Systems and networks include several inputs and outputs from which they are accessed. Access controls exist to manage authentication and access controls through those inputs and outputs. One of the significant problems in this scope is the difficulty to have a global consistent system or network level access control. Such global centralised access control is needed to make sure that access control decisions taken by different applications at different levels are consistent. In this paper, we propose an SDN-based access control to approach this problem. Different access control methods are proposed to handle user and flow level access information. Access tables in those methods are initiated by network administrators. Concrete rules in those access tables can change dynamically based on network activities. We believe that ultimately all access control systems are going to converge in this direction.