The Study Of IMS System Survivability In NGN

Survivability is first used by Barnes in 1993. The difference between survivability and traditional security research is that survivability not only pays attention to how to build a security network, but also focuses on the ability of providing service in unsafe environment. Survivable system must have 3 capabilities: Resistance, Recognition and Recovery. Network survivability has become a new direction of studies on network security.Now, the study of survivability focuses on network physical layer, seldom on control layer and application layer; This dissertation studies network control layer survivability, mainly brings forward a method and frame of analyzing system survivability on control layer and application layer. Firstly, this dissertation studies the interrelated domains of network survivability, including the process of network security technology development, definition elements, system primary characters, survivability measurement method, analysing method, applying domains, common acknowledgements, developing trends, implementing methods, etc, and builds a systematic theory framework of studies on network survivability. Secondly, this dissertation studies IMS system structure, functional modules, network interfaces, information order flow and security problem; and builds a systematic theoretic framework of studies on IMS system. Finally, under the direct of these theories discussed above,this dissertation sets up the model about IMS registering process, analyses it and gains performance parameters. It measures attack, imports attack in the model, analyses the influence of attack on it, gains the parameters measuring the model survivability, and brings forward several methods of improving system survivability.