Summary

Recommendation ITU-T H.450.1 describes the procedures and the signalling protocol between ITU‑T H.323 entities (packet-based multimedia communications systems) for the control of supplementary services. The signalling protocol which is defined within this Recommendation is common to all ITU‑T H.323 supplementary services.

Detailed procedures applicable to individual supplementary services are specified by other Recommendations of the ITU‑T H.450.x-series and by individual manufacturers for proprietary services using the capabilities defined in this Recommendation.

The procedures of this Recommendation are derived from the generic functional protocol specified in ISO/IEC 11582 for private integrated services networks (PISN).

The revision approved in May 2011 corrects errors discovered in the initial publication.