A Dependability Case Approach to the Assessment of IP Networks

IP networks, composing the Internet, form a central part of the information infrastructure of the modern society. Integrated approaches to the assessment of their dependability are, however, only emerging. This paper presents three contributions for meeting this challenge. First, we propose an adaptation of the safety case methodology, a 'dependability case' approach, as a practical form of organizing heterogeneous information concerning the dependability of a large communication network. The idea is to build structured argumentation for the support of dependability claims, making use of various kinds of evidences. Second, we suggest a conceptual frameworkfor considering the dependability of IP networks in an integrated way. Third, we propose to structure dependability cases of IP networks according to the main aspects of dependability, rather than structural units or layers of the network. The proposed methodology is tested on the Finnish University Network and found promising.