Asynchronous Serial Communications Programmer's Reference Manual (32022-90052)

Glossary 329
Glossary
TTUTIL Also known as the
Workstation Configurator. A
program, TTUTIL.PUB.SYS, on
the HP 3000 that is used to create
and modify terminal and printer
type files.
Tymnet A proprietary public
data network in the USA.
typeahead A facility that allows
terminal users to enter data
before a read is actually posted to
the terminal.
U
unacknowledged frame
number (K) The number of
frames that can be transmitted
without receiving an
acknowledgment from the
destination address. When this
number (K) frame is reached, the
same K frames are retransmitted.
unedited mode See
transparent mode.
V
V.24 The CCITT recommendation
that defines the function of the
interchange circuits between a
DTE and a DCE.
validation The process of
ascertainingwhether thenetwork
transport configuration file has
been correctly configured. This is
accomplished by using the
NMMGR Validate Configuration
File screen.
VAN Value Added Network. A
datacommunicationnetwork that
uses and pays for facilities
belonging to another carrier. The
value-added package is then sold
to a user.
VC See virtual circuit.
virtual circuit A logical
association between two
physically separate DTEs.
Virtual Terminal A network
service that allows a user to
establish interactivesessionsona
node.
VPLUS Software used to
generate screens such as those
displayed by NMMGR.
V-Series (V.##) CCITT A set of
CCITT recommendations related
to data communication over a
voice-grade telephone network.
VT See Virtual Terminal.
W
WAN Wide Area Network. A data
communications network of
unlimited size, used for
connecting localities, cities, and
countries.
Workstation Configurator A
utility available on MPE/iX
systems, TTUTIL.PUB.SYS, that
allows users to create customized
terminal and printer types by
entering data through a series of
VPLUS screens.