Library items tagged: Videoconferencing

The increased popularity of IP (H.323) based services due mainly to the lower cost of connection has spawned a great deal of development to produce effective methods of delivering high quality videoconference (and telephone traffic) over the IP infrastructure. The Internet Engineering Task Force (IETF) has been particularly active in defining standards in this area while the major network equipment manufacturers have produced workable network solutions.

The main standard in use for data sharing within videoconferencing is T.120 Equipment that is T.120 compliant interleaves the data sharing information within the pass band of the H.320, H.323 etc. conferencing channel. This is an asset as sound, vision and data are shared across a single channel, but it can also be a hindrance as with low bandwidth channels, e.g. ISDN2, the T.120 data exchange part can degrade the audio and video signals to an unacceptable degree. For further information, see the VTAS guide, Data Sharing within Videoconferencing.

Manufacturers may also choose to include proprietary enhancements, e.g. Polycom’s Siren Audio extends the audio bandwidth up to 14kHz to improve the sound quality. These proprietary enhancements are not international standards so only provide a benefit when used between products from the same manufacturer. Proprietary standards should not be confused with ‘options’ within the ITUT standards. The options are not mandatory but when incorporated will allow improved compatible communication between dissimilar equipment without problems.