Lucent Technologies DDM-2000 OC-3, User & Service Manual

Page: 290 / 2536

363-206-285
Circuit Pack Descriptions
7-12 Issue 3 June 2001
General Description of Operation 7
The BBG9 OHCTL circuit pack provides the following basic functions:
■
Overhead communications channels
■
X.25 message-based OS interface
■
IntrAOffice Local Area Network (IAO LAN) interface
■
Basic order wire interface.
Detailed Description of Operation 7
OC-3 Transport Overhead Channel 7
Figure 7-5 provides an overall block diagram of the BBG9 OHCTL circuit pack.
The OHCTL terminates an overhead channel from each main and function unit
slot. The overhead channel includes a 192 kb per section DCC (SONET bytes
D1-D3) and a 64-kb/s order wire channel (SONET byte E1).
User Definable Miscellaneous Discrete Environmental Alarms and Controls 7
The system provides four miscellaneous discrete control outputs and 21
miscellaneous discrete alarm/status inputs when the DDM-2000 OC-3 is
configured as a RT. For this application, the SYSCTL supplies all of the necessary
miscellaneous discrete I/O. Alarms are reported via CIT or TL1/X.25. Controls are
also via the CIT or TL1/X.25.
X.25 Message-Based OS Interface 7
The BBG9 OHCTL provides the TL1/X.25 interface to OSs such as Telcordia
Network Monitoring and Analysis (NMA).