D.8.4 Unknown or unforeseen message type

24.5013GPPNon-Access-Stratum (NAS) protocol for 5G System (5GS)Release 17Stage 3TS

If the UE or the network receives a UPDS message with message type not defined for the UPDS or not implemented by the receiver, it shall ignore the UPDS message.

NOTE: A message type not defined for the UPDS in the given direction is regarded by the receiver as a message type not defined for the UPDS, see 3GPP TS 24.007 [11].

If the UE receives a message not compatible with the UPDS state, the UE shall ignore the UPDS message.

If the network receives a message not compatible with the UPDS state, the network actions are implementation dependent.