The Design And Implementation Of CR Project

With the fast development of computer and communication technology, Internet has become the important resource in current society. However, with the evolution of network, on one hand, the network-based failure sensitive applications and services such as IP phone, online transaction, and video conference were emerging; the network carries much more traffic than ever. In this situation, there is more and more demands for the IP routing to recover from failure. Studies have found that the timers in OSPF can damp the short time route flap. Therefore, with the increase of all kinds of real-time network service, the exsiting flap damping mechanism of routing protocols can no longer satisfy the requirements.Aiming at the problems metioned above, the subject of this article analysises the limitness of most widely used protocol OSPF, developes a novel adaptive route control protocol-CR, which was used to control OSPF. When the network failure occurs, CR can estimate the destroy degree of network and change the convergence rate of OSPF dynamically. Through the upper methods, CR minimizes the loss to a considerable extent which caused by the link failure, and enhances the adaptiveness of routing protocol.Based on the research, we implemented CR. This implementation followes the principle of high cohesion low coupling, clearly defines the duty of modules, definitely designs the interfaces between modules. The inner design of modules are accorded to simple and high efficiency, we made efforts to simplify procedures in order to alleviate the pressure of coding and debugging. The tests included unit tests and system tests in order to ensure correctness and reliability. This implementation based older implementation of CR, the problems of module devide and procdure designation of the older version had been revised. The main contents of this dissertation are listed as follows:(1) Analyzed the features and principles of OSPF and presented a thorough study of OSPF fault process mechanism. Then, presented the insufficiency of this mechanism.(2)Analysed self-adaptive routing technology and gave a detailed analysis and introduction about implementation of self-adaptive routing technology.(3) Tests were carried out in scenarios of different failure type then a detailed study and comparison on the results was introduced.