363-206-305
Circuit Pack Descriptions
 Issue 3 June 2000
7-49
Figure 7-20. BBG19 DS3 Circuit Pack Block Diagram 
Control Circuitry 
7
The BBG19 DS3 circuit pack interfaces with the SYSCTL via the intra-shelf control 
bus. The BBG19 DS3 provides maintenance elements for reporting the status of 
the circuit pack, status of the incoming STS-1 and DS3 signals, as well as the 
circuit pack inventory information (
CLEI
 code, date of manufacture, etc.). These 
maintenance elements are used by the SYSCTL for fault detection and isolation. 
Conversely, the BBG19 DS3 responds to control signals from the SYSCTL (such 
as active and fault LED controls). 
Locked DS3 Circuitry 
7
The DDM-2000 OC-3 accepts two BBG19s installed side-by-side in a dual 0x1 
configuration. This configuration allows for efficient bandwidth utilization in the 
network for data services traffic. Each DS3 is assigned to both rotations of the ring 
DS3
Receiver
Multiplexer
Demultiplexer
DS3
Driver
LBO
Intrashelf
STS-1
To/From
OLIU CPs
From
From
Shelf
-48V Fuses
SYSCTL
-48V A
-48V B
Timing
Control
To/From
Loopback
To/From
DS3
TGS CPs
(Service &
Protection)
tpa 852245/01
Data Services
Device