PDU 会话释放流程

sequenceDiagram participant UE participant AMF participant SMF participant UPF participant gNB UE->>AMF: ① NAS: PDU Session Release Request AMF->>SMF: ② UpdateSMContext(Release) SMF->>UPF: ③ N4: Session Deletion Request UPF-->>SMF: ④ Session Deletion Response(URR报告) SMF->>AMF: ⑤ N1N2MessageTransfer(Release Command) AMF->>gNB: ⑥ PDU Session Resource Release Command gNB-->>AMF: ⑦ PDU Session Resource Release Response AMF-->>UE: NAS: PDU Session Release Command UE-->>AMF: NAS: PDU Session Release Complete SMF->>SMF: 释放IP地址，通知PCF/CHF