PictureTel Concorde 4500 Servicing Manual page 209

integrated services digital network (ISDN)
A network that provides or supports various telecommunications services, which provide
digital connections between the customer and the network interface.
inverse multiplexing
The capability to phase align and synchronize several high-speed network transmissions of
56 or 64 kbps into a single, high-speed videoconferencing stream for PictureTel equipment.
For example, six 64 kbps lines can be used to form the equivalent of a single 384 kbps stream.
ITU-T
International Telecommunications Union, Telecommunications Sector. A group that
establishes standards for telecommunications.
ITU-T H.320
A set of global standards, often referred to as Px64, that covers videoconferencing over ISDN
and switched-56 networks.
ITU -T V.35
A standard that governs data transmission at 48 kbps. In practice, V.35 is used for
synchronous transmission up to 2.048 megabits per second.
ITU -T X.21
A physical interface standard between data terminal equipment and data circuit-terminating
equipment for synchronous V-series modems, which includes an inband dialing capability.
jumper
A patch cable or wire that is used to establish a circuit; generally of a temporary nature; often
a ßexible narrow gauge or stranded wire.
kilobits per second (kbps)
A unit of data transmission rate equal to 1,000 bits per second.
loopback test
A diagnostic test for a speciÞc IMX subsystem. The test loops data back onto that subsystem.
M-8000
A PictureTel multipoint bridge.
megabits per second (Mbps)
A unit of data transmission rate equal to 1,000,000 bits per second.
modem
Modulator/demodulator. A device used to convert digital signals to and from analog.
Glossary-5