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

330 Glossary
Glossary
X
X.3 The protocol that defines
which user facilities should be
internationally available from a
packet assembler/disassembler
(PAD) when this is offered by a
public data network.
X.21 The protocol that 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 The protocol that defines the
interface between a DTE and a
DCE for packet mode operation
on a Public Data Network (PDN).
X.25 address The X.25 address
provided by the network
administration if you are
connected to a public data
network (PDN).
X.25 address key An X.25
address key is a label that maps a
node’s IP address to its X.25
address and its associated X.25
parameters. You have a combined
maximum of 1024 X.25 address
keys in the SVC and PVC path
tables.
X.25 LUG address X.25 address
of a node belonging to a LUG.
X.25 iX System Access The
software that works in
conjunction with the DTC/X.25
Network Access software to
provide MPE/iX access to X.25.
The software resides on an
HP 3000 host and is configured
through use of NMMGR. To
configure access to an X.25
network, you must configure two
software components: the X.25 iX
System Access and the DTC/X.25
Network Access (residing on the
Datacommunications and
Terminal Controller and
configured at the OpenView
Windows Workstation). Together,
these two components provide a
network connection on HP 3000
systems to private and public
X.25 packet switched networks
(PSNs).
X.29 The protocol that defines the
interface for data exchange
between a packet mode DTE and
a remote Packet
Assembly/Disassembly (PAD)
facility over a packet-switching
network.
XON/XOFF protocol The flow
control used by MPE/iX systems
to protect against data overruns.
XON/XOFF protocol is controlled
by the data recipient who sends
an XOFF character (ASCII DC3)
to the sender if it is unable to
continue to receive data. The
sender suspends transmission
until it receives an XON
character (ASCII DC1).
X.Series (X.##) CCITT
recommendations A set of
recommendations for data
communication networks
governing their services,
facilities, andterminalequipment
operation and interfaces.