CN104243263A - Online hybrid virtual network mapping method - Google Patents

Abstract

The invention discloses an online hybrid virtual network mapping method. The method includes the steps that an arrived hybrid virtual network request is divided, so that a multicast virtual network request and a unicast virtual network request are acquired and mapped; in the mapping process of the unicast virtual network request, a virtual link with overlapped virtual nodes in the multicast virtual network request and the unicast virtual network request serving as a source node and a destination node is preferably mapped, and then other virtual nodes and other virtual links are mapped. According to the method, the hybrid virtual network request containing the unicast virtual network request and the multicast virtual network request can be processed, and the method is suitable for traditional unicast virtual network requests or traditional multicast virtual network requests as well and is wide in application range.

Description

A kind of on-line mixing mapping method of virtual network

Technical field

The invention belongs to virtual network mapping techniques field, more specifically say, relate to a kind of on-line mixing mapping method of virtual network.

Background technology

Network virtual is turned to and solves current internet and to ossify the technological means of problem, receives the extensive concern of domestic and international future network area research in recent years.One of advantage of network virtualization supports that the network architecture of multiple isomery shares physical infrastructure.Its essence of network virtualization technology on a public physical network, runs multiple virtual net by abstract, distribution, isolation mech isolation test independently, thus can carry out best Resourse Distribute and scheduling selectively.

The object of network virtualization is exactly realize extensively sharing of distributed virtual resource, and therefore virtual resource maps is the critical function that network virtualization technology needs to realize.Virtual resource mapping algorithm is as one of the key issue of network virtualization technology, it achieve the process reasonably mapped to by the virtual network requests of user on the physical resource of bottom physical network, wherein how efficient allocation physical network resource, to meet link bandwidth and the joint behavior requirement of each virtual network, is the key of virtual resource mapping problems.

The forms such as clean culture, multicast, broadcast, mixing virtual network are had in internetwork communication.Wherein clean culture and multicast are widely used in the application of the real-time of many needs high QoS, but in virtual network, existing most virtual resource mapping algorithm only to unicast service or multicast service effective.Single unicast or multicast mapping algorithm is not also suitable for the situation mixing virtual network usually.

Existing virtual network mapping algorithm realizes according to heuritic approach mostly.Heuritic approach is the common method solving virtual resource mapping problems, and heuritic approach carrys out the result of bootstrap algorithm by definition heuristic factor, the function of final implementation algorithm.Comprise in algorithm node resource distribute and link circuit resource distribute two parts.Node resource distribution refers to: according to the constraints of dummy node, by the Resourse Distribute of bottom layer node to dummy node.Link circuit resource distributes and refers to: according to the constraints of the source node of virtual link and the mapped bottom layer node of destination node and virtual link, by the Resourse Distribute of bottom-layer network bottom link or many bottom links to virtual link.Several heuritic approaches for virtual resource mapping problems proposed at present are much based on clean culture or based on the single situation in multicast.

Have a lot about the research of online mapping method of virtual network in network virtualization, A sliding window approach based heuristic algorithm for the online stochastic VN mapping (StoVNM) problem (w-StoVNM) algorithm is exactly a kind of method that online virtual network maps.The method, when the node of bottom-layer network and bandwidth resource allocation being given each virtual network requests dynamically arrived, in order to more effectively utilize bottom-layer network resource, the method uses load balancing to guide the mapping of virtual network requests.Supposing that link bandwidth resource request is dynamic change in the method, employing the random multiplex strategy of link bandwidth resource to save bandwidth resources.

Although said method can realize the mapping of online virtual network, but this method proposes for clean culture virtual network mapping problems.In actual applications, there is a large amount of mixing virtual network (Hybrid Virtual Network, HVN) ask, the existing clean culture virtual network of mixing virtual network requests (Unicast Virtual Network, the characteristic of UVN) asking, there is again multicast virtual network request (Multicast Virtual Network, MVN) characteristic, but said method is only suitable for clean culture virtual network mapping problems, and some particularity constraint of multicast virtual network mapping in mixing virtual network requests cannot be taken into account, such as delay variation, thus mixing virtual network mapping problems can not be applicable to.

For multicast virtual network mapping problem, also there is the research of a lot of correlation method.Virtual multicast service-oriented network subject to delay and delay variation constraints mapping algorithm (VMNDDVCM) algorithm is a kind of mapping method of common solution multicast virtual network, the method has considered the particularity of multicast virtual network, introduce the time delay of multicast network and the characteristic of delay variation, the delay variation solved in mapping process by introducing window sliding mechanism retrains, enumeration strategy is adopted to find the optimum multicast tree of satisfied constraint to complete mapping, ensure that optimum mapping cost.

Although said method can realize multicast virtual network mapping, virtual multicast network is mainly used in supporting many real-times with different performance requirements or interactively application, as video conference, distributed data base copy and online game etc.These application require that destination must receive packet (namely having delay constraint) within the time of specifying, and the delay variation simultaneously receiving packet between each destination should be minimum (namely having time delay jitter restriction).But not delay variation constraint in clean culture virtual network, map if map clean culture virtual network by multicast virtual network mapping method, usual mapping result is not optimum.Therefore, the mapping method of multicast virtual network is not suitable for the mapping of clean culture virtual network usually.And mix the characteristic of the existing multicast virtual network of virtual network, have again the characteristic of clean culture virtual network, therefore, the mapping method of multicast virtual network is not suitable for mixing virtual network.

Summary of the invention

The object of the invention is to overcome the deficiencies in the prior art, a kind of on-line mixing mapping method of virtual network is provided, realize the mapping of mixing virtual network layer physical network on earth.

For achieving the above object, on-line mixing mapping method of virtual network of the present invention comprises the following steps:

S1: the mixing virtual network requests queue that note arrives is ArrivedHVN, the mixing virtual network requests set that initialization gets clogged

S2: judge whether ArrivedHVN is empty, if be empty, the mapping result exporting mapped successful mixing virtual network requests in mixing virtual network requests queue ArrivedHVN and the mixing virtual network requests set HVN got clogged _blo, otherwise enter step S3;

S3: judge currently whether there is matured mixing virtual network requests, if had, recovers bottom-layer network resource, enters step S4, otherwise directly enter step S4;

S4: take out a request HVN from mixing virtual network requests queue ArrivedHVN, is isolated into multicast virtual network MVN request and clean culture virtual network UVN asks, and separation method comprises the following steps:

S4.1: initialization multicast virtual network link set E _mV, multicast virtual set of network nodes N _mV, clean culture virtual network link set E _uVwith clean culture virtual network node set N _uVbe empty set;

According to class indication, S4.2: the every bar link in traversal mixing virtual network requests queue ArrivedHVN, determines whether this link belongs to multicast virtual network, if so, this link is added multicast virtual network link set E _mV, otherwise link is added clean culture virtual network link set E _uV;

S4.3: traversal multicast virtual network link set E _mVin every bar virtual link, if the source node of this virtual link or destination node be not at multicast virtual set of network nodes N _mVin, then source node or destination node are added multicast virtual set of network nodes N _mV;

S4.4: traversal clean culture virtual network link set E _uVin every bar virtual link, if there is not clean culture virtual network node set N in the source node of this virtual link or destination node _uVin, then source node or destination node are added multicast virtual set of network nodes N _uV;

S5: be separated multicast virtual network link set E corresponding to the multicast virtual network request that obtains according to step S4 _mVwith multicast virtual set of network nodes N _mV, virtual link and dummy node are mapped, if map successfully, preserve mapping scheme, enter step S6, otherwise enter step S7;

S6: the multicast virtual set of network nodes N that step S4 is obtained _mVwith clean culture virtual network node set N _uVthe node set of middle overlap is designated as N _mapped, from clean culture virtual network link set E _uVin choose to gather N _mappedinterior joint is the virtual link of source node and destination node, and the set of these links is designated as E, first maps, then to multicast virtual set of network nodes N the virtual link in set E _mVwith clean culture virtual network node set N _uVin remaining dummy node and virtual link map, if clean culture virtual network requests maps successfully, preservation mapping scheme, enters step S8, otherwise enters step S7;

S7: this request is added set HVN _bloeven, HVN _blo=HVN _blo∪ HVN, enters step S8;

S8: this request is deleted from mixing virtual network requests queue ArrivedHVN, even ArrivedHVN=ArrivedHVN-HVN, returns step S2.

On-line mixing mapping method of virtual network of the present invention, the mixing virtual network requests of arrival is separated, obtain multicast virtual network request and clean culture virtual network requests, respectively multicast virtual network request and clean culture virtual network requests are mapped, when carrying out clean culture virtual network and mapping, preferentially map for the virtual link of source node and destination node with overlapping virtual node in multicast virtual network request and clean culture virtual network requests, then other dummy nodes and virtual link are mapped.The present invention can pack processing containing the mixing virtual network requests of clean culture virtual network requests and multicast virtual network request, and be also applicable for traditional clean culture virtual network requests or multicast virtual network request, the scope of application is very wide.

Accompanying drawing explanation

Fig. 1 is the workflow schematic diagram of on-line mixing mapping method of virtual network of the present invention;

Fig. 2 is that HVN request is separated exemplary plot; Wherein, Fig. 2 (a) is that HVN asks exemplary plot, and Fig. 2 (b) is separated the MVN request obtained; Fig. 2 (c) is separated the UVN request obtained;

Fig. 3 is the exemplary plot that in Fig. 2, MVN request maps;

Fig. 4 is the exemplary plot that in Fig. 2, UVN request maps;

Fig. 5 is a kind of embodiment flow chart that MVN request maps;

Fig. 6 is a kind of embodiment flow chart that UVN request maps.

Embodiment

Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described, so that those skilled in the art understands the present invention better.Requiring particular attention is that, in the following description, when perhaps the detailed description of known function and design can desalinate main contents of the present invention, these are described in and will be left in the basket here.

Embodiment

Fig. 1 is the workflow schematic diagram of on-line mixing mapping method of virtual network of the present invention.As shown in Figure 1, the present invention's mixing mapping method of virtual network comprises the steps:

S101:HVN asks to arrive:

The mixing virtual network requests queue that note arrives is ArrivedHVN, the mixing virtual network requests set that initialization gets clogged

S102: judge whether ArrivedHVN is empty, if be empty, enter step 103, otherwise enters step S104.

S103: the mapping result exporting mapped successful mixing virtual network requests in mixing virtual network requests queue ArrivedHVN and the mixing virtual network requests set HVN got clogged _blo, map and terminate.

S104: judge currently whether there is matured mixing virtual network, if had, enter step S105, otherwise enter step S106.

S105: recover bottom-layer network resource, enter step S106.

S106: take out a request HVN from mixing virtual network requests queue ArrivedHVN, be isolated into MVN request and UVN request:

For convenience of description, virtual network requests (HVN request) will be mixed and be expressed as undirected weighted graph G _hV=(N _hV, E _hV), wherein N _hV={ v ₁, v ₂..., v _i..., v _a, represent the dummy node set in HVN request, A represents dummy node quantity, each dummy node v _iattribute comprise node resource and require c _i, E _hV={ e ₁, e ₂...., e _j..., e _b, represent the virtual link set in HVN request, B represents virtual link quantity, each virtual link e _jattribute comprise link circuit resource and require x _j, delay requirement y _jz is required with delay variation _j.In the present embodiment, employing delay variation requires the class indication as multicast virtual network request (MVN request) and clean culture virtual network requests (UVN request), namely only has MVN to ask just have delay variation requirement.In actual applications, class indication also can be arranged as required.Due in mixing virtual network, multicast virtual network and all each characteristic of having oneself by oneself of clean culture virtual network part, so in the present invention when mapping mixing virtual network, first mixing virtual network is separated into multicast virtual network and clean culture virtual network two parts (possible two parts exist simultaneously, also may only have a part).

Fig. 2 is that HVN request is separated exemplary plot.As shown in Fig. 2 (a), dummy node a, b, c, virtual link (a, b), (a, c), being dummy node and the virtual link of unicast service, is again dummy node and the virtual link of multicast service, so dummy node a, b, c, the characteristic of virtual link (a, b), (a, c) existing unicast service, have again the characteristic of multicast service, and remaining dummy node and virtual link only belong to unicast service.So whole request is exactly the virtual network requests of a mixing.Numeral node resource requirement in square frame, when node line existing 3 groups of numerals, then represents link circuit resource requirement, delay requirement and delay variation requirement respectively, when there is 2 groups of numerals, then represents that link circuit resource requires and delay requirement respectively.MVN request, for being separated the MVN request obtained, is configured to undirected weighted graph G by Fig. 2 (b) _mV=(N _mV, E _mV), wherein N _mVrepresent the node set of MVN request, E _mVrepresent the link set of MVN request.Specifically, single MVN request can be expressed as two-layer tree structure, and as shown in Fig. 2 (b), its interior joint a is root dummy node, b and c is leaf dummy node.UVN request, for being separated the UVN request obtained, is configured to undirected weighted graph G by Fig. 2 (c) _uV=(N _uV, E _uV), wherein N _uVrepresent the node set of UVN request, E _uVrepresent the link set of UVN request.

The separation method mixing virtual network requests in the present invention is:

S6.1: initialization multicast virtual network link set E _mV, multicast virtual set of network nodes N _mV, clean culture virtual network link set E _uVwith clean culture virtual network node set N _uVbe empty set.

According to class indication, S6.2: the every bar virtual link in traversal mixing virtual network requests queue ArrivedHVN, determines whether this virtual link belongs to multicast virtual network, if so, this link is added multicast virtual network link set E _mV, otherwise virtual link is added clean culture virtual network link set E _uV.

In the present embodiment, class indication, for whether there is delay variation requirement, exists and namely belongs to multicast virtual network, do not exist and namely belong to clean culture virtual network.Visible multicast virtual network link set E _mVthe attribute of middle virtual link comprises that link circuit resource requires, delay requirement and delay variation requirement, clean culture virtual network link set E _uVthe attribute of middle virtual link comprises link circuit resource and requires and delay requirement.

S6.3: the traversal step S302 multicast virtual network link set E obtained _mVin every bar virtual link, if the source node of this virtual link or destination node be not at multicast virtual set of network nodes N _mVin, then source node or destination node are added multicast virtual set of network nodes N _mV.

S6.4: traversal step S302 clean culture virtual network link set E _uVin every bar virtual link, if there is not clean culture virtual network node set N in the source node of this virtual link or destination node _uVin, then source node or destination node are added multicast virtual set of network nodes N _uV.

As shown in Figure 2 in HVN request, be separated in the MVN request obtained, node set G _mVcomprise dummy node a, b, c, link set E _mVcomprise virtual link (a, b), (a, c).In UVN request, node set G _uVcomprise dummy node b, c, d, e, link set E _mVcomprise virtual link (b, c), (c, d), (d, e), (b, d).

The separation of HVN request can be realized according to above method, next the MVN obtained separation request and UVN request are mapped respectively.Because multicast virtual network is mainly used in supporting manyly have the real-time of different performance requirements or interactively application, as video conference, distributed data base copy and online game etc.These application require that destination must receive packet (namely having delay constraint) within the time of specifying, the delay variation simultaneously receiving packet between each destination should be minimum, there is weak synchronous requirement (namely having time delay jitter restriction) time that in the distribution procedure of i.e. information, multicast accepts packet for each destination node, so the constraint of multicast virtual network is stronger in the process of information interaction, so should first consider to map multicast virtual network request part in mapping process.

S107:MVN asks to map:

Multicast virtual network link set E corresponding to the multicast virtual network request that obtains is separated according to step S106 _mVwith multicast virtual set of network nodes N _mV, virtual link and dummy node are mapped, if map successfully, enter step S108, otherwise enter step S109.

Fig. 3 is the exemplary plot that in Fig. 2, MVN request maps.In Fig. 3 (b), in square frame, left side numeral is the available resources total amount of node, and digits right is unit-node resources costs, and 3 numerals on link are respectively available link total resources, unit link circuit resource cost and chain-circuit time delay from left to right.

S108:UVN asks to map:

Ask separating resulting from HVN, in MVN request and UVN request, have overlapping dummy node, and have mapped these dummy nodes in MVN request, therefore do not need to map again in UVN request.And have mapped due to these overlapping virtual nodes, simultaneously relatively little with the selection possibility of these overlapping virtual nodes virtual link that is source node and destination node in UVN request, therefore preferentially these virtual links are mapped when UVN request maps, be mapped to power to improve.Its concrete grammar is:

The multicast virtual set of network nodes N that step S4 is obtained _mVwith clean culture virtual network node set N _uVthe dummy node set of middle overlap is designated as N _mapped, i.e. N _mapped=N _uV∩ N _mV, from clean culture virtual network link set E _uVin choose to gather N _mappedmiddle dummy node is the virtual link of source node and destination node, and the set of these virtual links is designated as E, first maps, then to multicast virtual set of network nodes N the virtual link in set E _mVwith clean culture virtual network node set G _uVin remaining dummy node and virtual link map, if clean culture virtual network requests maps successfully, enter step S110, otherwise enter step S109.Fig. 4 is the exemplary plot that in Fig. 2, UVN request maps.

In S109:MVN request and UVN request, any one does not map successfully, namely illustrates that whole HVN request does not map successfully, so this HVN request is added set HVN _bloeven, HVN _blo=HVN _blo∪ HVN, recovers the bottom-layer network resource that this HVN asks to take in mapping process, enters step S110.

S110: no matter whether HVN request maps successfully, deletes this request from mixing virtual network requests queue ArrivedHVN, even ArrivedHVN=ArrivedHVN-HVN, returns step S102 and continues to map next one request.

In actual applications, the concrete mapping method of MVN request and UVN request can be selected, as required normally at the mapping scheme meeting Choose for user cost minimization under related constraint condition.

Because MVN request can be described as the structure of two-layer tree, and root dummy node is the dummy node of largest contiguous degree in all MVN dummy nodes.Therefore the method that in the present embodiment, MVN request maps is: first map root dummy node, and then map leaf dummy node.While each leaf dummy node of mapping, find virtual link to be mapped to the path candidate of bottom-layer network, finally complete mapping according to delay variation window adjusting mapping path again.Fig. 5 is a kind of embodiment flow chart that MVN request maps.As shown in Figure 5, the concrete steps that in the present embodiment, MVN request maps comprise:

S501: initialization set UMN ^s=N ^sand UMN _v=N _mV, wherein N ^s={ n ₁, n ₂..., n _k..., n _crepresenting the node set of bottom-layer network, C represents bottom layer node quantity.

S502: map root node:

Root dummy node v is found, traversal UMN from MVN request ^sin each bottom layer node n _k, calculate and root node v be mapped to bottom layer node n _kon expense Cost (v → n _k), select the bottom layer node n that minimal-overhead is corresponding _smap root dummy node v, these mapping relations are updated to MVN mapping scheme M _min, make UMN _v=UMN _v-v and UMN ^s=UMN ^s-n _k.

In the present embodiment, expense Cost (v → n _k) computing formula be:

Cost(v→n _k)＝(p(n _k)+(MC-Con(n _k))*ε(v)+1/R _n(n _k)+1/R _e(AdjLink(n _k)) (1)

Wherein, p (n _k) represent bottom layer node n _kthe unit cost of resource, Con (n _k)=| Adj (n _k) | represent bottom layer node n _kadjacent degree, MC is the value that in all bottom layer node, adjacent degree is maximum, and ε (v) represents the node resource requirement of the root dummy node v that MVN asks, R _n(n _k) represent bottom layer node n _ksurplus resources, AdjLink (n _k) represent bottom layer node n _kadjacent link set, so R _e(AdjLink (n _k)) represent bottom layer node n _kthe remaining resource capacity sum of adjacent link.P (n in formula _k) effect be that root dummy node is directed to the low node of those bottom layer node costs, MC-Con (n _k) effect be that root dummy node is directed to the large bottom layer node of those adjacent degrees, 1/R _n(n _k) and 1/R _e(AdjLink (n _k) be used to do load balancing, in order to root dummy node being directed to those bottom layer node that residue node resources are many and residue link circuit resource sum that is node adjacency link is many.The virtual cost of such unit is lower, the surplus resources of node is more, the node that residue link circuit resource sum is larger, adjacent degree is larger of node adjacency link more easily becomes the mapping node of root dummy node, so just has more selection to during the link of root dummy node mapping other leaf dummy node.

S503: preliminary mapping is carried out to leaf node and path:

From UMN _vmiddle taking-up dummy node v _p, by dummy node v _pbe mapped to UMN ^sin each bottom layer node n _k, and according to node resource requirement, root dummy node v and dummy node v _pbetween link circuit resource to require and chain-circuit time delay requirement is found and is connected n _sand n _kcandidate's bottom path calculate dummy node v _pbe mapped to UMN ^sin each bottom layer node n _kcost Cost (v _p→ n _k), if can not find candidate's bottom path, then make Cost (v _p→ n _k)=∞.When mapping, can first select node resource requirement large, or and root dummy node between link circuit resource require that large dummy node maps, be mapped to power to improve.

The constraint formulations that node resource requires is:

R _n(n _k)≥ε(v _p) (2)

Wherein, R _n(n _k) represent bottom layer node n _kresidue node resource, ε (v _p) represent dummy node v _pnode resource demand.

In the present embodiment, when carrying out link circuit resource and mapping, adopt the random multiplex strategy of link circuit resource.Suppose link resource needs x _jdynamic change, and followed normal distribution distribution and as j ≠ j ', x _jand x _{j '}separate.Therefore, the link maps of HVN can be modeled as a random multiplexing model of link circuit resource.When the link of mapping HVN is to bottom-layer network link, bottom-layer network link is necessary for the certain link bandwidth capacity of the link assignment of each HVN, and the size of the link bandwidth demand of each HVN exceedes the probability α ∈ (0,1) that the probability of the bottom-layer network link bandwidth capacity of distribution can not be given more than.For a given probability α, from the characteristic of normal distribution, probability P [x > μ+Φ ^-1(1-α) σ]=α.And if only if μ+Φ ^-1(1-α) σ≤b (e _s) time, according to P [x > b (e _s)]≤α, wherein, Φ ^-1for the inverse function of the cumulative distribution function Φ of normal distribution.At this, make β=Φ ^-1(1-α), for a bottom-layer network link, each is mapped in this bottom-layer network link e _son the capacity requirement of HVN link be μ _j+ β σ _j, and meet μ _j+ β σ _j≤ b (e _s), b (e _s) represent bottom link e _savailable bandwidth resources.Therefore, when not using the random multiplex strategy of link circuit resource, the total capacity demand being mapped in many HVN links on this bottom-layer network link is that the capacity requirement of each is directly added, and is represent and be mapped to bottom link e _son virtual link set.But from the characteristic of normal distribution, have additivity when two normal distributions are separate, namely many HVN link maps are also followed normal distribution distributions to total bandwidth resources demand of a bottom-layer network link, and its average is variance is at this moment the total capacity demand being mapped in the HVN link on this bottom-layer network link becomes here it is the random multiplex strategy of link circuit resource.

According to the random multiplex strategy of link circuit resource, root dummy node v and dummy node v _pbetween link circuit resource require can be expressed as:

virtual link e _pbefore, bottom link e _sjust occupied resource capacity.

The constraint formulations of delay requirement is:

$D\left(p_{e_p}\right)\≤C_D---\left(4\right)$

Wherein, represent bottom path time delay, C _drepresent maximum link delay constraint.

In the present embodiment, Cost (v _p→ n _k) computing formula be:

Cost(v _p→n _k)＝CNn _k+CPn _k (5)

Wherein, CNn _krepresent the cost of node resource, CPn _krepresent the cost of bandwidth resources, CNn _kand CPn _kcan according to formulae discovery below:

CNn _k＝p(n _k)*ε(v _p) (6)

$\begin{array}{c}{\mathrm{CPn}}_k=\underset{e_s\∈p_{e_i}}{\mathrm{\Σ}}p\left(e_s\right)*((\left({\mathrm{\Σ}}_{m\∈D_{e_s}}{\mathrm{\μ}}_m\right)+{\mathrm{\μ}}_p+\mathrm{\β}\sqrt{\left({\mathrm{\Σ}}_{m\∈D_{e_s}}{\mathrm{\σ}}_m^2\right)+{\mathrm{\σ}}_p^2})\\ -({\mathrm{\Σ}}_{m\∈D_{e_s}}{\mathrm{\μ}}_m+\mathrm{\β}\sqrt{\left({\mathrm{\Σ}}_{m\∈D_{e_s}}{\mathrm{\σ}}_m^2\right)})\end{array}---\left(7\right)$

Wherein, connect n _sand n _kcandidate's bottom path, e _pconnect v and v _pvirtual link. random multiplexing rear bottom-layer network link e _soccupied total resources, two parts subtract each other the resource being the actual deduction of this mapping.

S504: select minimum Cost (v _p→ n _k), if min is (Cost (v _p→ n _k))=∞, enter step S510, otherwise enter step S505.

S505: by min (Cost (v _p→ n _k)) corresponding bottom layer node is as dummy node v _pmapping node, these mapping relations are updated to MVN mapping scheme M _min, make UMN _v=UMN _v-v _pand UMN ^s=UMN ^s-n _k, using the bottom path of correspondence as root dummy node v and dummy node v _pbetween the mapping path of virtual link, add mapping path set P ^*.

S506: if return step S503; Otherwise, enter step S507.

S507: judge mapping path set P ^*in the time delay in all bottom paths whether meet delay variation requirement, if met, by mapping path set P ^*in mapping relations be updated to MVN mapping scheme M _min, enter step S507, otherwise bottom path is adjusted, make it meet delay variation requirement, if there is no meet the mapping path set of delay variation requirement, enter step S510, otherwise by the mapping path set after adjustment in mapping relations be updated to MVN mapping scheme M _min, enter step S508.

Because the delay variation of mapping path can not be greater than C _dV, therefore must check the delay variation of each path candidate, if do not meet delay variation requirement, just must adjust path candidate.The constraint formula that delay variation requires is:

$|P_{e_p}-P_{e_q}|\≤C_{\mathrm{DV}},\∀e_p,e_q\∈E_{\mathrm{MV}},$ And e _p≠ e _q(8)

According to above formula, each suitable bottom path known all should meet one of formula below:

$\min \left\{\underset{e\∈p_{e_p}}{\mathrm{\Σ}}d\left(e\right)\right\}\≤\underset{e\∈p_{e_p}}{\mathrm{\Σ}}d\left(e\right)\≤\min \left\{\underset{e\∈p_{e_p}}{\mathrm{\Σ}}d\left(e\right)\right\}+C_{\mathrm{DV}},p_{e_p}\∈P^{*}---\left(9\right)$

Or:

$\max \left\{\underset{e\∈p_{e_p}}{\mathrm{\Σ}}d\left(e\right)\right\}-C_{\mathrm{DV}}\≤\underset{e\∈p_{e_p}}{\mathrm{\Σ}}d\left(e\right)\≤\max \left\{\underset{e\∈p_{e_p}}{\mathrm{\Σ}}d\left(e\right)\right\},p_{e_p}\∈P^{*}---\left(10\right)$

Wherein represent the minimal time delay in all candidate's bottom paths, represent the maximum delay in all candidate's bottom paths, C _dVrepresent link maximum delay jitter restriction.According to formula (9) as the Rule of judgment prolonging jitter restriction, when can not meet the path of delay constraint condition between existence with the path of minimal time delay, the path that time delay must be looked for less replaces original path, and the alternative route obviously looking for time delay less is very difficult.And when selecting the constraints of formula (10) instead formula (8), when certain paths does not meet formula (10), the time delay in this path is just less than this is that the path just needing to look for time delay larger replaces original path, relatively with look for the path that a time delay is little, the path looking for time delay larger is very easy.Therefore, time delay window W=[D is set _max-C _dV, D _max], each selected path being carried out to the judgement of delay constraint, not only effectively can judge and find out the set of paths meeting delay constraint condition, also greatly reducing in formula (8) comparing brought complexity between path between two.Judge all mapping path according to time delay window, if there is the path that path does not meet time delay window, then find K paths by K-shortestpaths method, then select one to meet time delay window shortest path and replace original path, then upgrade M _m.

S508: judge that whether bottom-layer network resource is enough, namely according to MVN mapping scheme M _mpre-deduction bottom-layer network resource, if bottom-layer network resource residual amount is greater than 0 after deduction, enters step S509, otherwise enters step S510.When deducting bottom link circuit resource, the random multiplex strategy of link circuit resource also can be adopted.

S509: map successfully, preserves MVN mapping scheme M _m.

S510:MVN request maps unsuccessfully.

When deducting bottom-layer network resource, the random multiplex strategy of bottom link can be adopted equally to the deduction of bottom link circuit resource.

Fig. 6 is a kind of embodiment flow chart that UVN request maps.As shown in Figure 6, in the present embodiment, the concrete steps that UVN request maps comprise:

S601: initialization N _mapped=N _uV∩ N _mV, namely try to achieve multicast virtual set of network nodes N _mVwith clean culture virtual network node set N _uVthe dummy node set of middle overlap, initialization set UMN ^s=N ^s, UMN _v=N _uV-N _mapped, from clean culture virtual network link set E _uVin choose to gather N _mappedinterior joint is the virtual link of source node and destination node, and the set of these virtual links is designated as E, according to the mapping scheme of MVN request, will gather N _mappedin node mapping result be updated to UVN mapping scheme M _u.

S602: judge whether if so, illustrate that UVN request asks do not have overlapping virtual node with MVN, that does not also carry out the preferential link mapped with respective virtual node for source node and destination node, needs, therefore enters step S606, otherwise enters step S603.

S603: if , enter step S604, otherwise enter step S606;

S604: take out a virtual link e from set E _q, map, map, if be successfully mapped to bottom path according to link circuit resource requirement and delay requirement enter step S605, otherwise enter step S612.

Similarly, when carrying out link maps, link that also can be first large to link resource needs maps.

S605: upgrade E=E-e _q, return step S603.

S606: if enter step S607, otherwise enter step S611.

S607: from UMN _vmiddle selection one and N _mappedthe dummy node v that middle dummy node is adjacent _g, by dummy node v _gwith N _mappedlink between middle adjacent node puts into set E.

S608: node and link preliminary mapping:

Maps virtual node v _gwith Article 1 virtual link e in set E _h, attempt dummy node v _gbe mapped to UMN ^sin each bottom layer node n _k, find e according to link circuit resource requirement, delay requirement _hcandidate's bottom path calculate maps virtual node v _gto bottom layer node n _kexpense Cost (v _g→ n _k), if the candidate's bottom path do not met the demands then make Cost (v _g→ n _k)=∞.

S609: select minimum Cost (v _g→ n _k), if min is (Cost (v _g→ n _k))=∞, enter step S612, otherwise enter step S610.

S610: by min (Cost (v _g→ n _k)) corresponding bottom layer node is as dummy node v _gmapping node, these mapping relations are updated to UVN mapping scheme M _uin, upgrade bottom-layer network resource, make UMN _v=UMN _v-v _p, UMN ^s=UMN ^s-n _k, N _mapped=N _mapped+ v _g, E=E-e _h, return step S603.

S611: export UVN mapping scheme M _u.

S612: map and terminate, UVN request maps unsuccessfully.

Similarly, in the link maps of UVN request, also can use the random multiplex strategy of link circuit resource.

In actual applications, the present invention's mixing mapping method of virtual network can be deployed on the key-course of SDN (Software Defined Network, software virtualization) network-based control router.SDN control router can dispatch self with control and management function collect the whole network information, obtain all node resource situations in network, and the resource of link, the information such as time delay.The topology of the whole network and corresponding resource information just can be obtained by this this router of centralized control mode.

When there being virtual mixed network service to arrive, SDN controls the whole network information that router can be grasped according to oneself, and the mixing mapping method of virtual network of scheduling deployment on its key-course, calculates map information.The node tasks of respective virtual mixed service is distributed to mapping node, and sends corresponding Work route (i.e. the link maps situation of virtual hybrid network), carry out the actual mapping of mixing virtual network by this way.After mapping completes, deduct corresponding node and link circuit resource by this control router, cost and benefit calculating can also be carried out simultaneously, and feed back to operator.

When SDN router receives virtual mixed service request, initialization its own system information, namely obtains the whole network information and the virtual mixed network service arrived is added task queue.Call the mixing mapping method of virtual network disposed in advance and complete mapping, and preserve mapping result renewal system mode (comprising the calculating of resource consumption and mapping cost).Whether there is according to the method search the result more optimized, carry out mappings and move and upgrade corresponding information, preservation mapping result return mapping cost.

On-line mixing mapping method of virtual network of the present invention, different from traditional mapping method of virtual network for clean culture virtual network requests or the single situation of multicast virtual network request, can pack processing containing the mixing virtual network requests of clean culture virtual network requests and multicast virtual network request, and be also applicable for traditional clean culture virtual network requests or multicast virtual network request, the scope of application is very wide.

Although be described the illustrative embodiment of the present invention above; so that those skilled in the art understand the present invention; but should be clear; the invention is not restricted to the scope of embodiment; to those skilled in the art; as long as various change to limit and in the spirit and scope of the present invention determined, these changes are apparent, and all innovation and creation utilizing the present invention to conceive are all at the row of protection in appended claim.

Claims (5)

1. an on-line mixing mapping method of virtual network, is characterized in that, comprises the following steps:

S1: the mixing virtual network requests queue that note arrives is ArrivedHVN, the mixing virtual network requests set that initialization gets clogged

S2: judge whether ArrivedHVN is empty, if be empty, the mapping result exporting mapped successful mixing virtual network requests in mixing virtual network requests queue ArrivedHVN and the mixing virtual network requests set HVN got clogged _blo, otherwise enter step S3;

S3: judge currently whether there is matured mixing virtual network requests, if had, recovers bottom-layer network resource, enters step S4, otherwise directly enter step S4;

S4: take out a request HVN from mixing virtual network requests queue ArrivedHVN, is isolated into multicast virtual network MVN request and clean culture virtual network UVN asks, and separation method comprises the following steps:

S4.1: initialization multicast virtual network link set E _mV, multicast virtual set of network nodes N _mV, clean culture virtual network link set E _uVwith clean culture virtual network node set N _uVbe empty set;

According to class indication, S4.2: the every bar link in traversal mixing virtual network requests queue ArrivedHVN, determines whether this link belongs to multicast virtual network, if so, this link is added multicast virtual network link set E _mV, otherwise link is added clean culture virtual network link set E _uV;

S4.3: traversal multicast virtual network link set E _mVin every bar virtual link, if the source node of this virtual link or destination node be not at multicast virtual set of network nodes N _mVin, then source node or destination node are added multicast virtual set of network nodes N _mV;

S4.4: traversal clean culture virtual network link set E _uVin every bar virtual link, if there is not clean culture virtual network node set N in the source node of this virtual link or destination node _uVin, then source node or destination node are added multicast virtual set of network nodes N _uV;

S5: be separated multicast virtual network link set E corresponding to the multicast virtual network request that obtains according to step S4 _mVwith multicast virtual set of network nodes N _mV, virtual link and dummy node are mapped, if map successfully, preserve mapping scheme, enter step S6, otherwise enter step S7;

S6: the multicast virtual set of network nodes N that step S4 is obtained _mVwith clean culture virtual network node set N _uVthe node set of middle overlap is designated as N _mapped, from clean culture virtual network link set E _uVin choose to gather N _mappedinterior joint is the virtual link of source node and destination node, and the set of these links is designated as E, first maps, then to multicast virtual set of network nodes N the virtual link in set E _mVwith clean culture virtual network node set N _uVin remaining dummy node and virtual link map, if clean culture virtual network requests maps successfully, preservation mapping scheme, enters step S8, otherwise enters step S7;

S7: this request is added set HVN _bloeven, HVN _blo=HVN _blo∪ HVN, enters step S8;

S8: this request is deleted from mixing virtual network requests queue ArrivedHVN, even ArrivedHVN=ArrivedHVN-HVN, returns step S2.

2. on-line mixing mapping method of virtual network according to claim 1, in described step S5, during multicast virtual network MVN asks, the mapping method of virtual link and dummy node comprises the following steps:

S5.1: initialization set UMN ^s=N ^sand UMN _v=N _mV, wherein N ^s={ n ₁, n ₂..., n _k..., n _crepresenting the node set of bottom-layer network, C represents bottom layer node quantity;

S5.2: find root dummy node v from MVN request, traversal UMN ^sin each bottom layer node n _k, calculate and root dummy node v be mapped to bottom layer node n _kon expense Cost (v → n _k), select the bottom layer node n that minimal-overhead is corresponding _smap root node v, these mapping relations are updated to MVN mapping scheme M _min, make UMN _v=UMN _v-v and UMN ^s=UMN ^s-n _k;

S5.3: from UMN _vmiddle taking-up dummy node v _p, by dummy node v _pbe mapped to UMN ^sin each bottom layer node n _k, and according to node resource requirement, root dummy node v and dummy node v _pbetween link circuit resource to require and chain-circuit time delay requirement is found and is connected n _sand n _kcandidate's bottom path calculate dummy node v _pbe mapped to UMN ^sin each bottom layer node n _kcost Cost (v _p→ n _k), if the candidate's bottom path do not met the demands, then make Cost (v _p→ n _k)=∞;

S5.4: select minimum Cost (v _p→ n _k), if min is (Cost (v _p→ n _k))=∞, MVN request maps unsuccessfully, otherwise by min (Cost (v _p→ n _k)) corresponding bottom layer node is as dummy node v _pmapping node, these mapping relations are updated to MVN mapping scheme M _min, make UMN _v=UMN _v-v _pand UMN ^s=UMN ^s-n _k, using the bottom path of correspondence as root dummy node v and dummy node v _pbetween the mapping path of virtual link, add mapping path set P ^*;

S5.5: if return step S5.3; Otherwise, enter step S5.6;

S5.6: judge mapping path set P ^*in the time delay in all bottom paths whether meet delay variation requirement, if met, by mapping path set P ^*in mapping relations be updated to MVN mapping scheme M _min, enter step S5.7, otherwise adjust bottom path, make it meet delay variation requirement, if there is no meet the mapping path set of delay variation requirement, MVN request maps unsuccessfully, otherwise by the mapping path set after adjustment in mapping relations be updated to MVN mapping scheme M _min, enter step S5.7;

S5.7: according to mapping scheme M _mpre-deduction bottom-layer network resource, if bottom-layer network resource residual amount is greater than 0 after deduction, maps successfully, preserves MVN mapping scheme M _m, otherwise MVN request maps unsuccessfully.

3. on-line mixing mapping method of virtual network according to claim 2, is characterized in that, in described step S4.2, and expense Cost (v → n _k) computing formula be:

Cost(v→n _k)＝(p(n _k)+(MC-Con(n _k))*ε(v)+1/R _n(n _k)+1/R _e(AdjLink(n _k))

Wherein, p (n _k) represent bottom layer node n _kthe unit cost of resource, Con (n _k)=| Adj (n _k) | represent bottom layer node n _kadjacent degree, MC is the value that in all bottom layer node, adjacent degree is maximum, and ε (v) represents the node resource requirement of the root node v that MVN asks, R _n(n _k) represent bottom layer node n _ksurplus resources, AdjLink (n _k) represent bottom layer node n _kadjacent link set, R _e(AdjLink (n _k)) represent bottom layer node n _kthe remaining resource capacity sum of adjacent link.

4. mixing virtual map method according to claim 1, is characterized in that, in described step S6, during clean culture virtual network UVN asks, the mapping method of virtual link and dummy node is:

S6.1: initialization N _mapped=N _uV∩ N _mV, namely try to achieve multicast virtual set of network nodes N _mVwith clean culture virtual network node set N _uVthe dummy node set of middle overlap, initialization set UMN _v=N _uV-N _mapped, from clean culture virtual network link set E _uVin choose to gather N _mappedmiddle dummy node is the virtual link of source node, and the set of these virtual links is designated as E, according to the mapping scheme of MVN request, will gather N _mappedin node mapping result be updated to UVN mapping scheme M _u;

S6.2: judge whether if so, enter step S6.5, otherwise enter step S6.3;

S6.3: if enter step S6.4, otherwise enter step S6.5;

S6.4: take out a virtual link e from set E _q, map, if be successfully mapped to bottom path according to link circuit resource requirement and delay requirement upgrade E=E-e _q, return step S6.3, otherwise UVN request maps unsuccessfully;

S6.5: if enter step S6.6, otherwise UVN asks mapping to complete, export UVN mapping scheme M _u;

S6.6: from UMN _vmiddle selection one and N _mappedthe dummy node v that middle dummy node is adjacent _g, by dummy node v _gwith N _mappedvirtual link between middle adjacent node puts into set E; Maps virtual node v _gwith Article 1 link e in set E _h, attempt dummy node v _gbe mapped to UMN ^sin each bottom layer node n _k, find e according to link circuit resource requirement, delay requirement _hpath candidate calculate maps virtual node v _gto bottom layer node n _kexpense Cost (v _g→ n _k), if there is no suitable path candidate then make Cost (v _g→ n _k)=∞;

S6.7: select minimum Cost (v _g→ n _k), if min is (Cost (v _g→ n _k))=∞, UVN request maps unsuccessfully, otherwise enters step S6.8.

S6.8: by min (Cost (v _g→ n _k)) corresponding bottom layer node is as dummy node v _gmapping node, these mapping relations are updated to UVN mapping scheme M _uin, upgrade bottom-layer network resource, make UMN _v=UMN _v-v _p, UMN ^s=UMN ^s-n _k, N _mapped=N _mapped+ v _g, E=E-e _h, return step S6.3.

5., according to the arbitrary described on-line mixing mapping method of virtual network of Claims 1-4, when described virtual link maps, adopt the random multiplex strategy of link bandwidth resource when calculating link circuit resource and taking and deduct with link circuit resource.