Abstract
Software-Defined Network (SDN) is an approach to decoupling the routing decision unit (control plane) from the transfer unit (data plane) which enables the control plane to become directly programmable. The network administrator dynamically controls the whole network without changing their equipment. SDN has become a hot issue in recent years, especially in cloud application services because it has the advantage of being a programmable optimized network regardless of the network conditions. However, while the Internet constantly continues to expand, the existing controller architecture can not afford the instantaneous traffic which results in a network performance degradation. Therefore, in this paper, we designed a loading adaption approach for the controller of a Software-Defined Network. Additionally, we propose a migration protocol, so that when the controller detects excessive traffic it will automatically process loading adaption through the switch migration. In the end, we conducted experiments to evaluate our proposing approach. The results show that our system can perform the load adaption efficiently and rapidly before the controller is overwhelmed, and it will not cause significant overhead to the network.