Digicom 3910 Interface, Kbps, Keypad, Leased line, Link, Local analog loopback, Loopback, Modem

Glossary

interface	A shared boundary between functional units.
ITU	International Telecommunications Union. The telecommunications agency of the United Nations,
	established to provide standardized communications procedures and practices. Before
	March 1993 it was called CCITT.
ITU-T	The Telecommunications Standardization Sector of the International Telecommunications Union,
	an advisory committee established by the United Nations to recommend communications
	standards and policies. Before March 1993 it was called CCITT.
JM8	A jack used for leased-line networks. Pins 1 and 2 are the transmit pair and Pins 7 and 8 are the
	receive pair.
kbps	Kilobits per second. One kilobit is usually taken to be 1,024 bits.
keypad	A set of seven keys surrounding the DCP’s LCD. These keys are used to select configuration
	options and to maneuver through the DCP menu.
LCD	Liquid Crystal Display. Thin glass plates containing liquid crystal material. When voltage is
	applied, the amount of light able to pass through the glass plates is altered so that messages
	can be displayed.
leased line	A private line connection exclusively for the user. No dialing is necessary.
LED	Light Emitting Diode. A light or status indicator that glows in response to the presence of a
	certain condition (e.g., an alarm).
link	The physical connection between one location and another used for data transmission.
local analog loopback	A test in which the modem’s transmit voice frequency (VF) signal is looped to its receiver.
long space disconnect	A disconnect effected when the modem receives an extended space from a remote modem.
	When a modem is commanded to disconnect, it transmits a continuous space to the opposite
	modem before disconnecting.
loopback	A diagnostic procedure that sends a test message back to its origination point. Used to test
	various portions of a data link in order to isolate an equipment or data line problem.
menu tree	The structure containing the menu hierarchy starting at a Top-Level menu and extending down to
	various device functions.
mixed inbound rates	In a multipoint network, several different data rates from tributary modems’ transmitters
	communicating with one control modem.
MNP	Microcom Networking Protocol. Levels 2-4 of this protocol, similar to ITU V.42, detect and correct
	data errors caused by telephone line noise and signal distortion. Level 5, similar to ITU V.42bis,
	includes data compression.
modem	MOdulator/DEModulator. A device used to convert data from a digital signal to an analog signal
	so that data can be transmitted over a telephone line. Once the data is received, the analog
	signal is converted back into a digital signal.
modulation	The process of varying some characteristics (usually amplitude, frequency, and/or phase) of a
	carrier wave to form data transmissions.
multiplexer (mux)	A device used to interleave or simultaneously transmit multiple independent data streams into a
	single high-speed data stream. Multiplexing techniques include FDM (frequency division
	multiplexing), TDM (time division multiplexing), and STDM (statistical time division multiplexing).
multipoint line	A circuit connecting one control modem with one or more tributary modems.
network	A configuration of data processing devices used for information exchange.
network management	The customer-assigned diagnostic address of a modem.
address

3910-A2-GN32-40 September 1998 Glossary-5