363-206-305
Maintenance Description
9-6  
Issue 3 June 2000
Operations System (OS) Interface 
(Operations Tier 3) 
9
The third operations tier consists of the remote OS interfaces. These OS 
interfaces include miscellaneous discrete telemetry and a TL1/X.25 interface. 
Miscellaneous Discretes 
9
To allow monitoring and control of equipment collocated with a DDM-2000 
FiberReach Multiplexer in a remote site, a set of user-definable miscellaneous 
discrete environmental alarms and controls is provided.
Twenty-one miscellaneous discrete alarm/status points are provided to monitor 
environmental conditions at remote terminal sites (open door, high temperature, 
etc.).  The first 14 points and points 16 through 21 are activated by contact 
closures.  The fifteenth point (External Minor) is for monitoring of remote structure 
power and fan apparatus (for example, DC power shelf failure); this point is 
activated by a -48 volt input.
Four control points are provided to control equipment (pumps, generators, etc.) at 
remote terminal sites.  When activated, the control points provide a contact 
closure between the control point output and ground.
Miscellaneous discrete alarms/statuses and controls are transmitted between the 
remote DDM-2000 FiberReach Multiplexers and the DDM-2000 OC-3 Multiplexer 
host via the SONET section DCC. OS access to all miscellaneous discretes 
alarm/status points (1 through 21) is provided via TL1/X.25. Access to all 
miscellaneous discrete alarm/status points is also provided through the CIT. The 
state of the control points can be reported but not controlled through the CIT.
TL1/X.25 
9
NOTE:
The FiberReach wideband shelf does not provide a direct X.25 interface.  
Access to the X.25 port on a gateway NE is via the DCC.
DDM-2000’s TL1 message-based OS interface provides more detailed reporting 
and control capabilities than the parallel and serial telemetry interfaces. The 
interface uses the standard X.25 protocol and needs no mediation device; that is, 
the interface can be connected directly to an X.25 network. The virtual channels in 
the X.25 link can be used to provide remote access between users and 
DDM-2000 via a packet data network. The remote user could be an OS or a user 
at a terminal. Lucent Technologies is involved in an active OSMINE process to 
ensure compatibility of DDM-2000 FiberReach Multiplexers with Telcordia 
Technologies OSs. The DDM-2000 supports TL1 alarm surveillance and