The use of modeling and simulation to examine network performance under Denial of Service attacks

The methods that have been used in this thesis are an in-depth literature examination and an experimental tactic for evaluation and analysis. To carry out the investigation OPNET will be used for the modeling and simulation of computer/network security and computer network attacks. In order to obtain the background knowledge needed for this effort a Qualitative approach is used. Background information on modeling and simulation is required for creating accurate OPNET models. Two scenarios will be constructed in OPNET; one that shows how the network performs under ordinary conditions and the other scenario in which a network undergoes an attack from another network by means of a flooding attack. These scenarios have been built according to the details mentioned by Mattias Bjorlin in his thesis on Modeling and Simulation [19]. In the case of the two different scenarios, the independent variables will be the OPNET built-in parameters which are used while designing the models such as the HTTP which is kept as light browsing, FTP which is medium loaded, and Database which is medium loaded. The dependent variables will be the test for VPN and firewall, and the various other performance parameters such as the throughput and the delay. The graphs from the two scenarios will then be compared with the work done by the previous researcher and on this basis the models will be verified. The conclusion of this research would be based on the graphical analysis of the two scenarios discussed above.