Section: 4.3.1.2 NG Control Plane
Content: The NG control plane interface (NG-C) is defined between the NG-RAN node and the AMF. The control plane protocol stack of the NG interface is shown on Figure 4.3.1.2-1. The transport network layer is built on IP transport. For the reliable transport of signalling messages, SCTP is added on top of IP. The application layer signalling protocol is referred to as NGAP (NG Application Protocol). The SCTP layer provides guaranteed delivery of application layer messages. In the transport, IP layer point-to-point transmission is used to deliver the signalling PDUs. Figure 4.3.1.2-1: NG-C Protocol Stack NG-C provides the following functions: - NG interface management; - UE context management; - UE mobility management; - Transport of NAS messages; - Paging; - PDU Session Management; - Configuration Transfer; - Warning Message Transmission. Further details of NG-C can be found in TS 38.410[ NG-RAN; NG general aspects and principles ]  [16].