 if needed for the QoS flow(s) associated with the QoS rule(s), QoS rule operation, and QoS flow level QoS parameters operation, Session - AMBR)). Step 6: The AMF acknowledges the request with 200 OK and responds with a cause: N1_N2_ TRANSFER_INITIATED. Step 7: The AMF sends N2 PDU session request N2 SM information received from the SMF, NAS message PDU Session ID, and NI SM container (PDU session modification command). Step 8: Access Network Specific Resource modification process takes place and the gNB notifies to UE about any change in parameters and UE acknowledges the same. Step 9: An N2 PDU Session Acknowledgment message is sent from the gNB to the AMF with confirmation that the radio-related modifications in Step 8 is successful. VoNR call flow The following are some snapshots from actual traces: PCF->SMF [3] Policy Control Update Notify HyperText Transfer Protocol 2 Stream: DATA, Stream ID: 1, Length 378 JavaScript Object Notation: application/json Object Member Key: resourceUri Member Key: smPolicyDecision Object Member Key: pccRules Object Member Key: 112_SIP_VONR_AUDIO Null value Key: 112_SIP_NR_AUDIO Member Key: _1_1_1_SIP_VNR_AUDIO Null value Key: _1_1_1_SIP_VONR_AUDIO Key: pccRules Member Key: revalidationTime String value: 2020-06-04T22:37:07.482Z Key: revalidationTime Member Key: policyCtrlReqTriggers Array String value: RE_TIMEOUT Key: policyCtrlReqTriggers Key: smPolicyDecision Figure 7.26 - Packet capture PCF to SMF policy control update notify The following figure shows the N1N2 message transfer packet capture during the establishment of a voice call. The key information elements are shown in the diagram: Packet Core Procedures SMF->AMF [5] N1N2 Transfer Message HyperText Transfer Protocol 2 Stream: DATA, Stream ID: 5, Length 710 MIME Multipart Media Encapsulation, Type: multipart/related, Boundary: "boundary" [Type: multipart/related] First boundary: --boundary\r\n Encapsulated multipart part: (application/json) Content-Id: root\r\n Content-Type: application/json\r\n\r\n JavaScript Object Not