established to provide standardized
communication procedures and practices,
including frequency allocation and radio
regulations worldwide. (Formerly CCITT).
Internet Protocol (IP). In TCP/IP, a protocol that
routes data from its source to its destination in an
Internet environment.
LIC unit (LIU). A line interface coupler unit (LIU)
consisting of:
One power supply (PS) associated with
Two line interface bases (LIBs), housing
Multiplex cards, and
Line interface coupler cards (LICs)
line adapter (LA). The part of the TSS, HPTSS,
or TRSS that scans and controls the transmission
lines. Also called scanner.
For the ESS the line adapters are Ethernet LAN
adapters (ELAs).
For the TSS the line adapters are low-speed
scanners (LSSs).
For the HPTSS the line adapters are high-speed
scanners (HSSs).
For the TRSS the line adapters are token-ring
adapters (TRAs).
line interface base (LIB). A board which
houses:
One multiplexer
Up to eight LICs
line interface coupler (LIC). A circuit that
attaches up to four transmission cables to the
controller (from DTEs, DCEs or telecommunication
lines).
local area network (LAN). A computer network
located on a user's premises within a limited
geographical area. Communication within a LAN
is not subject to external regulation; however,
communication across the LAN boundary may be
subject to some form of regulation.
logical unit (LU). (1) In SNA, a port through
which an end user accesses the SNA network in
order to communicate with another end user and
through which the end user accesses the
functions provided by system services control
points (SSCPs). An LU can support at least two
sessions, one with an SSCP and one with another
LU, and may be capable of supporting many
sessions with other logical units. (2) A type of
network addressable unit that enables end users
to communicate with each other and gain access
to network resources.
low-speed scanner. Line adapter for lines up to
256 kbps. It is composed of as communication
scanner processor (CSP) and a front-end
low-speed scanner (FESL).
maintenance and operator subsystem
(MOSS). The part of the 3745 that provides
operating and servicing facilities to the user and
IBM service representative.
maintenance and operator subsystem
extended (MOSS-E). The licensed internal code
loaded on the service processor fixed disk to
provide maintenance and operator facilities to the
user and IBM service representative.
microcode. A program that is loaded in a
processor (for example, the MOSS processor) to
replace a hardware function. The microcode is
not accessible to the customer.
modem (modulator-demodulator). See DCE.
multipoint connection. A connection
established among more than two data stations for
data transmission. The connection may include
switching facilities.
multistation access unit (MAU). In the IBM
token-ring network, a wiring concentrator that
connect up to eight lobes to a ring.
native mode. An IBM modulation scheme.
NetView Performance Monitor (NPM). An IBM
licensed program that collects, monitors, analyses,
and displays data relevant to the performance of a
VTAM telecommunication network. It runs as an
on-line VTAM application program.
Network Control Program (NCP). An IBM
licensed program that provides communication
controller support for single-domain, multiple
domain, and interconnected network capability.
nonswitched line. A connection between
systems or devices that does not have to be made
by dialing. The connection can be point-to-point
X-5
Glossary