A notification is made of information in one PDU session establishment procedure to a terminal apparatus, the information being associated with information for identifying one NW slice that is a target of congestion control and the information for identifying another NW slice associated, to prevent a PDU session establishment procedure using information for identifying multiple NW slices at a time. As a method for interpreting the information for identifying the other NW slice associated, two implementation schemes are defined that use explicit notifications from a network and rules configured for the terminal apparatus. In a case that NW slice based congestion control is applied, information for identifying the NW slice to which establishment of a PDU session is allowed is notified as an exception. In a case that the terminal apparatus notified of a DCN ID during the 5GS connection moves to the EPS after application of 5GS congestion control, connection to the DCN ID that provides the same service level as the NW slice of the target of congestion control is also prevented. This provides a communication control method for implementing a management processing such as 5G congestion control initiated by a terminal apparatus or a network.