Service Function Chain Deployment in NFV-Enabled Networks: A Comprehensive Survey

Service Function Chaining is a key enabler of efficient and flexible network service provisioning in Network Function Virtualization (NFV)-enabled networks. It orchestrates the deployment of an ordered set of Virtual Network Functions (VNFs) across physical infrastructure, ensuring seamless service delivery. NFV, by decoupling network functions from proprietary hardware, introduces scalability and cost efficiency but also brings challenges related to dynamic resource allocation, energy efficiency, and optimal utilization of network resources. This survey provides a detailed exploration of NFV architecture and the foundational concepts of SFC, highlighting the constraints and optimization challenges involved. It also presents various metrics to quantify the performance of SFC deployment. Further, it offers a comprehensive analysis of state-of-the-art SFC deployment approaches, focusing on delay-aware, cost-efficient, reliability-aware, resource-efficient, and load balance and throughput optimized methods. Furthermore, this work categorizes the SFC deployment problem across dimensions such as traffic characteristics, solution methodologies, and target environments, offering a structured perspective on existing solutions. Despite significant advancements, this study concludes that current SFC deployment approaches often face limitations in scalability, flexibility, and efficiency, hindering their real-world applicability. To address these gaps, the survey outlines ongoing research challenges and proposes future directions, emphasizing the need for innovative solutions to enhance resource allocation, improve service reliability, and tackle scalability issues in NFV-enabled networks. This work aims to serve as a reference point for researchers and practitioners striving to advance SFC deployment strategies in NFV contexts.