A method to operate a Network Function, Repository Function, NRF, to manage NF profiles of Session Management Functions (SMFs) in a communication system is provided that is configured to communicate with other network functions of the communications system through a network interface. The NRF receives NF profiles for the SMFs, wherein at least some of the NF profiles each include both a SMF identifier and a service area information for a respective one of the SMFs. After receiving the NF profiles, the NRF stores the SMF identifiers and the service area information of the NF profiles in a repository in memory. The NRF may also receive a NF discovery request for discovering SMFs. After receiving the NF discovery request, the NRF may retrieve from the repository at least one of the NF profiles respectively for at least one SMF based on content of the NF discovery request. The NRF communicates a NF discovery response containing the SMF identifier and the service area information of the at least one SMF.