.

  Packet transfer based on such packet transfer rules enables the communication stack 103 to receive the packet received by the packet transfer unit 200 via the virtual interface 102.

  When the network address obtained from the identified source IP address is equal to the network address obtained from the IP address set in the communication interface that received the packet (Yes in step S202), the identified source IP address is the packet. It is determined whether or not it is equal to the IP address set in the communication interface that has received (step S205).

  If the identified source IP address is not equal to the IP address set in the communication interface that received the packet (No in step S205), it is transmitted from the communication device on the network connected via the communication interface that received the packet. It can be determined that the packet is a packet. On the other hand, if the identified source IP address is equal to the IP address set in the communication interface that received the packet (Yes in step S205), it can be determined that the packet is transmitted by the communication program 105.

  When the identified source IP address is not equal to the IP address set in the communication interface that received the packet (No in step S205), the packet transfer rule generation unit 306 includes flow information included in the new flow detection notification, A packet transfer rule including action information including an action (step S206) for transmitting the received packet to the communication stack 103 is generated.

  By packet transfer based on such a packet transfer rule, the packet received by the packet transfer unit 200 can be received via the communication interface from which the communication stack 103 has received the packet.

  If the identified source IP address is equal to the IP address set in the communication interface that received the packet (Yes in step S205), the destination MAC address of the received packet based on the flow information included in the new flow detection notification Is identified. Then, it is determined whether the identified destination MAC address is equal to the MAC address of the virtual default gateway set in the virtual interface 102 (step S207).

  When the identified transmission destination MAC address is equal to the MAC address of the virtual default gateway (Yes in step S207), the communication program 105 assigns a virtual default gateway to a communication device on a network other than the network to which the communication device 100 is directly connected. It can be determined that the packet is transmitted through the network. On the other hand, if the identified destination MAC address and the MAC address of the virtual default gateway are not equal (No in step S207), the communication program 105 transmits to the communication device on the network connected via the communication interface that received the packet. It can be determined that the packet is directly transmitted.

  If the identified destination MAC address and the MAC address of the virtual default gateway are equal (Yes in step S207), the packet transfer rule generation unit 306 determines the flow of the received packet based on the flow information included in the new flow detection notification. Used interface information including flow information conforming to the above is acquired through the used interface information management unit 302. Then, based on information that can uniquely identify any of the plurality of communication interfaces 101 included in the acquired use interface information, a communication interface to be used for communication is specified (step S208). Note that the communication interface used for communication is one of the plurality of communication interfaces 101.

  In addition, the address information of the communication interface used for the specified communication is acquired through the address information management unit 304 (step S209).

  The virtual default gateway is a default gateway on a virtual network inside the communication apparatus 100 connected via the virtual interface 102. However, the virtual default gateway is a virtual existence having only the route information set in the route table 104 by the route table management unit 305. Accordingly, even if a packet to be transmitted to the virtual default gateway whose destination MAC address is the MAC address of the virtual default gateway received by the packet transfer unit 200 is transmitted to the communication interface used for communication, the packet is transmitted on the network used for communication. Since there is no virtual default gateway, a packet cannot be transmitted to a communication device on a network other than the network to which the communication device 100 is directly connected.

  In order to enable a packet to be transmitted to a communication device on a network other than the network to which the communication device 100 is directly connected using a network connected via a communication interface used for communication, a communication interface used for communication is used. It is necessary to transmit a packet to a default gateway on a network connected via the network, that is, a default gateway set in a communication interface used for communication.

  Therefore, by transferring the packet to be transmitted to the virtual default gateway to the default gateway on the network connected via the communication interface used for communication, the communication device 100 can communicate with a communication device on a network other than the network to which the communication device 100 is directly connected. Packets can be transmitted.

  Therefore, when the specified destination MAC address is equal to the MAC address of the virtual default gateway, the packet transfer rule generation unit 306 generates a packet transfer rule including the flow information and action information included in the new flow detection notification. To do. This action information includes an action for rewriting the source MAC address to a MAC address set for the communication interface used for communication, and an action for rewriting the source IP address to the IP address set for the communication interface used for communication (step S210). , The action of rewriting the destination MAC address to the MAC address of the default gateway set in the communication interface used for communication (step S211), and the action of transmitting the received packet to the communication interface used for communication (step S212). .

  By packet transfer based on such a packet transfer rule, a packet received by the packet transfer unit 200 is transmitted to a default gateway on a network connected via a communication interface used for communication.

  If the identified destination MAC address is not equal to the MAC address of the virtual default gateway (No in step S207), the source MAC address of the received packet is the MAC address set in the communication interface that received the packet. The source IP address of the packet is an IP address set in the communication interface that has received the packet, and the destination MAC address of the received packet is the destination on the network connected via the communication interface that has received the packet. Since the destination IP address of the packet is the IP address of the destination communication device on the network connected via the communication interface that received the packet, the communication interface that received the packet as it is. It may be transmitted from Esu.

  Accordingly, the packet transfer rule generation unit 306 includes a packet transfer rule including flow information included in the new flow detection notification and action information including an action (step S213) of transmitting the received packet to the communication interface that has received the packet. Is generated.

  By packet transfer based on such a packet transfer rule, the packet received by the packet transfer unit 200 is transmitted from the communication interface that received the packet to the destination communication device.

  Prior to packet transmission, the communication stack 103 needs to perform address resolution to obtain the MAC address of the destination communication device based on the IP address of the destination communication device. When communication device 100 communicates with a communication device on a network connected via a plurality of communication interfaces 101, the MAC address of the destination communication device may be obtained by a normal address resolution method on each communication interface. . On the other hand, when communication is performed with a communication device on a network other than the network to which the communication device 100 is directly connected, the communication stack 103 transmits a packet via the virtual default gateway. The packet transfer rule generation unit 306 generates a packet transfer rule for transmitting a packet transmitted to the virtual default gateway by the communication stack to a default gateway on a network connected via a communication interface used for communication. . Therefore, an address resolution method for obtaining not only the MAC address of the virtual default gateway but also the MAC address of each default gateway set for each communication interface of the plurality of communication interfaces 101 is required.

  In the address resolution process, two types of address resolution packets are transmitted and received. The two types of address resolution packets are a request for an address resolution request packet for requesting a communication apparatus to obtain a MAC address to transmit a MAC address and a communication apparatus that has made the request. In response, it is an address resolution response packet for transmitting a response including the MAC address. The address resolution request packet is, for example, an ARP (Address Resolution Protocol) request packet. The address resolution response packet is, for example, an ARP reply packet.

  The address resolution request packet is at least a source MAC address, a destination MAC address, a request source communication device, specifically, a request source MAC address that is a MAC address and an IP address of a communication device that transmits an address resolution request packet. And the request source IP address, the request destination communication device, specifically, the request destination MAC address and the request destination IP address which are the MAC address and IP address of the communication device to obtain the MAC address. Note that since the transmission destination MAC address and the request destination MAC address are unknown at the time of making the address resolution request, the values of those MAC addresses are arbitrary MAC address values. For example, the transmission destination MAC address is a broadcast address, and the request destination MAC address is an empty value.

  The address resolution response packet is at least a source MAC address, a destination MAC address, a response source communication device, specifically, a response source MAC address that is a MAC address and an IP address of a communication device that transmits the address resolution response packet. And the response source IP address, the response destination communication device, specifically, the response destination MAC address and the response destination IP which are the MAC address and IP address of the communication device that has transmitted the address resolution request packet to which the address resolution response packet should be transmitted Contains an address. Note that the MAC address of the communication device to be obtained by the address resolution request is the response source MAC address included in the address resolution response packet.

  Since the virtual default gateway is a virtual existence that exists only on the routing table 104, even if an address resolution request packet is transmitted to the virtual default gateway, an address resolution response packet including the MAC address of the virtual default gateway is received. Never sent. Further, since the route information related to the default gateway set for the communication interface used for communication does not exist on the route table 104, the address resolution request packet is sent to the default gateway set for the communication interface used by the communication stack 103 for communication. Never send. Therefore, the transfer control unit 300 performs processing for obtaining the MAC address of the virtual default gateway and the MAC address of the default gateway set in the communication interface used for communication.

  A process for obtaining the MAC address of the virtual default gateway and the MAC address of the default gateway set in the communication interface used for communication will be described. When the packet transfer unit 200 receives the address resolution request packet for the virtual default gateway transmitted by the communication stack 103, specifically, a new flow when the packet transfer unit 200 receives the address resolution request packet for the virtual default gateway. When the transfer control unit 300 receives the detection notification, the transfer control unit 300 acquires address information of each communication interface of the plurality of communication interfaces 101 through the address information management unit 304, and a default gateway set for each communication interface IP address is obtained. Then, an address resolution request packet for each default gateway is generated and transmitted to the packet transfer unit 200 together with an instruction to transmit the generated packet to each communication interface. The packet transfer unit 200 transmits an address resolution request packet for each default gateway according to the instruction.

  Note that, when an address resolution request packet for the virtual default gateway is received, a new flow detection notification is transmitted from the packet transfer unit 200. Therefore, the packet transfer rule for the address resolution request packet flow for the virtual default gateway is: It is not set in the transfer unit 200. It is assumed that the new flow detection notification for the address resolution request packet flow to the virtual default gateway includes the address resolution request packet itself.

  When the packet transfer unit 200 transmits an address resolution request packet for each default gateway, an address resolution response packet including the MAC address of each default gateway is transmitted from each default gateway to the communication apparatus 100. When the packet transfer unit 200 receives an address resolution response packet including the MAC address of each default gateway, specifically, the packet transfer unit 200 receives an address resolution response packet including the MAC address of each default gateway. When the transfer control unit 300 receives the new flow detection notification, the MAC address of each default gateway is acquired based on the flow information included in the new flow detection notification, and the MAC address of each acquired default gateway is acquired. Is stored in the address information storage unit 303 through the address information management unit 304.

  When an address resolution response packet including the MAC address of each default gateway is received, a new flow detection notification is transmitted from the packet forwarding unit 200, so that the address resolution response packet including the MAC address of each default gateway is transmitted. The packet transfer rule for the flow is not set in the packet transfer unit 200. It is assumed that the new flow detection notification for the address resolution response packet flow transmitted from each default gateway includes the address resolution response packet itself.

  Then, when the address resolution response packet is received from all the default gateways and the MAC addresses of all the default gateways are obtained, the virtual default gateway that is a virtual MAC address composed of an arbitrary value set in advance in the transfer control unit 300 An address resolution response packet including the MAC address is generated, and the generated packet is transmitted to the virtual interface 102.

  By performing the processing as described above, the MAC address of the virtual default gateway necessary for the communication stack 103 to transmit the packet and the packet transfer rule generation unit 306 used for communication necessary for generating the packet transfer rule The MAC address of the default gateway set in the communication interface to be obtained can be obtained.

  For the MAC address of the virtual default gateway, by registering the virtual MAC address in advance in the address resolution table of the communication stack 103 as the MAC address corresponding to the IP address of the virtual default gateway, the communication stack 103 has the virtual default gateway. A MAC address may be obtained. Further, after obtaining the MAC address of each default gateway set for each communication interface of the plurality of communication interfaces 101 by an arbitrary method, each default gateway corresponding to the IP address of each default gateway in the address resolution table. The MAC address of each default gateway obtained by the address information management unit 304 referring to the address resolution table in the address information storage unit 303 is stored in the address information storage unit 303 in advance. 306 may be able to obtain the default gateway MAC address needed to generate the packet forwarding rules. However, in that case, when a change occurs in the address information of the communication interface, the contents of the address resolution table must also be changed.

  In the above address resolution processing, when an address resolution request packet for the virtual default gateway is received, an address resolution response packet including a virtual MAC address that is the MAC address of the virtual default gateway is generated, and the generated packet is transmitted to the virtual interface 102. May be sent to. In this case, however, communication cannot be performed until the address resolution response packet transmitted from each default gateway is received and the MAC address of each default gateway corresponding to the IP address of each default gateway is obtained.

  The packet transfer unit management unit 307 manages the packet transfer unit 200 using an arbitrary protocol for controlling the operation of the packet transfer unit 200. When the packet transfer rule generation unit 306 generates a packet transfer rule, the packet transfer unit management unit 307 transmits the generated packet transfer rule to the packet transfer unit 200 together with a setting instruction.

  In the packet transfer rule generation process of the packet transfer rule generation unit 306, the use interface information including flow information that matches the flow of the received packet may not exist in the use interface information storage unit 301. In that case, any of the plurality of communication interfaces 101 may be set in advance as a default communication interface, and the packet transfer rule may be generated as a communication interface that uses the communication interface for communication. In addition, default action information including arbitrary actions such as discarding a packet is set in advance, and a packet transfer rule is generated based on the flow information included in the new flow detection notification and the default action information. Also good.

  In addition, information of a nonexistent communication interface was set in information that can uniquely identify any of the plurality of communication interfaces 101 included in the use interface information including flow information that matches the flow of the received packet. In this case, default action information for such use interface information including an arbitrary action such as discarding a packet is set in advance, and based on the flow information included in the new flow detection notification and the default action information. A packet transfer rule may be generated.

  Further, the address information of each communication interface of the plurality of communication interfaces 101 may not include default gateway information, specifically, the IP address of the default gateway. When a communication interface that does not include default gateway information in the address information is used, communication with a communication device on a network other than the network to which the communication device 100 is directly connected cannot be performed. In such a case, the used interface information management unit 302 may take a countermeasure so that the used interface information that defines the use of the communication interface that does not include the default gateway information in the address information cannot be set. Further, default action information for such use interface information including an arbitrary action such as discarding a packet may be set in advance, and a packet transfer rule may be generated based on the default action information.

  When the use interface information stored in the use interface information storage unit 301 is changed through the use interface information management unit 302 by the user or an arbitrary program, the packet transfer rule generated based on the changed use interface information is also changed. There is a need.

  When the used interface information is changed, the transfer control unit 300 stores all packet transfer rules that match the flow information included in the changed used interface information in the packet transfer rule storage unit 201 of the packet transfer unit 200. Is acquired from the packet transfer rule table through the packet transfer unit management unit 307, the content of each acquired packet transfer rule is changed to content based on the changed used interface information, and each changed packet transfer rule is A packet transfer rule is changed by transmitting to the packet transfer part 200 through the packet transfer part management part 307 with the setting instruction | indication which changes. Alternatively, all the packet transfer rules that match the flow information included in the changed used interface information may be deleted through the packet transfer unit management unit 307, and a response may be made so as to generate a new packet transfer rule.

  In the present embodiment, when an arbitrary communication program 105 operating on the communication device 100 communicates with a communication device on a network other than the network to which the communication device 100 is directly connected, the packet transmitted by the communication program 105 is It is transmitted to the virtual default gateway by the path control performed by the communication stack 103, and further connected via a communication interface used for communication specified by the used interface information set through the used interface information management unit 302 by the packet transfer unit 200. Forwarded to the default gateway on the network. When using a network connected via a communication interface other than the communication interface set to be superior, the method described in Patent Document 1 cannot communicate with a communication device on a network other than the network directly connected to the communication device. In contrast, in any case of using any of the networks connected via the plurality of communication interfaces 101, it is possible to communicate with a communication device on a network other than the network to which the communication device 100 is directly connected. .

  Further, in order to enable the communication program 105 to select a communication interface to be used for communication, no special measures such as changing the communication program 105 are required. From the network side, the communication device 100 seems to perform communication by a normal IP communication mechanism, and therefore, no special measures on the network side such as preparing a specific mechanism or an opposite communication device are required. In addition, communication can be performed without the need to register information of an arbitrary address of a specific communication device in advance.

  Further, since the communication program 105 seems to perform communication via the virtual interface 102 and the virtual default gateway regardless of the communication interface used for communication, the communication interface used for communication included in the used interface information. If the address information of the communication interface changes due to the DHCP lease expiration or the occurrence of a handover due to the movement of the communication device, the communication program 105 is made aware of it. It can be performed.

  By using the network control method in units of flows and by specifying the communication interface to be used for communication for each flow through the used interface information, the user or any program can be specified for each flow based on any request or condition. The network to be used for communication can be selected. In other words, traffic transmitted and received by communication programs with different communication characteristics is considered to be a set of several flows, so communication programs that operate on a communication device with a finer granularity of flow units use it for communication. It can be said that the network can be arbitrarily selected.

  For example, the traffic of a communication program in which a user transmits / receives an electronic mail with a small communication volume, specifically, the destination port number is 25 (SMTP, Simple Mail Transfer Protocol) or 110 (POP3, Post Office Protocol version 3). ) For the flow of communication program that sets the use interface information that defines the use of the 3G network and performs communication with a large amount of traffic such as video streaming on the Web, specifically, the transmission destination For the flow with port number 80 (HTTP, HyperText Transfer Protocol), use interface information that determines the use of the wireless LAN network is set. Embodiments of the present invention, the traffic of each communication program is as communication is performed using a network of 3G and wireless LAN.

  For example, when the user does not permit communication with a communication device on an arbitrary network, specifically, for a flow in which the source IP address or the destination IP address is the IP address of a communication device that does not permit communication By setting use interface information that defines the use of a non-existing communication interface, according to the embodiment of the present invention, it is possible to discard a packet transmitted / received to / from a communication device that does not permit communication.

  For example, a program that operates on the communication device 100 that monitors whether or not each communication interface of the plurality of communication interfaces 101 can communicate dynamically sets use interface information based on the state of each communication interface. A network used for communication by a flow of an arbitrary communication program can be dynamically changed. When the wireless LAN network is disconnected and communication becomes impossible, the usage interface information that defines the use of the wireless LAN network is changed to the usage interface information that defines the use of the 3G network. Thus, the flow of an arbitrary communication program comes to communicate using the 3G network.

  For example, a program that operates on the communication device 100 that monitors the reception field strength of the wireless interface included in the plurality of communication interfaces 101 may receive a reception field strength that is greater than a predetermined threshold based on the reception field strength of each wireless interface. By selecting a wireless interface having a large communication interface as a communication interface to be used for communication and setting use interface information that defines the use of the wireless interface, according to the embodiment of the present invention, the flow of an arbitrary communication program is the most Communication is performed using a wireless interface that is considered to have good communication quality.

  For example, a program that operates on the communication device 100 that monitors the number of packet transmission / reception of each communication interface of the plurality of communication interfaces 101 is based on the number of packet transmission / reception of each communication interface and a predetermined upper limit of the number of packet transmission / reception, When the number of packet transmission / reception of the communication interface used for communication by the flow of an arbitrary communication program reaches the upper limit, this interface can be set by setting the use interface information that defines the use of another communication interface or a non-existing communication interface. According to an embodiment of the present invention, for a flow of an arbitrary communication program using a communication interface whose number of packet transmission / reception has reached the upper limit, communication is performed using another communication interface, or a packet is discarded. To respond It can be carried out.

(Second Embodiment)
FIG. 8 is a block diagram illustrating a more detailed configuration example of the communication apparatus focusing on elements related to communication in the second embodiment. Constituent elements similar to those of the communication device in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. The packet transfer unit 200 of the communication device 100 according to the second embodiment configures a structure such as a bridge inside the communication device 100. In the second embodiment, a case where the packet transfer unit 200 forms a bridge will be described as an example.

  When the packet transfer unit 200 forms a bridge, the communication stack 103 needs to transmit and receive packets using the virtual interface 102 connected to the bridge formed by the packet transfer unit 200, specifically, a local port of the bridge as an end point. is there. Therefore, as in the first embodiment, each communication interface of the plurality of communication interfaces 101 is connected to the communication stack 103, and the communication stack 103 cannot transmit and receive packets via the plurality of communication interfaces 101. Therefore, even if the packet transfer method performed by the packet transfer unit 200 and the transfer control unit 300 described in the first embodiment is directly applied to the communication device 100 in the second embodiment, the packet transfer unit 200 and the transfer control unit 300 are connected via the plurality of communication interfaces 101. Cannot communicate using the connected network.

  Therefore, in the second embodiment, setting the IP address of the virtual interface 102 and communication for enabling the communication stack 103 to transmit and receive packets via the virtual interface 102 with the virtual interface 102 as an end point. By setting the routing table 104 of the stack 103 and performing packet transfer by the packet transfer unit 200 and the transfer control unit 300 based on those settings, the communication stack of the communication device communicates with one of the communication interfaces as an end point. Even when it is necessary to perform communication, it is possible to perform communication using a network connected through a plurality of communication interfaces provided in the communication device.

  The communication device 100 in the second embodiment includes a plurality of communication interfaces 101 and a virtual interface 102 as in the first embodiment, but only the virtual interface 102 is connected to the communication stack 103 of the communication device 100. The A plurality of communication interfaces 101 and virtual interfaces 102 are connected to the packet transfer unit 200.

  With the configuration illustrated in FIG. 8, the packet transfer unit 200 can receive a packet transmitted from the communication program 105 operating on the communication device 100 from the virtual interface. In addition, a packet transmitted from another communication device can be received from any one of the plurality of communication interfaces 101.

  At the point before packet transfer by the packet transfer unit 200 and transfer control unit 300 in the second embodiment, the virtual interface 102 has virtual address information consisting of an arbitrary value as in the first embodiment. Is set. The address information of the virtual interface 102 includes at least a virtual MAC address, a virtual IP address, and a MAC address and an IP address of a virtual default gateway.

  The address information management unit 304 in the second embodiment acquires the address information of each communication interface of the plurality of communication interfaces 101 connected to the packet transfer unit 200 and the address information of the virtual interface 102 and stores them in the address information storage unit 303. Remember. Furthermore, the IP address of each communication interface included in the address information of each communication interface of the acquired plurality of communication interfaces 101 is set in the virtual interface 102. That is, one or more IP addresses, specifically, a virtual IP address and an IP address set for each communication interface of the plurality of communication interfaces 101 are set in the virtual interface 102 in the second embodiment. .

  The routing table management unit 305 according to the second embodiment is set to the default gateway set for each communication interface of the plurality of communication interfaces 101 included in the address information stored in the address information storage unit 305 and the virtual interface 102. Among the virtual default gateways, only the route information related to the virtual default gateway is set in the route table 104 of the communication stack 103. Further, the route table management unit 305 deletes route information regarding the route to each network connected via the plurality of communication interfaces 101 whose output interfaces are each communication interface of the plurality of communication interfaces 101 from the route table 104, Instead of the route information, route information related to routes to each network connected via the plurality of communication interfaces 101 whose output interfaces are virtual interfaces is set in the route table 104.

  FIG. 9 is a configuration example of a routing table in the second embodiment. The routing table 104 is set as shown in FIG. 9 by the routing table management unit 305 in the second embodiment. Unlike the first embodiment, the route information regarding the route to each network connected via the plurality of communication interfaces 101 is each network to which the destination network is connected via the plurality of communication interfaces 101, and the output interface. Is set to be virtual interface. Further, as route information regarding a route to a virtual network connected via the virtual interface 102, route information in which the destination network is a virtual network and the output interface is a virtual interface is set. Furthermore, only route information that is a virtual default gateway in which the next hop is set in the virtual interface is set as route information related to the default gateway.

  The route information related to the default gateway set in the route table 104 is not only the route information related to the virtual default gateway set in the virtual interface 102 but also the route related to the default gateway set for each communication interface of the plurality of communication interfaces 101. Information may be set. However, in that case, route information regarding the virtual default gateway is set to be superior.

  Further, with respect to route information related to routes to each network connected via a plurality of communication interfaces 101 set in the route table 104, routes to each network connected via a plurality of communication interfaces 101 whose output interfaces are virtual interfaces. In addition to the route information related to the route information, the route information related to the route to each network connected via the plurality of communication interfaces 101 which are the communication interfaces of the plurality of communication interfaces 101 may be set. However, in that case, the route information regarding the route to each network connected via the plurality of communication interfaces 101 whose output interfaces are virtual interfaces is preferentially set.

  By setting the IP address of the virtual interface 102 and the routing table 104 as described above, the packet transmitted from the communication program 105 is transmitted via the virtual interface 102 by the path control performed by the communication stack 103. It becomes like this. Specifically, not only when communicating with a communication device on a network other than the network to which the communication device 100 is directly connected, but also with a communication device on a network connected via a plurality of communication interfaces 101. Even in this case, the packet is transmitted via the virtual interface 102.

  When the communication program 105 communicates with a communication device on a network other than the network to which the communication device 100 is directly connected, after the path control is performed in the communication stack 103, the packet transfer unit 200 is transmitted from the communication program 105. When the received packet is received from the virtual interface 102, the source MAC address of the packet is the virtual MAC address set in the virtual interface 102, the destination MAC address of the packet is the MAC address of the virtual default gateway, The source IP address is the virtual IP address set in the virtual interface 102, and the destination IP address of the packet is the IP address of the destination communication device.

  On the other hand, when the communication program 105 communicates with a communication device on a network connected via a plurality of communication interfaces 101, the packet transfer unit 200 transmits from the communication program 105 after path control is performed in the communication stack 103. When the received packet is received from the virtual interface 102, the source MAC address of the packet is the virtual MAC address set in the virtual interface 102, and the destination MAC address of the packet is the MAC of the communication device that is the destination The source IP address of the packet becomes the IP address of the communication interface connected to the network where the destination communication device set in the virtual interface 102 by the address information management unit 304 exists, and the destination IP of the packet Address It will IP address of the destination communication device.

  Next, a packet transfer rule generation method in the packet transfer rule generation unit 306 of the second embodiment will be described. FIG. 10 is a flowchart illustrating an example of processing in which the transfer control unit according to the second embodiment generates a packet transfer rule.

  When the packet transfer rule generation unit 306 receives the new flow detection notification, the packet transfer rule generation unit 306 refers to the flow information included in the new flow detection notification and identifies the communication interface that has received the packet based on the reception port number included in the flow information. . Then, the address information of the communication interface that has received the packet and the address information of the virtual interface 102 are acquired through the address information management unit 304 (step S301). Note that the communication interface that has received the packet specified by the reception port number included in the flow information is one of the plurality of communication interfaces 101 and the virtual interface 102.

  Next, the packet transfer rule generation unit 306 refers to the flow information included in the new flow detection notification and identifies the source IP address of the received packet. Then, based on the subnet mask included in the address information of the communication interface that received the packet, the network address obtained from the identified source IP address is the IP of each communication interface of the plurality of communication interfaces 101 set in the virtual interface 102. It is determined whether it is equal to one of the network addresses obtained from the address (step S302). That is, based on the source IP address of the received packet, it is determined whether or not the packet is a packet transmitted from a communication device on the network connected via the communication interface that received the packet.

  When the network address obtained from the identified source IP address is not equal to any of the network addresses obtained from the IP addresses of the communication interfaces 101 of the plurality of communication interfaces 101 set in the virtual interface 102 (No in step S302). It can be determined that the packet is transmitted from a communication device on a network other than the network to which the communication device 100 is directly connected, not the communication device on the network connected via the communication interface that has received the packet.

  When communication is performed with a communication device on a network other than the network to which the communication device 100 is directly connected, only the route information related to the virtual default gateway set in the virtual interface 102 is stored in the route table 104 as in the first embodiment. Therefore, the packet is transmitted from the virtual interface 102 by route control performed by the communication stack 103. Therefore, when a packet transmitted by a communication device on a network other than the network to which the communication device 100 is directly connected is received, it is necessary for the communication stack 103 to receive the packet via the virtual interface 102. .

  Therefore, if the network address obtained from the identified source IP address is not equal to any of the network addresses obtained from the IP addresses of the communication interfaces 101 of the plurality of communication interfaces 101 set in the virtual interface 102, packet transfer rule generation is performed. The unit 306 generates a packet transfer rule including flow information included in the new flow detection notification and action information. This action information includes an action of rewriting the destination IP address to the virtual IP address set in the virtual interface 102 (step S303), and an action of rewriting the destination MAC address to the virtual MAC address set in the virtual interface 102 (step S304). , And an action (step S305) for transmitting the received packet to the virtual interface 102.

  Packet transfer based on such packet transfer rules enables the communication stack 103 to receive the packet received by the packet transfer unit 200 via the virtual interface 102.

  When the network address obtained from the identified source IP address is equal to one of the network addresses obtained from the IP addresses of the communication interfaces 101 of the plurality of communication interfaces 101 set in the virtual interface 102 (Yes in step S302) ), It is determined whether or not the identified source IP address is equal to any of the IP addresses of the communication interfaces of the plurality of communication interfaces 101 set in the virtual interface 102 (step S306).

  When the identified source IP address is not equal to any of the IP addresses of the communication interfaces 101 of the plurality of communication interfaces 101 set in the virtual interface 102 (No in step S306), connection is established via the communication interface that has received the packet. It can be determined that the packet is transmitted from a communication device on the network. On the other hand, when the identified source IP address is equal to any of the IP addresses of the communication interfaces of the plurality of communication interfaces 101 set in the virtual interface 102 (Yes in step S306), the packet transmitted by the communication program 105 It can be judged that.

  When the identified transmission source IP address is not equal to any of the IP addresses of the communication interfaces of the plurality of communication interfaces 101 set in the virtual interface 102 (No in step S306), in the communication apparatus 100 in the second embodiment. Even when communication is performed with a communication device on a network connected via a plurality of communication interfaces 101, a packet is transmitted via the virtual interface 102. Therefore, even when a packet transmitted by a communication device on a network connected via a plurality of communication interfaces 101 is received, it is necessary for the communication stack 103 to receive a packet via the virtual interface 102. It is.

  Therefore, the packet transfer rule generation unit 306 performs the action of rewriting the flow information included in the new flow detection notification, the destination MAC address to the virtual MAC address set in the virtual interface 102 (step S304), and the received packet as a virtual A packet transfer rule including action information including an action (step S305) to be transmitted to the interface 102 is generated.

  Packet transfer based on such packet transfer rules enables the communication stack 103 to receive the packet received by the packet transfer unit 200 via the virtual interface 102.

  When the identified transmission source IP address is equal to one of the IP addresses of the communication interfaces of the plurality of communication interfaces 101 set in the virtual interface 102 (Yes in step S306), the flow information included in the new flow detection notification Based on the above, the destination MAC address of the received packet is specified. Then, it is determined whether the identified destination MAC address is equal to the MAC address of the virtual default gateway set in the virtual interface 102 (step S307).

  When the identified destination MAC address is equal to the MAC address of the virtual default gateway (Yes in step S307), the communication program 105 assigns a virtual default gateway to a communication device on a network other than the network to which the communication device 100 is directly connected. It can be determined that the packet is transmitted through the network. On the other hand, when the specified destination MAC address and the MAC address of the virtual default gateway are not equal (No in step S307), the communication program 105 is connected via any one of the plurality of communication interfaces 101. It can be determined that the packet is transmitted directly to the communication device on the network.

  When the identified destination MAC address is equal to the MAC address of the virtual default gateway (Yes in step S307), the packet transfer rule generation unit 306 determines the flow of the received packet based on the flow information included in the new flow detection notification. Used interface information including flow information conforming to the above is acquired through the used interface information management unit 302. Then, based on information that can uniquely identify any of the plurality of communication interfaces 101 included in the acquired use interface information, a communication interface to be used for communication is specified (step S308). Note that the communication interface used for communication is one of the plurality of communication interfaces 101.

  In addition, the address information of the communication interface used for the specified communication is acquired through the address information management unit 304 (step S309).

  Then, in order to transfer the packet to be transmitted to the virtual default gateway to the default gateway on the network connected via the communication interface used for communication, the packet transfer rule generation unit 306 includes a flow included in the new flow detection notification. A packet transfer rule including information and action information is generated. This action information includes an action for rewriting the source MAC address to the MAC address set for the communication interface used for communication, and an action for rewriting the source IP address to the IP address set for the communication interface used for communication (step S310). , The action of rewriting the destination MAC address to the MAC address of the default gateway set in the communication interface used for communication (step S311), and the action of transmitting the received packet to the communication interface used for communication (step S312). .

  By packet transfer based on such a packet transfer rule, a packet received by the packet transfer unit 200 is transmitted to a default gateway on a network connected via a communication interface used for communication.

  A network to which the communication program 105 connects via any one of the plurality of communication interfaces 101 when the identified destination MAC address and the MAC address of the virtual default gateway are not equal (No in step S307) It can be determined that the packet is to be transmitted to the upper communication device. In the first embodiment, a plurality of communication interfaces 101 are connected to the communication stack 103, and the communication stack 103 can transmit and receive packets using the plurality of communication interfaces 101. Therefore, when communication is performed with a communication device on a network connected via a plurality of communication interfaces 101, the packet is transmitted via the communication interface connected to the network where the communication device of the transmission destination exists by path control performed by the communication stack 103. Therefore, the packet transfer unit 200 was able to identify the communication interface that received the packet, that is, the communication interface used for communication by the reception port number included in the flow information. However, in the second embodiment, since the packet is transmitted through the virtual interface 102 by the path control performed by the communication stack 103, the communication interface used for communication is specified by the reception port number included in the flow information. I can't. Therefore, even when communication is performed with a communication device on a network connected via a plurality of communication interfaces 101, it is necessary to specify a communication interface used for communication.

  In the second embodiment, the IP address of each communication interface of the plurality of communication interfaces 101 is set in the virtual interface 102, and each network connected via the plurality of communication interfaces 101 whose output interfaces are virtual interfaces. By setting the route information on the route in the route table 104, after the route control is performed in the communication stack 103, when the packet transfer unit 200 receives the packet, the source IP address of the packet is the destination address. This is the IP address of the communication interface connected to the network where the communication device exists. Therefore, the communication interface used for communication can be specified based on the source IP address of the packet.

  If the identified destination MAC address and the MAC address of the virtual default gateway are not equal, the packet transfer rule generation unit 306 acquires the address information of each communication interface of the plurality of communication interfaces 101 through the address information management unit 304. (Step S313).

  Then, based on the flow information included in the new flow detection notification, the source IP address of the received packet is specified, and the specified source IP address and the set IP address are the same among the plurality of communication interfaces 101 Any one of the communication interfaces is specified as a communication interface used for communication (step S314).

  Based on the communication interface used for the identified communication, the packet transfer rule generation unit 306 generates a packet transfer rule including the flow information included in the new flow detection notification and the action information. This action information includes the action of rewriting the source MAC address to the MAC address set in the communication interface used for communication (step S315) and the action of transmitting the received packet to the communication interface used for communication (step S316). Become.

  By packet transfer based on such a packet transfer rule, the packet received by the packet transfer unit 200 is transmitted from the communication interface connected to the network where the transmission destination communication device exists to the transmission destination communication device.

  As in the first embodiment, the communication stack 103 according to the second embodiment obtains the MAC address of the destination communication device based on the IP address of the destination communication device prior to packet transmission. Perform address resolution. However, unlike the first embodiment, the communication device 100 according to the second embodiment transmits and receives packets via the virtual interface 102, and thus performs address resolution directly on each communication interface of the plurality of communication interfaces 101. I can't do it. For this reason, in the normal address resolution method, it is not only possible to obtain the MAC address of the destination communication device, but also to respond to an address resolution request transmitted from another communication device.

  Therefore, the transfer control unit 300 in the second embodiment performs processing for enabling address resolution in the communication device 100 in the second embodiment. FIG. 11 is a flowchart illustrating an example of address resolution processing of the transfer control unit in the second embodiment.

  When the packet transfer unit 200 receives the address resolution packet, the packet transfer unit 200 transmits a new flow detection notification for the address resolution packet flow to the transfer control unit 300 (step S401). In the address resolution processing of the transfer control unit 300 in the second embodiment, when an address resolution packet is received, a packet for the flow of the address resolution packet is transmitted so that a new flow detection notification is transmitted from the packet transfer unit 200. The transfer rule is not set in the packet transfer unit 200. It is assumed that the new flow detection notification for the address resolution packet flow includes the address resolution packet itself.

  When receiving a new flow detection notification for the address resolution packet flow, the transfer control unit 300 acquires the address information of each communication interface of the plurality of communication interfaces 101 and the address information of the virtual interface 102 through the address information management unit 304. (Step S402). Then, referring to the contents of the address resolution packet, it is determined whether the received address resolution packet is an address resolution request packet or an address resolution response packet (step S403).

  If the received address resolution packet is an address resolution request packet (“request” in step S403), the request destination IP address included in the address resolution request packet is referred to, and the request destination IP address and the plurality of communication interfaces 101 Whether or not the received address resolution request packet is an address resolution request packet for the communication device 100 based on whether or not the IP address of any one of the communication interfaces is equal, specifically, a plurality of communication interfaces 101 It is determined whether it is an address resolution request packet for each communication interface (step S404).

  When it is an address resolution request packet for each communication interface of the plurality of communication interfaces 101 (Yes in step S404), the address resolution request packet is received as an address resolution response packet for the requesting communication apparatus that has transmitted the address resolution request packet An address resolution response packet including the communication interface MAC address is generated. The reason is that when the received address resolution request packet is transferred to the virtual interface 102 and an address resolution response packet is generated by the address resolution processing of the communication stack 103, it is not the MAC address of the communication interface that received the address resolution request packet. This is because the virtual MAC address set in the virtual interface 102 is included in the address resolution response packet.

  The transfer control unit 300 generates an address resolution response packet for the requesting communication device (step S405), and transmits the generated packet to the packet transfer unit 200 together with an instruction to transmit the generated packet to the communication interface that received the address resolution request packet. To do. The packet transfer unit 200 transmits the generated packet according to the instruction (step S406).

  An address resolution response packet including the MAC address of the communication interface that has received the address resolution request packet is generated as an address resolution response packet for the request source communication apparatus, and is transmitted from the communication interface that has received the packet to the request source communication apparatus. Thus, it is possible to respond to an address resolution request from another communication device.

  Further, since the address resolution request packet transmitted from another communication device is not transferred to the virtual interface 102 by performing the above processing, the request is received from the virtual interface 102 by the address resolution processing of the communication stack 103. An address resolution response packet for the original communication device is not transmitted.

  If the received address resolution request packet is not an address resolution request packet for each communication interface of the plurality of communication interfaces 101 (No in step S404), the address transmitted by the communication stack 103 to the destination communication device via the virtual interface 102 It can be determined that it is a resolution request packet. If the communication interface that has received the address resolution request packet is other than the virtual interface 102, it can be determined that it is not an address resolution request packet for the communication device 100, so the received packet is discarded (not shown).

  When the received address resolution request packet is not an address resolution request packet for each communication interface of the plurality of communication interfaces 101, the transfer control unit 300 determines the request destination IP address included in the address resolution request packet and the MAC address of the virtual default gateway. Are equal to each other, it is determined whether the received address resolution request packet is an address resolution request packet for the virtual default gateway (step S407).

  When the received address resolution request packet is an address resolution request packet for the virtual default gateway (Yes in step S407), as in the first embodiment, an address resolution request for each default gateway set for each communication interface. I do. On the other hand, when the received address resolution request packet is not an address resolution request packet for the virtual default gateway (No in step S407), the communication stack 103 is connected to the network via the plurality of communication interfaces 101 via the virtual interface 102. It can be determined that the address resolution request packet is transmitted to the communication device.

  When the received address resolution request packet is an address resolution request packet for the virtual default gateway (Yes in step S407), the transfer control unit 300 generates an address resolution request packet for each default gateway set for each communication interface. Then, the generated packet is transmitted to the packet transfer unit 200 together with an instruction to transmit the generated packet from each communication interface (step S409). The packet transfer unit 200 transmits an address resolution request packet to each default gateway according to the instruction.

  When the packet transfer unit 200 receives an address resolution request packet for the virtual default gateway, by transmitting an address resolution request for each default gateway set for each communication interface from each communication interface of the plurality of communication interfaces 101, An address resolution response packet including the MAC address of each default gateway is transmitted from each default gateway to communication apparatus 100.

  If the received address resolution request packet is not an address resolution request packet for the virtual default gateway (No in step S407), the received address resolution request packet is sent from the communication stack 103 among the plurality of communication interfaces 101 via the virtual interface 102. Address resolution request packet sent to a communication device on the network connected via any one of the communication interfaces, and it is necessary to take measures to ensure that the address resolution request packet is sent to the requested communication device. It is.

  In the second embodiment, the IP address of each communication interface of the plurality of communication interfaces 101 is set in the virtual interface 102, and each network connected via the plurality of communication interfaces 101 whose output interfaces are virtual interfaces. Is set in the route table 104, the request source IP address included in the address resolution request packet transmitted by the communication stack 103 via the virtual interface 102 is obtained by the communication device that is trying to obtain the MAC address. This is the IP address of one of the plurality of communication interfaces 101 connected to the existing network. Accordingly, the communication interface used for communication can be specified based on the request source IP address.

  When the received address resolution request packet is not an address resolution request packet for the virtual default gateway, the transfer control unit 300 has a plurality of communication interfaces in which the request source IP address included in the address resolution request packet is equal to the set IP address. One of the communication interfaces 101 is specified as a communication interface used for communication (step S410).

  Based on the communication interface used for the identified communication, the source MAC address and the request source MAC address included in the received address resolution request packet are rewritten to the MAC address of the communication interface used for communication (step S411), and the source MAC The address resolution request packet in which the address and the request source MAC address are rewritten is transmitted to the packet transfer unit 200 together with an instruction to transmit to the communication interface used for communication. The packet transfer unit 200 transmits an address resolution request packet in which the source MAC address and the request source MAC address are rewritten according to the instruction (step S412).

  By identifying the communication interface used for communication based on the request source IP address, rewriting the source MAC address and the request source MAC address to the MAC address of the communication interface used for communication, and transmitting from the communication interface used for communication The address resolution request packet is transmitted to the requested communication device on the network connected via any one of the plurality of communication interfaces 101.

  When the received address resolution packet is an address resolution response packet (“response” in step S403), the response destination IP address and the plurality of communication interfaces 101 are referred to by referring to the response destination IP address included in the address resolution response packet. Whether or not the received address resolution response packet is an address resolution response packet for the communication device 100 based on whether or not the IP address of any one of the communication interfaces is equal, specifically, a plurality of communication interfaces 101 It is determined whether it is an address resolution response packet for each communication interface (step S413).

  If the received address resolution response packet is not an address resolution response packet for each communication interface of the plurality of communication interfaces 101 (No in step S413), if the communication interface that received the address resolution response packet is other than the virtual interface 102, the communication Since it can be determined that the packet is not an address resolution response packet for the apparatus 100, the received packet is discarded (S414).

  When an address resolution request packet is received from another communication device, an address resolution response packet including the MAC address of the communication interface that has received the packet is generated and transmitted to the request source communication device, and transmitted from the other communication device. Since the address resolution request packet is not transferred to the virtual interface 102, an address resolution response packet for another communication device is not transmitted from the virtual interface 102. Therefore, it is not necessary to consider the address resolution response packet transmitted from the virtual interface 102.

  If the received address resolution response packet is an address resolution response packet for each communication interface of the plurality of communication interfaces 101 (Yes in step S413), the response source IP address included in the address resolution response packet and the setting for each communication interface Address resolution transmitted by the default gateway set in any one of the plurality of communication interfaces 101 based on whether the IP address of each default gateway is equal or not. It is determined whether the packet is a response packet (step S415).

  When the received address resolution response packet is an address resolution response packet transmitted by the default gateway set in any one of the plurality of communication interfaces 101 (Yes in step S415), the first embodiment and Similarly, the MAC address of the default gateway that transmitted the address resolution response packet is stored, and the address resolution response related to the virtual default gateway is performed.

  Obtaining the MAC address of the default gateway that transmitted the address resolution response packet from the response source MAC address included in the address resolution response packet transmitted by the default gateway set in any one of the plurality of communication interfaces 101 Can do. The obtained MAC address of the default gateway is stored through the address information management unit 304 (step S416). Then, it is determined whether or not the MAC addresses of all default gateways have been obtained (step S417). When all the MAC addresses are obtained (Yes in step S417), the transfer control unit 300 includes the virtual MAC addresses of the virtual default gateway. An address resolution response packet is generated (step S418), and the generated packet is transmitted to the packet transfer unit 200 together with an instruction to transmit from the virtual interface 102 (step S419). The packet transfer unit 200 transmits an address resolution response packet including the virtual MAC address of the virtual default gateway according to the instruction.

  Necessary for the communication stack 103 to send a packet by generating an address resolution response packet including the MAC address of the virtual default gateway and sending it to the virtual interface 102 when the MAC addresses of all the default gateways are obtained. The MAC address of the virtual default gateway and the MAC address of the default gateway set in the communication interface used for communication necessary for the packet transfer rule generation unit 306 to generate the packet transfer rule can be obtained.

  When the received address resolution response packet is not the address resolution response packet transmitted by the default gateway set in any one of the plurality of communication interfaces 101 (No in step S415), communication is performed via the virtual interface 102. As a response to the address resolution request packet transmitted by the stack 103, it can be determined that it is an address resolution response packet transmitted from the requested communication device. The response destination IP address included in the address resolution response packet is the IP address of one of the plurality of communication interfaces 101 used when the address resolution request packet is transmitted to the request destination transmission apparatus. The communication stack 103 transmits an address resolution request packet via the virtual interface 102, so that the communication stack 103 can receive an address resolution response packet transmitted by the requested communication device via the virtual interface 102. Action is required.

  In this case, the transfer control unit 300 rewrites the transmission destination MAC address and the response destination MAC address included in the received address resolution response packet with the virtual MAC address of the virtual interface 102 (step S420), and transmits the transmission destination MAC address and the response destination. The address resolution response packet with the rewritten MAC address is transmitted to the packet transfer unit 200 together with an instruction to transmit to the virtual interface 102. The packet transfer unit 200 transmits an address resolution response packet in which the transmission destination MAC address and the response destination MAC address are rewritten in accordance with the instruction (step S421).

  By rewriting the transmission destination MAC address and the response destination MAC address included in the received address resolution response packet to the virtual MAC address of the virtual interface 102 and transmitting it to the virtual interface 102, the communication stack 103 passes through the virtual interface 102. It is possible to obtain the MAC address of a communication device on a network connected via a plurality of communication interfaces 101.

(Third embodiment)
In the first and second embodiments, a user or an arbitrary program communicates with the used interface information storage unit 301 through the used interface information management unit 302 by using which communication interface among the plurality of communication interfaces 101 for each flow. Use interface information, which is information for determining whether to perform communication, may be set, but a plurality of use interface information may be set to determine that communication is performed using different communication interfaces for the same flow. .

  FIG. 12 is a configuration example of the used interface information stored in the used interface information storage unit 302 in the third embodiment. The used interface information storage unit 302 stores a plurality of used interface information for the same flow. In the third embodiment, the user or an arbitrary program can set one or more use interface information for the flow for each flow.

  Of the plurality of used interface information for the same flow stored in the used interface information storage unit 302 in the third embodiment, each used interface information includes the same flow information and a plurality of communication interfaces 101 that are different from each other. Information that can uniquely specify any one of the plurality of communication interfaces 101 that specify any one of the communication interfaces. In that case, the use interface information used in generating the packet transfer rule, that is, the communication interface used for communication cannot be specified only by the flow information.

  Therefore, some arbitrary information is included in the used interface information as an index for identifying the used interface information. In the configuration example of FIG. 12, the used interface information is information that determines the priority of the used interface information and whether or not communication can be performed using the communication interface as an index for identifying the used interface information. Including the communication availability, the threshold value of the received electric field strength of the wireless interface, and the upper limit of the packet transmission / reception number of the communication interface.

  In the packet transfer by the packet transfer unit 200 and the transfer control unit 300 in the third embodiment, a new flow detection notification is received when the packet transfer unit 200 receives an arbitrary packet, as in the first and second embodiments. When the transfer control unit 300 receives the packet transfer rule, the packet transfer rule generation unit 306 in the third embodiment generates a packet transfer rule for the received packet flow. The received packet is a packet transmitted by the communication program 105 to a communication device on a network other than the network to which the communication device 100 is directly connected.

  Based on the flow information included in the new flow detection notification, the packet transfer rule generation unit 306 acquires the use interface information including the flow information that matches the received packet flow through the use interface information management unit 302. When there is only one used interface information including flow information that matches the acquired received packet flow, as in the first and second embodiments, a plurality of communication interfaces 101 included in the acquired used interface information. A communication interface to be used for communication is specified based on information that can uniquely specify any of the above. On the other hand, when there are a plurality of used interface information including flow information that matches the acquired received packet flow, the packet transfer rule is based on an index for identifying the used interface information included in each acquired used interface information. Identify the interface information used to generate

  For example, among the used interface information including the flow information that matches the flow of the plurality of acquired packets, the used interface information with the lowest priority value among the communication interfaces that can be communicated is represented by the packet transfer rule. It is specified as used interface information used in generation.

  For example, the packet transfer rule generation unit 306 refers to the value of the received electric field strength for each wireless interface included in the plurality of communication interfaces 101, and uses interface information including flow information that matches the flow of the acquired plurality of received packets. Of these, use interface information whose received field strength value of each radio interface is larger than a threshold included in use interface information that defines use of each radio interface is used as interface information used in generating a packet transfer rule. Identify.

  In addition, the packet transfer rule generation unit 306 refers to the packet transmission / reception count of each communication interface of the plurality of communication interfaces 101, and determines that the communication interface whose packet transmission / reception count reaches the upper limit included in the usage interface information is used. Information may be handled such that it is not used in generating a packet transfer rule.

  Then, based on the information that can uniquely specify any of the plurality of communication interfaces 101 included in the specified use interface information, the communication interface used for communication is specified, and the flow information included in the new flow detection notification Based on the address information of the communication interface used for the specified communication, a packet transfer rule for the received packet flow is generated.

  Packet transfer rules based on an index for identifying used interface information when multiple used interface information is set for the same flow, each of which defines that communication is performed using different communication interfaces. By identifying the used interface information used in the generation of the network, the communication device can communicate using a network suitable for any request or condition among the networks connected via a plurality of communication interfaces. Become.

(Fourth embodiment)
The communication device 100 according to the first and second embodiments is a communication device that uses a network control method in units of flows, and controls the packet transfer unit 200 that transfers received packets and the operation of the packet transfer unit 200. The packet transfer unit 200 and the transfer control unit 300 are connected by an arbitrary method. The packet transfer unit 200 and the transfer control unit 300 perform the packet transfer described in the first and second embodiments. However, the packet transfer unit 200 is stopped due to an operation stoppage of the transfer control unit 300 due to an error. When the connection with the transfer control unit 300 is disconnected, there is a problem that packet transfer cannot be performed and communication is disabled.

  Depending on the packet transfer unit, when the connection with the transfer control unit is disconnected, the function related to the network control method in units of flows is stopped, and communication can be performed by path control performed by the communication stack of the communication device. However, in the first and second embodiments, route information for enabling communication by packet transfer by the packet transfer unit 200 and the transfer control unit 300 is set in the route table 104. Even if the communication stack 103 performs path control using the path table 104, communication cannot be performed.

  In the first embodiment, only the route information whose next hop is the virtual default gateway is set as the route information related to the default gateway on the route table 104. Therefore, on the network other than the network to which the communication device 100 is directly connected. Communication with the communication device cannot be performed. In the second embodiment, as in the first embodiment, only route information whose next hop is a virtual default gateway is set as route information related to the default gateway on the route table 104. In addition, as route information regarding a route to each network connected via the plurality of communication interfaces 101 on the route table 104, the destination network is each network connected via the plurality of communication interfaces 101, and the output interface is virtual. The route information that is the interface 102 is set. Therefore, communication with not only a communication device on a network other than the network directly connected to the communication device 100 but also a communication device on each network connected via the plurality of communication interfaces 101 cannot be performed.

  Therefore, in the fourth embodiment, when the communication stack 103 of the communication device 100 has a plurality of route tables and the connection between the packet transfer unit 200 and the transfer control unit 300 is disconnected, the route control performed by the communication stack 103 is performed. By switching the routing table to be used, avoiding communication failure.

  FIG. 13 is a block diagram illustrating a configuration example of a communication device according to the fourth embodiment. Constituent elements similar to those of the communication device in the first and second embodiments are denoted by the same reference numerals, and detailed description thereof is omitted. The communication stack 103 according to the fourth embodiment includes a route table 104 used for enabling communication by packet transfer by the packet transfer unit 200 and the transfer control unit 300, and a route table 106 used when packet transfer cannot be performed. have. In addition, the communication device 100 according to the fourth embodiment includes a connection monitoring unit 400 that monitors the connection between the packet transfer unit 200 and the transfer control unit 300.

  Furthermore, as illustrated in FIG. 14, the communication stack 103 includes an address information storage unit 107, an address information management unit 108, and a route table management unit 109.

  The route table 104 used to enable communication by packet transfer by the packet transfer unit 200 and the transfer control unit 300 includes an address information storage unit 303, an address information management unit 304, and a route table management unit 305 of the transfer control unit 300. Thus, the configuration shown in FIG. 6 in the first embodiment or in FIG. 9 in the second embodiment is set. On the other hand, the routing table 106 used when packet transfer cannot be performed is shown in FIG. 15 by the address information storage unit 107, the address information management unit 108, and the routing table management unit 109 of the communication stack 103 in the fourth embodiment. The configuration is set as follows.

  Similar to the address information management unit 304, the address information management unit 108 acquires address information of each communication interface of the plurality of communication interfaces 101 and stores it in the address information storage unit 107. Further, the address information management unit 108 re-addresses the address information of the communication interface in which the change of the address information has occurred when the change of the address information occurs due to the DHCP lease expiration or the occurrence of a handover accompanying the movement of the communication device. Acquired and stored in the address information storage unit 107.

  Based on the address information stored in the address information storage unit 107, the routing table management unit 109 sets the routing table 106 used when packet transfer by the packet transfer unit 200 and the transfer control unit 300 cannot be performed. As route information regarding the route to each network connected via the plurality of communication interfaces 101 on the route table 106, the destination network is each network connected via the plurality of communication interfaces 101, and the output interface is each communication interface. Set the route information. In addition, as route information related to the default gateway on the route table 106, only the route information related to any of the default gateways among the default gateways whose next hop is set for each communication interface 101 is set.

  In addition, about the route information regarding the default gateway set in the route table 106, the route information regarding each default gateway set for each communication interface of the plurality of communication interfaces 101 may be set. However, in that case, one of the route information related to any of the default gateways among the default gateways set for each communication interface of the plurality of communication interfaces 101 is preferentially set.

  The route information related to the default gateway set in the route table 106 is determined by an arbitrary method. For example, any one of the plurality of communication interfaces 101 is set as a default communication interface in advance, and route information that is a default gateway whose next hop is set as a default communication interface is set.

  The connection monitoring unit 400 monitors the connection between the packet transfer unit 200 and the transfer control unit 300, and sets the communication stack 103 to switch the route table used for route control based on the connection state.

  When the packet transfer unit 200 and the transfer control unit 300 are connected, the connection monitoring unit 400 sets the communication stack 103 so as to perform route control using the route table 104. In that case, the configuration of the communication device 100 is the same as the configuration illustrated in FIG. 4 in the first embodiment or the configuration illustrated in FIG. 8 in the second embodiment. When the communication stack 103 performs path control using the path table 104, communication can be performed by packet transfer by the packet transfer unit 200 and the transfer control unit 300.

  When the connection monitoring unit 400 detects that the connection between the packet transfer unit 200 and the transfer control unit 300 is disconnected, the connection monitoring unit 400 sets the communication stack 103 so as to perform route control using the route table 106. When the connection between the packet transfer unit 200 and the transfer control unit 300 is disconnected, the packet transfer unit 200 and the transfer control unit are switched by switching the route table used for route control of the communication stack 103 from the route table 104 to the route table 106. Even when packet transfer by 300 is not possible, communication can be performed by route control of the communication stack 103.

  When the packet transfer unit 200 and the transfer control unit 300 are disconnected from each other and the packet transfer by the packet transfer unit 200 and the transfer control unit 300 cannot be performed, the configuration of the communication device 100 is as shown in FIG.

  Although communication is possible by the communication stack 103 performing route control using the route table 106, packet transfer cannot be performed by the packet transfer unit 200 and the transfer control unit 300. When any of the networks connected via the interface 101 is used, communication with a communication device on a network other than the network to which the communication device 100 is directly connected is performed, and a network used for communication for each flow is used. It cannot be selected. That is, in that case, it is equivalent to communication by a normal IP communication mechanism.

  Further, the connection monitoring unit 400 disconnects the packet transfer unit 200 and the transfer control unit 300, switches the route table used for route control of the communication stack 103 from the route table 104 to the route table 106, and then transfers the packet. Path table used by the communication stack 103 for path control so that communication is possible by packet transfer by the packet transfer unit 200 and the transfer control unit 300 when it is detected that the unit 200 and the transfer control unit 300 are connected. May be switched from the route table 106 to the route table 104.

  Further, in the fourth embodiment, the communication stack 103 is used when the packet transfer unit 200 and the transfer control unit 300 cannot perform packet transfer with the route table 104 used to enable communication by packet transfer. Although it has been described that the route table 106 to be used has two route tables, the number of route tables that the communication stack 103 has is not particularly limited and may be one or more. A plurality of route information relating to routes to each network connected via a plurality of communication interfaces 101 and route information relating to default gateways are set on one route table, and the connection state between the packet transfer unit 200 and the transfer control unit 300 On the basis of the above, appropriate route information may be set to be dominant, and the route information used for route control performed by the communication stack 103 may be switched.

  For example, as route information regarding a route to each network connected via a plurality of communication interfaces 101, a route in which a destination network is each network connected via a plurality of communication interfaces 101, and an output interface is each communication interface The route table 104 is set with route information in which the information and the destination network are each network connected via the plurality of communication interfaces 101 and the output interface is a virtual interface. In addition, as route information related to the default gateway, route information whose next hop is a default gateway among the default gateways set for each communication interface of the plurality of communication interfaces 101, and route information whose next hop is a virtual interface Is set in the routing table 104.

  When the packet transfer unit 200 and the transfer control unit 300 are connected, the destination network is connected via the plurality of communication interfaces 101 as route information regarding the route to each network connected via the plurality of communication interfaces 101. The route information whose output interface is a virtual interface is preferentially set, and the route information whose next hop is a virtual interface is preferentially set as route information related to the default gateway, whereby the packet transfer unit 200 and Communication can be performed by packet transfer by the transfer control unit 300.

  On the other hand, when the connection between the packet transfer unit 200 and the transfer control unit 300 is disconnected, the transmission destination network uses a plurality of communication interfaces 101 as route information regarding a route to each network connected through the plurality of communication interfaces 101. A default gateway in which route information is set for each communication interface of the plurality of communication interfaces 101 as the route information related to the default gateway. Even if packet transfer cannot be performed, communication can be performed by the path control performed by the communication stack 103 by preferentially setting the route information that is one of the default gateways.

  The embodiment of the present invention has been described above by way of example, but the present invention is not limited to this, and can be changed and modified in accordance with the purpose within the scope of the claims.

  As described above, according to the present invention, communication with a communication device on a network other than the network to which the communication device is directly connected in any of the networks connected via the communication interface provided in the communication device is used. And is suitable for communication devices having a plurality of communication interfaces, such as personal computers and smartphones. The

100 Communication Device 101 Multiple Communication Interfaces 102 Virtual Interface 103 Communication Stack 104 Routing Table 105 Communication Program 106 Routing Table 107 Address Information Storage Unit 108 Address Information Management Unit 109 Path Table Management Unit 200 Packet Transfer Unit 201 Packet Transfer Rule Storage Unit 202 Packet Transfer rule management unit 203 Flow identification unit 204 Action execution unit 300 Transfer control unit 301 Use interface information storage unit 302 Use interface information management unit 303 Address information storage unit 304 Address information management unit 305 Route table management unit 306 Packet transfer rule generation unit 307 Packet transfer unit management unit 400 Connection monitoring unit

Claims (7)

A communication device that uses a network control method in units of flows, capable of selecting a network to be used for communication for each flow,
One or more communication interfaces;
A virtual interface;
A communication stack having one or more routing tables;
A packet transfer unit for transferring received packets;
A transfer control unit for controlling the operation of the packet transfer unit;
A connection monitoring unit that monitors connection between the packet transfer unit and the transfer control unit;
A communication apparatus comprising: The one or more routing tables are:
A first routing table used to enable communication by packet transfer by the packet transfer unit and the transfer control unit;
A second routing table used when the packet transfer cannot be performed;
The communication apparatus according to claim 1, further comprising: The transfer control unit
An address storage unit that stores information necessary for the one or more communication interfaces and the virtual interface to transmit and receive packets, and stores address information set in the one or more communication interfaces and the virtual interface; ,
An address information management unit that acquires the address information and stores the address information in the address storage unit; a routing table management unit that sets the first routing table based on information stored in the address information management unit;
With
The communication apparatus according to claim 1, wherein the first routing table is set so that the communication stack performs route control using route information related to a virtual default gateway set in the virtual interface. The communication stack is
An address storage unit for storing the address information;
An address information management unit for acquiring the address information and storing the address information in the address storage unit;
A routing table management unit configured to set the second routing table based on information stored in the address information management unit;
With
Setting the second route table so that the communication stack performs route control using route information regarding any one of the default gateways set for each of the one or more communication interfaces. The communication apparatus according to claim 1, wherein:   The connection monitoring unit switches a route table used for route control of the communication stack to the first route table or the second route table based on a connection state between the packet transfer unit and the transfer control unit. The communication apparatus according to claim 1, wherein communication is possible. One or more communication interfaces, a virtual interface, a communication stack having one or more routing tables, a packet transfer unit that transfers received packets, and a transfer control unit that controls the operation of the packet transfer unit A transfer control method for monitoring a connection between the packet transfer unit and the transfer control unit in a communication device that uses a network control method in units of flows, capable of selecting a network to be used for communication for each flow. ,
A transfer control method comprising: enabling communication by switching a route table used for route control of the communication stack based on a connection state between the packet transfer unit and the transfer control unit. One or more communication interfaces, a virtual interface, a communication stack having one or more routing tables, a packet transfer unit that transfers received packets, and a transfer control unit that controls the operation of the packet transfer unit A program that monitors a connection between the packet transfer unit and the transfer control unit in a computer that uses a network control method in units of flows that can select a network to be used for communication for each flow,
A transfer control program that enables communication by switching a route table used for route control of the communication stack based on a connection state between the packet transfer unit and the transfer control unit.

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