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Polycom RMX 2000 User Manual

Page 82

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Appendix A-Glossary

A-4

IP

Internet Protocol. The working protocol that forms the
basis of the internet.

ISDN

Integrated Services Digital Network. A set of protocol and
interface standards (voice, video and data) that comprise
a telephone network. There are two types of ISDN lines:
BRI and PRI.

ITU-T Standard

International Telecommunications Union,
Telecommunication Standardization Sector (formerly
CCITT). An international group that produces official
standards for telecommunications.

LAN

Local Area Network. A group of computers and other
devices linked via a network’s operating system.

Line Rate

The amount of bandwidth used by a communication
device, measured in Kbps (kilobits per second).

LDAP

Lightweight Directory Access Protocol.

MCU

Multipoint Control Unit. Device which allows more than
two sites to be connected in a video conference.

Null modem cable

A serial cable designed to eliminate the need for
communication equipment when two digital devices are
directly connected to each other.

Participant

A person using an endpoint to connect to a conference.
When using a Room System, several participants use a
single endpoint.

QCIF

Quarter CIF. A video format with image size of 176x144
pixels that transmits 9.115 Mbps at 30 frames per second
(a quarter of the capacity of CIF). For more information,
see CIF.

QoS

Quality of Service. QoS defines the performance of a
network service, such as the average delay between
packets.

RS-232

A standard for serial interface connection.

Abbreviation/
Term

Explanation