Hereinafter, example embodiments will be described with reference to the drawings. A configuration example of a communication system according to Example Embodiment 1 is described by using FIG. 1. The communication system in FIG. 1 includes a control device 10, a service control device 20, an application server 30, a base station 40, and a communication terminal 50. The control device 10, the service control device 20, the application server 30, the base station 40, and the communication terminal 50 may be computer devices which a processor operates by executing a program stored in a memory. Moreover, the control device 10 and the service control device 20 may be each referred to as a core network device disposed in a core network.

The application server 30 provides a service to the communication terminal 50. The service may be, for example, an application service, and an IoT service, or the like.

The service control device 20 authenticates the application server 30. Specifically, the service control device 20 may determine whether or not the application server 30 is an application server permitted to provide a service to the communication terminal 50. For example, the service control device 20 may hold list information of an application server permitted to provide a service to the communication terminal 50.