by A.B. Covell  Designing a Videoconferencing Solution Summary of ITU Videoconferencing Standards: H.320 A suite of standards defining videoconferencing interoperability over ISDN. These standards define rules for establishing communications, framing and synchronizing media, and inverse multiplexing ISDN channels. H.320 also includes the following video and audio coding standards: H.261 A video compression standard for bandwidth multiples of 64 Kbps G.711 Basic audio compression at 48 Kbps to 64 Kbps -- low computation pulse code modulation technique same as used in regular telephony G.722 Higher quality audio at the same bandwidths using more sophisticated audio processing G.728 Lower bit rate audio compression -- 16 Kbps H.323 A suite of standards defining interoperability of videoconferencing over packet switched networks with no guaranteed quality of service (QoS). These standards define the packetization and synchronization of media over non-QoS packet networks and a gateway for the interoperability of H.320 and H.323 systems. The following video and audio coding standards are part of H.323: H.261 Same video compression standard also used in H.320 and H.323 H.263 An alternative compression standard for low bit rate communications G.711, G.722, G.728 -- audio compression standards also used in H.320 G.723 Audio compression for 5.3 Kbps and 6.5 Kbps H.324 A suite of standards defining videoconferencing interoperability over POTS that establishes low-bandwidth multiplexing/control protocols. H324 includes the following standards: H.263 Although H.261 is included in the standard, H.263 is commonly used since it can compress video for very low bit rate transmission. G.723 H.324 incorporates only low bit rate audio compression V.80 Standard application interface for developing H.324 systems that convert synchronous data streams to modem asynch, enable rate adjustments during a call, and notify client software of lost packets T.120 A suite of videoconferencing data collaboration standards that is included in the three H.32x standards described above. T.120 includes: T.124 Conference control standard T.126 Standard for sharing still images T.127 Binary file transfer standard Designing a Videoconferencing Solution Typical Videoconferencing Applications Characteristics Of A Successful Videoconference Solution Summary of ITU Videoconferencing Standards Videoconference System Alternatives Network Considerations M ix and Match Sample Scenarios Putting It All Together Videoconferencing Web Resources Print This Page E-mail this URL