Deploying Disaster-Resilient Service Function Chains Using Adaptive Multi-Path Routing

Network Function Virtualization (NFV) is a new technology that deploys network services and functions as software components in data centers and cloud environments. One of its key applications is Service Function Chain (SFC), which chains a set of Virtual Network Functions (VNFs) in a specific order to deliver a desired service. However, deploying NFV and SFC networks faces challenges, particularly in terms of disaster resiliency. This encompasses natural disasters and hardware failures, which can disrupt network operations and lead to service interruption or degradation across an entire disaster zone (DZ). Therefore, designing NFV and SFC networks that can withstand disasters while providing high levels of service availability and reliability is important. This paper presents a new method for protecting SFCs using adaptive multi-path routing. The proposed Multi-path Protection (MP) method has the advantage of reducing the amount of reserved bandwidth on backup paths by distributing SFC traffic over multiple DZ-disjoint working paths. The problem being addressed involves VNFs placement, routing SFCs, and implementing protection mechanisms. The objective is to minimize network resource consumption, including both the bandwidth used by request routing paths and the computing resources for VNF execution. To solve this multi-dimensional optimization problem, a path-adaptive and flow-based integer linear program (ILP) is proposed to provide the optimal solution in sall-size network settings. We also propose a heuristic approach that offers the near-optimal solution in a time-efficient way. Comprehensive simulation results show that the proposed MP strategy outperforms traditional Dedicated Protection (DP) in terms of bandwidth and processing resource consumption, resulting in a significant gain up to 20%.