The Evolved Packet Data Gateway (ePDG) function allows operators to securely deliver mobile packet core services over untrusted, non-3GPP networks, including some Wi-Fi networks to any Wi-Fi enabled device. This application note describes the ePDG function, how it addresses operators’ key considerations for service delivery over untrusted, non-3GPP networks, as well as illustrating how the ePDG function is supported on the industry-leading Nokia 7750 Service Routing Mobile Gateway (SR MG) platform.