Research On The Survivability Technologies Of IP Network

IP routing makes the routers construct an end to end connection between two communication points in a network or between the networks. IP routing is robust and it can automatically recover from almost all types of failure.However, with the evolution of network, on one hand, the network-based failure sensitive applications and services such as IP phone, video conference, and online trasaction emerge and prosper. On the other hand, the network carries much more traffic than ever. In this situation, there is more demand for the IP routing to recover from failure.The ability that a network can provide service in face of changllenges such as failure and attack is concerned in the survivability study. Though the researches on network survivabiltiy have a relative long history, with the evolution of network, the focuses of survivabilty change. The researches on survivabilty of IP network as a subset of research onnetwork survivablity are relatively new and many issues are needed to be investigated, such as follows : An efficient model to evaluate the survivablity of IP network is needed; The failure handling technoloies in IP network are now focus on single link failures and the load balance and quality of serveice are not surpported in the process of failure recovery; There is little research work on the failure recovery in case of hash failure where multiple links and nodes may fail cocurrently.This thesis focuses on the issues above and carries out the following research:1) Established the evaluation model of the survivability of IP network: Differ from the traditional paradim of evaluating the newtork survivablity, a new model which consists of the parameters of IP routing dynamics such as convergence time, traffic model and congestion probability is proposed. The new model interprets the survivability of IP network in performance perspective and emphasises the ability that a network adjusts the traffic in case of failure.2) Established a fast failure recovery technology: Based on defletion routing, single link failure and node failure are promptly handled and loop-free routing is also guarenteed.Based on the proposed defletion routing technololgy, the combinations of Quality of service and load balancing with failure recovery techonlogy are investigated. The researches fall into the following two areas: (1) The intercrossing of surivability and load balance; (2) The intercrossing of surivability and Quality of service. The achievements are as following:(1) Supporting load balance in faliure recovery :A genetic algorithm based link weight assignment techonlogy is proposed to realize load balance under uncertain traffic model and apply it to defletion routing technology to achieve load balance goal.(2) Recoverying failure in QoS routing: A new the deflection routing technology is proposed to handle failures in QoS routing by promptly providing a backup path which satisfing the QoS constraints.3) Established failure hanling technology at hash failure scenario:(1) Failure handling based on connected dominating sets when links are unreliable: The network is partitioned into two parts by connected dominating sets. Multiple link failures are promptly recovered by dynamically repairing the connected dominating sets when the topolgoy changes.(2) Failure handling based on dynamic source routing when nodes and links are unreliable: Due to the similarity of wireless Ad hoc network and IP network in harsh scenarios.The paradiam of dynamic source routing is used to explore and provide a loop-free path to the destination so that multiple nodes failures and links failures are handled in harsh scenarios.