JP5413737B2 - Network system and route information update method - Google Patents

Description

  The present invention relates to a network system, and more particularly to a network system in which an external controller controls network devices.

  A conventional network (NW) device is a black box, and cannot perform flexible control such as load distribution or offset from the outside. For this reason, when the scale of the network increases, it becomes difficult to grasp and improve the behavior of the system, and there has been a problem that a great deal of delay is involved in design and configuration change.

  As a technique for solving such a problem, a technique of separating packet transfer and routing control functions of a network (NW) device is considered. For example, a network (NW) device is in charge of packet transfer, and a controller placed outside the network (NW) device is in charge of path control. It becomes possible to build.

  As a specific example of the above method, open flow (OpenFlow) will be described. However, OpenFlow is only an example. About open flow, examination is progressing in the open flow consortium (refer nonpatent literature 1).

  FIG. 1 shows a basic configuration example of OpenFlow 0.9.0. In FIG. 1, a switch is shown as an example of a network (NW) device. FIG. 2 shows a conventional packet processing flow in the case of OpenFlow, which is a standard for a network (NW) device in which packet transfer and path control are separated. FIG. 3 shows a flow of conventional packet matching processing.

  OpenFlow is composed of a network (NW) device that supports the OpenFlow protocol and an external controller. The network (NW) device and the controller are connected by a secure channel (Secure channel) and communicate by the open flow protocol. In OpenFlow, packet transfer and route control of a network (NW) device are separated, the network (NW) device performs packet transfer, and the controller performs route control of the network (NW) device.

  A network (NW) device that supports OpenFlow has route information called a flow table inside. The flow table is a table for managing a correspondence relationship between header area information (Header Field) of a packet defined as a flow (Flow) and processing (Action) when the packet arrives. Here, a set of header area information (Header Field) and processing (Action) is referred to as an entry. The header area information (Header Field) indicates a predetermined rule (Rule) that is a determination criterion of a packet depending on the content thereof. The processing (Action) includes forward processing for transferring a packet to a physical port or a virtual port, drop processing for discarding the packet, and the like, and is expressed by a bitmap (bitmap) or the like. The network (NW) device collates the header area information (Header Field) in the received packet with the header area information (Header Field) in the flow table. Action).

  With reference to FIG. 1, information that can be an element of header area information (Header Field) will be described.

  In FIG. 1, as information that can be elements of header area information (Header Field), “Ingress Port”, “Ether src”, “Ether dst”, “Ether type”, “VLAN ID”, “VLAN” “priority”, “IP src”, “IP dst”, “IP protocol”, “TCP / UDP src port”, and “TCP / UDP dst port” are shown. Any or all of these pieces of information are used when collating the flow table with the packet. That is, a flow is defined by combining any or all of these pieces of information.

  “Ingress Port” indicates an input port. “Ether src” indicates the MAC address (Media Access Control Address) of the transmission source (Source). “Ether dst” indicates the MAC address of the destination (Destination). “Ether type” indicates the type of the upper layer protocol. “VLAN ID” indicates identification information set for each port of a virtual LAN (Virtual Local Area Network) switch. “VLAN priority” indicates the priority of the corresponding port of the virtual LAN switch. “IP src” indicates a source IP address (Internet Protocol Address). “IP dst” indicates a destination IP address. “IP proto” indicates an IP protocol number. “TCP / UDP src port” indicates a port number of a transmission source in TCP (Transmission Control Protocol) or UDP (User Datagram Protocol). “TCP / UDP dst port” indicates a destination port number in TCP or UDP.

  The controller includes network (NW) device control means (switch control means in FIG. 1), updates the flow table of the network (NW) device via the secure channel, and sets the network (NW) device. Control.

  The network (NW) device is provided with a packet transfer means (packet processing means in FIG. 1). When a packet arrives, it collates the packet with an internal flow table, and if there is a corresponding entry, it is associated. Processing (Action) such as packet transmission and discarding is executed.

Here, the flow of conventional packet processing will be described with reference to FIG.
The network (NW) device receives a packet from the network (“Packet in from network” in FIG. 2).

  A plurality of network (NW) devices exist on the network, and each network (NW) device maintains a loop-free logical topology in accordance with STP (Spanning Tree Protocol) of the IEEE 802.1D standard. Each network (NW) device is branched like a tree from a network (NW) device serving as a root bridge. Each network (NW) device receives the packet and processes the packet (“802.1d STP Processing” in FIG. 2).

  The network (NW) device collates the received packet with the entry of the internal flow table (“Flow lookup” in FIG. 2).

Here, a conventional packet matching process will be described in detail with reference to FIG.
First, the network (NW) device adds “Ingress Port” and “Ether src” to the header area information (Header Field) of the packet to be collated when collating with the header area information (Header Field) of the entry in the flow table. "Ether dst" and "Ether type" are specified ("Header Field = <Ingress Port, Ether src, Ether dst, Ether type>" in FIG. 3).

  The network (NW) device checks whether the value of “Ether type” in the header area information (Header Field) of the packet is “0x8100” (“Ether type = 0x8100?” In FIG. 3).

  When the value of “Ether type” is “0x8100”, the network (NW) device adds “VLAN ID” to the header area information (Header Field) as a new collation target. That is, the network (NW) device also sets “Ether type” as a verification target. At this time, the network (NW) device uses the value of the encapsulated “Ether type” as the value of “Ether type” (“Add <VLAN ID> to Header Field, Use encapsulated Ether type as shown in FIG. 3). Ether type ").

  The network (NW) device checks whether the value of “Ether type” in the header area information (Header Field) of the packet is “0x800” (“Ether type = 0x800?” In FIG. 3).

  When the value of “Ether type” is “0x800”, the network (NW) device uses “IP src”, “IP dst”, and “IP protocol” as new collation targets, and header area information (Header) Field). That is, the network (NW) device also checks “IP src”, “IP dst”, and “IP protocol” (“Add <IP src, IP dst, IP protocol> to Header Field” in FIG. 3). ").

  The network (NW) device confirms whether the value of “IP protocol” in the header field information (Header Field) of the packet is “6” or “17” (“IP protocol = 6 or 17?” In FIG. 3). .

  When the value of “IP proto” is “6” or “17”, the network (NW) device uses “TCP / UDP src port” and “TCP / UDP dst port” as new collation targets, It adds to area | region information (Header Field). That is, the network (NW) device also checks “TCP / UDP src port” and “TCP / UDP dst port” (“Add <TCP / UDP src port, TCP / UDP dst port>” in FIG. 3). to Header Field ").

  The network (NW) device collates the header area information (Header Field) of the entry in the flow table with the header area information (Header Field) of the packet (“Packet Lookup Over Header Field” in FIG. 3).

  When there is a corresponding entry in the flow table for the received packet, the network (NW) device executes processing (Action) such as packet transmission and discard associated with this entry ("" in FIG. 2). "Apply actions").

  In addition, when there is no corresponding entry in the flow table for the received packet, the network (NW) device holds this packet internally, and an unknown packet is sent to the controller via the secure channel (Secure channel). Is notified ("Send to secure channel" in FIG. 2). Here, an unknown packet when the corresponding entry does not exist is referred to as a 1st packet (First packet).

  Upon receiving the notification of arrival of the first packet, the controller calculates a route to the destination, adds a new entry to the flow table of the network (NW) device, and updates the flow table. The route to the destination is calculated from topology information (Network Topology) indicating which network (NW) device is connected to which network (NW) device.

  When the flow table is updated, the network (NW) device processes the staying 1st packet and the same type of subsequent packets according to the added processing (Action).

  Therefore, in a normal open flow, when a 1st packet arrives at a network (NW) device in which packet transfer and routing are separated, a notification from the network (NW) device to the controller and a flow from the controller to the network (NW) device Since table updating occurs, communication costs (burden) are incurred compared to conventional network (NW) devices.

  Furthermore, this cost is significant when considering a large-scale network such as a data center. In a large-scale network, from the viewpoint of performance and reliability, a plurality of controllers share and manage all network (NW) devices in the network. Topology information for route calculation is shared by all controllers.

  Hereinafter, the flow of processing in the conventional network system will be described in detail with reference to FIG. Here, a network (NW) device A, a network (NW) device B, a network (NW) device C, and a network (NW) device D are shown as network (NW) devices compatible with OpenFlow. In addition, a non-compatible network (NW) device is shown as a network (NW) device that does not support OpenFlow.

(1) 1st packet reception notification When receiving the 1st packet from the node, the network (NW) device A notifies the controller that controls the network (NW) device A that the 1st packet has been received.

(2) Network (NW) device C, network (NW) device D update instruction When the controller that controls the network (NW) device A receives a notification from the network (NW) device A, the route is determined based on the topology information. calculate. When the calculated path crosses the network (NW) device C and the network (NW) device D controlled by different controllers, the controller controlling the network (NW) device A The route information of the network (NW) device C and the network (NW) device D is notified, and the flow table of the network (NW) device C and the network (NW) device D is instructed to be updated.

(3) Network (NW) device C, network (NW) device D update The controller that controls the network (NW) device C adds a new entry to the flow table of the network (NW) device C and updates the flow table. . Similarly, the controller that controls the network (NW) device D adds a new entry to the flow table of the network (NW) device D and updates the flow table.

(4) Network (NW) device C and network (NW) device D update completion The controller that controls the network (NW) device A sends the network (NW) device C and network (NW) device from the controller that has notified the update instruction. The notification that the update of the flow table of D is completed is received.

(5) Network (NW) device A update, network (NW) device B update The controller that controls the network (NW) device A is connected to all network (NW) devices controlled by different controllers on the calculated path. When the update of the flow table is completed, a new entry is added to the flow table of the notification source network (NW) device A and the other subordinate network (NW) device B based on the calculated route, and the flow table is updated. . That is, the controller notifies the update instruction to all the controllers that control network (NW) devices that are not under its control on the calculated route, synchronizes by response, and the network (NW) device on the calculated route. After confirming that the update of the flow table is completed, the flow table of the network (NW) device under its control is updated.

  As shown in FIG. 4, when a route of a packet crosses a network (NW) device group controlled by different controllers, a flow table update instruction and a synchronization wait of the network (NW) device in the route are transmitted between the controllers. Occurs and packet transfer is delayed until it completes.

  Conversely, even if the flow table is not updated, if the flow table has not been updated when the packet arrives at the network (NW) device on the route, the packet is treated as a 1st packet. Cost.

  From the above, when reconfiguring an existing network with a network (NW) device that separates packet forwarding and routing, there is a high possibility that system performance will deteriorate. There is a possibility of disappearing.

  As a related technique, Japanese Patent Application Laid-Open No. 2004-320693 discloses a packet control system, a packet control device, a packet relay device, and a packet control program. In this related technology, the packet relay device transfers the route control packet received by the network interface to the packet control device. The packet control device receives the virtual interface that holds the address information associated with the network interface and the route control packet transferred from the packet relay device, forwards it to the route control process in association with the virtual interface, and performs route control. A route control packet transmitted by the process in association with the virtual interface is received and transferred to the packet relay device. In this way, the relay function and control function of the router are separated.

  Patent Document 2 (Japanese Patent Laid-Open No. 2007-096912) discloses a network repeater. In this related technology, it exchanges route information with other routers, updates the route information of its own router, and stops the packet relay processing in the router that performs the relay processing of the received packet based on the updated route information. Compress and update the route information of its own router without doing so. Accordingly, it is intended to cope with the increasing and expanding Internet route information without adding or updating router hardware.

JP 2004-320893 A JP 2007-096912 A

The OpenFlow Switch Consortium <http: // www. openflowswitch. org />

  In the present invention, in communication between network (NW) devices without communication between controllers, a packet to which a list of route information (flow table entries) is added is used for all network (NW) devices. We are also investigating a method for setting route information. This technique is very effective in a network in which all network (NW) devices are compatible with OpenFlow.

  However, in a network in which a network (NW) device compatible with OpenFlow and a non-compatible network (NW) device not compatible with OpenFlow are mixed, it is considered difficult to apply as it is for the following reason.

  The first reason is that a packet to which a list of route information is added is not a packet that conforms to a standard protocol, and thus may not be processed by a conventional non-compliant network (NW) device.

  The second reason is that there is a possibility that a fake route information transmitted from a network (NW) device that supports OpenFlow is added to a packet received from a network configured by a non-compatible network (NW) device. Therefore, it is a security problem to use for updating route information of network (NW) devices.

  In a large-scale network such as a data center, it is often introduced in stages, such as replacing existing equipment, rather than introducing all equipment newly. For this reason, even in a configuration in which network (NW) devices and non-compliant network (NW) devices coexist, a means for realizing setting of route information of the network (NW) devices at a low cost is required.

  The network system of the present invention includes a controller, a non-compliant network device that cannot be controlled by the controller, a network device in the previous stage of the non-compliant network device, and a network device in the subsequent stage of the non-compliant network device. The controller includes a means for controlling the network device in the previous stage, a means for calculating a route to the destination for the packet notified from the network device in the previous stage, and a non-corresponding network device on the calculated route. And means for notifying the subsequent network device of the route information of the subsequent network device. When the subsequent network device receives a packet from the non-compliant network device, it extracts its own route information from the subsequent route information, and adds a new entry to its own flow table based on the extracted route information; Means for adding the remaining path information of the subsequent stage to the packet, and means for transmitting the packet to which the remaining path information of the subsequent stage is added according to the entry added to the own flow table.

  The path information update method of the present invention is implemented in a network system including a controller, a non-compliant network device that cannot be controlled by the controller, a network device in the previous stage of the non-compliant network device, and a network device in the subsequent stage of the non-compliant network device. The In the route information update method of the present invention, the previous network device is controlled by the controller. The controller calculates a route to the destination for the packet notified from the preceding network device. In addition, when there is a non-compliant network device on the calculated route, the controller notifies the subsequent network device of the route information of the non-compliant network device. In addition, when a subsequent network device receives a packet from a non-supporting network device, it extracts its own route information from the subsequent route information and adds a new entry to its own flow table based on the extracted route information. . Further, the remaining path information in the subsequent stage is added to the packet by the network device in the subsequent stage. In addition, the subsequent network device transmits a packet to which the remaining path information of the subsequent stage is added according to the entry added to its own flow table.

  The program of the present invention is a program for causing each computer used as a controller or a network device to execute a corresponding process among the processes in the route information update method of the present invention. Note that the program of the present invention can be stored in a storage device or a storage medium.

  During the route setting process when the first packet arrives, the number of synchronization waits for updating the flow table between controllers is reduced, and the network performance is improved.

It is a conceptual diagram which shows the basic structural example of OpenFlow 0.9.0. It is a figure for demonstrating the flow of the conventional packet processing. It is a figure for demonstrating the flow of the conventional packet collation process. It is a figure for demonstrating the flow of a process in the conventional network system. It is a figure for demonstrating the flow of a process in the network system of this invention. It is a block diagram which shows the basic composition of the network system of this invention. It is a figure for demonstrating the frame format in this invention.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
As shown in FIG. 5, the network system of the present invention includes a controller, a network (NW) device, and a non-compliant network (NW) device.

  The controller controls network (NW) devices. Here, the network (NW) device corresponds to the open flow and is controlled by the controller. Non-compliant network (NW) devices do not support OpenFlow and are not controlled by any controller.

<Example 1>
Hereinafter, the flow of processing in the conventional network system will be specifically described with reference to FIG. Here, a network (NW) device A, a network (NW) device B, a network (NW) device C, and a network (NW) device D are shown as network (NW) devices compatible with OpenFlow. In addition, a non-compatible network (NW) device is shown as a network (NW) device that does not support OpenFlow.

  4 and FIG. 5, the difference between the prior art and the present invention becomes clear.

(1) 1st packet reception notification When receiving the 1st packet from the node, the network (NW) device A notifies the controller that controls the network (NW) device A that the 1st packet has been received. When receiving a notification from the network (NW) device A, the controller that controls the network (NW) device A calculates a route based on the topology information. At this time, the controller that controls the network (NW) device A has a network (NW) device controlled by a different controller on the calculated route, and is not connected to the network (NW) device on the route. When the corresponding network (NW) device exists, the setting of the route information of the network (NW) device is performed separately in the former stage and the latter stage of the incompatible network (NW) apparatus.

(2) Network (NW) device C update instruction A network (NW) device at the latter stage will be described. Here, the network (NW) device C is a network (NW) device that receives a packet from a non-compliant network (NW) device and becomes a starting point of a subsequent path. The controller that controls the network (NW) device A has the information indicating the network (NW) device C that is the starting point of the subsequent path to the controller that controls the network (NW) device C that is the starting point of the subsequent path. A list of route information of all network (NW) devices C and D in the subsequent stage is transmitted.

(3) Network (NW) Device C Update The controller that controls the network (NW) device C transmits a list of route information to the network (NW) device C. The network (NW) device C adds the list of path information received from the controller that controls the network (NW) device C as an entry of the flow table for processing the 1st packet, and updates the flow table. That is, the network (NW) device C registers, in its own flow table, an entry that associates the 1st packet with a list of route information of all the subsequent network (NW) devices C and D.

(4) Completion of update of network (NW) device C When the update of the flow table of network (NW) device C is completed, the controller that controls network (NW) device C communicates with the controller that controls network (NW) device A. To notify the update completion.

(5) Network (NW) device A update The network (NW) device in the previous stage will be described. Here, the network (NW) device A is a network (NW) device that first receives the 1st packet and becomes the start point of the previous path. When the controller that controls the network (NW) device A receives an update completion notification from the controller that controls the network (NW) device C on the calculated route, the controller updates the network (NW) device A in the flow table. Add an entry and update the flow table. In addition, the controller that controls the network (NW) device A has a previous stage existing between the previous network (NW) device A and the incompatible network (NW) device with respect to the previous network (NW) device A. A list of route information of the remaining network (NW) device B is transmitted.

<Processing in each network (NW) device>
Hereinafter, processing in each network (NW) device will also be described.
The preceding network (NW) device A adds the list of route information of the remaining previous network (NW) device B to the 1st packet, and adds the list of route information according to the entry of the flow table added by the update. The transmitted 1st packet is transmitted to the next network (NW) device B.

  In the present invention, each network (NW) device embeds a list of route information in a data area in a frame (Ether frame) carrying the 1st packet when adding the list of route information to the 1st packet. . Details of this frame format will be described later.

  The frame is a name of a PDU (protocol data unit) used in the communication of the second layer (layer 2: data link layer) of the OSI reference model, and the packet is the third layer (layer of the OSI reference model). 3: Name of PDU used in communication in the network layer).

  When the remaining network (NW) device B in the previous stage receives the 1st packet, it extracts the first route information (own route information) from the list of route information added to the 1st packet, and extracts the extracted route information. To your flow table entry.

  Here, since the network (NW) device B is the last-stage network (NW) device, the list of route information is completely removed from the 1st packet. That is, the 1st packet has the same format as a conventional packet.

  Thereafter, the remaining network (NW) device B in the previous stage transmits a 1st packet to the next non-corresponding network (NW) device in accordance with the added entry.

  The non-corresponding network (NW) device transfers the 1st packet to the network (NW) device C that is the starting point of the subsequent path by conventional routing or the like. That is, the 1st packet arrives at the network (NW) device C that is the starting point of the subsequent route from the remaining network (NW) device B in the previous stage via the non-compatible network (NW) device.

  When receiving the 1st packet, the network (NW) device C serving as the starting point of the subsequent path processes the 1st packet according to the entry of the flow table added by the update. Here, the network (NW) device C, which is the starting point of the subsequent route, extracts the first route information (own route information) from the list of route information set in the entry corresponding to the 1st packet. Then, the extracted route information is added to the entry of the own flow table. Note that the network (NW) device C that is the starting point of the subsequent route may delete the entry itself in which the route information list is set from the flow table when the route information is extracted.

  That is, when the network (NW) device C, which is the starting point of the subsequent route, is notified of the route information list, the route information list is registered as an entry, and when the 1st packet is actually received. Then, it extracts its own route information from the list of route information, and adds the extracted route information to the entry of its own flow table.

  The network (NW) device C, which is the starting point of the subsequent route, adds the remaining route information list obtained by removing the first route information (own route information) from the list to the 1st packet, and in accordance with the added entry, The 1st packet is transmitted to the next network (NW) device D.

  When the next network (NW) device D also receives the 1st packet, it extracts the route information at the head of the list (own route information) from the list of route information added to the 1st packet. Add to your flow table entry.

  Thereafter, the next network (NW) device D transmits the 1st packet to the next node according to the added entry.

<Summary of the present invention>
Thus, as shown in FIG. 5, the present invention is intended for a network including a plurality of network (NW) devices in which control functions are separated as controllers and a non-compatible network (NW) device in which control functions are not separated. And

  Before starting transmission of the 1st packet to the network (NW) device that is the starting point of the subsequent route of the non-compliant network (NW) device in the route including the non-compliant network (NW) device, Set the route information.

  For the upstream network of the non-compatible network (NW) device, the network (NW) device that first receives the 1st packet adds the route information of all the remaining network (NW) devices in the previous stage to the 1st packet and transmits it. . Since the route information is completely removed from the 1st packet in the last-stage network (NW) device, the non-corresponding network (NW) device receives the initial 1st packet to which no route information is added.

  For the latter network of the non-compliant network (NW) device, when the network (NW) device that is the starting point of the latter route receives the 1st packet from the non-compliant network (NW) device, After extracting own route information from the route information and registering it as formal route information, all the remaining route information in the subsequent stage is added to the 1st packet and transmitted.

<When there are multiple non-compatible network (NW) devices on the path>
In FIG. 5, for simplicity of explanation, only one network subsequent to the non-compliant network (NW) device is illustrated, but actually, the latter stage of another non-compliant network (NW) device is illustrated. The present invention can be implemented even if there are other networks.

  For example, it is assumed that the network (NW) devices E and F exist after the network (NW) device D shown in FIG. Here, the relationship between the network (NW) device D and the network (NW) devices E and F is assumed to be equal to the relationship between the network (NW) device B and the network (NW) devices C and D.

  At this time, when the controller that controls the network (NW) device A receives the notification of the 1st packet, as in the case of the controller that controls the network (NW) device C that is the starting point of the subsequent route, the further subsequent route For the controller that controls the network (NW) device E that is the starting point of the network, information indicating the network (NW) device E that is the starting point of the subsequent path, and all of the network (NW) devices E and F that are downstream Send a list of route information.

  Thereby, even if a plurality of non-corresponding network (NW) devices exist on the calculated route, it is possible to cope with it.

<Basic Configuration of Network System of the Present Invention>
Details of the basic configuration of the network system of the present invention will be described with reference to FIG.
Here, in the network system of the present invention, a network (NW) device at a front stage and a rear stage of a non-compliant network (NW) device and a controller that controls the network (NW) device will be described.

  The non-compatible network (NW) device has the same configuration as a conventional network (NW) device such as a switch. Alternatively, the non-corresponding network (NW) device may be a network (NW) device that is out of the control of the controller due to a failure or stoppage of the controller or disconnection of a communication line with the controller.

  In FIG. 6, the controller 10 is a controller that controls the network (NW) device upstream of the non-compatible network (NW) device shown in FIG. 5. The network (NW) device 20 is a network (NW) device upstream of the non-compatible network (NW) device shown in FIG. The controller 30 is a controller that controls a network (NW) device at the subsequent stage of the non-compatible network (NW) device shown in FIG. The network (NW) device 40 is a network (NW) device at the subsequent stage of the non-compatible network (NW) device shown in FIG.

  The controller 10 is a server machine physically separated from the network (NW) device 20 or a virtual machine (VM) that operates on the server machine. The controller 10 can manage a plurality of network (NW) devices and is connected to each network (NW) device via a dedicated channel or a secure channel (secure channel) using a normal network. Communicate with the OpenFlow protocol.

  The controller 10 includes a route calculation unit 11, a network (NW) device control unit 12, and an inter-controller control unit 13.

  The route calculation unit 11 calculates a packet transfer route. The network (NW) device control unit 12 controls the network (NW) device 20 via a dedicated line or a normal network. Here, the network (NW) device control unit 12 receives a packet from the network (NW) device 20 and transmits a list of route information to the network (NW) device 20. The inter-controller control unit 13 transmits a list of route information of the network (NW) device 40 to the controller 30 that controls the network (NW) device 40 that is not under the control of the controller 10.

  The network (NW) device 20 includes a packet processing unit 21, a flow table 22, and a flow table management unit 23.

  The packet processing unit 21 processes a packet. The flow table 22 manages route information for transferring a packet, similar to the flow table in the normal OpenFlow mechanism. The flow table management unit 23 refers / adds / updates / deletes the route information of the flow table 22 based on the route information notified from the controller 10.

  The packet processing unit 21 includes a packet transmission unit 211, a packet reception unit 212, a packet analysis unit 213, and a packet update unit 214.

  The packet transmission unit 211 transmits a packet to a physical port of the network (NW) device 20, the controller 10, or the like. The physical port of the network (NW) device 20 is connected to a node as shown in FIG. 5 or another network (NW) device. The packet receiving unit 212 receives a packet from a physical port of the network (NW) device 20, the controller 10, or the like. The packet analysis unit 213 analyzes the received packet and collates the content of the packet with the content of the entry in the flow table. The packet update unit 214 embeds route information in the packet.

  The controller 30 is a server machine physically separated from the network (NW) device 40 or a virtual machine (VM) operating on the server machine. The controller 30 can manage a plurality of network (NW) devices, and is connected to each network (NW) device by a secure channel (Secure channel) using a dedicated line or a normal network. Communicate with.

  The controller 30 has the same configuration as the controller 10. That is, the controller 30 includes a route calculation unit 31, a network (NW) device control unit 32, and an inter-controller control unit 31.

  The route calculation unit 31 calculates a packet transfer route. The network (NW) device control unit 32 controls the network (NW) device 40 via a dedicated line or a normal network. Here, the network (NW) device control unit 32 receives a packet from the network (NW) device 40 and transmits a list of route information to the network (NW) device 40. The inter-controller control unit 31 receives a list of route information of the network (NW) device 40 controlled by the controller 30 from the controller 10.

  The network (NW) device 40 has the same configuration as the network (NW) device 20. That is, the network (NW) device 40 also includes a packet processing unit 41, a flow table 42, and a flow table management unit 43.

  The packet processing unit 41 processes a packet. The flow table 42 manages route information for transferring a packet, similar to the flow table in the normal OpenFlow mechanism. The flow table management unit 43 refers / adds / updates / deletes the route information of the flow table 42 based on the route information notified from the controller 10.

  The packet processing unit 41 includes a packet transmission unit 411, a packet reception unit 412, a packet analysis unit 413, and a packet update unit 414.

  The packet transmission unit 411 transmits a packet to a physical port of the network (NW) device 40, the controller 10, or the like. The physical port of the network (NW) device 40 is connected to a node as shown in FIG. 5 or another network (NW) device. The packet receiving unit 412 receives a packet from a physical port of the network (NW) device 40, the controller 10, or the like. The packet analysis unit 413 analyzes the received packet and collates the content of the packet with the content of the entry in the flow table. The packet update unit 414 embeds route information in the packet.

<Frame format in the present invention>
In the present invention, a new protocol is prepared that defines an area in which a list of route information is embedded in a frame format. The header information of the new protocol has at least a list of route information and a header length as information. In a frame carrying a packet of a new protocol, identification information (ID) defined for the new protocol is specified in an area (field) indicating the upper protocol type.

  As shown in FIG. 7, the frame format in the present invention is based on the frame format conforming to IEEE 802.3, and includes a preamble, SFD (Start Frame Delimiter), dst (destination address), and src (transmission). Source address), TPID (Tag Protocol Identifier), TCI (Tag Control Information), Len / type (length / type), Data / LLC (Data / Logical Link Control), and FCS (Frame Security) And so on.

  In the present invention, Data / LLC is used as an area for embedding a list of route information. Data / LLC includes a header length, a path information list, and a 1st packet. The packet update unit 214 stores the list of route information notified from the controller 100 in the route information list area in Data / LLC. The packet updating unit 214 also sets the individual data length / type in the data area in Data / LLC and the identification information (ID) defined for the new protocol in Len / type.

<Description of basic operation>
In FIG. 6, the controller 10 controls the network (NW) device 20, and the controller 30 controls the network (NW) device 40. The network (NW) device 20 receives the 1st packet, and is a network (NW) device that is the starting point of the previous path. The network (NW) device 40 receives a packet from a non-compliant network (NW) device, and is a network (NW) device that is a starting point of a subsequent path.

  With reference to FIG. 6, the operation when the network (NW) device 20 receives the 1st packet will be described.

  In the network (NW) device 20, the packet receiving unit 212 receives a packet.

  The packet analysis unit 213 analyzes the packet and determines whether the frame carrying the packet is the frame format in the present invention. Here, the packet analysis unit 213 analyzes the packet, and when the identification information (ID) defined for the new protocol is added to the frame carrying the packet, or a list of route information from the frame carrying the packet Is detected, it is determined that the frame carrying the packet is the frame format in the present invention.

  When the frame carrying the packet is not in the frame format of the present invention, the packet analysis unit 213 collates the contents of the packet with the contents of the entry in the flow table 22.

  If there is no corresponding entry in the flow table 22 for the packet, the packet transmission unit 211 notifies the controller 10 to that effect.

  In the controller 10, the network (NW) device control unit 12 receives a notification of arrival of the 1st packet.

  The route calculation unit 11 calculates the route to the destination for the 1st packet.

  When a non-corresponding network (NW) device is included in the calculated route, the route calculation unit 11 includes the route information of the network (NW) device in the preceding stage of the non-supporting network (NW) device on the route and the network ( NW) Create route information for each device.

  The inter-controller control unit 13 provides information indicating that the start point of the subsequent path of the non-compatible network (NW) device is the network (NW) device 40 with respect to the controller 30 that controls the subsequent network (NW) device. A list of route information of all the network (NW) devices in the subsequent stage is transmitted.

  In the controller 30, the inter-controller control unit 33 receives from the controller 10 information indicating that the starting point of the subsequent path of the non-corresponding network (NW) device is the network (NW) device 40 and all the networks (NW) ) Receive a list of device routing information.

  The network (NW) device control unit 32 transmits a list of route information to the network (NW) device 40.

  In the network (NW) device 40, the flow table management unit 43 sets a path information list as a process (Action) for the 1st packet in the entry of the flow table 42.

  When the update of the flow table 42 of the network (NW) device 40 is completed, the packet transmission unit 411 notifies the controller 30 of the completion of the update of the flow table 42.

  In the controller 30, the inter-controller control unit 33 notifies the controller 10 of completion of the update of the flow table 42 of the network (NW) device 40.

  The controller 10 transmits the route information of all the network (NW) devices on the route from the network (NW) device 20 to the non-compliant network (NW) device to the network (NW) device 20 that is the notification source.

  In the notification source network (NW) device 20, when receiving a list of route information of all the network (NW) devices on the route from the controller 10, the packet reception unit 212 extracts its own route information and performs a flow table management unit. 23.

  The flow table management unit 23 adds a new entry to the flow table 22 and updates the flow table 22 based on its own route information.

  The packet update unit 214 adds a list of route information of network (NW) devices other than its own to a frame carrying the 1st packet according to a new protocol that defines the frame format in the present invention.

  Thereafter, the packet transmission unit 211 transmits the 1st packet according to the entry added to the flow table 22 by the update.

  In the network (NW) device 40, the packet receiving unit 412 receives the 1st packet delivered via the non-compliant network (NW) device.

  The packet analysis unit 413 analyzes the received 1st packet and confirms that the content of the 1st packet matches the entry added to the flow table 42 based on the notification from the controller 10. That is, the packet analysis unit 413 checks whether the content of the 1st packet matches the content of the entry added by the update.

  When the content of the 1st packet matches the entry added to the flow table 42, the flow table management unit 43 extracts its own route information from the list of route information included in the processing (Action) of the entry and sets it in the flow table 42. And delete the original entry. That is, the flow table management unit 43 adds its own route information as a new entry in the flow table 42 and deletes the entry in the route information list. Further, the flow table management unit 43 determines the next transmission destination network (NW) device from the route information.

  The packet update unit 414 adds a list of route information from which the route information is removed to the 1st packet.

  The packet transmission unit 411 transmits the 1st packet according to its own route information set in the flow table 42.

  As described above, in the present invention, in a network composed of network (NW) devices in which the functions of packet transfer and route control are separated, non-corresponding network (NW) devices exist on the route and straddle a plurality of controllers. When communication occurs, network performance is improved by reducing the number of times of flow table update synchronization waiting between controllers during the 1st packet processing.

<Example 2>
As another embodiment, a configuration in which controllers that control network (NW) devices before and after a non-compliant network (NW) device are the same controller is conceivable.

  For example, in the network system of the present invention shown in FIG. 5, network (NW) devices A and B and network (NW) device C are controlled by the same controller.

  In the description of the operation of the first embodiment shown in FIG. 6, when the controller 10 and the controller 30 are the same controller, the controller 10 directly performs route information of the network (NW) device 40 without performing communication between the controllers. Update.

<Example 3>
As another embodiment, a configuration in which the network (NW) devices before and after the non-compliant network (NW) device are the same network (NW) device can be considered.

  For example, in the network system of the present invention shown in FIG. 5, network (NW) devices A and B and network (NW) device C are examples of the same network (NW) device. In this case, these network (NW) devices are naturally controlled by the same controller.

  In the description of the operation of the first embodiment shown in FIG. 6, even when the network (NW) device 20 and the network (NW) device 40 are the same network (NW) device, the former stage and the latter stage of the incompatible network (NW) apparatus. The process is divided into two. In this case, the network (NW) device 20 also serves as the network (NW) device 40.

  Upon receiving notification of arrival of the 1st packet, the controller 10 sets a list of subsequent path information in the flow table 22 of the network (NW) device 20. Thereby, the network (NW) device 20 can function as a subsequent network (NW) device.

  Thereafter, the network (NW) device 20 starts transferring the 1st packet in the previous-stage route as the previous-stage network (NW) device.

  When the network (NW) device 20 receives the 1st packet from the non-compliant network (NW) device, the network (NW) device 20 extracts the first route information (own route information) from the list of the subsequent route information, and based on the extracted route information. Then, a new entry is added to the own flow table 22. Thereafter, the network (NW) device 20 adds a list of remaining path information in the subsequent stage to the 1st packet, and transmits the 1st packet to the next network (NW) device according to the added entry. At this time, the network (NW) device 20 may delete from the flow table 22 the entry in which the list of path information at the subsequent stage is set.

<Example 4>
As another embodiment, the list of route information in the subsequent stage of the non-compatible network (NW) device is not set in the network (NW) device that is the starting point of the subsequent route, but is only notified to the controller that controls it. The structure which performs is considered.

  For example, in the network system of the present invention shown in FIG. 5, a list of subsequent path information is not set in the network (NW) device C, but only in a controller that controls the network (NW) device C. This is an example of notification.

  In the description of the operation of the first embodiment shown in FIG. 6, the completion notification is transmitted from the controller 30 to the controller 10 when the list of route information is transmitted from the controller 10 to the controller 30.

  In the subsequent network (NW) device 40, the packet receiving unit 412 receives the 1st packet.

  The packet analysis unit 413 analyzes the received 1st packet and collates the content of the 1st packet with the content of the entry in the flow table 42.

  At this time, since there is no entry corresponding to the 1st packet in the flow table 42, the packet transmission unit 411 notifies the controller 30 that the 1st packet has arrived.

  Upon receiving the notification of arrival of the 1st packet, the controller 30 does not calculate a route and transmits a list of route information received from the controller 10 to the network (NW) device 40. The network (NW) device 40 extracts the first route information (own route information) from the list of route information, and adds the extracted route information to the entry of its own flow table. Thereafter, the network (NW) device 40 adds the remaining route information list to the 1st packet, and transfers the 1st packet with the route information list added to the next network (NW) device according to the added entry. To do.

  The controller 30 may update the flow table 42 by adding a new entry to the flow table 42 of the network (NW) device 40 based on the list of route information received from the controller 10. In this case, the controller 30 deletes the route information of the added entry from the route information list and notifies the network (NW) device 40 of the remaining route information list. The network (NW) device 40 adds the remaining route information list to the 1st packet, and the 1st packet with the route information list added to the next network (NW) device according to the entry added by the update. Forward.

  In other words, in the present embodiment, the operation of the subsequent network (NW) device 40 is the same as when the previous network (NW) device 20 receives the 1st packet.

  Note that the above embodiments can be implemented in combination.

<Industrial application>
The present invention can be applied to a network system including a network device in which a control function represented by OpenFlow is separated into an external controller and a conventional network device having the control function inside.

<Features of the present invention>
The present invention provides an internal environment for each network device in a mixed environment of a plurality of network devices with different controllers having control functions, or a mixed environment of a plurality of network devices belonging to different networks across an uncontrollable network device. This is a technique for updating the route information table.

  The controller sets a list of route information for the network (NW) device next to the non-compliant network (NW) device on the route where the network (NW) device and the non-compliant network (NW) device coexist.

  If the network (NW) device next to the non-compatible network (NW) device has its own route information in the set route information list, it extracts its own route information from the list and updates its own route information. To do.

  The network (NW) device next to the non-corresponding network (NW) device transfers a packet with a list of remaining route information to the next network (NW) device based on its own route information.

  That is, the present invention provides a network (NW) device in which packet transfer and path control functions are separated, an external controller having a path control function, and a conventional non-compliant network (NW) having a control function inside. The present invention relates to a network system composed of devices. In this network system, an external controller sets a list of subsequent route information for the network (NW) device next to the non-compatible network (NW) device on the route. The network (NW) device updates its route information based on the set route information list, and transfers the route information list together with the packet.

  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, 30 ... Controller 11, 31 ... Path | route calculation part 12, 32 ... Network (NW) apparatus control part 13, 33 ... Inter-controller control part 20, 40 ... Network (NW) apparatus 21, 41 ... Packet process part 211,411 ... packet transmission unit 212, 412 ... packet reception unit 213, 413 ... packet analysis unit 214, 414 ... packet update unit 22, 42 ... flow table 23, 43 ... flow table management unit

Claims (10)

A controller,
A non-compliant network device that cannot be controlled by the controller;
A network device preceding the non-compliant network device;
A network device at a subsequent stage of the non-compliant network device,
The controller is
Means for controlling the preceding network device;
Means for calculating a route to a destination for the packet notified from the network device in the previous stage;
Means for notifying the subsequent network device of the route information of the latter stage of the non-compliant network device when the non-compliant network device is present on the calculated route;
The latter network device is:
Means for receiving the packet from the non-compliant network device, extracting the route information from the subsequent route information, and adding a new entry to the flow table based on the extracted route information;
Means for adding the remaining path information of the subsequent stage to the packet;
A network system comprising: means for transmitting a packet to which the remaining path information in the subsequent stage is added according to an entry added to its own flow table. The network system according to claim 1,
Further including another controller that receives the latter-stage route information from the controller and notifies the latter-stage network device of the latter-stage route information;
The controller is
Means for notifying the other controller of the path information of the subsequent stage;
Means for receiving a response from the other controller and adding a new entry to the flow table of the preceding network device;
A network system further comprising means for notifying the upstream network device of the path information of the upstream of the incompatible network device. The network system according to claim 1,
Further including another controller that receives the latter-stage route information from the controller and notifies the latter-stage network device of the latter-stage route information;
The latter network device is:
Upon receiving the packet from the non-compliant network device, means for collating the content of the packet with the content of the entry in the flow table;
For the packet, if there is no corresponding entry in the flow table, the packet is determined as an unknown packet, and means for notifying the other controller of the packet;
A network system further comprising means for receiving the post-stage path information from the other controller. The network system according to any one of claims 1 to 3,
The network system in which the preceding network device and the subsequent network device are the same network device.   A computer used as one of a controller and a network device in the network system according to any one of claims 1 to 4. A controller,
A non-compliant network device that cannot be controlled by the controller;
A network device preceding the non-compliant network device;
In a network system including a network device subsequent to the non-compliant network device,
Controlling the network device in the previous stage by the controller;
Calculating a route to a destination for the packet notified from the previous network device by the controller;
When the non-corresponding network device is present on the calculated route by the controller, notifying the subsequent route information of the non-corresponding network device to the subsequent network device;
When the subsequent network device receives the packet from the incompatible network device, it extracts its own route information from the subsequent route information, and creates a new entry in its own flow table based on the extracted route information. And adding
Adding the remaining route information of the subsequent stage to the packet by the network device of the subsequent stage;
A route information update method comprising: transmitting a packet to which the remaining route information of the subsequent stage is added according to an entry added to its own flow table by the subsequent network device. The route information update method according to claim 6,
Notifying the other controller of the route information of the subsequent stage by the controller;
The other controller receives the latter-stage route information from the controller, and notifies the latter-stage network information to the latter-stage network device;
In response to a response from the other controller by the controller, adding a new entry to the flow table of the preceding network device;
The route information update method further comprising: notifying the previous network device of the previous route information of the incompatible network device by the controller. The route information update method according to claim 6,
Notifying the other controller of the route information of the subsequent stage by the controller;
The other controller receives the latter-stage route information from the controller, and notifies the latter-stage network information to the latter-stage network device;
When the subsequent network device receives the packet from the non-compliant network device, the content of the packet is compared with the content of the entry in the flow table;
When there is no corresponding entry in the flow table for the packet by the subsequent network device, the packet is determined as an unknown packet, and the packet is notified to the other controller;
The route information updating method further comprising: receiving the subsequent route information from the other controller by the subsequent network device. A route information update method according to any one of claims 6 to 8,
The route information update method, wherein the former network device and the latter network device are the same network device.   A program for causing a computer used as each of a controller and a network device to execute the route information update method according to any one of claims 6 to 9.

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