CN104144135A - Resource distribution method and survivability resource distribution method used for multicast virtual network - Google Patents

Abstract

The invention discloses a resource distribution method used for a multicast virtual network (MVN) and belongs to the technical field of MVNs. According to the method, firstly, current physical network information is collected, starting from the root node of the MVN, corresponding physical nodes are distributed to all virtual nodes in sequence, and a pair of the virtual node and the physical node is removed from corresponding node sets to be mapped whenever finished through mapping; after mapping configuration is performed on each virtual node, a mapping physical route corresponding to each virtual node is adjusted based on a set time delay window, so that the obtained mapping physical routes meet the service transmission requirement of the MVN, and corresponding working resources are configured. Meanwhile, in order to implement a survivability resource distribution method used for the MVN in single failure regions, on the basis of configuring the mapping resources, the physical nodes and links corresponding to all the failure regions are removed from a physical network, and redundant backup resources are configured for all the failure regions. The resource distribution method and the survivability resource distribution method are used for MVN mapping configuration, are high in efficiency and have survivability.

Description

Resource allocation methods and the anti-resource allocation methods of ruining for multicast virtual network

Technical field

The present invention relates to multicast virtual network (Multicast Virtual Network, MVN) technology, be specifically related to a kind of resource allocation methods for multicast virtual network and the anti-resource allocation methods of ruining.

Background technology

The Internet definition obtain in the world today and the model of exchange message mode on obtained huge success.In the past thirty years, the Internet, by supporting application and a large amount of different network technology of large quantities of dispersions, has confirmed the value of self structure.Yet, being widely used of the Internet also becomes maximum obstruction that it further develops, characteristic due to its multi-provider, in the existing structure of the Internet, add new structure or adjust the common approval that need to obtain all operators, thereby network configuration is now restricted, be merely able to carry out slow simple renewal, and cannot change rapidly.Network virtual is turned to the technological means that solves the rigid problem of current internet, has been subject in recent years the extensive concern of domestic and international future network area research.One of advantage of network virtualization is to support the network architecture of a plurality of isomeries to share physical infrastructure.Its essence of network virtualization technology is on a public physical network, to run independently a plurality of virtual nets by abstract, distribution, isolation mech isolation test, thereby can carry out selectively best resource, distributes and scheduling.

The virtualized object of network is exactly to realize extensively sharing of distributed virtual resource, so virtual resource mapping is the critical function that network virtualization Technology Need is realized.Virtual resource mapping algorithm is as one of key issue of network virtualization technology, it has been realized user's virtual network request has reasonably been mapped to the process 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.

Well-known internetwork communication has the forms such as clean culture, multicast, broadcast, wherein multicast is widely used in the real-time application of the high QoS of many needs, and the virtual network mapping problems in multicast situation can first change into and in lower floor's network, find multicast subnet.Heuritic approach is the common method that solves virtual resource mapping problems, and it is defined function h (n) on network node, for assessment of node from then on to the most cheap path of destination node.In algorithm, comprise node resource distribution and link circuit resource and distribute two parts.Node resource distribution refers to: according to the constraints of dummy node, the resource of bottom layer node is distributed to dummy node.Link circuit resource distributes and to refer to: according to the source node of virtual link and the mapped bottom layer node of destination node and the constraints of virtual link, a bottom link of bottom-layer network or the resource of many bottom links are distributed to virtual link.

For MVN problem, VMNDDVCM (Virtual multicast network with delay and delay variation constraints mapping) algorithm is a kind of mapping method of common solution multicast virtual network, the method has considered the particularity of multicast virtual network, the time delay of multicast network and the characteristic of delay variation have been introduced, by introducing window sliding mechanism, having solved the delay variation in mapping process retrains, adopt enumeration strategy to find the satisfied optimum multicast tree retraining to complete mapping, guaranteed optimum mapping cost.Although said method can be realized multicast virtual network mapping, but when completing mapping, adopted the mechanism of enumerating, although guaranteed the optimum of mapping result, algorithm complex is higher, convergence rate is too slow, especially can not be applicable to fairly large virtual network mapping problems; And, the method also reckons without the situation that the burst of bottom-layer network was lost efficacy, can not make corresponding processing to the inefficacy of node in bottom-layer network and link, that cannot realize multicast virtual network anti-ly ruins mapping, cannot solve the survivability problem of multicast virtual network mapping.

In the research about mapping method of virtual network, CPP (Cluster Protecting Provision) and VNP (Virtual Network Protecting) algorithm are the methods of the virtual network mapping of more common consideration survivability, can allow the inefficacy of mapping server and a bottom data central site network link of a dummy node simultaneously, and from lose efficacy, recover timely.The method is by the mode of 1:1, node and link to be protected, take minimize mapping cost be target, virtual network is mapped on bottom-layer network.After mapping completes, the virtual network of identical Resources Consumption in the work of having shone upon of take provides protection.Although said method can be realized virtual network anti-ly ruins mapping, it only proposes for clean culture virtual network mapping problems.In actual applications, there is a large amount of multicast virtual network mapping demands, and the existing anti-method of ruining mapping that can realize virtual network is because taking into account the various particularity constraints of multicast virtual network mapping, particularity constraint mainly refers to time delay and delay variation, be that the network resource requirement of each dummy node is (such as network capacity, time delay expense, delay variation is delay inequality etc. in other words), thereby can not be applicable to multicast virtual network mapping problem; In addition; anti-ruining in virtual network mapping scheme under redundancy backup resource allocation mechanism (being that every part of working resource is corresponding to the reserved resource of a equivalent) mode of 1:1; because it does not introduce Resources Sharing, this can consume higher resources costs by causing in virtual network mapping process.

Summary of the invention

Goal of the invention of the present invention is: for the problem of above-mentioned existence, provide a kind of efficient and can be applicable to the Optimal Configuration Method of the bottom-layer network resource of extensive multicast virtual network mapping.

Resource allocation methods for multicast virtual network of the present invention, comprises the following steps:

Step 1: obtain initialization information:

Obtain the network resource information of current physical network, initialization is mapping physical node set UMN not ^sall physical node n for current physical network _k; Do not shine upon dummy node set UMN _vrelated all dummy node v for current multicast virtual network MVN request _i;

Step 2: the network topology structure based on current MVN request, builds about each dummy node v _itwo layers of spanning tree, and distribute corresponding physical node for the fake root node v of described two layers of spanning tree:

According to formula Cost (v → n _k)=(p'(n _k)+(MC-Con (n _k))) * ε (v) calculates respectively described fake root node v and be mapped to each physical node n _kresource overhead estimated value Cost (v → n _k), p'(n wherein _k)=p (n _k)+α * AF (n _k) be physical node n _kthe virtual unit cost of node resource, described p (n _k) expression physical node n _kthe unit cost of node resource, AF (n _k) represent to affect physical node n _kthe quantity of failed areas, adjustable factors α is any real number; Described MC is the value of node degree maximum in the network topology knot figure of current physical network, Con (n _k)=| Adj (n _k) | represent physical node n _knode degree, ε (v) represents the resource requirement capacity of fake root node v;

Get least resource expense estimated value Cost (v → n _k) corresponding physical node n _kfor the mapping node of fake root node v, and be designated as n _s;

Step 3: by fake root node v and physics n _smapping relations v → n _sstore in resource allocation table M; And mapping physical node set UMN never ^smiddle deletion of physically node n _s, never shine upon dummy node set UMN _vmiddle deletion dummy node v;

Step 4: to not shining upon dummy node set UMN _vupgrade processing:

According to formula calculate respectively each dummy node v _iweights DR (v _i), ε (v wherein _i) expression dummy node v _iresource requirement capacity, represent fake root node v and dummy node v _iconnected virtual link e _ibandwidth resources requirements, adjustable factors λ is any real number;

Based on each dummy node v _iweights DR (v _i), the not mapping dummy node set UMN after being upgraded by descending sort _v;

Step 5: based on current not mapping physical node set UMN ^s, to the current dummy node set UMN that do not shine upon _vin each dummy node v _i, from left to right carry out successively resource distribution:

Step 501: to dummy node v _i, based on current not mapping physical node set UMN ^s, find out and meet dummy node v _inetwork resource requirement from physical node n _sto candidate physical node n _kshortest path, described candidate physical node n _kbelong to current set UMN ^s, and according to formula Cost (v _i→ n _k)=CNn _k+ CPn _kcalculate each physical node n _kas dummy node v _icandidate mappings node time resource overhead estimated value Cost (v _i→ n _k);

Record resource overhead estimated value Cost (v _i→ n _k), and physical node n _sto physical node n _kshortest path be virtual link e _imapping physical path if do not exist from physical node n _sto candidate physical node n _kshortest path, make corresponding resource overhead estimated value Cost (v _i→ n _k) be default maximum;

CNn wherein _k=p'(n _k) * ε (v _i) be dummy node v _ibe mapped to physical node n _kon the virtual expense of resource;

Described for virtual link e _imapping physical path the virtual expense of resource, p'(e wherein)=p (e)+α * AF (e), described p (e) represents the unit cost of the link circuit resource of physical link e, and AF (e) expression affects the quantity of the failed areas of physical link e, and described link e belongs to mapping physical path

Step 502: get least resource expense estimated value Cost (v _i→ n _k) corresponding physical node n _kfor current virtual joint v _imapping node, and by mapping relations v _i→ n _k, mapping physical path store in resource allocation table M; While is mapping physical node set UMN never ^sthe current physical node n of middle deletion _k, do not shine upon dummy node set UMN _vthe current dummy node v of middle deletion _i;

Step 503: repeated execution of steps 501,502, until mapping dummy node set UMN _vfor sky;

Step 6: time delay window W=[D is set according to current MVN request _max-C _dV, D _max], the mapping physical path in adjustresources allocation table M: whether the time delay that judges each mapping physical path in resource allocation table M in described time delay window W, if not, adjusts current mapping physical path upgrade resource allocation table M: based on the corresponding mapping relations v in current mapping physical path _i→ n _k, in physical network topology figure, find out from physics n _sto physical node n _kfront K bar shortest path, and from described K bar shortest path, select the shortest path of time delay in described time delay window W to replace current mapping physical path wherein said D _maxrepresent in all mapping physicals path in resource allocation table M the maximum path delay of time; C _dVthe poor binding occurrence of link maximum delay that represents current MVN request.

Based on resource allocation methods of the present invention, the invention allows for a kind of anti-resource allocation methods of ruining for the multicast virtual network under single failed areas, to solve the survivability problem of multicast virtual network mapping, take given all possible failed areas as basis, and in the situation that allowing bottom-layer network to occur an area failures at most simultaneously, realize multicast virtual network mapping, and introduce certain fault tolerant mechanism, make, after multicast virtual network mapping success, can in the situation that any one area failures appears in bottom physical network, normally work.

Under single failed areas of the present invention, the anti-resource allocation methods of ruining of multicast virtual network, comprises the following steps:

Step S1: be that current MVN asks to share out the work resource allocation table M based on resource allocation methods claimed in claim 1;

Step S2: for current MVN request distributes standby resources allocation table:

Step S201: determine each failed areas r in current physical network _i, by each failed areas r _iform failed areas set R;

Step S202: be respectively each failed areas r _idistribute standby resources allocation table M _i: by failed areas r _irelated physical node and link are rejected from the network topology of current physical network; The corresponding network resource information of physical network topology based on after reject processing again, MVN request distributes corresponding failed areas r described in resource allocation methods according to claim 1 _istandby resources allocation table M _i;

Step S3: store described working resource allocation table M and each failed areas r _istandby resources allocation table M _i, and be sent to each physical node.

In sum, owing to having adopted technique scheme, the invention has the beneficial effects as follows: the present invention can efficiently realize the most optimum distribution of resources of extensive multicast virtual network mapping, for the mapping of multicast virtual net, reserved resource backup simultaneously, made multicast virtual network in the situation that an any given area failures can continue normal work.

Accompanying drawing explanation

MUV mapping example when Fig. 1 is single area failures, wherein node a, b, the c in figure (a) represents that MVN asks related dummy node, numeral in the rectangle frame of corresponding each dummy node (numeral " 4 ", " 5 ") represents the requirement of each dummy node resource in MVN request, and 3 numerals between two dummy nodes on line represent respectively the demand information to link circuit resource, time delay and delay variation; Node A, B, C, D, E, the F of figure (b) represent physical node, numeral in corresponding each physical node in rectangle frame (numeral " 20|3 ", " the 20|4 ") left side is the available resources total amount of physical node, the right is the cost of unit node resource, numeral on each physical link (numeral " 30|5|3 ", " 30|3|1 ", " 30|4|2 " etc.) left side is the available physical link circuit resource total amount of physical link, sandwich digit is the cost of unit physical link resource, and the right numeral is physical link time delay;

Fig. 2 is that minimal-overhead set covers schematic diagram.

Embodiment

For making the object, technical solutions and advantages of the present invention clearer, below in conjunction with execution mode and accompanying drawing, the present invention is described in further detail.

For the ease of realization of the present invention, in the present invention, the request of MVN is configured to undirected weighted graph G _v=(N _v, E _v, C _n, C _l, C _d, C _dV) model, specifically, service-oriented MVN request can be expressed as a two-layer tree, as (a) figure in Fig. 1, wherein, N _v={ v ₁, v ₂..., v _i... v _trepresent the dummy node set of MVN, total number that T is dummy node, E _v={ e ₁, e ₂...., e _i..., e _trepresent the virtual link set of MVN, e _irepresent to connect fake root node v to leaf node v _ivirtual link, C _nthe node resource constraint information that represents a dummy node, represent each virtual link bandwidth constraint information, C _dVrepresent the poor constraint information of virtual link maximum delay, G _vrelated above-mentioned information all can the acquisition request based on MVN arrive.

Similarly, in the present invention, physical network (bottom-layer network) is configured to undirected weighted graph G ^s=(N ^s, E ^s, C ⁿ, C ^l) model, wherein N ^sthe set of all physical nodes of physical network (for example Fig. 1 midway node A, B, C, D, E, the F shown in (b)), E ^sthe set of all physical links of physical network, for each physical node n _k∈ N ^scan be for MVN node provides resource, C ⁿrepresent physical node Resource Properties, as the resource capacity of node, C ^lrepresent each physical link attribute, comprise the information such as bandwidth and time delay;

Similarly, definition MVN virtual link set E _vthe mapping set in layer physical network path is on earth represent corresponding virtual link e _imapping physical path in physical network, so each mapping physical path e ^ssubset.So mapping physical path end to end time delay and available bandwidth resources can be expressed as with with can calculate according to formula below:

$D\left(p_{e_i}\right)=\underset{e\∈p_{e_i}}{\mathrm{\Σ}}d\left(e\right),\∀p_{e_i}\∈P$

$B\left(p_{e_i}\right)=\underset{e\∈p_{e_i}}{\min }\left\{b\left(e\right)\right\},\∀p_{e_i}\∈P$

Wherein d (e) represents the time delay of physical link e, and b (e) represents the available bandwidth resources of physical link e.

With the above-mentioned basis that is defined as, by dummy node set and dummy node resource requirement set (N _v, C _n) be mapped to the set of bottom physical network nodes and node resource set (N ^s, C ⁿ) on can be expressed as: to any dummy node make M _n(v _i)=n _k.

By dummy node v _ibe mapped in physical node n _kupper, mean at physical node n _kdistributed to dummy node v _iresource requirement capacity ε (v _i), so n _kon available resources capacity R _n(M _n(v _i)) must be not less than ε (v _i), constraint is as follows:

$R_n\left(M_N\left(v_i\right)\right)\≥\mathrm{\ϵ}\left(v_i\right),\∀v_i\∈N_V---\left(1\right)$

The same, virtual link set and physical link resource requirement set (E _v, C _l) be mapped in bottom-layer network link set and link circuit resource set and can be expressed as: $M_E:(E_V,C_L)\stackrel{M}{\→}(P,C^L),$ To arbitrarily make $M_E\left(e_i\right)=p_{e_i},$ Virtual link e _ibe mapped in bottom physical network path upper, mean bottom physical network path distributed to virtual link e _irequired link bandwidth resource so bottom physical network path available bandwidth resources B (M _e(e _i)) must be not less than constraint is as follows:

$B\left(M_E\left(e_i\right)\right)\≥x_{e_i},\∀e_i\∈E_V---\left(2\right)$

Simultaneously total time delay and delay variation also must meet constraints below:

$D\left(M_E\left(e_i\right)\right)\≤C_D,\∀e_i\∈E_V---\left(3\right)$

$\begin{array}{cccc}|D\left(M_E\left(e_i\right)\right)-D\left(M_E\left(e_j\right)\right)|\≤C_{\mathrm{DV}},& \∀e_i,e_j\∈E_V& \mathrm{and}& e_i\≠e_j---\left(4\right)\end{array}$

Constraint formula (3) is guaranteed: mapping physical path time delay D (M _e(e _i)) be no more than the delay upper bound C of MVN request _d.Constraint formula (4) is guaranteed: the delay inequality between any two mapping physical paths is no more than the delay inequality upper limit C of MVN request _dV.

The inherent constraint condition that above-mentioned 4 constraintss are multicast virtual network mapping, be the related corresponding network resource requirement information of each dummy node in MVN request, the present invention is under the prerequisite that meets above-mentioned 4 each constraintss, realized the resource distribution that each dummy node is mapped to different physical nodes, concrete execution step is as follows:

Step 1:

Initialization process

The network resource information that obtains current physical network, obtains G ^s=(N ^s, E ^s, C ⁿ, C ^l);

Acquisition request G based on current MVN _v=(N _v, E _v, C _n, C _l, C _d, C _dV);

Initialization is mapping physical node set UMN not ^s=N ^s, do not shine upon dummy node set UMN _v=N _v, resource allocation table

Step 2:

Network topology structure based on current MVN request, the network topology structure based on current MVN request, builds about each dummy node v _itwo layers of spanning tree, and distribute corresponding physical node for the fake root node v of described two layers of spanning tree:

To each n _k∈ UMN ^s, according to formula (5), calculate to calculate and record fake root node v respectively and be mapped to each physical node n _kresource overhead estimated value Cost (v → n _k);

Get least resource expense estimated value Cost (v → n _k) corresponding physical node n _kfor the mapping node of fake root node v, and be designated as n _sif there are a plurality of minimum Cost (v → n _k), select arbitrarily one of them as mapping node.

Formula (5) is: Cost (v → n _k)=(p'(n _k)+(MC-Con (n _k))) * ε (v),

Wherein, p'(n _k)=p (n _k)+α * AF (n _k) be physical node n _kthe virtual unit cost of node resource, p (n _k) expression physical node n _kthe unit cost of node resource, AF (n _k) represent to affect physical node n _kthe quantity of failed areas, adjustable factors α is any real number, α plays guiding mapping here and avoids failed areas; MC is the value of node degree maximum in the network topology knot figure of current physical network, Con (n _k)=| Adj (n _k) | represent physical node n _knode degree (be that MC is all Con (n _k) in the corresponding value of maximal term), ε (v) represents the resource requirement capacity of fake root node.The virtual cost of unit is lower like this, spends the mapping node that larger physical node more easily becomes fake root node.The physical node that configuration degree is larger becomes mapping node corresponding to MVN fake root node, and other leaf node just has more selection to the link maps of fake root node v.

Step 3:

Upgrade resource allocation table M: by the fake root node v of virtual network and physics n _smapping relations v → n _sstore in resource allocation table M;

Upgrade set UMN ^sand UMN _v: make UMN ^s=UMN ^s-n _s, UMN _v=UMN _v-v;

UMN after this renewal _vbe the set of all-multicast virtual network leaf node, the object of renewal is to allow different dummy nodes be mapped to different physical nodes;

Step 4:

To not shining upon dummy node set UMN _vin each element again enter sequence and process:

According to formula (6) set of computations UMN _vin the weighted value of each dummy node, and by descending sort, pair set UMN _vin the rearrangement of each element after, before just the large dummy node of resource requirement having been come, so the large node of resource requirement just can preferentially obtain shining upon configuration process, thereby can reduce blocking rate, successful possibility is shone upon in raising.

Formula (6) is: its physical significance is the link bandwidth resource λ addition in proportion that the required node resource of dummy node is connected with this node with fake root node, wherein adjustable factors λ is any real number, so just node resource demand and link circuit resource need integrate is considered.

Step 5: based on current not mapping physical node set UMN ^s, to the current dummy node set UMN that do not shine upon _vin each dummy node v _i, from left to right carry out successively resource distribution:

Step 501: to each dummy node v _i∈ UMN _v, meeting under the prerequisite of constraints (1), (2), (3), at directed graph G ^sin find out physical node n _sto candidate physical node n _kshortest path, n wherein _k∈ UMN ^s; If there is the physical node n that meets constraints (1), (2), (3) _sto physical node n _kshortest path, according to formula (7), calculate dummy node v _ibe mapped to candidate physical node n _kresource overhead estimated value Cost (v _i→ n _k); If do not exist, make resource overhead value Cost (v _i→ n _k) for default maximum, for example, configure Cost (v _i→ n _k)=∞;

Record current dummy node v _iwith each physical node n _kresource overhead value Cost (v _i→ n _k), and corresponding mapping physical path this mapping physical path be from physical node n _sto physical node n _kshortest path;

Formula (7) is Cost (v _i→ n _k)=CNn _k+ CPn _k, CNn wherein _k=p'(n _k) * ε (v _i) be dummy node v _ibe mapped to physical node n _kon the virtual expense of resource; for virtual link e _ithe virtual expense of mapping physical path resource, p'(e wherein)=p (e)+α * AF (e), p (e) represents the unit cost of the link circuit resource of physical link e, AF (e) represents to affect the quantity of the failed areas of physical link e;

Step 502: each resource overhead estimated value Cost (v calculating based on step 501 _i→ n _k), get the corresponding physical node n of minterm _kfor current virtual joint v _imapping node, and by mapping relations v _i→ n _k, mapping physical path store in resource allocation table M; If there are a plurality of minterms simultaneously, selecting arbitrarily the corresponding physical node of one of them minterm is current virtual joint v _imapping node;

Simultaneously from set UMN ^sand UMN ^srejecting is to complete two nodes of mapping, even UMN ^s=UMN ^s-n _k, UMN _v=UMN _v-v _i;

Step 503: repeated execution of steps 501,502, until mapping dummy node set UMN _vfor sky.

Step 6: based on constraint formulations (4), correspondence mappings physical pathway in resource allocation table M is adjusted, in the time can not meeting the mapping physical path of constraints (4) between the path that is present in minimal time delay, need again to look for a feasible replacement path, in order significantly to reduce in constraints (4) comparing between two brought computation complexity between path, the present invention is according to time delay window W=[D _max-C _dV, D _max] judge all mapping physicals path in resource allocation table M whether there is the mapping physical path that does not meet time delay window W, if exist, again search feasible replacement path, be specifically treated to:

Whether the time delay that judges each mapping physical path in resource allocation table M in described time delay window W, if not, adjusts current mapping physical path upgrade resource allocation table M: based on the corresponding mapping relations v in current mapping physical path _i→ n _k, in physical network topology figure, find out from physics n _sto physical node n _kfront K (preset value, based on practical application scene, carry out value) bar shortest path, for example can obtain K bar shortest path by conventional K-shortestpaths (front K bar shortest path) algorithm, and from this K bar shortest path, select the shortest path of time delay in described time delay window W to replace current mapping physical path

D wherein _maxrepresent in all mapping physicals path in resource allocation table M the maximum path delay of time; C _dVthe poor binding occurrence of link maximum delay that represents current MVN request.

In order to realize the redundancy backup to the physical network resource configuration of multicast virtual network under single failed areas, when any single area failures, multicast virtual net can be restored, thereby guarantees the survivability of multicast virtual net;

First the application scenarios based on physical network, determine the failed areas r may losing efficacy _i, each failed areas r of being known by system _iform failed areas set R.So-called failed areas refers to the reasons such as power failure, earthquake, and the regional faults of the bottom physical network causing may occur a plurality of physical node equipment and multilink equipment failure conventionally simultaneously.For each failed areas r _i∈ R can destroy one or more physical nodes and all physical links that are connected with these physical nodes simultaneously, and for convenience of description, the present invention is by corresponding failed areas r _ifailed areas be described as wherein with two failed areas as exemplified in Fig. 1 (b), as can be seen from the figure wherein with $E_{r_1}=\{A-F,$ $B-F,E-F,A-E,D-E\};G\left(r_2\right)=(N_{r_2},E_{r_2}),$ Wherein $N_{r_2}=\{C,D\}$ With $E_{r_2}=\{A-C,B-C,A-D,C-D,$ $D-E\}.$

Secondly, be that current MVN request distributes standby resources allocation table, when the dummy node of multicast virtual network or link maps are to failed areas r _iwhen interior, in order to guarantee the survivability of multicast virtual network, just must never comprise r _ithe reserved resource in region, as region r _iwhile occurring to lose efficacy, the request of multicast virtual net can recover from reserved resource, thereby guarantees the survivability of multicast virtual net, namely for the reserved resource backup of multicast virtual net mapping guarantees survivability:

To each r _i∈ R, by failed areas r _irelated physical node and link are rejected from the network topology of current physical network, upgrade G ^s=G ^s-G (r _i); G based on after upgrading ^s, MVN request distributes corresponding failed areas r described in resource allocation methods according to claim 1 _istandby resources allocation table M _i;

Finally, storage working resource allocation table M and each failed areas r _istandby resources allocation table M _i, and be sent to each physical node.

Although the resource allocation table M that above-mentioned steps obtains and each standby resources allocation table M _i, can guarantee the normal work of multicast virtual net in single area failures situation, but have how many failed areas just to have how many standby resources allocation table M _i, and for some standby resources allocation table M _i, may have a plurality of failed areas can from mapping M _iin recover, so just there is a large amount of redundancies in resource allocation table M, in order to eliminate redundancy, resource is utilized more fully, to resource allocation table, M is optimized processing, is specially:

Step (1): based on the current standby resources allocation table M obtaining _i, calculate respectively each standby resources allocation table M _iminimum mapping cost and c (M about all dummy nodes and link _i);

Step (2) is according to formula min{c (M _i)/| U (M _i) | select corresponding M _i, and by the corresponding standby resources table of current minterm M _istore in minimum standby resources allocation table M*, and upgrade working resource allocation table M=M-M _i, upgrade failed areas set R: in failed areas set R, deleting can be from standby resources allocation table M simultaneously _ithe failed areas of middle recovery;

Step (3): each failed areas r that the failed areas set R after upgrading based on step (4) comprises _icorresponding minimum mapping cost and c (M _i), continue execution step (2), until failed areas set R is empty;

Finally, store the current resource allocation table M that shares out the work (eliminating after redundancy) and minimum standby resources allocation table M*, and be sent to each physical node.

Above-mentioned formula min{c (M _i)/| U (M _i) | in, | U (M _i) | expression can be from standby resources allocation table M _ithe failed areas number of middle recovery, can be from mapping M _iin the number of the failed areas that recovers may more than one, as shown in Figure 2, can be from standby resources allocation table M ₂in the failed areas that recovers comprise r ₁and r ₂two.Obviously | U (M _i) | be worth larger, M _ijust more likely be added into M ^*in, and M ^*also may be less.In like manner exist | U (M _i) | in fixing situation, c (M _i) less, M _ijust more likely be added into M ^*in.

Embodiment 1

The anti-resource allocation methods of ruining of multicast virtual network under a kind of single failed areas of the present invention is deployed in SDN network, to realize the mapping of multicast virtual Network.

First by SDN control router scheduling self with control and management function gather bottom physical network topology and corresponding resource information, comprise all physics node resource situations in bottom physical network, and physical link resource, the resource informations such as time delay;

When receiving MVN request, SDN controls physical network topology and the corresponding resource information of router based on current gathered, the anti-resource allocation methods of ruining based on multicast virtual network under a kind of single failed areas of the present invention, calculate corresponding dummy node and the map information of physical node, the task of the dummy node of respective virtual multicast service is distributed to the physical node of mapping, and send corresponding Work route and route stand-by information (being working resource allocation table M and minimum standby resources allocation table M*), complete the actual mapping of multicast virtual network.

To sum up, the beneficial effect that the present invention brings is embodied in:

(1) optimization.Solved CPP, VNP algorithm insurmountable multicast virtual network mapping problem and various restricted problem have been introduced minimal set cover algorithm optimization mapping result simultaneously, eliminate redundant resource, have reduced the mapping cost of multicast virtual network;

(2) compatibility.Not only can solve as VMNDDVCM algorithm for the mapping of multicast virtual network, but also solved the survivability problem of the multicast virtual network mapping in single area failures situation, make multicast virtual network in the situation that an any given area failures is normally worked;

(3) predictability.Calculating least resource expense estimated value Cost (v → n _k) time, used virtual unit cost and Guiding factor α, failed areas is avoided in guiding mapping to a certain extent, thereby reaches the effect of inefficacy perception, reduces the adverse effect of failed areas.

The above, be only the specific embodiment of the present invention, and arbitrary feature disclosed in this specification, unless narration especially all can be replaced by other equivalences or the alternative features with similar object; Step in disclosed all features or all methods or process, except mutually exclusive feature and/or step, all can be combined in any way.

Claims (3)

1. for a resource allocation methods for multicast virtual network, it is characterized in that, comprise the following steps:

Step 1: obtain initialization information:

Obtain the network resource information of current physical network, initialization is mapping physical node set UMN not ^sall physical node n for current physical network _k; Do not shine upon dummy node set UMN _vrelated all dummy node v for current multicast virtual network MVN request _i;

Step 2: the network topology structure based on current MVN request, builds about each dummy node v _itwo layers of spanning tree, and distribute corresponding physical node for the fake root node v of described two layers of spanning tree:

According to formula Cost (v → n _k)=(p'(n _k)+(MC-Con (n _k))) * ε (v) calculates respectively described fake root node v and be mapped to each physical node n _kresource overhead estimated value Cost (v → n _k), p'(n wherein _k)=p (n _k)+α * AF (n _k) be physical node n _kthe virtual unit cost of node resource, described p (n _k) expression physical node n _kthe unit cost of node resource, AF (n _k) represent to affect physical node n _kthe quantity of failed areas, adjustable factors α is any real number; Described MC is the value of node degree maximum in the network topology knot figure of current physical network, Con (n _k)=| Adj (n _k) | represent physical node n _knode degree, ε (v) represents the resource requirement capacity of fake root node v;

Get least resource expense estimated value Cost (v → n _k) corresponding physical node n _kfor the mapping node of fake root node v, and be designated as n _s;

Step 3: by fake root node v and physics n _smapping relations v → n _sstore in resource allocation table M; And mapping physical node set UMN never ^smiddle deletion of physically node n _s, never shine upon dummy node set UMN _vmiddle deletion dummy node v;

Step 4: to not shining upon dummy node set UMN _vupgrade processing:

According to formula calculate respectively each dummy node v _iweights DR (v _i), ε (v wherein _i) expression dummy node v _iresource requirement capacity, represent fake root node v and dummy node v _iconnected virtual link e _ibandwidth resources requirements, adjustable factors λ is any real number;

Based on each dummy node v _iweights DR (v _i), the not mapping dummy node set UMN after being upgraded by descending sort _v;

Step 5: based on current not mapping physical node set UMN ^s, to the current dummy node set UMN that do not shine upon _vin each dummy node v _i, from left to right carry out successively resource distribution:

Step 501: to dummy node v _i, based on current not mapping physical node set UMN ^s, find out and meet dummy node v _inetwork resource requirement from physical node n _sto candidate physical node n _kshortest path, described candidate physical node n _kbelong to current set UMN ^s, and according to formula Cost (v _i→ n _k)=CNn _k+ CPn _kcalculate each physical node n _kas dummy node v _icandidate mappings node time resource overhead estimated value Cost (v _i→ n _k);

Record resource overhead estimated value Cost (v _i→ n _k), and physical node n _sto physical node n _kshortest path be virtual link e _imapping physical path if do not exist from physical node n _sto candidate physical node n _kshortest path, make corresponding resource overhead estimated value Cost (v _i→ n _k) be default maximum;

CNn wherein _k=p'(n _k) * ε (v _i) be dummy node v _ibe mapped to physical node n _kon the virtual expense of resource;

Described for virtual link e _ithe virtual expense of mapping physical path resource, p'(e wherein)=p (e)+α * AF (e), described p (e) represents the unit cost of the link circuit resource of physical link e, AF (e) expression affects the quantity of the failed areas of physical link e, and described link e belongs to mapping physical path

Step 502: get least resource expense estimated value Cost (v _i→ n _k) corresponding physical node n _kfor current virtual joint v _imapping node, and by mapping relations v _i→ n _k, mapping physical path store in resource allocation table M; While is mapping physical node set UMN never ^sthe current physical node n of middle deletion _k, do not shine upon dummy node set UMN _vthe current dummy node v of middle deletion _i;

Step 503: repeated execution of steps 501,502, until mapping dummy node set UMN _vfor sky;

Step 6: time delay window W=[D is set according to current MVN request _max-C _dV, D _max], the mapping physical path in adjustresources allocation table M: whether the time delay that judges each mapping physical path in resource allocation table M in described time delay window W, if not, adjusts current mapping physical path upgrade resource allocation table M: based on the corresponding mapping relations v in current mapping physical path _i→ n _k, in physical network topology figure, find out from physics n _sto physical node n _kfront K bar shortest path, and from described K bar shortest path, select the shortest path of time delay in described time delay window W to replace current mapping physical path wherein said D _maxrepresent in all mapping physicals path in resource allocation table M the maximum path delay of time; C _dVthe poor binding occurrence of link maximum delay that represents current MVN request.

2. the anti-resource allocation methods of ruining of multicast virtual network under single failed areas, is characterized in that, comprises the following steps:

Step S1: be that current MVN asks to share out the work resource allocation table M based on resource allocation methods claimed in claim 1;

Step S2: for current MVN request distributes standby resources allocation table:

Step S201: determine each failed areas r in current physical network _i, by each failed areas r _iform failed areas set R;

Step S202: be respectively each failed areas r _idistribute standby resources allocation table M _i: by failed areas r _irelated physical node and link are rejected from the network topology of current physical network; The corresponding network resource information of physical network topology based on after reject processing again, MVN request distributes corresponding failed areas r described in resource allocation methods according to claim 1 _istandby resources allocation table M _i;

Step S3: store described working resource allocation table M and each failed areas r _istandby resources allocation table M _i, and be sent to each physical node.

3. method as claimed in claim 2, is characterized in that, in described step S2, also comprises:

Step S203: calculate respectively each standby resources allocation table M _iminimum mapping cost and c (M about all dummy nodes and link _i);

Step S204: according to formula min{c (M _i)/| U (M _i) | selection M _i, by described M _istore in minimum standby resources allocation table M*, and upgrade working resource allocation table M=M-M _i, upgrade failed areas set R: in failed areas set R, deleting can be from standby resources allocation table M simultaneously _ithe failed areas of middle recovery;

Wherein said | U (M _i) | expression can be from standby resources allocation table M _ithe failed areas number of middle recovery;

Step S205: each failed areas r that the failed areas set R after upgrading based on step S204 comprises _icorresponding minimum mapping cost and c (M _i), continue execution step 204, until failed areas set R is empty;

Step S3: store current resource allocation table M and the minimum standby resources allocation table M of sharing out the work ^*, and be sent to each physical node.