Rptu Interface Unit; Rptu Overview; Csu Requirements - Toshiba STRATA DK14 Installation And Maintenance Manual

RPTU Interface Unit

System:
DK40i, DK424 or DK424i Release 4.3
Circuits per PCB:
24 channels
Interfaces with:
ISDN PRI
Older Version(s):
none
The DK40i, DK424 or DK424i Release 4.3 systems supports the RPTU according to the common
control units resident in the system.
The RPTU requires installation of a customer-provided CSU in most locations of the U.S. Refer to
"CSU Requirements" on Page 16-5
Testing procedures (local and remote loop back) are in
The RPTU's LEDs indicate a continuous status of its operation. They are shown in
Table 16-8 on Page 16-10
Switches, jumpers, and interface connectors are described in

RPTU Overview

The RPTU is a DS-1 divided into 24 TDM channels using standard T1 electrical signal format.
The RPTU's D-channel is typically the 24th channel and can control the signaling of 23 of its own
B-channels and 24 B-channels of another designated RPTU. Each RPTU can also use its own
D-channel for control.
The DK424 or DK424i, RCTUA provides 8 or 16 channels and DK40i provides 8 or 12 channels.
The 24th channel is still available for D-channel control for both systems.
The RPTU's in-service bit rate is 1.544 mbps (± 4.6 ppm), but during a maintenance session, the
rate may vary ± 32 ppm. The RPTU provides Binary 8-Zero Substitution (B8ZS) and ESF with
Framing Pattern Sequence (FPS) and Cyclical Redundancy Check (CRC) error checking in the
framing bits.
The Embedded Operations Channel (EOC) which carries alarm notifications, statistics,
Note
and error indications is not available with DK Release 4.0 software.
Extracting the Stratum-1 clock from the ISDN PRI, BRI, or T1 provider is the most common
method used to synchronize the RPTU PCB and the DK time switch to the public telephone
network. One RPTU, RBSU, RBUU, or RDTU T1 must extract the clock from the ISDN or T1
provider. The selected unit is designated as the "Primary" timing source in system Program *41-1.
In remote cabinet applications, the Primary clock source PCB must be installed in the Base
Cabinet (main location). For more information, refer to
16-39.
A dealer-supplied CSU must be installed between the ISDN PRI network line and the RPTU PCB
as shown in Figure
Interface Unit (NIU).

CSU Requirements

In the U.S., the CSU must be UL listed and comply with Part 68 of the FCC rules. It must also
comply with the limits for a Class A digital device, pursuant to Part 15 of FCC Rules. In Canada,
the CSU must be CSA certified.
Strata DK I&M 6/00
for CSU installation.
lists the functions for each LED.
16-1. Some telephone companies supply the CSU and call it the Network
"RPTU Loop-back Test" on Page
Figure 16-1.
"Timing and Synchronization" on Page
ISDN Interfaces
RPTU Interface Unit
16-38.
Figure 16-3.
16-5