The ITU-T Recommendation for a system for establishing communications between audiovisual terminals using digital channels up to 2 Mbps. H.424 addresses call setup and teardown, in-band signaling and control, and channel management. H.242 is included in the ITU-T H.320 umbrella recommendation for videoconferencing and multimedia communications over narrowband ISDN (N-ISDN). See also H.320.