NetIPC 3000/XL Programmer's Reference Manual (5958-8600)

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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 interactivesessionson a
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
Workstation Configurator A
utility available on MPE XL
systems that allows users to
create customized terminal and
printer types by entering data
through a series of VPLUS
screens.
X
X.3 Defines the user facilities
that should be internationally
available from the packet
assembler/disassembler (PAD)
facility when this is offered by a
public data network.
X.21 Defines the physical
interface between a DTE and a
DCE of a public data network
where the access to the network
is made over synchronous digital
lines.
X.25 Defines the interface
between a DTE and a DCE for
packet mode operation on a
Public Data Network (PDN).