UE 发起的业务请求流程

sequenceDiagram participant UE participant gNB participant AMF participant SMF participant UPF UE->>gNB: ① NAS: Service Request gNB->>AMF: ② Initial UE Message(Service Request) AMF->>SMF: ③ Nsmf: UpdateSMContext(UP activate) SMF->>UPF: ④ N4 Modification(FAR改为Forward) AMF->>gNB: ⑤ Initial Context Setup Request / PDU Session Resource Setup gNB->>UPF: ⑥ N3隧道建立(GTP-U) gNB-->>AMF: ⑦ Response Note over UE,UPF: CM-CONNECTED恢复，可传输数据