[go: up one dir, main page]

CN100369432C - A Spanning Tree Topology Abstraction Method Applied to Asymmetric Networks - Google Patents

A Spanning Tree Topology Abstraction Method Applied to Asymmetric Networks Download PDF

Info

Publication number
CN100369432C
CN100369432C CNB2005101241063A CN200510124106A CN100369432C CN 100369432 C CN100369432 C CN 100369432C CN B2005101241063 A CNB2005101241063 A CN B2005101241063A CN 200510124106 A CN200510124106 A CN 200510124106A CN 100369432 C CN100369432 C CN 100369432C
Authority
CN
China
Prior art keywords
topology
abstract
weight
node
spanning tree
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
CNB2005101241063A
Other languages
Chinese (zh)
Other versions
CN1787470A (en
Inventor
纪越峰
雷蕾
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Beijing University of Posts and Telecommunications
Original Assignee
Beijing University of Posts and Telecommunications
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Beijing University of Posts and Telecommunications filed Critical Beijing University of Posts and Telecommunications
Priority to CNB2005101241063A priority Critical patent/CN100369432C/en
Publication of CN1787470A publication Critical patent/CN1787470A/en
Application granted granted Critical
Publication of CN100369432C publication Critical patent/CN100369432C/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Data Exchanges In Wide-Area Networks (AREA)

Abstract

The present invention discloses a method which is applied to spanning tree topology abstract in an asymmetrical network, which carries out a triangular matrix method (TM) of the topology abstract for state parameters of an asymmetrical link. The method has the steps: by an original topology, a complete connected graph abstract topology M of one boundary node is established; undirected complete connected graph abstract topologies (Mu and Ml) are established based on the complete connected graph abstract topology M; minimum spanning tree topologies of Mu and Ml are calculated, which are respectively expressed as Tu and Tl; a directed tree abstract topology T<1>u is established based on the Tu, and each undirected logical link on the Tu is replaced as a pair of directed logical links; three tree abstract topologies (T<1>u, Tu and Tl) are obtained, and the three tree abstract topologies are published to other route domain nodes of the network. All of the asymmetrical information is contained in the tree abstract topologies, and the distortion can be effectively reduced after topology abstract.

Description

Spanning tree topology abstract method applied to asymmetric network
Technical Field
The present invention relates to a topology abstraction method applied in an asymmetric network, and more particularly, to a topology abstraction method applied in an asymmetric automatically switched optical network in the communication field.
Background
In order to realize the expandability and the safety of the network, a layered multi-domain network structure is adopted in both an IP network, an ATM network and an Automatic Switched Optical Network (ASON) which appears in recent years. In a hierarchical network, topology information for each routing domain is first abstracted by a particular topology abstraction algorithm to be published to other routing domains in the network. In this way, each routing domain only maintains the detailed topology information of itself and the abstract topology information of other domains, thereby greatly reducing the amount of information required to be stored and distributed in the network. However, since the abstract topology information is often not accurate enough, the "feasible" route selected according to the information cannot actually meet the Quality of Service (QoS) requirement of the traffic. A well-behaved topology abstraction algorithm attempts to find the best balance point between the two.
The topology abstraction process typically involves two steps. Step 1 is called as 'full connected graph construction', and a full connected graph abstract topology of boundary nodes is formed by constructing a logic link between each pair of boundary nodes. Each logical link is associated with one or more quality of service level parameters according to different quality of service level routing algorithms. The quality of service level parameter may be additive, such as latency; or may be restrictive such as bandwidth. These parameters are derived from the quality of service class parameters of the paths between the border nodes on the original topology. Step 2 is called "full connectivity graph compression", and the full connectivity graph abstract topology is further compressed into a more sparse topology, such as a tree or star topology. The abstracted topology and its corresponding quality of service class parameters are published to other routing domains. If a node in a routing domain receives a tree or star topology of another routing domain, it needs to first decode the topology into a full connectivity graph topology before it can route on the topology.
In recent years, most of the research on the topology abstraction problem takes a symmetric network as a research object. However, asymmetric networks are closer to the actual network model and the topology abstraction problem of asymmetric networks is much more complex than that of symmetric networks. There is a document that replaces two reverse links between each pair of edge nodes in an asymmetric network with a non-directional link, converts the asymmetric network into a symmetric network, and applies a topology abstraction method for the symmetric network thereto. This method, although simple, completely loses the asymmetric information in the original network.
An abstract model: a domain is represented by a three-dimensional vector (V, B, E), where V is a set of nodes within the domain, B  V is a set of nodes at the boundary of the domain, and E is a set of bidirectional links connecting nodes in V. Full connectivity graph for this domain abstracts the topology with (B, L) m ) Is represented by the formula, wherein L m For the logical links between each pair of border nodes. There is a corresponding weight for each logical link. This weight is equal to the weight of the shortest path between logical link boundary nodes in the original topology.
In the case of using the minimum spanning tree abstraction method, the cells with O (| B $) 2 ) The full connectivity graph abstract topology of the logical links will be further abstractly compressed into a minimal spanning tree abstract topology with O (| B |) logical links. With (B, L) t ) Representing the compressed topology, where L t Is a set of logical links. Due to L t L m With L m-t Represents L m -L t The set of logical links in (1). Wherein the set L m The cardinality of (a) is | B | (| B | -1)/2, L t Radix of | B | -1,L m-t Has a cardinal number of 1/2|B 2 -3/2|B | +1. When the spanning tree topology is decoded at the receiving end to be a fully connected graph topology, the logical link (u, v) belongs to L t The weight value of can be directly expanded from the spanning treeDerived from the mapping table, and the logical link (u, v) belongs to L m-t The weight of the user cannot be directly obtained. The following theorem can be derived:
theorem 1: for any logical link (u, v) ∈ L m-t The weight w (u, v) of the link satisfies the following inequality:
Figure C20051012410600071
wherein P is uv Is the only path on the minimum spanning tree for an end node of a logical link (u, v).
The lower bound of w (u, v) can be derived from the properties of the minimum spanning tree, while the upper bound of w (u, v) is derived from the fact that the weight of the logical link in the fully-connected graph abstract topology is equal to the shortest path weight in the original topology. Therefore, each edge in the abstract topology also called a full connected graph satisfies the rule of triangle inequality, that is, in the abstract topology of the full connected graph, there is a triangle-like graph composed of three undirected links, where the sum of the weights of any two undirected links is greater than the weight of the third undirected link.
Another document proposes that when the minimum spanning tree topology is decoded as a fully-connected graph abstract topology, the logical links (u, v) E L can be derived from the theorem m-t The upper or lower bound of the weight is used as the estimated weight of these logical links. However, this method introduces a large weight distortion.
Some documents propose a single-point approximation algorithm (SP) which can reduce distortion to a large extent. By w lb (u, v) represents the lower bound of the link (u, v) weight, w ub (u, v) represents the upper limit, w * (u, v) represents the decoded estimate, then the SP algorithm steps are:
(1) Calculating a floating point value dp according to equation (2) *
Figure C20051012410600072
(2) This floating point value is published to other domains along with the abstract topology, and when the spanning tree topology is decoded to the fully connected graph topology, the estimated weight of the link is calculated using equation (3).
w * (u,v)=w lb (u,v)+dp * ×(w ub (u,v)-w lb (u,v))(3)
Let w (v, u) and w (u, v) be the weights of two links (v, u) and (u, v) in opposite directions between a pair of nodes. Then ρ uv = w (u, v)/w (v, u) asymmetry factor for node pairs u and v. ρ = max (u,v)∈Euv ) Is an asymmetric constant for domain G (V, B, E). Document [1]]The AS method uses a non-directional link between each pair of edge nodes to replace the original two reverse links, and the weight of the non-directional linkHowever, this method has two problems. First, the asymmetry information of the link is completely lost. Secondly, because the weight in the full-connected graph abstract topology is obtained by calculating the shortest path weight from the original topology, each edge of the full-connected graph abstract topology meets the triangle inequality. The minimum spanning tree topology obtained from the fully connected graph topology can obtain the upper limit of the link weight according to the property. However, some links of the symmetric graph obtained by the AS algorithm may lose the triangle inequality property, so that the SP algorithm cannot be applied because the upper limit of the weight cannot be obtained.
Disclosure of Invention
The invention aims to solve the topology abstraction problem in the automatic switching optical network with the layered multi-domain structure and the distortion problem generated by asymmetric link state parameters in the network; the tree topology abstraction method of the triangular matrix type is provided, the space complexity after the topology abstraction is still O (| B |), and the information accuracy is guaranteed to the maximum extent.
The technical scheme adopted by the invention to realize the technical purpose is as follows.
A spanning tree topology abstract method applied to an asymmetric network forms a fully connected graph abstraction topology of a boundary node by constructing a logical link (u, v) between each pair of boundary nodes in an original topology
Figure C20051012410600082
It is characterized in that: the step of generating the topological abstract of the tree is,
step 1, abstracting topology based on the full connectivity graph
Figure C20051012410600083
Constructing undirected fully-connected graph abstract topology M uAnd undirected fully-connected graph abstract topology M l Constructed undirected fully connected graph abstract topology M u And undirected fully connected graph abstraction topology M l The rule that only part of the logical links conform to the above rule is that each side in the abstract topology of the fully connected graph satisfies the rule of a triangle inequality;
step 2, constructing an undirected fully-connected graph abstract topology M u And undirected fully-connected graph abstract topology M l Respectively, denoted as a minimum spanning tree topology T u And a minimum spanning tree topology T l For logical links not on the two minimum spanning tree topologies, a lower bound on their weights can be obtained;
step 3, based on the minimum spanning tree topology T u Constructing a directed tree abstract topology
Figure C20051012410600091
Topology T of minimum spanning tree u Each undirected logical link on (A) is replaced by a directed tree abstract topology
Figure C20051012410600092
A pair of directed logical links on, wherein
Figure C20051012410600093
The weight value of each directed logic link on the link is respectively connected with the abstract topology of the full connectivity graph
Figure C20051012410600094
The weights of the corresponding directed logical links are the same. This is due to the undirected fully connected graph abstraction topology M u And undirected fully connected graph abstraction topology M l The other part of the logical links do not accord with the rule that each edge of the abstract topology of the full connectivity graph meets the triangle inequality, so that the upper bound of the weight of the logical links which are not on the two minimum spanning tree topologies can be obtained;
step 4, obtaining 3 tree-shaped abstract topologies which are directed tree-shaped abstract topologies
Figure C20051012410600095
Minimum spanning tree topology T u And a minimum spanning tree topology T l And the three are issued to other routing domain nodes.
The invention is in the abstract topology of the full connectivity graph
Figure C20051012410600096
In the logical link, the direction is pointed from small to large according to the node number and is constructed in the undirected fully-connected graph abstract topology M u In the method, the direction is pointed from large to small according to the node number and is constructed in the undirected full-connectivity graph abstract topology M l In (1).
The invention discloses a full connectivity graph abstract topology
Figure C20051012410600097
The weight value of each logic link in the network is respectively connected with the undirected full connectivity graph abstract topology M u Undirected fully connected graph abstract topology M l Corresponding respective logic inThe weights of the edit links are equal in value.
The minimum spanning tree topology T of the invention u Minimum spanning tree topology T l The weight value of each logical link is respectively connected with the undirected full connectivity graph abstract topology M u Undirected fully connected graph abstract topology M l Middle pairThe weights of the corresponding logical links are equal in value.
The invention relates to a directed tree abstract topology
Figure C20051012410600101
The weight value of each logic link in the network is respectively connected with the abstract topology of the full connectivity graph
Figure C20051012410600102
The weights of the corresponding logical links in the group are equal.
The invention provides the abstract topology of the full connectivity graph
Figure C20051012410600103
Wherein a logical link is not included in said directed tree abstract topologyMinimum spanning tree topology T u And a minimum spanning tree topology T l In any of the above, the upper and lower bounds of the logical link weight may then be obtained by,
step 1, the upper bound of the weight can be calculated by a directed tree abstract topology
Figure C20051012410600105
The node in the node B obtains the weight of the unique path between the two nodes on the logical link, and the two nodes of the logical link are set as a node u and a node v;
step 2, if the number of the node u is less than the number of the node v, the lower bound of the weight can be obtained by generating a tree topology T according to the minimum u Obtaining a logic link weight value with the maximum weight value on the unique path between the upper node u and the node v;
step 3, if the number of the node u is larger than the number of the node v, the lower bound of the weight can be determined according to the minimum spanning tree topology T l And obtaining the logic link weight with the maximum weight on the unique path between the upper node u and the node v.
When the only path between two end nodes of the logical link (u, v) on the spanning tree abstract topology has only one middle node, the invention sets the third node except the node u and the node v as the node r, and can obtain the upper bound and the lower bound of the weight of the logical link (u, v) and the logical link (v, u) according to the following steps, wherein the serial number of the node r is less than the serial numbers of the node u and the node v,
step 1, the upper bound of the weight of the logical link (u, v) is the sum of the weight of the logical link (u, r) and the weight of the logical link (r, v), and the upper bound of the weight of the logical link (v, u) is the sum of the weight of the logical link (v, r) and the weight of the logical link (r, u);
step 2, when the number of the node u is smaller than the number of the node v, comparing the weight value of the logical link (r, u) with the weight value of the logical link (r, v), wherein the large weight value is the lower bound of the weight value of the logical link (u, v);
and 3, when the number of the node u is larger than the number of the node v, comparing the weight value of the logical link (r, u) with the weight value of the logical link (r, v), wherein the large weight value is the lower bound of the weight value of the logical link (v, u).
Once the upper and lower bounds of the logic link weight lost in the process of generating the tree topology abstraction are obtained, the single-point approximation algorithm can be applied to decode.
Assuming that the number of node u is less than node v, i.e., u < v, then the topology M is abstracted for undirected fully-connected graphs u And M l Respectively have the following components in percentage by weight,
Figure C20051012410600111
Figure C20051012410600112
wherein w Mu (u, v) and w Ml (u, v) is allocated to M u And M l Of each of the undirected links (u, v). Let M u The decoded link weight is denoted as w Mu * (u, v), and M l The decoded link weight value is denoted as w Ml * (u, v). Due to full connectivity graph abstract topologyThe direction of each link has been implied at M u And M l Thus can obtain
Figure C20051012410600114
The decoded weight of each link in the system is as follows:
Figure C20051012410600115
due to M u And M l The above partial logical links do not satisfy the triangle rule, but the SP algorithm cannot be applied to M u And M l The above.
Directed fully-connected graph abstract topology
Figure C20051012410600116
The weight value of each directed logical link (u, v) in (b) is represented as w (u, v).
Based on T u Constructed directed tree abstract topology
Figure C20051012410600121
Will T u Each undirected logical link in the above is replaced by a pair of directed logical links, and the weight of each directed logical link is as follows:
Figure C20051012410600122
this method of dealing with asymmetric networks is called a Triangular Matrix (TM) method because it requires the acquisition of the upper and lower triangular matrices of a directed graph.
Due to the adoption of the measures, the invention has the following advantages and effects: the invention can carry out topology abstraction on the state parameters of the asymmetric links, so that all asymmetric information can be contained in the abstract topology; the accuracy of the information is guaranteed to the maximum extent; limiting the spatial complexity to O (| B |); the simulation result shows that the performance of the method is greatly superior to that of the traditional asymmetric network topology abstract method (AS).
Drawings
FIG. 1 is a schematic diagram of a fully connected graph abstract topology of a symmetric network;
FIG. 2 is a schematic diagram of a fully connected graph abstract topology of an asymmetric network;
FIG. 3 is a non-directional fully-connected graph M of an embodiment of the invention u A schematic diagram of (a);
FIG. 4 is a non-directional fully connected graph M of an embodiment of the present invention l A schematic diagram of (a);
FIG. 5 is a minimum spanning tree topology T of an embodiment of the present invention u A schematic diagram of (a);
FIG. 6 is a minimum spanning tree topology T of an embodiment of the present invention l A schematic diagram of (a);
FIG. 7 is a directed tree abstraction topology of an embodiment of the present invention
Figure C20051012410600123
A schematic diagram of (a);
FIG. 8 is a graph of number of false receptions versus delay constraint;
FIG. 9 is a graph of a number of false rejects versus a delay constraint;
fig. 10 is a graph of number of errors (rejected + received) versus delay constraint.
Detailed Description
The invention is further illustrated by the following examples in conjunction with the drawings.
In fig. 1, a fully connected graph abstract topology of a symmetric network is shown, with 3 nodes and 3 undirected links, with shortest path weights between nodes of 1 and 2, 10 between nodes 2 and 3, and 20 between nodes 2 and 3, respectively.
In FIG. 2, a full-connectivity abstract topology of an asymmetric network is shown, in which a logical link is constructed between each pair of boundary nodes in the original topology to form a full-connectivity abstract topology of boundary nodes
Figure C20051012410600131
Fully connected graph abstract topology
Figure C20051012410600132
The weight of the six logical links on the node is W (1,2) =10, W (1,3) =10, W (2,1) =1,W (3,1) =10, W (2,3) =10, W (3,2) =20.
Compared with a symmetric network, the asymmetric network increases the information quantity, not only doubles the weight number of the associated links with each node pair, but also increases the direction information of the links corresponding to each weight. Thus, the amount of information in an asymmetric network is 3 times that in a symmetric network.
In a symmetric network, only 1 integer 1 representing the link weight needs to be associated with node pairs 1 and 2. However, in an asymmetric network, a three-dimensional vector (1, 10,0) needs to be associated between node pair 1 and 2. Where 1 and 10 represent the weight of the link, and 0 indicates that a greater weight is associated with a link pointing from a small numbered node to a large numbered node.
The steps of generating the tree topology abstraction refer to fig. 3, fig. 4, fig. 5, fig. 6, fig. 7.
Obtaining a full connectivity graph abstract topology from an original topology
Figure C20051012410600133
The spanning tree topology abstraction step is as follows:
step 1, constructing an undirected full connectivity graph abstract topology M according to formulas (4) and (5) u And M l Undirected fully connected graph abstract topology M u Abstracting topology for fully connected graph
Figure C20051012410600134
And M is l Is composed of
Figure C20051012410600141
The lower triangular topological matrix of (1).
Constructed undirected fully-connected graph abstract topology M u And M l The rule that the partial logic links conform to is that all the edges in the abstract topology of the full connectivity graph meet the rule of a triangle inequality.
In fig. 3 and 4, the weight of each logical link is:
Figure C20051012410600142
Figure C20051012410600143
Figure C20051012410600144
Figure C20051012410600145
Figure C20051012410600147
fully connected graph abstract topology
Figure C20051012410600148
The weight of each logic link in the network is respectively compared with the abstract topology M of the undirected full connectivity graph u 、M l The weights of the corresponding logical links in the network are equal in value.
Step 2, respectively constructing M u And M l Minimum spanning tree topology T of u And T l
In the case of figures 5 and 6 of the drawings,
minimum spanning tree topology T u 、T l The weight of each logical link is respectively compared with the undirected full connectivity graph abstract topology M u 、M l The weights of the corresponding logical links in the group are equal in value. For logical links that are not on both minimum spanning tree topologies, a lower bound on their weights may be obtained.
Step 3, the minimum spanning tree topology T is processed u Each undirected logical link is replaced by a pair of directed logical links to construct a directed tree abstract topology
Figure C20051012410600149
In FIG. 7, there is a directed tree abstraction topology
Figure C200510124106001410
The weight value of each logic link in the network is respectively abstracted with the full connectivity graph
Figure C200510124106001411
The weights of the corresponding logical links in the group are equal. The weight value of each logical link is:
Figure C200510124106001412
Figure C200510124106001414
Figure C200510124106001415
step 4, generating three tree-shaped abstract topologies T u ,T l Andto nodes of other routing domains in the asymmetric network.
And the other routing domain nodes which receive the abstract topology obtain the upper and lower weight bounds of the logical links (2,3) and (3,2) according to the following steps.
Step 4.1, the weight values of the logical links (2,3) and (3,2) whose upper bounds are the unique paths between node pair 2 and 3 and node pair 3 and 2 are obtained according to FIG. 7,
w ub (2,3)=w(2,1)+w(1,3)=1+10=11,
w ub (3,2)=w(3,1)+w(1,2)=10+10=20。
step 4.2, because 2 is less than 3, the lower bound of the weight of the link (2,3) obtained according to fig. 5 is the link weight with the maximum weight on the unique path between nodes 2 and 3,
w lb (u,v)=max(w(1,2),w(1,3))=max(10,10)=10。
step 4.3, since 3 is greater than 2, the weight lower bound of the link (3,2) obtained according to fig. 6 is the link weight with the largest weight on the unique path between nodes 3 and 2,
W lb (3,2)=max(w(2,1),w(3,1))=max(1,10)=10。
once the upper and lower bounds of the logic link weight values lost in the tree topology abstraction process are obtained, a single-point approximation algorithm can be applied for decoding.
The performance of the proposed TM method was analyzed by simulation and compared to the AS method proposed in the above-mentioned document. In the simulation, each service request is assumed to have a time delay constraint, and the compared performance indexes are the number of false rejects (w.r.n.), the number of false accepts (w.a.n.), and the number of false rejects (r. + a.) n in the network. The false rejection means that when the estimated delay value of the path is smaller than the delay constraint of the service request and the actual delay value is larger than the delay constraint of the service request, the service request is accepted by the source node, but is finally rejected because it is not feasible in the path establishment process. The false acceptance means that when the estimated delay value of the path is greater than the delay constraint of the service request and the actual delay value is less than the delay constraint of the service request, the service request can be actually supported but rejected by the source node. In the simulation, the false rejection number and the false acceptance number of all service requests after reaching the network are recorded and added to compare the comprehensive performance of the two algorithms.
A randomly generated 300-node network topology was used in the simulation. The network comprises 10 domains, and each domain comprises 30 nodes on average. For each bidirectional link, an integer between 1 and 5 and an integer between 15 and 20 are randomly generated as the delay values of the two directional links. The link direction corresponding to each delay value is randomly selected. The connection arrival rate of the network is poisson distribution, and the connection duration is exponential distribution. The delay constraint for the service request is increased from 4 to 25 at a rate of step 3.
In fig. 8, 9 and 10, the false acceptance number, false rejection number, and false (reject + accept) number of the two abstract algorithms are shown, respectively, where the data bar with horizontal fill lines represents the TM method and the data bar with diagonal fill lines represents the AS method. AS can be seen from the three figures, TM is much smaller than AS regardless of the performance index. This is because the TM algorithm completely preserves the network's asymmetry information by constructing three spanning tree abstract topologies, whereas the AS algorithm completely discards this information. Moreover, partial links in the abstract topology of the symmetrical fully-connected graph constructed by the AS algorithm lose the triangle inequality property, so that the performance of the SP optimization algorithm is influenced, and the TM algorithm thoroughly solves the problem. The asymmetrical network topology abstract method provided by the patent can greatly reduce the number of routing decision errors caused by inaccurate topology information of the source node and improve the performance of the network.

Claims (7)

1.一种应用于不对称网络中的生成树拓扑抽象方法,通过在原拓扑中的每对边界节点之间构建一条逻辑链路(u,v),形成一个边界节点的全连通图抽象拓扑
Figure C2005101241060002C1
其特征为:所述的生成树拓扑抽象步骤为,
1. A spanning tree topology abstraction method applied to an asymmetric network, by constructing a logical link (u, v) between each pair of boundary nodes in the original topology to form a fully connected graph abstract topology of boundary nodes
Figure C2005101241060002C1
It is characterized in that: the described spanning tree topology abstraction step is,
步骤[1],基于所述的全连通图抽象拓扑
Figure C2005101241060002C2
构建无向全连通图抽象拓扑Mu和无向全连通图抽象拓扑Ml,在全连通图抽象拓扑中的逻辑链路中,将方向按节点编号从小指向大的,构建在所述的无向全连通图抽象拓扑Mu中,将方向按节点编号从大指向小的,构建在所述的无向全连通图抽象拓扑Ml中,构建的无向全连通图抽象拓扑Mu和无向全连通图抽象拓扑Ml上只有部分逻辑链路符合的法则为,全连通图抽象拓扑中各条边满足三角形不等式的法则;
Step [1], based on the abstract topology of the fully connected graph
Figure C2005101241060002C2
Construct the abstract topology M u of undirected fully connected graph and the abstract topology M l of undirected fully connected graph, in the abstract topology of fully connected graph In the logical link in , point the direction from small to large according to the node number, build in the abstract topology M u of the undirected fully connected graph, and direct the direction from large to small according to the node number, and construct the In the fully connected graph abstract topology M l , the constructed undirected fully connected graph abstract topology M u and the undirected fully connected graph abstract topology M l conform to the rule that only part of the logical links are, each link in the fully connected graph abstract topology The sides satisfy the laws of the triangle inequality;
步骤[2],构建无向全连通图抽象拓扑Mu和无向全连通图抽象拓扑Ml的最小生成树拓扑,分别表示为最小生成树拓扑Tu和最小生成树拓扑Tl,对于不在这两个最小生成树拓扑上的逻辑链路,可得到它们权值的下界;In step [2], construct the minimum spanning tree topology of the abstract topology M u of the undirected fully connected graph and the abstract topology M l of the undirected fully connected graph, which are denoted as the minimum spanning tree topology T u and the minimum spanning tree topology T l respectively. The logical links on the two minimum spanning tree topologies can get the lower bound of their weights; 步骤[3],基于最小生成树拓扑Tu构建一个有向树形抽象拓扑将最小生成树拓扑Tu和Tl上的每一条无向逻辑链路都替换为有向树形抽象拓扑
Figure C2005101241060002C5
上的一对有向逻辑链路,这是由于无向全连通图抽象拓扑Mu和无向全连通图抽象拓扑Ml上的另一部分逻辑链路不符合全连通图抽象拓扑的各条边满足三角形不等式的法则,这样是为了能得到不在这两个最小生成树拓扑上的逻辑链路权值的上界;
Step [3], construct a directed tree abstract topology based on the minimum spanning tree topology T u Replace every undirected logical link on the minimum spanning tree topology T u and T l with a directed tree abstract topology
Figure C2005101241060002C5
A pair of directed logical links on , this is because the undirected fully connected graph abstract topology M u and another part of the logical links on the undirected fully connected graph abstract topology M l do not conform to the edges of the fully connected graph abstract topology Satisfy the rule of the triangle inequality, so as to obtain the upper bound of the logical link weight not on the two minimum spanning tree topologies;
步骤[4],于是得到3个树形抽象拓扑,为有向树形抽象拓扑
Figure C2005101241060002C6
最小生成树拓扑Tu和最小生成树拓扑Tl,将三者发布到其他路由域节点上。
Step [4], then get 3 tree-shaped abstract topologies, which are directed tree-shaped abstract topologies
Figure C2005101241060002C6
Minimum spanning tree topology T u and minimum spanning tree topology T l , and publish the three to other routing domain nodes.
2.根据权利要求1所述的一种应用于不对称网络中的生成树拓扑抽象方法,其特征为:所述的全连通图抽象拓扑
Figure C2005101241060003C1
中各个逻辑链路的权值分别和所述的无向全连通图抽象拓扑Mu、无向全连通图抽象拓扑Ml中对应的各个逻辑链路的权值在数值上相等。
2. A kind of spanning tree topology abstraction method applied in asymmetric network according to claim 1, characterized in that: the fully connected graph abstract topology
Figure C2005101241060003C1
The weights of each logical link in are numerically equal to the weights of corresponding logical links in the undirected fully connected graph abstract topology M u and the undirected fully connected graph abstract topology M l respectively.
3.根据权利要求1所述的一种应用于不对称网络中的生成树拓扑抽象方法,其特征为:所述的最小生成树拓扑Tu、最小生成树拓扑Tl的各个逻辑链路的权值分别和所述的无向全连通图抽象拓扑Mu、无向全连通图抽象拓扑Ml中对应的各个逻辑链路的权值在数值上相等。3. a kind of spanning tree topology abstraction method that is applied in asymmetrical network according to claim 1, is characterized in that: the each logic link of described minimum spanning tree topology T u , minimum spanning tree topology T l The weights are numerically equal to the weights of the corresponding logical links in the abstract topology M u of the undirected fully connected graph and the abstract topology M l of the undirected fully connected graph. 4.根据权利要求3所述的一种应用于不对称网络中的生成树拓扑抽象方法,其特征为:所述的有向树形抽象拓扑
Figure C2005101241060003C2
中各个逻辑链路的权值分别和所述的全连通图抽象拓扑
Figure C2005101241060003C3
中对应的各个逻辑链路的权值相等。
4. A kind of spanning tree topology abstraction method applied in asymmetric network according to claim 3, characterized in that: said directed tree abstract topology
Figure C2005101241060003C2
The weights of each logical link in and the abstract topology of the fully connected graph are respectively
Figure C2005101241060003C3
The weights of the corresponding logical links in are equal.
5.根据权利要求1所述的一种应用于不对称网络中的生成树拓扑抽象方法,其特征为:如果所述的全连通图抽象拓扑
Figure C2005101241060003C4
中有一条逻辑链路不包含在所述的有向树形抽象拓扑
Figure C2005101241060003C5
最小生成树拓扑Tu和最小生成树拓扑Tl中的任何一个中,则可以通过如下步骤得到该逻辑链路权值的上界和下界,
5. A kind of spanning tree topology abstraction method applied in asymmetric networks according to claim 1, characterized in that: if the fully connected graph abstract topology
Figure C2005101241060003C4
There is a logical link in that is not included in the directed tree abstract topology
Figure C2005101241060003C5
In any one of the minimum spanning tree topology T u and the minimum spanning tree topology T l , the upper bound and lower bound of the logical link weight can be obtained through the following steps,
步骤[1],权值的上界可以通过计算有向树形抽象拓扑中所述的节点对逻辑链路上两节点之间的唯一路径的权值得到,设逻辑链路两节点为节点u和节点v;In step [1], the upper bound of the weight can be calculated by calculating the directed tree abstract topology The weight of the node described in to the unique path between two nodes on the logical link is obtained, assuming that the two nodes of the logical link are node u and node v; 步骤[2],如果节点u的编号小于节点v的编号,权值下界可以通过根据最小生成树拓扑Tu上节点u和节点v之间唯一路径上权值最大的逻辑链路权值得到;Step [2], if the number of node u is less than the number of node v, the lower bound of the weight can be obtained by the weight of the logical link with the largest weight on the unique path between node u and node v on the minimum spanning tree topology T u ; 步骤[3],如果节点u的编号大于节点v的编号,权值下界可以通过根据最小生成树拓扑Tl上节点u和节点v之间唯一路径上权值最大的逻辑链路权值得到。Step [3], if the number of node u is greater than that of node v, the lower bound of the weight can be obtained by the weight of the logical link with the largest weight on the unique path between node u and node v on the minimum spanning tree topology T1 .
6.根据权利要求1所述的一种应用于不对称网络中的生成树拓扑抽象方法,其特征为:当所述的逻辑链路(u,v)的两个端节点之间在生成树抽象拓扑上的唯一路径只有一个中间节点时,设除节点u和节点v外的第三个节点为节点r,可根据下面步骤得到逻辑链路(u,v)和(v,u)的权值上界和下界,其中,节点r的编号均小于节点u和节点v的编号,6. a kind of spanning tree topology abstraction method that is applied in asymmetrical network according to claim 1 is characterized in that: when two terminal nodes of described logical link (u, v) are in spanning tree When the only path on the abstract topology has only one intermediate node, let the third node besides node u and node v be node r, and the weights of logical links (u, v) and (v, u) can be obtained according to the following steps Value upper bound and lower bound, where the number of node r is smaller than the number of node u and node v, 步骤[1],逻辑链路(u,v)的权值上界为逻辑链路(u,r)的权值与逻辑链路(r,v)的权值之和,逻辑链路(v,u)的权值上界为逻辑链路(v,r)的权值与逻辑链路(r,u)的权值之和;Step [1], the upper bound of the weight of the logical link (u, v) is the sum of the weight of the logical link (u, r) and the weight of the logical link (r, v), the logical link (v , the upper bound of the weight of u) is the sum of the weight of the logical link (v, r) and the weight of the logical link (r, u); 步骤[2],当节点u的编号小于节点v的编号,比较逻辑链路(r,u)的权值与逻辑链路(r,v)的权值的大小,大的权值为逻辑链路(u,v)的权值的下界;Step [2], when the number of node u is less than the number of node v, compare the weight of the logical link (r, u) with the weight of the logical link (r, v), and the larger weight is the logical link The lower bound of the weight of the road (u, v); 步骤[3],当节点u的编号大于节点v的编号,比较逻辑链路(r,u)的权值与逻辑链路(r,v)的权值的大小,大的权值为逻辑链路(v,u)的权值的下界。Step [3], when the number of node u is greater than the number of node v, compare the weight of the logical link (r, u) with the weight of the logical link (r, v), the larger weight is the logical link The lower bound of the weight of the path (v, u). 7.根据权利要求6所述的一种应用于不对称网络中的生成树拓扑抽象方法,其特征为:一旦得到了这些所述的生成树拓扑抽象过程中丢失的所述的逻辑链路权值的上界和下界,即可应用单点逼进算法进行解码。7. A method for abstracting spanning tree topology applied in asymmetric networks according to claim 6, characterized in that: once the lost logical link rights in the process of abstracting spanning tree topology are obtained, The upper and lower bounds of the values can be decoded using the single-point approximation algorithm.
CNB2005101241063A 2005-11-25 2005-11-25 A Spanning Tree Topology Abstraction Method Applied to Asymmetric Networks Expired - Fee Related CN100369432C (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CNB2005101241063A CN100369432C (en) 2005-11-25 2005-11-25 A Spanning Tree Topology Abstraction Method Applied to Asymmetric Networks

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CNB2005101241063A CN100369432C (en) 2005-11-25 2005-11-25 A Spanning Tree Topology Abstraction Method Applied to Asymmetric Networks

Publications (2)

Publication Number Publication Date
CN1787470A CN1787470A (en) 2006-06-14
CN100369432C true CN100369432C (en) 2008-02-13

Family

ID=36784789

Family Applications (1)

Application Number Title Priority Date Filing Date
CNB2005101241063A Expired - Fee Related CN100369432C (en) 2005-11-25 2005-11-25 A Spanning Tree Topology Abstraction Method Applied to Asymmetric Networks

Country Status (1)

Country Link
CN (1) CN100369432C (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009124419A1 (en) * 2008-04-10 2009-10-15 郎讯科技公司 Topology abstraction method, topology abstraction apparatus and route controller
CN115242656B (en) * 2022-06-27 2023-07-21 新华三技术有限公司 Communication establishment method and device
CN117318516A (en) * 2023-09-25 2023-12-29 电子科技大学 A multi-port inverter topology derivation method based on directed graph

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1529429A (en) * 2003-09-30 2004-09-15 ���ͨ�ſƼ��ɷ����޹�˾ Method for determining abstract topological link attribute for optical network hierarchical route
US20050187946A1 (en) * 2004-02-19 2005-08-25 Microsoft Corporation Data overlay, self-organized metadata overlay, and associated methods

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1529429A (en) * 2003-09-30 2004-09-15 ���ͨ�ſƼ��ɷ����޹�˾ Method for determining abstract topological link attribute for optical network hierarchical route
US20050187946A1 (en) * 2004-02-19 2005-08-25 Microsoft Corporation Data overlay, self-organized metadata overlay, and associated methods

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
A spanning Tree-Based QOS Aggregation AlgorithminHierarchical ASON. Lei Lei, Yuefeng Ji.IEEE COMMUNICATIONS LETTERS,Vol.9 No.5. 2005 *

Also Published As

Publication number Publication date
CN1787470A (en) 2006-06-14

Similar Documents

Publication Publication Date Title
Korkmaz et al. Source-oriented topology aggregation with multiple QoS parameters in hierarchical networks
CA2162491C (en) Method for efficient aggregation of link metrics
US9225628B2 (en) Topology-based consolidation of link state information
US20100232322A1 (en) Node, network system, frame transfer method, and frame transfer program
CN111245722B (en) SDN data center network flow forwarding method based on genetic algorithm
CN110460546B (en) A Data Acquisition Method Based on Network-on-Chip
CN107465966B (en) Topology reconstruction control method for optical network
CN114745227B (en) Electric power business network slicing time delay calculation method and device based on FlexE and SPN technologies
CN105357132B (en) A kind of multiple domain ASON damages based on hypergraph model perceive multicast route method
CN104901886A (en) Wide-area protection communication circuitous channel reconstruction algorithm in view of delay and traffic balance
CN105553855B (en) Method and system for dynamically adjusting spanning tree topology of underlying network
CN108400936A (en) Information Network method for routing based on MPLS
CN101370312A (en) A Construction Method of Hybrid Switched Optical Network Based on Loop
CN100369432C (en) A Spanning Tree Topology Abstraction Method Applied to Asymmetric Networks
CN106789642A (en) A kind of dynamic load balancing method based on SDN
CN110139173A (en) A kind of network dividing area method reducing optical transfer network end-to-end time delay
JPH0983546A (en) Route selecting method/device and communication network design method/device
CN110677306B (en) Network topology replica server configuration method and device, storage medium and terminal
CN102026051A (en) Layered virtual topology-based cross-granularity layer survivability method
CN102137002A (en) Load sharing method and device for border gateway protocol (BGP)
CN102035656A (en) Method for realizing multicast system of overlay network based on agency
CN101102616A (en) Shortest path searching method and device under multi-restraint conditions in automatic switching optical network
Lei et al. A spanning tree-based QoS aggregation algorithm in hierarchical ASON
Lei et al. Optimization method of spanning tree aggregation for hierarchical QoS routing
CN113206788B (en) Service quality mapping method and device based on SR and storage medium

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20080213

Termination date: 20141125

EXPY Termination of patent right or utility model