Reliability-Aware SFC Protection by Using Nodes with Spare Resources

Network Function Virtualization (NFV) can reduce expenses in network services deployment while enhancing flexibility, adaptivity, and reliability of network services. To optimize resource allocation, each service request will be expressed as a service function chain (SFC), where each SFC may include multiple virtualized network functions (VNFs). Then, the SFC paths are calculated to improve the overall performance of network services. Any VNF failure within an SFC may result in service interruption. Installing backup VNFs is an effective approach to improve the reliability of SFCs, but previous approaches may consume substantial amount of resources to achieve only limited reliability. In this work, we propose a novel approach to improve the reliability of SFCs without excessive backup resource consumption. Our approach generates both primary and backup paths for each SFC simultaneously to meet the requirements of reliability, where the backup node of an SFC can be the primary nodes of other SFCs. The simulation results show that the proposed approach can achieve high reliability with high acceptance ratios. Moreover, the backup resource can be reduced as compared to previous algorithms.