Modeling of OpenFlow-related handover messages in mobile networks

Software defined networking (SDN) and its most popular southbound implementation OpenFlow (OF) are already greatly exploited in the existing mobile cellular networks as part of data centers and mobile core networks. Due to user’s mobility, it is of upmost importance for the operators to provide the shortest possible interruption when the mobile users are performing the procedure of handover. In this work, we proposed a novel analytical approach to model the OF-related handover messages exchanged between the OF-switches and the SDN controller. We modeled two different OF-switch implementations and we compared the results: (1) single shared buffer used for the control and data plane; (2) two priority buffers, where the data plane packets are served only when there are no packets to be processed in the control plane. We numerically evaluated the two systems and we validated the model by using simulations. The obtained results clearly point that although the priority buffering increased the complexity, it effectively provided the shortest handover delay. Therefore, the priority buffering should be the preferred mechanism for mobile networks.