JP2013115733A - Network system and network control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a processing load required for message exchange between a network control device and a node device.SOLUTION: In a network system including the network control device and the node device for establishing a data communication path on receipt of an instruction from the network control device, the network control device transmits a network control instruction message to the node device only to a node device at an end point of an instruction target, without exchanging the network control instruction message between with all node devices of instruction targets from the network control device. On receipt of the network control instruction message, the node device relays the network control instruction message to adjacent nodes, to establish the data communication path.

Description

  The present invention relates to a network system, and more particularly to a method for controlling a network system.

[Description of CU separation type network system]
As one conventional network system control method, a network control device (control plane) that manages network control and a node device (user plane) that actually transfers data are physically separated. There has been proposed a CU (C: control plane / U: user plane) separation type network system that realizes network control by exchanging control instructions between node nodes.

  As an example of the CU separation type network system, there is an open flow network system using an open flow (OpenFlow) technology for controlling a switch from a controller and performing path control of the network system. The details of the open flow technique are described in Non-Patent Document 1. The OpenFlow network system is only an example.

[Explanation of OpenFlow network system]
In the OpenFlow network system, a controller such as OFC (OpenFlow Controller) controls the behavior of the switch by operating a flow table of the switch such as OFS (OpenFlow Switch). The controller and the switch are connected by a secure channel (Secure Channel) for the controller to control the switch using a control message conforming to the OpenFlow protocol.

  The switches in the OpenFlow network system are edge switches and core switches that form an OpenFlow network and are managed by the controller. A series of packet flows from reception of a packet at the input side edge switch to transmission at the output side edge switch in the OpenFlow network is called a flow.

  The packet may be read as a frame. The difference between a packet and a frame is only a difference in data units (PDU: Protocol Data Unit) handled by the protocol. The packet is a PDU of “TCP / IP” (Transmission Control Protocol / Internet Protocol). On the other hand, the frame is a PDU of “Ethernet” (registered trademark).

  The flow table is a table in which a flow entry (Flow entry) defining a predetermined operation (action) to be performed on a packet (communication data) that meets a predetermined matching condition (rule) is registered.

  The rule of the flow entry is any one of a destination address (Destination Address), a source address (Source Address), a destination port (Destination Port), a source port (Source Port) included in the header area of each protocol layer of the packet, or Defined and distinguishable by various combinations using all. Note that the above addresses include a MAC address (Media Access Control Address) and an IP address (Internet Protocol Address). In addition to the above, information on the ingress port (Ingress Port) can also be used as a rule for the flow entry. In addition, as a rule of the flow entry, a part (or all) of the header area value of the packet indicating the flow can be set by a regular expression, a wild card “*”, or the like.

  The action of the flow entry indicates operations such as “output to a specific port”, “discard”, and “rewrite header”. For example, if the identification information (output port number, etc.) of the output port is indicated in the action of the flow entry, the switch outputs a packet to the corresponding port, and if the identification information of the output port is not indicated , Discard the packet. Alternatively, if the header information is indicated in the action of the flow entry, the switch rewrites the header of the packet based on the header information.

  The switch in the OpenFlow network system executes a flow entry action on a packet group (packet sequence) that conforms to the rules of the flow entry.

  In other words, in the OpenFlow network system, the data communication path from the end point to the end point is handled as a flow path, and the controller sets the flow entry that becomes the data relay operation policy for the switch, thereby performing path control in units of flow paths. .

  As described above, in a network system formed by a data communication node device that establishes a data communication path in response to an instruction from the network control device, data is exchanged by exchanging network control instruction messages between the network control device and the node device. Establish a communication path.

  Also, in such a network system, in order to establish a data communication path, as shown in FIG. 1, a network control instruction message is sent to all of the node apparatuses that need to establish a path under the management of the network control apparatus. Need to send.

  Furthermore, when the network control device needs to know whether or not a route has been established, it is necessary to respond from each node device with a response message corresponding to the network control instruction message.

  For this reason, the network control device frequently exchanges network control instruction messages with respect to each node device, and the processing load on the network control device increases.

  Further, when expanding the network, as shown in FIG. 2, the number of node devices managed by a single network control device increases. Overheads of “network control instruction message transmission process” and “response reception process from node device” increase.

  Further, in order to reduce the load of the network control device related to the exchange of the network control instruction message, “limit the number of managed node devices”, “increase the hardware processing performance of the network control device”, or “ There is a method of implementing a countermeasure of “preparing a plurality of network control devices and distributing the load”.

  All of these measures require a great deal of cost for expanding the network control device when it is desired to expand the network system.

"OpenFlow Switch Specification, Version 1.0.0", [online], December 31, 2009, Internet (URL: http://www.openflowswitch.org/documents/openflow-spec.1).

  In a network system that performs network control by exchanging network control instruction messages between a network control device and a node device that actually performs data communication, the node device managed by the network control device by network expansion or the like When the number of network controllers increases, the number of times the network control instruction message is transmitted from the network control apparatus to the node device to be managed is increased accordingly, so that the CPU processing of the network control apparatus when the network control apparatus instructs network control The load and the message transmission load on the communication path for transmitting the network control instruction to each node device increase.

  Such a network control configuration has a problem that it is difficult to expand the network because the processing load increases each time the number of node devices managed by the network control device increases.

  An object of the present invention is to provide a network system that reduces the CPU processing load of the network control device and the compression of the bandwidth of the communication path between the network control device and the node device by transmitting a network control instruction message to each node device. That is.

  A network system according to the present invention forms a network and performs processing of received packets according to a flow entry in which rules and actions for uniformly controlling packets as flows are defined. And a network control device that changes the setting of the flow entry. The network control device determines a data communication path in the network and transmits a control message to one of the node devices on the data communication path. The node device on the data communication path relays a control message to the adjacent node device.

  The node device according to the present invention forms a network and processes a received packet according to a flow entry in which rules and actions for uniformly controlling packets as a flow are defined. Means for receiving the control message and changing the setting of the flow entry, and means for relaying the control message to the adjacent node device.

  In the network control method according to the present invention, a node device forms a network and processes received packets according to a flow entry in which rules and actions for uniformly controlling packets as flows are defined. Further, the network control device determines a data communication path in the network, and transmits a control message for changing the setting of the flow entry to one of the node devices on the data communication path. Further, the node device on the data communication path changes the setting of the flow entry based on the control message, and relays the control message to the adjacent node device.

  The program according to the present invention includes a step of processing a received packet in accordance with a flow entry in which rules and actions for forming a network and uniformly controlling packets as a flow are defined, and a control from the network control device A program for causing a node device to execute a step of receiving a message and changing a setting of a flow entry and a step of relaying a control message to an adjacent node device. The program according to the present invention can be stored in a storage device or a storage medium.

  It is possible to reduce the CPU processing load of the network control apparatus due to the network control apparatus transmitting a network control instruction message to all the node apparatuses.

It is a figure for demonstrating the example in which the network control apparatus performs the transmission / reception process of a control message between all the node apparatuses under management in the conventional system. It is a figure for demonstrating the example which the load of a network control apparatus increases by the part which the node apparatus under management of a network control apparatus increased in the conventional system. 1 is a diagram illustrating a basic configuration of a network system according to the present invention. It is a figure for demonstrating the example of the network structure in this invention. It is a figure for demonstrating the relay procedure of a route establishment instruction | indication. It is a figure for demonstrating the network structure in the Example of this invention. It is a figure for demonstrating transmission of a route registration instruction | indication message. It is a figure for demonstrating the relay procedure in an Example. It is a figure for demonstrating simultaneous notification of network configuration information. It is a figure for demonstrating the detection of the connection structure between node apparatuses. It is a figure for demonstrating the opportunity which performs flow entry registration. It is a figure for demonstrating the change of a data communication path | route. It is a figure for demonstrating deletion of a data communication path | route. It is a figure for demonstrating deletion of the path | route at the time of completion | finish of use of a data communication path | route.

  The present invention is directed to a CU separation type network system. Here, an OpenFlow network system, which is one of CU separation type network systems, will be described as an example. However, actually, it is not limited to the open flow network system.

<First Embodiment>
Hereinafter, a first embodiment of the present invention will be described with reference to the accompanying drawings.

  As shown in FIG. 3, the network system according to the present invention includes a network control device 10 and a node device 20 (20-i, i = 1 to n: n is arbitrary).

  The network control device 10 transmits and receives a network control instruction message to and from each of the node devices 20 (20-i, i = 1 to n).

  Each of the node devices 20 (20-i, i = 1 to n) relays (transfers) a network control instruction message from the network control device 10 to an adjacent node device (hereinafter referred to as an adjacent node device). Thus, a data communication path can be generated.

  Each of the node devices 20 (20-i, i = 1 to n) transmits a response to the network control instruction message to the network control device 10 when the generation of the communication path is completed. For example, each of the node devices 20 (20-i, i = 1 to n) determines that the generation of the communication path has been completed when there is no adjacent node device as the transfer destination, and returns a response to the network control instruction message. It transmits to the network control device 10.

[Configuration of network control unit]
Next, details of the configuration of the network control device 10 will be described.

  The network control device 10 includes a control instruction transmission / reception unit 11 and a route management unit 12.

  The control instruction transmission / reception unit 11 transmits / receives a network control instruction message to / from the node device 20 (20-i, i = 1 to n).

  The route management unit 12 manages a communication route on the network.

[Node device configuration]
Next, details of each configuration of the node device 20 (20-i, i = 1 to n) will be described.

  Each of the node devices 20 (20-i, i = 1 to n) includes a control instruction processing unit 21, a flow management unit 22, and a route existence monitoring unit 23.

  When receiving the network control instruction message from the network control device 10, the control instruction processing unit 21 checks whether there is an adjacent node device that has not yet received the network control instruction message. When there is a corresponding adjacent node device, the network control instruction message from the network control device 10 is relayed to the adjacent node device. When there is no corresponding adjacent node device, the control instruction is terminated and a response is transmitted to the network control device 10.

  Based on the network control instruction message, the flow management unit 22 registers and manages a flow entry serving as a data relay operation policy in the flow table. Further, the flow management unit 22 deletes the flow entry related to the data communication path from the flow table when the use of the data communication path is finished.

  The path existence monitoring unit 23 monitors data communication (data communication path usage status), and detects the end of use of the data communication path when the use of the data communication path ends.

[Basic configuration]
Next, an example of the basic configuration of the network system according to the present invention will be described.

  FIG. 3 illustrates the network control device 10, the node device 20-1, the node device 20-2, and the node device 20-n.

  The node device 20-1 is a node device at the starting point of the data communication path, and is a node device that receives and analyzes a network control instruction message from the network control device 10.

  The node device 20-2 is a node device in the middle of the data communication path, and is a node device that relays the network control instruction message from the network control device 10 to the adjacent node device.

  The node device 20-n is a node device at the end point of the data communication path, and is a node device that transmits a response to the network control instruction message to the network control device 10.

[Hardware example]
Hereinafter, specific examples of hardware for realizing the network system according to the present invention will be described.

  As an example of the network control apparatus 10, a computer such as a PC (personal computer), an appliance, a thin client server, a workstation, a mainframe, and a supercomputer is assumed. The network control device 10 is not limited to a terminal or a server, but may be a relay device or a peripheral device. The network control device 10 may be an expansion board mounted on a computer or the like, or a virtual machine (VM) constructed on a physical machine.

  Examples of the node device 20 (20-i, i = 1 to n) include a network switch, a router, a proxy, a gateway, a firewall, and a load balancer. : Load balancing device), bandwidth control device (packet shaper), security supervisory control device (SCADA: Supervision Control And Data Acquisition), gatekeeper (gatekeeper), base station (base station), access point (AP: access P) Communication satellite (CS) or multiple communication ports Computer and the like can be considered. Further, a virtual switch realized by a virtual machine (VM) constructed on a physical machine may be used.

  The network control device 10 and the node device 20 (20-i, i = 1 to n) include a processor that is driven based on a program and executes predetermined processing, a memory that stores the program and various data, and a network. This is realized by an interface used for communication.

  Examples of the processor include a CPU (Central Processing Unit), a network processor (NP), a microprocessor, a microcontroller (microcontroller), or a semiconductor integrated circuit (LSI: Large Scale) having a dedicated function. Integration) or the like.

  Examples of the memory include semiconductor storage devices such as a RAM (Random Access Memory), a ROM (Read Only Memory), an EEPROM (Electrically Erasable and Programmable Read Only Memory), a flash memory, and an HDD (Hold SMD). An auxiliary storage device such as State Drive), a removable disk such as a DVD (Digital Versatile Disk), a storage medium such as an SD memory card (Secure Digital memory card), or the like is conceivable. Further, a buffer, a register, or the like may be used. Alternatively, DAS (Direct Attached Storage), FC-SAN (Fibre Channel-Storage Area Network), NAS (Network Attached Storage), IP-SAN (IP-Storage Area), etc. may be used.

  Note that the processor and the memory may be integrated. For example, in recent years, a single chip such as a microcomputer has been developed. Therefore, a case where a one-chip microcomputer mounted on an electronic device or the like includes the processor and the memory can be considered.

  Examples of the interfaces include semiconductor integrated circuits such as substrates (motherboards and I / O boards) and chips that support network communication, network adapters such as NIC (Network Interface Card), and similar expansion cards and communication devices such as antennas. A communication port such as a connection port (connector) is conceivable.

  Examples of the network include the Internet, a LAN (Local Area Network), a wireless LAN (Wireless LAN), a WAN (Wide Area Network), a backbone (Backbone), a cable television (CATV) line, a fixed telephone network, a mobile phone network, WiMAX (IEEE 802.16a), 3G (3rd Generation), dedicated line (lease line), IrDA (Infrared Data Association), Bluetooth (registered trademark), serial communication line, data bus, and the like can be considered.

  The internal components of the network control device 10 and the node device 20 (20-i, i = 1 to n) are modules, components, dedicated devices, or their activation (calling) programs. But it ’s okay.

  However, actually, it is not limited to these examples.

[Network configuration]
A configuration example of the network will be described with reference to FIG.

  The network control device 10 and each of the node devices 20 (20-i, i = 1 to n) are connected by a network control instruction message exchange connection.

  In addition, each of the node devices 20 (20-i, i = 1 to n) is connected by a message communication path for relaying a network control instruction message between adjacent node devices. The message communication path is a message communication path equivalent to the network control instruction message exchange connection. As a result, network control instruction messages can be exchanged between adjacent node devices.

  Here, the node devices 20-1 to 20-7 are shown as the node devices 20 (20-i, i = 1 to n), respectively. Among these, the node device 20-1 and the node device 20-5 correspond to edge switches. The node device 20-2, the node device 20-3, the node device 20-4, the node device 20-6, and the node device 20-7 correspond to core switches. Node devices corresponding to edge switches are connected to terminals and other networks. The node device can also serve as an edge switch and a core switch.

[Relay procedure for route establishment instruction]
With reference to FIG. 5, the relay procedure of a route establishment instruction will be described.

  For example, when a network control instruction message is transmitted from the network control apparatus 10 to the node apparatus 20-1 and a path establishment instruction from the node apparatus 20-1 to the node apparatus 20-5 is performed, The route can be specified in two ways.

  (1) Designate all node devices (node device 20-1, node device 20-2, node device 20-3, node device 20-5) to be routed.

  (2) Designate only the node devices (node device 20-1 and node device 20-5) that are sure to pass through, such as the node device at the end point.

  As in (1), when all the node devices that pass through are specified, the node device that has received the network control instruction message analyzes the network control instruction message and identifies the adjacent node device in the next stage on the route. Then, the network control instruction is sequentially relayed to the adjacent node device in the next stage.

  As in (2), when specifying only a node device that must be routed, the node device itself that has received the network control instruction message determines the adjacent node device to which the network control instruction message should be relayed next, and Network control instructions are sequentially relayed to adjacent node devices.

[Establish data communication path]
First, a procedure for establishing a data communication path will be described.

  Each of the node devices (node device 20-1, node device 20-2, node device 20-3, node device 20-5) on the route is a network control instruction message (data communication route registration) from the network control device 10. A data communication path from the end point (node device 20-1) to the end point (node device 20-5) is established while relaying the change / deletion instruction message) between adjacent node devices.

  In the flow management unit 22 of the node device (node device 20-1, node device 20-2, node device 20-3, node device 20-5) on the route, the control instruction processing unit 21 receives the network control instruction message. At this time, a flow entry to be a data relay operation policy is registered based on the network control instruction message.

  As a result, the network control device 10 determines what match conditions (rules) each of the node devices (node device 20-1, node device 20-2, node device 20-3, node device 20-5) on the route has. Arbitrary rules can be specified as to whether a packet matching the above is relayed.

  In addition, the network control device 10 responds to a packet in which each of the node devices (node device 20-1, node device 20-2, node device 20-3, node device 20-5) on the route matches an arbitrary rule. Any action can be specified as to what kind of operation (action) is performed.

  Furthermore, the network control device 10 individually applies rules and actions to each of the node devices (node device 20-1, node device 20-2, node device 20-3, node device 20-5) on the route. Can be specified.

[End use of data communication path]
Next, a procedure when the use of the data communication path is completed will be described.

  When the use of the data communication path ends, the path survival monitoring unit 23 of the node device (node device 20-1) at the start point of the data communication path detects that the use of the data communication path has ended.

  For example, when the control instruction processing unit 21 of the starting point node device (node device 20-1) receives a control instruction message from the network control device 10 indicating that the use of the data communication path has ended, the starting point node device ( The path existence monitoring unit 23 of the node device 20-1) detects that the use of the data communication path has ended.

  Alternatively, when the starting node device (node device 20-1) does not receive a packet corresponding to the flow for a certain period of time, the path existence monitoring unit 23 of the starting node device (node device 20-1) Detects the end of use of the communication path. In this case, the control instruction processing unit 21 of the starting node device (node device 20-1) generates a control instruction message indicating that the use of the data communication path has ended.

  Each control instruction processing unit 21 of the node device (node device 20-1, node device 20-2, node device 20-3, node device 20-5) on the route follows the same procedure as that for establishing the data communication route. The control instruction message is relayed between the node devices on the data communication path.

  Thereby, each of the node devices (node device 20-1, node device 20-2, node device 20-3, node device 20-5) on the route is related to the data communication route in the order in which the control instruction message is received. The flow entry is deleted from the flow table, and the use of the data communication path is ended.

  Finally, the control instruction processing unit 21 of the node device (node device 20-5) at the end of the data communication path notifies the network control device 10 of a message indicating that the flow entry related to the data communication path has been deleted. To do.

[Advantages of this embodiment]
Next, advantages of this embodiment will be described.

  With the above feature, the network control device always transmits a network control instruction message only to the node device at the end point (node device 20-1 etc. in FIG. 5), and the response is sent to the node device at the other end point (in FIG. 5). It is only necessary to receive from the node device 20-5 or the like. The load applied when the network control apparatus performs the “network control instruction message transmission process” and the “response reception process” hardly increases even when the path changes. For this reason, it is possible to reduce the processing load caused by the network control device exchanging route registration instruction messages with a plurality of node devices.

  Further, even when the number of node devices managed by the network control device is increased due to expansion of the network system or the like, the network control device always sends a network control instruction message to the end node device (node device 20-1 in FIG. 5). Etc.) and the response only needs to be received from the node device at the other end point (node device 20-5 in FIG. 5). The load applied when the network control device performs “network control instruction message transmission processing” and “response reception processing” hardly increases even when the number of node devices to be managed increases. For this reason, it is possible to easily perform scale out of the network system.

[Example]
The network configuration in the embodiment of the present invention will be described with reference to FIG.

  The network system according to the embodiment of the present invention includes a network control device 10, a node device 20 (20-i, i = 1 to n), and a terminal 30 (30-j, j = 1 to m: m are arbitrary). Is provided.

  The network control device 10 and the node device 20 (20-i, i = 1 to n) are the same as those shown in FIG. The terminal 30 (30-j, j = 1 to m) is a terminal outside the OpenFlow network.

  Here, description will be made using the network control device 10, the node devices 20-1 to 20-7, and the terminals 30-1 to 30-2.

  The network control device 10 manages the node devices 20-1 to 20-7. The node devices 20-1 to 20-7 form an open flow network. The node device 20-1 is connected to the terminal 30-1. The node device 20-5 is connected to the terminal 30-2.

  At this time, since the network control apparatus 10 establishes a data communication path from the terminal 30-2 to the terminal 30-1, an optimal path (shortest path) for data communication from the terminal 30-2 to the terminal 30-1 is set. decide. Thereafter, the network control device 10 transmits a route registration instruction message for registering an optimum route from the terminal 30-2 to the terminal 30-1 to the node device 20-1.

  The node device 20-1 receives the route registration instruction message from the network control device 10. The control instruction processing unit 21 of the node device 20-1 analyzes the instruction content of the received message. The flow management unit 22 of the node device 20-1 registers a flow entry serving as a data relay operation policy in the flow table in accordance with the instruction content of the message. The control instruction processing unit 21 of the node device 20-1 relays the route registration instruction message to the next node device 20-2 instructed from the network control device 10.

  The node device 20-2 receives the route registration instruction message from the adjacent node device 20-1. The control instruction processing unit 21 of the node device 20-2 analyzes the content of the route registration instruction message received from the node device 20-1. The flow management unit 22 of the node device 20-2 registers a flow entry serving as a data relay operation policy in the flow table in accordance with the instruction content of the message. The control instruction processing unit 21 of the node device 20-2 relays the route registration instruction message to the next node device 20-3.

  The node device 20-3 receives the route registration instruction message from the adjacent node device 20-2. The control instruction processing unit 21 of the node device 20-3 analyzes the content of the route registration instruction message received from the node device 20-2. The flow management unit 22 of the node device 20-3 registers a flow entry serving as a data relay operation policy in the flow table in accordance with the instruction content of the message. The control instruction processing unit 21 of the node device 20-3 relays the route registration instruction message to the next node device 20-5.

  The node device 20-5 is a node device at the final point of route registration. The control instruction processing unit 21 of the node device 20-5 analyzes the content of the route registration instruction message received from the node device 20-3. The flow management unit 22 of the node device 20-5 registers a flow entry serving as a data relay operation policy in the flow table in accordance with the instruction content of the message. The control instruction processing unit 21 of the node device 20-5 transmits a registration response message corresponding to the route registration instruction message to the network control device 10.

  After the data communication path is established, the terminal 30-1 and the terminal 30-2 transmit and receive packets via the connected node devices.

  Note that a terminal is not necessarily connected to the end of the node device 20-1 or the node device 20-5, but is connected to a network managed by another network control device or a network of another network control method. There can also be a configuration. That is, the terminal 30-1 and the terminal 30-2 are not necessarily terminals. For example, the terminal 30-1 and the terminal 30-2 may be node devices of other networks that are not under the management of the network control device 10.

[Send route registration instruction message]
With reference to FIG. 7, transmission of a route registration instruction message from the network control apparatus 10 will be described.

  For example, the path management unit 12 of the network control device 10 performs data communication through “node device 20-5” → “node device 20-4” → “node device 20-2” → “node device 20-1” in this order. The route is determined as the optimum route from the terminal 30-2 to the terminal 30-1.

  After the optimum route from the terminal 30-2 to the terminal 30-1 is determined, the control instruction transmission / reception unit 11 of the network control device 10 sends the route to the node device 20-1 on the most downstream side of the optimum route. A route registration instruction message for registering the flow entry for is transmitted.

  As a method for the network control device 10 to designate a node device to be routed, it is conceivable that some identification information is assigned to each node device and the identification information is designated.

  Here, during flow entry registration related to the data communication route to each node device on the route, an unintended operation when a packet that hits the rule of the flow flows in the flow entry registered node device (flow entry not yet entered). In order to prevent the relay of registration to adjacent node devices), the route is set from the most downstream to the upstream of the data transfer route. However, in practice, the setting may be started from any node device on the route.

[Relay procedure in the embodiment]
With reference to FIG. 8, the relay procedure in an Example is demonstrated.

  The node device 20-1 performs a flow relating to a communication path from the network control device 10 through “node device 20-5” → “node device 20-4” → “node device 20-2” → “node device 20-1”. A route registration instruction message for registering an entry is received.

  The node device 20-1 receives the route registration instruction message from the terminal 30-2 received from the node device 20-2 based on the content designated by the network control device 10 (the content of the route registration instruction message). The flow entry for relaying the data to the terminal 30-1 is registered. In addition, for a portion where there is no instruction from the network control device 10 (for example, an output port or a transfer destination), an appropriate flow entry is generated as long as the node device 20-1 does not violate the instruction from the network control device 10. It is also possible to register a flow entry.

  When the node device 20-1 registers the flow entry based on the route registration instruction message, the node device 20-1 relays the route registration instruction message to the node device 20-2. Note that the flow entry registration and the route registration instruction message relay may be processed in series (sequentially or sequentially) or in parallel (simultaneously).

  At this time, since all the node devices 20 (20-i, i = 1 to n) need to determine which node device to relay the route registration instruction message next, the identification information of the adjacent node devices It is necessary to know in advance.

[Broadcast notification of network configuration information]
Referring to FIG. 9, one of the methods for recognizing identification information of adjacent node devices 20 (20-i, i = 1 to n) by each node device 20 (20-i, i = 1 to n). Next, a method for simultaneously notifying network configuration information from the network control apparatus 10 will be described.

  Here, the path management unit 12 of the network control device 10 stores in advance network configuration information indicating the connection configuration of all the node devices 20 (20-i, i = 1 to n) managed by the network control device 10. It shall be.

  In practice, the path management unit 12 of the controller 20 performs topology (topology: network connection form) detection by LLDP (Link Layer Discovery Protocol) or the like, and node devices 20 (20-i, The network configuration information may be generated by detecting i = 1 to n). Thereby, the path management unit 12 of the controller 20 recognizes the identification information (node device ID, MAC address, etc.) of all the node devices constituting the network, and the connection form of each node device, and the next stage of each node device. It becomes possible to specify the node device.

  The control instruction transmission / reception unit 11 of the network control device 10 notifies the connection configuration of all the node devices 20 (20-i, i = 1 to n) managed by the network control device 10, so that the path management unit of the network control device 10 The network configuration information managed by 12 is transmitted to each node device 20 (20-i, i = 1 to n).

  Each node device 20 (20-i, i = 1 to n) receives the network configuration information from the network control device 10, and based on the network configuration information, all the node devices 20 (20-i, i = 1 to n). ) Is stored.

  Each node device 20 (20-i, i = 1 to n) is based on the connection configuration of all node devices 20 (20-i, i = 1 to n), and adjacent node device 20 (20-i, i = 1 to n) are identified.

[Detection of connection configuration between node devices]
Referring to FIG. 10, the node device 20 (20-i, i = 1 to n) is a method for recognizing the identification information of the adjacent node device 20 (20-i, i = 1 to n). First, a method for detecting a connection configuration between node devices will be described.

  Each node device 20 (20-i, i = 1 to n) exchanges connection information between adjacent node devices 20 (20-i, i = 1 to n), so that the network configuration from the network control device 10 No information is required, only the node device 20 (20-i, i = 1 to n) detects the connection configuration of each node device 20 (20-i, i = 1 to n), and the adjacent node device 20 ( 20-i, i = 1 to n) is identified.

[Sum of both information]
A method combining the methods shown in FIGS. 9 and 10 will be described.

  Each node device 20 (20-i, i = 1 to n) includes network configuration information from the network control device 10 and connection information from the adjacent node device 20 (20-i, i = 1 to n). Information obtained by adding both pieces of information is stored.

  Each node device 20 (20-i, i = 1 to n) grasps identification information of the adjacent node device 20 (20-i, i = 1 to n) based on the information obtained by adding both pieces of information.

[When to register a flow entry]
With reference to FIG. 11, a description will be given of an opportunity for each node device 20 (20-i, i = 1 to n) to perform flow entry registration.

  Each node device 20 (20-i, i = 1 to n) receives a route registration instruction message from the network control device 10 as “node device 20-1” → “node device 20-2” → “node device 20-4”. "→" node device 20-5 "is sequentially relayed to perform flow entry registration relating to a data communication path for relaying data from the terminal 30-2 to the terminal 30-2.

  Each node device 20 (20-i, i = 1 to n) registers a flow entry based on the content of the route registration instruction message when it receives the route registration instruction message from the network control device 10.

  At this time, each node device 20 (20-i, i = 1 to n) registers the flow entry in an invalid state, and all the node devices on the path (node device 20-1, node-equipped node device). 20-2, the node device 20-4, and the node device 20-5) after confirming that the registration of the flow entry has been completed, all the node devices (nodes) on the route according to the instruction from the network control device 10 The flow entry of the device 20-1, the node equipment node device 20-2, the node device 20-4, and the node device 20-5) may be validated.

  When the registration of the flow entries of all the node devices (node device 20-1, node-equipped node device 20-2, node device 20-4, and node device 20-5) on the route is completed, from the terminal 30-2 When the generation of the data communication path to the terminal 30-1 is completed and the subsequent data communication from the terminal 30-2 to the terminal 30-1, "node device 20-5" → "node device 20-4" → Relay via the route of “node device 20-2” → “node device 20-1”.

  When each node device 20 (20-i, i = 1 to n) succeeds in establishing the data communication path, each node device 20 (node device 20-1, node device 20-1) is connected to the established data communication path. A response message is transmitted to the network control device 10 regarding the flow entry information registered in the node device 20-2, the node device 20-4, and the node device 20-5).

  The path management unit 12 of the network control apparatus 10 receives the response message and manages the established data communication path.

[Description of effects]
In the present embodiment, when the network control device sends a route registration instruction message to the managed node device, the network control device does not individually send the route registration instruction message to all the node devices that should send the instruction message. The route registration instruction message is transmitted only to the representative node device. Each node device can perform processing on the route registration instruction message while relaying the route registration instruction message between the node devices. For this reason, it is possible to reduce the CPU processing load of the network control device due to the network control device transmitting an instruction message to all the node devices.

  For the instruction exchange connection between the network control device and each node device, the network control device transmits a route registration instruction message only to the representative node device. Each node device can perform processing for an instruction from the network control device while relaying a route registration instruction message between the node devices. For this reason, the data transfer amount of the instruction exchange connection of other node devices can be reduced.

  Further, when expanding the scale of the network, even if one network control device needs to manage a large number of node devices, the network control device transmits a route registration instruction message only to the representative node device. Each node device can perform processing for the instruction while relaying a route registration instruction message between the node devices. For this reason, the transmission processing load of the network control instruction message related to the exchange of the control message between the node devices managed by the network control device hardly increases. Therefore, it is possible to easily scale out the number of node devices.

Second Embodiment
The second embodiment of the present invention will be described below.

  Also in the second embodiment of the present invention, the network configuration, the network control device, and the node device are basically the same as those in the first embodiment.

  In the first embodiment, the case where the data communication path from the terminal 30-2 to the terminal 30-1 is established by an instruction from the network control apparatus 10 has been described. However, in the present embodiment, an instruction from the network control apparatus 10 is used. A case where the data communication path is changed will be described.

[Change data communication path]
A case where the data communication path is changed will be described with reference to FIG.

  For example, the data communication path from the terminal 30-2 to the terminal 30-1 is “node device 20-5” → “node device 20-4” → “node device 20-2” → “node device 20-1”. It is assumed that the route is changed from “node device 20-5” → “node device 20-3” → “node device 20-2” → “node device 20-1”.

  At this time, the network control device 10 transmits a route change instruction message for changing the data communication route from the terminal 30-2 to the terminal 30-1 to the node device 20-1 at the end point.

  The node device 20-1 receives the route change instruction message, analyzes the contents, and as a result of the analysis, there is no change in the flow entry for relaying the packet from the node device 20-2 to the terminal 30-1, Since there is no need to change the flow entry, the route change instruction message is relayed to the node device 20-2.

  The node device 20-2 receives the path change instruction message, analyzes the contents, and based on the result of the analysis, a new flow for relaying the packet from the node device 20-3 to the node device 20-1. Register the entry in the flow table. At this time, the node device 20-2 may delete the flow entry related to the old route from the flow table. Alternatively, instead of registering a new flow entry, the action of the flow entry relating to the old route may be changed to “operation for relaying a packet from the node device 20-3 to the node device 20-1.” Thereafter, the node device 20-2 relays a route change instruction message to the node device 20-3. The node device 20-2 may relay the route change instruction message to the node device 20-4 that needs to delete the flow entry related to the old route.

  The node device 20-3 receives the route change instruction message, analyzes the contents, and based on the result of the analysis, a new flow for relaying the packet from the node device 20-5 to the node device 20-2 Register the entry in the flow table. Thereafter, the node device 20-3 relays a route change instruction message to the node device 20-5.

  The node device 20-5 receives the route change instruction message, analyzes the contents, and based on the result of the analysis, a new flow entry for relaying the packet from the terminal 30-2 to the node device 20-3 Is registered in the flow table. At this time, the node device 20-5 may delete the flow entry related to the old route from the flow table. Alternatively, instead of registering a new flow entry, the action of the flow entry relating to the old route may be changed to “operation for relaying a packet from the terminal 30-2 to the node device 20-3”.

  At this point, since the change of the data communication path from the terminal 30-2 to the terminal 30-1 is completed, the node device 20-5 sends a change response message corresponding to the route change instruction message to the network control device 10. Send.

  Since the node device 20-5 needs to delete the flow entry related to the old route when the data communication route is changed, the node device 20-5 relays the route change instruction message to the node device 20-4.

  The node device 20-4 receives the route change instruction message, analyzes the content, and deletes the flow entry related to the old route based on the analysis result. Further, the node device 20-4 relays a route change instruction to the node device 20-2 that needs to delete the flow entry related to the old route.

  The node device 20-2 receives the route change instruction message, analyzes the contents, and deletes the flow entry related to the old route when the flow entry related to the old route is still registered in the flow table. Further, the node device 20-2 discards the route change instruction message because there is no other node device that needs to delete the flow entry related to the old route.

  In practice, not the node device 20-5 but the node device 20-2 that has received the route change instruction message last may transmit the change response message to the network control device 10.

  In addition to the change of the data communication path, the path can be deleted separately by an instruction from the network control apparatus 10.

[Delete data communication path]
With reference to FIG. 13, a case where a route is deleted by an instruction from the network control device 10 will be described.

  For example, the flow entry related to the data communication path of “node device 20-5” → “node device 20-4” → “node device 20-2” → “node device 20-1” is deleted from the flow table of each node device. Shall.

  At this time, the network control device 10 transmits a route deletion instruction message for deleting the old data communication route from the terminal 30-2 to the terminal 30-1 to the node device 20-1 at the end point.

  The node device 20-1 receives the route deletion instruction message, analyzes the contents, and based on the result of the analysis, an old flow entry for relaying the packet from the node device 20-2 to the terminal 30-1. Delete from the flow table. Thereafter, the node device 20-1 relays a route deletion instruction message to the node device 20-2.

  The node device 20-2 receives the route deletion instruction message, analyzes the contents, and based on the result of the analysis, the old flow entry for relaying the packet from the node device 20-4 to the node device 20-1 Is deleted from the flow table. Thereafter, the node device 20-2 relays a route deletion instruction message to the node device 20-4.

  The node device 20-4 receives the route deletion instruction message, analyzes the contents, and based on the result of the analysis, the old flow entry for relaying the packet from the node device 20-5 to the node device 20-2 Is deleted from the flow table. Thereafter, the node device 20-4 relays a route deletion instruction message to the node device 20-5.

  The node device 20-5 receives the route deletion instruction message, analyzes the contents, and based on the result of the analysis, an old flow entry for relaying the packet from the terminal 30-2 to the node device 20-4. Delete from the flow table.

  At this point, since the deletion of the old data communication path from the terminal 30-2 to the terminal 30-1 is completed, the node apparatus 20-5 sends a deletion response to the network control apparatus 10 in response to the path deletion instruction message. Send a message.

[Delete the route when the data communication route ends]
Referring to FIG. 14, a case will be described in which a flow entry related to a data communication path is deleted from the flow table when use of the data communication path ends without depending on an instruction from the network control device 10.

  For example, a flow entry relating to a data communication path of “node device 20-5” → “node device 20-4” → “node device 20-2” → “node device 20-1” is registered in the flow table of each node device. It shall be.

  At this time, when the end node device 20-1 detects the completion of the data communication between the terminal 30-2 and the terminal 30-1, the node device 20-1 generates a route deletion instruction message. A route deletion instruction message for deleting an old data communication route from 30-2 to the terminal 30-1 is relayed. For example, the path existence monitoring unit 23 of the node device 20-1 monitors data communication between the terminal 30-2 and the terminal 30-1, and the data between the terminal 30-2 and the terminal 30-1 for a certain period of time. When there is no communication, the flow management unit 22 of the node device 20-1 is notified. The flow management unit 22 of the node device 20-1 deletes the old flow entry for relaying the packet from the node device 20-2 to the terminal 30-1 from the flow table. Thereafter, the control instruction processing unit 21 of the node device 20-1 generates a route deletion instruction message for deleting an old data communication route from the terminal 30-2 to the terminal 30-1, and the adjacent node device 20-2. In response to this, the route deletion instruction message is relayed.

  The node device 20-2 receives the route deletion instruction message, analyzes the contents, and based on the result of the analysis, the old flow entry for relaying the packet from the node device 20-4 to the node device 20-1 Is deleted from the flow table. Thereafter, the node device 20-2 relays a route deletion instruction message to the node device 20-4.

  The node device 20-4 receives the route deletion instruction message, analyzes the contents, and based on the result of the analysis, the old flow entry for relaying the packet from the node device 20-5 to the node device 20-2 Is deleted from the flow table. Thereafter, the node device 20-4 relays a route deletion instruction message to the node device 20-5.

  The node device 20-5 receives the route deletion instruction message, analyzes the contents, and based on the result of the analysis, an old flow entry for relaying the packet from the terminal 30-2 to the node device 20-4. Delete from the flow table.

  At this point, since the deletion of the old data communication path from the terminal 30-2 to the terminal 30-1 is completed, the node apparatus 20-5 sends a deletion response to the network control apparatus 10 in response to the path deletion instruction message. Send a message.

  Thereby, the network control device 10 grasps that the old data communication path has been deleted in each node device.

<Relationship between each embodiment>
Note that the above embodiments can be implemented in combination.

<Features of the present invention>
In the present invention, when setting the route, the route is set while relaying an instruction from the network control device between the node devices on the route.

  In the present invention, in a network system including a network control device and a node device that actually relays communication data in response to a network control instruction message from the network control device, the network control message between the network control device and the node device Reduce the number of exchanges. Thereby, the CPU processing load of the network control device and the compression of the bandwidth of the communication path between the network control device and the node device due to the transmission of the network control instruction message to each node device are reduced. Further, the present invention provides a network system in which the load on the network control device is hardly increased even when the network is expanded.

  The network system according to the present invention includes a network control device and a node device that establishes a data communication path in response to an instruction from the network control device. The network control device does not exchange the network control instruction message to the node device with all the target node devices from the network control device, but transmits the network control instruction message only to the node device at the target end point. To do. When the node device receives the network control instruction message, the node device relays the network control instruction message to an adjacent node to establish a data communication path. This reduces the processing load associated with message exchange between the network control device and the node device.

  In the present invention, the network control instruction message from the network control device is relayed between the data relay devices by using the control connection for exchanging the route registration message between the network control device and the node device also between the node devices. I was able to do it.

  Further, a data communication path is established while relaying a path registration instruction message from the network control apparatus between the node apparatuses, and a path registration response message is transmitted to the network control apparatus from the node apparatus that finally received the message.

  Further, the data communication path is changed while relaying the path change instruction message from the network control apparatus between the node apparatuses, and the path change response message is transmitted from the node apparatus that has received the message to the network control apparatus.

  Further, the data communication path is deleted while relaying a path deletion instruction message from the network control apparatus between the node apparatuses, and a path deletion response message is transmitted to the network control apparatus from the node apparatus that finally received the message.

  Each node device has a function of receiving a network control instruction message from the network control device and analyzing the network control instruction message.

  Each node device has a function of relaying a network control instruction message from the network control device to another node device.

  Each node device terminates the network control instruction message from the network control device and transmits a response to the instruction source network control device.

<Remarks>
As mentioned above, although embodiment of this invention was explained in full detail, actually, it is not restricted to said embodiment, Even if there is a change of the range which does not deviate from the summary of this invention, it is included in this invention.

DESCRIPTION OF SYMBOLS 10 ... Network control apparatus 11 ... Control instruction transmission / reception part 12 ... Path | route management part 20 ... Node apparatus 21 ... Control instruction | indication processing part 22 ... Flow management part 23 ... Path | route survival monitoring part 30 ... Terminal

Claims (9)

A node device that processes a received packet in accordance with a flow entry in which rules and actions for forming a network and uniformly controlling packets as a flow are defined;
A network control device that transmits a control message to the node device and changes the setting of the flow entry,
The network control device determines a data communication path in the network, transmits the control message to one of the node devices on the data communication path;
A node system on the data communication path relays the control message to an adjacent node device. The network system according to claim 1,
The network control device transmits the control message to a node device at the end point of the data communication path, receives a response message corresponding to the control message from the node device at the start point of the data communication path,
A node system on the data communication path relays the control message from an end point of the data communication path to a start point. The network system according to claim 1 or 2,
The node device at the end of the data communication route relays the route change instruction message to the node device on the route before the change when the control message is a route change instruction message instructing a route change.
The node system on the route before change receives the route change instruction message, and deletes a flow entry related to the route before change. The network system according to any one of claims 1 to 3,
The node device at the end of the data communication path monitors the presence or absence of data communication on the data communication path, and deletes the flow entry related to the data communication path when there is no data communication on the data communication path for a certain period of time. , Generating a route deletion instruction message for deleting the flow entry relating to the data communication route, relaying the route deletion instruction message to the adjacent node device,
When the other node device on the data communication path receives the route deletion instruction message, it deletes the flow entry related to the data communication path and relays the route deletion instruction message to the adjacent node device. system. Means for processing a received packet in accordance with a flow entry in which rules and actions for forming a network and uniformly controlling a packet as a flow are defined;
Means for receiving a control message from a network control device and changing the setting of the flow entry;
A node device comprising means for relaying the control message to an adjacent node device. The node device according to claim 5, wherein
Means for analyzing the control message and determining the presence or absence of an adjacent node device on the data communication path based on the analysis result;
Means for relaying the control message to an adjacent node device when there is an adjacent node device;
A node device further comprising means for transmitting a response message corresponding to the control message to the network control device when there is no adjacent node device. The node device according to claim 5 or 6, wherein
Means for monitoring the presence or absence of data communication on the data communication path, if the end point of the data communication path;
Means for deleting a flow entry related to the data communication path when there is no data communication on the data communication path for a certain period of time;
Means for generating a route deletion instruction message for deleting a flow entry relating to the data communication route, and relaying the route deletion instruction message to an adjacent node device;
A node device further comprising means for deleting a flow entry related to the data communication path when the path deletion instruction message is received. A node device forms a network, processes a received packet according to a flow entry in which rules and actions for uniformly controlling the packet as a flow are defined;
A network control device determining a data communication path in the network and transmitting a control message for changing the setting of the flow entry to one of the node devices on the data communication path;
A network control method comprising: a node device on the data communication path changing a setting of the flow entry based on the control message and relaying the control message to an adjacent node device. Processing a received packet according to a flow entry in which rules and actions for forming a network and uniformly controlling a packet as a flow are defined;
Receiving a control message from a network control device and changing the setting of the flow entry;
A program for causing a node device to execute a step of relaying the control message to an adjacent node device.

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