Chapter 1. Introduction; T3 Module Overview - ADTRAN T3 User Manual

Chapter 1

T3 MODULE OVERVIEW

The T3 Module and the T3 D/I (Drop and Insert) Module are members of the
ATLAS family of integrated access products providing one or two channelized T3
interfaces. The T3 Module combines with the ATLAS Base Unit and other ATLAS
modules to support requirements calling for delivery of multiple T1 circuits. The
modules terminate all 28 T1s of a channelized T3 into the ATLAS TDM Backplane
for use in dedicated or switched services. The T3 module has a DSX-3 level phys-
ical interface and the T3 D/I module has two T3 interfaces. The T3 D/I module
may terminate between 2 and 28 T1s as the T3 into the ATLAS and pass through
the remaining bandwidth out of the secondary T3 port. The secondary T3 port
may not be used to terminate bandwidth on the ATLAS, but passes the T1s back
out the primary T3 interface. Timing for the ATLAS may be sourced from the T3
module. The timing sources available from within the T3 module are any of its
odd numbered T1s (1-27), the internal 44.736 MHz oscillator (STRATUM 4), or the
T3 receive clock. The T3 module supports dedicated T1 links as well as robbed-bit
switched terminations.
Typical applications calling for ATLAS and the T3 Module include the following:
•
•
Figure 1-1 on page 1-2 shows the T3 bandwidth management application.
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Digital Access Cross Connect System (3/1/0 DACS). Any DS0 on any T1 cir-
cuit delivered on the T3 can be switched to any other DS0 on any other circuit.
T3 Bandwidth Management. A T3 circuit carrying voice, data, video, and other
traffic can have its payload groomed and directed to the appropriate interface
inside the ATLAS system.
T3 Module User Manual
Introduction
1-1