A combined User Plane (UP) node optimizes the UP data stream handling for 4G/5G network operation as follows. The combined UP node, which includes an access data plane node, an intermediate data plane node, an anchor data plane node, and a session handling process module. If the IP addresses or the namespaces of the access data plane node, the intermediate data plane node, and the anchor data plane node are different, then the downlink and uplink packet stream handling utilizes an intermediate interface path within the combined UP node. If the IP addresses or the namespaces of the access data plane node, the intermediate data plane node, and the anchor data plane node are same, then the downlink and uplink packet stream handling does not utilize an intermediate interface path within the combined UP node, but TEID of the unutilized intermediate interface path is used in PFCP response message.