Error Handling for Protocol Data – NAS
Protocol Data Error |
AMF Handling |
---|---|
N1 message is too short to contain a complete message type information element. |
Ignore the message. |
N1 message with message type not defined or not implemented. |
Return a status message with cause #97, message type non-existent or not implemented. |
AMF cannot parse N1 message. It is a request message. |
AMF formulates a reject message and sends it to UE. |
AMF cannot parse N1 message as mandatory IE is missing. It is a response message. |
Stop retransmission timer and treat it as transmission failure. Formulate and send 5GMM status message to UE with cause #96, invalid mandatory information. |
Limit on repetition of information elements is exceeded. |
AMF handles the contents of the information elements appearing first up to the limit of repetitions and ignores all subsequent repetitions of the information element. |
N1 message with optional IEs that have incorrect syntax. |
AMF ignores optional IEs and accepts rest of the message. |
Conditional IE errors. |
For Conditional IE handling, AMF sends MM status message with cause #100 CONDITIONAL_IE_ERROR |