CN105681153A - Virtual network mapping method and device - Google Patents

Abstract

The embodiment of the invention discloses a virtual network mapping method and a device, and the method comprises the steps: when a virtual network requirement arrives, according to candidate physical node range corresponding to each virtual node nV, all candidate physical node sets nV<*> corresponding to virtual nodes are aggregated; the candidate physical nodes nV<*> of bottom physical network are connected in the same way of bottom physical network; available physical links in the reconstituted bottom physical network are determined, the available physical links corresponding to virtual links lij form an available physical link set and calculate link availability of each physical link and link availability of each virtual link, and the links are sorted in descending according to the link availability; mapping is performed on the virtual network according to the sorted available physical link set and the virtual links. According to the invention, the embodiment of the invention is applied to realize virtual network mapping in SDN environment and reduce the mapping cost.

Description

A kind of mapping method of virtual network and device

Technical field

The present invention relates to network virtualization technical field, particularly to a kind of mapping method of virtual network and device.

Background technology

Network virtualization technology is the important means of network resources locating in future network, virtual network (the VN of the multiple isomery of this technical support, virtualnetwork) coexist in Same Physical network with being isolated from each other, be conducive to improving the utilization rate of the VN motility created and physical network resource. Under network virtualization environment, virtual network provider (VNP, virtualnetworkprovider) is responsible for generating VN request, and rents physical resource according to request; Infrastructure provider (InP, infrastructureprovider) is responsible for providing the physical resource of carrying VN.

Owing to legacy network framework has very strong limitation, being badly in need of a kind of new network architecture and meet the multiformity needs of user with relatively low cost, software defined network (SoftwareDefinedNetwork, SDN) is suggested and obtains and is widely recognized as. SDN can be considered a kind of brand-new network technology, it passes through chain of command and the data surface of separated network equipment, it is supplied to application layer for application programming interfaces (API:ApplicationProgrammingInterface) by abstract for the ability of network, thus constructing open programmable network environment, to on the virtualized basis of the various Internet resources of bottom, it is achieved that the centralized control and management to network. At present, FlowVisor can realize observing under SDN environment the virtual network division of the switch of OpenFlow agreement.

Virtual network under SDN environment maps has a lot of differences with traditional virtual network mapping, so makes some be applicable to the virtual network mapping that the algorithm of traditional virtual network mapping cannot be completely suitable under SDN environment. such as: in document one: " Designandanalysisoftechniquesformappingvirtualnetworksto software-definednetworksubstrates " (Chinese: " in software defined network environment the design and analysis of virtual network mapping techniques ") devises two kinds of algorithms, first is based on time delay minimum mapping algorithm and the virtual network in SDN environment is mapped, first this algorithm determines that load minimal physical node is controller node, the available physical node selecting distance controller node time delay afterwards successively minimum carries out dummy node mapping, to reach the purpose that between final controller node and dummy node, average delay is minimum,Virtual network in SDN environment is mapped by second mapping algorithm being based on load balancing, first the method determines that load minimum node is controller node, after controller node is chosen, find the available physical node set in time delay allowed band, node maximum for CPU request in dummy node is mapped on the node that in physical node set, load is minimum, it is sequentially carried out, finally realizes load balancing mapping algorithm. Two kinds of mapping schemes in document one can cause that the average number of hops mapped is more so that mapping cost is bigger.

In document two: " ViNEYard:VirtualNetworkEmbeddingAlgorithmsWithCoordinate dNodeandLinkMapping. " (Chinese: " ViNEYard: the virtual network mapping algorithm of cooperative nodes and link maps ") proposes the traditional virtual network mapping scheme of a kind of cooperative node and link maps, this mapping scheme proposes to set up augmentation figure in mapping range at dummy node, and then carry out integral linear programming, eventually find optimum mapping point. But the algorithm of this cooperative node and link maps is the algorithm of traditional virtual network mapping, it is impossible to be entirely applied in SDN environment.

Summary of the invention

The purpose of the embodiment of the present invention is in that to provide a kind of mapping method of virtual network and device, it is adaptable to the virtual network in SDN environment maps, and reduces mapping cost.

For reaching above-mentioned purpose, the embodiment of the invention discloses a kind of mapping method of virtual network, described method includes step:

When a virtual network requests arrives, according to dummy node n each in described virtual network^VCorresponding candidate physical range of nodes, is polymerized all candidate physical node set n corresponding to each dummy node^V*;

According to the candidate physical node set n corresponding to each dummy node after polymerization^V*, by the candidate collection node n of bottom physical network^V*It is attached according to the connected mode identical with bottom physical network, reconstructs bottom physical network;

Determine the available physical link in the bottom physical network after described reconstruct, by every virtual link l^ijCorresponding available physical link composition available physical link set

Calculate described each available physical link setIn the link availability of each virtual link in the link availability of each physical link and described virtual network, and respectively it is carried out descending sort according to link availability;

According to the available physical link set after each sequenceAnd virtual link, described virtual network is mapped.

Concrete, in the described bottom physical network determining after described reconstruct available physical link, including:

Judge whether the available bandwidth of each physical link in the bottom physical network after described reconstruct meets the available CPU of two physical nodes of described virtual network requests, described each physical link and whether available stream entry meets described virtual network requests successively;

The physical link that above-mentioned condition is satisfied by described virtual network requests is defined as available physical link.

Concrete, the described each available physical link set of described calculatingIn the link availability of each virtual link utilizes in the link availability of each physical link and described virtual network formula include:

LC (l)=(1-α) * ln (bw (l_in))+α*Number(l_out)

Wherein α is the determined weighted value of the network size according to virtual network, l_inRepresent the available bandwidth of this link, Number (l_out) represent the number of links sum that two nodes of this link are connected respectively with other nodes, for physical link, other nodes described are the physical node beyond the candidate physical range of nodes corresponding to this physical node.

Concrete, described according to the available physical link set after each sequenceAnd virtual link, described virtual network is mapped, including:

A, the virtual link l maximum to link availability^ijMap, by virtual link l^ijCorresponding available physical link setThe physical link l that link availability is maximum_uvAllocation map is to virtual link l^ij, by this physical link l_uvA physical node n_uJoin the available physical node set of correspondenceIn, another physical node n_vJoin the available physical node set of correspondenceIn;

B, judges current available physical network node set respectivelyWithIn whether there are two physical nodes, if it is, enter step C; Otherwise, step E is entered;

C, finds the shortest path between said two physical node, the physical node n being simultaneously newly added_uFrom available physical network node setMiddle deletion, and judge whether described shortest path meets virtual link request amount, if entering step D; Otherwise enter step E;

D, by virtual link l^ijWhen mapping through the described physical node n deleted from available physical network node set_u;

E, by described available physical link setThe physical link l that link availability is maximum_uvFrom available physical link setMiddle deletion, and select described available physical link setTime big physical link of link availability is as the maximum physical link l of link availability_uvReturn step A to virtual link l^ijMap;

F, it is judged that the virtual link l that described link availability is maximum^ijWhether it is last in virtual link, if it is, perform step H, otherwise using next virtual link as the maximum virtual link l of link availability^ij, return step A;

H, by available physical network node setIn physical node be mapped to dummy node nⁱ;

I, by minimum for jumping figure and meet the non-mapped physical node of delay requirement and be mapped as controller node.

For reaching above-mentioned purpose, the embodiment of the invention also discloses a kind of virtual network mapping device, described device includes:

Candidate physical node aggregation unit, for when a virtual network requests arrives, according to dummy node n each in described virtual network^VCorresponding candidate physical range of nodes, is polymerized all candidate physical node set n corresponding to each dummy node^V*;

Bottom physical network reconfiguration unit, for all candidate physical node set n corresponding to each dummy node after polymerization^V*, by the candidate collection node n of bottom physical network^V*It is attached according to the connected mode identical with bottom physical network, reconstructs bottom physical network;

Available physical link set determines unit, is used for the available physical link in the bottom physical network after determining described reconstruct, by every virtual link l^ijCorresponding available physical link composition available physical link set

Link Calculation of Availability unit, is used for calculating described each available physical link setIn the link availability of each virtual link in the link availability of each physical link and described virtual network, and respectively it is carried out descending sort according to link availability;

Virtual network map unit, for according to the available physical link set after each sequenceAnd virtual link, described virtual network is mapped.

Concrete, described available physical link set determines unit, including:

Judgment sub-unit, whether the available CPU and the available stream entry that whether meet two physical nodes of described virtual network requests, described each physical link for the available bandwidth of each physical link in the bottom physical network after judging described reconstruct successively meet described virtual network requests;

Available physical link determines subelement, and the physical link for above-mentioned condition is satisfied by described virtual network requests is defined as available physical link.

Concrete, described link Calculation of Availability unit calculates described each available physical link setIn the link availability of each virtual link utilizes in the link availability of each physical link and described virtual network formula include:

LC (l)=(1-α) * ln (bw (l_in))+α*Number(l_out)

Wherein α is the determined weighted value of the network size according to virtual network, bw (l_in) represent the available bandwidth of this link, Number (l_out) represent the number of links sum that two nodes of this link are connected respectively with other nodes, for physical link, other nodes described are the physical node beyond the candidate physical range of nodes corresponding to this physical node.

Concrete, described virtual network map unit, including:

Link maps subelement, for the virtual link l that link availability is maximum^ijMap, by virtual link l^ijCorresponding available physical link setThe physical link l that link availability is maximum_uvIt is mapped to virtual link l^ij, by this physical link l_uvA physical node n_uJoin the available physical node set of correspondenceIn, another physical node n_vJoin the available physical node set of correspondenceIn;

First judgment sub-unit, for judging current available physical network node set respectivelyWithIn whether there are two physical nodes, if it is, trigger first process subelement; Otherwise trigger the second process subelement;

Described first processes subelement, for finding the shortest path between said two physical node, the physical node n being newly added simultaneously_uFrom available physical network node setMiddle deletion, and judge whether described shortest path meets virtual link request amount, if triggering through subelement; Otherwise trigger the second process subelement;

Described through subelement, for by virtual link l^ijWhen mapping through the described physical node n deleted from available physical network node set_u;

Described second processes subelement, for by described available physical link setThe physical link l that link availability is maximum_uvFrom available physical link setMiddle deletion, and select described available physical link setTime big physical link of link availability is as the maximum physical link l of link availability_uvTrigger link maps subelement to virtual link l^ijMap;

Second judgment sub-unit, for judging the virtual link l that described link availability is maximum^ijWhether it is last in virtual link, if it is, trigger node maps subelement, otherwise using next virtual link as the maximum virtual link l of link availability^ij, trigger link maps subelement;

Node maps subelement, for by available physical network node setIn physical node be mapped to dummy node nⁱ;

Controller node maps subelement, for by minimum for jumping figure and meet the non-mapped physical node of delay requirement and be mapped as controller node.

In sum, a kind of mapping method of virtual network described in the embodiment of the present invention and device, according to the candidate physical range of nodes corresponding to dummy node each in virtual network, bottom physical network is effectively simplified, and then reduces mapping complex; The virtual link that preferential mapping link availability is maximum, it is possible to effectively reduce virtual link and map average number of hops, reduces the consumption that makes of bandwidth and stream entry, and then reduces mapping cost, increase and map income; Simultaneously after completing link maps and node maps, select jumping figure minimum and meet the non-mapped physical node of delay requirement as controller node, it is determined that the position of controller node. ?irtual network in China fir ? ? convulsion 19. black mole stool ├ ? ? bucktooth nurse oar sweet Shi Mi Yun DN environment maps, it is possible to reduce mapping cost.

Certainly, arbitrary product or the method for implementing the present invention must be not necessarily required to reach all the above advantage simultaneously.

Accompanying drawing explanation

In order to be illustrated more clearly that the embodiment of the present invention or technical scheme of the prior art, the accompanying drawing used required in embodiment or description of the prior art will be briefly described below, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, under the premise not paying creative work, it is also possible to obtain other accompanying drawing according to these accompanying drawings.

The schematic flow sheet of a kind of mapping method of virtual network that Fig. 1 provides for the embodiment of the present invention;

Virtual network requests schematic diagram, bottom physical network schematic diagram, polymeric base layer physical network schematic diagram, simplification bottom physical network schematic diagram in the specific embodiment that (a) (b) (c) (d) in Fig. 2 respectively the invention process provides;

A kind of mapping method of virtual network of the respectively embodiment of the present invention of (a) (b) (c) in Fig. 3 offer and other mapping method of virtual network contrast schematic diagram in average number of hops, average overhead and stream entry efficiency three;

The structural representation of a kind of virtual network mapping device that Fig. 4 provides for the embodiment of the present invention.

Detailed description of the invention

Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is clearly and completely described, it is clear that described embodiment is only a part of embodiment of the present invention, rather than whole embodiments. Based on the embodiment in the present invention, the every other embodiment that those of ordinary skill in the art obtain under not making creative work premise, broadly fall into the scope of protection of the invention.

The understanding of a kind of mapping method of virtual network for the ease of the embodiment of the present invention is provided, first introduces a kind of mapping method of virtual network the principle on which content that the embodiment of the present invention provides. It is specifically described as follows:

Bottom physical network represents with undirected weighted graph, uses G in embodiments of the present invention^S=(N^S, E^S) represent bottom physical network topology, wherein N^SAnd E^SRepresent physics node set and physical link set respectively. For physical node set N^S=(N^SC, N^SS), N^SCRepresent the set of Servers-all node, represent that bottom physical network calculates resource capability; N^SSIt is the set of all telephone net nodes supporting OpenFlow agreement, is responsible for forwarding message. The embodiment of the present invention assumes each telephone net node N^SSAll it is connected with one or more server nodes. In order to simplify bottom physical network, unification N in the present invention^SRepresent physics node set, be no longer switch or server makes a distinction to physical node. Each physical node n^S(n^S∈N^S) association attributes be with includes: physical node CPU ability, physical node stream entry, physical node geographical position, wherein physical node CPU ability c (n^S) represent, physical node stream entry fe (n^S) represent, physical node geographical position loc (n^S) represent. e^S(u,v)∈E^SRepresent the physical link connected between physical node u and physical node v. The attribute of each physical link includes: link bandwidth bw (e^S) and propagation delay time d (eⁿ)。P^S(s d) is used for representing the set of all physical links between physical node s to physical node d.Identical with bottom physical network, virtual network G^V=(N^V,E^V) ask also to represent with undirected weighted graph, each of which dummy node n^V(n^V∈N^V) attribute be with comprises its CPU request c (n^V), stream entry request amount fe (n^V) and wish to map physical location scope R. Bw (e^V) it is used to characterize virtual link e^V(e^V∈E^V) bandwidth on demand. For each virtual network requests, a maximum transmitted time delay D is used to characterize link maps delay requirement.

In order to the bottom physical network in the SDN environment supported at OpenFlow realizes virtual network mapping scheme, the present invention needs to pre-build dummy node mapping model, controller node mapping model, virtual link mapping model. After specify that node, controller and link maps model, the present invention can further describe income and the mapping cost that virtual network maps, and then clear and definite goal of the invention is for minimizing virtual network mapping cost. Finally, in order to realize minimizing expense mapping scheme, it is proposed to integral linear programming simplifies mapping process. This three step will be described in detail below.

Dummy node mapping model, controller node mapping model, virtual link mapping model are specifically described as follows:

Node mapping process can be described as M^N:N^V→N^S, wherein M^N(n^V)∈N^S,n^V∈N^V. In order to ensure calculating distributing rationally of resource, it should be ensured that the different dummy nodes in same virtual network are mapped on the different physical nodes of bottom physical network, therefore can drawWherein m^VFor dummy node. Physical node n^SLoad be defined as this physical node n^SCPU make consumption and stream entry occupancy weighted sum. Switch owing to observing OpenFlow agreement in SDN environment can not actively calculate routing plan, and they have to comply with the stream entry instruction forwarded by controller node being stored in fluid space, carries out forwarding operation to information according to these stream entry instruction. Therefore, for a physical node n^S, its stream entry occupancy is made up of two parts: Part I is that dummy node is mapped to physical node n^SBrought node forwards the stream entry occupancy of rule, and Part II is virtual link traverse physical node n^SThe increase part of caused stream list item. More precisely, if S_N(n^S) represent physical node n^SNode load pressure, said process represents by following formula:

S_N(n^S)=a.S_NC(n^S)+b.S_NF(n^S),

$S_{NC}\left(n^S\right)={\mathrm{\&Sigma;}}_{M^N\left(n^V\right)=n^{SC}}\left(n^V\right),$

$S_{NF}\left(n^S\right)={\mathrm{\&Sigma;}}_{M^N\left(n^V\right)=n^S}fe\left(n^V\right)+{\mathrm{\&Sigma;}}_{\underset{{\mathrm{traversesn}}^S}{\&ForAll;l^{ij}}}fe\left(l^{ij}\right);$

Wherein, S_NC(n^S) represent physical node n^SCPU make consumption, S_NF(n^S) represent physical node n^SStream entry occupancy, coefficient a and b represents physical node n respectively^SCPU make consumption and stream entry occupancy weighted value,Represent dummy node and be mapped to physical node n^SBrought node forwards the stream entry occupancy of rule,Represent virtual link l^ijThrough physical node n^SThe increase part of caused stream list item.

Namely physical node n is will be mapped to for one^S∈N^SOn dummy node n^V∈N^V, its CPU request amount c (n^V) and stream entry request amount fe (n^V) not can exceed that the maximum available limit of the physical resource of this physical node, if usedWithRepresent physical node n respectively^SAvailable CPU and available stream entry, above mapping process can characterize by following formula:

When maps virtual network request, owing to FlowVisor needs each virtual network to have the controller node of himself, it is therefore necessary to solve emphatically the demapping section of controller node. Owing to controller node arbitrarily can select in available bottom physical network, the mapping process equation below of middle controller node of the present invention characterizes: M^N(n^C)=n^SC, n^CFor the controller node in virtual network, n^SCFor bottom physical network is selected as the physical node of controller node.Propagation delay time between controller node and the physical node of each mapping d (n^SC,M^N(n^V)) represent. Owing to the propagation delay time between controller node and switch have to be limited within the scope of certain, just can ensure that forwarding information is received by switch rapidly, therefore said process can characterize by equation below:

n^SC∩M^N(n^V)=φ,

d(n^SC,M^N(n^V))≤D。

It should be noted that can have enough resources to calculate bottom forwarding information in order to ensure controller node, if the embodiment of the present invention being assumed, a node is selected as controller, then it can not be used till this virtual network discharges by other nodes again.

Virtual link mapping process M^E:E^V→P^SCharacterize. For a physical link e^S∈E^S, its link load S_L(e^S) including two parts: Part I is data transmission link load S_LD(e^S), Part II is for controlling link load S_LC(e^S). The embodiment of the present invention have employed the band outer control scheme of OpenFlow agreement, reserved a part of bandwidth for controlling link. Therefore, data transmission link load S_LD(e^S) it is by virtual link traverse physical link e^SGenerated, controlled link load S_LC(e^S) be by controller node to switch path transmission cause. Above-mentioned all processes can be represented by formula below:

M^E:E^V→P^S,

S_L(e^S)=S_LD(e^S)+S_LC(e^S),

$S_{LD}\left(e^S\right)={\mathrm{\&Sigma;}}_{e^S\&Element;M^E\left(e^V\right)P^S}bw\left(e^V\right),$

$S_{LC}\left(e^S\right)={\mathrm{\&Sigma;}}_{\underset{e^S\&Element;M^E(n^C,n^V)=P^S}{\&ForAll;(n^C,n^V),}}bw(n^C,n^V).$

The available bandwidth of physical link is usedRepresent, and virtual link l^ijIt is mapped to bottom physical link P^SIts desire bandwidth have to be met less than or equal to link P^SAvailable bandwidth, said process can represent by following equation:

bw(l^ij)≤bw(P^S),

It is noted that when virtual link is mapped with multi-hop, virtual link l^ijDuring through intermediate physical node, it will occupy the fluid space of intermediate physical node. Owing to the stream entry of this intermediate physical node makes consumption be difficult to estimate, can according to the change of portfolio real-time change, adopt a kind of extreme mode to go this situation is assumed in the present invention: for virtual link l^ij, fe (i) and fe (j) represents virtual link l respectively^ijThe stream entry request amount of two ends dummy node i and j, if virtual link l^ijThrough intermediate physical node, it is assumed that the maximum of the stream entry request amount that intermediate physical node upper reaches entry makes consumption be two ends dummy node i and j. The present invention defines physical pathway P^SOn available stream entry be the minima of residual stream entry on all physical nodes of this path traverse, as virtual link l^ijMapping result is multi-hop traverse physical pathway P^STime, it is desirable to virtual link l^ijRequired stream entry makes consumption less than or equal to residual stream number of entries in this physical pathway. Said process can be expressed by formula the following:

fe(l^ij)=max (fe (i), fe (j)),

fe(l^ij)≤fe(P^S),

In the present invention, our target is while using minimum mapping cost, it is thus achieved that more map income, it is therefore desirable to virtual network mapping cost and income formula in definition SDN environment. Similar with traditional virtual network mapping, virtual network maps income Rev (G^V) it is:

$\mathrm{Re}v\left(G^V\right)={\mathrm{\&Sigma;}}_{e^V\&Element;E^V}bw\left(e^V\right)+{\mathrm{\&Sigma;}}_{n^V\&Element;N^V}C\left(n^V\right).$

But, owing to the virtual network in SDN environment maps different from traditional virtual network mapping, virtual network in SDN environment is mapped in the many stream entry expenses of expense aspect, and therefore the present invention defines the virtual network mapping cost Cost (G in SDN environment^V) comprising three parts: Part I is bandwidth cost Costbw (G^V), Part II is CPU overhead Costc (G^V), Part III is stream entry expense Cosfe (G^V). Therefore, in SDN environment, virtual network mapping cost can be indicated by following formula:

Cost(G^V)=ε₁Costbw(G^V)+ε₂Costc(G^V)+ε₃Cosfe(G^V), wherein ε₁, ε₂、ε₃The respectively expense adjustment factor of bandwidth cost, CPU overhead, stream entry expense.

Virtual network mapping cost minimal definition in SDN environment is integral linear programming (ILP) process by the embodiment of the present invention. When calculating the overall overhead of virtual network, it is necessary to controller node is put into virtual network requests N^VIn, new for the new augmentation figure N of virtual network requests controlling node^V′Represent, at N^V′In, controller node is expressed as (N+1) individual node, and it is connected with each dummy node, and these links are for controlling link. The CPU overhead that maps due to each dummy node and what stream entry expense determined that, therefore it is not variable, does not include this part in object function.

First following two variable is illustrated:

For binary variable, when there being stream l^ij∈E^V′It is routed across physical link l_uv∈E^STime, this variable-definition is 1; On the contrary, 0 it is defined as.

For binary variable, as dummy node i ∈ N^V′It is mapped to physical node u ∈ N^STime, this variable-definition is 1; On the contrary, 0 it is defined as.

The object function of integral linear programming problem is:

$\min \underset{ij\&Element;E^{V^{\&prime;}}}{\&Sigma;}\underset{uv\&Element;E^S}{\&Sigma;}{\mathrm{\&alpha;}}_{uv}{f}_{uv}^{ij}bw\left(l^{ij}\right)+\underset{ij\&Element;E^{V^{\&prime;}}}{\&Sigma;}{\mathrm{\&beta;}}_{uv}\left(\right(\underset{uv\&Element;E^S}{\&Sigma;}{f}_{uv}^{ij}-1\left)fe\right(l^{ij}\left)\right)$

The restrictive condition of this object function is as follows:

1, capacity limit:

2, position limitation:

$\&ForAll;i\&Element;N^V,\&ForAll;u\&Element;N^S:\left\{\begin{array}{c}{x}_u^i\&times;Dis\left(Loc\right(u),Loc\left(i\right))\&le;R\\ x_u^{N+1}\&times;x_v^i\&times;D_{uv}\&le;D\end{array}\right.---\left(3\right)$

3, connectivity restriction:

${\&Sigma;}_{uv\&Element;E^S}{f}_{uv}^{ij}-{\&Sigma;}_{vu\&Element;E^S}{f}_{vu}^{ij}=\left\{\begin{array}{cc}1,& \begin{array}{cc}if& x_u^i=1\end{array}\\ -1,& \begin{array}{cc}if& x_u^i=1\end{array}\\ 0,& otherwise\end{array}\right.\&ForAll;i,j\&Element;N^{V^{\&prime;}}---\left(4\right)$

$\begin{array}{cc}{f}_{uv}^{ij}\&times;x_u^{N+1}=0& \&ForAll;(i,j)\&Element;E^V,\&ForAll;(u,v)\&Element;E^S\end{array}---\left(5\right)$

4, variable restriction:

$\&ForAll;i\&Element;N^V,\&ForAll;u\&Element;N^S,x_u^i\&Element;\{0,1\}:\left\{\begin{array}{c}{\&Sigma;}_{i\&Element;N^{V^{\&prime;}}}{x}_u^i\&le;1\\ {\&Sigma;}_{u\&Element;N^S}{x}_u^i=1\end{array}\right.---\left(6\right)$

$f_{uv}^{ij}\&Element;\{0,1\},x_u^i\&Element;\{0,1\}\&ForAll;(i,j)\&Element;E^{V^{\&prime;}},\&ForAll;(u,v)\&Element;E^S---\left(7\right)$

The related description of above-mentioned formula is as follows:

The object function of integral linear programming (ILP) includes two parts: what the first summation part and the second summation part referred to respectively is link maps consumption and stream entry mapping consumption part, whereinIt is used for calculating virtual link l^ijMapping jumping figure. Weight coefficient α_uvAnd β_uvCan be used to regulate physical link l_uvBandwidth with stream entry load;

Formula (1) is virtual link k^ijRestriction to bandwidth, stream entry, formula (2) is the dummy node i restriction to CPU, stream entry;

Formula (3) is the dummy node i mapping geographic range required, also needs in addition its maximum transmitted time delay is limited, it is impossible to exceed its threshold value D;

Formula (4) convection current conservation has guaranteed, formula (5) ensure that virtual link maps and cannot pass through controller node;

Formula (6) represents that a dummy node can only be mapped on a physical node, and formula (7) ensure that the two variable is binary variable.

Based on above-mentioned introduced principle content, a kind of mapping method of virtual network that the embodiment of the present invention provide is described below.

Fig. 1 illustrates the flow chart of a kind of mapping method of virtual network that the embodiment of the present invention provides.

As it is shown in figure 1, a kind of mapping method of virtual network that the embodiment of the present invention provides may include steps of:

S101, when a virtual network requests arrives, according to dummy node n each in described virtual network^VCorresponding candidate physical range of nodes, is polymerized all candidate physical node set n corresponding to each dummy node^V*;

In actual applications, owing to, in virtual network mapping process, each dummy node can have its candidate physical range of nodes, therefore the embodiment of the present invention utilizes this candidate physical range of nodes that complicated bottom physical network is simplified. Due to each dummy node n^V∈N^VHaving a candidate physical range of nodes R, this scope represents the Geoposition Request scope of dummy node, and dummy node must be mapped on the physical node in this scope, and this candidate physical node set is usedRepresent. Therefore, the embodiment of the present invention is with a new node n^V*Represent the physical node set of this polymerizationPhysical network is simplified with this.

For example, containing three dummy nodes a, b, c in the virtual network requests schematic diagram as shown in Fig. 2 (a), three virtual link l^ab、l^bc、l^ac, wherein, the CPU request amount (c (n of dummy node a^V)) be 9, flow entry request amount (fe (n^V)) it is 20, the CPU request amount (c (n of dummy node b^V)) be 8, flow entry request amount (fe (n^V)) it is 40, the CPU request amount (c (n of dummy node c^V)) be 5, flow entry request amount (fe (n^V)) it is 60, virtual link l^abBandwidth request amount (bw (e^V)) it is 50, virtual link l^bcBandwidth request amount (bw (e^V)) it is 30, virtual link l^acBandwidth request amount (bw (e^V)) it is 40.For each dummy node, its candidate physical node is the physical node in broken box corresponding in Fig. 2 (b), and wherein the candidate physical node set of dummy node a is a^*={ the candidate physical node set of A, G, J}, dummy node b is b^*={ the candidate physical node set of E, F, H}, dummy node c is c^*={ B, C}.

S102, according to all candidate physical node set n corresponding to each dummy node after polymerization^V*, by the candidate collection node n of bottom physical network^V*It is attached according to the connected mode identical with bottom physical network, reconstructs bottom physical network;

For example, in the polymeric base layer physical network schematic diagram as shown in Fig. 2 (c), according to all candidate physical node set a corresponding to each dummy node after polymerization^*={ A, G, J}, b^*={ E, F, H}, c^*={ B, C}, be attached the candidate collection node in bottom physical network according to the connected mode identical with bottom physical network, constitutes a simple bottom physical network such as shown in Fig. 2 (c).

S103, it is determined that the available physical link in bottom physical network after described reconstruct, by every virtual link l^ijCorresponding available physical link composition available physical link set

Concrete, in the described bottom physical network determining after described reconstruct available physical link, including:

Judge whether the available bandwidth of each physical link in the bottom physical network after reconstruct meets the available CPU of two physical nodes of described virtual network requests, described each physical link and whether available stream entry meets described virtual network requests successively;

The physical link that above-mentioned condition is satisfied by described virtual network requests is defined as available physical link.

For example, in the bottom physical network schematic diagram as shown in Fig. 2 (b), the available CPU of each physical nodeAvailable stream entryThe available bandwidth of part physical linkAs shown in the table:

In the polymeric base layer physical network schematic diagram shown in Fig. 2 (c), it is determined that the available physical link in bottom physical network after reconstruct, specific as follows: No. 1 physical link is l_AF, l_AFAvailable bandwidthIt is 90, meets virtual link l^abBandwidth requirement; The available CPU of physical node ABe 20, available stream entryIt is 100, meets the request amount of dummy node a; The available CPU of physical node FBe 25, available stream entryIt is 110, meets the request amount of dummy node b; Therefore the link availability of No. 1 physical link meets virtual network requests, by No. 1 physical link l_AFJoin virtual link l^abCorresponding available physical link setIn. The link availability of same other physical links in the bottom physical network after determination reconstruct. Although No. 4 link l_BGIt is an a^*To c^*Direct connected link, but the available CPU of physical node JThe request amount of dummy node a, No. 2 physical link l of direct connected link can not be met_FGVirtual link l can not be met^abBandwidth demand, No. 6 physical link l of direct connected link_HCVirtual link l can not be met^bcBandwidth demand, therefore No. 4 links, No. 2 links, No. 6 links are deleted and are not considered. Although physical node D, I are not the nodes in the alternative physical extent of dummy node, but virtual link can pass intermediate physical node D, I and realize link maps. No. 7 link l_CIWith No. 8 link l_HILink maps is realized through intermediate physical node I, but the available stream entry of intermediate physical node IBeing 50, be unsatisfactory for the request amount of dummy node c, therefore No. 7 links and No. 8 links are deleted and are left out.No. 9 link l_CDMeet virtual link l^bcRequest, No. 10 link l_HDWith No. 11 link l_EDAlso l is all met^bcRequest, and the available CPU of intermediate physical node DBe 35, available stream entryIt is 70, meets virtual request. Therefore according to determining the result of available physical network in the bottom physical network after reconstruct, available physical link corresponding to every virtual link is formed available physical link set, bottom physical network after being simplified is such as shown in Fig. 2 (d), wherein virtual link l^abCorresponding link availability meets the physical link composition available physical link set of virtual network requestsVirtual link l^bcCorresponding link availability meets the physical link composition available physical link set of virtual network requestsVirtual link l^acCorresponding link availability meets the physical link composition available physical link set of virtual network requests

S104, calculates described each available physical link setIn the link availability of each virtual link in the link availability of each physical link and described virtual network, and respectively it is carried out descending sort according to link availability;

Concrete, the described each available physical link set of described calculatingIn the link availability of each virtual link utilizes in the link availability of each physical link and described virtual network formula include:

LC (l)=(1-α) * ln (bw (l_in))+α*Number(l_out)

Wherein α is the determined weighted value of the network size according to virtual network, bw (l_in) represent the available bandwidth of this link, Number (l_out) represent the number of links sum that two nodes of this link are connected respectively with other nodes, for physical link, other nodes described are the physical node beyond the candidate physical range of nodes corresponding to this physical node. As shown in Fig. 2 (a), virtual link l^abNumber (l_AB) it is 2 (include virtual link l^bc,l^ac). As shown in Fig. 2 (b), physical link l_ABNumber (l_AB) it is 2 (include physical link l_AF,l_BJ); Link l_GCNumber (l_GC) it is 4 (include physical link l_GF, l_CH, l_CI, l_CD). Being measured by link availability above formula, this metric scheme can help to understand the impact that link is caused by topology.

For example, in the virtual network schematic diagram as shown in Fig. 2 (a), the l of virtual link^abLink availability LC (l^ab)=0.5*ln (50)+0.5*2=2.96, the l of virtual link^bcLink availability LC (l^bc)=0.5*ln (30)+0.5*2=2.70, the l of virtual link^acLink availability LC (l^ac)=0.5*ln (40)+0.5*2=2.84. Result after these 3 virtual links being carried out descending sort according to link availability is l^ab、l^ac、l^bc。

In simplification bottom physical network schematic diagram as shown in Fig. 2 (d), the link Calculation of Availability of every physical link is as follows: LC (l_AF)=0.5*ln (90)+0.5*2=3.250,

LC(l_AB)=0.5*ln (80)+0.5*2=3.191,

LC(l_GC)=0.5*ln (60)+0.5*4=4.047,

LC(l_CD)=0.5*ln (100)+0.5*5=4.803,

LC(l_HD)=0.5*ln (70)+0.5*4=4.124,

LC(l_DE)=0.5*ln (80)+0.5*2=3.191,

Wherein according to determined weight value α=0.5 of the network size of virtual network.

After the link availability calculating described 6 physical links, respectively the physical link in each available physical link set is carried out descending sort according to link availability, whereinWithRanking results be

S105, according to the available physical link set after each sequenceAnd virtual link, described virtual network is mapped;

Concrete, described according to the available physical link set after each sequenceAnd virtual link, described virtual network is mapped, including:

S401, the virtual link l maximum to link availability^ijMap, by virtual link l^ijCorresponding available physical link setThe physical link l that link availability is maximum_uvIt is mapped to virtual link l^ij, by this physical link l_uvA physical node n_uJoin the available physical node set of correspondenceIn, another physical node n_vJoin the available physical node set of correspondenceIn;

S402, judges current available physical network node set respectivelyWithIn whether there are two physical nodes, if it is, enter S403; Otherwise, S405 is entered;

S403, finds the shortest path between said two physical node, the physical node n being simultaneously newly added_uFrom available physical network node setMiddle deletion, and judge whether described shortest path meets virtual link request amount, if entering S404; Otherwise enter S405;

S404, by virtual link l^ijWhen mapping through the described physical node n deleted from available physical network node set_u;

S405, by described available physical link setThe physical link l that link availability is maximum_uvFrom available physical link setMiddle deletion, and select described available physical link setTime big physical link of link availability is as the maximum physical link l of link availability_uvEnter S401 to virtual link l^ijMap;

S406, it is judged that the virtual link l that described link availability is maximum^ijWhether it is last in virtual link, if it is, perform S407, otherwise using next virtual link as the maximum virtual link l of link availability^ij, return S401;

S407, by available physical network node setIn physical node be mapped to dummy node nⁱ;

S408, by minimum for jumping figure and meet the non-mapped physical node of delay requirement and be mapped as controller node.

For example, the virtual network requests as shown in Fig. 2 (a) and in the bottom physical network after the simplification shown in Fig. 2 (d), the ranking results according to step S104, described virtual network is mapped.

First the virtual link l that mapping link availability is maximum^ab, due to virtual link l^abCorresponding link availability meets the physical link composition available physical link set of virtual network requestsIn an only physical link l_AF, therefore by virtual link l^abIt is mapped to physical link l_AF, and by physical link l_AFA node A join available physical node set S corresponding for dummy node a^aIn, another node F joins available physical node set S corresponding for dummy node b^bIn, i.e. S^a={ A}, S^b={ F}.

Re-map the virtual link l that link availability time is big^ac, virtual link l^acCorresponding link availability meets the physical link composition available physical link set of virtual network requestsPhysical link l_ABWith physical link l_CGAll can maps virtual link l^acBut, physical link l_CGThere is higher link availability, therefore, virtual link l^acIt is mapped to physical link l_CGOn, and by physical link l_CGA node C join available physical node set S corresponding for dummy node c^cIn, another node G joins available physical node set S corresponding for dummy node a^aIn, i.e. S^a={ A, G}, S^c={ C}.

Due to current available physical network node set S^aMiddle existence two physical nodes A, G, therefore by the physical node G that is newly added from available physical network node set S^aMiddle deletion, and judge the shortest path l between the two physical node A, G_AGWhether meet virtual link l^acRequest amount.Physical link l_AGAvailable bandwidthIt is 70, the available CPU of intermediate physical node GBe 35, available stream entryIt is 70, meets virtual link l^acRequest amount, therefore by virtual link l^acWhen mapping through the described physical node G, virtual link l deleted from available physical network node set^acIt is mapped to physical link l_AGAnd l_GCOn, S simultaneously^a={ A}, S^c={ C}.

Then maps virtual link l^bc, by Fig. 2 (d) it can be seen that virtual link l^bcThrough physical node D, therefore virtual link l^bcPhysical link l can be selected during mapping_DHOr physical link l_DEBut, due to physical link l_DHHaving higher link can expenditure, therefore selection physical link l_DH. Now by virtual link l^bcIt is mapped to physical link l_DHAnd l_CDOn, and by physical link l_DHAnd l_CDA node H join available physical node set S corresponding for dummy node b^bIn, another node C joins available physical node set S corresponding for dummy node c^cIn, i.e. S^b={ F, H}, S^c={ C}.

Now, corresponding for dummy node b available physical node set S^bMiddle existence two physical nodes F, H, therefore by the physical node H that is newly added from available physical network node set S^bMiddle deletion, and judge the shortest path l between the two physical node F, H_FHWhether meet virtual link l^bcRequest amount. Physical link l_FHAvailable bandwidthIt is 20, is unsatisfactory for virtual link l^acRequest amount.

Accordingly, it would be desirable to by described physical link l_DHFrom virtual link l^bcCorresponding link availability meets the physical link composition available physical link set of virtual network requestsMiddle deletion, and select available physical link setThe physical link l that link availability time is big_DECome virtual link l^bcMap. Now by virtual link l^bcIt is mapped to physical link l_DEAnd l_CDOn, and by physical link l_DEAnd l_CDA node E join available physical node set S corresponding for dummy node b^bIn, another node C joins available physical node set S corresponding for dummy node c^cIn, i.e. S^b={ F, E}, S^c={ C}.

Now, corresponding for dummy node b available physical node set S^bMiddle existence two physical nodes F, E, therefore by the physical node E that is newly added from available physical network node set S^bMiddle deletion, and judge the shortest path l between the two physical node F, E_EFWhether meet virtual link l^bcRequest amount. Physical link l_EFAvailable bandwidthIt is 40, the available CPU of intermediate physical node EBe 20, available stream entryIt is 150, meets virtual link l^bcRequest amount, therefore by virtual link l^bcWhen mapping through the described physical node E, virtual link l deleted from available physical network node set^bcIt is mapped to physical link l_EF、l_DEAnd l_CDOn, S simultaneously^b={ F}, S^c={ C}.

After described virtual link all maps, dummy node is mapped as: by available physical network node set S^aIn physical node A be mapped to dummy node a, available physical network node set S^bIn physical node F be mapped to dummy node b, available physical network node set S^cIn physical node C be mapped to dummy node c.

The application embodiment of the present invention, according to the candidate physical range of nodes corresponding to dummy node each in virtual network, effectively simplifies bottom physical network, and then reduces mapping complex; The virtual link that preferential mapping link availability is maximum, it is possible to effectively reduce virtual link and map average number of hops, reduces the consumption that makes of bandwidth and stream entry, and then reduces mapping cost, increase and map income; Simultaneously after completing link maps and node maps, select jumping figure minimum and meet the non-mapped physical node of delay requirement as controller node, it is determined that the position of controller node. ?irtual network in China fir ? ? convulsion 19. black mole stool ├ ? ? bucktooth nurse oar sweet Shi Mi Yun DN environment maps, it is possible to reduce mapping cost.

In one particular embodiment of the present invention, GT-ITM instrument is utilized to generate bottom physical network topology and virtual network requests topology. Virtual network arrival rate is 4 to 8 every 100 intervals, 2000 virtual network requests of stochastic generation, in each virtual network requests, dummy node number obeys [2, being uniformly distributed 9], connect with the probability of 50% between dummy node, in addition physical node CPU and physical link bandwidth obey being uniformly distributed of [1,10] and [20,50] respectively.

The embodiment of the present invention is under different network sizes, by mapping method of virtual network (LF-OVNE) preferential for link of the present invention and the mapping method of virtual network (D-ViNE-SP) minimum based on time delay, mapping method of virtual network (R-ViNE-SP) based on load balancing, based on the mapping method of virtual network (G-MCF) that multiple commodity flow link maps and greedy algorithm node map, the mapping method of virtual network (G-SP) mapped based on shortest path link maps and greedy algorithm node is from average number of hops, average overhead and stream three aspects of entry efficiency contrast. as shown in Figure 3, a kind of mapping method of virtual network of the respectively embodiment of the present invention of (a) (b) (c) in Fig. 3 offer and other mapping method of virtual network contrast schematic diagram in average number of hops, average overhead, stream entry efficiency three, transverse axis is virtual network and reaches rate. by in Fig. 3 it can be seen that a kind of mapping method of virtual network provided by the present invention, in average number of hops, average overhead two, have bigger improvement.

Corresponding to said method embodiment, the embodiment of the present invention additionally provides a kind of virtual network mapping device, and the structural representation of a kind of virtual network mapping device that Fig. 4 provides for the embodiment of the present invention, as shown in Figure 4, described device may include that

Candidate physical node aggregation unit 401, for when a virtual network requests arrives, according to dummy node n each in described virtual network^VCorresponding candidate physical range of nodes, is polymerized all candidate physical node set n corresponding to each dummy node^V*;

Bottom physical network reconfiguration unit 402, for all candidate physical node set n corresponding to each dummy node after polymerization^V*, by the candidate collection node n of bottom physical network^V*It is attached according to the connected mode identical with bottom physical network, reconstructs bottom physical network;

Available physical link set determines unit 403, is used for the available physical link in the bottom physical network after determining described reconstruct, by every virtual link l^ijCorresponding available physical link composition available physical link set

Link Calculation of Availability unit 404, is used for calculating described each available physical link setIn the link availability of each virtual link in the link availability of each physical link and described virtual network, and respectively it is carried out descending sort according to link availability;

Virtual network map unit 405, for according to the available physical link set after each sequenceAnd virtual link, described virtual network is mapped.

The application embodiment of the present invention, according to the candidate physical range of nodes corresponding to dummy node each in virtual network, effectively simplifies bottom physical network, and then reduces mapping complex; The virtual link that preferential mapping link availability is maximum, it is possible to effectively reduce virtual link and map average number of hops, reduces the consumption that makes of bandwidth and stream entry, and then reduces mapping cost, increase and map income; Simultaneously after completing link maps and node maps, select jumping figure minimum and meet the non-mapped physical node of delay requirement as controller node, it is determined that the position of controller node. ?irtual network in China fir ? ? convulsion 19. black mole stool ├ ? ? bucktooth nurse oar sweet Shi Mi Yun DN environment maps, it is possible to reduce mapping cost.

Concrete, described available physical link set determines unit 403, it is possible to including:

Judgment sub-unit (not shown in Fig. 4), whether the available CPU and the available stream entry that whether meet two physical nodes of described virtual network requests, described each physical link for the available bandwidth of each physical link in the bottom physical network after judging described reconstruct successively meet described virtual network requests;

Available physical link determines subelement (not shown in Fig. 4), and the physical link for above-mentioned condition is satisfied by described virtual network requests is defined as available physical link.

Concrete, described link Calculation of Availability unit 404 calculates described each available physical link setIn the link availability of each virtual link utilizes in the link availability of each physical link and described virtual network formula include:

LC (l)=(1-α) * ln (bw (l_in))+α*Number(l_out)

Wherein α is the determined weighted value of the network size according to virtual network, bw (l_in) represent the available bandwidth of this link, Number (l_out) represent the number of links sum that two nodes of this link are connected respectively with other nodes, for physical link, other nodes described are the physical node beyond the candidate physical range of nodes corresponding to this physical node.

Concrete, described virtual network map unit 405, it is possible to including:

Link maps subelement (not shown in Fig. 4), for the virtual link l that link availability is maximum^ijMap, by virtual link l^ijCorresponding available physical link setThe physical link l that link availability is maximum_uvIt is mapped to virtual link l^ij, by this physical link l_uvA physical node n_uJoin the available physical node set of correspondenceIn, another physical node n_vJoin the available physical node set of correspondenceIn;

First judgment sub-unit (not shown in Fig. 4), for judging current available physical network node set respectivelyWithIn whether there are two physical nodes, if it is, trigger first process subelement; Otherwise trigger the second process subelement;

Described first processes subelement (not shown in Fig. 4), for finding the shortest path between said two physical node, the physical node n being newly added simultaneously_uFrom available physical network node setMiddle deletion, and judge whether described shortest path meets virtual link request amount, if triggering through subelement; Otherwise trigger the second process subelement;

Described through subelement (not shown in Fig. 4), for by virtual link l^ijWhen mapping through the described physical node n deleted from available physical network node set_u;

Described second processes subelement (not shown in Fig. 4), for by described available physical link setThe physical link l that link availability is maximum_uvFrom available physical link setMiddle deletion, and select described available physical link setTime big physical link of link availability is as the maximum physical link l of link availability_uvTrigger link maps subelement to virtual link l^ijMap;

Second judgment sub-unit (not shown in Fig. 4), for judging the virtual link l that described link availability is maximum^ijWhether it is last in virtual link, if it is, trigger node maps subelement, otherwise using next virtual link as the maximum virtual link l of link availability^ij, trigger link maps subelement;

Node maps subelement (not shown in Fig. 4), for by available physical network node setIn physical node be mapped to dummy node nⁱ;

Controller node maps subelement (not shown in Fig. 4), for by minimum for jumping figure and meet the non-mapped physical node of delay requirement and be mapped as controller node.

For device embodiment, owing to its basic skills is similar in appearance to embodiment of the method, so what describe is fairly simple, relevant part illustrates referring to the part of embodiment of the method.

It should be noted that, in this article, the relational terms of such as first and second or the like is used merely to separate an entity or operation with another entity or operating space, and not necessarily requires or imply the relation that there is any this reality between these entities or operation or sequentially. And, term " includes ", " comprising " or its any other variant are intended to comprising of nonexcludability, so that include the process of a series of key element, method, article or equipment not only include those key elements, but also include other key elements being not expressly set out, or also include the key element intrinsic for this process, method, article or equipment. When there is no more restriction, statement " including ... " key element limited, it is not excluded that there is also other identical element in including the process of described key element, method, article or equipment.

Each embodiment in this specification all adopts relevant mode to describe, between each embodiment identical similar part mutually referring to, what each embodiment stressed is the difference with other embodiments. Especially for device embodiment, owing to it is substantially similar to embodiment of the method, so what describe is fairly simple, relevant part illustrates referring to the part of embodiment of the method.

One of ordinary skill in the art will appreciate that all or part of step realizing in said method embodiment can be by the hardware that program carrys out instruction relevant and completes, described program can be stored in computer read/write memory medium, the storage medium obtained designated herein, as: ROM/RAM, magnetic disc, CD etc.

The foregoing is only presently preferred embodiments of the present invention, be not intended to limit protection scope of the present invention. All make within the spirit and principles in the present invention any amendment, equivalent replacement, improvement etc., be all contained in protection scope of the present invention.

Claims (8)

1. a mapping method of virtual network, it is characterised in that described method includes step:

When a virtual network requests arrives, according to dummy node n each in described virtual network^VCorresponding candidate physical range of nodes, is polymerized all candidate physical node set n corresponding to each dummy node^V*;

According to the candidate physical node set n corresponding to each dummy node after polymerization^v*, by the candidate collection node n of bottom physical network^V*It is attached according to the connected mode identical with bottom physical network, reconstructs bottom physical network;

Determine the available physical link in the bottom physical network after described reconstruct, by every virtual link l^ijCorresponding available physical link composition available physical link set

Calculate described each available physical link setIn the link availability of each virtual link in the link availability of each physical link and described virtual network, and respectively it is carried out descending sort according to link availability;

According to the available physical link set after each sequenceAnd virtual link, described virtual network is mapped.

2. method according to claim 1, it is characterised in that the available physical link in the described bottom physical network determining after described reconstruct, including:

Judge whether the available bandwidth of each physical link in the bottom physical network after described reconstruct meets the available CPU of two physical nodes of described virtual network requests, described each physical link and whether available stream entry meets described virtual network requests successively;

The physical link that above-mentioned condition is satisfied by described virtual network requests is defined as available physical link.

3. method according to claim 1, it is characterised in that the described each available physical link set of described calculatingIn the link availability of each virtual link utilizes in the link availability of each physical link and described virtual network formula include:

LC (l)=(1-α) * ln (bw (l_in))+α*Number(l_out)

Wherein α is the determined weighted value of the network size according to virtual network, l_inRepresent the available bandwidth of this link, Number (l_out) represent the number of links sum that two nodes of this link are connected respectively with other nodes, for physical link, other nodes described are the physical node beyond the candidate physical range of nodes corresponding to this physical node.

4. the method according to any one of claim 1-3, it is characterised in that described according to the available physical link set after each sequenceAnd virtual link, described virtual network is mapped, including:

A, the virtual link l maximum to link availability^ijMap, by virtual link l^ijCorresponding available physical link setThe physical link l that link availability is maximum_uvAllocation map is to virtual link l^ij, by this physical link l_uvA physical node n_uJoin the available physical node set of correspondenceIn, another physical node n_vJoin the available physical node set of correspondenceIn;

B, judges current available physical network node set respectivelyWithIn whether there are two physical nodes, if it is, enter step C; Otherwise, step E is entered;

C, finds the shortest path between said two physical node, the physical node n being simultaneously newly added_uFrom available physical network node setMiddle deletion, and judge whether described shortest path meets virtual link request amount, if entering step D; Otherwise enter step E;

D, by virtual link l^ijWhen mapping through the described physical node n deleted from available physical network node set_u;

E, by described available physical link setThe physical link l that link availability is maximum_uvFrom available physical link setMiddle deletion, and select described available physical link setTime big physical link of link availability is as the maximum physical link l of link availability_uvReturn step A to virtual link l^ijMap;

F, it is judged that the virtual link l that described link availability is maximum^ijWhether it is last in virtual link, if it is, perform step H, otherwise using next virtual link as the maximum virtual link l of link availability^ij, return step A;

H, by available physical network node setIn physical node be mapped to dummy node nⁱ;

I, by minimum for jumping figure and meet the non-mapped physical node of delay requirement and be mapped as controller node.

5. a virtual network mapping device, it is characterised in that described device includes:

Candidate physical node aggregation unit, for when a virtual network requests arrives, according to dummy node n each in described virtual network^VCorresponding candidate physical range of nodes, is polymerized all candidate physical node set n corresponding to each dummy node^V*;

Bottom physical network reconfiguration unit, for all candidate physical node set n corresponding to each dummy node after polymerization^V*, by the candidate collection node n of bottom physical network^V*It is attached according to the connected mode identical with bottom physical network, reconstructs bottom physical network;

Available physical link set determines unit, is used for the available physical link in the bottom physical network after determining described reconstruct, by every virtual link l^ijCorresponding available physical link composition available physical link set

Link Calculation of Availability unit, is used for calculating described each available physical link setIn the link availability of each virtual link in the link availability of each physical link and described virtual network, and respectively it is carried out descending sort according to link availability;

Virtual network map unit, for according to the available physical link set after each sequenceAnd virtual link, described virtual network is mapped.

6. device according to claim 5, it is characterised in that described available physical link set determines unit, including:

Judgment sub-unit, whether the available CPU and the available stream entry that whether meet two physical nodes of described virtual network requests, described each physical link for the available bandwidth of each physical link in the bottom physical network after judging described reconstruct successively meet described virtual network requests;

Available physical link determines subelement, and the physical link for above-mentioned condition is satisfied by described virtual network requests is defined as available physical link.

7. device according to claim 5, it is characterised in that calculate described each available physical link set in described link Calculation of Availability unitIn the link availability of each virtual link utilizes in the link availability of each physical link and described virtual network formula include:

LC (l)=(1-α) * ln (bw (l_in))+α*Number(l_out)

Wherein α is the determined weighted value of the network size according to virtual network, bw (l_in) represent the available bandwidth of this link, Number (l_out) represent the number of links sum that two nodes of this link are connected respectively with other nodes, for physical link, other nodes described are the physical node beyond the candidate physical range of nodes corresponding to this physical node.

8. the device according to any one of claim 5-7, it is characterised in that described virtual network map unit, including:

Link maps subelement, for the virtual link l that link availability is maximum^ijMap, by virtual link l^ijCorresponding available physical link setThe physical link l that link availability is maximum_uvIt is mapped to virtual link l^ij, by this physical link l_uvA physical node n_uJoin the available physical node set of correspondenceIn, another physical node n_vJoin the available physical node set of correspondenceIn;

First judgment sub-unit, for judging current available physical network node set respectivelyWithIn whether there are two physical nodes, if it is, trigger first process subelement; Otherwise trigger the second process subelement;

Described first processes subelement, for finding the shortest path between said two physical node, the physical node n being newly added simultaneously_uFrom available physical network node setMiddle deletion, and judge whether described shortest path meets virtual link request amount, if triggering through subelement; Otherwise trigger the second process subelement;

Described through subelement, for by virtual link l^ijWhen mapping through the described physical node n deleted from available physical network node set_u;

Described second processes subelement, for by described available physical link setThe physical link l that link availability is maximum_uvFrom available physical link setMiddle deletion, and select described available physical link setTime big physical link of link availability is as the maximum physical link l of link availability_uvTrigger link maps subelement to virtual link l^ijMap;

Second judgment sub-unit, for judging the virtual link l that described link availability is maximum^ijWhether it is last in virtual link, if it is, trigger node maps subelement, otherwise using next virtual link as the maximum virtual link l of link availability^ij, trigger link maps subelement;

Node maps subelement, for by available physical network node setIn physical node be mapped to dummy node nⁱ;

Controller node maps subelement, for by minimum for jumping figure and meet the non-mapped physical node of delay requirement and be mapped as controller node.