tokens: ['Figure', '', 'AAA', 'Server', 'initiated', 'Network', 'SliceSpecific', 'Reauthentication', 'and', 'Reauthorization', 'procedure', '', 'The', 'UE', 'is', 'registered', 'in', 'GC', 'via', 'an', 'AMF', 'The', 'AMF', 'ID', 'is', 'stored', 'in', 'the', 'UDM', '', 'The', 'AAAS', 'requests', 'the', 'reauthentication', 'and', 'reauthorization', 'for', 'the', 'Network', 'Slice', 'specified', 'by', 'the', 'SNSSAIENSI', 'in', 'the', 'ReAuth', 'Request', 'message', 'for', 'the', 'UE', 'identified', 'by', 'the', 'GPSI', 'in', 'this', 'message', 'This', 'message', 'is', 'sent', 'to', 'an', 'AAAP', 'if', 'the', 'AAAP', 'is', 'used', 'eg', 'the', 'AAA', 'Server', 'belongs', 'to', 'a', 'third', 'party', 'otherwise', 'it', 'may', 'be', 'sent', 'directly', 'to', 'the', 'NSSAAF', 'If', 'an', 'AAAP', 'is', 'present', 'the', 'AAAP', 'relays', 'the', 'Reauthentication', 'Request', 'to', 'the', 'NSSAAF', '', 'The', 'NSSAAF', 'checks', 'whether', 'the', 'AAAS', 'is', 'authorized', 'to', 'request', 'the', 'reauthentication', 'and', 'reauthorization', 'by', 'checking', 'the', 'local', 'configuration', 'of', 'AAAS', 'address', 'per', 'SNSSAI', 'If', 'successthe', 'NSSAAF', 'requests', 'UDM', 'for', 'the', 'AMF', 'serving', 'the', 'UE', 'using', 'the', 'NudmUECMGet', 'GPSI', 'AMF', 'Registration', 'service', 'operation', 'The', 'UDM', 'provides', 'the', 'NSSAAF', 'with', 'the', 'AMF', 'ID', 'of', 'the', 'AMF', 'serving', 'the', 'UE', '', 'The', 'NSSAAF', 'provides', 'an', 'acknowledgement', 'to', 'the', 'AAA', 'protocol', 'ReAuth', 'Request', 'message', 'If', 'the', 'AMF', 'is', 'not', 'registered', 'in', 'UDM', 'the', 'procedure', 'is', 'stopped', 'here', '', 'If', 'the', 'AMF', 'is', 'registered', 'in', 'UDM', 'the', 'NSSAAF', 'requests', 'the', 'relevant', 'AMF', 'to', 'reauthenticatereauthorize', 'the', 'SNSSAI', 'for', 'the', 'UE', 'using', 'the', 'NnssaafNSSAAReauthenticationNotification', 'service', 'operation', 'The', 'AMF', 'is', 'implicitly', 'subscribed', 'to', 'receive', 'NnssaafNSSAAReauthenticationNotification', 'service', 'operations', 'The', 'NSSAAF', 'may', 'discover', 'the', 'Callback', 'URI', 'for', 'the', 'NnssaafNSSAAReauthenticationNotification', 'service', 'operation', 'exposed', 'by', 'the', 'AMF', 'via', 'the', 'NRF', 'The', 'AMF', 'acknowledges', 'the', 'notification', 'of', 'Reauthentication', 'request', '', 'If', 'the', 'UE', 'is', 'registered', 'with', 'the', 'SNSSAI', 'in', 'the', 'Mapping', 'Of', 'Allowed', 'NSSAI', 'the', 'AMF', 'triggers', 'the', 'NSSAA', 'procedure', 'defined', 'in', 'clause', '', 'for', 'the', 'UE', 'identified', 'by', 'the', 'GPSI', 'and', 'the', 'Network', 'Slice', 'identified', 'by', 'the', 'SNSSAI', 'received', 'from', 'the', 'NSSAAF', 'If', 'the', 'UE', 'is', 'registered', 'but', 'the', 'SNSSAI', 'is', 'not', 'in', 'the', 'Mapping', 'Of', 'Allowed', 'NSSAI', 'the', 'AMF', 'removes', 'any', 'status', 'of', 'the', 'corresponding', 'SNSSAI', 'subject', 'to', 'Network', 'SliceSpecific', 'Authentication', 'and', 'Authorization', 'in', 'the', 'UE', 'context', 'it', 'may', 'have', 'kept', 'so', 'that', 'an', 'NSSAA', 'is', 'executed', 'next', 'time', 'the', 'UE', 'requests', 'to', 'register', 'with', 'the', 'SNSSAI']