Container Migration of Core Network Component in Cloud-Native Radio Access Network

Network Function Virtualization (NFV) technology is a key enabler in future mobile networks to achieve efficient Cloud-Radio Access Network (CRAN) platforms. Thanks to NFV, the core network software components can run in a virtualized environment - implemented by virtual machines (VMs) and/or containers - and make use of compute resources in a cost-effective way. Containerization of the application has gained increased popularity due to its smaller footprint when compared to VMs. A key functionality is the ability to live migrate containers along with their supported applications to a distinct server without causing service disruption.In this paper, we study the impact of a checkpoint-based approach for stateful container migration of the core network component SPGW (Serving /PDN Gateway) virtual functions, which handle both the control data with the MME (Mobility Management Entity) and the user data through the GPRS Tunnelling Protocol (GTP) tunnel implemented in the OpenAirInterface (OAI) software. The container states (memory and running processes) are migrated using the Checkpoint and Restore in Userspace (CRIU) package. The study accounts for the CRIU current limitations, provides a solution to overcome said limitations, and evaluates the C-RAN mobile user service downtime caused by the enabled Docker Container migration of SPGW.