Call Flows This section describes the key call flows of compliance to 3GPP specifications. UE RegistrationPDU Session Establishment Call FlowPDU Session ModificationPDU Session ReleaseUE-Initiated Deregistration Call FlowUDM-Initiated Deregistration Call FlowAMF-Initiated Deregistration Call FlowUE Identity Procedure for Authentication Failure Call FlowUE Identity Procedure for Unknown Subscribers Call Flow