Data Communications - Lucent Technologies MERLIN LEGEND Release 7.0 System Planning Manual

MERLIN LEGEND Communications System Release 7.0
System Planning 555-670-112
5

Data Communications

Terminology
Data Terminal Equipment (DTE). Data station equipment—for example, a
PC, host computer, or LAN workstation, from which data is input and/or
output. DTE, which can also be referred to as a data terminal, uses data
communications equipment (DCE) to transmit and receive the digital
signals it requires.
Data Communications Equipment (DCE). Data station equipment that
enables the transmission of data over digital or analog telephone lines and
trunks. DTE requires DCE as follows:
Data Terminal. Data station equipment (for example, a PC, host computer,
LAN workstation, Group IV fax machine, or a group videoconferencing
installation) from which data is input and/or output. A data terminal uses
data communications equipment (DCE) to transmit and receive the digital
signals it requires.
Modem/ISDN Terminal Adapter Pool. A special type of hardware
configuration that combines one or more pairs of DCEs to enable
communication between modems and ISDN terminal adapter data stations.
A pair consists of one modem and one ISDN terminal adapter. Modem/
ISDN terminal adapter pools are set up in one of two ways depending on
the type of data station being used to send data: analog-to-digital or digital-
to-analog. For more information about these pools, see the application
note, MERLIN LEGEND Communications System Modem Pooling .
Data Hunt Group (DHG). A data calling group typically used to distribute
calls to modem/ISDN terminal adapter pools that have more than one pair
of DCEs. For more information about DHGs, see the application note,
MERLIN LEGEND Communications System Modem Pooling .
Video System. Equipment that allows desktop or group
videoconferencing. This equipment connects either directly or through an
ISDN terminal adapter to an MLX jack on the MERLIN LEGEND System. If
the MLX port is programmed as a 2B Data port, the video systems can use
both of the B-channels assigned to the MLX port to provide video. Many
video applications also support data sharing and/or transfer.
— Modem. A type of data communications equipment that converts
the DTE's outgoing digital signals into analog signals for
transmission over regular (analog) telephone company lines.
Another modem at the receiving data station converts the analog
signals back into digital signals for reception by the DTE—for
example, a PC. An analog data station uses a modem as its DCE.
— ISDN Terminal Adapter. A type of data communications equipment
that transmits digital signals over digital telephone company
facilities—for example, PRI. A digital data station uses an ISDN
terminal adapter as its DCE.
NOTE:
If the video system is connected to the MLX jack through an ISDN
terminal adapter, unless the ISDN terminal adapter itself supports 2B
Data communications, it is recommended that the MLX port not be
programmed as a 2B Data port.
Issue 1
April 1999
5-3