Application of the "Endless train" method for the SDN controller OpenDayLight. Using the cloud for software defined networks opens new possibilities for the organization of computing processes of network controllers. Methods of virtual entities maintenance in a cloud environment allow counting on relatively infinite computing resources of the cloud service called Platform as a Service. Today it is possible to evaluate the degree of utilization of computing resources for the software controller operation only theoretically. The article considers the possibility of using an "endless train" method for virtualization of individual functional opportunities of SDN OpenDayLight controller. This method allows to organize controller computer processes caused by the need to serve the dynamically changing stream of user applications, such as initialization of the flow or the organization of virtual networks. In the section "Architecture and basic features SDN controller" the main components and functionality of the controller OpenDayLight were described. The method of "endless train" for the distribution of tasks between virtual machines and possibility of its use for various functions of the OpenDayLight controller were considered in the section "The method of "endless train" for the organization of the computational process SDN”. In the next section "Description of the experiment" the results of simulation modeling of proposed method to study its effectiveness are presented.