PictureTel Concorde 4500 Servicing Manual page 211

pulse dialing
A method of dialing on public switched telephone networks that uses a series of audible
pulses to represent individual telephone number digits. Each telephone number digit, 0-9, is
represented by the corresponding number of pulses.
RJ-11
The small, plastic, four-wire plug on a telephone set.
RS-232C
A set of standards that deÞnes the mechanical and electrical characteristics for connecting
DTE and DCE data communications devices. It also deÞnes what the interface does,
describes circuit functions, and connector pin assignments.
RS-366
Generic dialing (ACU) interface. See also ITU-T V.35 and EIA RS-449.
speed-dial number
A multidigit telephone number stored in abbreviated form for easy recall.
switched-56
A switched network interface operating at 56 kbps.
switched network
A series of points interconnected by public, voice-grade telephone lines or digital-grade lines,
with switching facilities or exchanges operated by public telephone companies. See also
dedicated network.
T1
An AT&T term for a digital carrier facility used to transmit a DS1 formatted digital signal at
1.544 megabits per second (United States and Japan).
unavailable seconds (UAS)
A measure of performance on a network access line. This measure indicates the number of
seconds a line was unavailable for a 15 minute duration.
videoconferencing
Two-way, full-motion, full-color electronic communication that permits two or more persons
or groups of people in different locations to engage in face-to-face audio and visual
communication.
Y/C
In Y/C video, the Y or luminance signal is separate from the C or hue and color saturation
signal. The luminance is recorded at a higher frequency and therefore more resolution lines
are available.
Glossary-7