UNITED STATES DEPARTMENT OF AGRICULTURE

Rural Utilities Service

BULLETIN 1753E-201

RD-GD-1996-21

SUBJECT: Acceptance Tests for Digital, Stored Program Controlled

Central Office Equipment

TO: All RUS Telecommunications Borrowers

 RUS Telecommunications Staff

EFFECTIVE DATE: Date of Approval

EXPIRATION DATE: Seven years from effective date

OFFICE OF PRIMARY INTEREST: Central Office Equipment Branch, Telecommunications

Standards Division.

FILING INSTRUCTIONS: This bulletin provides information formerly contained in Bulletin

384-2, Closeout Documents for Central Office Contracts, issued September 13, 1961, and

rescinded February 23, 1990. File with 7 CFR 1753 and is available to RUS staff on RUSNET.

PURPOSE: This bulletin provides acceptance tests that demonstrate compliance with the

requirements of RUS Form 522 General Specification for Digital, Stored Program Controlled

Central Office Equipment.

_____________________________ __________________

Administrator Date

Disclaimer: The contents of this guidance document does not have the force and effect of law 

and is not meant to bind the public in any way. This document is intended only to provide 

clarity to the public regarding existing requirements under the law or agency policies.
Bulletin 1753E-201

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TABLE OF CONTENTS

1. Introduction ..................................................................................4

2. Switch Acceptance Tests ..................................................................................4

3. Line Testing Procedure ..................................................................................7

4. Interoffice Trunk Tests ..................................................................................9

5. Alarms ................................................................................10

6. Power Equipment ................................................................................10

7. Main Distributing Frame ................................................................................11

8. Subscriber Loop Test Facility ................................................................................11

9. Ringing Generators ................................................................................11

10. Tones and Tone Levels ................................................................................12

11. Line Load Control ................................................................................12

12. Switched Access Service ................................................................................12

13. Plant Registers ................................................................................13

14. Fire Call Equipment ................................................................................13

15. Drawings and Printed Material ................................................................................13

16. Processor Tests ................................................................................13

17. Redundancy ................................................................................15

18. Transmission Tests ................................................................................16

19. RST Units ................................................................................16

20. Additional Tests ................................................................................17

21. SS7 Testing ................................................................................17

CHECKLISTS

Master Checklist ................................................................................18

Checklist A ................................................................................20

Checklist B ................................................................................21

Checklist C ................................................................................22

Checklist D ................................................................................23

Checklist E ................................................................................24

Checklist F ................................................................................25

Checklist G ................................................................................26

Checklist H ................................................................................27

Checklist I ................................................................................28

Checklist J ................................................................................29

Checklist K ................................................................................31

Checklist L ................................................................................32

Checklist M ................................................................................33

FIGURES

Figure 1 - Test Line A ..................................................................................5

Figure 2 - Test Line B ..................................................................................6

TABLE

Table 1 - Minimum Number of Lines, or Trunks in a Trunk Group by

Size (Two-Trial Method) ....................6

INDEX:

Testing, Acceptance
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ABBREVIATIONS

AMA Automatic Message Accounting

ANI Automatic Number Identification

BV Busy Verification

CFR Code of Federal Regulations

CRT Cathode Ray Tube

dB Decibel

dBmO Decibels at 1 milliwatt measured at 0 transmission level

dBrnC Decibels above reference noise, C-message weighted

Hz Hertz

I/O Input/Output

IP Informational Publication

LATA Local Access and Transport Area

MF Multifrequency

NXX General term for central office codes

REN Ringer Equivalence Number

ROH Receiver Off-Hook

RST Remote Switching Terminal

RUS Rural Utilities Service

SS7 Signaling System 7

VF Voice Frequency
Bulletin 1753E-201

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1. INTRODUCTION

1.1 The switching system acceptance tests specified in this bulletin should be made by the Owner

or its Engineer before the equipment is placed into service or accepted for final payment. The

acceptance test instructions, checklists, and guidance presented in this bulletin are based on the

requirements of Part 1 of RUS Bulletin 1753E-001, "General Specification for Digital, Stored

Program Controlled Central Office Equipment (Form 522)." Paragraph references in this bulletin

refer to Bulletin 1753E-001, Part I, unless specifically stated otherwise. Although this bulletin

was developed with new digital switches in mind, much of the material is also applicable for

acceptance testing of additions and upgrades.

1.2 Certification should be obtained from the supplier that the equipment is ready for testing, and

arrangements should be made with all connecting companies before starting any call tests. The

configuration of system software and equipment and the complexity of operating and diagnostic

tests make it desirable to conduct a number of these tests with the assistance of the equipment

supplier's representative. The diversified design and applications of the various makes of digital

switches require flexibility in the implementation of acceptance tests. Special considerations

should be made for test processes on additions and upgrades to "on-line" systems on a case by

case basis. Any acceptance test procedures provided by the switch supplier should be reviewed

and used if deemed satisfactory.

1.3 In addition to the tests included in this bulletin the Owner or its Engineer should develop

procedures and methods to test special features in the particular system.

1.4 Before any system acceptance tests are conducted, a physical inspection of the quality of

workmanship and appearance of the installation should be made. This is to be followed by an

inventory to ascertain that all required equipment has been installed.

2. SWITCH ACCEPTANCE TESTS

2.1 Load Box Testing: For an overall test that the system is ready to start handling traffic, a

load box is a powerful test instrument.

2.1.1 There are two basic load box testing methods:

a. A number of originating lines are randomly seized and a group of directory numbers are

randomly dialed and;

b. Multiple originating lines are seized simultaneously and a single directory number is

dialed by all originating lines.

Method (a) is an excellent means to test the system’s ability to complete normal subscriber calls.

A minimum of ten (10) lines originating and ten (10) lines terminating are recommended. Method
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(b) is normally used for testing system distribution and queuing functions but is not a true

indication of the system’s overall ability to handle random traffic.

2.1.2 A load box is not required for owner acceptance testing (paragraph 3.3). However, it is

advantageous to observe the operation of the supplier's load box and make an analysis of the data

from the test equipment, rather than the central office equipment, to determine that the machine is

meeting the requirement of no more than two lost calls in 10,000 (paragraph 3.2). If the machine

fails the two lost calls in 10,000 criterion, corrective action by the supplier should be taken.

2.2 Test Line Requirement: For acceptance testing, two test lines are required; one to simulate

a short loop and one to simulate a 1900 ohm loop.

2.2.1 Test line A is shown in Figure 1. The dialing mechanism consists of two 500 type

telephone sets (one dial-pulse, one DTMF) equipped with ringers of the lowest frequency

supplied by the switching equipment, or test equipment with the capability of dial-pulse and

DTMF signaling and an equivalent ringer impedance of a 500 type telephone set. It should be

possible to connect this test line to various lines throughout the switching system. This line is

equivalent to a short loop.

Figure 1

Test Line A

25 κΩ

5 κΩ

2 μF

T

DIALING

MECHANISM

R

2.2.2 Test line B is shown in Figure 2. This test line provides a nominal 1900 ohm loop

resistance when connected to a dialing mechanism with a 200 ohm resistance. The dialing

mechanism consists of two telephone sets or test equipment capable of both dial-pulse and DTMF

signaling. The mechanism should also include a sufficient number of bridged high impedance

ringers to provide a Ringer Equivalence Number (REN) of five. This test line should also be

movable from line to line throughout the system.
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Figure 2

Test Line B

T

R

850 Ω

850 Ω

DI ALIN G

MECHANISM

2.3 Sample Sizes: The number of lines or trunks to be tested should be determined from Table

1. The complexity and amount of time consumed in making each individual test should also be

considered when choosing the test sample sizes.

TABLE 1

Minimum Number of Lines, or Trunks in a Trunk

Group by Size (Two-Trial method)

Total Number of Trial 1 Trial 2 Threshold

Lines in Office or

Trunks in a Group

Lines or

Trunks (1)

Lines or

Trunks (2)

of System

Failure (3)

 1 - 25 All -- 0

 26 - 50 26 -- 0

 51 - 100 33 17 1

 101 - 200 43 22 1

 201 - 300 47 28 1

 301 - 400 49 31 1

 401 - 600 50 30 1

 601 - 800 50 35 1

 801 - 1,000 55 30 1

 1001 - 2,000 55 35 1

 2001 - 3,000 65 80 2

 3001 - 20,000 70 80 2

Notes:

1. Minimum quantity to be tested. If a single failure is encountered during Trial 1,

complete Trial 1 and then perform Trial 2.

2. Additional quantity to be tested if a failure is encountered during Trial 1.

3. Total number of failures permitted for both trials.
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2.3.1 Table 1 call volumes will produce results with a 99 percent confidence level that a system

which has gone through all manufacturer's tests will meet the criterion of having only a 0.02

percent (2 calls failed per 10,000 attempts) or less expected defective rate (paragraph 3.2). This

is a two-trial test and should be considered the minimum sample size to be tested in a system. If

the system passes Trial 1, Trial 2 is omitted. Table 1 is to be considered a minimum sample size

for the number of subscriber lines in the office or trunks in trunk groups. A larger sample may be

used if considered necessary.

2.3.2 The number of test calls that should be made per test line are described in item 3.1 of this

bulletin.

3. LINE TESTING PROCEDURE: Determine which of the line terminals will be used for

originating calls and which will be used for terminating calls. The number of lines to be tested

using dial-pulse or DTMF signaling can be determined in accordance with the percentage of lines

configured for such signaling in the office but no less than 25% of the tests should be made using

dial-pulsing.

3.1 Test Line A: Use test line A for originating test calls on a randomly selected group of lines

in agreement with the quantities spelled out in Table 1. The originating calls should be directed to

as many terminations and types of terminations as time permits. Each line should be directed to

no less than one terminating subscriber line and at least two calls should be routed through all

available trunk groups to check for proper trunk selection. Follow the requirements of Table 1

for failures. Use Checklist A.

3.2 Test Line B: Using test line B for terminating tests, check the sample lines for proper

termination operation. These are ring, ring trip, supervision and talking. Follow the requirements

of Table 1 for failures. Use Checklist A.

3.3 1900 Ohm Loop: Reverse test lines A and B and make enough tests to ensure that the

system will work with an originating 1900 ohm loop. Use Checklist A.

3.4 Progress Tones: Check for call progress tones. Use Checklist A.

3.5 Lockout: The line equipment should be seized but no digits dialed. When time-out occurs,

the sequence of tones should be observed. The line on lockout should be automatically cleared

from that condition and arranged for normal line seizure on a subsequent off-hook condition when

the permanent off-hook condition is cleared. Refer to paragraph 6.4. Use Checklist B.

3.6 Timing Checks: The following timing checks should be made. Use Checklist B.

3.6.1 Check ringing cycle. Refer to paragraph 19.6.2.
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3.6.2 Check for permanent signal timing by seizing the line equipment but not dialing. Refer to

paragraph 18.3.

3.6.3 Check for partial dial timing by dialing the first two digits and waiting for lockout. Refer to

paragraph 18.4.

3.6.4 Check for called party disconnect. Refer to paragraph 18.7.

3.7 Vertical Services: Where vertical services are available, test these from a properly class

marked line. Since the RUS specification does not spell out the exact operating procedure for

these services, it is necessary to use the supplier’s description of their operation, how to place

them in service, and activate them from the subscriber's telephone. Refer to paragraph 5.5. Use

Checklist B.

3.8 Nuisance Trap: Where a nuisance trap is provided, make a call to a terminating line that has

been so marked and check the operation. Refer to paragraph 7.9. Use Checklist B.

3.9 911 Service: When basic 911 emergency service is provided, make a 911 call and verify that

911 is routed to the proper lines or trunks. If additional 911 features are provided, refer to

paragraphs 5.19 through 5.19.9 for parameters. Use Checklist B.

3.10 Semi-Postpay Pay Stations: Check the operation of semi-Postpay pay stations if they are

equipped. If the pay stations use the regular toll trunks, originate a call to the operator and check

for spurt of low tone to the operator and make certain it cannot be heard at the pay station. The

operator should be able to repeat this tone. Check that conversation with the operator, 911 or

other emergency numbers is possible without depositing a coin. On local-to-local calls, check that

the calling pay station cannot talk without deposit of coin after answer by the called party. Check

that all calls to pay stations class marked to receive calls can be answered without coin deposit.

Check that the pay station can handle 1+ and 0+/0- calls in the appropriate manner, the operator

can ring back the pay station, and deposited coins are collected. Use Checklist C.

3.11 Prepay Pay Stations: On calls to the operator, if regular operator trunks are used, check

for spurt of low tone to the operator and make sure it cannot be heard at the pay station. Make a

call to the operator from the pay station and to a local number and check for collect and refund in

each instance. Check that conversation with an operator, 911 or other emergency or coin-free

numbers is possible without coin deposit. Check for transmission in both directions. Check for

operator ringback to the pay station. Check that all calls to pay stations class marked to receive

calls can be answered without coin deposit. Check that the pay station can handle 1+ and 0+/0-

calls in the appropriate manner. Use Checklist C.

3.12 Intercept: Dial unassigned directory numbers and office codes to determine if the calls are

routed to intercept. The calls are to be routed as required in RUS Form 522, Part III, item 10.2.

Place an assigned directory number on changed number intercept and dial it to determine that the
Bulletin 1753E-201

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proper option as required in RUS Form 522, Part III paragraph 10.2, is provided and is operating

satisfactorily. Refer to paragraph 7.8. Use Checklist C.

3.13 PBX Rotation: Establish a PBX group in the system. The minimum number of lines in the

group should be three for the test. Connect a telephone to each line. Dial the assigned PBX

directory number from the test line. When the first phone rings, answer and leave off-hook.

Continue to dial the PBX access number until all lines have been busied out, then test for line busy

tone. Check the ability to assign one line in the PBX group as non-hunting for night service. Use

Checklist C.

4. INTEROFFICE TRUNK TESTS: The minimum sample size is determined from Table 1.

4.1 Outgoing: Access the two-way and one-way outgoing trunk groups from subscriber lines in

several different line groups. Attempt seizure of all trunks in the trunk group. On VF trunks,

access the signaling circuit, check out pulsing of dial pulses or MF tones to determine that the

registers are operating properly. Make a talking test by connecting a telephone instrument with

proper impedance matching equipment to the frame side of the trunk. This can be done at the

jacks provided. Use Checklist D.

4.1.1 If the trunks are direct digital connected (no channel bank) and the connecting office is not

ready for tests, the trunks can be connected to a portable channel bank, or appropriate test

equipment, in order to make the proper voice frequency and signaling tests.

4.2 Incoming: If the connecting office is prepared for tests, this is obviously the simplest

method of making inward trunk tests. This is not likely to be the case; therefore, other methods

should be used and the connecting company equipment simulated. For inward voice frequency

trunk testing, a test set can be plugged into the line side jack of two-way or incoming trunks and

the tests made inward on loop dial trunks. For E & M trunks, the E & M leads are to be accessed

with the test set for signaling inward; and calls completed to a local line and or another trunk in

case of tandem switching. In each case, a talking test should be made to ensure continuity. Use

Checklist E.

4.2.1 If the trunks are direct digital connected and the connecting company is not ready for tests,

a portable channel bank, or appropriate test equipment, can be used to simulate the distant end.

The trunk should be pulsed with the proper mode. For dial pulse signaling, a simple telephone

will suffice; but if MF signaling is required, an MF sending test set is needed.

4.3 Busy Verification: Place a call between test lines or from one line to the milliwatt terminal.

If possible, have the connecting company verify the connection. If this is not possible, access the

busy verification trunk (or toll completing trunk) from the distant office end either by a portable

channel bank if the trunk is direct digital connected or jack access if the trunk is VF. Dial the BV

access code shown in RUS Form 522, Part III, item 10.1.2. Also access the call from the
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maintenance center or appropriate test center. Check that proper transmission can take place

between all parties. Use Checklist E.

5. ALARMS

5.1 Alarm Sending and Checking: Check alarms by causing a trouble indication in each level

of alarm. Determine that the alarm is sent to the proper trunk or trunks, that on answer of these

trunks a distinctive tone is given and that the operator, or equivalent, can release the trunk by

dialing the alarm checking number over another trunk. Determine that a higher priority alarm will

override an alarm seizure by a lower priority alarm. Dial the alarm checking number, and

determine that the proper alarm indication is given. Refer to paragraph 15.1. Use Checklist F.

6. POWER EQUIPMENT

6.1 Charger Voltage Settings: Check the operation of the charger against the operating

instructions supplied by the manufacturer. The equalizing voltage should not exceed the upper

limit of the operating voltage specified by the central office equipment supplier. Use Checklist G.

6.2 Charger Noise

6.2.1 Electrical: Measure electrical noise as indicated in paragraph 19.3.3. Use Checklist G.

6.2.2 Audible: A conclusive test of acoustic noise is detailed in paragraph 19.3.5. Use Checklist

G.

6.3 Charger Inventory: The number of chargers supplied are to meet the requirements of

paragraph 19.3.8 for central offices and 23.6.1 for remote switching terminals. Use Checklist G.

6.4 Batteries: Inspect the condition of the batteries, especially the items in the following

paragraphs. Use Checklist G for all battery tests.

6.4.1 Check cell voltages. If low voltage conditions exist, an equalizing charge should be applied

in accordance with manufacturer’s recommendations.

6.4.2 Check the specific gravity of each cell. Refer to paragraph 19.2.4 and the manufacturer’s

recommendations.

6.4.3 Check that the electrolyte level is within the limits prescribed by the manufacturer.

6.4.4 Make certain the initial conditions of the battery are recorded on the maintenance record

and that the proper instruments (RUS Form 522, Part III, items 12.1.3 and 12.1.4) are supplied if

required.
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6.4.5 Check for faulty or cracked containers.

6.4.6 Cells or units should be checked for proper spacing and to ensure that they are not touching

(approximately 1/2 inch spacing between cells is customary).

6.4.7 Check that all connections are tight and torqued to the supplier's specifications.

6.4.8 Ensure that no cell top touches the metal of a rack or cabinet or any other piece of

equipment.

6.4.9 Check that each cell is equipped with an explosion control device.

7. MAIN DISTRIBUTING FRAME

7.1 Check that the main frame protectors furnished are listed in RUS Informational Publication

344-2, “List of Materials Acceptable for Use on Telecommunications Systems of RUS

Borrowers.” Ensure that the distributing frame provides adequate facilities for testing all lines.

Check that all outside plant pairs are equipped with acceptable protector mountings and arresters

or grounding modules. Check that the distributing frame can terminate the number of cable pairs

listed in RUS Form 522, Part III, item 13.1. Use Checklist H.

8. SUBSCRIBER LOOP TEST FACILITY

8.1 A subscriber loop test set, or equivalent, should be used to make the tests shown in

paragraph 15.2.3.1. Test each function and record the results. Use Checklist H.

8.2 If the same tests of subscriber lines in remote switching terminals (RST’s) are not possible

from a centralized location, then a separate means of making these tests should be provided. Use

Checklist H.

9. RINGING GENERATORS

9.1 The ringing generators should be provided in accordance with paragraph 19.5. If the ringing

power is generated integral to the switching system, it should meet the required output voltages,

voltage regulation, cross ring requirements, frequency stability and other parameters specified in

paragraph 19.5. Use Checklist H.

9.2 Check the output voltage of each frequency to determine that they meet the values specified

in item 19.5. Use Checklist H.
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10. TONES AND TONE LEVELS

10.1 Listen to and measure the various call progress tone levels. The levels are to be measured at

the MDF with a suitable dB measuring device. Refer to paragraph 9.2. Use Checklist I.

11. LINE LOAD CONTROL

11.1 When line load control is specified, the Owner should specify which lines are to be assigned

to each level of line load control priority provided. It should be tested in whichever mode is

supplied and the lines for each priority tested for ability to originate and complete calls. Make

certain that lines without priority cannot originate calls or tie up circuits in any manner. Use

Checklist I.

12. SWITCHED ACCESS SERVICE

12.1 Feature Groups: Verify that the proper Feature Groups have been furnished. Use

Checklist I.

12.1.1 Verify that all appropriate carriers have been assigned to the proper feature group.

12.1.2 Place a call to all assigned carriers and verify the proper signaling sequence and carrier

identification.

12.1.3 Verify that calls originating from coin lines toward switched service provide TSPS-type

signaling or are blocked.

12.2 Equal Access: In Feature Group D, verify equal access capability. Use Checklist I.

12.2.1 Verify that presubscribed customers do not have to dial the carrier access code.

12.3 Automatic Number Identification Equipment (ANI): The ANI equipment should be

connected to a suitable test set. If required, a portable channel bank, or appropriate test

equipment, can be used to convert the digital signal to analog. There is a possibility that a digital

to analog trunk, such as an intercept trunk to a recorder, can be temporarily assigned to the AMA

trunk group and used for this test. Use Checklist I.

12.3.1 Verify the calling and called numbers.

12.3.2 Verify that the proper billing information is sent to the AMA equipment.

12.3.3 Verify remote polling capability if that feature is required.
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13. PLANT REGISTERS

13.1 In stored program controlled central offices, the traffic recording is done in the processor

memory. If there are traffic or other types of registers supplied with the system, determine that

they perform the function for which they are supplied. Refer to paragraph 16.4. Use Checklist I.

14. FIRE CALL EQUIPMENT

14.1 The fire call equipment and features should be checked in accordance with the operation of

the system provided. Use Checklist I.

15. DRAWINGS AND PRINTED MATERIAL

15.1 Check that the required sets of drawings and instructions are available. Refer to paragraph

24.3. Use Checklist I.

15.2 Make certain that there is sufficient detailed material to allow the maintenance people to

operate the I/O information terminal of the system. Use Checklist I.

15.3 Check that the floor plan includes space reserved for future additions and make certain the

dimensions shown on the drawing coincide with the equipment as installed and the actual

dimensions of the building. Use Checklist I.

16. PROCESSOR TESTS

16.1 Common Processor Equipment Transfer (Manual and Automatic):

Ensure that all manufacturer’s instructions for verifying redundant systems and inducing failures in

the system are adhered to prior to making any redundancy checks. If possible, these tests should

be made before the central office is cut into service. The purpose of this test is twofold: first, to

verify that automatic and manual transfer of redundant equipment operates; and secondly, to

verify that the redundant processor equipment functions properly. Test calls should be made

before and after each transfer. Check that established calls are not lost due to the transfer.

Typically, the following circuits should be checked, as applicable: processor, memory, clock, and

time slot interchange. This listing is not meant to be all-inclusive. Every redundant circuit should

be tested, where practicable. Use Checklist J for all processor and synchronization tests.

16.1.1 The above test should also be made to check the operation of the automatic transfer

features.
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16.2 Clock Synchronization:

16.2.1 The central office clock and network synchronization system requires the ability to

synchronize with external clocks for network synchronization, including detection of slips, timing,

jitter and wander, in a digital-to-digital environment. It is also required to operate in an

independent mode without significant loss of accuracy or stability when there is an external loss of

frequency reference. Checklist J includes tests that will verify the above.

16.3 Administrative Functions: All the following functions should be able to be performed

locally as well as remotely if required.

16.3.1 Directory Service Orders

16.3.1.1 Verify that the list of directory numbers can be printed out in numerical order with their

assigned class of service;

16.3.1.2 Verify that all information regarding directory numbers can be printed out. This should

include lines on lockout, intercept, unassigned, etc., as described in paragraph 14.4.

16.3.1.3 Enter a directory number and alter the information. Verify that the change is made; and

16.3.1.4 Verify that a list of equipment’s busied out for maintenance can be printed out.

16.3.2 Trunk Group Information

16.3.2.1 Verify that the trunk group numbers can be printed out in numerical order.

16.3.2.2 Enter the hunt group number of any assigned trunk hunting group and verify that the

system prints out all the information for that group;

16.3.2.3 Enter a valid trunk hunt group number and delete a trunk from that group. Verify that it

was deleted; and

16.3.2.4 Add the trunk deleted in paragraph 16.3.2.3 above to the appropriate trunk hunt group.

Verify that the trunk has been added to the trunk group.

16.3.3 Line Class of Service Information

16.3.3.1 Verify that a numerical list of all line classes of service can be printed out by the system;

16.3.3 2 Enter a valid line class of service number and verify that all the information for that

number is printed out;
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16.3.3.3 Enter information necessary to create a new class of service. Verify that the system

responds appropriately;

16.3.3.4 Verify that the system deletes the class of service number created in paragraph 16.3.3.3

above;

16.3.3.5 Enter an existing line class of service number and modify its characteristics. Verify that

the changes have been made; and

16.3.3.6 Enter a valid line class of service number and verify that the system prints out all

equipment numbers referencing that line class of service number.

16.3.4 Translator Table Information

16.3.4.1 Verify that all applicable office codes (NXX) are printed out by the system in numerical

order;

16.3.4.2 Enter a valid NXX code and verify that all information for that code is printed out; and

16.3.4.3 Enter a valid NXX code and modify the information for that code. Verify that the

system entered the changes.

16.3.5 Memory Reload Test: Clear the switch database memory. Follow the manufacturer's

procedures to reload the switch database memory. Check the amount of time necessary to reload.

This should be within the manufacturer’s parameters for that switch. Also check the accuracy of

the stored information.

16.3.6 System Diagnostics Tests: Check the major diagnostics programs following the

procedures given by the manufacturer. Print outs should be checked for proper information.

16.3.7 Check the traffic output on the I/O device.

16.3.8 Care should be taken to ensure that whenever valid information is changed during these

tests it is restored to its original form.

17. REDUNDANCY

17.1 Ensure that all manufacturer’s instructions for verifying redundant systems and inducing

failures in the system are adhered to when making any redundancy checks. If possible, these tests

should be made before the central office is cut into service. Check that all redundant systems

operate properly on failure of the on-line system. Simulated failures should be made in each

redundant item, such as processors, clocks, time slot interchanges, ringing machines, and power

converters. Determine that the system is still functioning, that the proper alarm, if required, is
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sent, and a printout is provided on any display equipment that is used for maintenance. Use

Checklist J.

18. TRANSMISSION TESTS

18.1 General: The tests shown here are a minimum and do not preclude the making of other

transmission tests if time and instruments are available. These tests are intended to spot check the

system to make certain that the quality control of the switch manufacturer is consistent with the

parameters described in the specification. A minimum of 10 lines and 10 trunks, randomly

selected, should be tested. Refer to paragraph 17 for transmission tests guidelines when needed.

Use Checklist K for all transmission tests.

18.2 Insertion Loss: All insertion loss tests should be made in both directions. The number of

lines tested are to be equally divided between originating and terminating. During trunk tests to

and from subscriber lines it is satisfactory to use a line which is known to have satisfactory

transmission ability from the line tests. If the trunk to be tested is direct digitally connected, a

portable channel bank, or appropriate test equipment, may be used. It is suggested that a 3 dB

loss be set in the channel bank and then a 3 dB to 3.5 dB loss should be measured through the

office to the subscriber line terminal. Refer to paragraph 17.3.

18.3 Frequency Response: The frequency response measurements are made in the same manner

as the insertion loss measurements but with an input that varies over the required frequency range.

Refer to paragraph 17.4.

18.4 Idle Channel Noise: This test is best made with as much traffic as possible on the system.

If a load box or other device is operating, this will be ideal. Make a call to a line terminated in a

900 ohm impedance and connect a noise measuring set to the originating line. Refer to paragraph

17.10.

18.5 Quantizing Distortion: The quantizing distortion test should be made in both directions.

The number of lines tested are to be equally divided between originating and terminating. The

test is made by inserting a O dBm 1004 Hz signal in the send line and measuring C-msg noise

using a 1004 Hz notch filter at the receive end. Refer to paragraph 17.13.

19. RST UNITS: Use Checklist L for all RST tests.

19.1 Check the lines in the same manner as the host office, using the same criteria for the number

of lines tested.

19.1.1 Make tests for all operational features made on the host office, such as tones, intercept,

trunk access, and time-outs.
Bulletin 1753E-201

Page 17

19.1.2 If the RST unit is required to complete calls within itself when the link to the host office

has been severed, this will be shown in Form 522, Part IV, paragraph 6. Check that the RST will

operate as described when the link to the host office is disabled.

19.1.3 Check the amount of equipment supplied and determine that the traffic per line is met or

exceeded by the links to the host office and interlinking if applicable.

19.1.4 Check charger(s) and batteries, including required battery size.

19.1.5 Check the equipment housing for proper environmental control, such as temperature,

humidity, and air cleanliness, in accordance with the manufacturer's specification.

20. ADDITIONAL TESTS: Use Checklist M

20.1 The borrower or its engineer may develop procedures and methods for additional tests.

Checklist M has been prepared as a vehicle for listing these additional tests and verifying that they

have been performed.

21. SS7 TESTING

21.1 Because the Rural Utilities Service (RUS) has not yet written a specification for SS7

equipment, no RUS test acceptance procedures have been developed. However, it is

recommended that all acceptance procedures of the SS7 equipment manufacturer be performed,

as well as any additional tests recommended by the terminating office of the SS7 equipment.
Bulletin 1753E-201

Page 18

MASTER CHECKLIST

The following is a summary of tests covered by this bulletin and the checklist with which they are

associated. It is meant as an aid in recording who is responsible for making the tests and if they

were completed. The Paragraph column in this checklist only refers to paragraph numbers in

this bulletin. The completion of this checklist is not a requirement of the test acceptance

procedure.

Paragraph Test Checklist Assigned to: Completed

3. LINE TESTING PROCEDURES

3.1 Test Line A - Originating A

3.2 Test Line B - Terminating A

3.3 1900 Ohm Loop - Line reversal A

3.4 Progress Tones A

3.5 Lockout B

3.6 Timing Checks B

3.7 Vertical Services B

3.8 Nuisance Traps B

3.9 911 Service B

3.10 Semi-Postpay Pay Stations C

3.11 Prepay Pay Stations C

3.12 Intercept C

3.13 PBX Rotation C

4. INTEROFFICE TRUNK TESTS

4.1 Outgoing D

4.2 Incoming E

4.3 Busy Verification E

5. ALARMS

5.1 Alarm Sending and Checking F

6. POWER EQUIPMENT

6.1 Charger Voltage Settings G

6.2 Charger Noise G

6.3 Charger Inventory G

6.4 Batteries G

7. MAIN DISTRIBUTING FRAME

7.1 Main Frame H

8. SUBSCRIBER LOOP TEST FACILITY

8.1 Subscriber Loop Test Facility H

8.2 Remote Switching H

9. RINGING GENERATORS

9.1 Ringing Generators H

9.2 Output Voltage H

10. TONES AND TONE LEVELS

10.1 Tone Measurements I
Bulletin 1753E-201

Page 19

MASTER CHECKLIST

(Continued)

Paragraph Test Checklist Assigned to: Completed

11. LINE LOAD CONTROL

11.1 Priority I

12. SWITCHED ACCESS SERVICE

12.1 Feature Groups I

12.2 Equal Access I

12.3 ANI Equipment I

13. PLANT REGISTERS

13.1 Plant Registers I

14. FIRE CALL EQUIPMENT

14.1 Fire Call Equipment I

15. DRAWINGS & PRINTED MATERIAL

15.1 Quantity as required I

15.2 I/O Information I

15.3 Floor Plan Information I

16. PROCESSOR TESTS

16.1 Common Processor Equipment Transfer J

16.1.1 Automatic Transfer J

16.2 CLOCK SYNCHRONIZATION

16.2.1 Synchronization Tests J

16.3 ADMINISTRATIVE FUNCTIONS

16.3.1 Directory Service Orders J

16.3.2 Trunk Group Information J

16.3.3 Line Class of Service Information J

16.3.4 Translator Table Information J

16.3.5 Memory Reload Test J

16.3.6 System Diagnostics Tests J

16.3.7 Traffic Output J

16.3.8 Information Restored J

17. REDUNDANCY

17.1 Redundant Systems J

18. TRANSMISSION TESTS

18.1 General K

18.2 Insertion Loss K

18.3 Frequency Response K

18.4 Idle Channel Noise K

18.5 Quantizing Distortion K

19. RST UNITS

19.1 Lines L

20. ADDITIONAL TESTS

20.1 Borrower Requirements M
Bulletin 1753E-201

Page 20

CHECKLIST A

Dial from Line A to Line B through the following lines and check for proper operation (reverse

Lines A & B on a portion of lines):

RELATED

522

PART I

PAR.(S)

7.1.1

7.1.2

7.1.4

7.1.14 7.1.14 7.1.13 7.1.12 7.10.2 6.1.1 6.1.1

TEST

LINE

DIAL

TONE &

RINGS

OK

RING

BACK

RING

TRIP

ANS.

SUP.

TALKS

OK

LINE

BUSY

REORDERCALLING

PARTY 1900 

NUMBER DIALS OK TONE TONE CONTROL ORIG TERM

Notes: 1. Checkmark (3) indicates test OK for Trial #1; if Trial #2 is made, use an 'X' for test

OK.

2. Number of lines to be determined from Table 1.

3. Refer to Checklist B for additional tests.
Bulletin 1753E-201

Page 21

CHECKLIST B

During the previous tests (Checklist A), conduct the following checks on several of the lines. Use

the same indicators as before to indicate test OK.

TEST ( FORM 522, PART I REFERENCE) TEST LINE AND RESULTS

Lockout (6.4.1 & 6.4.2)

Enter Test Line Number

Activated - LO level & ROH Tone

Cleared - Automatic Reconnect

Timing Checks (19.6.2, 18.3, 18.4, 18.6 & 18.7)

Enter Test Line Number

Ring Cycle (1.25 to 2 Sec.; 4 Sec. Silent)

Lockout (20 to 30 sec.)

Partial Dial (15 to 37 sec.)

"Called Party" Disconnect (10 to 32 Secs)

Distance Dialing

Vertical Services (5.5)

Enter Test Line Number

Call Forwarding

Call Waiting

Abbreviated Dialing

3-Way Calling

Other

Nuisance Trap (7.9)

Enter Test Line Number

Held by Called Party

Printout

911 Emergency Service (5.19.1)

Enter Test Line Number

Routing verified
Bulletin 1753E-201

Page 22

CHECKLIST C

TEST ( FORM 522, PART I REFERENCE) TEST LINE AND RESULTS

Pay Station (Semi-Postpay) (6.5, 8.3.1 & 11.2.5)

Enter Test Line Number

Operator Tone

911 Emergency

Coin Deposit Before Talk (Local-Local)

Dial Tone First

Pay Station Answer w/o Coin

1+, 0+/0- handled appropriately

Operator Ringback

Coin Collect

Pay Station (Prepay) (6.5, 8.3.1 & 11.2.5)

Enter Test Line Number

Operator Tone

Coin Collect

Coin Return

911 Emergency

1+, 0+/0- handled appropriately

Dial Tone First

Pay Station Answer w/o Coin

Operator Ringback )

Intercept (7.9.2 & 7.9.3)

Enter Test Line Number

Vacant Code & Unassigned Number

Changed Number

Discontinued Number

PBX Rotation (7.3.4, 7.3.5, & 7.3.6)

Enter Test Line Number

Night Service Number

Trunk Hunts

All Lines Busy
Bulletin 1753E-201

Page 23

CHECKLIST D

Outgoing: The "translation tables" should be reviewed and considered in developing the test

calls. They should be logged and subsequently checked against the "billing" department’s records

of such calls. Access trunk groups from random subscriber lines and, as applicable, check

operator service trunks from both coin and non-coin lines.

TRUNK DP/MF RING ANS. TALKS NO IDENTIFICATION

TRUNK

TIMED

CALL

FAIL

ALL

TRUNKS

NO. SIG. OK BACK SUPV OK NOISE CLG. NO. CLD.NO. DISC. IND. (1) BUSY

Notes:

1. Enter the failure indication: such as reorder tone (RT), intercept announcement

(IA), operator (0P).
Bulletin 1753E-201

Page 24

CHECKLIST E

Incoming: Verify access codes from operators, wire chief positions and maintenance centers.

"VERIFY OK" should include monitor, bridge and split based on requirements specified.

Conduct tests with connecting company if possible; if not, access trunk circuit and dial local lines

with test devices selected. If the switching system is serving as an "AMA" location for another

system, verify that the "calling" and "called" numbers are correct and have been properly

recorded.

Applicable Form 522, Part I paragraphs are 7 (Intraoffice Switching Requirements) and 8

(Interoffice Trunk Circuit Requirements).

TRUNK DP/MF RING ANS. TALK NO INCOMING BUSY VERIFICATION

NO. SIG. BACK SUPV. OK NOISE CLG.

NO.

CLD.

NO.

OPER.

ACCESS

WIRE CH.

ACCESS

VERIF.

OK
Bulletin 1753E-201

Page 25

CHECKLIST F

Alarms: Check two or more alarms in each classification by simulating a trouble or failure in that

category. (Form 522, Part I, paragraph 15.1)

CLASSIFICATION TROUBLE

LOCAL

ALARM

INDICATION

ALARM

CHECK

PRIORITY

AUD. VIS. TONE

TRK.

REL.

OVERRIDE

LOSS OF SERVICE

CATASTROPHIC: LOSS OF RST

LOSS OF NETWORK CONTROL

LOSS OF BOTH PROCESSORS

LOSS OF SUBSCRIBER GROUP

MAJOR: LOSS OF TRUNK GROUP

GROUP FUSE

REDUNDANT EQPT. FAILURE

CHARGER FAIL (1)

CUMULATIVE LINE LOCKOUT

MINOR:

(1) Alarm delayed 15 min.
Bulletin 1753E-201

Page 26

CHECKLIST G

CHARGERS

CHARGER

VOLTAGE APPLIED

TO BATTERIES CHARGER NOISE

NUMBER LEAD ANTIMONY LEAD CALCIUM ELECTRICAL ACOUSTICAL

1

2

3

COMB.

BATTERIES

BATTERY FLOAT READINGS

CELL NO. CELL VOLTS SPECIFIC ELECTROLYTE CORRECTED READINGS

GRAVITY TEMP. LEVEL VOLTAGE SPEC. GRAVITY

 1

 2

 3

 4

 5

 6

 7

 8

 9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

ADDITIONAL BATTERY PLANT CHECKS

Instruments Container (Not

faulty or cracked)

Proper Spacing Tight Connections Top of Cell

Clearance

Explosion Control

Device (per cell)
Bulletin 1753E-201

Page 27

CHECKLIST H

Main Distributing Frame (20.)

Accepted Protectors (RUS IP 344-2)

Adequate Testing Facilities

Sufficient Protector Mountings and Arresters or

Grounding Modules

Sufficient Cable Pair Terminations

Subscriber Loop Test Facilities (15.2.3.1)

Test each function below and verify:

Bridged Foreign EMF

Line Battery

Open Circuit

Shorts

Tip Ground

Ring Ground

Tip & Ring Negative Potential

Subscriber Line Capacitance

Talk Battery to Line

Supply Talk Battery to Line w/Booster

Supply Talk Battery to Line w/o Booster

Test In to Central Office

Test Out of Central Office

Reverse Polarity for Voltage Readings

Ring Subscriber w/Test Access Circuit

Ring Subscriber w/Test Shoe

Test for Booster Battery Voltage and Polarity

through Test Shoe

Test RST from Host office

Dial Speed Test (15.2.3.4 & 15.2.3.5)

Returns proper signals to calling station

Ringing Generators (19.5.2.3)

Measure output voltage of each frequency

TAPS (Volts)

FREQUENCY (Hz) L M H MEASURED

 16 2/3 - 20 90 105 120

 21 - 30 95 110 120

 31 - 42 100 115 130

 43 - 54 110 125 140
Bulletin 1753E-201

Page 28

CHECKLIST I

Tone Levels (9.2)

Measure various call progress tone levels at switchboard end of MDF line cable.

TYPE REQUIREMENTS MEASURED

Dial Tone -10 dBm0

Low Tone -21 dBmO

High Tone -17 dBmO

Ringback Tone -16 dBmO

ROH Tone + 3 dBmO

TEST CHECKS OK

Line Load Control (7.11)

Verify line load control activation

Check that priority lines function

Check that non-priority lines cannot function.

Switched Access Service (11.)

Feature groups

Verify proper Feature Groups have been furnished

Verify appropriate carriers have been assigned

Call all assigned carriers and verify signaling sequence

and carrier identification

Verify calls from coin lines send TSPS format or are

blocked

Equal Access

Verify equal access capability

Verify that presubscribed customers do not have to dial

carrier access code

Automatic Number Identification (ANI)

Verify called numbers

Verify calling number

Verify billing information

Verify remote polling capability (if applicable)

Plant, Traffic and Separations Registers (16.4)

Verify software administration of memory counter

assignments, data collection, readout and reset functions

as specified/required.

Fire Call Equipment

Verify operation of supplier’s equipment

Other

Drawings and Instructions (24.3)

Verify required quantity

Verify 2 sets I/O material

Verify floor plan drawing
Bulletin 1753E-201

Page 29

CHECKLIST J

TEST CHECKS OK

Processor Tests (7.6.2, 14.)

Common Processor Equipment Transfer

Test calls established before transfer

Test calls made after transfer

Established calls not lost after transfer

Redundant circuits checked

Processors

Memories

Time Slot Interchanges

Clocks

Clock Synchronization (10.)

Check minimum long-term accuracy (ability to synchronize to external reference) (10.2.1 or

10.3.1)

Check minimum stability upon loss of all frequency references (10.2.2 or 10.3.2)

Check alarm thresholds ( LSSGR, Issue 2, July 1987, Section 18.3.5)

Check ability to switch to and synchronize with a secondary reference

Check for one slip or less on switched reference (BOC Notes on the LEC Networks - 1990, Issue

1, March 1991, Section 11.9.2, Table 11-2) (Stratum 3 only)

Automatic Transfer Function

Manual Transfer Function

Administrative Functions Check:

Directory Service Orders

Verify that the list of directory numbers can be printed out in numerical order.

Verify that all information regarding directory numbers can be printed out.

Enter a directory number and alter the information. Verify that the change is made.

Verify that a list of equipment "made busy"/"busied out" for maintenance can be printed out.

Trunk Group Information (14.3 and 14.4)

Verify that the trunk group numbers can be printed out in numerical order.

Enter the hunt group number of any assigned trunk hunting group and verify that the system

prints out all information for that group.

Enter a valid trunk hunt group number and delete a trunk from that group. Verify.

Add the trunk deleted above to the appropriate trunk hunt group. Verify.

Line Class of Service Information

Verify that a numerical list of all line classes of service can be printed out by the system.

Enter a valid line class of service number and verify that all the information for that number is

printed out.

Enter information necessary to create a new class of service. Verify that the system responds

appropriately.

Verify that the system deletes the class of service number created above.

Enter an existing line class of service number and modify its characteristics. Verify.

Enter a valid line class of service number and verify that the system prints out all equipment

numbers referencing that line class of service number.
Bulletin 1753E-201

Page 30

CHECKLIST J

(Continued)

TEST CHECKS OK

Translator Table Information

Verify that all applicable office (NXX) codes are printed out by the system in numerical

order.

Enter a valid NXX code and verify that all information for that code is printed out.

Enter a valid NXX code and modify the information for that code. Verify that the system

entered the changes.

Memory Reload Test

Clear the database memory. Check time necessary to reload and check accuracy of the

information.

System Diagnostics Tests

Check the major diagnostics programs following the procedures given by the manufacturer.

Printouts should be checked for proper information.

Check the traffic output on the I/0 device.

Redundant Equipment (7.6.2, 7.6.6, 14.1, 19.4.2, 19.5.1, 23.6.2, & 23.6.3)

Simulate failures in all redundant items and verify switchover or specified minimum requirements

Item Switched OK Meets Minimum

Requirements

Ringing Machines

Power Converters

Ringing Machine - Single

Power Converter - Single

CAUTION:

Care should be taken to ensure that whenever valid information is changed during these

tests it is replaced in its original form.
Bulletin 1753E-201

Page 31

CHECKLIST K

INSERTION LOSS (RUS Form 522, Part I, paragraph 17.3)

LINE OR TRUNK NUMBER

TEST

LINE TO LINE

LINE TO TRUNK

TRUNK TO TRUNK

FREQUENCY RESPONSE (RUS Form 522, Part I, paragraph 17.4)

LINE/

TRUNK

LINE TO LINE TRUNK TO TRUNK

NO. 60 Hz 300 Hz 1000 Hz 3200 Hz 60 Hz 200 Hz 300 Hz 1000 Hz 3000 Hz 3300 Hz 3400 Hz

IDLE CHANNEL NOISE (RUS Form 522, Part I, paragraph 17.10)

Measure on terminated call

LINE NUMBER TERMINATED CALL (dBrnC) 3 kHz FLAT

QUANTIZING DISTORTION (RUS Form 522, Part I, paragraph 17.13)

LINE ORIG. TERM. ORIG. TERM. ORIG. TERM. ORIG. TERM. ORIG. TERM.

NUMBER

C

MESSAGE

NOISE
Bulletin 1753E-201

Page 32

CHECKLIST L

RST ACCEPTANCE TESTS

TEST CHECKS OK

Check lines in same manner as host.

Make tests for all operational features.

Check that the RST will operate as described with link(s) disabled.

Check amount of equipment supplied and verify traffic requirement is met or exceeded.

Check chargers and batteries

Check system housing for environmental control requirements specified.
Bulletin 1753E-201

Page 33

CHECKLIST M

This checklist should be used, as appropriate, for any additional tests required by the Borrower.

TEST MEASURED CHECKS OK