User guide

Polycom RMX 1500/2000/4000 Getting Started Guide
A-5
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.
LDAP Lightweight Directory Access Protocol.
Line Rate The amount of bandwidth used by a communication
device, measured in Kbps (kilobits per second).
LPR Lost Packet Recovery. An algorithm that creates
additional packets that contain recovery information
necessary to reconstruct lost packets.
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.
PRI Priority Rate Interface. An ISDN interface designed for
high volume data communication. Consists of 23 B
channels of 64 Kbps each and one D channel of 64 Kbps.
In Europe, the PRI line provides 30 B channels + one D
channel.
PSTN Public Switched Telephone Network.
Abbreviation/
Term
Explanation