A method performed by a distributed unit, DU, of a base station, comprising: receiving, from a user equipment, UE, a radio resource control, RRC, message comprising a resume request wherein the RRC message indicates a transition to an RRC connected state from an RRC inactive state; determining (1810, 1830, 1850) whether the resume request of the UE is acceptable or not according to a status of layers managed by the DU; in case that the resume request of the UE is acceptable (1810, 1830) in the DU: transmitting, to a central unit, CU, an initial uplink, UL, RRC message transfer message including an RRC container including the RRC message, the initial UL RRC message transfer message further including an information element to indicate that the resume request of the UE is acceptable in the DU, transmitting, to the CU, a UE context setup response message including resource allocation information for a data radio bearer, DRB, in response to receiving, from the CU, a UE context setup request message for the DRB, and transmitting, to the UE, an RRC connection resume message based on a downlink, DL, RRC message transfer message, in response to receiving, from the CU, the DL RRC message transfer message including the RRC connection resume message based on success of a UE context retrieval by the CU; transmitting, to the UE, an RRC connection setup request message based on a DL RRC message transfer message, in response to receiving, from the CU, the DL RRC message transfer message including the RRC connection setup request message based on failure of a UE context retrieval by the CU; and in case that the resume request of the UE is not acceptable in the DU: transmitting, to the CU, an initial UL RRC message transfer message including an RRC container including the RRC message, the initial UL RRC message transfer message not including the information element, and transmitting, to the UE, an RRC connection reject message based on a DL RRC message transfer message, in response to receiving, from the CU, the DL RRC message transfer message including an RRC connection reject message for the resume request. receiving, from a user equipment, UE, a radio resource control, RRC, message comprising a resume request wherein the RRC message indicates a transition to an RRC connected state from an RRC inactive state; determining (1810, 1830, 1850) whether the resume request of the UE is acceptable or not according to a status of layers managed by the DU; in case that the resume request of the UE is acceptable (1810, 1830) in the DU: transmitting, to a central unit, CU, an initial uplink, UL, RRC message transfer message including an RRC container including the RRC message, the initial UL RRC message transfer message further including an information element to indicate that the resume request of the UE is acceptable in the DU, transmitting, to the CU, a UE context setup response message including resource allocation information for a data radio bearer, DRB, in response to receiving, from the CU, a UE context setup request message for the DRB, and transmitting, to the UE, an RRC connection resume message based on a downlink, DL, RRC message transfer message, in response to receiving, from the CU, the DL RRC message transfer message including the RRC connection resume message based on success of a UE context retrieval by the CU; transmitting, to the UE, an RRC connection setup request message based on a DL RRC message transfer message, in response to receiving, from the CU, the DL RRC message transfer message including the RRC connection setup request message based on failure of a UE context retrieval by the CU; and transmitting, to a central unit, CU, an initial uplink, UL, RRC message transfer message including an RRC container including the RRC message, the initial UL RRC message transfer message further including an information element to indicate that the resume request of the UE is acceptable in the DU, transmitting, to the CU, a UE context setup response message including resource allocation information for a data radio bearer, DRB, in response to receiving, from the CU, a UE context setup request message for the DRB, and transmitting, to the UE, an RRC connection resume message based on a downlink, DL, RRC message transfer message, in response to receiving, from the CU, the DL RRC message transfer message including the RRC connection resume message based on success of a UE context retrieval by the CU; transmitting, to the UE, an RRC connection setup request message based on a DL RRC message transfer message, in response to receiving, from the CU, the DL RRC message transfer message including the RRC connection setup request message based on failure of a UE context retrieval by the CU; and in case that the resume request of the UE is not acceptable in the DU: transmitting, to the CU, an initial UL RRC message transfer message including an RRC container including the RRC message, the initial UL RRC message transfer message not including the information element, and transmitting, to the UE, an RRC connection reject message based on a DL RRC message transfer message, in response to receiving, from the CU, the DL RRC message transfer message including an RRC connection reject message for the resume request.