2500-Series Data Service Unit (Dsu); Physical Description; Features - AT&T Callmaster Series Reference Manual

2500-Series Data Service Unit (DSU)

The 2500-Series DSUs allow the user's computer or Data Terminal Equipment (DTE) to com-
municate with remotely located equipment using Digital Data Service network lines. The DSU
integrates all Channel Service Unit (CSU) and DSU functions into one unit and connects between
the network interface and the user's DTE.
The DSU can operate as a point-to-point Local Area Data Set (LADS). It is used when the DCIU
and external processor are more than 400 feet apart. Two DSUs per external processor are
required.

Physical Description

Stand-alone Dimensions (approximate)
Width = 5-3/4 inches
Depth (front to back) = 9-5/8 inches
Height = 2 inches
Multiple Mounting Dimensions (approximate)
Width = 23 inches
Depth (front to back) = 20 inches
Height = 7 inches

Features

Full-duplex
Synchronous operation
Asynchronous operations with certain limitations when used as a LAD
Three color test and status LCD panel
Multi test functions
Two color test and Status/Fault indicator
User selectable options
Mounting
The 2500-Series DSU can be stand-alone or multiple mounted. The stand-alone units
can be wall or desk mounted. The multiple mounted units are mounted in a multiple-
mount housing that can house up to eight DSUs.
Operating Speeds
The 2556A, 2556B, and 2556C operate at 56 kbps. The 2596A, 2596B, and 2596C have
2500-Series Data Service Unit (DSU)
5-93