A.4 Causes related to invalid messages

24.5013GPPNon-Access-Stratum (NAS) protocol for 5G System (5GS)Release 18Stage 3TS

Cause #95 – Semantically incorrect message

This 5GMM cause is used to report receipt of a message with semantically incorrect contents.

Cause #96 – Invalid mandatory information

This cause 5GMM indicates that the equipment sending this 5GMM cause has received a message with a non-semantical mandatory IE error.

Cause #97 – Message type non-existent or not implemented

This 5GMM cause indicates that the equipment sending this 5GMM cause has received a message with a message type it does not recognize either because this is a message not defined, or defined but not implemented by the equipment sending this 5GMM cause.

Cause #98 – Message type not compatible with protocol state

This 5GMM cause indicates that the equipment sending this 5GMM cause has received a message not compatible with the protocol state.

Cause #99 – Information element non-existent or not implemented

This 5GMM cause indicates that the equipment sending this 5GMM cause has received a message which includes information elements not recognized because the information element identifier is not defined or it is defined but not implemented by the equipment sending the 5GMM cause. However, the information element is not required to be present in the message in order for the equipment sending the 5GMM cause to process the message.

Cause #100 – Conditional IE error

This 5GMM cause indicates that the equipment sending this cause has received a message with conditional IE errors.

Cause #101 – Message not compatible with protocol state

This 5GMM cause indicates that a message has been received which is incompatible with the protocol state.

Cause #111 – Protocol error, unspecified

This 5GMM cause is used to report a protocol error event only when no other 5GMM cause in the protocol error class applies.

Annex B (informative):
Cause values for 5GS session management