Appendix A: Glossary

Abbreviation/

Explanation

Term

 

 

 

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.722

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.

 

 

A-4

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Polycom DOC2066F manual Procedures and describes network maintenance functions