A method enables communication between Session Management Function (SMF) and User Plane Function (UPF) instances which are separately deployed behind Network Address Translation (NAT) services. The method includes configuring an SMF or a UPF to initiate an association with a corresponding UPF or SMF. The SMF registers first information with a Network Repository Function (NRF) enabling the remote UPF to communicate with the SMF through a NAT service. The method further includes obtaining second information from the NRF enabling the SMF to communicate with the remote UPF through the NAT service. The method also includes sending an association request to the remote UPF based on the second information and receiving an association response from the remote UPF through the NAT service.