Reliability-Aware and Delay-Constrained Service Function Chain Orchestration in Multi-Data-Center Networks

A virtualized network service is usually realized via one or more service function chain(SFC) composed of a set of VNFs in an ordered sequence. SFC orchestration is critical to efficient 5G/6G service deployment in distributed cloud environment with various constraints such as QoS requirements. In this paper, we address the problem of deployment cost optimization oriented SFC orchestration in the multiple data centers environment with reliability and end-to-end delay constraints. The optimization issue is formulated as a Mixed Integer Linear Programming (MILP) model. Given the NP-hard of the problem, we propose a two-stage approach called Cost-aware, Delay-constrained and Reliability-constrained SFC Orchestration(CDRSO) for the large-scale networks. Extensive simulation results show that CASODP can achieve lower average cost than the existing method CADCSO. Moreover, The CRIM-based backup algorithm performs better than existing CCI-based backup algorithm. Specifically, CDRSO can achieve an average cost nearly 25% lower than CADCSO-CCI, and the acceptance rate is significant higher than CADCSO-CCI. Furthermore, CDRSO constantly outperforms CADCSO-CCI in different reliability requirements and with different SFC lengths.