Badge-holders have demonstrated a solid understanding of VoLTE (iaw IR.92). They can discuss EPS bearer services used in support of VoLTE, as well as the performance of AMR, AMRWB and EVS voice coders. They understand how to assess packet sizes (including ROHC overheads) for codec modes in the network and on the air interface; and they understand the role & operation, including message flows, of SIP / SDP in support of IMS Registration and VoLTE Session Management, as well as the role of MMTEL.