Methods and/or systems for managing continuity of data flow in 5G networks. A UE may receive a message from a 5G network in response to a PDU session establishment request. The message indicates a failure to establish a PDU session with a first DNN and a first network slice. A PDU session may be established with at least one of a second DNN and a second network slice, if the PDU session is matching with a route selection descriptor applicable to data traffic to be routed through the PDU session. A non-CIoT device may receive a message from a 5G network in response to a service request. The message may indicate failure of a service request procedure, pertaining to a PDU session, such as due to insufficient user-plane resources. The PDU session may be closed and reestablished. If there is lower layer failure in 5G, a connection may be established with a 4G network for data transfer.