Glossary

H.239 is an ITU-T recommendationfor role management and additional media channels for H.3xx-series terminals. Sets forth a way to have multiple video channels (e.g., one for conferencing, another for presentation) within a single session (call). H.239 is widely used by H.323 video conferencing systems to support dual video mechanisms, where ...

H.245 is an ITU-T standard that defines a control protocol for multimedia communication.H.245 passes its control information messages over a reliable channel between two entities that are engaged in a multimedia call (voice only or voice and video). H.245 messages are defined using ASN.1 and are encoded using PER.H.245 starts ...

H.264 (also known as MPEG-4 AVC) is currently the de-facto leading standard for video compression. It was standardized in 2003 in a joint effort by the ITU-T Video Coding Experts Group (VCEG) and the ISO/IEC Moving Picture Experts Group (MPEG), known as the Joint Video Team (JVT).H.264 is used in ...

H.281 is an ITU-T recommendation describing how a far end camera control system for H.320 terminals can be operated.H.281 has been adopted for the use of H.323 as well as part of the definition of H.323 Annex Q.

H.323 is an “umbrella” Recommendation by ITU-T , defining protocols that support multimedia communication sessions over packet networks. H.323 provides means for call signaling and control, media transport and control and bandwidth control for both peer-to-peer and multi-party sessions. H.323 was published in November 1996, focusing mainly on video conferencing ...

H.323 Annex Q defines how far end camera control is acheived in the H.323 standard.

H.324 is a circuit switched video telephony protocol specification defined by the ITU and adopted by the 3GPP for mobile video telephony. To learn more about it, see 3G-324M.  

Annex K is a call acceleration technique in 3G-324M. It is also known as MONA (Media Oriented Negotiation Acceleration).It is a set of 3 different techniques for call acceleration which are designed to reduce call setup times to below 1 second.Annex K is designed as a set of 3 classes, ...

HD Voice refers to the use of wideband audio codecs, where the sound spectrum is at least twice or more than that of PSTN.It is quite commont to refer to speech codecs that provide at least 7KHz in sound spectrum as HD Voice.Wideband codecs that are commonly used for HD ...