If uplink data together with an RRC resume request message is received from a radio terminal in an RRC_INACTIVE state and a radio terminal context is not available in a first RAN node (1), the first RAN node (1) sends a second type of control message to a second RAN node (2). The second type of control message requests the radio terminal context, and is distinct from a first type of control message that is sent to the second RAN node (2) by the first RAN node (1) when an RRC resume request message not accompanied by uplink data is received. This can contribute, for example, to enabling uplink (UL) data of a radio terminal in RRC_INACTIVE to be transmitted to a core network without relocating a radio terminal context from an old RAN node to a new RAN node.