Research On Survivability Of Network Topologies

Network nodes which fail (be attacked) will change the structure of the network topology, and the changes of network topology may affect the whole of the network. If some key nodes fail (be attacked) in the network, the effect on network communication may be vital. In this paper, the network topologies survivability is the main topic. The research is mainly on three aspects in order to find the influence of changes of network topologies on network survivability. These three issues are node importance, network survivability and search nodes between any two nodes to interrupt these communication.Node importance is the main parameter to measure one node in the whole network topology. The node importance is divided into the global importance and local importance. This thesis put forward the two-divide algorithms used to evaluate the node importance of network topology Then the experiments are based on the simple topology, star network topology, mesh topology, fat tree topology and ARPA topology and other typical nodes importance were calculated by using the algorithm. The experimental results show that the proposed algorithm (1) Has a higher accuracy for the evaluation of the star topology. (2) The evaluation results of the node importance of the other topological nodes are consistent with the existing algorithms.Analysis of the structure characteristics of network topology shows that topological node average degree, network diameter, strongly connected region of the node degree distribution factors in the topology of the network survivability has apparent rules, and the influence law within the specified range is determined. This paper put forward a network survivability evaluation algorithm which is base on node's average degree, network diameter and strong connected node degree distribution, which is used to have a quantitative evaluation for survivability of the network. Network attack simulation example shows that the network Survivability algorithm (1) in the process of network attack node, choose the best attack nodes, in order to achieve the maximum damage effect on the network; (2) in the node substitution attack, and attack other equivalent node instead of some certain nodes.The key node selection algorithm is a search algorithm which can interrupt communication between any two nodes in the network topology. This paper put forward a search algorithm for the network topology, under the premise of the network topology structure. It can search for the nodes of all potential routes to interrupt communication between any two nodes. The three experiments are based on Fat tree network topology, ARPA topology and mesh topology, and these results verify the correctness and validity of the algorithm.