Glossary - Polycom VIEWSTATION Training Manual

End-User Training Guide: ViewStation
VIDEOCONFERENCING GLOSSARY
Algorithm
– A set of specifications that define methods and procedures for
transmitting audio, video, and data.
Analog Gateway
– A means of connecting dissimilar codecs. Incoming
digital signal from one type of codec is decoded by a similar codec and
converted to analog. The Analog signal is then passed to the dissimilar
codec, coded, and decoded at the far end. Analog gateways achieved
interoperability in a nonstandard environment, but have the disadvantages of
degrading video and audio quality and often reducing functionality.
Annex D Graphics
– An addendum to the H.320 videoconferencing protocol
used for still image transfer between dissimilar videoconferencing systems.
ATM
– Asynchronous Transfer Mode. An emerging networking method that
can be used for carrying voice, video and data simultaneously over low
speed (T1 – 1.5 mbps) or very high speed (622 mbps) networks.
Bandwidth
– Amount of transmission capacity.
For more
information
Basic Rate Interface (BRI)
– An ISDN access or subscriber line,
call
consisting of two 64 kbps B ("bearer") channels and one 16 kbps D channel
408-402-9000
used for both data and signaling purposes.
Broadcast
– One-way video, usually from a single transmitting site to many
receiving sites. In some cases, the receiving sites can communicate to the
transmitting site on an audio-only basis.
Channel Bank
– Used to divide a T1 access facility into 24 digital or analog
circuits.
Channel Service Unit (CSU)
– A type of customer premise equipment that
terminates a T1 access facility to a channel bank, PBX or other equipment
capable of supporting a T1 interface.
Codec
– Coder-Decoder: a device that encodes an incoming analog signal
into a digital signal for transmission to another codec. The digital signal is
decoded into analog format. In videoconferencing, codec typically code and
decode video and audio.
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VSGi - Polycom ViewStation End-user Training Guide