Joint Resource Management and Flow Scheduling for SFC Deployment in Hybrid Edge-and-Cloud Network

Network Function Virtualization (NFV) migrates network functions from proprietary hardware to commercial servers on the edge or cloud, making network services more cost-efficient, manage-convenient, and flexible. To facilitate these advantages, it is critical to find an optimal deployment of the chained virtual network functions, i.e. service function chains (SFCs), in hybrid edge-and-cloud environment, considering both resource and latency. It is an NP-hard problem. In this paper, we first limit the problem at the edge and design a constant approximation algorithm named chained next fit (CNF), where a sub-algorithm called double spanning tree (DST) is designed to deal with virtual network embedding. Then we take both cloud and edge resources into consideration and create a promotional algorithm called decreasing sorted, chained next fit (DCNF), which also has a provable constant approximation ratio. The simulation results demonstrate that the ratio between DCNF and the optimal solution is much smaller than the theoretical bound, approaching an average of 1.25. Moreover, DCNF always has a better performance than the benchmarks, which implies that it is a good candidate for joint resource and latency optimization in hybrid edge-and-cloud networks.