“The authentication proxy is used to authenticate and proxy the Ut interface which is used for supplementary services configuration with VoLTE devices as described in IR.92 using XCAP over HTTP between the mobile device and the Telephony Application Server (TAS). This component has been introduced in Proximus VoLTE architecture thanks to the OSC Radiator GBA/BSF Pack.” – Grégory Wille, Manager, Proximus, Belgium

See Radiator GBA/BSF for more about the product features