JP6894408B2 - Linked virtual network allocation method and equipment - Google Patents

Description

The present invention relates to a method and an apparatus for allocating a cooperative virtual network to a base network, and more particularly to a method and an apparatus for allocating a cooperative virtual network that shares a base node having a service cooperation function to the base network.

In Non-Patent Document 1, the graph representing the infrastructure network is expanded by connecting each virtual node and all the infrastructure nodes to which the virtual node can be assigned by using an expansion link, and the graph on the expansion graph is expanded. A method of realizing the allocation of a virtual network to an underlying network using a mathematical programming model is disclosed.

In Non-Patent Document 2, a virtual node adjacent to a virtual node already assigned to a base node can be assigned to a base path having a maximum base path length or less given in advance by a newly assigned virtual link. A method of sequentially allocating to the base node is disclosed.

In Patent Documents 1 and 2, the graph representing the infrastructure network is expanded by connecting each virtual node and all the infrastructure nodes to which the virtual node can be assigned by using an expansion link, and the graph representing the infrastructure network is expanded on this expanded graph. Discloses a method of determining the base path to which the virtual link is assigned and the allocation of the virtual node to which the virtual link is connected to the base node by sequentially allocating each virtual link to the minimum cost route.

Japanese Patent No. 6279427 Japanese Patent No. 6307377

M. Chowdhury, MR Rahman, and R. Boutaba, "ViNEYard: Virtual network embedding algorithms with coordinated node and link mapping," IEEE / ACM Trans. On Networking, vol. 20, no. 1, pp. 206-219, Feb . 2012. J. Lischka and H. Karl, "A virtual network mapping algorithm based on subgraph isomorphism detection," in Proc. ACM VISA '09, August 2009.

In Non-Patent Document 1, the amount of calculation increases due to the use of the mathematical planning model, and it cannot be applied to the allocation of the virtual network to the large-scale infrastructure network. In Non-Patent Document 2, efficient virtual network allocation may not be realized depending on the order of virtual nodes sequentially assigned to the base nodes.

In Patent Documents 1 and 2, efficient virtual network allocation may not be realized depending on the order of virtual links assigned to the minimum cost route.

An object of the present invention is a collaborative type that solves the above technical problems and makes the form of the collaborative virtual network configured on the infrastructure network closer to the form in which the original collaborative virtual network is expanded to the minimum and evenly. To provide a virtual network allocation method and equipment.

In order to achieve the above object, the present invention relates to a virtual network allocation method and device for allocating a virtual network composed of a group of virtual nodes including a normal virtual node to a base network composed of a group of infrastructure nodes. It is characterized by having the above configuration.

(1) Select the normal virtual node to be assigned to the base node, select the allocation destination candidate of the selected normal virtual node from the base node group that is the allocation destination candidate, and have already been assigned to the selected normal virtual node and the base node. Calculate the distance vdistance on the virtual network with each virtual node of, calculate the distance sdistance on the base network between the base node of the allocation destination candidate and each base node to which the virtual node has been assigned, and correspond. When the distance ratio between sdistance and vdistance falls below a predetermined reference value, the selected normal virtual node is assigned to the base node of the current allocation destination candidate.

(2) The virtual network includes a cooperative virtual node as a virtual node, the infrastructure network includes a shared infrastructure node as an infrastructure node, and each normal virtual node is assigned to any infrastructure node before each cooperation virtual node. Is now assigned to one of the shared infrastructure nodes.

(3) The distance vdistance between virtual nodes on the virtual network is defined so that the larger the required capacity of the virtual node as the starting point, the shorter the distance, and the larger the required bandwidth of the virtual path connecting the virtual nodes, the shorter the distance. ..

(4) The distance sdistance between the base nodes on the base network is defined so that the larger the free space of the base node as the starting point, the shorter the distance, and the larger the free bandwidth of the base path connecting the base nodes, the shorter the distance. ..

According to the present invention, the following effects are achieved.

(1) Since the shape of the collaborative virtual network configured on the infrastructure network approaches the shape of the original collaborative virtual network evenly expanded at the minimum ratio according to the arrangement of the shared infrastructure nodes, the infrastructure Linked virtual network allocation with good resource utilization efficiency can be realized.

(2) By using the allocation result of the linked virtual node group to the shared infrastructure node group, it is possible to allocate from the first normal virtual node to the infrastructure node with high accuracy.

(3) Since it is possible to equalize the free space of the base node and the free bandwidth of the base link after allocating the cooperative virtual network, more cooperative virtual networks can be allocated to the base network.

(4) Since the virtual link with a large required bandwidth is assigned to the relatively short base path, the total base link bandwidth required for allocating the cooperative virtual network can be reduced.

It is a figure (the 1) which shows typically the method of allocating the cooperative virtual network VN to the base network SN. It is a figure (2) which shows typically the method of allocating the cooperative virtual network VN to the base network SN. It is a conceptual diagram of the cooperative virtual network allocation method by this invention. It is a flowchart which showed the procedure of the allocation processing to the base network of the cooperative virtual network which concerns on one Embodiment of this invention. It is a flowchart which showed the procedure of the allocation process to the base node of a normal virtual node. It is a flowchart which showed the procedure of the allocation process to the shared base node of a cooperation virtual node. It is a functional block diagram which showed the structure of the main part of the virtual network allocation apparatus which concerns on one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIGS. 1 and 2 are diagrams schematically showing a method of allocating a linked virtual network VN including a linked virtual node group to a base network SN including a shared platform node group having a service linkage function.

As shown in Fig. 1, the linked virtual network VN includes the linked virtual nodes vn (vn1, vn3) indicated by hatching (●) and the normal virtual nodes vn (vn2, vn4) indicated by white circles (○). Is concatenated with a virtual link vl. The infrastructure network SN is configured by connecting the shared infrastructure node sn (●) indicated by hatching and the other normal infrastructure nodes sn (○) with an infrastructure link.

The linked virtual node vn (group) of the linked virtual network VN and the shared platform node sn (group) of the platform network SN are specified in advance. A server (not shown) that manages data shared by each cooperative virtual network VN is connected to the shared infrastructure node sn.

The required capacity of each linked virtual node vn of the linked virtual network VN and each normal virtual node vn (hereinafter, may be collectively referred to as "virtual node") and the required bandwidth of each virtual link vl are specified in advance. As the index of the required capacity, for example, the required capacity and the required operating rate of the resources (memory, CPU, disk recording medium, etc.) of the computers constituting the virtual node can be used. Each virtual node vn is assigned to one different base node sn.

In the present embodiment, each cooperative virtual node vn is assigned to one different shared infrastructure node sn, and each normal virtual node vn is assigned to one different infrastructure node sn. In the example of FIG. 2, the linked virtual nodes vn1 and vn3 are assigned to the shared infrastructure nodes sn6 and sn3, respectively, and the normal virtual nodes vn2 and vn4 are assigned to the infrastructure nodes sn1 and sn7, respectively.

Each virtual link vl of the cooperative virtual network VN is assigned to one base path connecting between the base nodes sn to which the virtual nodes vn connected to both ends of the virtual link vl are assigned. In the example of FIG. 2, the virtual link vl4 that normally connects the virtual nodes vn3 and vn4 is assigned to the base path passing through the base nodes sn3, sn8, and sn7.

Allocation of each virtual node vn and virtual link vl cannot exceed the free space of the base node sn and the free bandwidth of each base link that constitutes the base path. For example, the virtual link vl4 cannot be allocated beyond the free bandwidth of the base link between the base nodes sn3 and sn8 and the base link between the base nodes sn8 and sn7. As the index of the free space, for example, the free capacity and the free utilization rate of the resources (memory, CPU, disk recording medium, etc.) of the computers constituting the base node can be used.

In the present embodiment, the allocation of the cooperative virtual node vn group to the shared infrastructure node group sn is set as the first reference point, and the distance between the infrastructure nodes to which the virtual nodes on the infrastructure network SN are assigned and the cooperation virtual network VN Each virtual node is sequentially assigned to each base node so that the ratio with the distance between the virtual nodes is the minimum and uniform. As a result, the shape of the collaborative virtual network VN configured on the infrastructure network SN can be brought closer to a similar shape in which the original collaborative virtual network is evenly expanded at the minimum ratio according to the arrangement of the shared infrastructure nodes. Can be done.

FIG. 3 is a conceptual diagram of the cooperative virtual network allocation method according to the present invention. Here, from the state in which the linked virtual nodes vn1 and vn2 are pre-allocated to the shared infrastructure nodes sn1 and sn2, respectively, the normal virtual node vn3 is first assigned to the infrastructure node sn3, and then the allocation destination of the normal virtual node vn4. The case of determining the base node to be used will be described.

If the base node sn4 is one of the allocation destination candidates of the normal virtual node vn4, let's allocate the distance on the base network SN from the base node sn4 of the allocation destination candidate to the base node sn1 to which the virtual node vn1 is allocated. Find the ratio R1 to the distance on the cooperative virtual network VN from the virtual node vn4 to the virtual node vn1.

Next, the ratio R2 between the distance on the base network from the base node sn4 of the candidate allocation destination to the base node sn2 to which the other virtual node vn2 has been assigned and the distance from the virtual node vn4 to the virtual node vn2 is obtained.

Further, the ratio R3 of the distance on the base network from the base node sn4 of the candidate allocation destination to the base node sn3 to which the other virtual node vn3 has been assigned and the distance from the virtual node vn4 to the virtual node vn3 is obtained.

Then, if these ratios R1, R2, and R3 can be recognized as the minimum and equal, the virtual node vn4 is actually assigned to the base node sn4 of the allocation destination candidate and assigned, and this is assigned to all the virtual nodes of the cooperative virtual network VN. Repeat for vn.

FIG. 4 is a flowchart showing a procedure of allocation processing of the cooperative virtual network VN to the base network SN according to the embodiment of the present invention.

In step S1, all the linked virtual nodes vn of the virtual network VN are assigned to the shared infrastructure nodes that satisfy the predetermined conditions of the infrastructure network SN. The allocation method will be described in detail later with reference to the flowchart of FIG.

In step S2, one of the normal virtual nodes vn is usually selected in descending order of the requested capacity. In step S3, the selected normal virtual node vn is assigned to one of the unassigned underlying nodes sn. The allocation method will also be described in detail later with reference to the flowchart of FIG.

In step S4, it is determined whether or not there is an unselected normal virtual node vn. The process returns to step S2 until the unselected normal virtual node vn disappears, the next normal virtual node vn is selected in descending order of the required capacity, and each of the above processes is repeated. When the allocation to the base node sn for all the normal virtual nodes vn is completed, the process proceeds to step S5.

In step S5, one of the virtual links vl is sequentially selected in descending order of the requested band. In step S6, the selected virtual link vl is assigned to the base path of the base network SN. Each virtual link vl is assigned to the shortest base path in which all the base links connecting the base nodes sn to which the virtual nodes vn at both ends are assigned have a free bandwidth equal to or higher than the required bandwidth.

In step S7, it is determined whether or not there is an unselected virtual link, and the process returns to step S5 and each of the above processes is repeated until there are no unselected virtual links vl. For all virtual links vl, the process ends when the allocation to the base path is completed.

FIG. 5 is a flowchart showing a procedure for allocating the normal virtual node vn to the base node sn, which is carried out in step S3 of FIG. In the present embodiment, the base node to which the virtual node has not been allocated yet and has a free space equal to or larger than the required capacity of the normal virtual node vn to be allocated is a candidate for the allocation destination.

In step S301, the initial value is set in the variable margin. The variable margin is the allowable upper limit of the distance ratio between the base path on the base network SN corresponding to each virtual link vl of the virtual network VN and the distance ratio of the virtual link vl, and is the allocation part on the base network to which the virtual network VN is assigned. Is set to a value that makes the network topology of the virtual network VN closer to the similarity with a smaller similarity ratio to the topology of the virtual network VN.

In step S302, all the base nodes sn that have not yet been assigned a virtual node and have a free space equal to or greater than the required capacity of the selected normal virtual node vn are a set of candidates for allocation of the normal virtual node vn. It is said that. In step S303, one base node sn of the current allocation destination candidate is taken out from the allocation destination candidate set in descending order of free capacity.

In step S304, one of the combinations (virtual / base node pair) of the allocated virtual node vn'and the base node sn'is selected. In step S305, the distance vdistance on the virtual network VN from the selected normal virtual node vn to the virtual node vn'of the virtual / base node pair is calculated, and further, from the extracted base node sn of the allocation destination candidate. The distance sdistance on the base network SN to the base node sn'of the virtual / base node pair is calculated.

In step S306, the distance ratio (sdistance / vdistance) is compared with the variable margin based on the following equation (1).

If the above equation (1) is satisfied, the process proceeds to step S307, and it is determined whether or not there is an unselected virtual / base node pair for which the distance ratio comparison has not been completed yet. As long as there is an unselected virtual / base node pair, the process returns to step S304, and the distance calculation in step S305 and the determination in step S306 are repeated while switching the selected virtual / base node pair.

If the distance ratio is less than or equal to the variable margin in relation to all virtual / base node pairs, the allocation is judged to be valid and the process proceeds to step S308, and the selected normal virtual node is taken out. It is assigned to the base node of the candidate for the allocation destination this time and is considered to have been allocated.

On the other hand, if there is even one virtual / base node pair that does not satisfy the above equation (1), it is determined that this allocation is not valid, and the process proceeds to step S309. In step S309, it is determined whether or not the allocation destination candidate set configured in step S302 is empty. Unless it is empty, the process returns to step S303, the base node having the next largest free space is taken out as the next allocation destination candidate, and each of the above processes is repeated.

Further, when the allocation destination candidate set is empty, the process proceeds to step S310, the value of the variable margin is relaxed (increased in this embodiment), then the process returns to step S302, and after the allocation destination candidate set is reconstructed, the above Each process of is repeated.

According to the above allocation process, for all the normal virtual nodes vn, the distance on the base network between the allocation destination base node sn and the allocated base nodes of all virtual / base node pairs and the normal virtual node vn. The distance ratio between and the distance on the virtual network between all virtual / infrastructure node pairs and the corresponding assigned virtual nodes can be kept to a smaller constant value.

FIG. 6 is a flowchart showing the procedure of the allocation process of the linked virtual node to the shared infrastructure node, which is executed in step S1.

In step S101, the average distance on the infrastructure network SN to another shared infrastructure node sn is calculated for each shared infrastructure node sn. In step S102, each shared infrastructure node sn is sorted in ascending order of the average distance to other shared infrastructure nodes sn.

In step S103, the average distance on the linked virtual network VN to another linked virtual node vn is calculated for each linked virtual node vn. In step S104, each linked virtual node vn is sorted in ascending order of the average distance to the other linked virtual node vn.

In step S105, each cooperative virtual node vn is assigned to the shared infrastructure node sn having the same sort order.

In this embodiment, the distance sdistance between the base nodes on the base network SN is the reciprocal of the free space SCsn of the base node sn, which is the starting point, and the base node sn, which is the starting point, as shown in the following equation (2). It is obtained as the weighted sum with the shortest base path length SP leading to the base node sn'at the other end. The shortest base path length SP is defined as the sum of the reciprocals of the free bandwidth SB sl of each base link sl constituting the shortest base path.

As shown in the following equation (3), the distance vdistance between the virtual nodes on the virtual network is the reciprocal of the required capacity VCvn of the virtual node vn as the starting point and the virtual node at the other end from the virtual node vn as the starting point. It is calculated as the weighted sum with the shortest virtual path length VP leading to vn'. The shortest virtual path length VP is defined as the sum of the reciprocals of the required bandwidth VBvl of each virtual link vl constituting the shortest virtual path.

In the infrastructure network SN, the larger the free space of the infrastructure node sn and the free bandwidth of the infrastructure path, the shorter the distance, so the probability that a virtual node or virtual link will be assigned to such an infrastructure node or infrastructure path increases.

That is, the virtual node is preferentially assigned to the base node having a large free space when the value of the variable margin is small, and the probability that the virtual link is assigned as the shortest path to the base path having a large free bandwidth is high. As a result, it is possible to equalize the free space of the base node and the free bandwidth of the base link after allocating the cooperative virtual network.

On the other hand, in a virtual network, the larger the required capacity of the virtual node and the required bandwidth of the virtual path, the shorter the distance. Therefore, the linked virtual node with a large required capacity is assigned to the shared infrastructure node with a large free space, and the virtual link with a large required bandwidth is allocated to the relatively short infrastructure path.

As a result, it is possible to equalize the free space of the shared infrastructure node group after allocating the linked virtual node group. In addition, the total infrastructure link bandwidth required for allocating the cooperative virtual network can be reduced. Comparing the free space constraint on the base node and the free bandwidth constraint on the base link, if the former is strong, the weight value weight is close to 0.0, and if the latter is strong, the weight value weight is close to 1.0. It is possible to realize a collaborative virtual network allocation.

FIG. 7 is a functional block diagram showing a configuration of a main part of the virtual network allocation device according to the embodiment of the present invention. The virtual network allocation device of the present invention can be configured by implementing an application (program) that realizes each function on a general-purpose computer or server. Alternatively, it can be configured as a dedicated machine or a single-purpose machine in which a part of the application is made into hardware or ROM.

The topology information of the cooperative virtual network VN and the topology information of the infrastructure network SN are input to the virtual network allocation device 1. The topology information of the virtual network VN includes the required capacity of each virtual node vn, the required bandwidth of each virtual link vl, and information on whether each virtual node vn is a cooperative virtual node or a normal virtual node.

The topology information of the infrastructure network SN includes information on the free space of each infrastructure node sn, the free bandwidth of each infrastructure link, and whether each infrastructure node sn is a shared infrastructure node or a normal infrastructure node.

The node selection unit 10 includes a first selection unit 101 and a second selection unit 102. The first selection unit 101 selects the virtual node vn of the virtual network VN to be assigned to one base node sn of the base network SN. In the present embodiment, as described with respect to step S2 of FIG. 4, the virtual node vn is usually selected in descending order of the required capacity.

The second selection unit 102 selects the base node sn that is a candidate for the allocation destination of the selected virtual node vn. In the present embodiment, as described with respect to steps S302 and S303 of FIG. 5, base node sns whose free capacity is equal to or larger than the required capacity of the selected normal virtual node vn are selected in descending order of free capacity.

The distance calculation unit 20 includes a first calculation unit 201 and a second calculation unit 202. The first calculation unit 201 calculates the distance between the virtual nodes based on the above equation (3). The second calculation unit 201 calculates the distance between the base nodes based on the above equation (2).

The allocation unit 30 includes a cooperation virtual node allocation unit 301, a normal virtual node allocation unit 302, and a virtual link allocation unit 303.

As described with reference to the flowchart of FIG. 6, the cooperative virtual node allocation unit 301 calculates the average distance on the infrastructure network SN to the other shared infrastructure nodes sn for each shared infrastructure node sn, and calculates the average distance thereof. Each shared infrastructure node sn is sorted in ascending order (steps S101 and S102).

Further, for each linked virtual node vn, the average distance on the linked virtual network VN to another linked virtual node vn is calculated, and each linked virtual node vn is sorted in ascending order (steps S103 and S104). Then, each linked virtual node vn is assigned to each shared infrastructure node having the same sort order of average distances.

As described with reference to the flowchart of FIG. 5, the normal virtual node allocation unit 302 includes each distance sdistance on the underlying network calculated by the second calculation unit and the virtual calculated by the first calculation unit 201. When the distance ratio (sdistance / vdistance) with each corresponding distance vdistance on the network falls below the predetermined reference value margin, the selected normal virtual node is assigned to the base node of the current allocation destination candidate.

As described with respect to steps S5, S6, and S7 of FIG. 4, the virtual link allocation unit 303 sequentially selects one of the virtual links vl of the linked virtual network VN in descending order using the requested bandwidth as an index. Repeatedly assigning this to the base path of the base network SN.

10 ... node selection unit, 20 ... distance calculation unit, 30 ... allocation unit, 101 ... first selection unit, 102 ... second selection unit, 201 ... first calculation unit, 202 ... second calculation unit, 301 ... cooperation virtual node Allocation unit, 302 ... Normal virtual node allocation unit, 303 ... Virtual link allocation unit

Claims (18)

In the method of allocating a virtual network composed of virtual nodes including virtual nodes to the infrastructure network composed of the infrastructure nodes.
The first step of selecting an unallocated normal virtual node and a pair of unallocated base nodes that are candidates for its allocation destination, and
The distance ratio between the distance between the selected pair of unallocated base nodes and each allocated base node and the distance between the selected pair of unallocated normal virtual nodes and each allocated virtual node, respectively. The second step to calculate and
When each of the distance ratios falls below a predetermined reference value, the third step of allocating the unallocated normal virtual node to the base node of the allocation destination candidate, and
A collaborative virtual network allocation method including a fourth procedure in which the first to third steps are repeated. The fifth step of selecting each virtual link of the virtual network in descending order of required bandwidth, and
The cooperative virtual network allocation method according to claim 1, further comprising a sixth step of allocating the selected virtual link to the corresponding infrastructure path of the infrastructure network. In the first step, unallocated normal virtual nodes are selected in descending order of their requested capacity, and unallocated base nodes are bases whose free capacity is equal to or greater than the required capacity of the selected unallocated normal virtual node. The cooperative virtual network allocation method according to claim 1 or 2, wherein the free capacity is selected from the node set in descending order. When a distance ratio that does not fall below a predetermined reference value is calculated in the third procedure, the first procedure is characterized in that an unallocated base node having the next largest free capacity is selected from the base node set. The cooperative virtual network allocation method according to claim 3. 4. When there is no unallocated base node whose distance ratio is less than a predetermined reference value in the base node set, the reference value is relaxed and the first to third steps are repeated. Linked virtual network allocation method described in. The virtual network includes a linked virtual node as a virtual node.
The infrastructure network includes a shared infrastructure node as an infrastructure node.
The cooperative virtual network allocation method according to any one of claims 1 to 5, further comprising a procedure of allocating each cooperative virtual node to any of the shared infrastructure nodes before the first procedure. The procedure for assigning each linked virtual node to one of the shared infrastructure nodes is as follows.
For each shared infrastructure node, the procedure for calculating the average distance on the infrastructure network to other shared infrastructure nodes, and
For each linked virtual node, including the procedure to calculate the average distance on the virtual network to other linked virtual nodes.
The cooperative virtual network allocation method according to claim 6, wherein each linked virtual node is assigned to each shared infrastructure node in ascending order of each average distance. It is defined that the distance between the base nodes on the base network becomes shorter as the free space of the base node as the starting point becomes larger, and becomes shorter as the free bandwidth of the base path connecting the base nodes becomes larger. The cooperative virtual network allocation method according to any one of claims 1 to 7, wherein the linked virtual network is allocated. It is defined that the distance between virtual nodes on the virtual network becomes shorter as the required capacity of the virtual node as the starting point increases, and becomes shorter as the required bandwidth of the virtual path connecting the virtual nodes increases. The cooperative virtual network allocation method according to any one of claims 1 to 8, wherein the linked virtual network allocation method is characterized. The distance between the base nodes on the base network is the reciprocal of the free capacity of the base node that is the starting point and the reciprocal of the free bandwidth of each base link that constitutes the base path from the base node at the starting point to the base node at the other end. The cooperative virtual network allocation method according to claim 8, wherein the sum is obtained based on the weighted sum. The distance between the virtual nodes on the virtual network is the reciprocal of the required capacity of the virtual node that is the starting point, and the required bandwidth of each virtual link that constitutes the virtual path that connects the virtual node at the starting point and the virtual node at the other end. The cooperative virtual network allocation method according to claim 9, wherein the reciprocal sum is obtained based on a weighted sum. In a virtual network allocation device that allocates a virtual network composed of virtual nodes including normal virtual nodes to a base network composed of infrastructure nodes including normal infrastructure nodes.
The first selection method for selecting a normal virtual node to be assigned to the base node,
A second selection means for selecting the selected normal virtual node allocation destination candidate from the base node group that is the normal virtual node allocation destination candidate, and
The first calculation means for calculating the distance vdistance on the virtual network between the selected normal virtual node and each virtual node assigned to the base node, and
A second calculation means for calculating the distance sdistance between the base node of the allocation destination candidate and each base node to which the virtual node has been assigned on the base network, respectively.
When the distance ratio between the distance sdistance on the base network and the corresponding distance vdistance on the virtual network falls below a predetermined reference value, the selected normal virtual node is transferred to the base node of the allocation destination candidate. A collaborative virtual network allocation device characterized in that it is provided with a normal virtual node allocation means for allocation. When the normal virtual node allocating means determines that at least one of the distance ratios does not fall below a predetermined reference value, the second selection means switches the base node as an allocation destination candidate to another base node. The cooperative virtual network allocation device according to claim 12. The cooperative virtual network allocation according to claim 12 or 13, further comprising a virtual link allocation means for selecting each virtual link of the virtual network in descending order of the required bandwidth and assigning it to the corresponding infrastructure path of the infrastructure network. apparatus. The virtual network includes a linked virtual node as a virtual node.
The infrastructure network includes a shared infrastructure node as an infrastructure node.
One of claims 12 to 14, further comprising a cooperative virtual node allocation means for allocating each cooperative virtual node to any of the shared infrastructure nodes before assigning each normal virtual node to any of the infrastructure nodes. The cooperative virtual network allocation device described in. The linked virtual node allocation means
A means to calculate the average distance on the infrastructure network to other shared infrastructure nodes for each shared infrastructure node,
Each linked virtual node is equipped with a means for calculating the average distance on the virtual network to other linked virtual nodes.
The cooperative virtual network allocation device according to claim 15, wherein each cooperative virtual node is assigned to each shared infrastructure node in ascending order of each average distance. In the first calculation means, the distance vdistance between virtual nodes on the virtual network becomes shorter as the required capacity of the virtual node as the starting point becomes larger, and becomes shorter as the required bandwidth of the virtual path connecting the virtual nodes becomes larger. The cooperative virtual network allocation device according to any one of claims 12 to 16, wherein the linked virtual network allocation device is defined as follows. In the second calculation means, the distance sdistance between the base nodes on the base network becomes shorter as the free space of the base node as the starting point increases, and becomes shorter as the free bandwidth of the base path connecting the base nodes increases. The cooperative virtual network allocation device according to any one of claims 12 to 17, wherein the linked virtual network allocation device is defined as follows.

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