JP6010797B2 - Communication system and route information calculation method - Google Patents

Description

  The present invention relates to a communication system and a route information calculation method.

  In a physical network environment configured by connecting network devices such as routers, switches, firewalls, etc., the network maintainer can grasp the normality of the communication route information using commands to obtain route information. (For example, Patent Document 1). When a failure occurs in a network device or the like in a physical network environment, a maintenance person identifies the location where the failure has occurred by acquiring communication path information (for example, Patent Document 2).

  In recent years, a virtual network environment in which a network builder controls a communication path by freely combining layers 1 to 4 has been spreading. In a physical network environment, network devices that make up a network store control information that determines communication paths. In contrast, in a virtual network environment, a virtual network control device that manages control information for determining a communication path in an integrated manner is used. The communication path is changed by a maintenance person operating the virtual network control device (for example, Patent Document 3).

JP 2004-023153 A JP 2012-138778 A JP 2011-160363 A

  By the way, in a virtual network environment, a technique for acquiring path information used in a physical network environment cannot be used due to a difference in control information management. Therefore, in order to grasp communication path information and the occurrence of a failure, a mechanism or means for acquiring path information is required.

  The present invention has been made in view of the above situation, and a purpose thereof is a communication system capable of acquiring information for grasping a communication path in a communication system using a virtual network, and path information calculation. It is to provide a method.

  In order to solve the above problem, the present invention provides a physical network that each virtual network device has in a communication system using a virtual network that uses a plurality of virtual network devices and a virtual network control device that controls each virtual network device. A configuration database storing configuration information indicating other virtual network devices connected to the port for each virtual network device, and any of the virtual network devices when the virtual network device receives communication traffic A flow table storing operation information for determining whether to output the communication traffic from each physical port for each combination of the virtual network device and the physical port, and a combination of the virtual network device and the physical port in the operation information The -Extract the virtual network device connected to the physical port of the virtual network device from the configuration database using the combination of the extracted virtual network device and physical port as a search key A table calculation unit that calculates a transmission source transmission destination table indicating a combination of a transmission source and a transmission destination between the two connected virtual network devices based on the key and the search result; and And a route information calculation unit that calculates a route between any two of the virtual network devices.

  According to the present invention, in the above-described invention, the virtual network device stores the operation information based on a time elapsed after performing the operation defined in the operation information defined for the own device. An active flag indicating whether or not it is active is calculated, and the table calculation unit adds the active flag to a combination of a transmission source and a transmission destination in the transmission source transmission destination table, and the route information calculation unit In addition, information indicating a route in which all connections between the virtual network devices included in the route are active is added and output.

  Further, according to the present invention, in the invention described above, the table calculation unit matches the direction with respect to the connection between the virtual network devices based on a predetermined direction of communication traffic in the virtual network. A return flag indicating whether or not a combination of a transmission source and a transmission destination in the transmission source transmission destination table is added. A path that matches the direction between network devices and a path that is different from the direction are calculated.

  The present invention also uses a virtual network that uses a plurality of virtual network devices and a virtual network control device that controls each virtual network device, and is connected to a physical port of each of the virtual network devices. A configuration database storing configuration information indicating a virtual network device for each virtual network device, and outputting the communication traffic from any physical port of the virtual network device when the virtual network device receives the communication traffic A path information calculation method in a communication system comprising a flow table storing operation information that determines whether to perform each combination of the virtual network device and a physical port, the physical information in the virtual network device and the operation information Combination with ports Search for the other virtual network device connected to the physical port of the virtual network device from the configuration database using the combination of the extracted virtual network device and physical port as a search key. A table calculation step of calculating a transmission source transmission destination table indicating a combination of a transmission source and a transmission destination between the two connected virtual network devices based on the search key and the search result; and A route information calculation method comprising: a route information calculation step of calculating a route between any two of the virtual network devices based on a transmission destination table.

  According to the present invention, based on the configuration database indicating the physical connection configuration and the flow table for controlling the flow of communication traffic in the virtual network, the communication traffic among the virtual network devices that are physically connected By calculating a combination of virtual network devices in which a flow is defined and using the calculation result, a path between any virtual network devices can be calculated.

It is a block diagram which shows the structural example of the communication system in this embodiment. It is a block diagram which shows the structural example of the virtual network control apparatus 1 in the embodiment. It is a figure which shows the structural example of the flow memorize | stored in the flow table 11 in the embodiment. It is a figure which shows the structural example of the structural information memorize | stored in the virtual network apparatus database 12 in the embodiment. It is a figure which shows the structural example of the transmission source transmission destination list table 13 in the embodiment. It is a figure which shows an example of the flow table 11 in the embodiment. It is a 1st flowchart which shows the route information calculation process which the virtual network control apparatus 1 in the embodiment performs. It is a 2nd flowchart which shows the route information calculation process which the virtual network control apparatus 1 in the embodiment performs. It is a sequence diagram which shows an example in which a route information calculation process is utilized in the communication system of the embodiment. It is a figure which shows the example in which the flow table 11 in the embodiment was defined by the layer 1 level. It is a figure which shows the example in which the flow table 11 in the embodiment was defined by the layer 3 level. It is a figure which shows the example in which the flow table 11 in the embodiment was defined by the layer 4 level. It is a block diagram which shows the structure of 3 A of virtual networks in an Example. It is a figure which shows the structure information memorize | stored in the virtual network apparatus database 12 in the Example. It is a figure which shows the flow memorize | stored in the flow table 11 in the Example. It is a figure which shows the transmission source transmission destination list table 13 updated in the Example.

  Hereinafter, a communication system and a route information calculation method according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram illustrating a configuration example of a communication system according to the present embodiment. The communication system of this embodiment includes a virtual network 3, a monitoring server 4, a maintenance terminal 5, physical network devices 6A and 6B, service providing servers 7A and 7B, user home routers 8A and 8B, and user terminals 9A and 9B. doing. The virtual network 3 includes a virtual network control device 1 and four virtual network devices 2A to 2D. In the virtual network 3, based on control by the virtual network control device 1, the virtual network devices 2A to 2D connected to each other communicate to form a network.

  Service providing servers 7A and 7B that provide services to users are connected to the virtual network 3 via a physical network device 6B. Further, user home routers 8A and 8B located in the user's home are connected to the virtual network 3 via a physical network device 6A. A user terminal 9A used by the user is connected to the user home router 8A. In addition, a user terminal 9B used by the user is connected to the user home router 8B.

  The virtual network 3 is connected to a monitoring server 4 that monitors the operation status of the virtual network 3 and the like. The monitoring server 4 is communicably connected to the virtual network control device 1 and each of the virtual network devices 2A to 2D via a maintenance network that is different from a service network to which information according to user usage is transmitted. A maintenance terminal 5 used by a maintenance person who operates and maintains the virtual network 3 is also communicably connected to the monitoring server 4. When the monitoring server 4 receives the failure information notifying the occurrence of the failure from the virtual network devices 2A to 2D, the monitoring server 4 transmits a message notifying the maintenance terminal 5 that the failure has occurred. Based on the content of the message displayed on the maintenance terminal 5, the maintenance person operates the maintenance terminal 5 to cause the virtual network control device 1 to perform processing for grasping the state of the virtual network 3 and acquires the processing result. . Specifically, the virtual network control device 1 calculates the route between the two virtual network devices 2 specified by the route information request received from the maintenance terminal 5 and the usage status of the route. The virtual network control device 1 transmits route information indicating the calculation result to the maintenance terminal 5 as a response to the route information request.

  In the configuration example shown in the figure, the virtual network device 2A communicates with the virtual network devices 2B and 2C. The virtual network device 2B communicates with the virtual network devices 2A and 2D. The virtual network device 2C communicates with the virtual network devices 2A and 2D. The virtual network device 2D communicates with the virtual network devices 2B and 2C.

  The virtual network control device 1 centrally manages control information for controlling communication traffic in the virtual network devices 2A to 2D provided in the virtual network 3, and transmits the control information to the virtual network devices 2A to 2D. Further, the virtual network control device 1 calculates route information in the virtual network 3 in response to a request from the maintenance terminal 5. The virtual network devices 2A to 2D process communication traffic based on the control information transmitted from the virtual network control device 1.

FIG. 2 is a block diagram illustrating a configuration example of the virtual network control device 1 in the present embodiment. The virtual network control device 1 includes a storage unit 10, a control unit 20, and a communication unit 30. The storage unit 10 stores a flow table 11, a virtual network device database (virtual network device DB) 12, and a transmission source destination list table 13.
The flow table 11 includes control information for the virtual network devices 2A to 2D to control communication traffic. In each of the virtual network devices 2A to 2D, communication traffic is controlled in units called flows, and the flow table 11 defines an operation for each flow in each of the virtual network devices 2A to 2D. Hereinafter, the host names of the virtual network apparatuses 2A to 2D will be described as “hostA”, “hostB”, “hostC”, and “hostD”.

  FIG. 3 is a diagram illustrating a configuration example of a flow stored in the flow table 11 in the present embodiment. As shown in the figure, the flow table 11 is, for example, a two-dimensional table format table. The flow table 11 includes three items: a host name for identifying the virtual network devices 2A to 2D, a header field indicating conditions for identifying and specifying communication traffic, and an action indicating processing for communication traffic (packet). Have as. Each row (flow) in the flow table 11 corresponds to processing of communication traffic in each of the virtual network devices 2A to 2D. For example, in the virtual network device 2A identified by “host A”, when communication traffic satisfying “condition a1” is received, the processing defined by “processing a1” is performed on the communication traffic.

  For example, “OpenFlow”, which is a technology for realizing a virtual network environment, specifies that any of 12 header fields is used as a “header field”. The twelve header fields are the physical port number of the virtual network device 2, the source MAC address, the destination MAC address, the Ethernet (registered trademark) type, the VLAN ID, the VLAN priority, the source IP address, and the destination IP. Address, IP protocol type, IP TOS information, source L4 port number, and destination L4 port number.

  Also, three types of operations “Forward” (transfer), “Drop” (discard), and “Modify-Field” (field change) are defined as “action”. For the operation of “Forward”, any of port number, “normal”, “flood”, or “controller” is added. When the port number is added, the processing target flow is output from the port indicated by the port number of the virtual network device 2. When “normal” is added, the flow to be processed is transferred from the control of the virtual network 3 to the control of normal L2 switching or L3 routing. When “flood” is added, the flow to be processed is output from all ports other than the reception port of the virtual network device 2. When “Controller” is added, the processing target flow is output to the virtual network control device 1.

  FIG. 4 is a diagram illustrating a configuration example of configuration information stored in the virtual network device database 12 according to the present embodiment. The virtual network device database 12 is information indicating what physical configuration the connection between the virtual network devices 2A to 2D has. As shown in the figure, the virtual network device database 12 is a two-dimensional table format table, for example. The virtual network device database 12 includes a host name for identifying the virtual network devices 2A to 2D, a port number for identifying a physical port included in each virtual network device 2A to 2D, and a device connected to each physical port. It has three items of host names or connection destinations indicating information as columns. Each row in the virtual network device database 12 is configuration information. The configuration information exists for each physical port that the virtual network devices 2A to 2D have. For example, configuration information in which the host name “hostA”, the port number “p1”, and the connection destination “hostB” are associated with each other is stored in the virtual network device database 12. This configuration information indicates that the virtual network device 2B identified by the host name “hostB” is connected to the physical port “p1” of the virtual network device 2A identified by the host name “hostA”. The virtual network device database 12 is created and updated based on, for example, information collected by the virtual network control device 1 using LLDP (Link Layer Discovery Protocol).

  FIG. 5 is a diagram illustrating a configuration example of the transmission source transmission destination list table 13 in the present embodiment. The transmission source destination list table 13 stores connection information generated when route information is calculated. The connection information is generated based on information stored in the flow table 11 and the virtual network device database 12. The transmission source transmission destination list table 13 is, for example, a two-dimensional table format table. The transmission source transmission destination list table 13 includes the “transmission source” and “transmission destination” of the virtual network device 2 that can communicate in the virtual network 3, and the “active flag” for communication from the “transmission source” to the “transmission destination”. And “return flag” as four columns. Each row in the transmission source transmission destination list table 13 is connection information. Connection information exists for each path defined in the virtual network 3. The route is determined by the transmission source and the transmission destination and has a direction.

  The “active flag” is information indicating whether or not the corresponding route is active. The active flag is determined according to the time elapsed since the line (flow) defining the processing of the corresponding route in the flow table 11 is referred to. The elapsed time is, for example, the time that has elapsed since each virtual network device 2A to 2D received the target communication traffic and executed an action on the communication traffic. If the elapsed time does not exceed a predetermined elapsed time threshold, it is determined that the route is active. That is, a route that exceeds the elapsed time threshold since the flow for the route is referred to is determined not to be used, and is determined to be inactive. In the present embodiment, “1” indicates active and “0” indicates inactive. The virtual network control device 1 acquires and stores an active flag of each flow of each virtual network device 2A to 2D at a predetermined timing or periodically. The active flag of each flow acquired from each virtual network device 2A to 2D may be added to the flow table 11. Further, the elapsed time threshold value may be the same value in the virtual network devices 2A to 2D, or may be determined according to the importance of the virtual network device 2, the traffic volume, and the like.

The “return flag” is information determined when the virtual network 3 is constructed, and is information indicating the direction of communication. For example, in this embodiment, the direction from the user home routers 8A and 8B toward the service providing servers 7A and 7B is “going” communication, and the opposite direction is “returning” communication. The value of “Flag” is determined. “0” is assigned to the outgoing communication, and “1” is assigned to the returning communication. The value of the return flag is determined according to the direction of communication with respect to the route from the “transmission source” to the “transmission destination”. The return flag may be added to the virtual network device database 12.
In the transmission source destination list table 13 shown in FIG. 5, for example, connection information having a transmission source “hostA”, a transmission destination “hostC”, an active flag “0”, and a return flag “0” is stored. Yes.

  The control unit 20 includes a list table calculation unit 21 and a route information calculation unit 22. Based on the flow table 11 and the virtual network device database 12, the list table calculation unit 21 generates connection information used to calculate a route between the two virtual network devices 2 specified by the route information request. The connection information is stored in the transmission source transmission destination list table 13. The route information calculation unit 22 calculates a route between the two virtual network devices 2 specified by the route information request based on the connection information generated by the list table calculation unit 21. The communication unit 30 communicates with the virtual network devices 2 </ b> A to 2 </ b> D and the monitoring server 4 and outputs the received information to the control unit 20. In addition, the communication unit 30 transmits information input from the control unit 20 to a device indicated by the destination of the information. For example, when receiving a route information request from the maintenance terminal 5, the communication unit 30 outputs the received route information request to the control unit 20. In addition, the communication unit 30 transmits the route information calculated by the control unit 20 to the monitoring server 4.

  Hereinafter, route information calculation processing in which the control unit 20 calculates route information will be described. Here, a case where the flow shown in FIG. 6 is defined in the flow table 11 will be described. FIG. 6 is a diagram illustrating an example of the flow table 11 in the present embodiment. In the header field, a condition using the destination MAC address is defined. In the action, the transfer destination of communication traffic is determined by the port number. In the flow table 11, for example, in “host A” (virtual network device 2A), a flow for outputting communication traffic from the physical port p1 when the transmission destination is the MAC address of the physical network device 6B is defined. In the flow shown in FIG. 6, a route that passes through the virtual network device 2B is defined as a route that is normally used between the virtual network device 2A and the virtual network device 2D, and a route that passes through the virtual network device 2C is defined as a bypass route. It has been established. Further, it is assumed that the configuration information shown in FIG. 4 is stored in the virtual network device database 12. Further, it is assumed that the virtual network device 2A and the virtual network device 2D are specified in the path information request received by the virtual network control device 1.

7 and 8 are flowcharts showing the path information calculation process performed by the virtual network control device 1 according to the present embodiment. In the virtual network control device 1, when a route information request is received, a route information calculation process is started. The list table calculation unit 21 extracts a combination of the host name and the port number in the action from each flow stored in the flow table 11 (step S101).
The combination of the extracted host name and port number is {(hostA, p1), (hostA, p2), (hostA, p3), (hostB, p1), (hostB, p2), (hostC, p1), (HostC, p2), (hostD, p1), (hostD, p2), (hostD, p3)}.

The list table calculation unit 21 searches the configuration information stored in the virtual network device database 12 using the combination extracted in step S101 as a search key (host name, port number) (step S102).
The search results are {(hostA, p2, hostB), (hostA, p2, hostC), (hostB, p1, hostD), (hostB, p2, hostA), (hostC, p1, hostD), (hostC, p2, hostA), (hostD, p1, hostB), (hostD, p2, hostC)}.

The list table calculation unit 21 determines whether there is configuration information corresponding to the search key in the virtual network device database 12 (step S103). If there is no corresponding configuration information (step S103: NO), the route information The calculation process is terminated.
On the other hand, if there is a corresponding configuration (step S103: YES), the list table calculation unit 21 advances the process to step S104.

The list table calculation unit 21 generates connection information based on the extraction result (search key) in step S101 and the search result in step S102 (step S104). Specifically, the host name extracted in step S101, the host name of the connection destination of the configuration information searched in step S102, the active flag corresponding to the extracted flow, and the return flag are sent to the connection information transmission source and transmission. The first, active flag, and return flag.
Through the processing in step S104, the list table calculation unit 21 generates eight connection information and stores the generated connection information in the transmission source transmission destination list table 13. Thereby, the connection information shown in FIG. 5 is stored in the transmission source transmission destination list table 13.

When the update of the transmission source transmission destination list table 13 by the list table calculation unit 21 is completed, the route information calculation unit 22 returns to the connection information stored in the transmission source transmission destination list table 13 and connection information whose flag is “0”. It is determined whether or not there is (step S105).
When there is connection information whose return flag is “0” (step S105: YES), the route information calculation unit 22 advances the process to step S106.
On the other hand, when there is no connection information whose return flag is “0” (step S105: NO), the route information calculation unit 22 ends the route information calculation process.

The route information calculation unit 22 searches for connection information from the transmission source destination list table 13 using the virtual network device 2 specified in the route information request and the return flag “0” as a search key for (transmission source, return flag). (Step S106).
In the case illustrated here, from the connection information {(source, destination, active flag, return flag)} shown in FIG. 5 to {(hostA, hostB, 1, 0), (hostA, hostC, 0, 0) )} Is searched for, and a search result is obtained.

The path information calculation unit 22 uses the connection indicated by the transmission source and the transmission destination of the connection information of the search result in step S106 as path information (step S107). In addition, an attribute (ACTIVE) indicating that the route is active is assigned to a combination of a transmission source and a transmission destination whose active flag is “1” in the connection information.
At this stage, the route information can be expressed as, for example, the following text information.
(Route information)
・ HostA → hostB: ACTIVE
・ HostA → hostC

The route information calculation unit 22 determines whether the start point and the end point of the route included in the route information are the two virtual network devices 2 specified in the route information request (step S108).
When the two virtual network devices 2 are designated with the start point and the end point of the route included in the route information (step S108: YES), the route information calculation unit 22 advances the process to step S111.
On the other hand, when it is not the two virtual network devices 2 in which the start point and the end point of the route included in the route information are specified (step S108: NO), the route information calculation unit 22 advances the process to step S109.
In the illustrated case, since the end points of the route included in the route information are “hostB” and “hostC”, the route information calculation unit 22 advances the process to step S109.

The route information calculation unit 22 obtains the host name and return flag “0” of the virtual network device 2 different from the virtual network device 2 specified in the route information request among the start point or end point of the route included in the route information (source) , Return flag) as a search key, the connection information is searched from the transmission source destination list table 13 (step S109).
When the path information is {host A → host B, host A → host C}, in step S109, connection information {(host B, host D, 1, 0), (host C, host D, 0, 0)} is a search result.

The route information calculation unit 22 updates the route information by connecting the search results in step S109 to the route included in the route information (step S110). When the search results are connected, the connection information obtained as the search result and the end point of the route are connected.
In the illustrated case, the search result (hostB, hostD, 1, 0) corresponds to the end point of the route (hostA → hostB), and the connection from hostB to hostD indicated by the search result is the route (hostA → hostB). ) To update the path (host A → host B → host D).
Similarly, the route (host A → host C) is updated to the route (host A → host C → host D). Similarly to the processing in step S107, an attribute (ACTIVE) indicating that the route is active is given to the combination of the transmission source and the transmission destination whose active flag is “1” in the connection information. By the process of step S110, the route information of the illustrated case is as follows.
(Route information)
・ HostA → hostB → hostD: ACTIVE
・ HostA → hostC → hostD

When the process of step S110 is completed, the route information calculation unit 22 returns the process to step S108 and performs determination again.
In the illustrated case, the start point and end point of the route included in the route information match the virtual network devices 2A and 2D specified in the route information request (step S108: YES), so that the route information is calculated. The unit 22 advances the process to step S111.

The route information calculation unit 22 determines whether or not there is connection information whose return flag is “1” in the connection information stored in the transmission destination list table 13 (step S111).
When there is connection information whose return flag is “1” (step S111: YES), the route information calculation unit 22 advances the process to step S112.
On the other hand, when there is no connection information whose return flag is “1” (step S111: NO), the route information calculation unit 22 advances the process to step S117.
In the case illustrated here, since the connection information whose return flag is “1” exists in the transmission source destination list table 13, the path information calculation unit 22 advances the process to step S112.

The route information calculation unit 22 searches for connection information from the transmission source destination list table 13 using the virtual network device 2 specified in the route information request and the return flag “1” as a search key for (transmission source, return flag). (Step S112).
In the case illustrated here, from the connection information {(source, destination, active flag, return flag)} shown in FIG. 5 to {(hostD, hostC, 0, 1), (hostD, hostB, 1, 1) )} Is searched for, and a search result is obtained.

The route information calculation unit 22 adds the connection indicated by the transmission source and destination of the connection information of the search result in step S112 to the route information (step S113). Similarly to the processing in step S107, an attribute (ACTIVE) indicating that the route is active is given to the combination of the transmission source and the transmission destination whose active flag is “1” in the connection information.
In the illustrated case, the route information is as follows.
(Route information)
・ HostA → hostB → hostD: ACTIVE
・ HostA → hostC → hostD
・ HostD → hostB: ACTIVE
・ HostD → hostC

The route information calculation unit 22 determines whether the start point and the end point of the route included in the route information are the two virtual network devices 2 specified in the route information request (step S114).
When the two virtual network devices 2 are designated with the start point and the end point of the route included in the route information (step S114: YES), the route information calculation unit 22 advances the process to step S117.
On the other hand, when it is not the two virtual network devices 2 in which the start point and the end point of the route included in the route information are designated (step S114: NO), the route information calculation unit 22 advances the process to step S115.
In the illustrated case, since the end points of the route (hostD → hostB, hostD → hostC) added in step S113 are not the two designated virtual network devices 2, the route information calculation unit 22 advances the processing to step S115. .

The route information calculation unit 22 sets the host name and “1” of the virtual network device 2 different from the virtual network device 2 specified in the route information request from the start point or the end point of the route included in the route information (source, return) Connection information is searched from the transmission source destination list table 13 as a search key for the flag) (step S115).
In the illustrated case, connection information {(hostC, hostA, 0, 1), (hostB, hostA, 1, 1) for a search using (hostB, 1) and (hostC, 1) as search keys. } Is the search result.

The route information calculation unit 22 updates the route information by connecting the search results in step S115 to the route included in the route information (step S116). When the search results are connected, the connection information obtained as the search result and the end point of the route are connected.
In the illustrated case, the search result (hostC, hostA, 0, 1) corresponds to the end point of the route (hostD → hostC), and the connection from hostC to hostA indicated by the search result is the route (hostD → hostC). ) To update the path (hostD → hostC → hostA). Similarly, the route (hostD → hostB) is updated to the route (hostD → hostB → hostA). Similarly to the processing in step S107, an attribute (ACTIVE) indicating that the route is active is given to the combination of the transmission source and the transmission destination whose active flag is “1” in the connection information. By the process of step S116, the route information of the illustrated case is as follows.
(Route information)
・ HostA → hostB → hostD: ACTIVE
・ HostA → hostC → hostD
・ HostD → hostB → hostA: ACTIVE
・ HostD → hostC → hostA

When the process of step S116 is completed, the route information calculation unit 22 returns the process to step S114 and performs determination again.
In the illustrated case, since the start point and end point of the route included in the route information match the virtual network devices 2A and 2D specified in the route information request (step S114: YES), route information calculation is performed. The unit 22 advances the process to step S117.
The route information calculation unit 22 outputs the route information to the monitoring server 4 (step S117), and ends the route information calculation process.

When the virtual network control device 1 performs the above-described route information calculation process, route information indicating a route between two virtual network devices 2 designated in the virtual network 3 can be obtained. In the path information calculation process, based on the flow in which the flow of communication traffic is defined, the physical connections indicated in the virtual network device database 12 are narrowed down to connections that can be used in the virtual network 3, and then 2 The route between the two virtual network devices 2 is calculated. Thereby, the route in the virtual network 3 can be calculated.
In the illustrated case, four routes are obtained as route information. By the route information calculation process, an active route and an inactive route (redundant route) in the virtual network 3 can be calculated.

Hereinafter, a case where the route information calculation process is used in the communication system of the present embodiment will be exemplified. FIG. 9 is a sequence diagram illustrating an example in which the route information calculation process is used in the communication system according to the present embodiment. Here, a case where a failure occurs in the virtual network device 2B provided in the virtual network 3 will be described.
When a failure occurs in the virtual network device 2B, the virtual network device 2B transmits failure information indicating that a failure has occurred to the monitoring server 4 through the maintenance network (step S201).

Upon receiving the failure information, the monitoring server 4 transfers the received information to the maintenance terminal 5 used by the maintenance person and notifies that a failure has occurred in the virtual network 3 (step S202).
When receiving the failure information, the maintenance terminal 5 displays a warning message or sounds a warning sound to notify the maintenance person of the occurrence of the failure (step S203).
The maintenance terminal 5 requests the virtual network control device 1 for route information that can grasp the route in the virtual network 3 according to the operation of the maintenance person (step S204).

When receiving a route information request from the maintenance terminal 5, the virtual network control device 1 executes route information calculation processing to acquire route information (step S205).
The virtual network control device 1 transmits the acquired route information to the maintenance terminal 5 (step S206).

In this way, when a failure occurs in the virtual network 3, the route in the virtual network 3 can be grasped via the virtual network control device 1. As a result, the maintenance person can grasp whether a failure has occurred in an active route or a failure in an inactive route (redundant route) based on the failure information and the route information. It is possible to shorten the isolation time when a failure occurs. As a result, a highly available virtual network 3 can be provided. Further, not only when a failure occurs but by grasping the route information, the configuration of the route in the virtual network 3 and the validity of the setting of the flow table 11 can be confirmed.
In addition, since the service provided using the service providing servers 7A and 7B is provided via the highly available virtual network 3, the service downtime is minimized and a high quality service is provided to the user. can do.

  Note that the virtual network devices 2A to 2D may transmit the failure information to the virtual network control device 1 when a failure occurs. At this time, when receiving the failure information, the virtual network control device 1 executes a route information calculation process, and determines whether or not the virtual network device 2 that has transmitted the failure information is included in the active route. When the virtual network device 2 that has transmitted the failure information is included in an active route, the virtual network control device 1 stops the use of the flow for transferring communication traffic to the virtual network device 2 in the flow table 11. May be. Thereby, the downtime in the virtual network 3 can be reduced.

  Further, in the description of the above route information calculation processing, an example in which the flow table 11 defined at the layer 2 level is used as shown in FIG. However, it may be defined not only at the layer 2 level but also at other layer levels. For example, as shown in FIGS. 10 to 12, the flow table 11 may be defined as shown in the layer 1 level (FIG. 10), the layer 3 level (FIG. 11), and the layer 4 level (FIG. 12). .

  FIG. 10 is a diagram showing an example in which the flow table 11 in this embodiment is defined at the layer 1 level. In the header field, a condition using a port number into which communication traffic is input is defined. In the action, a port number for outputting the input communication traffic is defined. In the flow shown in FIG. 10, a route that passes through the virtual network device 2B is determined as a route that is normally used between the virtual network device 2A and the virtual network device 2D, and a route that passes through the virtual network device 2C is a detour ( Redundant route).

  FIG. 11 is a diagram showing an example in which the flow table 11 in this embodiment is defined at the layer 3 level. In the header field, a condition using an IP address of a communication traffic transmission destination is defined. In the action, the transfer destination of communication traffic is determined by the port number. In the flow shown in FIG. 11, similarly to FIG. 10, a route that passes through the virtual network device 2 </ b> B is determined as a route that is normally used between the virtual network device 2 </ b> A and the virtual network device 2 </ b> D, The route to be determined is defined as a detour (redundant route).

  FIG. 12 is a diagram showing an example in which the flow table 11 in this embodiment is defined at the layer 4 level. In the header field, a condition using a MAC address of a transmission destination of communication traffic and a TCP port number is defined. In the action, the transfer destination of communication traffic is determined by the port number. In the flow shown in FIG. 12, communication using “HTTP” as the protocol between the virtual network device 2A and the virtual network device 2D is determined to use a route via the virtual network device 2B. Further, communication using “HTTPS” as a protocol is determined to use a route via the virtual network device 2C.

  Even if the flow table 11 is defined as shown in FIGS. 6 and 10 to 12, the virtual network control device 1 can calculate route information by performing route information calculation processing. Specifically, the list table calculation unit 21 can extract a combination of the virtual network device 2 (host name) and the port number whose operation is defined in the flow in step S101 of the path information calculation process. Route information can be calculated.

(Example)
Here, the route information calculation process when the configuration is different from the virtual network 3 in the above description will be described.
FIG. 13 is a block diagram illustrating a configuration of the virtual network 3A in the embodiment. Here, the configuration of the virtual network 3A and the physical network devices 6A and 6B are shown by omitting the monitoring server 4, the maintenance terminal 5, the service providing servers 7A and 7B, the user home routers 8A and 8B, and the user terminals 9A and 9B. ing. The virtual network 3A shown in the figure includes a virtual network control device 1 and six virtual network devices 2A to 2F. Based on the control by the virtual network control device 1, the virtual network devices 2A to 2F connected to each other communicate to form a network. The host names of the virtual network devices 2A to 2F will be described as “hostA”, “hostB”, “hostC”, “hostD”, “hostE”, and “hostF”. Each of the virtual network devices 2A to 2F has three physical ports p1 to p3.

  FIG. 14 is a diagram illustrating configuration information stored in the virtual network device database 12 according to the embodiment. In the virtual network device database 12, virtual network devices 2A to 2F or physical network devices 6A and 6B connected to the respective physical ports p1 to p3 of the virtual network devices 2A to 2F are shown.

  FIG. 15 is a diagram illustrating a flow stored in the flow table 11 in the embodiment. In the flow shown in the figure, a route passing through the virtual network device 2B and the virtual network device 2D is set as a route normally used between the virtual network device 2A and the virtual network device 2F. In addition, a route from the virtual network device 2A through the virtual network device 2C, a route from the virtual network device 2E to the virtual network device 2F, and the like are set as a bypass route (redundant route).

  Also in this embodiment, the value of the return flag is in the direction from the physical network device 6B to which the service providing servers 7A and 7B are connected to the physical network device 6A to which the user home routers 8A and 8B are connected. On the other hand, “1” is set in advance, and “0” is set in advance in the opposite direction.

A path information calculation process when the virtual network control apparatus 1 receives a path information request specifying the virtual network apparatus 2A and the virtual network apparatus 2F in the virtual network 3A set as described above will be described.
When the route information request is input, the list table calculation unit 21 extracts a combination of the host name and the port number in the action from the flow table 11 (FIG. 15), and uses the extracted host name and port number as a search key. The configuration information is retrieved from the virtual network device database 12 (steps S101 to S102).
The list table calculation unit 21 generates connection information based on the extraction result (search key) and the search result, and stores the generated connection information in the transmission source transmission destination list table 13 (step S104). FIG. 16 is a diagram illustrating the transmission source transmission destination list table 13 updated in the present embodiment.

The route information calculation unit 22 searches for connection information from the transmission source destination list table 13 using the virtual network device 2 specified in the route information request and the return flag “0” as a search key for (transmission source, return flag). The search result is used as route information (steps S106 to S107). The route information at this stage is as follows.
(Route information)
・ HostA → hostB: ACTIVE
・ HostA → hostC

The path information calculation unit 22 searches for connection information from the transmission destination list table 13 using the host name “hostB” and the return flag “0”, and the host name “hostC” and the return flag “0” as search keys. The search result is linked to the route information and updated (steps S109 to S110). The route information at this stage is as follows.
(Route information)
・ HostA → hostB → hostD: ACTIVE
・ HostA → hostB → hostE
・ HostA → hostC → hostE
・ HostA → hostC → hostD

Since the start point and end point of the route included in the route information do not match the virtual network device 2 specified in the route information request (step S108: NO), the route information calculation unit 22 updates the route information again. It performs (step S109-step S110). The route information at this stage is as follows.
(Route information)
・ HostA → hostB → hostD → hostF: ACTIVE
・ HostA → hostB → hostE → hostF
・ HostA → hostC → hostE → hostF
・ HostA → hostC → hostD → hostF

The route information calculation unit 22 determines that the return flag is “1” because the start point and the end point of the route included in the route information match the virtual network device 2 specified in the route information request (step S108: YES). The route is calculated based on the connection information.
The route information calculation unit 22 searches for connection information from the transmission source destination list table 13 using the virtual network device 2 specified in the route information request and the return flag “1” as a search key for (transmission source, return flag). Then, the search result is added to the route information (steps S112 to S113). The route information at this stage is as follows.
(Route information)
・ HostA → hostB → hostD → hostF: ACTIVE
・ HostA → hostB → hostE → hostF
・ HostA → hostC → hostE → hostF
・ HostA → hostC → hostD → hostF
・ HostF → hostE: ACTIVE
・ HostF → hostD

The path information calculation unit 22 searches for connection information from the transmission destination list table 13 using the host name “hostE” and the return flag “1”, and the host name “hostD” and the return flag “1” as search keys. The search result is updated by connecting to the route information (steps S115 to S116). The route information at this stage is as follows.
(Route information)
・ HostA → hostB → hostD → hostF: ACTIVE
・ HostA → hostB → hostE → hostF
・ HostA → hostC → hostE → hostF
・ HostA → hostC → hostD → hostF
・ HostF → hostD → hostB: ACTIVE
・ HostF → hostE → hostB
・ HostF → hostE → hostC
・ HostF → hostD → hostC

The route information calculation unit 22 updates the route information again because the start point and end point of the route included in the route information do not match the virtual network device 2 specified in the route information request (step S114: NO). It performs (step S115-step S116). The route information at this stage is as follows.
(Route information)
・ HostA → hostB → hostD → hostF: ACTIVE
・ HostA → hostB → hostE → hostF
・ HostA → hostC → hostE → hostF
・ HostA → hostC → hostD → hostF
・ HostF → hostD → hostB → hostA: ACTIVE
・ HostF → hostE → hostB → hostA
・ HostF → hostE → hostC → hostA
・ HostF → hostD → hostC → hostA

  The route information calculation unit 22 outputs the calculated route information because the start point and end point of the route included in the route information match the virtual network device 2 specified in the route information request (step S114: YES). (Step S117), the route information calculation process is terminated.

  As described above, the active route and the redundant route can be grasped from the route information obtained by the route information calculation process. For example, when a failure occurs in the virtual network device 2D in the active route, the failure that has occurred can be avoided by changing the flow table 11 to use a route that does not pass through the virtual network device 2D. .

In addition, although the case where it has four virtual network devices 2 and the case where it has six virtual network devices 2 was illustrated as a structure of a virtual network, five virtual network devices 2 or seven or more A configuration having the virtual network device 2 may also be used.
Further, the configuration in which the virtual network control device 1 includes the list table calculation unit 21 and the route information calculation unit 22 has been described. However, the communication system includes other devices including the list table calculation unit 21 and the route information calculation unit 22. You may have. Further, the list table calculation unit 21 and the route information calculation unit 22 may be provided as independent devices. In this case, these devices communicate with the virtual network control device 1 via the maintenance network and calculate route information.

  The program for realizing the function of the virtual network control device 1 in FIG. 1 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into the computer system and executed to execute a route. Information calculation processing may be performed. Here, the “computer system” includes an OS and hardware such as peripheral devices. The “computer system” includes a WWW system having a homepage providing environment (or display environment). The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Further, the “computer-readable recording medium” refers to a volatile memory (RAM) in a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included.

  The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

DESCRIPTION OF SYMBOLS 1 ... Virtual network control device 2, 2A, 2B, 2C, 2D, 2E, 2F ... Virtual network device 3, 3A ... Virtual network 4 ... Monitoring server 5 ... Maintenance terminal 6A, 6B ... Physical network device 7A, 7B ... Service provision Server 8A, 8B ... User home router 9A, 9B ... User terminal 10 ... Storage unit 11 ... Flow table 12 ... Virtual network device database 13 ... Source transmission destination list table 20 ... Control unit 21 ... List table calculation unit 22 ... Path information Calculation unit 30 ... communication unit

Claims (4)

In a communication system using a virtual network using a plurality of virtual network devices and a virtual network control device that controls each virtual network device,
A configuration database storing configuration information indicating other virtual network devices connected to physical ports of the virtual network devices for each virtual network device;
Operation information defining which physical port of the virtual network device outputs the communication traffic when the virtual network device receives the communication traffic is stored for each combination of the virtual network device and the physical port. A flow table,
The combination of the virtual network device and the physical port in the operation information is extracted from the flow table, and the combination of the extracted virtual network device and the physical port is used as a search key from the configuration database to the physical port of the virtual network device. Search for other connected virtual network devices, and based on the search key and the search result, a transmission source destination indicating a combination of a transmission source and a transmission destination between the two connected virtual network devices A table calculation unit for calculating a table;
A path information calculation unit that calculates a path between any two of the virtual network devices based on the source transmission destination table ;
The virtual network device is:
Based on the time elapsed since the operation specified in the operation information determined for the device itself is performed, an active flag indicating whether the operation information is active is calculated,
The table calculation unit
The active flag is added to the combination of the transmission source and the transmission destination in the transmission source transmission destination table,
The route information calculation unit
Adding and outputting information indicating a path in which all connections between the virtual network devices included in the path are active and a path including inactivity;
A communication system characterized by the above. In a communication system using a virtual network using a plurality of virtual network devices and a virtual network control device that controls each virtual network device,
A configuration database storing configuration information indicating other virtual network devices connected to physical ports of the virtual network devices for each virtual network device;
Operation information defining which physical port of the virtual network device outputs the communication traffic when the virtual network device receives the communication traffic is stored for each combination of the virtual network device and the physical port. A flow table,
The combination of the virtual network device and the physical port in the operation information is extracted from the flow table, and the combination of the extracted virtual network device and the physical port is used as a search key from the configuration database to the physical port of the virtual network device. Search for other connected virtual network devices, and based on the search key and the search result, a transmission source destination indicating a combination of a transmission source and a transmission destination between the two connected virtual network devices A table calculation unit for calculating a table;
A path information calculation unit that calculates a path between any two of the virtual network devices based on the source transmission destination table ;
The table calculation unit
Based on a predetermined direction of communication traffic in the virtual network, a return flag indicating whether or not the direction matches a connection between the virtual network devices is a source in the source destination table. Add to the combination with the destination,
The route information calculation unit
A communication system characterized in that , based on the return flag, a route that matches the direction between the two arbitrary virtual network devices and a route that is different from the direction are calculated . Configuration showing another virtual network device connected to a physical port of each of the virtual network devices using a virtual network using a plurality of virtual network devices and a virtual network control device that controls each virtual network device A configuration database that stores information for each virtual network device, and an operation that determines which physical port of the virtual network device outputs the communication traffic when the virtual network device receives the communication traffic A path information calculation method in a communication system comprising a flow table storing information for each combination of the virtual network device and a physical port,
The virtual network control device extracts a combination of the virtual network device and a physical port in the operation information from the flow table, and uses the extracted combination of the virtual network device and the physical port as a search key from the configuration database. The other virtual network device connected to the physical port of the virtual network device is searched, and based on the search key and the search result, the source and destination between the two connected virtual network devices A table calculation step for calculating a transmission source transmission destination table indicating the combination;
Flag calculation for calculating an active flag indicating whether or not the operation information is active based on the time elapsed since the virtual network device performed the operation specified in the operation information determined for the own device. Steps,
A flag adding step in which the virtual network control device adds the active flag to a combination of a transmission source and a transmission destination in the transmission source transmission destination table;
A path information calculating step in which the virtual network control apparatus calculates a path between any two of the virtual network apparatuses based on the transmission source destination table ;
An output step in which the virtual network control apparatus adds and outputs information indicating a path in which all connections between the virtual network apparatuses included in the path are active and a path including inactivity; and
A route information calculation method characterized by comprising: Configuration showing another virtual network device connected to a physical port of each of the virtual network devices using a virtual network using a plurality of virtual network devices and a virtual network control device that controls each virtual network device A configuration database that stores information for each virtual network device, and an operation that determines which physical port of the virtual network device outputs the communication traffic when the virtual network device receives the communication traffic A path information calculation method in a communication system comprising a flow table storing information for each combination of the virtual network device and a physical port,
The virtual network control device extracts a combination of the virtual network device and a physical port in the operation information from the flow table, and uses the extracted combination of the virtual network device and the physical port as a search key from the configuration database. The other virtual network device connected to the physical port of the virtual network device is searched, and based on the search key and the search result, the source and destination between the two connected virtual network devices A table calculation step for calculating a transmission source transmission destination table indicating the combination;
The virtual network control device, based on a predetermined direction of communication traffic in the virtual network, a return flag indicating whether or not the direction matches a connection between the virtual network devices, An additional step to be added to the combination of the transmission source and the transmission destination in the transmission destination table;
A path information calculating step in which the virtual network control apparatus calculates a path between any two of the virtual network apparatuses based on the transmission source destination table;
Have
In the route information calculation step, based on the return flag, a route that matches the direction between the two arbitrary virtual network devices and a route that is different from the direction are calculated.
A route information calculation method characterized by the above.

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