A RAN node includes means for receiving a N2 message containing a list of S-NSSAI of the congested network slice from an AMF and means for sending the list of S-NSSAI and a wait timer for each S-NSSAI in the list in first AN signaling message to an UE when receiving, from the UE, second signaling message containing the list of S-NSSAI to establish an AN signaling connection, the S-NSSAI being indicated in the N2 message as congested by the AMF.