Research On Internet Routing Protection

Link failures occur frequently on the Internet, while the proliferation of the real-time and loss-sensitive applications today is far less tolerant to packet loss. As a result,the self-healing ability of the existing routing protocols is facing big challenges and theInternet routing has a big self-healing problem. Among the solutions that have beenproposed to solve the self-healing problem of the Internet routing, routing protection isone of the most efective that have good performance and can be easily implemented.Therefore, we focus on routing protection in both the intra-domain and inter-domainnetworks of the Internet in this dissertation. We study the basic problems in routingprotection via establishing an Internet routing protection framework and improve the self-healing performance of the Internet by extending current routing protocols. The maincontributions of this dissertation are listed as follows.1. We propose an Internet routing protection framework to study the essence of rout-ing protection. The important elements that afect routing protection are studied througha routing protection model. The network state transition model under routing protec-tion is proposed to analyze the network state transition under diferent kinds of routingprotection schemes from the aspects of both data plane and control plane. Finally, theevaluation system of routing protection is proposed to evaluate protection schemes and toguide future design.2. We propose a selective link protection scheme for intra-domain networks undersingle link failure situation. We measure network failures in real networks and analyzethe characteristics of intra-domain link failures. Based on the link failure characteris-tics found in the measurement, we can well balance the protection performance and theprotection cost by carefully selecting the links which are more critical to protect. Thesimulation results show that this algorithm can dramatically reduce the protection costwhile ensuring the protection performance.3. We propose a multi-link-failure-oriented cost-efcient routing protection schemefor intra-domain networks. We first analyze the cause of multi-link failures and resourceassignment patterns of protection schemes. Then, the network model under multi-linkfailure situation is designed, and a multi-link-failure-oriented cost-efcient routing pro- tection scheme is proposed. The experimental results show that, the algorithm can guar-antee good protection performance and reduce the protection cost. Besides, the algorithmperforms better in situations where there are fewer simultaneous failed links.4. We propose an inter-domain protection scheme based on abnormality identi-fication and random methods. The abnormality identification method we propose canidentify the abnormal routing events just from last hop and destination address of datapackets. We’ve designed two protection algorithms based on abnormality identificationand random methods to protect the data packets that encounter abnormal routing events.The results of both the simulation and the real implementation experiment show that thealgorithms have good protection performance and can be incrementally implemented.