he entire F1 interface instance between the gNB-DU and gNB-CU utilizing a non-UE-associated signaling connection); and UE- associated (F1AP functions that provide these services are associated with a UE-associated signaling connection that is maintained for a specific UE) services [31]. F1AP consists of elementary procedures (EPs), where an EP is defined as the unit of interaction between gNB-CU and gNB-DU over F1. These EPs are defined separately and are used to create complete sequences in a flexible manner. Unless otherwise stated by the restrictions, these EPs may be invoked independent of each other as stand-alone procedures, which can be active in parallel. An EP consists of an initiating message and possibly its response mes- sage. Two types of EPs, referred to as class 1 and class 2, are used, where the former con- sists of elementary procedures with response (success and/or failure) and the latter comprises EPs without response. A gNB-CU UE F1AP ID is allocated to uniquely identify the UE over the F1 interface within a gNB-CU. The gNB-DU stores the received gNB-CU UE F1AP ID for the duration of time that the UE-associated logical F1-connection is valid. A gNB-DU UE F1AP ID is assigned to uniquely identify the UE over the F1 interface within a gNB-DU. When a gNB- CU receives a gNB-DU UE F1AP ID, it stores it for the period of time that the UE- associated logical F1-connection for the UE remains valid. The UE-associated signaling is used when F1AP messages corresponding to a UE utilize the UE-associated logical F1- connection for association of the message to the UE in gNB-DU and gNB-CU. A UE- associated logical F1-connection uses unique identities that are used to identify UE F1AP messages by the gNB-CU and gNB-DU. A UE-associated logical F1-connection may exist before the F1 UE context58 is setup in the gNB-DU. The F1 interface management procedures include reset, error indication, F1 setup, gNB-DU configuration update, and gNB-CU configuration update on the control plane. The F1-C context management pro