Appendix A: Glossary
A-4
E1 line An 2 Mb digital switched line used in Europe.
Endpoint An endpoint is any conferencing unit or participating/
connected party.
G. 711 ITU-T audio algorithm, 64Kbps, 3.4 kHz.
G. 72 2 ITU-T audio algorithm, 64Kbps, 7 kHz.
G.728 ITU-T audio algorithm, 16Kbps, 3.4 kHz.
Gatekeeper A type of server that performs two main functions: translates
LAN alias addresses of terminals and gateways to IP
addresses and provides bandwidth management.
H.221 ITU-T standard that defines how to multiplex video, audio,
control, and user data into one serial bit stream.
H.230 ITU-T standard that defines simple multipoint control systems
procedures and describes network maintenance functions.
H.231 ITU-T standard that defines a set of MCU functions and
operational requirements.
H.242 ITU-T standard that defines initiation of communications
between systems and capabilities negotiation procedures.
H.243 ITU-T standard that defines initiation of communications
between systems and capabilities negotiation procedures in
multipoint conferences.
H.261 ITU-T standard that defines the Px64 video coding algorithm.
H.263 ITU-T standard that provides improved compression and
quality of video images at a line rate lower than 384 Kbps.
This standard is not supported by all codecs.
H.264* A proprietary Polycom Video compression standard.
H.264 ITU-T standard that provides improved compression and
quality of video images in lower line rate connections and is
part of the Highest Common mechanism in Video Switching
conferences.
Abbreviation/
Term
Explanation