==Phrack Inc.== Volume One, Issue Nine, Phile #9 of 10 Loop Maintenance Operations System Written by Phantom Phreaker and Doom Prophet Part I: A basic overview of LMOS Part II:Mechanized Loop Testing Loop Maintenance and Operations System (LMOS) is a telephone company database that is a vital part in the act of repairing local loops (a customers telephone line). When you call the Repair Service to have your telephone service repaired, the information you give, as well as information and history on your local loop is processed through the LMOS database. This file shall examine several of the parts of LMOS, which is used by a number of different bureaus. The bureau that you reach when you dial your repair service is called the Centralized Repair Service Answering Bureau (CRSAB), and is usually reached by dialing (1)+611 or sometimes a POTS (Plain Old Telephone Service) number in areas where the X11 services aren't available. A CRSAB attendant is who you will deal with when reporting line trouble. You will tell the attendant the line number, and the types of problems you are experiencing on that line. The attendant will file a report concerning the basic information vital to line repair. Something called 'Front End Processors' form a 'real-time' interface between the customer reporting the trouble, and the CRSAB attendant. 'Real-Time ' means that it is done on a continually changing basis, (ex. while the customer is reporting the trouble to an attendant, action is being taken.) When a customer makes a trouble report to the CRSAB, the report is filed and sent through the Cross Front End, which is a link from the CRSAB to the LMOS system network. The trouble report is sent along a data link to the Front End, where a BOR (Basic Output Report) is requested. BOR's include line record information such as past trouble history and numerical values of MLT system tests. MLT is Mechanized Loop Testing. As LMOS is responsible for trouble reports, past trouble analysis, and other data related functions, MLT, which is connected to LMOS through a minicomputer in the Repair Service Bureau known as the MLT Controller, does the actual testing of subscriber loops. MLT hardware is located in the Repair Service Bureau. This hardware is linked to the LMOS system by way of an LMOS minicomputer, which may be in a remote location or with the LMOS central processor. Test trunks connect MLT hardware to the Wire Centers, which in turn connect with the subscriber loops. The Databases of LMOS are connected via a high speed data link. The major divisions of data handled by LMOS are listed below. Past Trouble History- This information is contained within the Abbreviated Trouble History (ATH) database and holds the most recent 40 days of history. The Trouble History (TH) database contains histories of troubles for the day. This TH database is used to support TREAT (Trouble Report Evaluation and Analysis Tool) reports. Line Record- These bases contain info about the customer's telephone circuit, whether it is POTS (for which there is a separate database), or SS (Special Service). Special Services numbers can be up to 16 characters plus the NPA or area code. The LMOS definition of an SS is any circuit having an identifier that is other than 10 digit numeric with NPA. Also, the Cable (CA), Associated Number (AN), Telephone Answering service (TAS), and Central Office Equipment (COE) data bases contain line record information as well. Miniline Record- There is one Miniline Record database for each Front End transaction processor. An example explaining this would be: A customer makes a trouble report to the CRSAB. The data sent through the Cross Front end to the Front End database, where a BOR is requested, is recorded and applied as status by the Miniline Record database to the Front End base. This helps to keep the LMOS Master Database in conjunction with the Front End bases. Service Order History- This base contains a list of all lines changed during the day. The list is used for construction of Miniline Records to be sent to the front ends. While there are many other databases within the LMOS system which serve a variety of functions, the bases listed above are the major ones. The telephone network is divided into two major pieces, the loop portion, or the line from a Central Office to the customer premises; and the Toll portion. This is the network that connects long distance offices such as the Toll center and Primary center, and is also known as the Direct Distance Dialing or DDD network. The LMOS database is customer and loop oriented. The loop portion of the network is frequently altered and changed, as it is the customer's link with the DDD network. These changes are tracked by LMOS. This type of activity falls into two categories: Customer initiated service requests (when a customer makes a request or trouble report), and Bell Operating Company initiated plant changes. 'Plant' is the Outside Plant of cable which makes up the local loop. A Customer initiated service request is for installation of new lines for the customer. The Universal Service Order or USO is the record of all these types of requests. USO's contain information such as customer listing, billing section, service and equipment section, and the Assignment section, which identifies the Central Office and outside plant (cable) facilities or lines. A BOC initiated plant change is called a work or job order. This is when the BOC serving the area make additions and rearrangements to loops to meet customer requirements for service. Examples of work orders include the following: Cable Throw-This order is when a cable pair is added to assist an existing cable in a high-growth area. This involves a change to the customer's cable and pair number. Cable Throw Summaries are printouts from this type of work order. Area Transfer-This order is used when Wire Centers, or the point where customer cable pairs branch out from, have to be balanced to compensate for growth, as there will be a need for more subscriber loops. This often involves the change of a customer's number. Service Orders pass through a BOC interface program to add RSB identifiers, which are repair unit numbers, needed by LMOS to translate data to a USO format. The Automatic Line Record Update (ALRU) system is a system that updates the data bases of LMOS in response to a service order. Work Orders can either involve a bulk task such as a large cable throw of 400 pairs from cable 102 to cable 109, which would use a special bulk-oriented program in the Work Order process, or smaller tasks concerning a few cables, which would use the Enter Cable Change or ECC transaction. Below is a summary of the Service Order flow through LMOS. 1: The customer requests new or changed telephone service for their line. 2: The request is entered into the BOC's service order network to be 'worked'. 3: A request is made to assign facilities necessary to install or modify the customer service. 4: Facilities are assigned and information is sent to the service order network. 5: The service order network forwards information to do work to the installer, or the RSB person who does the actual repair or modification on the line. 6: Installer completes work, returns notice to service order distribution network that service order has been completed. 7: Completed service order goes to the BOC interface program to perform data transactions for standard ALRU input. 8: A day's worth of service orders are accumulated and read into the ALRU. 9: Automatic Line Record Update automatically updates the LMOS host database. Next is a summary of the Work Order flow (for BOC initialized plant changes). 1: The Distribution Service Design Center forwards requests for loop facility additions or rearrangements to the Construction Maintenance Center to be worked. 2: If the request for work involves existing facilities (ones that are already there), facility assignment information is requested. 3: Facilities assigned to the Work Order are forwarded to the Construction Maintenance Center. 4: The Construction craft (installers) receives the work instructions. 5: Work is completed and notices are sent to the CMC. 6: A paper record of the completed work order is distributed to LMOS. When service order and work order activities are combined, an estimated 20 megabytes of data in the LMOS host data base is modified in some way every working day. Part II-MLT The basics of LMOS have been covered in part I. Part II will take a closer look at the Mechanized Loop Testing process and its relation with LMOS. As mentioned previously, the equipment for the MLT system is located in or near the Central Office or End Office in which the customer loops terminate. The MLT equipment (being a third generation of automated testing system) is connected by test trunks through the switching system to customer loops. The MLT controller located in the Repair Service Bureau enables tests to be made on up to 12 local loops simultaneously, sets up the testing sequence, and controls the connection of test equipment to the loops. To make the appropriate tests, information in the LMOS data base(s) about the customer loop and station equipment is transmitted to the MLT controller when the test request is initiated. This information controls certain phases of each test and is used to analyze and decipher test results. On command from the MLT controller, which will now be referred to as simply 'the Controller', the MLT system dials the number to be tested. If the line is busy, the cause is automatically determined (a conversation, phone off-hook, or a fault), and further tests are not made until the line is free. If the line is idle, the MLT system proceeds to make tests for purposes of maintenance and detection of faults in the loop. MLT test specifics * AC and DC (Alternating Current and Direct Current) measurements to determine if the loop is proper for the customer's station equipment, to determine the type and the extent of any electrical leakage through cable insulation, and to detect broken cable pairs and the location of the break in terms of distance from the CO where MLT is being used. * A 'Soak Test' to see if leakage will disappear after a high voltage is applied from the Central Office battery. The voltage dries up moisture, which is a frequent cause of leakage. * A Balance Check to reveal how susceptible the loop is to noise causing voltage, which would impair conversation over the line. * A measurement to tell whether CO battery voltage (voltage drops when the phone goes to an off-hook condition) and dial tone can be placed on the loop. All MLT test measurements are converted by the MLT hardware to digital form and returned to the Controller for analysis. The analysis is based on the test results and the line-record info from LMOS. Here is an example of how the Automated Repair Service Bureau (ARSB) works with the repair service attendants. A customer can't get a dial tone, so he calls the repair service from a neighbor's phone. An attendant who answers the call types the customer's phone number into a computer terminal. In response to this, LMOS displays the customer's name, address, class of service (in this case, it would be residential service), and information about any recent trouble on that loop. At the same time, LMOS causes the MLT system to test the loop. The CRSAB Attendant types in a description of the reported trouble. The MLT system returns the results of the tests on the line within a few seconds. Say, for example, the fault in question was a cable fault. This information would be displayed on the screen. The attendant would tell the customer that a visit is not needed, and that line will be repaired by a certain time. The data on the screen is automatically added to the LMOS database. A BOR is printed in the RSB serving the customer, and is screened to decide if it should be given to a dispatcher or a tester. The content of a BOR is explained in part one, and a diagram of a BOR is included below. **** BASIC OUTPUT REPORT ***** PAGE- 01 UNIT-99900000 10-08-86 0300P TTN-0000110 TN-999 5557009 CAT-CD SC-1FR CS-RES PUB CPE-NO SWC- WKNG -0- SMITH, JOHN 1000 NOWHERE LN. --RMKR-- --TRBL--NDT-CCO-CBC-ALL CALLS --RCH-- REACH NBR- COMM-10-09-86 0700P VER-4 CALLED NBR- OVER- STATUS-PS 10-09-77 0400P --STATUS NAR-- SO DATE 03-27-85 SO# N0901 --S/E-- QTY-0001 USOC-1FRBC KS-0000 LTD- REF- --ASGM-- OE-000B-010-09 VT-0146 RT-0500 NSTA-0001 BRG-N NSV-N WC-999 F1 NPA-999 CA- TT101 PR-109 PRU- BP-10 TEA-R1304 NOWHERE LN. --HIST-- NO REPORT SUBS CLEARED TH-KEY TST RPM O/S } T } D } C } 1 10-01-85 205P 0 10-02-77 0130P 10-02-77 620P 110 111 * }330}320}320} REPLACED INSIDE WIRE ------------------------------------------------------------------------------ MLT RESULTS SUMMARY: OPEN OUT, DISTANCE TO OPEN=39,200 FT OPEN OUT OPEN TIP DISTANCE TO OPEN 39,200 FT (FROM C.O.) VALID DC RESISTANCE AND VOLT VALID LINE CKT CONFIGURATION CAN DRAW AND BREAK DIAL TONE CONTL-01 LTF-01 PORT-09 TRUNK-123 EQU-TPK000 BYD007 DLR002 FRONT-END PROCESSING DATE AND TIME 10-08-76 0300P 370 PROCESSING DATE AND TIME 10-08-86 0302P ***END OF DATA*** This BOR tells that the trouble is an open tip wire 39,200 feet from the Central Office. The first part of the BOR up to the --RMKR-- is the basic information section. The second part, from --TRBL-- to SO DATE is the trouble section. The next part, from --S/E-- to TEA-R1304 is the assignment section. The fourth part, from --HIST-- up to REPLACED INSIDE WIRE is the Abbreviated Trouble History section. The last part is the MLT test results section. When a repair looks as if it may not be completed according to schedule, a Jeopardy Report is filed. Then, more repairmen are assigned to insure the line is repaired on time. After the repair is complete, the dispatcher retests the loop using MLT to verify that the trouble has been dealt with. The customer is notified, and the final disposition of trouble is entered into the LMOS database, where it is stored for future use and evaluation. (See also part I.) If you had to sum up LMOS, it would be best summed up by saying LMOS is 'A customer repair data management system.' Misc footnotes -------------- Section one: Acronyms ALRU-Automatic Line Record Update AN-Associated Number ARSB-Automated Repair Service Bureau ATH-Abbreviated Trouble History BOC-Bell Operating Company BOR-Basic Output Report CA-Cable COE-Central Office Equipment CMC-Construction Maintenance Center CRSAB-Centralized Repair Service Answering Bureau DDD-Direct Distance Dialing ECC-Enter Cable Change LMOS-Loop Maintenance Operations System MLT-Mechanized Loop Testing POTS-Plain Old Telephone Service RSB-Repair Service Bureau SS-Special Service TAS-Telephone Answering Service TH-Trouble History TREAT-Trouble Report Evaluation and Analysis Tool Section two: Automated Testing Systems MLT is the third generation of Automated Testing Systems. The first generation of testing equipment was something called the Line Status Verifier, which was manually operated, and not nearly as efficient as MLT or the second generation, the Automatic Line Verifier. The first and second generations of automated testing systems were both eventually built up to the MLT third generation type of system. -End of file- 8/19/86 ============================================================================== References and Acknowledgements ============================================================================== 'Automation improves testing and repair of customer loops' - Bell Labs Record 'Automated Repair Service Bureau' - Bell System Technical Journal And thanks to the following people for supplying other information: The Videosmith, The Marauder, Lock Lifter, Mark Tabas, and anyone else that we might have missed. Sysops are allowed to use this file as long as nothing is changed. This file was written in 80 columns, upper and lower case. If you notice any errors in this file please contact one of us and changes will be in order.