Containerized Design and Realization of Network Functions Virtualization for a Light-Weight Evolved Packet Core Using OpenAirInterface

In recent years, network functions virtualization (NFV) has been well perceived as the driving force behind innovations of the 5G system, such as slicing precious system resources for differential service needs. In this paper, we propose a container-based design of virtual evolved packet core (vEPC) slice and its light-weight version (LW-vEPC) based on the OpenAirInterface (OAI) software package. We have successfully containerized, and thus virtualized, the EPC component functions into two separate containers: the control-plane (CP) container for virtual home subscriber server (vHSS) and virtual mobility management entity (vMME), and the data-plane (DP) container for virtual serving and packet data network gateway (vSPGW). Via a joint configuration design of virtual linking, binding and bridging, including appropriate source and destination network address translation (SNAT and DNAT), both the intra-container and inter-container communications have been successfully realized. An OAI-based joint test of vEPC with a small-cell base station (ENB) has also been successfully demonstrated via a downlink video streaming showcase from the Internet to a cellular phone. The DP container itself can also perform as a LW-EPC slice near the mobile edge of ENB to greatly reduce the latency for time-critical applications. The resource allocation methodology of multiple CPU cores for vEPC and LW-EPC slicing is being developed. This paper proposes a simple but powerful algorithm called specifically assigned cores (SAC) to achieve better utilization of CPU cores. Our preliminary results show that SAC outperforms the default scheme, namely randomly assigned cores (RAC), in terms of lower CPU load and less packet loss. The superiority of SAC over RAC amplifies with the traffic level.