Cost-effective and ddos-aware network function sharing models for next-generation networks

As next-generation communication networks evolve to meet increasingly diverse service requirements, optimizing resource efficiency and ensuring sustain- ability have become paramount. Network Function (NF) sharing has emerged as a promising solution for achieving both environmentally friendly and cost- effective resource allocation by maximizing resource utilization. However, main- taining Quality of Service (QoS) continuity and addressing security vulnerabilities together with NF sharing remain significant challenges. This thesis introduces a framework to optimize NF sharing for next-generation networks, with a focus on balancing cost efficiency with QoS and security. We propose a set of cost-efficient heuristics, CNFSH, along with its delay-aware version, D-CNFSH, to effectively manage the allocation and sharing of NFs. By prioritizing NF sharing, our ap- proach significantly reduces underutilized resources, lowers operational costs, and supports green network initiatives, all while ensuring QoS continuity through the use of a priority-aware load balancer (LB). A novel metric, the ratio of underuti- lized to allocated resources, demonstrates the effectiveness of this method, with results showing underutilization reduced from around 30% in NoShare schemes to less than 0.4% with D-CNFSH. Additionally, the thesis addresses the security concerns associated with NF sharing by introducing SliceScore, an NF sharing- aware DDoS filtering mechanism designed to mitigate resource exhaustion threats. Simulations indicate that SliceScore outperforms traditional filtering methods by leveraging slice-specific insights to enhance defense strategies. These contributions lay the foundation for designing sustainable, secure, and cost-efficient communi- cation networks in next-generation systems and pave the way for further research in the area.