Section: 5.4.2.4 NAS security mode control completion by the network
Content: The AMF shall, upon receipt of the SECURITY MODE COMPLETE message, stop timer T3560. From this time onward the AMF shall integrity protect and encipher all signalling messages with the selected 5GS integrity and ciphering algorithms. If the SECURITY MODE COMPLETE message contains a NAS message container IE with a REGISTRATION REQUEST message, the AMF shall complete the ongoing registration procedure by considering the REGISTRATION REQUEST message contained in the NAS message container IE as the message that triggered the procedure. If the SECURITY MODE COMPLETE message contains a NAS message container IE with a DEREGISTRATION REQUEST message, the AMF shall complete the ongoing deregistration procedure by considering the DEREGISTRATION REQUEST message contained in the NAS message container IE as the message that triggered the procedure. If the SECURITY MODE COMPLETE message contains a NAS message container IE with a REGISTRATION REQUEST message, the 5GMM capability IE included in the REGISTRATION REQUEST message indicates "S1 mode supported" and the AMF supports N26 interface, the AMF shall initiate another NAS security mode control procedure in order to provide the selected EPS NAS security algorithms to the UE as described in subclause 5.4.2.2. This second NAS security mode control procedure should be initiated as part of 5GMM common procedures of the ongoing registration procedure. If the SECURITY MODE COMPLETE message contains a NAS message container IE with a SERVICE REQUEST message, the AMF shall complete the ongoing service request procedure by considering the SERVICE REQUEST message contained in the NAS message container IE as the message that triggered the procedure. If the SECURITY MODE COMPLETE message contains a NAS message container IE with a CONTROL PLANE SERVICE REQUEST message, the AMF shall complete the ongoing service request procedure by considering the CONTROL PLANE SERVICE REQUEST message contained in the NAS message container IE as the message that triggered the procedure.