MT56DSU2 Owner’s Manual
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Glossary
This section defines several of the terms used in this manual. For an overview of DSU basics, refer to
section 1.4 of this manual.
A
ALBO (Automatic Line Build Out) — part of the “equalizer” circuitry used to compensate for various
gauges and alterations of local loops.
Anti-Streaming — an option that prevents a streaming (jammed) DTE from affecting other devices on a
multi-point network.
asynchronous communications — communications between computer devices at irregular intervals. To do
so, the device adds start and stop bits to each character it sends.
B
BERT (bit error rate tester) — the type of testing used to verify the operating parameters of a data
communications line.
bps (bits per second) — unit of measure for data transmission.
C
Central Office (CO) — the telephone company site where switching equipment is located (as opposed to
customer premises).
channel — the digital path on a cable on which data is transmitted. A logical way to look at the path data
travels when sent between
locations.
circuit assurance — an optional conditioning of the CTS signal.
Clear To Send (CTS) — an interface signal that indicates whether the modem or DSU is ready to accept a
data transmission from the DTE.
CO (Central Office) — facility where communications common carriers terminate customer lines and
locate line interconnection equipment.
clocking — a synchronous device circuit that sends signals at a precise frequency corresponding to the bit
rate of that device.
control station — the station on a DDS multipoint circuit that is nearest the host system and transmits data
to each remote station and receives a single serial bit stream from the remote stations via the MJU.
crossover cable — a cable with a conductor that runs the length of the cable, but connects to a different pin
number at each end (connects pins 2103 and 3 to 2 from DTE to DSU/CSU).
CSU (Channel Service Unit) — a device used to terminate a digital circuit (such as DDS or T1) at the
customer site. Used in combination with a “DSU”.