Chapter 1. Introduction; Product Overview - ADTRAN DSU III AR User Manual

Introduction
Chapter 1

PRODUCT OVERVIEW

The ADTRAN DSU III AR provides a reliable, high speed data
connection for customer Data Terminal Equipment (DTE) through
Digital Data Service (DDS) lines, DDS secondary channel services
(DDSII), or 4-wire Switched 56 network (SW56) lines.
The DSU III AR supports both synchronous and asynchronous data
communication over the DDS or 4-wire Switched 56 networks.
This unit is an all rate DSU/CSU, supporting services from 2.4 to 64
kbps including 19.2 and 38.4 kbps services. The DSU III AR may be
used in either point-to-point or multi-point circuits.
The DSU III AR provides both V.35 and EIA-232 electrical and
physical DTE interfaces to accommodate a variety of applications.
A second EIA-232 interface is provided for use on DDS lines with
secondary channel services.
To ensure a reliable connection, the unit features an extended
receiver capability which permits operation over long loops (3.4
miles or 5.5 km of 26 AWG at 56 kbps).
In addition to DDS, the unit supports Switched 56 (4-wire) service
with dialing accomplished from the front panel. This model is
compatible with AT&T Accunet and Sprint SW56 type services.
Figure 1-1 on page 1-2 shows a sample point-to-point application
for the DSU III AR.
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