The 4G of mobile networks is considered a technology-opportunistic and user-centric system combining the economical and technological advantages of
various transmission technologies. Part of its new architecture dubbed as the System Architecture Evolution, 4G mobile networks will implement an evolved packet core. Although this will provide various critical advantages, it will however expose telecom networks to serious IP-based attacks. One often adopted solution by the industry to mitigate such attacks is based on a centralized security architecture. This centralized approach nonetheless, requires large processing resources to handle huge amount of traffic, which results in a significant over dimensioning problem in the centralized nodes causing this approach to fail from achieving its security task.\\
In this thesis, we primarily contribute by highlighting on two Spam flooding attacks, namely RTP VoIP SPIT and SMTP SPAM and demonstrating, through simulations and comparisons, their feasibility and DoS impact on 4G mobile networks and subsequent effects on mobile network operators. We further contribute by proposing a distributed architecture on the mobile architecture that is secure by mitigating those attacks, efficient by solving the over dimensioning problem and cost-effective by utilizing `off the shelf' low-cost hardware in the distributed nodes. Through additional simulation and analysis, we reveal the viability and effectiveness of our approach
