Supplement 12 to ITU-T H-series Recommendations provides complementary information on the handling of priority traffic (e.g., international emergency preference scheme (IEPS)/emergency telecommunications service (ETS) traffic) by the ITU-T H.248 entities: Media Gateway Controller (MGC) and Media Gateway (MG).

This supplement illustrates the difficulty, even impossibility, of a generic specification i.e., a generic ITU-T H.248 profile, in justifying concrete, dedicated protocol solutions in the case of an available alternative for "emulation approaches".