WO2015133059A1 - Route control apparatus, route control method, and route control program - Google Patents

Abstract

This invention provides a route control apparatus that, even if there is a difference in function between packet transfer apparatuses included in a network, can determine an appropriate packet transfer route, while making use of the functions. A transfer route calculation means (92) calculates a transfer route including packet transfer apparatuses having respective functions for a packet. A setting means (93) performs a setting to cause the packet transfer apparatuses on the transfer route calculated by the transfer route calculation means (92) to transfer the packet along the transfer route.

Description

Route control device, route control method, and route control program

The present invention relates to a route control device, a route control method, and a route control program for controlling a packet transfer route by controlling the packet transfer device.

FIG. 27 is an explanatory diagram showing an example of a network configuration to which OpenFlow is applied. In the network configuration shown in FIG. 27, an OpenFlow switch (hereinafter referred to as OFS) 502 that transfers a packet and an OpenFlow controller (hereinafter referred to as OFC) 501 that determines a packet transfer path are separated. Provided. A host 503 is connected to the OFS 502. Then, the OFC 501 determines a route from the transmission source host to the transmission destination host of the packet.

The OFS 502 holds information called a flow table that defines the next transfer destination for the received packet. The OFS 502 inquires of the OFC 501 about the transfer destination of the packet when the transfer destination of the received packet is not indicated in the flow table or when the destination information existing in the packet cannot be interpreted by the OFS 502 itself.

The OFC 501 calculates a packet transfer route, and issues a flow table update instruction to a plurality of OFSs 502 on the transfer route so that the packet is transferred according to the determined transfer route in order to construct the transfer route. . Then, each OFS 502 on the transfer path updates the flow table, thereby constructing a transfer path from the packet transmission source to the transmission destination.

The OFC 501 is also responsible for managing the OFS 502, and grasps the topology indicating where the OFS 502 exists and how it is connected. The OFC 501 uses this topology information for packet transfer path calculation. Further, when the OFS 502 fails or the network configuration is expanded, the network administrator newly introduces the OFS 502. At this time, the OFC 501 uses the function of collecting information of the OFS 502, and the OFS 502 holds the OpenFlow protocol version supported by the newly connected OFS 502 and the Internet Protocol version (IPv4 / IPv6). Understand what functions are.

An example of a network system to which OpenFlow is applied is described in Patent Document 1, for example.

Also, Patent Document 2 describes a device that acquires the functional units and setting information of each node in cooperation with other terminals.

Further, Patent Document 3 describes a method for determining a destination address using a function indicator for identifying a service executed on a network device.

JP 2013-143698 A JP 2012-175628 A Special table 2011-501602

In OpenFlow, the protocol between OFC and OFS is standardized. However, there are cases where the vendors of OFC and OFS are different, or the vendors of each OFS are different. And, there are cases where differences exist in the functions installed for each OFS due to different vendors. Also, even if the same vendor's OFS, the supported OpenFlow protocol version is different, or there is a difference in the presence or absence of vendor-specific functions that the vendor has originally expanded. May exist.

Therefore, the network administrator defines what functions should be provided for the entire network, and in order to be able to provide that function on the packet transfer path from the source host to the destination host, I had to figure out if I had or didn't have the function it should provide. Then, the network administrator has to set a detoured transfer route that goes through the OFS having the function. For example, when the function to be provided is a specific function A, it is necessary to construct a detour transfer path that goes through the OFS that owns the function A. However, in a large-scale network in which the number of OFSs present in the network is enormous, it is difficult for the network administrator to grasp the difference between the functions installed in each OFS.

If there are differences in the OFS in the network, such as differences in the version of OpenFlow protocol or the presence or absence of vendor-specific functions, there are few OFS in a small network. Functional differences can be easily grasped.

However, in a large-scale network, there are many connected OFS, and it is difficult to grasp the function of each OFS.

Therefore, in order to provide a certain function as a whole network, it is difficult for a network administrator to construct a transfer route that takes into account the functional difference of OFS. Therefore, in order to reduce the functional difference between OFS, the network administrator physically connects a plurality of OFSs having the same function so as to be adjacent as much as possible, and the plurality of OFSs having the same function are connected. A domain is defined as a set. As a result, since there are few functional differences in the domain, it is easy for a network administrator to construct a route that is closed in the domain.

However, as the size of the network grows larger, there are cases where the packet source and destination belong to different domains, and the network administrator has to set a route that spans between domains. It has increased. When the packet transmission source and the transmission destination cross the domain, the functional difference is small between OFSs existing in the domain, but the functional difference exists between OFSs belonging to different domains. That is, a functional difference exists between domains that are a set of a plurality of OFS. As a result, in order to provide a certain function as a whole network, the difficulty level of constructing a transfer path in consideration of the functional difference of OFS has been further increased.

Also, the packet transfer path is calculated based on the packet source and destination information. Therefore, even if an OFS corresponding to a new version of OpenFlow protocol or a high-performance OFS equipped with many vendor-specific functions are introduced, the transfer path may not pass through a high-function OFS. Therefore, there are cases where the function can be provided as a network and cases where the function cannot be provided.

When there is a case where the function can be provided as a network and a case where the function cannot be provided as a network, the network administrator has unified the network not to provide the function. Specifically, the network administrator has lowered the version of OpenFlow protocol, or turned off some of the vendor-specific functions in accordance with other OFS functions.

Also, when an OFS having a new function is introduced into the network, it is possible to replace all of the OFSs already existing in the network with the OFS having the new function. However, the overall replacement cost of OFS is high. In particular, the number of OFS present in a large-scale network is enormous, and the replacement cost of these OFS is very high. For this reason, as the scale of the network becomes larger, it has been difficult to improve the functionality of the entire network.

Therefore, the present invention provides a route control device, a route control method, and a route control device that can determine an appropriate packet transfer route while making use of the function even when there is a difference in function between packet transfer devices included in the network. An object is to provide a routing program.

A path control apparatus according to the present invention is a path control apparatus that controls a transfer path of a packet that passes through a packet transfer apparatus, a transfer path calculation unit that calculates a transfer path including a packet transfer apparatus having a function for a packet, And a setting unit configured to set each packet transfer device on the transfer route calculated by the transfer route calculating unit to transfer the packet along the transfer route.

A route control method according to the present invention is a route control method for controlling a transfer route of a packet passing through a packet transfer device, and calculates a transfer route including a packet transfer device having a function for a packet, Each packet transfer apparatus is set to transfer a packet along a transfer path.

A route control program according to the present invention is a route control program installed in a computer that controls a transfer route of a packet passing through a packet transfer device, and the computer includes a packet transfer device having a function for a packet. A transfer route calculation process for calculating a route, and a setting process for setting each packet transfer device on the transfer route calculated in the transfer route calculation process to transfer a packet along the transfer route. Features.

According to the present invention, even when there is a difference in function between packet transfer apparatuses included in the network, an appropriate packet transfer path can be determined while making use of the function.

It is explanatory drawing which shows the example of the network system to which this invention is applied. It is a block diagram which shows the structural example of OFC. It is a schematic diagram which shows the example of a functional topology. It is a schematic diagram which shows the example of a functional topology. It is a flowchart which shows the example of processing progress of OFC. It is a sequence diagram which shows the example of the process progress of step S1. It is a schematic diagram which shows the example of the information memorize | stored in an OFS possession function management part. It is a schematic diagram which shows the example of a functional topology. It is a schematic diagram which shows the example of the transfer path | route of the packet which connects hosts. It is a schematic diagram which shows the example of a network structure. It is explanatory drawing which shows the difference of the mounting function of each OFS shown in FIG. FIG. 6 is a schematic diagram showing a function topology corresponding to each of functions 1 to 5; It is explanatory drawing which shows the content of the flow table. It is a flowchart which shows the example of a process progress of the functional topology calculation part in step S4. It is explanatory drawing which shows the example of each combination of the transmission origin host specified by step S31, and a transmission destination host. FIG. 6 is an explanatory diagram illustrating an example of function feature information of functions 1 to 5; It is explanatory drawing which shows the calculation result of a transfer path | route. It is explanatory drawing which shows the calculation result of a transfer path | route. It is explanatory drawing which shows the calculation result of a transfer path | route. It is explanatory drawing which shows the calculation result of a transfer path | route. It is explanatory drawing which shows the recalculation result of a transfer path | route. It is explanatory drawing which shows the recalculation result of a transfer path | route. It is explanatory drawing which shows the recalculation result of a transfer path | route. It is explanatory drawing which shows the recalculation result of a transfer path | route. It is a block diagram which shows the structural example of OFC in the 2nd Embodiment of this invention. It is a block diagram which shows the example of the minimum structure of this invention. It is explanatory drawing which shows the example of the network structure to which OpenFlow is applied.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, the outline of the present invention will be described. In the present invention, the OFC (Open Flow Controller) comprehensively covers not only the physical topology of the OFS (Open Flow Switch) but also all of the OFSs possessing functions for each function installed in the OFS. Define the connected diagram as a functional topology. The functional topology is a logical topology and does not depend on the physical connection between OFS. There is a correlation of having the same function even between OFSs that are not physically directly connected. Therefore, a functional topology that connects between OFSs having the same function can be defined as a logical topology. By defining a functional topology and calculating a transfer path close to the functional topology, a transfer path centered on the high-function OFS can be constructed. At this time, if the OFS having the function provided as the entire network is not physically connected, the OFS that does not have the function is used as a node that holds a plurality of OFS that have the function. It is done. In the present invention, a route centering on high-function OFS can be constructed as a whole network based on the functional topology, and even if some OFS does not have a function, the network as a whole provides that function. can do.

Embodiment 1. FIG.
FIG. 1 is an explanatory diagram showing an example of a network system to which the present invention is applied. The network system illustrated in FIG. 1 includes an OFC 101 and an arbitrary number of OFSs 102. The OFC 101 corresponds to the path control device of the present invention. The OFS 102 corresponds to a packet transfer device. FIG. 1 illustrates a case where there are six OFSs 102. When the individual OFSs 102 are distinguished, they are described as OFS 102-1 and OFS 102-2. In addition, the host 103 is connected to the OFS 102. The number of hosts is arbitrary. FIG. 1 illustrates a case where there are two hosts 103. When distinguishing the individual hosts 103, they are described as the host 103-1, the host 103-2, and the like.

FIG. 2 is a block diagram illustrating a configuration example of the OFC 101. The OFC 101 includes an OFS management unit 301, a functional topology calculation unit 304, a functional topology management unit 305, an update instruction unit 306, and a connection processing unit 307. The OFS management unit 301 includes an OFS possessed function management unit 302.

The OFS management unit 301 manages information of the OFS 102 existing in the network. Specifically, the OFS management unit 301 acquires information on functions held by the OFS 102 from each OFS 102 existing in the network.

The OFS possessed function management unit 302 retains information indicating whether each OFS 102 possesses a function for each function. The OFS management unit 301 acquires information about the functions held by the OFS 102 from each OFS 102, and stores information indicating whether each OFS 102 has a function for each function in the OFS held function management unit 302.

The functional topology calculation unit 304 calculates a functional topology for each function based on information held in the OFS possessed function management unit 302 (information indicating whether each OFS 102 has a function for each function). To do. The functional topology related to a certain function is a diagram in which all OFSs 102 having the function are comprehensively connected without depending on the presence or absence of actual connection. In a functional topology related to a certain function, all of the OFSs 102 in the functional topology have the function. Then, each OFS 102 in the functional topology is connected to all OFSs 102 other than itself that own the function. This connection does not depend on whether or not the network is actually connected. Therefore, even if the OFSs 102 are not actually connected, the OFSs 102 having the same function are connected in the functional topology related to the function. An example of functional topology is shown below.

In the network system shown in FIG. 1, it is assumed that the OFS 102 having a specific function is only the OFS 102-2, OFS 102-5, and OFS 102-6. FIG. 3 shows a functional topology calculated by the functional topology calculation unit 304 as a functional topology related to the function. In this example, in the functional topology 303, OFS 102-2, OFS 102-5, and OFS 102-6 are connected. As shown in FIG. 3, each of the OFS 102-2, OFS 102-5, and OFS 102-6 is connected to all of the OFSs other than itself in the functional topology 303.

Further, in the network system shown in FIG. 1, it is assumed that the OFS 102 having another specific function is only the OFS 102-2, OFS 102-3, OFS 102-4, and OFS 102-5. FIG. 4 shows a functional topology calculated by the functional topology calculation unit 304 as a functional topology related to the function. In this example, in the function topology 303, OFS 102-2, OFS 102-3, OFS 102-4, and OFS 102-5 are connected. Also in the example illustrated in FIG. 4, each OFS in the functional topology 303 is connected to all OFSs other than itself in the functional topology 303.

The functional topology management unit 305 manages the functional topology calculated by the functional topology calculation unit 304. Specifically, the function topology management unit 305 holds each function topology calculated for each function by the function topology calculation unit 304.

Further, the functional topology calculation unit 304 calculates a packet transfer path based on the functional topology.

The update instruction unit 306 instructs each OFS 102 on the transfer path to update the flow table based on the transfer path calculated by the functional topology calculation unit 304.

The connection processing unit 307 performs connection processing (establishment of communication) with the OFS 102 in response to a request from the OFS 102.

Further, the OFC 101 collects information for specifying the physical topology from each OFS 102 and, based on the information, specifies a physical topology specifying unit (not shown) that specifies the physical topology of the OFS 102 and the host 103. Also have. The physical topology specifying unit appropriately specifies and holds the latest physical topology.

The OFS management unit 301, the functional topology calculation unit 304, the update instruction unit 306, the connection processing unit 307, and the physical topology identification unit (not shown) are realized by a CPU of a computer that operates according to a path control program, for example. In this case, for example, the CPU reads a path control program from a program recording medium such as a program storage device (not shown) of the computer, and according to the path control program, the OFS management unit 301, the function topology calculation unit 304, and the update instruction unit 306. , The connection processing unit 307, and the physical topology specifying unit. Further, the OFS management unit 301, the functional topology calculation unit 304, the update instruction unit 306, the connection processing unit 307, and the physical topology identification unit may be realized by separate hardware.

Next, the processing progress of the present invention will be described.
FIG. 5 is a flowchart illustrating an example of processing progress of the OFC 101. As shown in FIG. 5, the OFC 101 performs OFS-OFC connection processing (step S1), each OFS possessed function grasping processing (step S2), function topology creation processing (step S3), and route calculation processing giving priority to the function topology. (Step S4) and flow table update processing (Step S5) are executed in order. Hereinafter, each of these processes will be described.

First, the OFS-OFC connection process (step S1) will be described. When connecting the OFS 102 to the network system shown in FIG. 1, the OFS 102 issues a connection request to the OFC 101. Then, OFS and OFS are connected to each other using OFS 102 as a managed subordinate OFS. Then, the OFC 101 recognizes the newly connected OFS 102 and acquires information regarding the functions possessed by the OFS 102.

FIG. 6 is a sequence diagram showing an example of processing progress of step S1. The OFS-OFC connection process (step S1) is a process in which when the OFC 101 receives a connection request from the OFS 102, the OFS 102 is used as a managed subordinate OFS and the OFC and OFS connect to each other.

When connecting the OFS 102 to the network system, the OFS 102 first transmits a TCP (Transmission Control Protocol) connection establishment request to the OFC 101, and the connection processing unit 307 of the OFC 101 receives the TCP connection establishment request. Then, the OFS 102 and the connection processing unit 307 establish a communication path between the OFS 102 and the OFC 101 (Steps S21 and S22).

Next, the OFS 102 transmits a message (Hello message) to the communication path (step S23), and upon receiving the message, the connection processing unit 307 transmits a response to the message to the OFS 102 (step S24). By receiving this response, the OFS 102 confirms that there is no problem in the established communication path.

After the communication path is established, the OFS management unit 301 of the OFC 101 transmits the retained function information provision instruction 202 to the OFS 102 in order to grasp the retained function of the OFS 102 (step S25). The retained function information provision instruction 202 is a command for requesting provision of information regarding the function of the OFS 102. Specifically, the OFS management unit 301 uses the retained function information provision instruction 202 to support the OpenFlow protocol version supported by the OFS 102, the Internet Protocol version (IPv4 / IPv6), and the functions possessed by the OFS 102 ( For example, it is requested to provide information such as vendor-specific functions. Then, the OFS 102 transmits such information to the OFC 101 in response to the retained function information provision instruction 202 (step S26). As a result, the OFS management unit 301 stores information such as the OpenFlow protocol version supported by the OFS 102, the Internet Protocol version (IPv4 / IPv6), and the functions (eg, vendor-specific functions) possessed by the OFS 102. get.

Thereafter, the OFS management unit 301 transmits a setting change instruction 203 to the OFS 102 (step S27). The OFS 102 changes the settings according to the network topology, the network load, and the functions possessed by the OFS 102 in accordance with the setting change instruction 203. Further, the OFS 102 notifies the OFC 101 of a response to the setting change instruction 203 (step S28).

With the above processing, the OFS-OFC connection processing (step S1) is completed, and the OFS 102 is connected to the network as an OFS under the management of the OFC 101.

The OFC 101 executes the process of step S1 for each OFS 102 connected to the network system. Thereafter, the OFC 101 executes the possessed function grasping process (step S2) of each OFS. Step S2 will be described.

By executing the process of step S1 for each OFS 102 connected to the network system, the OFS management unit 301 acquires information on the function of the OFS 102 from each OFS 102. For example, the OFS management unit 301 acquires information such as the OpenFlow protocol version, the Internet Protocol version (IPv4 / IPv6), and the functions (for example, vendor-specific functions) possessed by the OFS 102 from each OFS 102. Yes. In step S <b> 2, the OFS management unit 301 grasps the function possessed by each OFS 102 based on the information. Then, the OFS management unit 301 generates information indicating whether each OFS 102 has a function for each function, and stores the information in the OFS possessed function management unit 302.

FIG. 7 is a schematic diagram showing an example of information stored in the OFS possessed function management unit 302. FIG. 7 illustrates a case where there are five types of functions. For function 1, each OFS 102 indicates whether or not it has function 1. The same applies to functions 2-5. Note that FIG. 7 is an example, and the storage format (data structure) of information indicating whether each OFS 102 has a function for each function is not limited.

After step S2, the functional topology calculation unit 304 executes a functional topology creation process (step S3). The function topology creation process is a process for creating a function topology based on information stored in the OFS possessed function management unit 302 (information indicating whether each OFS 102 possesses a function for each function).

The functional topology is a diagram in which OFSs 102 having the same function are connected to each other, and each OFS 102 having the function is connected to all OFSs 102 other than itself having the function. As already described, the functional topology is a logical topology, and the OFSs 102 having the same function are connected in the functional topology even if they are not physically connected.

The functional topology calculation unit 304 creates a functional topology for every function held by the OFS 102 under the management of the OFC 101. Then, the functional topology calculation unit 304 causes the functional topology management unit 305 to store each functional topology created for each function.

For example, in the network system illustrated in FIG. 1, it is assumed that the information illustrated in FIG. 7 is stored in the OFS possessed function management unit 302 in step S2. The function topology calculation unit 304 creates a function topology 303 shown in FIG. 8 as the function topology of function 1 based on the information illustrated in FIG. As shown in FIG. 7, OFS 102-1 and OFS 102-6 are the only OFS possessing function 1. Therefore, the function topology calculation unit 304 generates a function topology 303 (see FIG. 8) in which the OFS 102-1 and OFS 102-6 are connected as the function 1 function topology. As shown in FIG. 1, OFS 102-1 and OFS 102-6 are not connected. However, in the functional topology, OFSs 102 having the same function (function 1 in this example) are connected without depending on the presence or absence of physical connection.

Fig. 8 shows the functional topology of function 1. The function topology management unit 305 creates a function topology for each of the functions 2 to 5 based on the information illustrated in FIG.

After step S3, the functional topology calculation unit 304 executes a route calculation process (step S4) giving priority to the functional topology. Hereinafter, the process of step S4 will be described.

Every packet is sent and received on the network. Even if a functional topology that focuses on a specific function is created, as described with reference to FIGS. 1 and 8, OFSs 102 that are nodes of the functional topology may not be physically connected to each other. . Therefore, an appropriate path cannot be formed only by the OFS 102 that is a node of the functional topology. Therefore, in step S4, based on the functional topology, the functional topology calculation unit 304 sets the OFS 102 having the function corresponding to the functional topology as a node on the transfer path and connects the OFSs 102 having the function to each other. If not, the OFS 102 that does not have the function is regarded as a node that holds between the OFSs 102 that have the function, and is included in the nodes on the transfer path to calculate the packet transfer path. . The function topology calculation unit 304 calculates a packet transfer path for each function. In this way, the functional topology calculation unit 304 determines the packet transfer path connecting the hosts 103 (see FIG. 1) for each function based on the functional topology for each function stored in the functional topology management unit 305. calculate.

FIG. 9 shows an example of a packet transfer path connecting the hosts 103 calculated for each function. FIG. 9 illustrates transfer paths corresponding to functions 1 to 5, respectively.

Since the appropriate path cannot be formed only by the OFS 102-1 and OFS 102-6 that are the nodes of the function 1 function topology, the function topology calculation unit 304 replaces the OFS 102-2 and OFS 102-5 that do not have the function 1 with the OFS 102. -1 and OFS 102-6, a packet transfer path between the host 103-1 and the host 103-2 is determined. Therefore, OFS 102-2 and OFS 102-5 that do not have function 1 also form a transfer path corresponding to function 1 (see FIG. 9). The OFS 102-2 that does not have the function 1 simply transfers the packet received from the OFS 102-1 to the OFS 102-6, and does not perform any processing related to the function 1. The same applies to OFS102-5.

That is, when the function topology calculation unit 304 calculates a transfer path related to the function of interest, if the transfer path cannot be calculated only by the OFS 102 that has the function, the function topology calculation unit 304 also passes through the OFS 102 that does not have the function. The transfer route is calculated by permitting the above.

As described above, by considering the OFS 102-2 and OFS 102-5 that do not have the function 1 as the nodes that have the function 1 between the OFS 102-1 and the OFS 102-6, the function topology calculation unit 304 Forms a transfer path corresponding to function 1 (see FIG. 9). Similarly, the function topology calculation unit 304 calculates a transfer path corresponding to each of the functions 2 to 5 as a packet transfer path between the host 103-1 and the host 103-2 (see FIG. 9).

After step S4, the update instruction unit 306 executes a flow table update process (step S5). In step S <b> 5, the update instruction unit 306 transmits a flow table update instruction to each OFS 102 on the transfer path so that the packet is transferred along the transfer path calculated by the functional topology calculation unit 304. The OFS 102 updates the flow table according to the update instruction from the update instruction unit 306. As a result, the packet transmitted from the transmission source host is transferred to the next OFS 102 in accordance with the flow table in each OFS 102 on the transfer path, and reaches the transmission destination host. In this way, a transfer path corresponding to the function calculated by the function topology calculating unit 304 is constructed. In step S5, for example, the update instruction unit 306 transmits a flow table update instruction to each OFS 102 on the transfer path for each transfer path corresponding to each function.

By the operations in steps S1 to S5 as described above, an appropriate route centering on the high-function OFS 102 that can handle each function can be constructed between the host 103-1 and the host 103-2.

Hereinafter, the present invention will be described using more specific examples. In the following description, the OFC 101 calculates a transfer path for each function in advance for each combination of a transmission source host and a transmission destination host, and forwards a packet along the transfer path to a node on each transfer path. As an example, the flow table is instructed to be updated.

FIG. 10 is a schematic diagram showing an example of a network configuration. Hereinafter, the network configuration shown in FIG. 10 will be described as an example. As already described, the number of OFSs 102 and hosts 103 is arbitrary. The example illustrated in FIG. 10 illustrates a network configuration in which the number of OFSs 102 is nine and the number of hosts 103 is six. Although not shown in FIG. 10, the OFC 101 having the configuration shown in FIG. 2 is provided similarly to the case shown in FIG.

In addition, there is a difference in the installed functions of each OFS 102 from OFS 102-1 to OFS 102-9. FIG. 11 is an explanatory diagram showing the difference in the installed functions of each OFS 102 shown in FIG.

The OFC 101 (not shown in FIG. 10) executes the processes of steps S1 to S6 described above. Hereinafter, the process progress in this example will be described.

First, after the OFSs 102 are connected to form a network having the physical topology shown in FIG. 10, the OFC 101 executes an OFS-OFC connection process (step S1) for each OFS 102. The details of step S1 are as described in steps S21 to S28 (see FIG. 6), and a description thereof is omitted here.

By executing step S1 for each OFS 102, the OFS management unit 301 (see FIG. 2) of the OFC 101 acquires information on the function of the OFS 102 from each OFS 102. The OFS management unit 301 grasps the function possessed by each OFS 102 based on the information. Then, the OFS management unit 301 generates information indicating whether each OFS 102 has a function for each function, and stores the information in the OFS possessed function management unit 302 (step S2). In this example, the information shown in FIG. 11 is stored in the OFS possessed function management unit 302.

Subsequently, the functional topology calculation unit 304 executes a functional topology creation process (step S3). In step S3, the functional topology calculation unit 304 creates a functional topology for each function held by the OFS 102-1 to OFS 102-9. In this example, the functional topology calculation unit 304 creates a functional topology for each function 1 to 5 (see FIG. 11). FIG. 12 is a schematic diagram showing a functional topology corresponding to each of the functions 1 to 5 in this example. In the example illustrated in FIG. 12, in each functional topology, the OFS 102 that is a node of the functional topology is indicated by a solid line. Further, OFS 102 that is not included in the functional topology (OFS 102 that does not become a node of the functional topology) is indicated by a broken line.

The functional topology calculation unit 304 stores the functional topology created for each function in the functional topology management unit 305.

Next, the functional topology calculation unit 304 executes a route calculation process (step S4) giving priority to the functional topology. Hereinafter, step S4 in this example will be described.

The functional topology calculation unit 304 needs to construct a packet transfer path giving priority to the functional topology between the transmission source host and the transmission destination host. As described above, the functional topology calculation unit 304 calculates a packet transfer path based on the functional topology for each function. Here, in each of the functions 1 to 5, the number of OFSs 102 that need to have the function may differ on the transfer path from the transmission source host to the transmission destination host.

For example, in the case of a function for acquiring statistical information such as the number and size of packets that have passed on the transfer path, it is not necessary for all OFSs 102 on the transfer path from the transmission source host to the transmission destination host to have this function. This is because the number and size of packets passing through the OFS 102 on the transfer path are the same, and it is not necessary to acquire statistical information of the same packet in each OFS 102. In other words, in the case of a function for acquiring packet statistical information, if there is one OFS 102 having the function on the transfer path from the transmission source host to the transmission destination host, the packet statistical information can be acquired. it can.

Also, the case of IPv6 function will be explained. The OFS 102 having the IPv6 function can interpret the destination address recorded as an IPv6 address in the received packet. However, the OFS 102 that does not have the IPv6 function cannot interpret the destination address in the packet recorded with the IPv6 address. Here, in the open flow, the OFS 102 refers to the destination information in the received packet and searches for a corresponding flow entry from the flow table held in the OFS 102. The flow entry is information that defines a process for a packet (from which port to output, etc.) for each flow. It can be said that the flow table is a set of flow entries. FIG. 13 is an explanatory diagram showing the contents of the flow table. Each flow entry in the flow table describes a header “Fields” that identifies a packet and an action that defines a process for the received packet. The OFS 102 determines whether or not an action for the received packet is defined in the flow table, and if so, determines a next transfer destination of the received packet according to the action. Since the OFS 102 that does not have the IPv6 function cannot interpret the destination address in the packet recorded with the IPv6 address, the Action for the packet cannot be specified from the flow table, and the next transfer destination is determined. Can not do it. Even if the header field of the flow entry contains not the IPv6 address but the MAC (Media Access Control) address of the destination host that can be interpreted without possessing the IPv6 function, it is sent to the received packet. If the MAC address of the destination host is not included, the OFS 102 cannot interpret the IPv6 address itself. For this reason, the OFS 102 cannot acquire the MAC address of the destination host corresponding to the IPv6 address by using Neighbor Discovery Protocol (hereinafter referred to as NDP) such as ARP (Address Resolution Protocol) in IPv4. Then, the OFS 102 cannot specify the next transfer destination from the flow table.

In such a case, it is conceivable that the OFS 102 that does not have the IPv6 function inquires of the OFC 101 about the next transfer destination of the packet by transferring to the OFC 101 a packet for which the transfer destination is determined to be unknown. Thus, a packet that is determined to have an unknown transfer destination and is transferred to the OFC 101 is referred to as a first packet. Upon receiving the first packet, the OFC 101 analyzes the packet destination information and calculates a packet transfer path so that the packet reaches the destination host 103. After that, the OFC 101 gives an instruction to add a flow entry including Header Fields including the MAC address of the transmission destination host 103 and Action defining the transfer destination along the transfer route for each OFS 102 on the calculated transfer route. . Further, the OFC 101 writes the MAC address of the transmission destination host 103 in the received first packet, and returns the first packet to the OFS 102. As a result, each OFS 102 on the transfer path can search for an action of the corresponding flow entry based on the MAC address in the packet, and can determine the next transfer destination. In other words, when the OFS 102 that does not have the IPv6 function receives a packet whose destination can be specified only by an IPv6 address, the OFS 102 always forwards the packet to the OFC 101 as a first packet, and the OFC 101 performs the above processing. . When there are many OFSs 102 that do not have an IPv6 function in the network, each of those OFSs 102 makes an inquiry to the OFC 101 every time a packet whose destination can be specified only by an IPv6 address is received. The response waiting time from the OFC 101 is extra than that of the owned OFS 102. This may cause a data transfer delay.

However, it is assumed that a packet whose destination can be specified only by an IPv6 address passes through the OFS 102 having the IPv6 function. The OFS 102 can obtain the MAC address from the destination address recorded as an IPv6 address in the packet by using NDP. Then, when the OFS 102 writes the MAC address in the packet, the subsequent OFS 102 on the transfer path refers to the MAC address regardless of whether or not it has the IPv6 function, and You can search for Action and determine the next forwarding destination.

In other words, in order to enable the IPv6 function on the route from the transmission source host 103 to the transmission destination host 103, the OFS 102 serving as a switch (edge switch) that receives a packet from the transmission source host 103 has the IPv6 function. If you do.

As described with reference to the function for acquiring statistical information and the IPv6 function, the number of OFSs 102 that need to have a function on the transfer route and the transfer route on which the OFS 102 that has the function should be placed The location above varies from function to function. Further, whether or not it is necessary to always provide a function is different for each function. The functional topology calculation unit 304 calculates a transfer path for each function in consideration of the difference for each function.

In addition, since the functional topology is a diagram in which OFSs 102 having the focused function are connected as nodes, focusing on individual functions, the host 103 (see 10) is considered when creating the functional topology. Not. However, the packet transfer path is a path from the transmission source host 103 to the transmission destination host 103. Therefore, when calculating the transfer path, the function topology calculation unit 304 determines the feature of each function as described above (the number of OFSs 102 that need to have a function and the number of OFSs 102 that have the function. The transfer path is calculated in consideration of not only the position on the transfer path to be performed and whether or not it is necessary to always provide the function, but also the location of the host 103. Information for each function such as the number of OFSs 102 that need to have the function, the position on the transfer path where the OFS 102 that has the function should be placed, and whether or not it is necessary to always provide the function. Is hereinafter referred to as functional feature information. Functional feature information related to various functions is given to the functional topology calculation unit 304 in advance by a network administrator or the like, for example, and the functional topology calculation unit 304 holds functional feature information related to various functions. The functional topology calculation unit 304 may acquire the functional feature information by other methods. It can be said that the function characteristic information of a certain function indicates a condition that the transfer path corresponding to the function should satisfy.

FIG. 14 is a flowchart showing an example of processing progress of the functional topology calculation unit 304 in step S4. First, the functional topology calculation unit 304 identifies each combination of a transmission source host and a transmission destination host (step S31). FIG. 15 is an explanatory diagram illustrating an example of each combination of the transmission source host and the transmission destination host specified in step S31. In this example, in the network configuration shown in FIG. 10, the host 103-1, the host 103-3, and the host 103-5 correspond to the transmission source hosts, and the host 103-2, the host 103-4, and the host 103-6. Is assumed to correspond to the destination host.

Next, the functional topology calculation unit 304 identifies the functional feature information of the function possessed by each OFS 102 (step S32). For example, the function topology calculation unit 304 may extract the function feature information of the functions held by each OFS 102 from the function feature information of various functions given in advance. In this example, any of the OFS 102 shown in FIG. 10 has functions 1 to 5 (see FIG. 11). Therefore, the function topology calculation unit 304 may extract the function feature information of the functions 1 to 5. FIG. 16 shows an example of function feature information of function 1 to function 5. In the following description, it is assumed that the function characteristic information shown in FIG.

For example, it is assumed that function 1 shown in FIG. 11 is a function for acquiring statistical information such as the number and size of packets that have passed through the transfer path. As described above, only one OFS 102 having a function of acquiring statistical information is required on the transfer path. Further, the OFS 102 having the function of acquiring statistical information need not be limited to an edge switch, a core switch, or the like. That is, if any transfer path calculated for each combination of the transmission source host and the transmission destination host always passes through at least one OFS 102 having the function 1, function 1 (statistical information acquisition function) ) Is effective. Also, as shown in FIG. 16, function 1 is a function that should always be provided. Therefore, the transfer path corresponding to other functions (functions 2 to 5) calculated by each combination of the transmission source host and the transmission destination host also passes through either the OFS 102-1 or OFS 102-6 that has the function 1. There is a need to.

In addition, the function characteristic information of function 3 shown in FIG. 16 indicates that “edge priority” is given regarding the arrangement. This means that it is necessary to construct a transfer path in which the OFS 102 having the function 3 is arranged as close to the transmission source host 103 as possible. For example, it is assumed that the transmission source host is the host 103-5 (see FIG. 10). OFSs 102-4 and OFS102-9 that have function 3 in the vicinity of the host 103-5 include OFS102-4 and OFS102-9 (see FIGS. 10 and 11). Since the function feature information of function 3 defines “edge priority” with respect to the arrangement, it is necessary to construct a transfer path from the host 103-5 to the OFS 102-4 via the OFS 102-7. .

After step S32, the functional topology calculation unit 304 calculates a transfer path for each function with respect to each combination of the transmission destination host and the transmission source host specified in step S31 (step S33). At this time, the functional topology calculation unit 304 calculates, based on the functional topology, a transfer route that minimizes the number of hops while satisfying the condition defined by the functional feature information for each function. When there is a function that is determined to be always provided, the function topology calculation unit 304 calculates a transfer path so as to satisfy the condition defined by the function feature information of the function.

For each combination of the destination host and source host, pay attention to the individual functions, satisfy the conditions defined by the functional feature information of the focused function, and determine the transfer route with the minimum number of hops. The results calculated based on the functional topology are shown in FIGS.

The transfer paths shown in FIGS. 17 to 20 are transfer paths calculated so as to satisfy the conditions defined by the function feature information of the function of interest. However, functional feature information other than the focused function is not considered. For this reason, in the transfer paths shown in FIGS. 17 to 20, there is a transfer path that does not pass through the OFS 102-1 or OFS 102-6 having the function 1 that is determined to be always provided. For example, no. The transfer path 72 (see FIG. 19) is a transfer path corresponding to the function 2 in which the host 103-3 is a transmission source and the host 103-6 is a transmission destination. This transfer path satisfies the conditions determined by the function feature information of function 2, but is determined without considering function feature information other than function 2. As a result, neither OFS 102-1 nor OFS 102-6 passes. No. 1 shown in FIG. With the transfer path 72, statistical information is not acquired when a packet that requires function 2 is transferred on the transfer path from the host 103-3 to the host 103-6. For this reason, the topology calculation unit 304 has the No. 1 shown in FIG. As in the case of the transfer path 72, the transfer path that does not pass through any of the OFS 102-1 and OFS 102-6 having the function 1 passes through either one of the OFS 102-1 and OFS 102-6. Recalculate the transfer path. The recalculation result of the transfer path is shown in FIGS.

As described above, when the transfer route is recalculated so as to pass through either one of the OFS 102-1 and OFS 102-6 having the function 1, the number of hops may increase. Then, there may be an increase in the number of transfer paths that satisfy the condition defined by the function feature information of the function of interest and the condition defined by the function feature information of the function determined to be always provided. The recalculated No. 75 transfer path (see FIG. 23) is No. before recalculation. In the 75 transfer paths (see FIG. 19), the OFS 102-6 is also routed. As a result, the number of hops increased from 3 to 4. When the number of hops is 4, the number of transfer paths that satisfy the condition defined by the function 4 of interest and the function characteristic information of the function 1 that should be always provided is increased by one. In FIG. It is shown as 75-2.

Also, No. 76, no. 77, no. The transfer path 78 (see FIG. 19) is a transfer path corresponding to the function 5 in which the host 103-3 is a transmission source and the host 103-6 is a transmission destination. No. The route 76 has already passed through OFS-1. No. 77, no. 78, since neither the OFS 102-1 nor the OFS 102-6 passes, re-calculation so that it passes through either one of the OFS 102-1 and OFS 102-6 is No. The number of hops will increase from 76. Therefore, as a result of recalculation, the transfer path corresponding to the function 5 in which the host 103-3 is the transmission source and the host 103-6 is the transmission destination is No. 76 (see FIG. 23). In FIG. 21 to FIG. 24, the transfer paths that are excluded as a result of recalculation are shown together with a strikethrough.

When a plurality of transfer routes corresponding to a certain function are obtained with a certain host as the transmission source and the certain host as the transmission destination, the functional topology calculation unit 304 selects the arbitrary one route from the transfer routes. The transfer path corresponding to the function may be narrowed down to one.

As a result of the above processing, the packet transfer path is determined for each combination of the source host, destination host, and function. The functional topology calculation unit 304 determines, for each determined transfer path, the condition of a packet to be transferred on the transfer path as Header Fields of the flow entry, and for each OFS 102 of the transfer path information, It is determined as Action that a packet is output from the port corresponding to the node.

After step S4, the update instruction unit 306 adds a flow entry including the Header Fields defined for the transfer path determined in step S4 and the Action defined for each OFS 102 on the transfer path to the flow table. An instruction to add is given to each OFS 102 on the transfer path (step S5). The update instruction unit 306 performs this operation for each transfer path calculated for each combination of the transmission source host, the transmission destination host, and the function. Upon receiving the instruction, the OFS 102 adds a flow entry to the flow table according to the instruction. As a result, a route determined for each combination of the transmission source host, the transmission destination host, and the function is constructed on the network shown in FIG.

In the above description, the OFC 101 calculates the transfer path for each function in advance for each combination of the transmission source host and the transmission destination host, and forwards the packet along the transfer path to the node on each transfer path. As an example, the flow table is instructed to be updated. In this case, before the transmission source host transmits the packet, the OFS 102 on the transfer path already has a flow entry corresponding to the transfer path for each transfer path according to the combination of the transmission source host, the destination host, and the function. Is set. Therefore, the number of times the OFC 101 receives the first packet can be reduced.

Also, instead of calculating all the transfer paths according to the combination of the source host, the destination host and the function in advance, when the OFC 101 receives the first packet, only the transfer path for transferring the first packet is used. May be calculated. Hereinafter, when the OFC 101 receives a first packet, an operation when only the transfer path for transferring the first packet is calculated will be described.

Even in this case, the OFC 101 performs steps S1 to S3 in advance. The operations in steps S1 to S3 are the same as the operations in steps S1 to S3 already described. When the OFC 101 receives the first packet, the OFC 101 performs step S4 (more specifically, steps S31 to S33 shown in FIG. 14).

However, in step S31, the functional topology calculation unit 304 need only determine the combination of the transmission source host and the transmission destination host indicated by the first packet. That is, only one combination of the transmission source host and the transmission destination host is determined.

The operation in step S32 is the same as the operation in step S32 already described.

Next, in step S33, the functional topology calculation unit 304 analyzes the first packet and specifies a function that can interpret the packet. The functional topology calculation unit 304 pays attention to only one combination of the transmission source host and the transmission destination host determined in step S31, and is a transfer path from the transmission source host to the transmission destination host. Calculate the corresponding transfer path. At this time, the functional topology calculation unit 304 calculates a transfer route that minimizes the number of hops while satisfying the condition defined by the functional feature information of the function specified based on the first packet. Furthermore, if there is a function that should always be provided, the transfer path is recalculated so as to satisfy the conditions defined by the function feature information of the function.

For example, assume that the transmission source of the first packet is the host 103-1, and the transmission destination is the host 103-4. Further, it is assumed that the function specified as the function capable of interpreting the first packet is the function 2. In this case, the function topology calculation unit 304 determines the No. corresponding to the transmission source host 103-1, the transmission destination host 103-4, and the function 2. 8 (see FIG. 17) may be calculated. In addition, No. The transfer path 8 is routed through the OFS 102-6 having the function 1 to be always provided. Therefore, in this example, no. There is no need to recalculate the 8 transfer paths.

The functional topology calculation unit 304 determines the condition of the packet to be transferred on the calculated transfer route as the header Fields of the flow entry, and for each OFS 102 of the transfer route information, sends a packet from the port corresponding to the next node on the route. Define the action to be output.

After step S4, the update instruction unit 306 adds a flow entry including the Header Fields defined for the transfer path determined in step S4 and the Action defined for each OFS 102 on the transfer path to the flow table. An instruction to add is given to each OFS 102 on the transfer path (step S5). Upon receiving the instruction, the OFS 102 adds a flow entry to the flow table according to the instruction. As a result, a packet transfer path having the same header field as the first packet is configured on the network shown in FIG. In addition, the update instruction unit 306 returns the first packet to the OFS 102 that has transmitted the first packet to the OFC 101. The OFS 102 transfers the packet according to the added flow entry. Thereafter, the packet is transferred to the destination host along the established transfer path. The same applies to a packet having the same header field as the first packet.

As described above, when the OFC 101 calculates the transfer path in response to the reception of the first packet, the transfer path may be calculated for the combination of the source host, the destination host, and the function determined from the first packet. Therefore, the processing load when calculating the transfer path can be reduced.

Further, when the OFS 102 is newly added, the OFC 101 may perform steps S1 to S5. In this case, the functional topology calculation unit 304 recreates the functional topology with the addition of the OFS 102. As a result, it is possible to calculate the packet transfer path so that the function possessed by the newly added OFS 102 can be provided as the entire network.

According to the present invention, when the function topology calculation unit 304 calculates a transfer path related to a function of interest, the function topology calculation unit 304 passes not only the OFS 102 that has the function but also the OFS 102 that does not have the function. Is also permitted to calculate the transfer route. For example, the OFS 102 that does not have a function is used as a node that handles between the OFSs 102 that have a function. Therefore, it is possible to calculate an appropriate transfer path, not a detoured transfer path that passes only through a functioning OFS.

Further, according to the present invention, a transfer route corresponding to a function is calculated based on the function topology. For this reason, the OFS 102 having the function is included in the transfer path corresponding to the function. In addition, the transfer path is calculated so that the OFS 102 having the function to be always provided is included in the transfer path. Therefore, necessary functions can be provided as the entire network. Compared with the general technique, in the general technique, the packet transfer path is calculated based on the information on the transmission source and transmission destination of the packet, but there is no concept of using a functional topology. Therefore, for example, there are cases where a transfer route that can acquire statistical information is calculated and cases where a transfer route that cannot acquire statistical information is calculated. In order to avoid such a situation, the version of OpenFlow protocol was lowered in accordance with the function of other OFS, or a part of the vendor's original function was turned off. In the present invention, it is not necessary to do such a thing, and necessary functions can be provided as the entire network.

Thus, according to the present invention, even if there is a difference in function between the OFSs 102 included in the network, an appropriate packet transfer path can be determined while making use of the function.

Further, according to the present invention, the function topology calculation unit 304 calculates the function topology for each function possessed by each OFS 102 existing in the network, and then the packet transfer path corresponding to the function based on the function topology. Is calculated. As a result, for example, the network administrator can grasp that the physical connection connecting the OFSs 102 is employed more than the transfer path corresponding to the function. Therefore, the network administrator can predict the occurrence of the network load in advance, and the countermeasures can be examined in advance.

Furthermore, regarding the avoidance of the network load, it is also possible that the network load may be avoided if the OFS 102 having only a specific function is added to the network instead of the OFS 102 having all functions. It is mentioned as an effect. In other words, by adding the OFS 102 having only a specific function to the network, the function topology of the function can be changed. Therefore, the packet transfer route calculated based on the function topology is also changed. be able to. As a result, the load on the network can be avoided.

Embodiment 2. FIG.
FIG. 25 is a block diagram showing a configuration example of the OFC 101 in the second embodiment of the present invention. The same elements as those of the OFC 101 in the first embodiment are denoted by the same reference numerals as those in FIG. Further, the OFS 102 and the host 103 (not shown in FIG. 25) in the second embodiment are the same as the OFS 102 and the host 103 (see FIGS. 1 and 10) in the first embodiment, and the description thereof is omitted.

The OFC 101 in the second embodiment further includes a function topology display control unit 309 in addition to the components of the OFC 101 in the first embodiment. The functional topology display control unit 309 displays the functional topology of each function stored in the functional topology management unit 305 on a display device (not shown).

By displaying the functional topology, the network administrator can visually confirm each functional topology. Therefore, based on the displayed functional topology, the network administrator can understand what function the OFS 102 possessing is added to where the functional topology changes and a more appropriate transfer path can be constructed for the network. can do. In particular, as the number of OFSs 102 existing in the network increases, the network load is predicted only by information indicating the functions possessed by the OFS 102 (information stored in the OFS possessed function management unit 302 as illustrated in FIG. 7). Becomes more difficult. Even in such a case, the functional topology display control unit 309 displays the functional topology on the display device, so that the functional topology can be visually presented to the network administrator. As a result, network management for the network administrator becomes easier.

The functional topology display control unit 309 is realized by a CPU of a computer that operates according to a path control program, for example. Further, the functional topology display control unit 309 may be realized by hardware different from other components.

Next, the minimum configuration of the present invention will be described. FIG. 26 is a block diagram showing an example of the minimum configuration of the present invention. The path control device of the present invention includes a transfer path calculation unit 92 and a setting unit 93.

The transfer route calculation unit 92 (for example, the functional topology calculation unit 304 that executes Step S4) calculates a transfer route including a packet transfer device having a function for a packet.

The setting unit 93 (for example, the update instruction unit 306) performs setting so that each packet transfer device on the transfer path calculated by the transfer path calculation unit 92 transfers the packet along the transfer path.

With such a configuration, even when there is a difference in function between packet transfer apparatuses included in the network, an appropriate packet transfer route can be determined while making use of the function.

A topology in which packet transfer apparatuses having the same function are connected to each other based on information indicating whether or not each packet transfer apparatus has a function for each function of the packet transfer apparatus (for example, OFS102). A functional topology creating unit (for example, a functional topology calculating unit 304 that executes step S3) for creating a functional topology for each function is provided, and the transfer path calculating unit 92 corresponds to the function of the packet transfer apparatus based on the functional topology. When calculating the transfer path of a packet, when calculating the transfer path, not only the packet transfer apparatus indicated in the functional topology but also the packet transfer apparatus that does not have a function corresponding to the functional topology May be configured to calculate the transfer path.

The transfer path calculation unit 92 specifies all combinations of the packet transmission source and the transmission destination, calculates the transfer path based on the functional topology for each function for each combination of the packet transmission source and the transmission destination, The setting means 93 causes each packet transfer device on the transfer path to transfer the packet along the transfer path for each transfer path calculated for each combination of the packet source, destination, and function. A configuration for performing the setting may be used.

When the transfer path calculation unit 92 receives a packet (for example, a first packet) from which the packet transfer apparatus cannot specify the transfer destination from the packet transfer apparatus, the transfer path calculation unit 92 specifies the combination of the transmission source and the transmission destination of the packet, For the combination of the source and destination of the packet, the transfer path is calculated based on the function topology of the function, and the setting means 93 for each packet transfer device on the transfer path Thus, the configuration may be such that the packet is transferred along the transfer path.

The transfer path corresponding to the function so that the transfer path calculating unit 92 satisfies the condition (for example, the condition indicated by the function characteristic information) determined for each function as the condition to be satisfied by the transfer path corresponding to the function of the packet transfer apparatus. May be configured to calculate.

When the transfer path calculation unit 92 calculates a transfer path corresponding to a function, if there is a function that should be always provided separately from the function, the transfer path calculation unit 92 should always be provided along with the conditions defined for the function. The configuration may be such that the transfer path corresponding to the function is calculated so as to satisfy the condition defined for the function.

It may be configured to include display control means (for example, the functional topology display control unit 309) that causes the display device to display the functional topology created by the functional topology creation means.

The functional topology creating means may be configured to recreate the functional topology when a new packet transfer device is added.

The present invention has been described above with reference to the embodiments, but the present invention is not limited to the above-described embodiments. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

This application claims priority based on Japanese Patent Application No. 2014-045294 filed on March 7, 2014, the entire disclosure of which is incorporated herein.

Industrial applicability

The present invention is preferably applied to a route control device that controls a transfer route of a packet passing through the packet transfer device.

101 OFC
102 OFS
DESCRIPTION OF SYMBOLS 103 Host 301 OFS management part 302 OFS possession function management part 304 Function topology calculation part 305 Function topology management part 306 Update instruction part 307 Connection processing part 309 Function topology display control part

Claims (10)

A route control device for controlling a transfer route of a packet passing through a packet transfer device,
A transfer route calculating means for calculating a transfer route including a packet transfer device having a function for a packet;
A path control device comprising: a setting unit configured to perform a setting to transfer a packet along the transfer route to each packet transfer device on the transfer route calculated by the transfer route calculating unit. For each function of the packet transfer device, a function topology that is a topology in which packet transfer devices having the same function are connected to each other based on information indicating whether or not each packet transfer device has a function. With functional topology creation means to create
Transfer route calculation means
Based on the functional topology, the packet transfer path corresponding to the function of the packet transfer apparatus is calculated, and when calculating the transfer path, not only the packet transfer apparatus indicated in the function topology but also the function topology is supported. The route control device according to claim 1, wherein a packet transfer device that does not have a function to perform is permitted to pass through and a transfer route is calculated. Transfer route calculation means
Identify all packet source and destination combinations,
For each combination of packet source and destination, calculate the forwarding path based on the functional topology for each function,
Setting means
For each transfer path calculated for each combination of a packet transmission source, a transmission destination, and a function, a setting is made for each packet transfer apparatus on the transfer path to transfer the packet along the transfer path. Item 3. The path control device according to Item 2. Transfer route calculation means
When a packet transfer apparatus receives a packet from which the transfer destination cannot be specified from the packet transfer apparatus, it specifies a combination of a transmission source and a transmission destination of the packet, specifies a function capable of interpreting the packet,
For the combination of the source and destination of the packet, calculate the transfer path based on the functional topology of the function,
Setting means
The path control device according to claim 2, wherein each packet transfer device on the transfer route is set to transfer a packet along the transfer route. Transfer route calculation means
5. The transfer path corresponding to the function is calculated so that the transfer path corresponding to the function of the packet transfer apparatus satisfies a condition defined for each function as a condition to be satisfied. 5. The routing control device according to 1. Transfer route calculation means
When calculating a transfer route corresponding to a function, if there is a function that should be always provided separately from the function, a condition defined for the function to be always provided along with the condition defined for the function The path control device according to claim 5, wherein a transfer path corresponding to the function is calculated so as to satisfy. The path control device according to any one of claims 2 to 6, further comprising display control means for causing the display device to display the functional topology created by the functional topology creation means. The route control device according to any one of claims 2 to 7, wherein the functional topology creating means recreates the functional topology when a new packet transfer device is added. A route control method for controlling a transfer route of a packet passing through a packet transfer device,
Calculate the transfer path including the packet transfer device that has the function for the packet,
A route control method comprising: setting each packet transfer device on the transfer route to transfer a packet along the transfer route. A route control program installed in a computer for controlling a transfer route of a packet passing through a packet transfer device,
In the computer,
A transfer route calculation process for calculating a transfer route including a packet transfer device having a function for a packet, and
A path control program for causing a packet transfer device on a transfer path calculated in the transfer path calculation process to execute a setting process for setting a packet to be transferred along the transfer path.

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