Multitech CommPlete MT5634HD8, User Manual, Page: 89 / 99

Glossary
CommPlete Communications Server 83
Serial Port : The connector on a PC used to
attach a serial device (a device that need to
receive data one bit after another), such as a
mouse, printer or modem. It consists of a 9- or 25-
pin connector that sends data in sequence. Serial
ports are referred to as “COMx” ports, where x
is 1 to 4 (COM1 through COM4). A serial port
contains a conversion chip called a UART,
which translates between internal parallel and
external serial formats.
Server : A computer that provides disk space,
printer access, or other shared services, to
computers over a network.
Software : The set of instructions that make
computer hardware perform tasks. Programs,
operating systems, device drivers and
applications are all software.
Spoofing : A command recognized by modems
which have been manufactured specifically for
use within the UNIX UUCP (UNIX to UNIX
Copy) facility. Spoofing is the process of
transparently disabling the “g” protocol used
by UUCP and substituting the modem’s own
error correction protocol for data integrity. The
process “spoofs” the UNIX host into
transmitting data faster than normal, because
the acknowledgments are actually sent by the
modem instead of the remote UNIX computer.
Spooling (Simultaneous Peripheral
Operations On-line)
: Overlapping a low-
speed operation with normal processing, such as
printing a file or document in the background
while creating a new document in the
foreground.
SPX (Sequenced Packet Exchange) : A data
transport protocol developed by Novell used for
interprocess communications. It guarantees that
an entire message arrives intact and uses the
NetWare IPX protocol as its delivery
mechanism.
Switch Line : In communications, a physical
channel established by dynamically connecting
one or more discreet segments. This connection
lasts for the duration of the call after which
each segment may be used as part of a different
channel. Contrast with leased line.
Switched Network :
A network in which a temporary connection is
established from one point via one or more
segments.
Synchronous Transmission : The transmission
of data which involves sending a group of
characters in a packet. This is a common
method of transmission between computers on a
network or between modems. One or more
synchronous characters are transmitted to
confirm clocking before each packet of data is
transmitted. Compare to Asynchronous
Transmission.
T
T1 Transmission : A standard transmission
speed of 1.544M bps that may be used in its full
bandwidth, or as narrower channels called
“fractional T1” carriers.
TCM (Trellis Coded Modulation) : An error
correction method that allows the receiving
modem to tell if a signal element is in error,
based on the value of the preceding signal
elements. Each signal element is assigned a
coded binary value representing the element’s
phase and amplitude.
Terminal : The screen and keyboard device used
in a centralized computing environment for
interactive data entry. Terminals have no
“box”, which is to say they have no file storage
or processing capabilities.
Terminal emulation : Allows a PC to access a
mainframe computer by generating and
accepting data like a “dumb” terminal.
Threshold : A value or condition which, when
reached, triggers an event.
Toggle : Alternate back and forth between two
states.
Tone dialing : One of two methods of dialing a
telephone, usually associated with push button
phones. Compare with pulse dialing.
Transistor : A semiconductor device used to
amplify a signal, or open and close a circuit. In
digital computers, it functions as an electronic
switch.
TSR (Terminate and Stay Resident) : A
software program that remains active and in
memory after its user interface is closed.
Similar to a daemon in UNIX environments.