Testing Meridian Business Sets Using Predictor


Ameritech DMS, #5 ESS and Siemens central offices can provide a Centrex service that the rest of the central offices can't offer, called Integrated Information Network or IIN (Ameritech Digital Centrex).

This service allows the use of a new type of telephone called a Meridian Business Set (MBS).  However, the MBS can only be used in a DMS-type office.  What's unique about the MBS is a special "line card" (LEN) in the central office associated to the MBS's Primary Directory Number (PDN).  The "line card" allows 56 separate telephone numbers to be assigned to a single cable pair.

IIN service with Meridian Business Sets are not Mechanized Loop Test (MLT) testable.  Predictor is the vehicle that must be used when testing under these conditions.

Predictor is a computer based system that collects data from various systems where preset thresholds are involked to determine probable areas of trouble in the outside plant environment.  Predictor is part of the Automated Repair Service Bureau (ARSB) environment.

The following will be flow charts, sign-on and sign-off procedures, testing sequences and explanations for testing IIN MBS lines.

Basic MBS Trouble Report Flow

  1. Customer  Customer has trouble with their MBS.  Calls their Communications Representative.  Comm. Rep. calls the Centralized Repair Service Answering Bureau (CRSAB).
  2. CRSAB  Repair Service Attendant (RSA) must get PDN on Key #1.  Report is taken by asking specific questions.
  3. DSOC  Distribution Service Operations Center (DSOC) analyzes, tests, verifies, dispatches, refers and/or closes out report.
  4. Customer  The customer is notified of trouble dispatch, referral and/or closure of trouble report.

Sign-On/Off and Request Information

  1. DSOC analyzes the customer's trouble report and verifies and tests through Predictor.
  2. Sign-on to the Predictor and DMS systems.
  3. In Predictor, sign-on to Maintenance Administrative Position Command Interrogator (MAPCI).
  4. Perform MAPCI tests using the sequence shown.
  5. Based on results - dispatch, refer, clear, close.
  6. Communicate with the customer.



MAPCI Test Sequence Introduction

Basic MBS Trouble Report Flow - CRSAB

To assist the DSOC in analyzing the customer's trouble report, the RSA should ask the customer the following questions:

  1. Primary Directory Number on Key 1.
  2. Location of the Business Set.
  3. Complete description of the problem.
  4. Handle Code.
  5. Contact name and number.
  6. Time received and commitment.
  7. Send to DSOC.

Note - When received, make sure that the report is not involved with a cable trouble or service order activity.

Sign-On/Off Procedure for Predictor and DMS

MBS are unique in that you can't test them with Loop Maintenace Operations System (LMOS).  MBS will test as a short or open depending on the customer's equipment that is associated with the MBS.  MBS troubles must be tested using Predictor.  The following is the sign-on procedure to be used to verify and test MBS lines.

AT&T 6500 Terminal Sign-On -

  1. Obtain session that contains Predictor (usually D)
  2. Depress Command key
  3. Cursor to CH (Change Host)
  4. Depress Enter key
  5. Cursor to ASYNC MODEM
  6. Depress Enter key
  7. Check CAPS LOCK  (will use lower case)
  8. Depress PF3 for Modem/Dial
  9. Depress PF2 for Select
  10. Enter Predictor dial-up telephone number
  11. Depress PF1
  12. At login: enter ver  (lowercase)
  13. At Password: enter VER  (uppercase)
  14. Enter terminal VT100
  15. Response will be a $

At this point you are now signed-on to Predictor.

  1. Enter Query
  2. Enter Switch I.D.  (Wire Center's lowest NXX).
  3. Response will be a ?
  4. Enter login
  5. At User Name: enter LOCTST
  6. At Password: enter LOCTST

At this point you are now signed-on to the DMS switch.

Verify Directory Number (QDN) and LEN (QLEN).  Testing is also done at this level.

AT&T 6500 Terminal Sign-Off -

  1. Enter logout
  2. Response will be Bye Bye
  3. Depress Shift and the number 6
  4. Change Host (CH)

MBS will only work in a DMS-type office.  Since MLT cannot be used to properly test MBS, Predictor is your only vehicle for testing.  To test MBS with Predictor, you must gain access to the various "maintenance levels" in the DMS switch.  The Maintenance Level Flow Chart is shown below.

The various Maintenance Levels are:

To sign onto each of the Maintenance Levels, enter the following:

  1. Enter MAPCI
  2. Response MAPCI:
  3. Enter MTC
  4. Response MTC:
  5. Enter LNS
  6. Response LNS:
  7. Enter LTP
  8. Response LTP:

Once access is gained to the DMS switch, you now have access to various tests located within the levels you sign-on to.  There are five tests that must be performed on all trouble reports.  These tests are addressed next.

Note - Capital letters indicate other menus.  Regular letters indicate the tests.

Lines in use will show - line state in-appropriate, or line state invalid.

MAPCI Test Sequence Procedures

To properly analyze and test MBS trouble reports, the following tests must be run in sequence.  Any deviation could result in improper analysis and tests, and possibly even an irate customer.




To begin the testing sequence, you should have a printed copy of the Primary Directory Number (PDN) by using the Query Directory Number (QDN) command and a copy of the Line Equipment Number (LEN) information by using the Query Line Equipment Number (QLEN) command.

Note - When testing, turn on printer just prior to and at completion of testing.

To test a line, you must first "POST" the LEN, i.e., POST L XX X XX XX.  If you POST the Directory Number, you may get the Primary appearance of the Multiple Appearance Directory Number (MADN) LEN.  Now you are ready to perform the following test:

SUSTATE

This test is the first of five tests to be performed on the customer's line.  It will verify that the MBS and add-ons are responding to each software condition assigned.  To begin, select SUSTATE from the LTPMAN menu:

Type in LTPMAN
Response LTPMAN:
Type in SUSTATE

Note - Do not enter the Directory Number if the line in trouble is a MADN because the switch may enter the incorrect LEN and thus you would have the wrong telephone number.  Upon successful entry your response should be:

ADDRESS       0   1   2   3   4   5   6   7
DATA FILLED   .   _   _   _   _   _   _   _
RESPONDING    .   _   _   _   _   _   _   _

. = What is programmed in the switch for a directory number for an address

_ = Switch doesn't recognize the MBS equipment responding or the switch
    hasn't been programmed for a directory number for each address.

In other words, this is a comparison between what's programmed in the switch and what's in the field.

Example of improper response:

ADDRESS       0   1   2   3   4   5   6   7
DATA FILLED   .   .   _   _   _   _   _   _    (MBS w/add-on)
RESPONDING    .   _   _   _   _   _   _   _    (Add-on not responding)

Note A - When an address (0-3) has a (.) under it, it would indicate the following:

Note B - When an address (4-7) has a (.) under it, it would indicate the following:

Note C - Further action my be required based on SUSTATE results.

Note D - The SUSTATE test should be performed 5 times in succession to ensure proper responses from MBS.

Enter Repeat 5(SUSTATE)

Note E - At times you may encounter an "ERROR".  Be sure to read what the error message is.  In most cases, when you go to reenter your request, do not retype the command.  The switch already knows what command you entered so just reenter the DN or LEN.

If you make an error for the "command" entry, i.e., QND instead of QDN, you get an error message directed to the command.

CKTST - Circuit Test

This is the second of five tests to be performed on the customer's line.  It will verify that the components or computer chips of the MBS are working properly.  To begin, select CKTTST from the LTPMAN menu:

Type in CKTTST

The switch will respond in the following manner:

Messages Sent = 10
Messages Received = 10

The results are an indictator that the MBS is responding correctly to messaging.  The test signals are addresses internal to the MBS and each message sent expects proper responses from each component in the MBS.  If the results are not equal (10 and 9), the MBS is defective and should be replaced.  Refer the customer to their vendor.

Note A - This test must be performed 5 times to ensure proper operation of the internal components of the MBS.

Enter Repeat 5(CKTTST)

Note B - Messaging is sent to the MBS at 8 kHz from the line card in the central office.  Messages are sent out on the ring side of the facilities and returned on the tip side.

LNTST - Line Test

This is the third of five tests to be performed on the customer's line.  It will verify and test the loop facilities.  To begin, select LNTST from the LTPMAN menu:

Type in LNTST

The switch will respond in the following manner:

                RES         CAP     VAC   VDC   
TIP           999.K     2.055UF     0     0 
RING          999.K     1.055UF     0     0
TIP to RING   999.K     1.005UF     0     0

The above results could indicate an open ring side out in the field.

                RES         CAP     VAC   VDC
TIP           999.K      5.00UF     .5    .5  
RING          999.K      5.00UF     0     0
TIP to RING   999.K      5.00UF     0     0

The above results could indicate a faulty MBS or facility problem.  VAC and VDC should be zero.

                RES         CAP     VAC   VDC
TIP           999.K      5.00UF     0     0 
RING           10.K      5.00UF     0     0
TIP to RING   500.K      5.00UF     0     0

The above results could indicate a ground on the line.

                RES         CAP     VAC   VDC
TIP           500.K      0.00UF     0     0
RING          500.K      0.00UF     0     0
TIP to RING    10.K      0.00UF     0     0

The above results could indicate a short on the line.

                RES         CAP     VAC   VDC
TIP           999.K      2.86UF     0     0
RING          999.K      4.79UF     0     0
TIP to RING   999.K      5.00UF     0     0

The above results could indicate a Non-Display MBS.

Note B - Perform this test only once.  Repeated tests will reduce the capacitance.

Note C - Mark down what a good test looks like to various customers.

DIAG LC - Diagnostic Line Card

This is the fourth of five tests to be performed on the customer's line.  It is used to test the operation of the line card located in the central office that is assigned to the customer's LEN.  To begin, select DIAG from the LTPMAN menu.

Type in DIAG LC

The results may look like the following:

Attempting to Diagnose Line Card only
MILWWI13DS0***+LINE 100 JAN 25 08:56:49 4700 PASS LN_DIAG
     LEN HOST 01 1 17 14  DN 2270077
     DIAGNOSTIC RESULT  CARD DIAGNOSTIC OK
     ACTION REQUIRED NONE
     CARD TYPE 6X21AC

If the line card test "fails", you should do the following:

  1. Change the line card.  (first priority)
  2. Check facilities.

DIAG - Diagnostic

This test is the last test to be performed on the customer's line.  It will test the entire line.  To begin, select DIAG from the LTPMAN menu.

Type in DIAG

The DIAGNOSTIC test looks at the following items:

The result may look like the following:

MILWWI13DS0***+LINE 100 JAN 25 09:04:01 9000 PASS LN_DIAG
     LEN HOST 01 1 17 14  DN 2270077
     DIAGNOSTIC RESULT CARD DIAGNOSTIC OK
     ACTION REQUIRED NONE
     CARD TYPE 6X21AC

If the results are as indicated above, verify with customer.