Loop Maintenance Operations System
Encyclopedia
The Loop Maintenance Operations System (LMOS) is a telephone company trouble ticketing system that plays an essential part in the act of repairing local loop
s (telephone lines). When a problem is reported to the Centralized Repair Service Answering Bureau (CRSAB) by a subscriber dialing the designated number (often (1)+611) it is filed and relayed through the Cross Front End, which is a link from the CRSAB to the LMOS network. The trouble report is then sent to the Front End via the Datakit
network, where a Basic Output Report is requested (usually by a lineman working with). BORs consist of line information including past trouble history and MLT (Mechanized Loop Testing) tests. As LMOS is responsible for trouble reports, analysis, and similar related functions, MLT does the actual testing of customer loops. MLT hardware is located in the Repair Service Bureau. Test trunks connect MLT hardware to the telephone exchange
s or Wire Centers, which in turn connect with the subscriber loops.
The LMOS database is a proprietary file system, designed with 11 access methods (variable index, index, hash tree, trie, fixed partition file, etc.). This is highly tuned for the various pieces of data used by LMOS.
LMOS, which was first brought on line as a mainframe application in the 1970s, was one of the first telephone company operations support systems to be ported to the UNIX
operating system. The first port of LMOS was to Digital Equipment Corporation
's PDP 11/70 machines and was completed in 1981. Later versions used VAX-11/780s. Today, LMOS runs on HP-UX
11i systems.
Local loop
In telephony, the local loop is the physical link or circuit that connects from the demarcation point of the customer premises to the edge of the carrier or telecommunications service provider's network...
s (telephone lines). When a problem is reported to the Centralized Repair Service Answering Bureau (CRSAB) by a subscriber dialing the designated number (often (1)+611) it is filed and relayed through the Cross Front End, which is a link from the CRSAB to the LMOS network. The trouble report is then sent to the Front End via the Datakit
Datakit
Datakit is a virtual circuit switch which was developed at Bell Labs for both local-area and wide-area networks, and in widespread deployment by the Regional Bell Operating Companies ....
network, where a Basic Output Report is requested (usually by a lineman working with). BORs consist of line information including past trouble history and MLT (Mechanized Loop Testing) tests. As LMOS is responsible for trouble reports, analysis, and similar related functions, MLT does the actual testing of customer loops. MLT hardware is located in the Repair Service Bureau. Test trunks connect MLT hardware to the telephone exchange
Telephone exchange
In the field of telecommunications, a telephone exchange or telephone switch is a system of electronic components that connects telephone calls...
s or Wire Centers, which in turn connect with the subscriber loops.
The LMOS database is a proprietary file system, designed with 11 access methods (variable index, index, hash tree, trie, fixed partition file, etc.). This is highly tuned for the various pieces of data used by LMOS.
LMOS, which was first brought on line as a mainframe application in the 1970s, was one of the first telephone company operations support systems to be ported to the UNIX
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
operating system. The first port of LMOS was to Digital Equipment Corporation
Digital Equipment Corporation
Digital Equipment Corporation was a major American company in the computer industry and a leading vendor of computer systems, software and peripherals from the 1960s to the 1990s...
's PDP 11/70 machines and was completed in 1981. Later versions used VAX-11/780s. Today, LMOS runs on HP-UX
HP-UX
HP-UX is Hewlett-Packard's proprietary implementation of the Unix operating system, based on UNIX System V and first released in 1984...
11i systems.