'UNITED STATES DEPARTMENT OF AGRICULTURE 

Rural Utilities Service 

BULLETIN 1753B-001 (Form 522) 

RD-GD-1996-19

SUBJECT: RUS General Specification for Digital, stored Program 

Controlled Central Office Equipment 

TO: All RUS Telecommunications Borrowers 

RUS Telecommunications Staff 

EFFECTIVE DATE: January 16, 1996 

EXPIRATION DATE: Date of change of 7 CFR part 1755.522 by 

rulemaking 

OFFICE OF PRIMARY INTEREST: Central Office Equipment Branch, 

Telecommunications Standards Division 

PREVIOUS INSTRUCTIONS: This revised Bulletin 1753E-001 (Form 

522), RUS General Specification for Digital, stored Program 

Controlled Central Office Equipment, replaces Bulletin 1753E-001 

(Form 522), RUS General Specification for Digital, stored Program 

Controlled Central Office Equipment issued June 4, 1993. 

FILING INSTRUCTIONS: Discard Bulletin 1753E-001 (Form 522) dated 

June 4, 1993, and replace with this Bulletin 1753E-001. File 

with 7 CFR part 1753 and is available to RUS staff on RUSNET. 

PURPOSE: This revision removes the requirement for multiparty 

service and associated features and services. 

This bulletin is a "user friendly" reformat of the text codified 

in 7 CFR 1755.522 published at 60 FR 64311, dated December 15, 

1995. Every effort has been made to ensure the accuracy of this 

document. However, in case of discrepancies, the regulation at 7 

CFR 1755 section 1755.522 is the authorized source. 

7

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-001 (Form 522)

Page 2

January 1996

TABLE OF CONTENTS

Part I - General Specification

1. General.................................................I-1

2. Reliability.............................................I-3

3. System Type Acceptance Tests............................I-4

4. Types of Requirements...................................I-4

5. General Requirements....................................I-5

6. Line Circuit Requirements...............................I-8

6.1 General.................................................I-8

6.2 Dialing.................................................I-9

6.3 Impedance...............................................I-9

6.4 Lockout.................................................I-9

6.5 Pay Stations............................................I-9

6.6 Loop Extension.........................................I-10

6.7 Private Branch Exchange (PBX) Lines....................I-10

6.8 Quantity...............................................I-10

6.9 Types..................................................I-10

7. Intraoffice Switching Requirements.....................I-10

8. Interoffice Trunk Circuit Requirements.................I-16

8.1 General................................................I-16

8.2 Quantity...............................................I-16

8.3 Requirements for Interoffice Connections...............I-16

8.4 Requirements for Direct Digital Connections............I-17

9. Tone Requirements......................................I-18

9.1 General................................................I-18

9.2 Tone Specifications....................................I-18

10. System Clock...........................................I-19

11. Switched Access Service Arrangements...................I-20

11.1 General................................................I-20

11.2 Operation..............................................I-20

12. Fusing and Protection Requirements.....................I-21

12.1 General................................................I-21

12.2 Fuses..................................................I-21

12.3 Components.............................................I-21

13. Switching Network Requirements.........................I-22

13.1 The Network............................................I-22

13.2 Network Quantity.......................................I-22

14. Stored Program Control (SPC) Equipment Requirements....I-22
Bulletin 1753E-001 (Form 522)

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January 1996

TABLE OF CONTENTS

15. Maintenance Facilities.................................I-24

15.1 Alarm Features, Including Alarm Sending................I-24

15.2 Trouble Location and Test..............................I-26

15.3 Transmission Testing...................................I-28

16. Traffic................................................I-30

16.1 General Engineering Guidelines.........................I-30

16.2 Grade of Service.......................................I-34

16.3 Holding Times..........................................I-35

16.4 Traffic Data Requirements..............................I-37

17. Transmission...........................................I-38

17.1 General................................................I-38

17.2 Impedance..............................................I-38

17.3 Insertion Loss.........................................I-38

17.4 Frequency Response.....................................I-39

17.5 Overload Level.........................................I-39

17.6 Gain Tracking (Linearity)..............................I-39

17.7 Return Loss............................................I-40

17.8 Longitudinal Balance...................................I-40

17.9 60 Hz Longitudinal Current Immunity....................I-41

17.10 Steady Noise...........................................I-41

17.11 Impulse Noise..........................................I-41

17.12 Crosstalk Coupling.....................................I-41

17.13 Quantizing Distortion..................................I-41

17.14 Absolute Delay.........................................I-41

17.15 Envelope Delay Distortion..............................I-42

17.16 Digital Error Rate.....................................I-42

17.17 Battery Noise..........................................I-42

17.18 Radio and Television Interference......................I-42

18. Timing Intervals.......................................I-42

18.1 Type of Equipment Required.............................I-42

18.2 Tolerance..............................................I-42

18.3 Permanent Signal Timing................................I-42

18.4 Partial Dial Timing....................................I-42

18.5 Charge Delay Timing....................................I-42

18.6 Called Party Disconnect Timing.........................I-43

18.7 Timing Intervals for Signals Involved

 in Distance Dialing................................I-43

19. Power Requirements and Equipment.......................I-43

19.1 Operating Voltage......................................I-43

19.2 Batteries..............................................I-43

19.3 Charging Equipment.....................................I-44

19.4 Miscellaneous Voltage Supplies.........................I-45

19.5 Ringing Generators.....................................I-46

19.6 Interrupter Equipment..................................I-48

19.7 Power Panels...........................................I-48

20. Main Distributing Frames...............................I-49
Bulletin 1753E-001 (Form 522)

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January 1996

TABLE OF CONTENTS

21. Electrical Protection..................................I-50

21.1 Surge Protection.......................................I-50

21.2 Extraordinary Surge Protection.........................I-52

21.3 Dielectric Strength....................................I-52

21.4 Insulation Resistance..................................I-53

21.5 Self-protection........................................I-53

21.6 Static Discharge.......................................I-53

22. Miscellaneous..........................................I-53

22.1 Office Wire............................................I-53

22.2 Wire Wrapped Terminals.................................I-53

22.3 Protection Against Corrosion...........................I-54

22.4 Screws and Bolts.......................................I-54

22.5 Temperature and Humidity Range.........................I-54

22.6 Stenciling.............................................I-54

22.7 Equipment Frame Design.................................I-54

22.8 Quantity of Equipment Bays.............................I-54

23. Remote Switching Terminal (RST)........................I-55

23.1 General................................................I-55

23.2 Span Line..............................................I-55

23.3 Switching..............................................I-55

23.4 Subscriber Line Test...................................I-55

23.5 Housing................................................I-56

23.6 Power..................................................I-56

23.7 Alarm..................................................I-57

24. Responsibilities of the Bidder.........................I-57

24.1 Central Office Layout..................................I-57

24.2 Shipment of Main Distributing Frame (MDF)..............I-57

24.3 Drawings and Printed Material..........................I-58

24.4 Distributing Frame Wire................................I-59

24.5 Technical Assistance Service...........................I-59

24.6 Spare Parts............................................I-59

24.7 Environmental Requirements.............................I-61

24.8 Unit Costs for Cost Separation Purposes................I-61

24.9 Single-point Grounding System Acceptance...............I-62

FIGURES

Figure 1 - Measuring the Effects of Low Frequency Induction..I-63

Figure 2 - Charger Noise Test................................I-64

Figure 3 - Summary of Electrical Requirements and Tests......I-65

Figure 4 - Explanation of Surge Waveshape....................I-66

Figure 5 - Current Surge Test................................I-67

Figure 6 - 60 Hz Current Surge Test..........................I-68

Figure 7 - Explanation of Arrester Response Delay Time.......I-69
Bulletin 1753E-001 (Form 522)

Page 5

January 1996

TABLE OF CONTENTS

Part II - Installation

1. Installation...........................................II-1

1.1 Responsibilities of Owner..............................II-1

1.2 Responsibilities of Bidder.............................II-2

1.3 Installation Requirements..............................II-4

1.4 Operational Test Requirements..........................II-4

1.5 Grounding System Audit.................................II-5

Part III - Specification for Digital, Stored Program Controlled

Central Office Equipment Detailed Requirements (Host)

1. General................................................III-1

2. Numbering Scheme.......................................III-2

3. Office Clock...........................................III-4

4. Interoffice Trunking Diagram...........................III-4

5. Translator Function Chart..............................III-5

6. Line Circuit Requirements..............................III-6

6.1 Types of Lines.........................................III-6

6.2 Data on Lines Requiring Range Extension................III-7

7. Traffic Data - Line Originating and

 Terminating Traffic...............................III-9

8. Trunk Circuit Requirements............................III-11

8.1 Interoffice Trunking..................................III-11

8.2 Switched Traffic Data.................................III-12

9. Checklist of Features Required........................III-13

9.1 Alternate Routing.....................................III-13

9.2 Data Service..........................................III-13

9.3 Office Type...........................................III-13

9.4 Billing Data..........................................III-14

9.5 Pollable Systems......................................III-14

9.6 AMA Format............................................III-14

10. Miscellaneous Operating Features......................III-15

10.1 Busy Verification.....................................III-15

10.2 Revertive Calls - Directory Number Only...............III-15

10.3 Intercept Facilities..................................III-15

10.4 Line Load Control.....................................III-16

10.5 Service Observing Facilities..........................III-16

10.6 Hotel-Motel Arrangements..............................III-16

10.7 Nailed Up Connections.................................III-17

10.8 Vertical Services.....................................III-17
Bulletin 1753E-001 (Form 522)

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January 1996

TABLE OF CONTENTS

11. Maintenance Facility Requirements.....................III 17

11.1 Alarm Signals.........................................III 17

11.2 Trouble Location and Test.............................III 18

11.3 Transmission Tests....................................III-19

11.4 Line Testing..........................................III-19

11.5 Remote Control........................................III-19

12. Power Equipment Requirements..........................III-20

12.1 Central Office Battery................................III-20

12.2 Charging Equipment....................................III-21

12.3 Ringing Equipment.....................................III-21

12.4 Power Board...........................................III-22

13. Distributing Frame Requirements.......................III-22

14. Building and Floor Plan Information...................III-23

15. Alternate Requests....................................III-25

16. Explanatory Notes.....................................III-26

Part IV -Detailed Information on Remote Switching Terminals

(RST's)

1. Number of Subscriber Lines..............................IV-1

2. Traffic.................................................IV-1

3. Subscriber Loop Resistance..............................IV-1

4. Range Extension.........................................IV-2

5. Power Supply............................................IV-2

6. Emergency Operation.....................................IV-3

7. RST Distribution Frame Requirements.....................IV-3

8. Building and Floor Plan Information.....................IV-5

9. Subscriber Line Test....................................IV-5

10. Span Lines to Host Central Office.......................IV-5

11. Grounding Considerations................................IV-5

12. Explanatory Notes.......................................IV-6

Part V - Specifications for Digital, Stored Program Controlled

Central Office Equipment Detailed Requirements - Bidder Supplied

Information

1. General..................................................V-1

2. Performance Objectives...................................V-2

2.1 Reliability..............................................V-2

2.2 Busy Hour Load Capacity and Traffic Delay................V-2

3. Equipment Quantities Dependent on System Design..........V-2

3.1 Switch Frames and Circuits...............................V-2

4. RST.......................................................V-3
Bulletin 1753E-001 (Form 522)

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January 1996

TABLE OF CONTENTS

5. Power....................................................V-4

5.1 AC Power Drain Watts.....................................V-4

5.2 Heat Dissipation Watts...................................V-4

6. Additional Information to be Furnished by Bidder.........V-4

7. Explanatory Notes........................................V-5

Part VI - Acceptance Checklist - Single-point Grounding System

1. Approval Statement......................................VI-1

2. General Survey..........................................VI-2

3. Master Ground Bar (MGB).................................VI-6

4. Ground Window Bar (GWB).................................VI-8

5. Isolated Ground Zone (IGZ)..............................VI-9

6. Entrance and Tip Cables................................VI-10

7. Cable Entrance Ground Bar (CEGB).......................VI-11

8. Main Distributing Frame (MDF)..........................VI-13

9. Power Service Protection and Grounding.................VI-16

10. Miscellaneous..........................................VI-17

INDEX:

 Specifications, Digital Central Office Equipment

ABBREVIATIONS

4HW 4-high Consecutive Week

AC or ac Alternating Current

AMA Automatic Message Accounting

ANC All Number Calling

ANI Automatic Number Identification

ANSI American National Standards Institute

ASTM American Society for Testing Materials

AWG American Wire Gauge

CAROT Centralized Automatic Reporting on Trunks

CCS Centum (hundred) Call Seconds

CEGB Cable Entrance Ground Bar

CFR Code of Federal Regulations

COE Central Office Equipment

dB Decibel

dBm0 Decibel Metallic Referenced to Zero

dBrnC Decibels above Reference Noise, C-message Weighted

dc Direct Current

DDD Direct Distance Dialing

DP Dial Pulse

EMF Electromotive Force

ERL Echo Return Loss
Bulletin 1753E-001 (Form 522)

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January 1996

ABBREVIATIONS (Continued)

ESS Electronic Switching System

GWB Ground Window Bar

Hz Hertz

IEEE Institute of Electrical and Electronic Engineers

IGZ Isolated Ground Zone

LAMA Local Automatic Message Accounting

LSSGR LATA Switching Systems Generic Requirements

MDF Main Distributing Frame

MF Multifrequency

MGB Master Ground Bar

PBX Private Branch Exchange

PC Printed Circuit

PCM Pulse Code Modulation

PPS Pulses per Second

rms Root Mean Square

ROH Receiver Off-Hook

RST Remote Switching Terminal

RUS Rural Utilities Service

SDN Subscriber Directory Number

SPC Stored Program Control

SRL Singing Return Loss

SxS Step-by-Step

TE&CM Telecommunications Engineering and Construction Manual

VF Voice Frequency

°C Degree Centigrade

°F Degree Fahrenheit
Bulletin 1753E-001(522)

Page 9

January 1996

BULLETIN TO CFR PARAGRAPH NUMBER CROSS-REFERENCE

PART I GENERAL SPECIFICATION

1753E-001 1755.522

1. (a)

1.1 (a)(1)

1.2 (a)(2)

1.3 (a)(3)

1.4 (a)(4)

1.5 (a)(5)

1.6 (a)(6)

1.7 (a)(7)

1.8 (a)(8)

1.9 (a)(9)

1.10 (a)(10)

1.11 (a)(11)

1.12 (a)(12)

2. (b)

2.1 (b)(1)

2.2 (b)(2)

2.3 (b)(3)

3. (c)

3.1 (c)(1)

3.2 (c)(2)

3.3 (c)(3)

4. (d)

4.1 (d)(1)

4.2 (d)(2)

4.3 (d)(3)

4.4 (d)(4)

4.5 (d)(5)

5. (e)

5.1 (e)(1)

5.2 (e)(2)

5.3 (e)(3)

5.4 (e)(4)

5.5 (e)(5)

5.6 (e)(6)

5.7 (e)(7)

5.8 (e)(8)

5.9 (e)(9)

5.10 (e)(10)

5.11 (e)(11)

5.12 (e)(12)

5.13 (e)(13)

5.14 (e)(14)

1753E-001 1755.522

5.15 (e)(15)

5.16 (e)(16)

5.17 (e)(17)

5.18 (e)(18)

5.19 (e)(19)

5.19.1 (e)(19)(i)

5.19.2 (e)(19)(ii)

5.19.3 (e)(19)(iii)

5.19.4 (e)(19)(iv)

5.19.5 (e)(19)(v)

5.19.6 (e)(19)(vi)

5.19.7 (e)(19)(vii)

5.19.8 (e)(19)(viii)

5.19.9 (e)(19)(ix)

6. (f)

6.1 (f)(1)

6.1.1 (f)(1)(i)

6.1.2 (f)(1)(ii)

6.1.3 (f)(1)(iii)

6.2 (f)(2)

6.2.1 (f)(2)(i)

6.2.2 (f)(2)(ii)

6.2.3 (f)(2)(iii)

6.3 (f)(3)

6.4 (f)(4)

6.4.1 (f)(4)(i)

6.4.2 (f)(4)(ii)

6.5 (f)(5)

6.6 (f)(6)

6.6.1 (f)(6)(i)

6.6.2 (f)(6)(ii)

6.6.3 (f)(6)(iii)

6.7 (f)(7)

6.8 (f)(8)

6.9 (f)(9)

7. (g)

7.1 (g)(1)

7.1.1 (g)(1)(i)

7.1.2 (g)(1)(ii)

7.1.3 (g)(1)(iii)

7.1.4 (g)(1)(iv)

7.1.5 (g)(1)(v)

7.1.6 (g)(1)(vi)
Bulletin 1753E-001(522)

Page 10

January 1996

1753E-001 1755.522

7.1.7 (g)(1)(vii)

7.1.8 (g)(1)(viii)

7.1.9 (g)(1)(ix)

7.1.10 (g)(1)(x)

7.1.11 (g)(1)(xi)

7.1.12 (g)(1)(xii)

7.1.13 (g)(1)(xiii)

7.1.14 (g)(1)(xiv)

7.1.15 (g)(1)(xv)

7.2 (g)(2)

7.2.1 (g)(2)(i)

7.2.2 (g)(2)(ii)

7.2.3 (g)(2)(iii)

7.2.4 (g)(2)(iv)

7.2.5 (g)(2)(v)

7.2.6 (g)(2)(vi)

7.2.7 (g)(2)(vii)

7.2.8 (g)(2)(viii)

7.2.9 (g)(2)(ix)

7.2.10 (g)(2)(x)

7.2.11 (g)(2)(xi)

7.2.12 (g)(2)(xii)

7.2.13 (g)(2)(xiii)

7.3 (g)(3)

7.3.1 (g)(3)(i)

7.3.2 (g)(3)(ii)

7.3.3 (g)(3)(iii)

7.3.4 (g)(3)(iv)

7.3.5 (g)(3)(v)

7.3.6 (g)(3)(vi)

7.4 (g)(4)

7.5 (g)(5)

7.5.1 (g)(5)(i)

7.5.2 (g)(5)(ii)

7.5.3 (g)(5)(iii)

7.5.4 (g)(5)(iv)

7.6 (g)(6)

7.6.1 (g)(6)(i)

7.6.2 (g)(6)(ii)

7.6.3 (g)(6)(iii)

7.6.4 (g)(6)(iv)

7.6.5 (g)(6)(v)

7.6.6 (g)(6)(vi)

7.7 (g)(7)

7.7.1 (g)(7)(i)

7.7.2 (g)(7)(ii)

7.7.3 (g)(7)(iii)

7.7.4 (g)(7)(iv)

7.8 (g)(8)

1753E-001 1755.522

7.8.1 (g)(8)(i)

7.8.2 (g)(8)(ii)

7.9 (g)(9)

7.9.1 (g)(9)(i)

7.9.2 (g)(9)(ii)

7.9.3 (g)(9)(iii)

7.9.4 (g)(9)(iv)

7.9.5 (g)(9)(v)

7.10 (g)(10)

7.11 (g)(11)

7.11.1 (g)(11)(i)

7.11.2 (g)(11)(ii)

7.11.3 (g)(12)

8. (h)

8.1 (h)(1)

8.1.1 (h)(1)(i)

8.1.2 (h)(1)(ii)

8.1.3 (h)(1)(iii)

8.1.4 (h)(1)(iv)

8.2 (h)(2)

8.3 (h)(3)

8.3.1 (h)(3)(i)

8.3.2 (h)(3)(ii)

8.3.3 (h)(3)(iii)

8.3.4 (h)(3)(iv)

8.3.5 (h)(3)(v)

8.3.6 (h)(3)(vi)

8.3.7 (h)(3)(vii)

8.3.8 (h)(3)(viii)

8.4 (h)(4)

8.4.1 (h)(4)(i)

8.4.2 (h)(4)(ii)

8.4.3 (h)(4)(iii)

9. (i)

9.1 (i)(1)

9.2 (i)(2)

9.2.1 (i)(2)(i)

9.2.2 (i)(2)(ii)

9.2.3 (i)(2)(iii)

9.2.4 (i)(2)(iv)

9.2.5 (i)(2)(v)

9.2.6 (i)(2)(vi)

9.2.7 (i)(2)(vii)

9.2.8 (i)(2)(viii)

9.2.9 (i)(2)(ix)

9.2.10 (i)(2)(x)
Bulletin 1753E-001(522)

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January 1996

1753E-001 1755.522

9.2.11 (i)(2)(xi)

9.2.12 (i)(2)(xii)

10. (j)

10.1 (j)(1)

10.2 (j)(2)

10.2.1 (j)(2)(i)

10.2.2 (j)(2)(ii)

10.2.3 (j)(2)(iii)

10.3 (j)(3)

10.3.1 (j)(3)(i)

10.3.2 (j)(3)(ii)

10.3.3 (j)(3)(iii)

11. (k)

11.1 (k)(1)

11.2 (k)(2)

11.2.1 (k)(2)(i)

11.2.2 (k)(2)(ii)

11.2.3 (k)(2)(iii)

11.2.4 (k)(2)(iv)

11.2.5 (k)(2)(v)

11.2.6 (k)(2)(vi)

11.2.7 (k)(2)(vii)

11.2.8 (k)(2)(viii)

12. (l)

12.1 (l)(1)

12.1.1 (l)(1)(i)

12.1.2 (l)(1)(ii)

12.2 (l)(2)

12.3 (l)(3)

12.3.1 (l)(3)(i)

12.3.2 (l)(3)(ii)

12.3.3 (l)(3)(iii)

13. (m)

13.1 (m)(1)

13.1.1 (m)(1)(i)

13.1.2 (m)(1)(ii)

13.1.3 (m)(1)(iii)

13.2 (m)(2)

14. (n)

14.1 (n)(1)

14.2 (n)(2)

14.3 (n)(3)

14.4 (n)(4)

14.4.1 (n)(4)(i)

14.4.2 (n)(4)(ii)

14.4.3 (n)(4)(iii)

1753E-001 1755.522

14.4.4 (n)(4)(iv)

14.4.5 (n)(4)(v)

14.4.6 (n)(4)(vi)

14.4.7 (n)(4)(vii)

14.4.8 (n)(4)(viii)

14.5 (n)(5)

14.6 (n)(6)

14.7 (n)(7)

15. (o)

15.1 (o)(1)

15.1.1 (o)(1)(i)

15.1.2 (o)(1)(ii)

15.1.2.1 (o)(1)(ii)(A)

15.1.2.2 (o)(1)(ii)(B)

15.1.2.3 (o)(1)(ii)(C)

15.1.3 (o)(1)(iii)

15.1.4 (o)(1)(iv)

15.1.5 (o)(1)(v)

15.1.6 (o)(1)(vi)

15.1.7 (o)(1)(vii)

15.1.8 (o)(1)(viii)

15.1.9 (o)(1)(ix)

15.1.10 (o)(1)(x)

15.1.10.1 (o)(1)(x)(A)

15.1.10.2 (o)(1)(x)(B)

15.1.10.3 (o)(1)(x)(C)

15.1.10.4 (o)(1)(x)(D)

15.1.11 (o)(1)(xi)

15.1.12 (o)(1)(xii)

15.2 (o)(2)

15.2.1 (o)(2)(i)

15.2.1.1 (o)(2)(i)(A)

15.2.1.2 (o)(2)(i)(B)

15.2.2 (o)(2)(ii)

15.2.2.1 (o)(2)(ii)(A)

15.2.2.2 (o)(2)(ii)(B)

15.2.2.3 (o)(2)(ii)(C)

15.2.2.4 (o)(2)(ii)(D)

15.2.2.5 (o)(2)(ii)(E)

15.2.2.6 (o)(2)(ii)(F)

15.2.3 (o)(2)(iii)

15.2.3.1 (o)(2)(iii)(A)

15.2.3.1.1 (o)(2)(iii)(A)(1)

15.2.3.1.2 (o)(2)(iii)(A)(2)

15.2.3.1.3 (o)(2)(iii)(A)(3)

15.2.3.1.4 (o)(2)(iii)(A)(4)

15.2.3.1.5 (o)(2)(iii)(A)(5)

15.2.3.1.6 (o)(2)(iii)(A)(6)

15.2.3.1.7 (o)(2)(iii)(A)(7)

15.2.3.1.8 (o)(2)(iii)(A)(8)
Bulletin 1753E-001(522)

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January 1996

1753E-001 1755.522

15.2.3.1.9 (o)(2)(iii)(A)(9)

15.2.3.1.10 (o)(2)(iii)(A)(10)

15.2.3.2 (o)(2)(iii)(B)

15.2.3.3 (o)(2)(iii)(C)

15.2.3.4 (o)(2)(iii)(D)

15.2.3.5 (o)(2)(iii)(E)

15.2.3.6 (o)(2)(iii)(F)

15.3 (o)(3)

15.3.1 (o)(3)(i)

15.3.2 (o)(3)(ii)

15.3.3 (o)(3)(iii)

15.3.4 (o)(3)(iv)

15.3.5 (o)(3)(v)

15.3.6 (o)(3)(vi)

15.3.7 (o)(3)(vii)

16. (p)

16.1 (p)(1)

16.1.1 (p)(1)(i)

16.1.2 (p)(1)(ii)

16.1.3 (p)(1)(iii)

16.1.4 (p)(1)(iv)

16.1.5 (p)(1)(v)

16.1.6 (p)(1)(vi)

16.1.7 (p)(1)(vii)

16.2 (p)(2)

16.2.1 (p)(2)(i)

16.2.2 (p)(2)(ii)

16.2.3 (p)(2)(iii)

16.2.4 (p)(2)(iv)

16.2.5 (p)(2)(v)

16.2.5.1 (p)(2)(v)(A)

16.2.5.2 (p)(2)(v)(B)

16.2.5.3 (p)(2)(v)(C)

16.2.6 (p)(2)(vi)

16.2.6.1 (p)(2)(vi)(A)

16.2.6.2 (p)(2)(vi)(B)

16.2.6.3 (p)(2)(vi)(C)

16.2.6.4 (p)(2)(vi)(D)

16.2.7 (p)(2)(vii)

16.3 (p)(3)

16.3.1 (p)(3)(i)

16.3.2 (p)(3)(ii)

16.3.3 (p)(3)(iii)

16.3.4 (p)(3)(iv)

16.4 (p)(4)

16.4.1 (p)(4)(i)

16.4.1.1 (p)(4)(i)(A)

16.4.1.2 (p)(4)(i)(B)

16.4.1.3 (p)(4)(i)(C)

1753E-001 1755.522

16.4.1.4 (p)(4)(i)(D)

16.4.1.5 (p)(4)(i)(E)

16.4.2 (p)(4)(ii)

16.4.3 (p)(4)(iii)

16.4.4 (p)(4)(iv)

17. (q)

17.1 (q)(1)

17.2 (q)(2)

17.3 (q)(3)

17.3.1 (q)(3)(i)

17.3.2 (q)(3)(ii)

17.3.3 (q)(3)(iii)

17.3.4 (q)(3)(iv)

17.4 (q)(4)

17.4.1 (q)(4)(i)

17.4.2 (q)(4)(ii)

17.4.3 (q)(4)(iii)

17.5 (q)(5)

17.6 (q)(6)

17.7 (q)(7)

17.7.1 (q)(7)(i)

17.7.2 (q)(7)(ii)

17.7.2.1 (q)(7)(ii)(A)

17.7.2.2 (q)(7)(ii)(B)

17.7.2.3 (q)(7)(ii)(C)

17.7.2.4 (q)(7)(ii)(D)

17.7.2.5 (q)(7)(ii)(E)

17.7.3 (q)(7)(iii)

17.7.4 (q)(7)(iv)

17.7.5 (q)(7)(v)

17.8 (q)(8)

17.9 (q)(9)

17.10 (q)(10)

17.11 (q)(11)

17.12 (q)(12)

17.13 (q)(13)

17.13.1 (q)(13)(i)

17.13.2 (q)(13)(ii)

17.14 (q)(14)

17.15 (q)(15)

17.16 (q)(16)

17.17 (q)(17)

17.18 (q)(18)

18. (r)

18.1 (r)(1)

18.2 (r)(2)

18.3 (r)(3)

18.4 (r)(4)

18.5 (r)(5)
Bulletin 1753E-001(522)

Page 13

January 1996

1753E-001 1755.522

18.6 (r)(6)

18.7 (r)(7)

18.7.1 (r)(7)(i)

18.7.2 (r)(7)(ii)

18.7.3 (r)(7)(iii)

18.7.4 (r)(7)(iv)

18.7.5 (r)(7)(v)

18.7.6 (r)(7)(vi)

18.7.7 (r)(7)(vii)

19. (s)

19.1 (s)(1)

19.2 (s)(2)

19.2.1 (s)(2)(i)

19.2.2 (s)(2)(ii)

19.2.3 (s)(2)(iii)

19.2.4 (s)(2)(iv)

19.2.5 (s)(2)(v)

19.2.6 (s)(2)(vi)

19.2.7 (s)(2)(vii)

19.2.8 (s)(2)(viii)

19.3 (s)(3)

19.3.1 (s)(3)(i)

19.3.2 (s)(3)(ii)

19.3.3 (s)(3)(iii)

19.3.4 (s)(3)(iv)

19.3.5 (s)(3)(v)

19.3.6 (s)(3)(vi)

19.3.7 (s)(3)(vii)

19.3.8 (s)(3)(viii)

19.3.8.1 (s)(3)(viii)(A)

19.3.8.2 (s)(3)(viii)(B)

19.4 (s)(4)

19.4.1 (s)(4)(i)

19.4.2 (s)(4)(ii)

19.4.2.1 (s)(4)(ii)(A)

19.4.2.2 (s)(4)(ii)(B)

19.4.2.3 (s)(4)(ii)(C)

19.4.2.4 (s)(4)(ii)(D)

19.5 (s)(5)

19.5.1 (s)(5)(i)

19.5.1.1 (s)(5)(i)(A)

19.5.1.2 (s)(5)(i)(B)

19.5.1.2.1 (s)(5)(i)(B)(1)

19.5.1.2.2 (s)(5)(i)(B)(2)

19.5.2 (s)(5)(ii)

19.5.2.1 (s)(5)(ii)(A)

19.5.2.2 (s)(5)(ii)(B)

19.5.2.3 (s)(5)(ii)(C)

19.5.2.4 (s)(5)(ii)(D)

1753E-001 1755.522

19.5.3 (s)(5)(iii)

19.5.3.1 (s)(5)(iii)(A)

19.5.3.2 (s)(5)(iii)(B)

19.5.3.3 (s)(5)(iii)(C)

19.5.4 (s)(5)(iv)

19.5.5 (s)(5)(v)

19.5.6 (s)(5)(vi)

19.6 (s)(6)

19.6.1 (s)(6)(i)

19.6.2 (s)(6)(ii)

19.7 (s)(7)

19.7.1 (s)(7)(i)

19.7.2 (s)(7)(ii)

19.7.3 (s)(7)(iii)

19.7.4 (s)((7)iv)

20. (t)

20.1 (t)(1)

20.2 (t)(2)

20.3 (t)(3)

20.4 (t)(4)

20.5 (t)(5)

20.6 (t)(6)

20.7 (t)(7)

20.8 (t)(8)

20.9 (t)(9)

20.10 (t)(10)

20.11 (t)(11)

21. (u)

21.1 (u)(1)

21.1.1 (u)(1)(i)

21.1.2 (u)(1)(ii)

21.1.3 (u)(1)(iii)

21.1.3.1 (u)(1)(iii)(A)

21.1.3.2 (u)(1)(iii)(B)

21.1.3.3 (u)(1)(iii)(C)

21.1.3.4 (u)(1)(iii)(D)

21.1.3.5 (u)(1)(iii)(E)

21.1.4 (u)(1)(iv)

21.1.4.1 (u)(1)(iv)(A)

21.1.4.2 (u)(1)(iv)(B)

21.1.4.3 (u)(1)(iv)(C)

21.1.4.4 (u)(1)(iv)(D)

21.1.4.5 (u)(1)(iv)(E)

21.1.5 (u)(1)(v)

21.1.5.1 (u)(1)(v)(A)

21.1.5.2 (u)(1)(v)(B)

21.1.5.3 (u)(1)(v)(C)

21.1.5.4 (u)(1)(v)(D)
Bulletin 1753E-001(522)

Page 14

January 1996

1753E-001 1755.522

21.2 (u)(2)

21.3 (u)(3)

21.4 (u)(4)

21.5 (u)(5)

21.5.1 (u)(5)(i)

21.5.2 (u)(5)(ii)

21.6 (u)(6)

22. (v)

22.1 (v)(1)

22.2 (v)(2)

22.2.1 (v)(2)(i)

22.2.2 (v)(2)(ii)

22.2.3 (v)(2)(iii)

22.2.4 (v)(2)(iv)

22.3 (v)(3)

22.4 (v)(4)

22.5 (v)(5)

22.6 (v)(6)

22.7 (v)(7)

22.8 (v)(8)

23. (w)

23.1 (w)(1)

23.2 (w)(2)

23.3 (w)(3)

23.3.1 (w)(3)(i)

23.3.2 (w)(3)(ii)

23.3.3 (w)(3)(iii)

23.4 (w)(4)

23.4.1 (w)(4)(i)

23.4.2 (w)(4)(ii)

23.5 (w)(5)

23.6 (w)(6)

23.6.1 (w)(6)(i)

23.6.2 (w)(6)(ii)

23.6.2.1 (w)(6)(ii)(A)

23.6.2.2 (w)(6)(ii)(B)

23.6.2.2.1 (w)(6)(ii)(B)(1)

23.6.2.2.2 (w)(6)(ii)(B)(2)

23.6.3 (w)(6)(iii)

23.6.3.1 (w)(6)(iii)(A)

23.6.3.2 (w)(6)(iii)(B)

23.6.3.2.1 (w)(6)(iii)(B)(1)

23.6.3.2.2 (w)(6)(iii)(B)(2)

23.6.3.2.3 (w)(6)(iii)(B)(3)

23.6.3.2.4 (w)(6)(iii)(B)(4)

23.7 (w)(7)

1753E-001 1755.522

24. (x)

24.1 (x)(1)

24.1.1 (x)(1)(i)

24.1.2 (x)(1)(ii)

24.1.3 (x)(1)(iii)

24.2 (x)(2)

24.3 (x)(3)

24.3.1 (x)(3)(i)

24.3.1.1 (x)(3)(i)(A)

24.3.1.2 (x)(3)(i)(B)

24.3.1.3 (x)(3)(i)(C)

24.3.1.4 (x)(3)(i)(D)

24.3.1.5 (x)(3)(i)(E)

24.3.1.6 (x)(3)(i)(F)

24.3.1.7 (x)(3)(i)(G)

24.3.1.8 (x)(3)(i)(H)

24.3.1.9 (x)(3)(i)(I)

24.3.2 (x)(3)(ii)

24.3.2.1 (x)(3)(ii)(A)

24.3.2.2 (x)(3)(ii)(B)

24.3.2.3 (x)(3)(ii)(C)

24.3.2.4 (x)(3)(ii)(D)

24.3.2.5 (x)(3)(ii)(E)

24.3.2.6 (x)(3)(ii)(F)

24.3.2.7 (x)(3)(ii)(G)

24.3.2.8 (x)(3)(ii)(H)

24.3.2.9 (x)(3)(ii)(I)

24.3.2.10 (x)(3)(ii)(J)

24.4 (x)(4)

24.5 (x)(5)

24.6 (x)(6)

24.6.1 (x)(6)(i)

24.6.1.1 (x)(6)(i)(A)

24.6.1.2 (x)(6)(i)(B)

24.6.1.3 (x)(6)(i)(C)

24.6.1.4 (x)(6)(i)(D)

24.6.1.5 (x)(6)(i)(E)

24.6.1.6 (x)(6)(i)(F)

24.6.1.7 (x)(6)(i)(G)

24.6.2 (x)(6)(ii)

24.6.3 (x)(6)(iii)

24.6.4 (x)(6)(iv)

24.6.5 (x)(6)(v)

24.6.6 (x)(6)(vi)

24.6.7 (x)(6)(vii)

24.7 (x)(7)

24.8 (x)(8)

24.9 (x)(9)
Bulletin 1753E-001(522)

Page 15

January 1996

BULLETIN TO CFR PARAGRAPH NUMBER CROSS-REFERENCE

PART II INSTALLATION

1753E-001 1755.522

1. (y)

1.1 (y)(1)

1.1.1 (y)(1)(i)

1.1.2 (y)(1)(ii)

1.1.3 (y)(1)(iii)

1.1.4 (y)(1)(iv)

1.1.5 (y)(1)(v)

1.1.6 (y)(1)(vi)

1.1.7 (y)(1)(vii)

1.1.8 (y)(1)(viii)

1.1.9 (y)(1)(ix)

1.1.10 (y)(1)(x)

1.1.11 (y)(1)(xi)

1.1.12 (y)(1)(xii)

1.1.13 (y)(1)(xiii)

1.1.14 (y)(1)(xiv)

1.2 (y)(2)

1.2.1 (y)(2)(i)

1.2.2 (y)(2)(ii)

1.2.3 (y)(2)(iii)

1.2.4 (y)(2)(iv)

1.2.5 (y)(2)(v)

1.2.6 (y)(2)(vi)

1.2.7 (y)(2)(vii)

1.2.8 (y)(2)(viii)

1.2.9 (y)(2)(ix)

1.2.10 (y)(2)(x)

1.2.11 (y)(2)(xi)

1753E-001 1755.522

1.2.12 (y)(2)(xii)

1.2.13 (y)(2)(xiii)

1.2.14 (y)(2)(xiv)

1.2.15 (y)(2)(xv)

1.2.16 (y)(2)(xvi)

1.2.17 (y)(2)(xvii)

1.2.18 (y)(2)(xviii)

1.3 (y)(3)

1.3.1 (y)(3)(i)

1.3.2 (y)(3)(ii)

1.3.3 (y)(3)(iii)

1.3.3.1 (y)(3)(iii)(A)

1.3.3.2 (y)(3)(iii)(B)

1.3.3.3 (y)(3)(iii)(C)

1.3.3.4 (y)(3)(iii)(D)

1.4 (y)(4)

1.4.1 (y)(4)(i)

1.4.2 (y)(4)(ii)

1.4.3 (y)(4)(iii)

1.5 (y)(5)

1.5.1 (y)(5)(i)

1.5.2 (y)(5)(ii)

1.5.3 (y)(5)(iii)

1.5.4 (y)(5)(iv)

1.5.5 (y)(5)(v)

1.5.6 (y)(5)(vi)

1.5.7 (y)(5)(vii)

Parts III through VI of Bulletin 1753E-001 and Appendices A

through D of 7 CFR 1755.522 are numbered identically.

Bulletin 1753E-001 (Form 522)

Page I-1

Part I, January 1996

PART I

GENERAL SPECIFICATION

1. GENERAL

1.1 This bulletin covers general requirements for a digital

telephone central office switching system, which is fully

electronic and controlled by stored program processors. A

digital switching system transfers information which is digitally

encoded from any input port to a temporarily addressed exit port.

The information may enter the system in either analog or digital

form and may or may not be converted to analog at the exit port

depending on the facility beyond. The switching system shall

operate properly as an integral part of the telephone network

when connected to physical and carrier derived circuits meeting

RUS specifications and other generally accepted

telecommunications practices.

1.2 The output of a digital-to-digital port shall be Pulse Code

Modulation (PCM), encoded in eight-bit words using the mu-255

encoding law and D3 encoding format, and arranged to interface

with a T1 span line.

1.3 American National Standards Institute (ANSI) Standard S1.4-

1983, Specification for Sound Level Meters, is incorporated by

reference by RUS. This includes S1.4A-1985 that is also

incorporated by reference. This incorporation by reference was

approved by the Director of the Federal Register in accordance

with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained

from ANSI Inc., 11 West 42nd Street, 13th Floor, New York, NY

10036, telephone 212-642-4900. Copies may be inspected during

normal business hours at RUS, room 2838-S, U. S. Department of

Agriculture, Washington, DC 20250 or at the Office of the Federal

Register, 800 N. Capitol Street NW., Suite 700, Washington, DC

20001.

1.4 American Society for Testing Materials (ASTM) Specification

B 33-91, Standard Specification for Tinned Soft or Annealed

Copper Wire for Electrical Purposes, is incorporated by reference

by RUS. This incorporation by reference was approved by the

Director of the Federal Register in accordance with 5 U.S.C.

552(a) and 1 CFR part 51. Copies may be obtained from ASTM, 1916

Race Street, Philadelphia, PA, telephone 215-299-5400. Copies

may be inspected during normal business hours at RUS, room 2838-

S, U. S. Department of Agriculture, Washington, DC 20250 or at

the Office of the Federal Register, 800 N. Capitol Street NW.,

Suite 700, Washington, DC 20001.

1.5 Bell Communications Research (Bellcore) document

SR-TSV-002275, BOC Notes on the LEC Networks - 1990, March 1991,

is incorporated by reference by RUS. This incorporation by
Bulletin 1753E-001 (Form 522)

Page I-2

Part I, January 1996

reference was approved by the Director of the Federal Register in

accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be

obtained from Bellcore Customer Service, 60 New England Avenue,

Piscataway, NJ 08854, telephone 1-800-521-2673. Copies may be

inspected during normal business hours at RUS, room 2838-S, U. S.

Department of Agriculture, Washington, DC 20250 or at the Office

of the Federal Register, 800 N. Capitol Street NW., Suite 700,

Washington, DC 20001.

1.6 Bellcore TR-TSY-000508, Automatic Message Accounting, July

1987, is incorporated by reference by RUS. This incorporation by

reference was approved by the Director of the Federal Register in

accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be

obtained from Bellcore Customer Service, 60 New England Avenue,

Piscataway, NJ 08854, telephone 1-800-521-2673. Copies may be

inspected during normal business hours at RUS, room 2838-S, U. S.

Department of Agriculture, Washington, DC 20250 or at the Office

of the Federal Register, 800 N. Capitol Street NW., Suite 700,

Washington, DC 20001.

1.7 Federal Standard H28, Screw-Thread Standards for Federal

Services, March 31, 1978, is incorporated by reference by RUS.

This includes: Change Notice 1, Federal Standard, Screw-Thread

Standards for Federal Services, May 28, 1986; Change Notice 2,

Federal Standard, Screw-Thread Standards for Federal Services,

January 20, 1989; and Change Notice 3, Federal Standard, ScrewThread Standards for Federal Services, March 12, 1990. This

incorporation by reference was approved by the Director of the

Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR

part 51. Copies may be obtained from the General Services

Administration, Specification Section, 490 East L'Enfant Plaza

SW, Washington, DC 20407, telephone 202-755-0325. Copies may be

inspected during normal business hours at RUS, room 2838-S, U. S.

Department of Agriculture, Washington, DC 20250 or at the Office

of the Federal Register, 800 N. Capitol Street NW., Suite 700,

Washington, DC 20001.

1.8 Institute of Electrical and Electronics Engineers (IEEE) Std

455-1985, IEEE Standard Test Procedure for Measuring Longitudinal

Balance of Telephone Equipment Operating in the Voice Band, is

incorporated by reference by RUS. This incorporation by

reference was approved by the Director of the Federal Register in

accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be

obtained from IEEE Service Center, 445 Hoes Lane, P. O. Box 1331,

Piscataway, NJ 08854, telephone (201) 981-0060. Copies may be

inspected during normal business hours at RUS, room 2838-S, U. S.

Department of Agriculture, Washington, DC 20250 or at the Office

of the Federal Register, 800 N. Capitol Street NW., Suite 700,

Washington, DC 20001.

1.9 Institute of Electrical and Electronics Engineers (IEEE) Std

730-1989, IEEE Standard for Software Quality Assurance Plans, is

incorporated by reference by RUS. This incorporation by
Bulletin 1753E-001 (Form 522)

Page I-3

Part I, January 1996

reference was approved by the Director of the Federal Register in

accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be

obtained from IEEE Service Center, 445 Hoes Lane, P. O. Box 1331,

Piscataway, NJ 08854, telephone (201) 981-0060. Copies may be

inspected during normal business hours at RUS, room 2838-S, U. S.

Department of Agriculture, Washington, DC 20250 or at the Office

of the Federal Register, 800 N. Capitol Street NW., Suite 700,

Washington, DC 20001.

1.10 RUS Bulletin 345-50, PE-60, RUS Specification for Trunk

Carrier Systems, September 1979,is incorporated by reference by

RUS. This incorporation by reference was approved by the

Director of the Federal Register in accordance with 5 U.S.C.

552(a) and 1 CFR part 51. Copies may be obtained from the Rural

Electrification Administration, Administrative Services Division,

room 0175-S, Washington, DC 20250. The bulletin may be inspected

at the Office of the Federal Register, 800 N. Capitol Street NW.,

Suite 700, Washington, DC 20001.

1.11 RUS Bulletin 345-55, PE-61, Central Office Loop Extenders

and Loop Extender Voice Frequency Repeater Combinations, December

1973, is incorporated by reference by RUS. This incorporation by

reference was approved by the Director of the Federal Register in

accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be

obtained from the Rural Electrification Administration,

Administrative Services Division, room 0175-S, Washington, DC

20250. The bulletin may be inspected at the Office of the

Federal Register, 800 N. Capitol Street NW., Suite 700,

Washington, DC 20001.

1.12 RUS Bulletin 345-87, PE-87, RUS Specification for

Terminating (TIP) Cable, December 1983, is incorporated by

reference by RUS. This incorporation by reference was approved

by the Director of the Federal Register in accordance with 5

U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from the

Rural Electrification Administration, Administrative Services

Division, room 0175-S, Washington, DC 20250. The bulletin may be

inspected at the Office of the Federal Register, 800 N. Capitol

Street NW., Suite 700, Washington, DC 20001.

2. RELIABILITY

2.1 Quality control and burn-in procedures shall be sufficient

so the failure rate of printed circuit boards does not exceed an

average of 1.0 percent per month of all equipped cards in the

central office during the first three months after cutover, and

an average of 0.5 percent per month of all equipped cards in the

central office during any 6-month period thereafter. A failure

is considered to be the failure of a component on the PC board

which requires it to be repaired or replaced.
Bulletin 1753E-001 (Form 522)

Page I-4

Part I, January 1996

2.2 The central office switching system shall be designed such

that the expected individual line downtime does not exceed 30

minutes per year. This is the interval that the customer is out

of service as a result of all failure types, excluding dispatch

and travel time, i.e., hardware, software, and procedural errors.

2.3 The central office switching system shall be designed such

that there will be no more than 1 hour of total outages in 20

years, excluding dispatch and travel time for unattended offices.

3. SYSTEM TYPE ACCEPTANCE TESTS

3.1 System type acceptance tests (general acceptance tests) are

performed for the purpose of determining whether or not a type of

switching system should be added or retained as an RUS accepted

system. While general acceptance tests will be required on each

system type, they will not be expected to cover every requirement

in this bulletin. However, any installation of a system provided

in accordance with this bulletin shall be capable of meeting any

requirement in this bulletin on a spot-check basis.

3.2 A "completed call" test shall be made part of these system

type acceptance tests. There shall be no more than two in 10,000

locally originating and incoming calls misdirected,

unsuccessfully terminated, prematurely disconnected or otherwise

failing as a result of equipment malfunction and/or equipment

failures, or as a result of transients, noise or design

deficiencies. This test shall be made with a load box with no

less than 10 lines access and 10 subscriber numbers for

completion, or equivalent, with no other traffic in the system.

If there is a failure in the equipment during this test, the

cause shall be repaired and the test restarted at zero calls.

3.3 System type acceptance testing applies basically to factory

type testing, and not to owner acceptance testing for individual

installations. The overall installed and operating system shall

also meet these requirements, except for unusual circumstances or

where specifically excluded by this or other RUS requirements.

4. TYPES OF REQUIREMENTS

4.1 Unless otherwise indicated, the requirements listed in this

bulletin are fixed requirements.

4.2 Optional requirements are those which may not be needed for

every office and are identifiable by a phrase such as, "when

specified by the owner," or, "as specified by the owner."

4.3 In some cases where an optional feature specified in

paragraph 5 of this bulletin will not be required by an owner,

either now or in the future, a system which does not provide this
Bulletin 1753E-001 (Form 522)

Page I-5

Part I, January 1996

feature will be considered to be in compliance with this bulletin

for the specific installation under consideration, but not in

compliance with the entire bulletin.

4.4 The owner may request bids from any RUS accepted supplier

whose system provides all the features which will be required for

a specific installation.

4.5 The Application Guide, RUS TE&CM 322, provides information

about the economic and service factors involved in all optional

features, as well as instructions for the completion of Parts III

and IV of this bulletin.

5. GENERAL REQUIREMENTS

5.1 The equipment shall provide for terminating and

automatically interconnecting subscriber lines and trunks in

response to dial pulses (or pushbutton dialing signals, if

specified) without the aid of an operator.

5.2 Complete flexibility shall be provided for assigning any

subscriber directory number to any central office line equipment

by the use of internal programmed memory. Thus, any subscriber

line and/or directory number may be moved to another terminal to

distribute traffic loads, if the line equipment hardware is

compatible with the service provided.

5.3 The system shall be arranged to interface with interexchange

carrier trunks and networks using single digit or multi-digit

access codes. The system shall be equipped to handle at least

20-digit subscriber dialed numbers. All subscriber directory

numbers in the office shall be seven-digit numbers.

5.4 The network and the control equipment shall be comprised of

solid-state and integrated circuitry components. Peripheral

equipment shall be comprised of solid-state and integrated

circuitry components as far as practical and consistent with the

state-of-the-art and economics of the subject system.

5.5 The basic switching system shall include the provision of

software programming and necessary hardware, including memory,

for optional custom calling services such as call waiting, call

forwarding, three-way calling, and abbreviated dialing. It shall

be possible to provide these services to any individual line

(single-party) subscriber. The addition of these services shall

not reduce the anticipated ultimate engineered line, trunk, and

traffic capacity of the switching system as specified in Part III

of this bulletin.

5.6 The requirements in this specification apply only to single

party lines. Although only single frequency ringing is required,

other types may be requested in Part III of this bulletin.
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5.7 Provision shall be made for local automatic message

accounting (LAMA), and for traffic service position system (TSPS)

trunks, or equivalent, to the operator's office when required

either initially or in the future.

5.8 Tandem switching features shall be provided if specified in

Part III of this bulletin.

5.9 The system shall be arranged to serve a minimum of eight All

Number Calling (ANC) office codes per office, with discrimination

on terminating calls by trunk group, numbering plan, or

programmed memory and class mark, if specified in Part III of

this bulletin.

5.10 Busy hour load handling capacity is an important feature

when an office approaches capacity. The delays which may occur

in call completion during busy hour periods may prove to be

excessive in some system designs. Accordingly, each bidder shall

provide, in Part V of this bulletin, data satisfactory to RUS

regarding the busy hour load handling capacity and traffic delays

of the system.

5.11 Provision shall be made for hotel-motel arrangements, as

required by the owner, to permit the operation of message

registers at the subscriber's premises to record local outdial

calls by guests (see Item 10.5, Part III of this bulletin).

5.12 Provision shall be made to identify the calling line or

incoming trunk on nuisance calls (see paragraph 7.10 of this

bulletin for details).

5.13 Full access from every subscriber line to every interoffice

trunk shall be provided.

5.14 Facilities shall be provided to implement service orders,

make traffic studies, and perform switching and transmission

tests by means of remote control devices if such operations are

specified in Items 11.2 and 11.3 of Part III of this bulletin.

5.15 Provision shall be made for the addition of facilities to

record all subscriber originated calls based on dialed directory

number, time of day, and duration of conversation. They shall be

such that the additional equipment (if any is required) may be

added to an in-service system without interruption of service and

a minimum of equipment, wiring and software modifications.

5.16 The system shall be capable of distributed switching

operation where groups of subscriber lines can be remotely

located from the central office. The remotely situated units are

known as "Remote Switching Terminals" (RST's) (see paragraph 23

of this bulletin). This does not eliminate the use of pair gain

devices such as direct digitally connected concentrators, regular
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concentrators or subscriber carrier equipment, where specifically

ordered by the owner and its engineer.

5.17 The switching system shall have means to synchronize its

clock with switches above it in the network hierarchy, when

specified by the owner in Item 3, Part III of this bulletin (see

paragraph 10 of this bulletin).

5.18 Consistent with system arrangements and ease of

maintenance, space shall be provided on the floor plan for an

orderly layout of future equipment bays that will be required for

anticipated traffic when the office reaches its ultimate size.

Readily accessible terminals shall be provided for connection to

interbay and frame cables to future bays. All cables, interbay

and intrabay (excluding power), if technically feasible, shall be

terminated at both ends by use of connectors.

5.19 When specified in Part III of this bulletin, the system

shall be capable of processing emergency calls to a 911 service

bureau connected either by a group of one-way 911 lines or a

trunk group.

5.19.1 It shall be possible to reach the service bureau by

dialing 911, 1+911, or a 7-digit number.

5.19.2 The system shall select an idle 911 line or trunk.

5.19.3 The system shall provide usual ringing and ringback

signal until the called 911 line answers.

5.19.4 If the calling line goes on-hook first, the system shall

hold the connection from the called 911 line and return steady

low tone to the service bureau. The system shall then begin a

45-minute timeout, after which the calling line is disconnected

and an alarm message is printed on a TTY. If the calling line

goes off-hook before timeout, the system shall reestablish the

conversation path.

5.19.5 If the calling line does not disconnect, the service

bureau attendant shall have the ability to force a disconnect of

the established connection with the calling party.

5.19.6 When the 911 call is answered, the equipment shall be

arranged so that coin lines are not charged for the call.

Similarly, if some form of local call charging is used, there

shall be no charge for the 911 call.

5.19.7 If the 911 service bureau is holding a calling line, it

shall be possible for the 911 line to cause the equipment to ring

back the calling line. This is done by providing a flash of

on-hook signal from the 911 line lasting from 200 to 1,100

milliseconds. The signal to the calling line shall be ringing
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current if the line is on-hook, or receiver off-hook (ROH) tone

if the line is off-hook.

5.19.8 Calls shall not be originated from the service bureau via

the dedicated 911 lines. If an attempt is made to originate a

call, it shall receive reorder tone. After 6 minutes, the system

shall print an alarm message.

5.19.9 If 911 calls pass through intermediate switching, the

forced-hold control, emergency ringback, and calling line status

monitoring capabilities are lost.

6. LINE CIRCUIT REQUIREMENTS

6.1 General

6.1.1 The range of direct current (dc) resistances of subscriber

loops, measured from the main frame in the central office and

including the telephone set shall be at least 0 - 1900 ohms

without loop extension and 1900 - 3600 ohms with loop extenders,

or equivalent. The range when using extension equipment may be

significantly reduced for straight line ringers. These limits

apply under maximum adverse environmental and manufacturing

variation tolerance conditions. Central office voltage shall be

stabilized at a value necessary to provide at least a nominal 21

milliamperes current with a nontreated loop of at least 1900

ohms. Minimum loop insulation resistance without loop extenders

shall be 25,000 ohms between conductors or from either conductor

or both conductors in parallel to ground. Loop insulation

resistance for loop extension devices may be 100,000 ohms minimum

between conductors or from either conductor or both conductors in

parallel to ground.

6.1.2 In addition to operating on nonloaded cable pairs and

subscriber carrier, the equipment shall function properly with

D-66 and H-88 loaded cable pairs, including any provisions the

equipment must control for the purposes of proper transmission.
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6.2 Dialing

6.2.1 Subscriber Dial Speed: The line equipment and central

office equipment (COE) in tandem shall operate satisfactorily

when used with subscriber dials having a speed of operation

between eight and twelve impulses per second and a break period

of 55 to 65 percent of the total impulse period.

6.2.2 Subscriber Dial Interdigital Time: The line equipment and

central office equipment shall operate satisfactorily with

subscriber rotary dial interdigital times of 200 milliseconds

minimum, and with pushbutton dialing interdigital times of 50

milliseconds minimum.

6.2.3 Subscriber Line Pushbutton Dialing Frequencies: The

frequency pairs assigned for pushbutton dialing shall be as

follows, with an allowable variation of + 1.5 percent:

Low Group High Group

Frequencies (Hz) Frequencies (Hz)

1209 1336 1477 1633

697 1 2 3 Spare

770 4 5 6 Spare

852 7 8 9 Spare

941 * 0 # Spare

The receiver shall comply with the operating parameters of the

dual-tone multifrequency (DTMF) central office receiver as

described in section 6 of Bell Communications Research (Bellcore)

document SR-TSV-002275, BOC Notes on the LEC Networks - 1990.

6.3 Impedance: For the purpose of this bulletin, the input

impedance of all subscriber loops served by the equipment is

arbitrarily considered to be 900 ohms at voice frequencies.

6.4 Lockout

6.4.1 All line circuits shall be arranged for line lockout.

When a permanent condition occurs prior to placing a line into

lockout, a timed low level warning followed by a timed high level

receiver off-hook (ROH) tone (see paragraph 9.2.11 of this

bulletin) or a howler circuit (see paragraph 15.2.3.3 of this

bulletin) shall be applied to the line.

6.4.2 The line on lockout shall be reconnected automatically to

the central office when the permanent off-hook condition is

cleared.

6.5 Pay Stations: Pay stations may be prepay, or semi-postpay,

as specified by the owner.
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Part I, January 1996

6.6 Loop Extension

6.6.1 The number of lines which exceed 1900 ohms will be

specified by the owner. When requested by the owner, the bidder

shall furnish equipment to guarantee satisfactory operation of

all lines.

6.6.2 Working limits for subscriber lines with loop extenders

are covered in RUS Bulletin 345-55, PE-61, Central Office Loop

Extenders and Loop Extender Voice Frequency Repeater

Combinations.

6.6.3 Ringing from RUS accepted loop extenders, or their

equivalent, shall be cut off from the called line when the

handset at the called station is removed during the ringing or

the silent interval.

6.7 Private Branch Exchange (PBX) Lines: PBX trunk hunting

shall be available. It will not be necessary to segregate PBX

lines to certain line groups.

6.8 Quantity: A sufficient number of terminations shall be

provided, in addition to the quantity specified by the owner for

subscriber line service, to meet the requirements of the system

for equipment testing, alarm checking, tone transfer, loop around

test and other features.

6.9 Types: There shall be provisions for types of lines such as

ground start, loop start, regular subscriber, pay stations, etc.

7. INTRAOFFICE SWITCHING REQUIREMENTS

7.1 The switching system shall:

7.1.1 Provide dial tone in response to origination of a call by

a subscriber, except on special lines where the application of

dial tone is not applicable, such as manual and hot lines;

7.1.2 Remove dial tone immediately after the first digit has

been dialed;

7.1.3 Recognize the class of service of the calling subscriber;

7.1.4 Register the digits dialed by the calling subscriber where

the rotary dial or pushbutton dialing characteristics and the

minimum interdigital times are as specified;

7.1.5 Perform the necessary translation functions when the

required number of digits have been registered, and select a

channel to a proper outgoing trunk, if one is available, to the

designated interexchange carrier;
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7.1.6 Provide a transmission path from the calling subscriber

line to the selected trunk, if an idle one is found;

7.1.7 Provide for more than one alternate route to the desired

destination when specified by the owner, select an idle outgoing

trunk in the first or second choice alternate route trunk group,

if all trunks in the higher choice groups are busy, and provide a

reorder signal (see paragraph 9.2.4 of this bulletin) to the

subscriber if no trunks are available in the last choice

alternate route;

7.1.8 Translate the proper part of the registered incoming

routing data on tandem calls into an identification of an

outgoing trunk group, select an idle trunk in that group,

initiate the connection of the incoming trunk to the outgoing

trunk, set the trunks in the proper configuration for tandem

operation, and transmit information as required to permit

completion to the desired destination in the distant office;

7.1.9 Transmit the proper stored information over the selected

trunk to permit completion of outgoing calls to the desired

destination by the distant office or offices, and provide

multifrequency (MF) outpulsing when specified;

7.1.10 Register all the digital information on calls incoming

from a distant office, when dial or MF pulsing characteristics

and interdigital times are as specified;

7.1.11 Translate internally a registered directory number into

line equipment location, ringing code and terminating class (such

as "PBX hunting") on incoming or intraoffice calls;

7.1.12 Test the called line for a busy condition;

7.1.13 Connect the incoming trunk or locally originated call to

the called line if the called line is idle;

7.1.14 Permit any type of ringing voltage available in the

central office to be associated with any Subscriber Directory

Number (SDN), cause the proper type of ringing voltage to be

connected to the called line, and remove ringing from the line

upon answer whether in the ringing or silent period; and

7.1.15 Test and monitor the switching system continually during

periods of low traffic using the maintenance and diagnostic

subsystem.

7.2 The switching system shall offer at least the following

originating and terminating class-of-service indications on a

per-line basis to subscribers, as specified by the owner:

7.2.1 Flat rate individual line, bridged ringing;
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Part I, January 1996

7.2.2 Flat rate PBX and trunk hunting numbers, bridged ringing;

7.2.3 Pay station;

7.2.4 Message rate subscriber line;

7.2.5 Wide Area Telephone Service (WATS);

7.2.6 Extended Area Service (EAS);

7.2.7 Data service;

7.2.8 Hotel-Motel capability;

7.2.9 Denied originating;

7.2.10 Denied terminating;

7.2.11 Custom calling features;

7.2.12 Special interexchange carrier accesses; and

7.2.13 Presubscription to designated interexchange carrier.

7.3 The switching system shall provide PBX hunting.

7.3.1 At least one trunk hunting group in each 100 SDN's

equipped shall be provided. More may be provided as specified by

the owner.

7.3.2 PBX groups shall be of a reasonable size commensurate with

the ultimate size of the switching system.

7.3.3 Any available SDN may be used for PBX trunk hunting.

7.3.4 Each PBX group shall have the capability of being assigned

one or more nonhunting SDN's for night service.

7.3.5 If the called line is a PBX hunting line, the switching

system shall test all assigned lines in the hunting group for a

busy condition.

7.3.6 If the called PBX group is busy, line busy tone, as

specified in paragraph 9.2.3 of this bulletin, shall be returned

to the originating end of the connection.

7.4 The switching system shall provide pay stations which may be

prepay or semi-postpay. The system shall be arranged so that an
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Part I, January 1996

operator and emergency service (911) may be reached from prepay

or semi-postpay coin lines without the use of a coin, when the

proper pay station equipment is provided.

7.5 To meet dialing requirements, the switching system shall:

7.5.1 Initiate the line lockout function after a delay, as

specified in paragraph 18.3 of this bulletin, if dial or

pushbutton dialing pulses are not received after initiation of a

call, preferably routing the subscriber line to a holding circuit

for tones and then automatically to lockout;

7.5.2 Connect 120 interruptions per minute (IPM) paths busy

tone, recorded message, or other distinctive tone to the calling

subscriber if an interval longer than that specified in paragraph

18.4 of this bulletin elapses between dialed digits;

7.5.3 Register the standard tone calling signals received from a

subscriber station arranged for pushbutton dialing if specified

by the owner, provide arrangements to function properly with

12-button pushbutton dialing sets, and return a reorder signal to

the subscriber upon receipt of signal from the 11th or 12th

buttons if neither of these buttons is assigned functions; and

7.5.4 Connect the incoming trunk to the digit register equipment

within 120 milliseconds after seizure where direct dialing is

received on calls from a distant office, cancel the bid for a

register, and return reorder tone to the calling end if dial

pulses are received before a register is attached.

7.6 The switching system shall provide for appropriate circuit

usage.

7.6.1 To avoid inefficient utilization of the switching network,

that portion of the common equipment that establishes the

connection on intramachine calls shall not require more than 500

milliseconds, exclusive of ringing and ring trip, to complete its

function under no-delay conditions.

7.6.2 The switching system shall provide for duplication in a

load sharing or redundant configuration any circuit elements or

components, the failure of which would reduce the grade of

service of 100 or more lines by more than 25 percent of the

traffic carrying capacity.

7.6.3 The switching system shall ensure that failure of access

to a high choice circuit will not prevent subsequent calls from

being served by lower choice circuits, wherever possible.

7.6.4 Where only two circuits of a type are provided, circuits

shall be designed so that failure of one circuit will not

permanently block any portion of the system for the duration of

the failure.
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Part I, January 1996

7.6.5 Where more than two circuits of a type are provided,

successive usages should be on a rotational or random basis

rather than the step-up selection with the possible exception of

a last choice trunk.

7.6.6 The system shall be designed so that, in the event of a

network failure, the system shall immediately or simultaneously

use a redundant portion of the network to complete the call.

7.7 The switching system shall provide busy verification

facilities with the method of access specified by the owner.

7.7.1 Only an operator or a switchman shall be able to override

a busy line condition.

7.7.2 If the called line is busy, off-hook supervision shall be

given the operator or switchman.

7.7.3 The responsibility of restricting subscribers in distant

offices from having access to busy verification shall be on the

distant office personnel when the toll trunks are used for both

toll connecting and verification traffic.

7.7.4 When a verification code is used, all digits of the code

must be dialed before cut-through to the called line can be

accomplished.

7.8 The switching system shall provide intercept facilities.

7.8.1 All unused numbering plan area codes, home numbering plan

area office codes, service codes and subscriber directory numbers

(SDN's) shall be routed to intercept. All intercept

administration shall be by changes in memory administrable by

telephone company personnel. Maximum machine time to place a

subscriber on intercept shall be 15 seconds.

7.8.2 Unequipped SDN's intercept shall be effective if the

processor memory does not have information concerning the SDN in

question.

7.8.3 The intercept equipment shall be arranged so that specific

SDN's can be routed to a separate intercept circuit for changed

numbers.

7.8.4 When an intercept call is answered, either by an operator

or by a recorded announcement, an off-hook or charge supervision

signal shall not be returned, even momentarily, to the

originating end.

7.8.5 When intercepting service is to be handled over the

regular interoffice toll trunks, a distinctive identifying tone

shall be transmitted when the operator answers. This tone shall
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Part I, January 1996

be of the frequency and duration specified in paragraph 9.2.10 of

this bulletin.

7.9 The switching system shall provide nuisance call trap

facilities which, when activated, provide a permanent record of

the calling and called numbers complete with date and time of

day. Where the call originates over an interoffice trunk, the

actual trunk number shall be recorded. There shall be provision

for the called subscriber to hold the connection and for the

positive trace of the call from origination to termination within

the office.

7.10 The switching system shall follow appropriate release

procedures.

7.10.1 The office shall be arranged so a connection to a

terminating channel other than assistance operator shall be

released under control of the calling party so that the channel

can be reseized, unless the call is to emergency 911 service or

other termination arranged for called party control.

7.10.2 If the called party disconnects first, the channel used

in the originally established connection shall be held until the

calling party disconnects or until the timing interval specified

in paragraph 18.7 of this bulletin has elapsed. This feature

shall not interfere with the normal operation of calls to

intercept, fire alarm, or other special services.

7.11 The switching system shall provide line load control

facilities, when specified by the owner, to give preference for

originating service to a limited group of subscribers during

emergencies.

7.11.1 These facilities may be activated manually by

input-output (I/O) device or automatically after a manual setting

of a key (or equivalent) to put line load control into effect, as

determined by the bidder. The automatic procedure is preferable.

7.11.2 Procedures shall be established to avoid the unauthorized

use of the line load control facilities.

7.11.3 Where automatic activation is provided, service may be

provided to small groups of nonemergency subscribers on limited

grade of service whenever the office load becomes low enough to

permit this to be done safely.

8. INTEROFFICE TRUNK CIRCUIT REQUIREMENTS

8.1 General

8.1.1 The bidder shall supply, as requested by the owner,

solid-state technology type trunk and signaling circuits of any
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Part I, January 1996

of the types described in RUS TE&CM 319, Interoffice Trunking and

Signaling, or, with the approval of RUS, any other more recent

and desirable types not as yet covered in the manual. For dc

signaling, the duplex (DX) and loop types of signaling are

preferred.

8.1.2 Trunks shall not be directly driven from the subscriber's

dial on outward calls.

8.1.3 In order to reduce the spares inventory and minimize

incidence of improper maintenance replacement of circuit

assemblies, the types of trunk circuits shall be kept to a

minimum. Variation in assemblies should be mainly limited to

variation in signaling modes.

8.1.4 Trunk circuits which connect with carrier or 4-wire

transmission facilities shall be arranged for 4-wire transmission

to avoid an intermediate 2-wire interface between a 4-wire

switching system and trunk facilities.

8.2 Quantity: Trunk quantities shall be as specified in Part

III of this bulletin. Sufficient space shall be provided for an

orderly layout of trunks. Trunks of a certain type going to the

same destination may be grouped together on the original

installation.

8.3 Requirements for Interoffice Connections

8.3.1 When operator trunks are used in common for both coin and

noncoin lines, they shall be arranged to provide an indication to

the operator by means of a visual signal or tone when calls are

from pay stations. When a tone is used, it shall be of the type

specified in paragraph 9.2.5 of this bulletin and shall be

connected to be heard only by the operator upon answer. It shall

be possible to repeat the tone signal.

8.3.2 There are no requirements for trunks arranged for manual

re-ring by a toll operator, either with the receiver on or off

the hook, except to coin stations with the receiver on the hook.

8.3.3 On calls from subscribers to the assistance operator, the

release of the connection shall be under control of the last

party to disconnect. An exception is operator control of

disconnect that is used on outgoing trunks to a TSP/TSPS system.

8.3.4 On calls originated by an operator, the release of the

connection shall be under control of the operator.

8.3.5 Where trunks with E and M lead signaling are used, the

trunk circuits for Type I signaling shall be arranged to place

ground on the M lead during the on-hook condition and battery on

the M lead in the off-hook condition. For E and M Type II, only

a make contact between the MA and MB lead will be required. In
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Part I, January 1996

either type, current limiting shall be provided in the E lead of

the trunk circuit itself, as required for proper operation. It

shall be assumed that connection equipment in the form of trunk

carrier, multiplex, or associated signaling apparatus furnishes

only a contact closure to ground (Type I) or to a signal ground

lead (Type II) for an off-hook condition on the E lead.

8.3.6 Where answer supervision is used to determine the

initiation of the charging interval for a call, such answer

supervision shall not be effective for charging until after the

elapse of the timing interval listed in paragraph 18.5 of this

bulletin.

8.3.7 When necessary, provision shall be made for reception of

start and stop dial signals on toll trunk equipment.

8.3.8 When trunks arranged for automatic message accounting

(AMA), toll ticketing, or centralized automatic message

accounting (CAMA) are specified by the owner, these trunks shall

provide the pertinent features described in paragraph 11 of this

bulletin applicable to such functions.

8.4 Requirements for Direct Digital Connections

8.4.1 Interface units which will permit direct digital

connection to other digital switches, channel banks and remote

line and/or trunk circuits over digital facilities shall be

provided when specified by the owner. The digital transmission

system shall be compatible with T1 type span lines using a DS1

interface and other digital interfaces that may be specified by

the owner. The RUS specification for the span line equipment is

Bulletin 345-50, PE-60, RUS Specification for Trunk Carrier

Systems.

8.4.2 Each interface circuit shall connect 24 voice channels to

the switching system from a 1.544 megabit per second DS1 bit

stream. The DS1 bit stream entering or exiting the system shall

be in the D3 format and the voice signals shall be encoded in 8

bit mu-255 PCM. The format and processing of the bit stream must

be compatible with characteristics of the D3 channel bank such as

alarm and maintenance characteristics. Loss of receive signal

(DS1) shall be detected and the equivalent of a carrier group

alarm shall be executed in 2.5 + 0.5 seconds. Loss of

synchronization shall be detected by slips, timing jitter, and

wander in accordance with industry standards.

8.4.3 Signaling shall be by means of MF or dial pulse (DP) and

the system which is inherent in the A and B bits of the D3

format. In the case where they are not used for signaling, the A

and B bits shall be used only for normal voice and data

transmission.
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9. TONE REQUIREMENTS

9.1 General: Tones shall be provided to indicate the progress

of a call through the office. Tone generators should be an

integral part of the switching systems. The tones should be

introduced digitally by the application of the appropriate bit

stream to the line or trunk circuit via the digital switching

network. The necessary precautions shall be made to ensure tone

sources automatically if the primary sources fail.

9.2 Tone Specifications

9.2.1 Dial tone shall consist of 350 Hz plus 440 Hz at a

composite level of -10 dBm0 which equates to -13 dBm0 per

frequency. This is the precise tone suitable for use with

pushbutton dialing.

9.2.2 Low tone shall consist of 480 Hz plus 620 Hz at a

composite level of -21 dBm0 which equates to -24 dBm0 per

frequency.

9.2.3 Line busy tone shall be low tone interrupted at 60 IPM,

with tone on 0.5 seconds and off 0.5 seconds.

9.2.4 Reorder, all paths busy, and no circuit tone shall be low

tone interrupted at 120 IPM, with tone on 0.25 seconds and off

0.25 seconds.

9.2.5 Identifying tone on calls from coin lines shall be

uninterrupted low tone.

9.2.6 High tone shall consist of 480 Hz at -17 dBm0.

9.2.7 Audible ringback tone shall consist of 440 plus 480 Hz at

a composite level of -16 dBm0 which equates to -19 dBm0 per

frequency.

9.2.8 The call progress tones listed in this bulletin are

described in Bellcore document SR-TSV-002275, BOC Notes on the

LEC Networks - 1990, section 6. The 350, 440, 480, and 620 Hz

tones shall be held at + 0.5 percent frequency tolerance and + 3

dB amplitude variation. The amplitude levels specified are to be

measured at the main distributing frame, excluding cable loss.

9.2.9 Distinctive tone, when required for alarm calls, or other

features, shall consist of high tone interrupted at 200 IPM with

tone on 150 ms and off 150 ms.

9.2.10 Identifying tone on intercepted calls shall consist of

uninterrupted high tone impressed on the trunk circuit 300 to 600

milliseconds following the operator's answer of intercepted

calls.
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9.2.11 An ROH circuit shall have output tones which do not

interfere with the pushbutton or multifrequency signaling tones.

The ROH tone may be introduced digitally internal to the system

near the overload level of +3 dBm0. No power adjustment will be

required. The frequency of the output shall be distinctive and

urgent in order to attract the subscriber's attention to an

off-hook situation. (Warning: In order to determine the signal

level, a frequency selective voltmeter must be used to determine

the level of each signal component and mathematical power

addition used to combine these measurements into a single level

value.)

9.2.12 During application of tones, office longitudinal balance

shall be maintained within 15 dB of that specified in paragraph

17.8 of this bulletin.

10. SYSTEM CLOCK

10.1 The central office clock and network synchronization system

shall have the ability to be synchronized with external clocks

for network synchronization, including detection of slips,

timing, jitter and wander, in a digital-to-digital environment or

operate initially in an independent network (refer to Bellcore

document SR-TSV-002275, BOC Notes on the LEC Networks - 1990,

section 11).

10.2 The end office central office system clock shall be a

Stratum 3 clock with:

10.2.1 A minimum long-term accuracy of +4.6 x 10-6 (+7 Hz @

1.544 MHz);

10.2.2 A minimum stability of 3.7 x 10-7/day upon loss of all

frequency references; and
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10.2.3 A "Pull-In Range" for the capability of synchronizing to

a clock with accuracy of +4.6 x 10-6.

10.3 The access tandem central office system clock shall be a

Stratum 2 clock with:

10.3.1 A minimum long-term accuracy of +1.6 x 10-8(+0.025 Hz @

1.544 MHz);

10.3.2 A minimum stability of 1 x 10-10/day upon loss of all

frequency references; and

10.3.3 A "Pull-In Range" for the capability of synchronization

to a clock with accuracy of +1.6 x 10-8.

11. SWITCHED ACCESS SERVICE ARRANGEMENTS

11.1 General: The equipment shall be capable of providing

Feature Group A, Feature Group B, Feature Group C, and Feature

Group D switched access service arrangements, as described in

Bellcore document SR-TSV-002275, BOC Notes on the LEC Networks -

1990, section 6 and section 15, including arrangements for

automatic number identification (ANI).

11.2 Operation

11.2.1 All equipment shall be arranged for Feature Group A (Line

Side Connection).

11.2.2 All equipment shall be arranged for Feature Group B given

that Part III of this bulletin requires the equipment of the

necessary trunks (Trunk Side Connection).

11.2.3 The equipment shall be arranged for Feature Group C on

the trunk groups specified in Part III of this bulletin. Even

though Part III of this bulletin specifies Feature Group D or

some other trunk group, it shall be possible through software

commands available to the owner to use Feature Group C signaling

protocols on a trunk group basis until such time that the trunk

group in question converts to Feature Group D signaling

protocols.

11.2.4 The equipment shall be arranged for Feature Group D on

the trunk groups specified in Part III of this bulletin.

11.2.5 Calls originating from coin lines toward switched access

service shall be arranged either to provide signaling protocols

for TSPS, or in the absence of TSPS-type service, such calls

shall be blocked.

11.2.6 The equipment shall be arranged for forwarding routing

information, calling party identification, and called party
Bulletin 1753E-001 (Form 522)

Page I-21

Part I, January 1996

numbers in the proper feature group protocols, by trunk group as

specified in Part III of this bulletin.

11.2.7 The equipment shall be arranged for AMA data collection

as specified in Part III of this bulletin by trunk group. Unless

otherwise specified by the owner, the equipment shall be arranged

to collect the billing data in the Bellcore AMA format as

described in Bellcore document TR-TSY-000508, Automatic Message

Accounting.

11.2.8 If specified in Item 9.4, Part III of this bulletin, the

equipment shall be arranged to store the billing data in a

pollable system. If specified in Item 9.5, Part III of this

bulletin, equipment shall be furnished to poll the pollable

systems associated with the contract.

12. FUSING AND PROTECTION REQUIREMENTS

12.1 General

12.1.1 The equipment shall be completely wired and equipped with

fuses, trouble signals, and arranged for printout of fault

conditions, with all associated equipment for the wired capacity

of the frames or cabinets provided.

12.1.2 Design precautions shall be taken to prevent the

possibility of equipment damage arising from the insertion of an

electronic package into the wrong connector, the removal of a

package from any connector, or the improper insertion of the

correct card in its connector.

12.2 Fuses: Fuses and circuit breakers shall be of an alarm and

indicator type, except where the fuses or breaker location is

indicated on the alarm printout. Their rating shall be

designated by numerals or color code on the fuse panel, where

feasible.

12.3 Components

12.3.1 Insofar as possible, all components shall be capable of

being continuously energized at rated voltage without injurious

results. Insofar as possible, design precautions shall be taken

to prevent damage to other equipment and components when a

particular component fails.

12.3.2 Printed circuit boards or similar equipment employing

electronic components shall be self-protecting against external

grounds applied to the connector terminals, where feasible.

Board components and coatings applied to finished products shall

be of such material or treated so they will not support

combustion.
Bulletin 1753E-001 (Form 522)

Page I-22

Part I, January 1996

12.3.3 Every precaution shall be taken to protect

electrostatically sensitive components from damage during

handling. This shall include written instructions and

recommendations (see Item 6.1,h of Part V of this bulletin).

13. SWITCHING NETWORK REQUIREMENTS

13.1 The Network

13.1.1 All networks shall be comprised of solid-state

components.

13.1.2 The switching network shall employ time division digital

switching and be compatible for connection to D3 type PCM channel

banks without conversion to analog.

13.1.3 Equipment shall be available as required to connect

analog lines and trunks, analog or digital service circuits,

digital carriers to RST's, D3 channel banks or other digital

switching units.

13.2 Network Quantity: Where the number of stages in the

switching network and their control varies with the capacity of

the system, sufficient equipment and wiring shall be supplied

initially in order that there will be no service interruptions

when additions are made up to the ultimate capacity as specified

in Part III of this bulletin. This does not imply the necessity

of supplying empty cabinets unless this is the only way the

necessary wiring can be accomplished.

14. STORED PROGRAM CONTROL (SPC) EQUIPMENT REQUIREMENTS

14.1 The system shall provide redundancy in call processing such

that the failure of a call processing unit does not degrade the

call processing capabilities of the switching system nor result

in the loss of established calls.

14.2 Programs shall be modular, flexible and structured. In the

interest of more dependable and more easily read programs, it is

desirable to use a language which is more person-oriented leaving

the detailed machine-oriented problems to a compiler program.

Quality assurance of all software programs shall be in accordance

with IEEE Std 730-1989, IEEE Standard for Software Quality

Assurance Plans, or equivalent.

14.3 The office administration program shall have checks within

it to prevent failure due to erroneous or inconsistent input

data. It shall safeguard against the possibility of upsetting

machine performance with improper instructions or information.

In addition, modular structure shall allow the use of a variety

of human-engineered service order formats. Service changes may
Bulletin 1753E-001 (Form 522)

Page I-23

Part I, January 1996

be performed remotely if so desired. Average machine time for

service change shall be 15 seconds or less. Service changes

shall not be registered in permanent memory until verified. The

access to the service change shall not have access to generic

program.

14.4 The switching system shall be able to offer, by request, at

least the following printouts of its routine stored data for

administrative purposes:

14.4.1 A list of all assigned directory numbers, in numerical

order, with their assigned class of service and line terminal

numbers;

14.4.2 A list of all directory numbers, in numerical order,

associated with a class of service;

14.4.3 A list of all unassigned line terminals;

14.4.4 Traffic data in proper form for separation studies in

accordance with the revenue separations procedures current at the

time of the contract;

14.4.5 All lines on lockout;

14.4.6 All lines assigned to intercept;

14.4.7 All available (unassigned) directory numbers in the

working thousands group; and

14.4.8 A list of equipment busied out for maintenance.

14.5 The printouts in paragraph 14.4 of this bulletin may be

delayed to times of light traffic.

14.6 Maintenance diagnostics shall be performed by a fault

recognition system utilizing both software and hardware, each

being used where they are most effective for maintenance and

reliability. In the economic interests of providing early and

efficient fault detection and accurate pinpointing of faulty

areas, it is desirable to have a comprehensive person-machine

interface supported by extensive automatic fault detection and

analysis, involving diagnostic software for fault resolution and

automatic recovery mechanisms to maintain continuous service.

Maintenance messages may be channeled to a remote maintenance

center if so desired.

14.7 Information in memory, having no requirement for changes to

be introduced in the maintenance or operation of the system, may

be stored in memory devices such as programmable read-only memory

(PROM) or other devices that cannot be reprogrammed in the field.
Bulletin 1753E-001 (Form 522)

Page I-24

Part I, January 1996

15. MAINTENANCE FACILITIES

15.1 Alarm Features, Including Alarm Sending

15.1.1 The equipment shall be arranged to provide audible and

visual alarms indicating fuse operation or other circuit

malfunctions resulting from component failure, crosses or open

wiring, or any other conditions affecting service which can be

detected economically.

15.1.2 The alarms shall be classified in accordance with their

effect on the system.

15.1.2.1 Catastrophic alarms demand immediate attention and

require notification of the highest level of supervisory

personnel. Conditions such as loss of service, loss of one or

more remote line switches or line concentrators connected through

Direct Digital Interface, loss of network control, and loss of

computer program in all processors shall produce catastrophic

alarms.

15.1.2.2 Major alarms demand rapid action. Conditions such as

loss of one or more groups of subscribers or trunk ports, blown

fuses for common groups of channels, loss of control to groups of

channels, failure of one or both redundant units, and total loss

of battery charging current for more than 15 minutes shall

produce major alarms.

15.1.2.3 Minor alarms indicate nonemergency conditions which

cause degraded service or fault conditions which causes the

system to operate within less-than-optimum performance.

Conditions discovered in automatic routining which have not shown

in the operation of the equipment but require attention and

cumulative line lockout (level adjustable) are examples of minor

alarm conditions.

15.1.3 When the office is arranged for unattended operation,

facilities shall be provided for extending the alarm indications

to an attended point.

15.1.4 When the use of a separate outside plant facility for

alarm sending is specified, the nature of the alarm may be

indicated to the distant point by machine printout or other

display device.

15.1.5 When alarm sending is accomplished over a regular

operator office trunk, the operator shall be apprised that the

call is an alarm indication by a distinctive tone, as specified

by the owner in Part III of this bulletin. It shall be possible

for the operator to determine at any time the presence of a

trouble condition by dialing a number set aside for that purpose.

This number shall also be accessible from lines classmarked for

this feature.
Bulletin 1753E-001 (Form 522)

Page I-25

Part I, January 1996

15.1.6 When the alarm sending circuit seizes an interoffice

operator trunk, the operator must dial the alarm checking code

over another trunk before the first trunk can be released except

where the alarm condition has disappeared first.

15.1.7 The alarm sending circuit shall have access to two or

more trunks if the trunks are used for subscriber traffic.

15.1.8 An alarm indication of higher priority shall supersede an

original alarm indication and reseize an interoffice operator

trunk.

15.1.9 In any group of offices purchased under one contract, the

same codes shall be used in each office for alarm checking and

test.

15.1.10 When the alarm checking number is dialed, the alarm

indications received shall be as follows:

15.1.10.1 Catastrophic alarm - No tone.

15.1.10.2 Major alarm - Continuous busy tone 60 IPM, unless

alarm is overridden.

15.1.10.3 Minor alarm - Continuous 1-ring code ringback tone,

unless alarm is overridden.

15.1.10.4 No trouble - Continuous 2-ring code ringback tone,

unless alarm is overridden.

15.1.11 Audible and visual local alarms and transmitted alarms

shall be provided as follows:

Delay Interval

Classification Local Alarms Alarms Transmitted

Catastrophic 0 0

Major 0 01

Minor 0 0 - 30 Min.

1Except no charge alarm delayed 15 minutes.

15.1.12 The central office alarm circuits shall be arranged to

provide optional wiring to transmit either a minor alarm or a

major alarm and a printout to accommodate various types of trunk

and subscriber carrier systems, microwave, mobile radio, other

transmission systems, and environmental protection systems with

different priorities when a set of contacts is closed in the

equipment of such systems and the alarm checking code is dialed.

The alarm relay shall be furnished by the supplier of the carrier
Bulletin 1753E-001 (Form 522)

Page I-26

Part I, January 1996

multiplex and/or mobile radio equipment. The option or options

shall be specified by the owner.

15.2 Trouble Location and Test

15.2.1 Equipment

15.2.1.1 A maintenance center shall be provided with a fault

recorder (printer and/or display) for troubles. Here, system and

sub-system visual trouble indications are shown for maintenance

aid.

15.2.1.2 The fault recorder shall provide a permanent or semipermanent record of the circuit elements involved whenever a

trouble is encountered. It shall be arranged to recognize an

existing fault condition and not cause multiple printouts of the

same fault, except during test routine.

15.2.2 Maintenance System

15.2.2.1 The maintenance system shall monitor and maintain the

system operation without interruption of call processing, except

for major failures.

15.2.2.2 The maintenance system shall provide both specialized

maintenance hardware circuits and an extensive software package

to enable maintenance to determine trouble to an individual card

or functional group of cards.

15.2.2.3 Maintenance programs may be both on-line and off-line.

On-line maintenance programs are activated by system errors and

shall be scheduled to execute call tests during low traffic

periods and periodic hardware tests at specific time intervals.

Programs shall provide diagnostic tools for the maintenance

personnel and be initiated by them.

15.2.2.4 Scheduled periodic hardware tests shall automatically

detect faults and alert maintenance personnel via alarm or

appropriate input/output device(s) at local and/or remote

locations.

15.2.2.5 Facilities shall be provided so that test calls can be

set up using pre-selected items of switching equipment.

15.2.2.6 The maintenance personnel shall be able to make tests

to determine if every trunk and every item of switching equipment

are functioning properly. Also, it shall be possible to make

each trunk and each SPC equipment, or part thereof, busy to

service calls. Where possible, equipment which is made busy to

service calls shall still be accessible for test calls.

15.2.3 Outside Plant and Subscriber Stations
Bulletin 1753E-001 (Form 522)

Page I-27

Part I, January 1996

15.2.3.1 A subscriber loop test set or equivalent shall be

provided either as a separate set or as a part of the maintenance

center, as specified in Item 11.2 of Part III of this bulletin.

This circuit shall include a high resistance volt-ohm meter,

wiring to tip and ring terminals to permit a portable wheatstone

bridge to be used, an operator's telephone circuit, a dial

circuit (and pushbutton dialing keys, if specified), outgoing

trunks to dial equipment for access to lines under test without

use of the main distributing frame (MDF) test shoe and the

necessary test keys. No dry cell batteries shall be accepted for

test potentials. Circuits shall be designed so that alternating

current (ac) induction on the line will have no effect on dc

measurements. All functions shall be under control of lever or

pushbutton keys. As a minimum the test system shall:

15.2.3.1.1 Test for bridged foreign electromotive force (EMF);

15.2.3.1.2 Test for regular line battery;

15.2.3.1.3 Test for booster battery voltage and polarity using

the test shoe;

15.2.3.1.4 Test for open circuits, short, tip ground, and ring

ground;

15.2.3.1.5 Test for tip or ring negative potential;

15.2.3.1.6 Test for capacitance of a subscriber's line;

15.2.3.1.7 Supply talking battery to the line with and without

booster battery;

15.2.3.1.8 Ring the subscriber through the test access circuit

or through a test shoe;

15.2.3.1.9 Test in and out of the central office; and

15.2.3.1.10 Supply a reverse polarity key for voltage readings,

except when positive or negative values are displayed directly.

15.2.3.2 An acceptable arrangement for making the tests shown in

paragraph 15.2.3.1 of this bulletin is to have them under

software control with results displayed at one of the system's

I/O ports.

15.2.3.3 A howler circuit for maintenance purposes, if ordered

by the owner, shall have output tones which do not interfere with

the pushbutton or multifrequency signaling tones. The harmonics

of the output tones shall be attenuated at least 26 dB below the

fundamental frequency for all load conditions. The frequency

stability shall be 2 percent or less for all output tones when

the unit is operated in the specified load and environmental

range. It shall be possible to vary the output voltage (power)
Bulletin 1753E-001 (Form 522)

Page I-28

Part I, January 1996

of the howler circuit. It shall remove tone and restore the line

to service when the telephone instrument receiver is placed onhook. The frequency of the output shall be chosen to be

distinctive and urgent in order to attract the subscriber's

attention to an off-hook situation.

15.2.3.4 When a dial speed test facility is specified by the

owner, it shall be accessed by dialing a special code and shall

return to the calling station readily identifiable signals to

indicate that the dial speed is slow, normal, or fast.

15.2.3.5 When the office is arranged for pushbutton dialing,

optional facilities shall be provided for testing the pushbutton

dialing equipment at the subscriber station.

15.2.3.6 When a system for testing subscriber lines in remote

offices from a test position in a centrally located office is

specified by the owner, it shall be capable of working with all

the central offices and RST's in the remote areas. This testing

equipment shall preferably be solid-state with a minimum of

electromechanical devices and shall operate from central office

battery. It shall be capable of working over any voice grade

telephone circuit and shall not require a dedicated trunk. There

shall be no interference to or from "in-band" voice channel

tones. When used over a network, the verification or access

shall be guarded to prevent unauthorized access by subscribers.

Access to this system shall only be available to the test

operator in all cases.

15.3 Transmission Testing

15.3.1 When transmission test circuits are specified in Item

11.3 of Part III of this bulletin, they shall permit testing of

trunks by a distant office without any assistance in the local

dial office. Analog test ports shall meet appropriate trunk

requirements. If Centralized Automatic Reporting on Trunks

(CAROT), or equivalent, is to be used, the equipment at the end

office shall comply with Bellcore document SR-TSV-002275, BOC

Notes on the LEC Networks - 1990, section 8, Item 2.

15.3.2 Transmission test circuits are available with a variety

of options. These include single frequency and multifrequency

tone generators with one or more generator output terminals,

quiet terminations, and loop around test arrangements for both

one-way and two-way trunks.

15.3.3 Where multifrequency generators are used, they are

usually arranged to provide a minimum of three frequencies. With

some equipment, up to seven additional frequencies may be

provided if needed. No industry standardization of test

frequencies is as yet provided. Therefore, it is important that

the selection of frequencies, the order in which they are applied

and the time interval for application of each frequency be agreed
Bulletin 1753E-001 (Form 522)

Page I-29

Part I, January 1996

upon by the connecting company and the RUS borrower and listed in

Part III of this bulletin in those situations where connecting

companies request the installation of multifrequency generators

in borrowers' central offices.

15.3.4 The milliwatt generator shall be solid-state and generate

the analog or digital equivalent of 1004 Hz. The milliwatt

generator shall be assigned to a 4-wire analog test port or be

digitally generated. All 2-wire and 4-wire voice frequency ports

are at a nominal 0 dBm0 level. The level of the 1004 Hz tone

generator shall appear at outgoing 2-wire and 4-wire ports at 0

dBm + 0.5 dB. For direct digital connections, the encoded output

shall be the digital equivalent of a 0 dBm0 + 0.5 dB signal.

15.3.5 Reference tone generators can be used individually or

they can be part of a loop around test arrangement. If both

single frequency and multifrequency reference tone generators are

to be provided, only one can be arranged as part of a loop around

test. Where a loop around arrangement is provided, the generator

output can be obtained by dialing singly one of the two line

terminals. By dialing the other line terminal singly, usually a

900 ohm resistor in series with a 2.16 microfarad capacitor is

connected to the circuit under test to act as a "quiet

termination" for noise measurements and other tests. Whenever

both line terminals are held simultaneously, both the milliwatt

supply and the quiet termination shall be lifted off and a "loop

around" condition established. This permits the overall loss to

be determined from the distant office by going out over one

trunk, looping around in the end office and returning over the

other trunk. The insertion loss of this test arrangement when

used in a loop around configuration should not exceed 0.1 dB at

the frequencies specified for the milliwatt supply. Unless

otherwise specified, continuous off-hook supervision is to be

provided on both line terminals to prevent collusive calling

without charge. It will be permissible to accomplish the quiet

termination by opening the 4-wire path internally and to

accomplish the loop around by digital switching.

15.3.6 Provision shall be made so that the milliwatt supply can

be manually patched to circuits.

15.3.7 Test jack access shall be provided for all interoffice

trunks of the voice frequency type. The jack access shall be

properly designated for line, drop, monitor, and signaling leads

plus any other jacks as requested by the owner. This may be

accomplished by a set of jacks located at the maintenance center

which have access to each trunk on a switching basis.
Bulletin 1753E-001 (Form 522)

Page I-30

Part I, January 1996

16. TRAFFIC

16.1 General Engineering Guidelines

16.1.1 The Traffic Table, based on the Erlang Lost-Calls-Cleared

Formula, shall be used for determining the quantity of

intraoffice paths, registers, and senders where full availability

conditions apply. The following table shows the traffic capacity

in CCS for 1 to 200 trunks at nine grades of service.

 TRAFFIC TABLE

 Full Availability for Random Traffic

 LOST-CALLS-CLEARED

Number Offered Traffic Expressed in CCS

Number

 of of

Trunks B-.001 .002  .005  .01 .02 .05 .1 .2 .5 Trunks

  

 1 0 0  0  0 1 2 4 9 36 1

 2 2 3  4  5 8 14 22 36 98 2

 3 7 9  13  17 22 32 46 69 165 3

 4 16 19  25  31 39 55 74 106 234 4

 5 27 32  41  49 60 80 104 144 304 5

  

 6 41 48  58  69 82 107 135 184 374 6

 7 57 65  78  90 106 135 168 224 445 7

 8 74 83  98  113 131 163 202 265 516 8

 9 92 103  120  136 156 193 236 307 586 9

 10 111 123  143  161 183 224 270 348 656 10

  

 11 131 145  166  186 210 255 306 391 729 11

 12 152 167  190  212 238 286 341 433 801 12

 13 174 190  215  238 266 318 377 476 872 13

 14 196 213  240  265 295 350 413 519 944 14

 15 219 237  266  292 324 383 449 562 1015 15

  

 16 242 261  292  320 354 415 486 605 1087 16

 17 266 286  318  347 384 449 523 648 1158 17

 18 290 311  345  376 414 482 560 692 1230 18

 19 314 337  372  404 444 515 597 735 1302 19

 20 339 363  399  433 474 549 634 779 1374 20

  

 21 364 388  427  462 505 583 671 823 1445 21

 22 389 415  455  491 536 617 709 866 1517 22

 23 415 441  483  521 567 651 747 910 1589 23

 24 441 468  511  551 599 685 784 954 1661 24

 25 467 495  540  580 630 720 822 998 1733 25

 

 26 493 523  568  611 662 754 860 1042 1805 26

 27 520 550  598  641 693 788 898 1086 1876 27

 28 546 578  627  671 725 823 936 1130 1948 28

 29 573 606  656  702 757 858 974 1174 2020 29

 30 600 634  685  732 789 893 1012 1218 2092 30
Bulletin 1753E-001 (Form 522)

Page I-31

Part I, January 1996

 TRAFFIC TABLE

 Full Availability for Random Traffic

 LOST-CALLS-CLEARED

Number Offered Traffic Expressed in CCS Number

 of of

Trunks B-.001 .002  .005  .01 .02 .05 .1 .2 .5 Trunks

  

 31 628 662  715  763 822 928 1050 1263 2164 31

 32 655 690  744  794 854 963 1089 1307 2236 32

 33 683 719  774  825 887 998 1127 1351 2308 33

 34 711 747  804  856 919 1033 1165 1395 2380 34

 35 739 776  834  887 951 1068 1203 1439 2452 35

  

 36 767 805  864  918 984 1104 1242 1484 2524 36

 37 795 834  895  950 1017 1139 1281 1528 2595 37

 38 823 863  925  981 1050 1174 1319 1572 2667 38

 39 851 892  955  1013 1083 1210 1358 1617 2739 39

 40 880 922  986  1044 1116 1246 1396 1661 2811 40

  

 41 909 951  1016  1076 1149 1281 1435 1706 2883 41

 42 937 980  1047  1108 1182 1317 1474 1750 2955 42

 43 966 1010  1078  1140 1215 1352 1512 1795 3027 43

 44 995 1040  1109  1171 1248 1388 1551 1839 3099 44

 45 1024 1070  1140  1203 1282 1424 1590 1884 3171 45

  

 46 1053 1099  1171  1236 1315 1459 1629 1928 3243 46

 47 1083 1129  1202  1268 1349 1495 1668 1973 3315 47

 48 1112 1159  1233  1300 1382 1531 1706 2017 3387 48

 49 1141 1189  1264  1332 1416 1567 1745 2062 3459 49

 50 1170 1220  1295  1364 1449 1603 1784 2106 3531 50

  

 51 1200 1250  1327  1397 1483 1639 1823 2151 3603 51

 52 1229 1280  1358  1429 1516 1675 1862 2195 3675 52

 53 1259 1310  1390  1462 1550 1711 1901 2240 3747 53

 54 1289 1341  1421  1494 1584 1747 1940 2285 3819 54

 55 1319 1371  1453  1527 1618 1783 1979 2329 3891 55

  

 56 1349 1402  1484  1559 1652 1819 2018 2374 3962 56

 57 1378 1432  1516  1592 1686 1856 2057 2418 4034 57

 58 1408 1463  1548  1625 1719 1892 2096 2463 4106 58

 59 1439 1494  1579  1657 1753 1928 2136 2508 4178 59

 60 1468 1525  1611  1690 1787 1965 2174 2552 4250 60

  

 61 1499 1556  1643  1723 1821 2001 2214 2597 4322 61

 62 1529 1587  1675  1756 1855 2037 2253 2642 4394 62

 63 1559 1617  1707  1789 1889 2073 2292 2687 4466 63

 64 1590 1648  1739  1822 1923 2110 2331 2731 4538 64

 65 1620 1679  1771  1855 1958 2146 2370 2776 4610 65
Bulletin 1753E-001 (Form 522)

Page I-32

Part I, January 1996

 TRAFFIC TABLE

 Full Availability for Random Traffic

 LOST-CALLS-CLEARED

Number Offered Traffic Expressed in CCS Number

 of of

Trunks B-.001 .002  .005  .01 .02 .05 .1 .2 .5 Trunks

  

 66 1650 1710  1803  1888 1992 2182 2409 2821 4682 66

 67 1681 1742  1835  1921 2026 2219 2449 2865 4754 67

 68 1711 1773  1867  1954 2060 2255 2488 2910 4826 68

 69 1742 1804  1900  1987 2094 2291 2527 2955 4898 69

 70 1773 1835  1932  2020 2129 2328 2566 3000 4970 70

  

 71 1803 1867  1964  2053 2163 2364 2606 3044 5042 71

 72 1834 1898  1997  2087 2197 2401 2645 3089 5114 72

 73 1865 1929  2029  2120 2232 2438 2684 3134 5186 73

 74 1895 1961  2061  2153 2266 2474 2723 3178 5258 74

 75 1926 1992  2093  2186 2300 2511 2763 3223 5330 75

  

 76 1957 2024  2126  2219 2335 2547 2802 3268 5402 76

 77 1988 2055  2159  2253 2369 2584 2841 3313 5474 77

 78 2019 2087  2191  2286 2404 2620 2881 3357 5546 78

 79 2050 2118  2223  2319 2438 2657 2920 3402 5618 79

 80 2081 2150  2256  2353 2473 2694 2959 3447 5690 80

  

 81 2112 2182  2289  2386 2507 2730 2999 3492 5762 81

 82 2143 2213  2321  2420 2542 2767 3038 3537 5834 82

 83 2174 2245  2354  2453 2577 2803 3077 3581 5906 83

 84 2206 2277  2386  2487 2611 2840 3117 3626 5977 84

 85 2237 2309  2419  2521 2646 2877 3156 3671 6049 85

  

 86 2268 2340  2452  2554 2680 2913 3196 3716 6121 86

 87 2299 2372  2485  2588 2715 2950 3235 3761 6193 87

 88 2331 2404  2517  2621 2750 2987 3275 3805 6265 88

 89 2362 2436  2550  2655 2784 3024 3314 3850 6337 89

 90 2393 2468  2583  2688 2819 3060 3353 3895 6409 90

  

 91 2425 2500  2616  2722 2854 3097 3393 3940 6481 91

 92 2456 2532  2649  2756 2889 3134 3432 3984 6553 92

 93 2488 2564  2682  2790 2923 3171 3471 4029 6625 93

 94 2519 2596  2715  2823 2958 3208 3511 4074 6697 94

 95 2551 2628  2748  2857 2993 3244 3551 4119 6769 95

  

 96 2582 2660  2781  2891 3028 3281 3590 4164 6841 96

 97 2614 2692  2814  2925 3063 3318 3630 4209 6913 97

 98 2645 2724  2847  2958 3097 3355 3669 4253 6985 98

 99 2677 2757  2880  2992 3132 3392 3708 4298 7057 99

 100 2709 2789  2913  3026 3167 3429 3748 4343 7129 100
Bulletin 1753E-001 (Form 522)

Page I-33

Part I, January 1996

 TRAFFIC TABLE

 Full Availability for Random Traffic

 LOST-CALLS-CLEARED

Number Offered Traffic Expressed in CCS Number

 of of

Trunks B-.001 .002  .005  .01 .02 .05 .1 .2 .5 Trunks

  

 105 2867 2950  3078  3196 3342 3613 3946 4567 7489 105

 110 3027 3112  3244  3366 3516 3798 4143 4792 7849 110

 115 3186 3275  3411  3536 3691 3983 4341 5016 8209 115

 120 3347 3437  3578  3707 3867 4168 4539 5241 8569 120

 125 3507 3601  3745  3878 4043 4353 4737 5465 8929 125

  

 130 3669 3765  3912  4049 4219 4539 4935 5689 9289 130

 135 3830 3929  4081  4221 4395 4724 5133 5914 9649 135

 140 3992 4093  4249  4392 4571 4910 5332 6138 10009 140

 145 4155 4258  4418  4564 4748 5095 5530 6363 10369 145

 150 4318 4423  4586  4737 4925 5282 5728 6587 10729 150

  

 155 4481 4589  4755  4909 5102 5467 5927 6812 11089 155

 160 4644 4755  4925  5082 5279 5654 6125 7037 11449 160

 165 4808 4920  5094  5255 5457 5840 6324 7261 11809 165

 170 4972 5087  5264  5428 5634 6026 6523 7486 12169 170

 175 5137 5253  5434  5602 5811 6213 6722 7710 12529 175

  

 180 5301 5420  5604  5775 5989 6399 6920 7935 12889 180

 185 5466 5587  5775  5949 6167 6586 7119 8160 13249 185

 190 5631 5754  5945  6123 6345 6773 7318 8384 13609 190

 195 5797 5922  6116  6296 6524 6960 7517 8609 13969 195

 200 5962 6089  6287  6471 6702 7146 7716 8834 14329 200

16.1.2 The traffic capacity for all interoffice trunks shall be

based on full availability, even though the distant office itself

is not engineered to provide full availability access.

16.1.3 The Traffic Table may also be used to determine the

approximate traffic capacity of high-usage intertoll trunks. The

traffic offered to high-usage groups may be read at B.10,

signifying that 10 percent of the traffic overflows to the

alternate route. This approximates the HU12 table used by AT&T.

16.1.4 In reading the trunk quantity from the table, the higher

quantity shall be used when the CCS load is three or more CCS

over the lower quantity. For example, the number of trunks

justified for 294 CCS at B.005 is 16, but for 295 CCS 17 trunks

are justified.

16.1.5 Limited availability is not permitted.

16.1.6 The traffic capacity in the following table should be

used for small trunk groups such as pay station, special service
Bulletin 1753E-001 (Form 522)

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Part I, January 1996

trunks, intercept and PBX trunks, unless otherwise specified in

Part III of this bulletin.

Number of Circuits Permissible CCS

1 10

2 20

3 30

4 40

16.1.7 The percentage of lines equipped for pushbutton dialing

is to be used to determine the number of tone receivers. Local

registers, if required, shall be supplied on the basis of all

dial pulse.

16.2 Grade of Service

16.2.1 Grade of service specifies the expected performance when

there are adequate service facilities for an assumed volume of

traffic. It is expressed as a portion of the total traffic

during a busy hour that cannot be terminated immediately or

within a predetermined time period due to congestion. This

places responsibility on the traffic engineers to specify

facilities which will be entirely satisfactory to the users and

which can be equipped at a price which will be accepted as

reasonable.

16.2.2 The number of calls encountering dial tone delay in

excess of 3 seconds, measured over the busy hour of the four

high-consecutive week (4HW) period, shall not be more than 1.5

percent.

16.2.3 The average post dialing delay objective for an

intraoffice call shall not exceed 1 second. This includes all

connect, operate, and translation time.

16.2.4 The line to line (intraoffice) network matching loss

objective shall be 0.02 or less.

16.2.5 The blocking probabilities related to trunks include both

"mismatch" probability and probability of "all trunks busy." It

is likely that the "mismatch" will be negligible in that many

digital central offices have essentially nonblocking switching

characteristics. The objectives for trunk connections are as

follows:

16.2.5.1 Subscriber to outgoing trunk objective 0.01 or less;

16.2.5.2 Incoming trunk to subscriber objective 0.02 or less;

and

16.2.5.3 Local trunk tandem objective 0.01 or less.
Bulletin 1753E-001 (Form 522)

Page I-35

Part I, January 1996

16.2.6 Groups of common service circuits are to be engineered

utilizing the full availability traffic tables that appear in

paragraph 16.1.1 of this bulletin at the following stipulated

probabilities:

16.2.6.1 Outgoing trunks to 2/6 MF or dial pulse senders at

B.001;

16.2.6.2 Incoming trunks to 2/6 MF receivers at B.001;

16.2.6.3 Incoming nondelay dial trunks to receivers at B.001;

and

16.2.6.4 Incoming trunks with start dial at B.01.

16.2.7 Remote Switching Terminals (RST's) shall meet the same

grade of service objectives as the host.

16.3 Holding Times: For the purpose of estimating the quantity

of common control circuits, the following average holding times

may be used. These holding times are conservative and represent

the average effective and ineffective call. If these holding

times are to be used, it must be so stated in Part III of this

bulletin.

16.3.1 The following average call holding times (HT) may be

used.

Type of Call HT - Seconds

Intraoffice 120

EAS 150

Special Service, Intercept, Verification 60

Toll, CLR 300

Toll, S-S 240

Toll, PPCS 270
Bulletin 1753E-001 (Form 522)

Page I-36

Part I, January 1996

16.3.2 The following average subscriber dialing holding times

may be used (times used to dial digits do not include machine

time).

Digits

Dialed

DP

Sec.

Pushbutton

Sec.

Operator, Non-Pay Station 1 4.7 3.4

Special Service 3 7.7 5.0

Local 7 13.7 8.2

EAS 7 13.7 8.2

DDD: 1/0+7 8 15.2 9.0

DDD: 1/0+10 11 19.7 11.4

Dialing Time Per Digit - 1.5 0.8

Dial Tone Response - 3.2 2.6

16.3.3 The following average incoming register holding times may

be used (times for digit registrations do not include machine

time).

Basic

Holding

Time (Sec.) Digits

Additional

Per Digit

MF Receiver from:

No. 5 Crossbar - Non-LAMA 1.4 4 0.14

No. 5 Crossbar - LAMA 2.3 4 0.14

Crossbar Tandem & 4A Toll 3.1 4 0.14

No. 1 ESS 1.4 4 0.14

Key Pulsing Switchboard 5.2 4 0.60

DP Receivers - 10 PPS from:

SxS 6.0 4 1.5

Dialing Switchboard 6.6 4 1.3

4A Toll 5.6 51 -

Crossbar Tandem 4.9 4 1.2

 1No reduction for fewer digits.
Bulletin 1753E-001 (Form 522)

Page I-37

Part I, January 1996

16.3.4 The following average sender holding times may be used

(does not include machine setup and release time).

Basic

Holding

Time (Sec.) Digits

Additional

Per Digit

MF Senders:

No. 5 Crossbar 1.5 4 0.14

Crossbar Tandem & 4A Toll1 2.0 4 0.14

TSP/TSPS 2.4 7 0.14

SxS - CAMA, Called Number 3.7 7 0.14

SxS - CAMA, Calling Number 1.3 7 -

DP Senders - 10 PPS:

With Overlap Pulsing2 9.1 Up to 6 1.8

Without Overlap Pulsing 4.6 4 1.2

1Add 1.3 seconds for ANI outpulsing on special toll (0+)

calls and on DDD calls if AMA is not provided.

2Assumes overlap outpulsing starting on receiving of third

digit; applies only to calls handled on direct trunk groups.

16.4 Traffic Data Requirements

16.4.1 Traffic measurements are composed of primarily two types

- counts and usage. The following types of traffic data

recording are required:

16.4.1.1 Peg count registers shall be incremented when a

successful network connection is established to a particular

circuit group such as trunks, senders, digital receivers, etc.

16.4.1.2 Overflow count registers shall be incremented when

access to a particular circuit group is denied due to all

resource busy condition.

16.4.1.3 Network blockage count registers shall be incremented

due to an unavailability of a path in an access or switching

matrix network.

16.4.1.4 Usage measurements of the length of time associated

with a particular setup event or network connection shall be

made. Usage data measurements are normally collected by scanning

circuit groups resources every 10 or 100 seconds to determine

busy/idle states. Measurements are accumulated and read directly

in CCS (hundred call seconds).

16.4.1.5 Service delay measurements shall provide percentage

counts of the calls for a particular service that are delayed
Bulletin 1753E-001 (Form 522)

Page I-38

Part I, January 1996

beyond a specified interval of time, e.g., calls not receiving

dial tone within 3 seconds after call origination.

16.4.2 Traffic data shall be stored in electronic storage

registers or block of memory consisting of one or more traffic

counters for each item to be measured. The registers listed in

paragraph 16.4.1 of this bulletin shall be associated with the

interoffice trunks, switching network and central control

equipment in such a manner that the register readings can be used

to determine the traffic load and flow to, from and within the

system. Two-way trunks shall be metered to indicate inward and

outward seizures. The bidder shall indicate what registers are

to be supplied and their purpose.

16.4.3 The measured data shall be shown on a printout. It

should be possible to have local or remote printout, or both.

Arrangement shall be made for automatic data printout on command

for 15-, 30-, or 60-minute intervals as required, and be arranged

for automatic start-stop and in accordance with revenue

separation procedures current at the time of contract.

16.4.4 All traffic records shall have dates and times and office

identification.

17. TRANSMISSION

17.1 General: The transmission characteristics will be governed

by the fact that the switching matrix will be based on digital

operation. Unless otherwise stated, the requirements are in

terms of analog measurements made from Main Distributing Frame

(MDF) to MDF terminals, excluding cabling loss.

17.2 Impedance: For the purpose of this bulletin, the nominal

input impedance of analog ports in an end office shall be 900

ohms for 2-wire ports and 600 ohms for 4-wire ports. Where the

connecting facility or equipment is other than this impedance,

suitable impedance matching shall be provided by the bidder when

specified by the owner.

17.3 Insertion Loss: The insertion loss in both directions of

transmission at 1004 Hz shall meet the following requirements

when measured with a 0 dBm input signal at 900 ohms (or 600 ohms,

when required) at a temperature of 77°F + 9°F (25°C + 5°C).

17.3.1 Trunk-to-Trunk or Trunk-to-Line: The loss shall be set

between 0 and 0.5 dB for 2-wire to 2-wire, 2-wire to 4-wire, or

4-wire to 4-wire voice frequency connections.

17.3.2 Line-to-Line: The loss shall be set between 0 and 2 dB.
Bulletin 1753E-001 (Form 522)

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Part I, January 1996

17.3.3 Direct Digital Interface: On a direct digital interface,

the loss through the office shall be adjusted to the proper level

in the receive side.

17.3.4 Stability: The long-term allowable variation in loss

through the office shall be + 0.5 dB from the loss specified by

the bidder.

17.4 Frequency Response (Loss Relative to 1004 Hz) shall meet

the following requirements.

17.4.1 Trunk-to-Trunk

Loss at 0 dBm0 Input1

Frequency (Hz) 2-Wire to 2-Wire 4-Wire to 4-Wire

60 20 dB Min.2 16 dB Min.2

200 0 to 5 dB 0 to 3 dB

300-3000 -0.5 dB to 1 dB -0.3 to +0.3 dB

3300 1.5 dB Max. 1.5 dB Max.

3400 0 to 3 dB 0 to 3 dB

 1(-) means less loss and (+) means more loss. 2Transmit End

17.4.2 Line-to-Line

Frequency (Hz) Loss at 0 dBm0 Input1

60 20 dB Min.2

300 -1 to +3 dB

600 - 2400 +1 dB

3200 -1 to +3 dB

1(-) means less loss and (+) means more loss.

 2Transmit End

17.4.3 Trunk-to-Line: The trunk-to-line frequency response

requirements shall be a compromise between those values specified

in paragraphs 17.4.1 and 17.4.2 of this bulletin.

17.5 Overload level: The overload level at 900 ohm impedance

shall be +3 dBm0.

17.6 Gain Tracking (Linearity) shall meet the following

requirements.
Bulletin 1753E-001 (Form 522)

Page I-40

Part I, January 1996

Input Signal Level1

Maximum

Gain Deviation

 +3 to -37 dBm0 +0.5 dB

-37 to -50 dBm0 +1 dB

 11004 Hz reference at 0 dBm0.

17.7 Return Loss

17.7.1 The specified return loss values are determined by the

service and type of port at the measuring (near) end. Two-wire

ports are measured (near end) at 900 ohms in series with 2.16

microfarads and 4-wire ports are measured at 600 ohms resistive.

17.7.2 Far end test terminations shall be as follows:

17.7.2.1 Loaded line circuit - 1650 ohms in parallel with the

series combination of .005 microfarads and 100 ohms;

17.7.2.2 Nonloaded line circuit - 800 ohms in parallel with the

series combination of .05 microfarads and 100 ohms;

17.7.2.3 Special service line circuit including electronic lines

and carrier lines - 900 ohms in series with 2.16 microfarads; and

17.7.2.4 Two-wire trunk - 900 ohms in series with 2.16

microfarads.

17.7.2.5 Four-wire trunk - 600 ohms.

17.7.3 For trunk-to-trunk (2-wire or 4-wire) connections the

echo return loss (ERL) shall be 27 dB, minimum and the singing

return loss (SRL) shall be 20 dB, minimum low and 23 dB, minimum

high.

17.7.4 For trunk-to-line (2-wire or 4-wire) connections the ERL

shall be 24 dB, minimum and the SRL shall be 17 dB, minimum low

and 20 dB, minimum high.

17.7.5 For line-to-line or line-to-trunk (2-wire or 4-wire)

connections the ERL shall be 18 dB, minimum and the SRL shall be

12 dB, minimum low and 15 dB, minimum high.

17.8 Longitudinal Balance: The minimum longitudinal balance,

with dc loop currents of 20 to 70 mA, shall be 60 dB at all

frequencies between 60 and 2000 Hz, 55 dB at 2700 Hz and 50 dB at

3400 Hz. The method of measurement shall be as specified in the

IEEE Std 455-1985, Standard Test Procedure for Measuring

Longitudinal Balance of Telephone Equipment Operating in the

Voice Band. Source voltage level shall be 10 volts

root-mean-square (rms).
Bulletin 1753E-001 (Form 522)

Page I-41

Part I, January 1996

17.9 60 Hz Longitudinal Current Immunity: Under test conditions

with 60 Hz, the system noise shall be no greater than 23 dBrnC0

as measured using the configuration in Figure 1.

17.10 Steady Noise (idle channel at 900 ohms impedance) measured

on a terminated call shall be 23 dBrnC0 maximum and average 18

dBrnC0 or less. The 3K Hz Flat noise should be less than 35

dBrnC0 as an objective.

17.11 Impulse Noise: The central office switching equipment

shall be capable of meeting an impulse noise limit of not more

than five counts exceeding 54 dBrnC0 voice band weighted in a

5-minute period on six such measurements made during the busy

hour. A Northeast Electronics Company TTS 4002 Impulse Noise

Counter, Wilcom T194C, Hewlett Packard 4945, or equivalent,

should be used for the measurements. The measurement shall be

made by establishing a normal connection from the noise counter

through the switching equipment in its off-hook condition to a

quiet termination of 900 ohms impedance. Office battery and

signaling circuit wiring shall be suitably segregated from voice

and carrier circuit wiring, and frame talking battery filters

provided, if and as required, in order to meet these impulse

noise limits.

17.12 Crosstalk Coupling: Worst case equal level crosstalk is

to be 75 dB minimum in the range 200 - 3400 Hz. This is to be

measured between any two paths through the system connecting a 0

dBm0 level tone to the disturbing pair.

17.13 Quantizing Distortion

17.13.1 The switching system shall meet the following

requirements.

Input Level (dBm0)

1004 or 1020 Hz

Minimum Signal to Distortion

with C-Message Weighting

 0 to -30 33 dB

-30 to -40 27 dB

-40 to -45 22 dB

17.13.2 Due to the possible loss of the least significant bit on

direct digital connections, a signal to distortion degradation of

up to 2 dB may be allowed where adequately justified by the

bidder.

17.14 Absolute Delay: The absolute one-way delay through the

switching system, excluding delays associated with RST switching,

shall not exceed 1000 microseconds analog-to-analog measured at

1800 Hz.
Bulletin 1753E-001 (Form 522)

Page I-42

Part I, January 1996

17.15 Envelope Delay Distortion: On any properly established

connection, the envelope delay distortion shall not exceed the

following limits.

Frequency Range (Hz) Microseconds

1000 to 2600 190

 800 to 2800 350

 600 to 3000 500

 400 to 3200 700

17.16 Digital Error Rate: The digital switching system shall

not introduce an error into digital connections which is worse

than one error in 108 bits averaged over a 5-minute period.

17.17 Battery Noise: Noise across battery at power board

distribution bus terminals shall not exceed 35 dBrnC during the

busy hour.

17.18 Radio and Television Interference: The central office

switching equipment shall be designed and installed so that

radiation of high frequency noise will be limited so as not to

interfere with radio and television receivers.

18. TIMING INTERVALS

18.1 Type of Equipment Required: The equipment for providing

the specified timing intervals shall be solid-state.

18.2 Tolerance: Where a range of time is specified as minimum

and maximum, the lower limits shall be considered as controlling

and the variation between this minimum and the actual maximum

shall be kept as small as practicable. In no case shall the

quoted upper limit be exceeded.

18.3 Permanent Signal Timing: Lockout shall occur after an

interval of 20 to 30 seconds after receipt of dial tone if a

"permanent" condition occurs prior to the transmission of dial

pulses or pushbutton dialing signals. This interval may be

reduced appreciably during periods of heavy traffic.

18.4 Partial Dial Timing: Partial dial timing shall be within

15 to 37 seconds. This timing may be reduced appreciably during

periods of heavy traffic.

18.5 Charge Delay Timing: Charge delay timing shall be within 2

seconds.

18.6 Called Party Disconnect Timing: Timed disconnect of a

terminating path under control of the called party shall be 10 to

32 seconds.
Bulletin 1753E-001 (Form 522)

Page I-43

Part I, January 1996

18.7 Timing Intervals for Signals Involved in Distance Dialing:

Timing intervals shall be provided to meet the requirements for

distance dialing equipment, which have been established in

Bellcore document SR-TSV-002275, BOC Notes on the LEC Networks -

1990. Some of the more important times which this document

specifies are for:

18.7.1 Disconnect signal;

18.7.2 Wink signal;

18.7.3 Start dialing signal;

18.7.4 Pulse delay signal;

18.7.5 Go signal;

18.7.6 Digit timing; and

18.7.7 Sender, register, and link attachment timing.

19. POWER REQUIREMENTS AND EQUIPMENT

19.1 Operating Voltage: The nominal operating voltage of the

central office shall be 48 volts dc, provided by a battery with

the positive side tied to system ground.

19.2 Batteries

19.2.1 When battery cells of the lead antimony type are

specified, the pasted plate type shall be considered adequate.

19.2.2 When lead calcium cells are specified, no cell shall

differ from the average voltage of the string of fully charged

cells by more than +0.03 volt when measured at a charging rate in

amperes equivalent to 10 percent of the ampere hour capacity of

the cells. Similarly, when cells are fully charged and floating

between 2.30 and 2.33 volts per cell, the cell voltage of any

cell in a given string shall not differ more than +0.03 volt from

the average. These requirements are for test purposes only and

do not apply to operating conditions.

19.2.3 Voltage readings shall be corrected by a temperature

coefficient of 0.0033 volt per degree F (0.006 per degree C),

whenever temperature variations exist between cells in a given
Bulletin 1753E-001 (Form 522)

Page I-44

Part I, January 1996

string. This correction factor shall also be applied when

comparing cell voltages taken at different times and at different

temperatures. The correction factor shall be added to the

measured voltage when the temperature is above 77°F (25°C) and

subtracted when the temperature is below 77°F (25°C).

19.2.4 The specific gravity readings of lead antimony cells at

full charge shall be 1.210 + .010 at 77°F (25°C) at maximum

electrolyte height.

19.2.5 When counter cells are supplied by the bidder, they shall

be the dry counter electromotive force (CEMF) type.

19.2.6 When lead antimony batteries are specified, they shall be

designed to last a minimum of 10 years when maintained on a full

float operation between 2.15 and 2.17 volts per cell. When lead

calcium batteries are specified, they shall be designed to last a

minimum of 20 years when maintained on full float operation

between 2.17 and 2.25 volts per cell. The battery shall be

clearly designated as "antimony" or "calcium" by means of

stencils, decals or other devices.

19.2.7 Each battery cell shall be equipped with an explosion

control device.

19.2.8 The battery size shall be calculated in accordance with

standard procedures. The battery in no case shall have a reserve

capacity in ampere hours less than four times the current

capacity of the largest charger.

19.3 Charging Equipment

19.3.1 Charging shall be on a full float basis. The rectifiers

shall be of the full wave, self-regulating, constant voltage,

solid-state type and shall be capable of being turned on and off

manually.

19.3.2 When charging batteries, the voltage at the battery

terminals shall be adjustable and shall be set at the value

recommended for the particular battery being charged, providing

it is not above the maximum operating voltage of the switching

system equipment. The voltage shall not vary more than plus or

minus 0.02 volt per cell between 10 percent load and 100 percent

load. Between 3 percent and 10 percent load, the output voltage

shall not vary more than plus or minus 0.04 volt per cell.

Beyond full load current, the output voltage shall drop sharply.

The output voltage shall be maintained with the line voltage

variations of plus or minus 10 percent. Provision shall be made

to change the output voltage of the rectifier manually to 2.25

volts per cell to provide an equalization charge on the battery.
Bulletin 1753E-001 (Form 522)

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Part I, January 1996

19.3.3 The charger noise shall not exceed 22 dBrnC when measured

with a suitable noise measuring set and under the rated battery

capacitance and load conditions as determined in Figure 2.

19.3.4 The charging equipment shall indicate a failure of

charging current, whether due to ac power failure, an internal

failure in the charger, or to other circumstances which might

cause the output voltage of the charger to drop below the battery

voltage. Where a supplementary constant current charger is used,

an alarm shall be provided to indicate a failure of the charger.

19.3.5 Audible noise developed by the charging equipment shall

be kept to a minimum. Acoustic noise resulting from operation of

the rectifier shall be expressed in terms of dB indicated on a

sound level meter conforming to ANSI S1.4, Specification for

Sound Level Meters, and shall not exceed 65 dB (A-weighting)

measured at any point 5 feet (152.4 cm) from any vertical surface

of the rectifier.

19.3.6 The charging equipment shall be designed so that neither

the charger nor the central office switching equipment is subject

to damage in case the battery circuit is opened for any value of

load within the normal limits.

19.3.7 The charging equipment shall have a capacity to meet the

requirements of central office size and special requirements of

the owner in Part III of this bulletin.

19.3.8 Minimum equipment requirement for chargers is one of the

following:

19.3.8.1 Two chargers either capable of carrying the full office

load as specified in Item 12 of Part III of this bulletin; or

19.3.8.2 Three chargers each capable of carrying half the office

load as specified in Item 12 of Part III of this bulletin.

19.4 Miscellaneous Voltage Supplies

19.4.1 Any power supply required for voltages other than the

primary battery voltage shall be provided by either a solid-state

dc-to-dc converter or dc-to-ac inverter, operating from the

central office battery or from a separate battery and charger.

These power supplies shall meet the noise limit specified for

chargers in paragraph 19.3.3 of this bulletin, except the

capacitor "C" shall be eliminated and the resistive load "R"

shall be determined by the nominal output voltage in volts

divided by the full load current rating in amperes. This

requirement does not preclude the use of commercial ac power to

operate input/output devices.

19.4.2 Power converters required for the purpose of providing

various operating voltages to printed circuit boards or similar
Bulletin 1753E-001 (Form 522)

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Part I, January 1996

equipment employing electronic components shall be provided in

duplicate with each unit capable of immediately assuming the full

operating load upon failure of a unit. An exception to the

duplicate power converter requirement permits nonduplicated power

converter(s) to be utilized where there is full compliance with

the following criteria.

19.4.2.1 The failure of any single nonduplicated power converter

shall not reduce the grade of service of common control and

service circuits to any individual line or trunk by more than 50

percent.

19.4.2.2 The failure of any single nonduplicated power converter

shall not reduce the traffic carrying capacity of any interoffice

trunk group by more than 50 percent.

19.4.2.3 In central office switching systems of 400 or more

equipped lines, any single nonduplicated power converter failure

shall not cause a complete loss of service to more than 100

equipped lines.

19.4.2.4 In central office switching systems of less than 400

equipped lines, any single nonduplicated power converter failure

shall not cause a complete loss of service to more than 25

percent of the total equipped lines.

19.5 Ringing Generators: Ringing generators supplied on an

ancillary basis shall be selected from RUS Bulletin 1755I-100,

List of Materials Acceptable for Use on Telephone Systems of RUS

Borrowers. Regardless of whether the ringing is generated on an

ancillary basis or is generated integrally to the switching

system, the ringing equipment shall meet the requirements of this

bulletin.

19.5.1 Ringing Equipment Provisioning

19.5.1.1 Redundant ringing equipment shall be provided. There

shall be automatic transfer to the redundant equipment within the

period of one ringing cycle, in case of failure of the equipment

in use (either regular or standby). Automatic transfer shall not

take place under any other conditions. Manual transfer in each

direction shall be provided.

19.5.1.2 An exception to the redundant ringing equipment

requirement permits nonredundant ringing equipment to be utilized

where there is full compliance with the following service

criteria.

19.5.1.2.1 In a central office switching system of 400 or more

equipped lines, a single nonduplicated ringing source failure

shall not cause the complete loss of ringing capability to more

than 100 lines.
Bulletin 1753E-001 (Form 522)

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Part I, January 1996

19.5.1.2.2 In a central office switching system of less than 400

equipped lines, a single nonredundant ringing source failure

shall not cause the complete loss of ringing capability to more

than 25 percent of the total equipped lines.

19.5.2 Output Voltage

19.5.2.1 The ringing generators shall have an output voltage

which approximates a sine wave and, as a minimum, shall be

suitable for ringing straight-line ringers. Although not a

requirement for RUS listing, decimonic, synchromonic, or harmonic

ringing may also be specified in Part III of this bulletin.

19.5.2.2 The ringing generator shall obtain its energy from the

nominal 48-volt office battery.

19.5.2.3 The output of each generator shall have three or more

voltage taps or a single tap with associated variable control.

Taps or control shall be easily accessible as installed in the

field. Software control of ringing generator outputs via I/O

devices may be provided in lieu of taps. The taps, or

equivalent, shall be designated L, M, and H. The variable

control shall have a locking device to prevent accidental

readjustment. The outputs at the terminals of the generators

with a voltage input of 52.1 volts and rated full resistive load

shall be as follows for the ringing frequencies provided.

Output Volts rms

(Tolerance 3 Volts)

Frequency Range (Hz) L M H

16 2/3 through 20 90 105 120

21 through 30 95 110 120

31 through 42 100 115 130

43 through 54 110 125 140

19.5.2.4 No voltages in excess of the values in column H of the

table in paragraph 19.5.2.3 of this bulletin shall be provided at

the output taps. Additional intermediate and/or lower taps may

be provided without restriction.

19.5.3 Voltage Regulation

19.5.3.1 The output voltage for resistive, capacitive power

factor of 0.8, and inductive power factor of 0.5 loads from no

load to full rated output with 52.1 volts input battery shall not

vary more than +3 percent from the output voltage measured at 1/2

rated output, 1.0 power factor with 52.1 volts dc input applied.

19.5.3.2 The output voltage for resistive, capacitive power

factor of 0.8, and inductive power factor of 0.5 from no load to
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Part I, January 1996

full rated output with input battery variations between 48 - 56

volts dc shall not vary more than + 10 percent from the output

voltage measured at 1/2 rated output and 1.0 power factor with

52.1 volts dc input applied.

19.5.3.3 The output voltage for resistive, capacitive power

factor of 0.8, and inductive power factor of 0.5 loads from no

load to full rated output and with input battery variations

between 44 - 56 volts dc shall not vary more than +10/-15 percent

from the output voltage measured at 1/2 rated output and 1.0

power factor with 52.1 volts dc input applied.

19.5.4 Cross Ringing: Unwanted voltage caused by harmonic

distortion or intermodulation distortion shall not exceed 15

volts rms when measured within +5 Hz of any other assigned

ringing frequency under any condition of load or input battery

specified by paragraph 19.5.3 of this bulletin.

19.5.5 Frequency Stability: At ambient temperature of 70° +5°F

(21° +0.3°C), for any combination of capacitive power factor of

0.8, inductive power factor of 0.5, and resistive loads with

variations in input battery ranging from 44 to 56 volts, the

output frequency shall not vary more than +1/3 Hz or +1 percent,

whichever is less stringent. At temperatures between 15°F (4°C)

to 130°F (54°C), and for any combination of resistive load and

variations in input battery ranging from 44 - 56 volts, the

output frequency shall not vary more than +1/3 Hz or +1 percent,

whichever is less stringent.

19.5.6 Self-protection on Overloads: The ringing generator

equipment shall be capable of withstanding a short circuit across

any pair of output terminals for a period of 5 minutes without

fuse operation or damage.

19.6 Interrupter Equipment

19.6.1 The interrupter shall be an integral part of the

switching system and shall be controlled by any call processor or

equivalent.

19.6.2 The ringing cycle provided by the interrupter equipment

shall not exceed 6 seconds in length. The ringing period shall

be 2 seconds.

19.7 Power Panels

19.7.1 Battery and charger control switches, dc voltmeters, dc

ammeters, fuses and circuit breakers, supervisory and timer

circuits shall be provided as required. Voltmeters shall be

provided as specified by the owner.
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Part I, January 1996

19.7.2 Portable or panel mounted frequency meters shall be

provided as specified by the owner unless the system is equipped

to measure actual ringing generator voltage and frequency outputs

internally. If the system is equipped to make such measurements

and print the results, the bidder is not required to provide a

frequency meter.

19.7.3 Power panels, cabinets and shelves, and associated wiring

shall be designed initially to handle the exchange when it

reaches its ultimate capacity as specified by the owner.

19.7.4 The power panel shall be of the "dead front" type.

20. MAIN DISTRIBUTING FRAMES

20.1 The main distributing frame shall provide terminals for

terminating all incoming cable pairs. Arresters shall be

provided for all incoming cable pairs, or for a smaller number of

pairs if specified, provided an acceptable means of temporarily

grounding all terminated pairs which are not equipped with

arresters is furnished.

20.2 The current carrying capacity of each arrester and its

associated mounting shall coordinate with a #22 gauge copper

conductor without causing a self-sustaining fire or permanently

damaging other arrester positions. Where all cable pairs

entering the central office are #24 gauge or finer, the arresters

and mountings need only coordinate with #24 gauge cable

conductors. Item 13 of Part III of this bulletin designates the

gauge of the cable conductors serving the host office. Item 7 of

Part IV of this bulletin designates the gauge of the cable

conductors serving the RST(s).

20.3 Central office protectors shall be mounted and arranged so

that outside cable pairs may be terminated on the left side of

protectors (when facing the vertical side of the MDF) or on the

back surface of the protectors. Means for easy identification of

pairs shall be provided.

20.4 Protectors shall have a "dead front" (either insulated or

grounded) whereby live metal parts are not readily accessible.

20.5 Protectors shall be provided with an accessible terminal of

each incoming conductor which is suitable for the attachment of a

temporary test lead. They shall also be constructed so that

auxiliary test fixtures may be applied to open and test the

subscriber's circuit in either direction. Terminals shall be

tinned or plated and shall be suitable for wire wrapped,

insulation displacement or connectorized connections.
Bulletin 1753E-001 (Form 522)

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Part I, January 1996

20.6 If specified in Part III of this bulletin, each protector

group shall be furnished with a factory assembled tip cable for

splicing to the entrance cable; the tip cable to be 20 feet (610

cm) in length unless otherwise specified. Factory assembled tip

cable shall be #22 gauge and selected from RUS Bulletin 1755I100, List of Materials Acceptable for Use on Telephone Systems of

RUS Borrowers. Tip cable requirements are provided in RUS

Bulletin 345-87, PE-87, RUS Specification for Terminating (TIP)

Cable. Cables having other kinds of insulation and jackets which

have equivalent resistance to fire and which produce less smoke

and toxic fumes may be used if specifically approved by RUS.

20.7 Protectors shall be mounted on vertical supports, with

centers not exceeding 9 inches (22.9 cm). The space between

protector units shall be adequate for terminating conductors.

20.8 Cable supporting framework shall be provided between the

cable entrance and the MDF when overhead cable entrance is

specified in Item 14.3.3 of Part III of this bulletin.

20.9 The main distributing frame shall be equipped with a copper

ground bus bar having the conductivity of a #6 American Wire

Gauge (AWG) copper conductor or a greater conductivity, or may

consist of another metal if specifically approved, provided it

has adequate cross-sectional area to provide conductivity

equivalent to, or better than, bare copper. A guardrail or

equivalent shall also be furnished.

20.10 Other features not specified in paragraph 20 of this

bulletin may be required at the option of the owner, if checked

in Item 13.4 of Part III of this bulletin.

20.11 Main frame protector makes and types shall be selected

only from RUS Bulletin 1755I-100, List of Materials Acceptable

for Use on Telephone Systems of RUS Borrowers. Protectors shall

be capable of easy removal.

21. ELECTRICAL PROTECTION

21.1 Surge Protection

21.1.1 Adequate electrical protection of central office

switching equipment shall be included in the design of the

system. The characteristics and application of protection

devices shall be such that they enable the central office

switching equipment to withstand, without damage or excessive

protector maintenance, the dielectric stresses and currents that

are produced in line-to-ground and tip-to-ring circuits through

the equipment as a result of induced or conducted lightning or

power system fault-related surges. All wire terminals connected

to outside plant wire or cable pairs shall be protected from

voltage and current surges.
Bulletin 1753E-001 (Form 522)

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Part I, January 1996

21.1.2 Central office switching equipment shall pass laboratory

tests, simulating the hostile electrical environment, before

being placed in the field for the purpose of obtaining field

experience. There are five basic types of laboratory tests which

shall be applied to exposed terminals in an effort to determine

if the equipment will survive. Figure 3 summarizes these tests

and the minimum acceptable levels of protection for equipment to

pass them.

21.1.3 Two Categories of Surge Tests

21.1.3.1 Current surge tests simulate the stress to which a

relatively low impedance path may be subjected before main frame

protectors break down. Paths with a 100 Hz impedance of 50 ohms

or less shall be subjected to current surges, employing a 10 x

1000 microseconds waveshape as defined in Figure 4. For the

purpose of determining this impedance, arresters which are

mounted within the equipment are to be considered zero impedance.

The crest current shall not exceed 500A; however, depending on

the impedance of the test specimen this value of current may be

lower. The crest current through the sample, multiplied by the

sample's 100 Hz impedance, shall not exceed 1000 volts (V).

Where sample impedance is less than two ohms, crest current shall

be limited to 500A as shown in Figure 5.

21.1.3.2 Sixty Hertz (60 Hz) current-carrying tests should be

applied to simulate an ac power fault which is conducted to the

unit over the cable pairs. The test should be limited to 10

amperes rms at 60 Hz for a period of 11 cycles (0.1835 seconds)

and should be applied longitudinally from line to ground (see

Figures 3 and 6 of this bulletin).

21.1.3.3 AC power service surge voltage tests should be applied

to the power input terminals of ac powered devices to simulate

switching surges or lightning-induced transients on the ac power

system. The test shall employ a 1.2 x 50 microseconds waveshape

with a crest voltage of 2500V. Communications line protectors

may be left in place for this test. Borrowers are urged to

install commercially available surge protectors at the ac service

entrance as part of their COE building program.

21.1.3.4 Voltage surge tests simulate the voltage stress to

which a relatively high impedance path may be subjected before

primary protectors break down and protect the circuit. To assure

coordination with the primary protection while reducing testing

to the minimum, voltage surge tests should be conducted at a 1000

volts with primary arresters removed for devices protected by

carbon blocks, or the +3 sigma dc breakdown of other primary

arresters. Surge waveshape should be 10 x 1000 microseconds.

21.1.3.5 Arrester response delay tests are designed to stress

the equipment in a manner similar to that caused by the delayed
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Part I, January 1996

breakdown of gap type arresters when subjected to rapidly rising

voltages. Arresters shall be removed for these tests, the peak

surge voltage should be the +3 sigma breakdown of the arrester in

question on a voltage rising at 100V per microsecond and the time

for the surge to decay to half voltage shall equal at least the

delay time of the tube, as explained in Figure 7.

21.1.4 Five applications of each polarity for the surge tests

and three for the 60 Hz Current Carrying Test are the minimum

required. All tests should be conducted with not more than 1

minute between consecutive applications in each series of three

or five to a specific configuration so that heating effects will

be cumulative. As not all tests are required in every

application, nonapplicable tests should be omitted. Tests should

be conducted in the following sequence.

21.1.4.1 Current Impulse Test.

21.1.4.2 Sixty Hertz (60 Hz) Current Carrying Test.

21.1.4.3 AC Power Service Impulse Voltage Test.

21.1.4.4 Voltage Impulse Test.

21.1.4.5 Arrester Response Delay Test.

21.1.5 Tests should be applied between each of the following

terminal combinations for all line operating conditions.

21.1.5.1 Line tip to ring.

21.1.5.2 Line ring to ground.

21.1.5.3 Line tip to ground.

21.1.5.4 Line tip to ring tied together to ground.

21.2 Extraordinary Surge Protection: A central office or RST

may be located in an area where ground conditions prevent the

reasonable economic achievement of a low resistance to ground

and/or there exists a greater than average probability of surge

damage. Such an unusually hostile operating environment shall be

recognized and taken into consideration by the bidder in the

engineering and specification of the central office switching

system and line protection. This subject of operating

environment, ground conditions, etc., should be discussed at the

time of technical presentation to assure the owner that adequate

system protection will be provided by the bidder.

21.3 Dielectric Strength: Arresters shall be removed for all

dielectric strength tests. The duration of all dielectric

strength tests shall be at least 1 second. The applied potential

shall equal or exceed the +3 sigma dc breakdown voltage of the
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Part I, January 1996

arrester, provided by the COE manufacturer. Direct current

potentials shall be applied between all line terminals and

equipment chassis and between these terminals and grounded

equipment housings in all instances where the circuitry is dc

open circuit from the chassis, or connected to the chassis

through a capacitor.

21.4 Insulation Resistance: Following the dielectric tests, the

insulation resistance of the installed electrical circuits

between wires and ground, with the normal equipment grounds

removed, shall not be less than 10 megohms at 500 volts dc at

approximately room temperature [68°F (20°C)] and at a relative

humidity of approximately 50 percent. The measurement shall be

made after the meter stabilizes, unless the requirement is met

sooner. Arresters shall be removed for these tests.

21.5 Self-protection

21.5.1 All components shall be of the self-protecting type,

capable of being continuously energized at rated voltage without

injurious results.

21.5.2 The unit equipment shall not be permanently damaged by

accidental short circuits of any duration across either the

central office side tip and ring or the line side tip and ring.

A test is to be made with the unit energized at the highest

recommended voltages.

21.6 Static Discharge: Assemblies subject to damage by static

discharge shall be identified and special handling instructions

shall be supplied.

22. MISCELLANEOUS

22.1 Office Wire: All office wire shall be of soft annealed

tinned copper wire meeting the requirements of ASTM Specification

B 33-91, Standard Specification for Tinned Soft or Annealed

Copper Wire for Electrical Purposes, and of suitable

cross-section to provide safe current carrying capacity and

mechanical strength. The insulation of installed wire, connected

to its equipment and frames, shall be capable of withstanding the

same insulation resistance and dielectric strength requirements

as given in paragraphs 21.3 and 21.4 of this bulletin at a

temperature of 120°F (49°C) and a relative humidity of 90

percent.

22.2 Wire Wrapped Terminals: These terminals are preferred and

where used shall be of a material suitable for wire wrapping.

The connections to them shall be made with a wire wrapping tool

with the following minimum number of successive nonoverlapping

turns of bare tinned copper wire in contact with each terminal.
Bulletin 1753E-001 (Form 522)

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Part I, January 1996

22.2.1 6 Turns of 30 Gauge.

22.2.2 6 Turns of 26 Gauge.

22.2.3 6 Turns of 24 Gauge.

22.2.4 5 Turns of 22 Gauge.

22.3 Protection Against Corrosion: All metal parts of equipment

frames, distributing frames, cable supporting framework, and

other exposed metal parts shall be constructed of corrosion

resistant materials or materials plated or painted to render them

adequately corrosion resistant.

22.4 Screws and Bolts: Screw threads for all threaded securing

devices shall be of American National Standard form in accordance

with Federal Standard H28, Screw-Thread Standards for Federal

Services, unless exceptions are granted to the manufacturer of

the switching equipment. All bolts, nuts, screws, and washers

shall be of nickel-copper alloy, steel, brass or bronze.

22.5 Temperature and Humidity Range: The supplier shall furnish

the operating temperature and humidity ranges of the equipment

being provided in order that adequate heating and cooling may be

supplied (see Items 5.2.1 and 5.2.2 of Part V of this bulletin).

22.6 Stenciling: Equipment units and terminal jacks shall be

adequately designated and numbered. They shall be stenciled so

that identification of equipment units and leads for testing or

traffic analysis can be made without unnecessary reference to

prints or descriptive literature.

22.7 Equipment Frame Design: For newly designed systems,

consideration should be given to the desirability of providing

frames which can be installed in rooms of normal ceiling height

[up to 10 feet (305 cm)]. Where feasible, frames and equipment

units shall be designed for ready portability and high salvage

value.

22.8 Quantity of Equipment Bays: Consistent with system

arrangements and ease of maintenance, space shall be provided on

the floor plan for an orderly layout of future equipment bays

that will be required for anticipated traffic when the office

reaches its ultimate size. Readily accessible terminals shall be

provided for connection to interbay and frame cables to future

bays. All cables, interbay and intrabay (excluding power), if

technically feasible, shall be terminated at both ends by use of

connectors.
Bulletin 1753E-001 (Form 522)

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Part I, January 1996

23. REMOTE SWITCHING TERMINAL (RST)

23.1 General: The RST is a remotely located digital switching

terminal which is placed at a subordinate wire center for

subscriber lines and is a part of the host central office from a

switching standpoint, and has hardware interchangeable with the

host office, except for items that are applicable only to RST

control and associated peripheral equipment. This does not

preclude the use of existing in-service remote units on a new or

upgraded host central office of the latest series generic or

release.

23.2 Span Line: The RST is to be connected to the host central

office via a means compatible with T1 type span lines using a

DS-1 interface. This connection will be for control supervision

and subscriber communication. The RUS equipment specification

for a span line is PE-60.

23.3 Switching

23.3.1 The RST may have its switching functions controlled

either by the host central office stored program control

processors or by local subordinate processors which communicate

with the host office processors.

23.3.2 As long as the connecting span line is intact, the

subscribers served by the RST shall have all features, traffic

capacity, and services including busy verification, available to

all other subscribers in the system.

23.3.3 The RST shall have available an emergency call processing

option which permits calling among all subscribers and from

subscribers to emergency numbers within the RST if control link

connections to the host central office are severed or otherwise

disabled. The RST shall be capable of rerouting normally used

emergency numbers, such as 911, to predetermined line

terminations in this emergency stand-alone operating condition.

This RST emergency call processing option shall be provided only

when specified by the owner in Item 6.1 of Part IV of this

bulletin.

23.4 Subscriber Line Test

23.4.1 Means shall be available on an optional basis to the

maintenance personnel to make subscriber line tests from a common

location for all subscriber lines including the RST.

23.4.2 If tests in paragraph 23.4.1 of this bulletin are not

requested by the owner for a particular installation, a

subscriber loop test set (see paragraph 15.2.3.1 of this

bulletin) shall be supplied at the RST with a means to access all

lines.
Bulletin 1753E-001 (Form 522)

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Part I, January 1996

23.5 Housing: When housed in a building supplied by the owner,

a complete floor plan including ceiling height, power outlets,

cable entrances, equipment entry and travel, type of

construction, and other pertinent dimensions shall be supplied

with this bulletin.

23.6 Power

23.6.1 Chargers: A single charger meeting the requirements of

paragraph 19.3 of this bulletin (with the exception of paragraph

19.3.8 of this bulletin) is required. An additional charger

capable of carrying the full load or a combination of three

chargers each capable of carrying half the load shall be supplied

if redundant chargers are specified in Part IV of this bulletin.

23.6.2 Ringing Equipment Provisioning

23.6.2.1 Ringing sources shall be supplied in duplicate.

23.6.2.2 An exception to the duplicated ringing source

requirement permits nonduplicated ringing source(s) to be

utilized where there is full compliance with the following

service criteria.

23.6.2.2.1 In a remote switching terminal (RST) of 400 or more

equipped lines, a single nonduplicated ringing source failure

shall not cause the complete loss of ringing capability to more

than 100 lines.

23.6.2.2.2 In a remote switching terminal (RST) of less than 400

equipped lines, a single nonredundant ringing source failure

shall not cause the complete loss of ringing capability to more

than 25 percent of the total equipped lines.

23.6.3 Power Converter

23.6.3.1 Power converters required for the purpose of providing

various operating voltages to printed circuit boards or similar

equipment employing electronic components shall be provided in

duplicate with each unit capable of immediately assuming the full

operating load upon failure of a unit.

23.6.3.2 An exception to the duplicate power converter

requirement permits nonduplicated power converter(s) to be

utilized where there is full compliance with the following

criteria.

23.6.3.2.1 The failure of any single nonduplicated power

converter shall not reduce the grade of service of common control

and service circuits to any individual line or trunk by more than

50 percent.
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Part I, January 1996

23.6.3.2.2 The failure of any single nonduplicated power

converter shall not reduce the traffic carrying capacity of any

trunk group or service links to a host office by more than 50

percent.

23.6.3.2.3 In a remote switching terminal (RST) of 400 or more

equipped lines, any single nonduplicated power converter failure

shall not cause a complete loss of service to more than 100

equipped lines.

23.6.3.2.4 In a remote switching terminal (RST) of less than 400

equipped lines, any single nonduplicated power converter failure

shall not cause a complete loss of service to more than 25

percent of the total equipped lines.

23.7 Alarm: Sufficient system alarm points shall be provided

from the RST to report conditions to the host alarm system.

24. RESPONSIBILITIES OF THE BIDDER

24.1 Central Office Layout

24.1.1 The successful bidder shall furnish tentative floor plan

layout drawings showing the arrangement of the equipment and the

dimensions of major equipment units. These drawings shall

include minimum door dimensions and ceiling heights required for

installation, maintenance and ventilation. If requested by the

owner, the floor plan shall be such that the battery, charger,

power board, main distributing frame and wire chief's test

equipment are isolated from the other equipment by a partition.

24.1.2 The layout drawings shall also show provision for the

ultimate capacity of the central office as specified by the

owner.

24.1.3 After approval by the owner of the tentative floor plan,

and within 10 calendar days after approval of the contract by the

Administrator, the owner shall furnish the bidder the necessary

data on the actual floor plan. Within 20 calendar days after

receiving the necessary building data, the bidder shall then

supply floor plan drawings showing exact locations of all

equipment, both initial and ultimate, including points where

connection to commercial power are required, with voltage and

wattage indicated at each point. Within 20 calendar days after

receiving the floor plan drawings from the bidder, the owner

shall approve these drawings or take the necessary steps to have

the drawings changed to meet his approval. The layout planning

must be so coordinated between the owner and the bidder as not to

delay the scheduled equipment installation date.

24.2 Shipment of Main Distributing Frame (MDF): The bidder

shall ship the MDF equipment, with all necessary instructions to
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Part I, January 1996

permit its installation by the owner, at the time requested by

the owner in writing, provided such time is not earlier than 90

days prior to the date specified for the shipment of the rest of

the central office equipment. If the owner or the owner's agent

installs the main distributing frame, the owner shall assume the

responsibility and the expense of proper installation according

to information furnished by the bidder.

24.3 Drawings and Printed Material

24.3.1 The bidder shall supply instructional material for each

exchange involved at the time of delivery of the equipment. It

is not the intent of this bulletin to require system

documentation necessary for the repair of individual circuit

boards. The bidder shall supply three complete sets of legible

drawings, each set to include all of the following drawings and

documentation:

24.3.1.1 A floor plan showing exact dimensions and location of

each equipment frame or item to a convenient scale;

24.3.1.2 A block schematic drawing showing the various equipment

components in the system, and their identifying circuit number

(e.g., MDF, line circuits, memory, trunks, etc.);

24.3.1.3 Drawings of major equipment items such as frames, with

the location of major component items of equipment shown;

24.3.1.4 Individual functional drawings for electrical circuits

in the system;

24.3.1.5 A detailed description of the operation of each circuit

down to a circuit package level;

24.3.1.6 Wiring diagrams indicating the specific method of

wiring used on each item of equipment and interconnection wiring

between items of equipment;

24.3.1.7 Sufficient software documentation to maintain and

service the system, including drawings showing principal aspects

of the software architecture;

24.3.1.8 Individual maintenance drawings covering each equipment

item that contains replaceable parts, appropriately identifying

each part by name and part number, or, complete ordering

instructions for all replaceable parts if individual item

drawings are not provided; and

24.3.1.9 Job drawings including all drawings that are individual

to the particular office involved, such as main frame, power

panel, test board, etc.

24.3.2 The following information shall also be furnished:
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Part I, January 1996

24.3.2.1 Complete index of the required drawings;

24.3.2.2 Explanation of electrical principles of operation of

the overall switching system;

24.3.2.3 List of tests which can be performed with each piece of

test equipment furnished, and explanation of the method of

performing each test;

24.3.2.4 Sample of each form recommended for use in keeping

records of tests;

24.3.2.5 Criteria for analyzing results of tests and determining

appropriate corrective action;

24.3.2.6 General notes on the methods of isolating equipment

faults to specific printed circuit cards in the equipment;

24.3.2.7 List of typical troubles which might be encountered,

together with general indications as to the probable location of

each trouble;

24.3.2.8 Special office grounding requirements;

24.3.2.9 A site specific central office ground system acceptance

checklist that is consistent with industry practice; and

24.3.2.10 A site specific layout of the master ground bar (MGB)

showing assignment of P, A, N, and I equipment areas.

24.4 Distributing Frame Wire: The bidder shall provide

sufficient tinned copper conductor distributing frame wire for

the initial installation. The insulation of this wire shall be

such that it will not support combustion. The insulation shall

have good abrasion resistance and cut-through properties, exhibit

good solder heat resistance, and be suitable for wire wrap

connections or insulation displacement connections.

24.5 Technical Assistance Service: A technical assistance

service shall be made available to assist the owner and its

maintenance personnel on a 24-hour, 7 days a week basis. There

is to be assistance available for both hardware and software

problems. The necessary interface devices shall be supplied by

the bidder.

24.6 Spare Parts

24.6.1 The spare parts bid price shall be based upon the

required quantities of spares shown in Item 6.2 of Part V of this

bulletin, and shall be added to the base bid for comparison

purposes in awarding the bid. It is the supplier's

responsibility to provide all spares required by this bulletin.
Bulletin 1753E-001 (Form 522)

Page I-60

Part I, January 1996

If the supplier neglects to list certain spare parts in Item 6.2

of Part V of this bulletin, but they are necessary to comply with

this bulletin, they shall be provided by the supplier at no

additional cost to the owner.

24.6.1.1 "Units" are defined as user replaceable components used

in the central office equipment. "Spare Parts" are direct

replacements for units. Spare parts are necessary for the

maintenance and diagnostic operations where the suspected faulty

unit may be removed and a spare part substituted in anticipation

that the trouble will be cleared.

24.6.1.2 Examples of units for which spare parts should be

furnished are printed circuit cards; circuit pack assemblies;

fuses; and power supplies.

24.6.1.3 Spare parts are not required as part of this addendum

for items such as connectorized cables, nuts, bolts, and similar

hardware; nor for items which can be obtained from sources other

than the bidder such as battery cells, chargers, powerboards,

magnetic tape transport assemblies, disk drives, ringing

machines, recorded announcement machines, loop extenders and

voice frequency repeaters, fire bars, teletypewriters, and video

monitors.

24.6.1.4 When 100 or more like units are used in the hosts and

RST's to be bid, the quantity of spares to be furnished is

determined by multiplying the total number of like units in the

contract by .05 or .03, as applicable, and rounding off to the

next lowest integer. For example, 119 Class 1 units require five

spares; 120 require six.

24.6.1.5 When alternates are required, the price of the spare

parts for the alternates shall be included with the price of the

alternate.

24.6.1.6 For equipment in which the line cards consist of a

number of plug-in "daughter" boards on a "mother" board, the line

card is defined as the "daughter" board unit. In a similar

manner for those designs which have line cards backed up by a

"control card," the "control card" is not, by definition, a line

card.

24.6.1.7 The quantities of spare parts determined in paragraph

24.6.6 of this bulletin are a minimum quantity. The bidder may

add quantities of spare parts to bring the number of spare parts

up to the bidder's list of spare parts necessary for proper

operation in the field.

24.6.2 A Class 1 unit does not have automatic transfer to a

redundant or standby pool of identical units, and provides any

function for 24 or more lines or trunks or for all trunks in a
Bulletin 1753E-001 (Form 522)

Page I-61

Part I, January 1996

group. Nonredundant digital trunk interfaces are included in

this category.

24.6.3 A Class 2 unit has automatic transfer to a redundant or

standby pool of identical units, and provides any function for 24

or more lines or trunks or for all trunks in a group. Redundant

digital trunk interfaces and units of a redundant stored program

processor are included in this category.

24.6.4 A Class 3 unit does not have automatic transfer to a

redundant or standby pool of identical units and provides any

function for no more than 23 lines or trunks or for less than all

trunks in a group. Nonredundant analog trunks are included in

this category. Excluded from this category are line cards, which

are in Class 4.

24.6.5 A Class 4 unit has automatic transfer to a redundant or

standby pool of identical units and provides any function for no

more than 23 lines or trunks or for less than all trunks in a

group. Also, any line cards are in Class 4.

24.6.6 The spare parts for all of the hosts and the RST's

included in this contract shall be provided as follows:

Quantity of Units used in

the CO's & RST's To Be Bid

Required Quantity of Spares

By Class of Unit

Class ---> 1234

 1 through 9 1100

 10 through 24 2210

 25 through 49 3220

 50 through 99 4320

100 or More 5% 3% 3% 0

24.6.7 As a part of the response to the bid, the supplier shall

furnish a list of units used by class and a list of spare parts

to be furnished with this contract. This list shall be placed in

Item 6.2 of Part V of this bulletin for only one of the host

specifications included in the entire contract.

24.7 Environmental Requirements: The bidder shall specify the

environmental conditions necessary for safe storage and

satisfactory operation of the equipment being bid. If requested,

the bidder shall assist the owner in planning how to provide the

necessary environment for the equipment.

24.8 Unit Costs for Cost Separation Purposes: The successful

bidder shall present a cost breakdown of the central office

equipment on a discrete element basis 90 days after installation

completion. This shall include the various frames, switching and

transmission components, and software.
Bulletin 1753E-001 (Form 522)

Page I-62

Part I, January 1996

24.9 Single-point Grounding System Acceptance: Qualified

representatives of the central office system supplier and the

owner are to conduct a thorough joint acceptance audit of the

grounding system prior to the central office being placed into

service. A grounding system acceptance checklist provided by

RUS, which is consistent with standard industry practice, will be

used in conducting this audit. All required grounding system

corrections are to be made prior to placing the central office

system into full service operation. The successful completion of

this grounding system audit will constitute an acceptance on the

part of both parties, the owner and the central office supplier

(refer to paragraph 1.5 of Part II of this bulletin, and Part VI

of this bulletin).
Bulletin 1753E-001 (Form 522)

Page I-63

Part I, January 1996

Figure 1

Measuring the Effects of Low Frequency Induction

Notes:

1. 900 ohm termination, C-message weighting, hold coil off

2. SNC Noise Choke 35 W, or equivalent

3. Test at 0.020 Adc and 0.070 Adc

4. 2 ± 0.001 microfarad, 150 Vdc
Bulletin 1753E-001 (Form 522)

Page I-64

Part I, January 1996

Figure 2

Charger Noise Test

The manufacturer may elect to eliminate the capacitor C from the

measurement.

A. Capacitance in μF = 30,000 μF per ampere-hour per

cell. For example, 25 cells at 100 ampere-hour would

be equivalent to a capacitance of:

(30,000 x 100)/25 = 120,000 μF

B. The value of the resistive load R is determined by the

nominal battery voltage in volts divided by the full

load rating in amperes. For example, for a 48 volt

battery and a full load current of 24 amperes, the

load resistance R is 48/24 = 2 ohms of appropriate

power handling capacity.
Figure 3

Summary of Electrical Requirements and Tests

Test Application Criteria Peak Voltage

Or Current

Surge

Waveshape

No. of Applications& Max. Time Between

CurrentSurge

Low Impedance PathsExposed to Surges

500A or Lesser

Current(See Fig. 5)

10x1000 μs 5 each Polarity at 1 minute

intervals

60 HzCurrentCarrying

High or Low Impedancepaths Exposed toSurges

10A rms or

LesserCurrent(See Fig. 6)

 11 cycles

of 60 Hz(0.183 Sec.)

3 each Polarity at1 minute intervals

AC PowerServiceSurgeVoltage

AC Power ServiceConnection

2500V or +3 σ

clamping V ofarresteremployed at10kV/μs

1.2x50 μs 5 each Polarity at 1 minute

intervals

VoltageSurge

High Impedance PathsExposed to Surges

 1000V or

+3 σ dcbreakdown ofarresteremployed

10x1000 μs Same 

ArresterResponseDelay

Paths protected byarresters, such asgas tubes, withbreakdown dependenton V. rate of rise.

 +3 σbreakdown

of arresteremployed at100V/μs of

rise

100V/μs

rise decayto 1⁄2 V.

in tube’s

delay time

Same 

Part I, January 1996
Bulletin 1753E-001 (Form 522)

Page I-66

Part I, January 1996

Figure 4

Explanation of Surge Waveshape

Surge Waveshape is defined as follows:

Rise Time x Time to Decay to Half Crest Value

(For example, 10 x 1000 μs)

Notes: T1 = Time to determine the rate of rise. The rate

of rise is determined as the slope between 10%

and 90% of peak voltage or current.

T2 = Time to 50% of peak voltage (decay to half

value).
Bulletin 1753E-001 (Form 522)

Page I-67

Part I, January 1996

Figure 5

Current Surge Test

VL = Not to exceed 1000V

VB = Charging Voltage

Z100 = Test Specimen Impedance to be measured at 100 Hz.

RP = Parallel Resistance (Waveshape)

RS = Series Resistance (Current Limiting)

Z100 RS RP VB ________________________________________

0 5 _ 2500

1 4 _ 2500

2 3 _ 2500

3 2 _ 1670

4 1 _ 1250

5 0 _ 1000

7.5 0 15 1000

10 0 10 1000

15 0 7.5 1000

20 0 6.7 1000

25 0 6.25 1000

30 0 6 1000

40 0 5.7 1000

50 0 5.5 1000
Bulletin 1753E-001 (Form 522)

Page I-68

Part I, January 1996

Figure 6

60 Hz Current Surge Test

V - 700 Volts RMS (Approximately 1000V Peak).

Z60 - Test specimen impedance to be measured at 60 Hz.

RS - Series Resistance (current limiting) in each

side of line. (Source impedance never less

than 50 Ω longitudinal.)

Z60 Hz RS ______ ___

0 140

10 120

20 100

50 100

Over 50 100
Bulletin 1753E-001 (Form 522)

Page I-69

Part I, January 1996

Figure 7

Explanation of Arrester Response Delay Time

The delay time is that period of time when the potential across

an arrester exceeds its dc firing level.
[Page left intentionally blank]
Bulletin 1753E-001 (Form 522)

Page II-1

Part II, January 1996

PART II

INSTALLATION

1. INSTALLATION: The following responsibilities apply to the

central office equipment installation and Remote Switching

Terminal (RST) installations, unless otherwise noted.

1.1 Responsibilities of Owner: The owner shall:

1.1.1 Allow the bidder and its employees free access to the

premises and facilities at all hours during the progress of the

installation;

1.1.2 Take such action as necessary to ensure that the premises

are dry and free from dust and in such condition as not to be

hazardous to the installation personnel or the material to be

installed (not required for an RST installed in a self-contained

environmentally controlled cabinet);

1.1.3 Provide heat or air conditioning when required and general

illumination in rooms in which work is to be performed or

materials stored (not required for an RST installed in a

self-contained environmentally controlled cabinet);

1.1.4 Provide suitable openings in buildings to allow material

to be placed in position (not required for an RST installed in a

self-contained environmentally controlled cabinet);

1.1.5 Provide the necessary conduit and commercial and dc-ac

inverter output power to the locations shown on the approved

floor plan drawings; provide 120 volts, 60 Hz commercial power

equipped with a secondary arrester and a reasonable number of

outlets for test, maintenance and installation equipment; provide

suitable openings or channels and ducts for cables and

conductors, from floor to floor and from room to room; provide an

acceptable central office grounding system and at a ground

resistance level that is reasonable for office site conditions

(not required for an RST installed in a self-contained

environmentally controlled cabinet);

1.1.6 Provide the necessary wiring, central office grade ground

and commercial power service, with a secondary arrester, to the

location of an exterior RST installation based on the voltage and

load requirements furnished by the bidder;

1.1.7 Test at the owner's own expense all lines and trunks for

continuity, leakage and loop resistance and ensure that all lines

and trunks are suitable for operation with the central office

equipment specified;
Bulletin 1753E-001 (Form 522)

Page II-2

Part II, January 1996

1.1.8 Make alterations and repairs to buildings necessary for

proper installation of material, except to repair damage for

which the bidder or its employees are responsible;

1.1.9 Connect outside cable pairs on the distributing frame and

run all line and trunk jumpers (those connected to protectors);

1.1.10 Furnish all trunk, line, and party assignment information

to permit the bidder to program the data base memory within a

reasonable time prior to final testing;

1.1.11 Release for the bidder's use such portions of the

existing plant as are necessary for the proper completion of such

tests as require coordination with existing facilities including

facilities for T1 span lines with properly installed repeaters

between the central office and the RST installations;

1.1.12 Make prompt inspections as it deems necessary when

notified by the bidder that the equipment, or any part of the

equipment, is ready for acceptance;

1.1.13 Provide and install adequate fire protection apparatus,

including one or more fire extinguishers or fire extinguishing

systems of the gaseous type that has low toxicity and effect on

equipment; and

1.1.14 Provide necessary access ports for cable, if underfloor

cable is selected.

1.2 Responsibilities of Bidder: The bidder shall:

1.2.1 Allow the owner and its representatives access to all

parts of the buildings at all times during the installation;

1.2.2 Obtain the owner's permission before cutting into or

through any part of the building structure such as girders,

beams, concrete or tile floors, partitions or ceilings (not

applicable to the installation of lag screws, expansion bolts,

and similar devices used for fastening equipment to floors,

columns, walls and ceilings);

1.2.3 Be responsible for reporting to the owner any damage to

the building which may exist or may occur during its occupancy of

the building, repairing all damage to the building due to

carelessness of the bidder's workforce, and exercising reasonable

care to avoid any damage to the owner's property;

1.2.4 Consult with the owner before cutting into or through any

part of the building structure where the fireproofing or moisture

proofing may be impaired;
Bulletin 1753E-001 (Form 522)

Page II-3

Part II, January 1996

1.2.5 Take necessary steps to ensure that all fire fighting

apparatus is accessible at all times and all flammable materials

are kept in suitable places outside the building;

1.2.6 Not use gasoline, benzene, alcohol, naphtha, carbon

tetrachloride or turpentine for cleaning any part of the

equipment;

1.2.7 Install the equipment in accordance with the

specifications for the office;

1.2.8 Run all jumpers, except line and trunk jumpers (those

connected to protectors);

1.2.9 Establish and update all data base memories with

subscriber and trunk information as supplied by the owner until

an agreed turnover time;

1.2.10 Give the owner notice of completion of the installation

at least 1 week prior to completion;

1.2.11 Permit the owner or its representative to conduct tests

and inspections after installation has been completed in order

that the owner may be assured that the requirements for

installation are met;

1.2.12 Allow access, before turnover, by the owner or its

representative, upon request, to the test equipment which is to

be turned over as a part of the office equipment, to permit the

checking of the circuit features which are being tested and to

permit the checking of the amount of connected equipment to which

the test circuits have access;

1.2.13 Make final charger adjustments using the manufacturer's

recommended procedure;

1.2.14 Notify the owner promptly of the completion of work of

the central office, or such portions as are ready for inspection;

1.2.15 Correct promptly all defects for which the bidder is

responsible;

1.2.16 Provide the owner with one set of marked prints, or

strapping prints, showing which of the various options and

figures are in use on each switching system as specified in

paragraph 24.3.1 of this bulletin;

1.2.17 Place the battery in service in compliance with the

recommendations of the battery manufacturer; and

1.2.18 Furnish the owner with a record of the cell voltages and

specific gravity readings made at the completion of the
Bulletin 1753E-001 (Form 522)

Page II-4

Part II, January 1996

installation of the switching system and before it is placed in

commercial service.

1.3 Installation Requirements

1.3.1 All work shall be done in a neat, workmanlike manner.

Equipment frames or cabinets shall be correctly located,

carefully aligned, anchored and firmly braced. Cables shall be

carefully laid with sufficient radius of curvature and protected

at corners and bends to ensure against damage from handling or

vibration. Exterior cabinet installations for RST's shall be

made in a permanent, eye-pleasing manner.

1.3.2 All multiple and associated wiring shall be continuous,

free from crosses, reverses and grounds and shall be correctly

wired at all points.

1.3.3 An inspection shall be made by the owner or its

representatives prior to performing operational and performance

tests on the equipment. However, this inspection shall be made

after all installing operations which might disturb apparatus

adjustments have been completed. The inspection shall be of such

character and extent as to disclose with reasonable certainty any

unsatisfactory condition of apparatus or equipment. During these

inspections, or inspections for apparatus adjustments, or

soldering, or in testing of equipment, a sufficiently detailed

examination shall be made throughout the portion of the equipment

within which such condition is observed, or is likely to occur,

to disclose the full extent of its existence, where any of the

following conditions are observed:

1.3.3.1 Apparatus or equipment units failing to compare in

quantity and code with that specified for the installation;

1.3.3.2 Apparatus or equipment units damaged or incomplete;

1.3.3.3 Apparatus or equipment affected by rust, corrosion or

marred finish; or

1.3.3.4 Other adverse conditions resulting from failure to meet

generally accepted standards of good workmanship.

1.4 Operational Test Requirements

1.4.1 Operational tests shall be performed on all circuits and

circuit components to ensure their proper functioning in

accordance with appropriate applicable documents supplied by the

bidder.

1.4.2 A sufficient quantity of overall tests shall be made to

ensure proper operation of all specified features.
Bulletin 1753E-001 (Form 522)

Page II-5

Part II, January 1996

1.4.3 A sufficient quantity of locally originating and incoming

calls shall be made to prove the switching system can accept and

process calls to completion.

1.5 Grounding System Audit

1.5.1 A grounding system audit shall be performed to ensure that

a viable single-point grounding system is in place prior to the

time the switching system is placed into full service operation.

It is suggested that such an audit be conducted at the time the

switching system is ready for turnover to the owner.

1.5.2 This single-point grounding system audit is to be

conducted by authorized representatives of the supplier and

owner, and with the RUS general field representative

participating at his discretion.

1.5.3 The single-point grounding system audit is to be conducted

using the checklist contained in Part VI of this bulletin.

1.5.4 Part VI of this bulletin shall be the principal

single-point grounding system audit guideline document. A

supplemental checklist may be prepared and provided by the

switching system supplier which recognizes unique grounding

requirements related to their particular switching system. The

scope of this supplier checklist is to be confined to unique and

specific switching system requirements only. Acceptable supplier

supplemental grounding checklist must have prior approval of and

be on file with the Central Office Equipment Branch of the

Telecommunications Standards Division of RUS.

1.5.5 It is the responsibility of the central office supplier to

ensure that the grounding system evaluation criteria contained in

the combination of the Part VI checklist of this bulletin and

their optional supplemental checklist adequately fulfill

requirements for warranty coverage.

1.5.6 All deficiencies in the single-point grounding system are

to be corrected prior to the switching system being placed into

full service operation. Exceptions are permitted only by mutual

agreement of the owner and supplier and with written approval of

the RUS general field representative.

1.5.7 The acceptance statement facesheet of the audit checklist

in Part VI of this bulletin shall be signed by authorized

representatives of the supplier and owner to indicate mutual

approval of the single-point grounding system. Copies of all

completed grounding system audit documents are to be provided to

the supplier, owner and appropriate RUS telephone program

regional offices.
[Page left intentionally blank]
Bulletin 1753E-001 (Form 522)

Page III-1

Part III, January 1996

PART III

SPECIFICATION FOR DIGITAL, STORED PROGRAM CONTROLLED CENTRAL

OFFICE EQUIPMENT DETAILED REQUIREMENTS (HOST)

(Information to be Supplied by Owner)

Telephone Company

Name ___________________________________________________________

Location

_________________________________________________________________

Central Office Name (By Location)

Town ______________ County ____________ State _____________

 ________ Attended ______ Unattended _________ Remotes

1. GENERAL

1.1 Notwithstanding the bidder's equipment lists, the equipment

and materials furnished by the bidder must meet the requirements

of Parts I, III, and IV of this bulletin.

1.2 Part I of this bulletin cover the minimum general

requirements for digital, stored program controlled central

office switching equipment.

1.3 Part II of this bulletin covers requirements for

installation, inspection, and testing when such service is

included as part of the contract.

1.4 Parts III and IV of this bulletin cover the technical data

for application engineering and detailed equipment requirements

insofar as they can be established by the owner. These parts are

to be filled in by the owner.

1.5 Part V of this bulletin covers detailed information on the

switching network equipment and the common control equipment, and

information as to system reliability and heavy traffic delays as

proposed by the bidder. This part is to be filled in by the

bidder and must be presented with the bid.

1.6 Part VI of this bulletin is the single-point grounding

system audit checklist.
Bulletin 1753E-001 (Form 522)

Page III-2

 Office Name

 (By Location)________________

Part III, January 1996

2. NUMBERING SCHEME

2.1 This office shall be arranged to serve the following area

and office code(s):

 ____________________

 ____________________

 ____________________

 ____________________

 If more than one code is to be served, discrimination shall

be determined by the following:

 Number Translation ___

 Separate Trunk Groups ___

 Both (Explain in Item 16, Part III) ___

2.2 This office shall be arranged to provide EAS service to the

following:

Connecting Office Code Connecting Office Code 

_________________ _____ _________________ ______

_________________ _____ _________________ ______

_________________ _____ _________________ ______

_________________ _____ _________________ ______

2.2.1 Seven digits shall be dialed for all local and EAS calls.

2.3 Additional dialing procedures to be provided include the

following:

Feature Required

Station Paid Toll (Including Coin):

Home Numbering Plan Area (HNPA)

"1" + 7 Digits ___

"1" + 10 Digits ___

Other (Explain in Item 16, Part III) ___

Foreign Numbering Plan Area (FNPA)

"1" + 10 Digits ___

Other (Explain in Item 16, Part III) ___
Bulletin 1753E-001 (Form 522)

Page III-3

 Office Name

 (By Location)________________

Part III, January 1996

10XXX Dialing to Interexchange Carriers:

 Name Access Code

 ________________________ ___________

 ________________________ ___________

 ________________________ ___________

 ________________________ ___________

Feature Required

Person, Special (Including Coin):

HNPA - "0" + 7 Digits ___

"0" + 10 Digits ___

FNPA - "0" + 10 Digits ___

Other (Explain in Item 16, Part III) ___

Directory Assistance:

HNPA Local - 411 ___

"1" + 411 ___

HNPA Toll "1" + 555-1212 ___

FNPA Toll "1" + NPA + 555-1212 ___

IDDD:

Operator Serviced 01 ___

Station-Station 011 ___

Other Service Codes Number to be Dialed

Wire Chief ___________________

Repair Service ___________________

Business Office ___________________

Emergency Calls to 911 Lines ___________________

Emergency Calls to 911 Trunks ___________________

Time ___________________

Weather ___________________

100 Test Line ___________________

102 Test Line ___________________

105 Test Line ___________________

Other (Explain in Item 16,

Part III) ___________________
Bulletin 1753E-001 (Form 522)

Page III-4

 Office Name

 (By Location)________________

Part III, January 1996

2.4 Assistance calls are answered: (Check appropriate items)

2.4.1 At the operator office in ___________________________

2.4.1.1 By means of the regular interoffice toll trunks ___

2.4.1.2 By means of the regular interoffice EAS trunks ___

2.4.1.3 By means of a separate special service

 trunk group ___

2.4.1.4 Locally ___

Explain:

3. OFFICE CLOCK

3.1 This office is to be slave clock synchronized with another

office:

 ___ Yes ___ No

(Explain details in Part III, Item 16 if "Yes".)

3.2 This office is to be a master clock office to provide

synchronization timing for other offices:

 ___ Yes ___ No

(Explain details in Part III, Item 16 if "Yes".)

4. INTEROFFICE TRUNKING DIAGRAM

4.1 A sketch showing relative location of exchanges, RST's, and

number of circuits shall be included, also the office and area

codes of the direct trunk points. The diagram should indicate

whether toll or EAS trunk groups are "High Usage" or "Final."

Alternate routes should be included. Indicate whether the trunk

termination is direct digital or analog.
 Office Nam

 (By Locati

5. TRANSLATOR FUNCTION CHART

First Route Alternate 

Called Point Subscriber Dials Translator Action Send Translator Act

Deletes Prefixes Deletes Pref

Part III, January 1996
 Office Name

 (By Location

6. LINE CIRCUIT REQUIREMENTS (Includes all lines associated with RST’s)6.1 Types of Lines

No. of Lines

Both 

Local

Service Only

Local &

EAS Service

No. 

A

6.1.1 Individual – Flat Rate __________ ________ ___6.1.2 Individual – Message Rate __________ ________ ___6.1.3 Pay Station 6.1.4 Telephone Company Official Lines 6.1.5 Wire Chief6.1.6 911 Emergency Service Bureau Lines 6.1.7 Number Hunting PBX Groups:

Number Direct Restricted Type

Of LinesIn Group

No. ofGroups

In

Dial*

Service

at COE

Ground

Start

Loop

Start

_______ ______ _____ _______ _____ _____ __________ ________ __________ ______ _____ _______ _____ _____ __________ ________ __________ ______ _____ _______ _____ _____ __________ ________ __________ ______ _____ _______ _____ _____ __________ ________ __________ ______ _____ _______ _____ _____ __________ ________ ___

Part III, January 1996

 *Furnish translation information under item 5.
Bulletin 1753E-001 (Form 522)

Page III-7

 Office Name

 (By Location)________________

Part III, January 1996

6.1.8 WATS Lines (Give details in Part III, Item 16)

 Number of Inward WATS Lines ____________

 Number of Outward WATS Lines ____________

6.1.9 Special Lines Required ____________ (Explain in

 Part III, Item 16)

6.1.10 Total Number of Lines Required

 Host __________ (Incl. DDI Concentrator Lines)

 RST 1 __________

 RST 2 __________

 RST 3 __________

 TOTAL __________

6.1.11 Total Directory Numbers Required ____________

 (Including RST's)(see Item 7.1, Part III)

6.1.12 Pay Station

 Type _________________

 New ____ Reused ____

 (Describe in Item 16, Part III)

6.1.13 Line Concentrator

6.1.13.1 Supplied by Owner (see Item 16, Part III, for details)

 ____ Yes ____ No

6.1.13.2 Supplied by Bidder (If "Yes", attach RUS Form 397g,

Performance Specification for Line Concentrators)

 ____ Yes ____ No

6.2 Data on Lines Requiring Range Extension

6.2.1 Number of non-pay station lines having a loop resistance,

including the telephone set, as follows:

 No. of Lines

 1901 - 3200 ohms ____________

 3201 - 3600 ohms ____________
Bulletin 1753E-001 (Form 522)

Page III-8

 Office Name

 (By Location)________________

Part III, January 1996

6.2.2 Number of pay station lines having loop resistance,

excluding the telephone set, greater than:

 No. of Lines

 1200 ohms (For Prepay) ____________

 1000 ohms (For Semi-Postpay ____________

 Operation)

6.2.3 Range extension equipment is to be provided:

6.2.3.1 Loop Extenders: Total Quantity ____________

 By Bidder - Quantity ____________

 By Owner - Quantity ____________

 (Explain in Item 16, Part III)

6.2.3.2 VF Repeaters: Total Quantity _______________

 By Bidder - Quantity ____________

 (Bidder must have information on loading and cable size.)

 By Owner - Quantity ____________

 (Explain in Item 16, Part III)

6.2.3.3 Range extension may be furnished as an extended range

line circuit at the option of the supplier. If this option is

used, the quantities of loop extenders and VF repeaters will be

different from the quantities listed above (see Item 6.1,a, Part

V).

 ____Yes ____No
Bulletin 1753E-001 (Form 522)

Page III-9

 Office Name

 (By Location)________________

Part III, January 1996

7. TRAFFIC DATA - LINE ORIGINATING AND TERMINATING TRAFFIC

7.1 Originating Line Traffic - Estimated per Busy Hour (Includes

all lines associated with RST's):

 (a) (b) (axb)

 CCS per No. of No. of

 Main Main Total Lines

 Station Stations CCS Required(1)

Ind. - Res. _______ ________ ___ ___________

Ind. - Bus. _______ ________ ___ ___________

Special Lines _______ ________ ___ ___________

Pay Station _______ ________ ___ ___________

Telco Official _______ ________ ___ ___________

Wire Chief _______ ________ ___ ___________

No. Htg. or PBX _______ (2) _______(3) ___ ___________ WATS _______ ________ ___ ___________

Data Service _______ ________ ___ ___________

911 Emerg. Service _______ ________ ___ ___________

 TOTAL ________ ___ _________(4)

 (c) (d) (e)

7.2 Average Originating CCS per Line per Busy Hour

 (d)/(e) =______/______=_______ CCS/Line

This office shall be engineered to handle an initial average

originating busy hour traffic of______CCS per line. It is

anticipated that the average originating busy hour traffic will

increase to______CCS per line.

 Originating Traffic Attributed to Host

Only______CCS/Line_______________

________________________

(1) See Part III, Item 6.1. (2) This figure is the CCS per PBX trunk. (3) This figure is the number of PBX trunks. (4) This is the total number of line equipments required. The

number to be provided will be determined by the

equipment design of the system of the selected bidder.

See Part III, Item 3.1.1.2.
Bulletin 1753E-001 (Form 522)

Page III-10

 Office Name

 (By Location)________________

Part III, January 1996

7.3 Terminating Traffic - Estimated CCS per Busy Hour

It is assumed that the total CCS for terminating traffic is the

same as for originating traffic. Since digital switch networks

are on a terminal per line basis, the terminating CCS per line

will be the same as the originating CCS per line as shown in Item

7.2, Part III.

 Terminating Traffic Attributed to Host Only______CCS/Line

7.4 Percent of Pushbutton Lines _______

7.5 Anticipated Ultimate Capacity (20 years)

7.5.1 Subscriber Lines

 Host __________ (Incl. DDI Concentrator Lines)

 RST 1 __________

 RST 2 __________

 RST 3 __________

 TOTAL __________
Bulletin 1753E-001 (Form 522)

Page III-11

 Office Name

 (By Location)________________

Part III, January 1996

8. TRUNK CIRCUIT REQUIREMENTS

8.1 Interoffice Trunking

8.1.1 Trunking Requirements

1. Connecting Office

2. Use of Trunk

3. Trk. Grp. Ntwk. Connection(1)

4. Quantity Equipped

5. Ultimate % Growth

6. CCS Capacity

7. Direction

8. No. Digits Dialed

9. No. Digits Outpulsed

10. No. Digits Inpulsed

11. Type Signaling

12. Type Pulsing

13. Carrier Type (2-Wire)

14. Carrier Type (4-Wire)

15. Physical

16. Repeat Coils(2)

17. DX Signaling Set

18. Other Type Signaling

19. Delay Dial

20. Direct Digital Interface

21. a. Feature Group B

b. Feature Group C

c. Feature Group D

________________________

(1) Designation of trunk group network connection involves

the following categories:

IC - Direct Inter-LATA Connecting Trunk = (IC/POP)

TC - Tandem Connecting Trunks

IT - Intertandem Connecting Trunks

IL - Intra-LATA Connecting Trunks

TIC - Tandem Inter-LATA Connecting Trunks

Misc. - Intercept, Busy Verification, etc.

(2) Omit repeating coils for carrier derived trunks.
Bulletin 1753E-001 (Form 522)

Page III-12

 Office Name

 (By Location)________________

Part III, January 1996

8.1.2 For 4-Wire Carrier, the 7dB and 16dB Pads

Total Quantity _______________

By Bidder Quantity _______________

By Owner Quantity _______________

Refer to the attached information regarding connecting company

trunk circuit drawing numbers and name of manufacturer.

8.2 Switched Traffic Data

8.2.1 Originating Traffic

Type CCS

H.T.

Secs. BHC

No. of

Digits

Outpulsed

Sender

Sig.

Mode Remarks

Toll "0"- (1)

Toll "0"+7(1)(2)

Toll "0"+10(1)(2)

Toll S-S "1"+7(2)

Toll S-S "1"+10(2)

Toll Other

Special Service

Intercept

Intraoffice

EAS

EAS

EAS

Tandem

Tandem

Tandem

911 Emerg. Service

TOTAL

____________________

(1) PPCS traffic assumed to be divided 20 percent "0"-

and 80 percent "0"+ if unknown.

(2) Toll calls assumed to be divided two-thirds 7 digits

and one-third 10 digits.
Bulletin 1753E-001 (Form 522)

Page III-13

 Office Name

 (By Location)________________

Part III, January 1996

Busy Hour Attempts = BHC Total x 1.4 = _________

8.2.2 Terminating Traffic

Type

CCS

H.T.

Secs. BHC

No. of

Digits

Inpulsed

Receiver

Sig.

Mode Remarks

Toll Compl.

Test & Ver.

Intraoffice

EAS

EAS

EAS

Tandem

Tandem

Tandem

TOTAL

9. CHECKLIST OF FEATURES REQUIRED

9.1 Alternate Routing ___

 (Explain in Item 16, Part III)

9.2 Data Service ___

 (Explain in Item 16, Part III)

9.3 This office shall be:

9.3.1 End Office Only ___

9.3.2 End Office and Intermediate Tandem ___

 (Explain in Item 16, Part III)

9.3.3 End Office and Access Tandem ___

 (Explain in Item 16, Part III)
Bulletin 1753E-001 (Form 522)

Page III-14

 Office Name

 (By Location)________________

Part III, January 1996

9.4 Billing Data

Trunk

Send ANI

Feature Group Store Billing Data

Group B C D AMA System Pollable

System

9.4.1 This office

only

9.4.2 Trunks from

Tributaries

9.4.3 Local Message Detail Recording:

9.5 Pollable Systems

9.5.1 Polling device to be provided on this contract

 ___ Required ___ Not Required

 (Provide details in Item 16, Part III)

9.5.2 Pollable system to be backed up by tape or disc standby

 ___ Required ___ Not Required

9.6 AMA Format

9.6.1 Bellcore Format

 ___ Required ___ Not Required

 (Provide details in Item 16, Part III)
Bulletin 1753E-001 (Form 522)

Page III-15

 Office Name

 (By Location)________________

Part III, January 1996

10. MISCELLANEOUS OPERATING FEATURES

10.1 Busy Verification

10.1.1 By dedicated trunk from toll operator:

10.1.1.1 One-Way, Inward ___

10.1.1.2 Two-Way (Busy verification inward, intercept

 outward) ___

10.1.2 By prefix digit over intertoll trunk ___

 (Indicate digit(s) dialed) __________

10.1.3 Access by Switchman

10.1.3.1 Dedicated Trunk ___

10.1.3.2 Multiple of Operator Trunk ___

10.2 Intercept Facilities

10.2.1 Vacant code, disconnected number, and unassigned number

intercept shall be: (Check One)

 By recorded announcement:

 Without cut-through to operator ___

 With cut-through to operator ___

 By operator ___

10.2.2 Changed number intercept shall be: (Check One)

 By recorded announcement:

 Without cut-through to operator ___

 With cut-through to operator ___

 By operator ___

 By automatic intercept system (AIS) in distant office ___

10.2.3 Method of Reaching Operator, if required:

 Separate trunk group ___

 Regular interoffice toll trunks with idle

 trunk selecting over at least three trunks

 when three or more toll trunks are equipped ___
Bulletin 1753E-001 (Form 522)

Page III-16

 Office Name

 (By Location)________________

Part III, January 1996

10.2.4 Number of separate intercept trunk circuits ________

10.3 Line Load Control

10.3.1 Line load control facilities are:

 ___ Required ___ Not Required

 (Explain in Item 16, Part III)

10.4 Service Observing Facilities

10.4.1 Service observing facilities are:

 ___ Required ___ Not Required

 (Explain in Item 16, Part III)

10.5 Hotel-Motel Arrangements

10.5.1 Hotel-motel arrangements for operation of message

registers at the subscriber's premises are:

 ___ Required ___ Not Required

 (Explain in Item 16, Part III)

10.5.1.1 How are message registers to be activated?

 Line Reversal ____________

 Third Wire ____________

 Other ____________

 (Explain in Item 16, Part III)

10.6 Nailed-Up Connections

 ___ Required ___ Not Required

 (Explain in Item 16, Part III)
Bulletin 1753E-001 (Form 522)

Page III-17

 Office Name

 (By Location)________________

Part III, January 1996

10.7 Vertical Services: (RST Lines are Included)

 Initially Ultimate

10.7.1 Call Waiting No. of Lines ______ ________

10.7.2 Call Forwarding No. of Lines ______ ________

 ___ Local ___ Remote

 (Explain in Item 16, Part III)

10.7.3 Abbreviated Dialing No. of Lines ______ ________

 No. of Codes per Line ______ for ______ Lines

 No. of Codes per Line ______ for ______ Lines

10.7.4 Three-Way Calling No. of Lines ______ ________

 CCS Per Line ______ ________

10.7.5 Other ___

 (Explain in Item 16, Part III)

11. MAINTENANCE FACILITY REQUIREMENTS

11.1 Alarm Signals

11.1.1 Handled locally

 Explain in Detail: ________________________________

____________________________________________________________

____________________________________________________________

11.1.2 Transmitted to attended point

11.1.2.1 Via operator office trunks ___

11.1.2.2 Via printout or other display service ___

 Explain in Detail:________________________________

____________________________________________________________

____________________________________________________________
Bulletin 1753E-001 (Form 522)

Page III-18

 Office Name

 (By Location)________________

Part III, January 1996

11.1.2.3 Type of tone to operator

11.1.2.3.1 Distinctive tone ___

 (see paragraph 9.2.9 of Part I)

11.1.2.3.2 Other ___

 Explain in Detail:______________________________

____________________________________________________________

____________________________________________________________

11.1.3 Alarm checking signals for carrier and mobile radio

systems

11.1.3.1 Minor Alarm ___

11.1.3.2 Major Alarm ___

11.1.3.3 Terminals for both ___

11.2 Trouble Location and Test

11.2.1 Outside plant and stations (check desired items)

11.2.1.1 Subscriber's loop test circuit:

11.2.1.1.1 As part of the maintenance center ___

11.2.1.1.2 Separately ___

11.2.1.2 Remote test set ___

 (Explain in Item 16, Part III)

11.2.1.3 Dial speed test circuit ___

 (Explain in Item 16, Part III)

11.2.1.4 Pushbutton dialing test circuit ___

11.2.1.5 Howler ___

 (per paragraph 15.2.3.3 of Part I)

11.2.1.6 Hand test sets, number required _________

 (Explain in Item 16, Part III)
Bulletin 1753E-001 (Form 522)

Page III-19

 Office Name

 (By Location)________________

Part III, January 1996

11.3 Transmission Tests

11.3.1 Furnish reference tone Yes ___ No ___

 Frequencies and Order Time Interval for

 in Which Applied Application of Each Frequency

 ____________Hz ___________Seconds

 ____________Hz ___________Seconds

 ____________Hz ___________Seconds

 ____________Hz ___________Seconds

11.3.2 Test Lines

11.3.2.1 Test Line 100 ___

11.3.2.2 Test Line 102 ___

11.3.2.3 Test Line 104 ___

11.3.2.4 Test Line 105 ___

 (Explain in Item 16, Part III)

11.3.2.5 Test Line 107 ___

11.3.2.6 Remote Office Test Line ___

 (Explain in Item 16, Part III)

11.4 Line Testing

11.4.1 Automatic line insulation testing Yes ___ No ___

11.4.2 Owner supplied equipment Yes ___ No ___

11.4.2.1 Vendor supplied interface only Yes ___ No ___

 If supplied by owner, explain in Item 16,

 Part III, including manufacturer, model,

 location.

11.5 Remote Control

11.5.1 Remote control of the system shall be provided.

 Yes ___ No ___

 If required, explain in Item 16, Part III,

 including number, type and location.
Bulletin 1753E-001 (Form 522)

Page III-20

 Office Name

 (By Location)________________

Part III, January 1996

12. POWER EQUIPMENT REQUIREMENTS (HOST OFFICE ONLY)

12.1 Central Office Battery

12.1.1 A battery reserve of __________ busy hours shall be

provided for this office when it reaches __________ lines at the

ultimate anticipated traffic rates specified in Item 7.2, Part

III.

12.1.1.1 The owner will furnish a standby generator, permanently

installed in this office, with capacity sufficient to power air

conditioning equipment required for cooling of the central office

equipment and to maintain an adequate dc supply in the event of a

failure of the commercial ac supply.

 Yes ___ No ___

12.1.2 Type of battery: (Check One) Lead Calcium ___

 Lead Antimony ___

12.1.3 Voltmeter (portable 3-60-150 volt scale, 1% accuracy)

shall be furnished.

 Yes ___ No ___

12.1.4 Hydrometer in a hydrometer holder with glass or plastic

drop cup shall be furnished.

 Yes ___ No ___

12.1.5 Type of battery rack required: (Check One)

 Two Tier ___ Other ___ Explain: _____________

_______________________________________________________________

_______________________________________________________________

12.1.6 Special equipment power requirements (carrier, voice

frequency repeaters, etc.). Drain in amperes ____________.

12.1.6.1 Supply all necessary equipment to provide the following

48-volt battery taps:

 Fuse (or Circuit

 Number of Circuits Breaker) Size

 __________________ ________________

 __________________ ________________

 __________________ ________________

 __________________ ________________
Bulletin 1753E-001 (Form 522)

Page III-21

 Office Name

 (By Location)________________

Part III, January 1996

12.2 Charging Equipment

12.2.1 Charging equipment shall be provided capable of charging

the office battery on a full float basis when the office reaches

___________ lines at the ultimate anticipated traffic rates

specified in Item 7.2, Part III.

12.2.2 Charger input rating shall be:

 3-Phase Connection:

 Voltage ____________ 3-Wire _______

 Phase ____________ 4-Wire _______

 Frequency ____________ Delta _______

 Y _______

12.3 Ringing Equipment

12.3.1 Solid-state ringing equipment in accordance with

paragraph 19.5.1 of Part I shall be provided for generating the

frequencies specified by check marks in the following table.

Ringing generator sets serving the entire office shall each be

sized to carry the full office ringing load when the office size

reaches ____________ lines at the ultimate anticipated traffic

rates specified in Item 7.2, Part III.

12.3.2 Ringing frequencies to be supplied:

 Frequency Maximum No. of

 in Hz Telephones 

 Single Frequency 20 ____ ______________

 Decimonic 20 ____ ______________

 30 ____ ______________

 40 ____ ______________

 50 ____ ______________

 Harmonic 16-2/3 ____ ______________

 25 ____ ______________

 33-1/3 ____ ______________

 50 ____ ______________

 Synchromonic 20 ____ ______________

 30 ____ ______________

 42 ____ ______________

 54 ____ ______________
Bulletin 1753E-001 (Form 522)

Page III-22

 Office Name

 (By Location)________________

Part III, January 1996

12.3.3 Furnish frequency meter (accurate within 1.3 Hz) and

voltmeter (5% accuracy) for ringing measurements (see paragraph

19.7.2 of Part I). Check One:

 Panel Mounted ___ Portable ___ Not Required ___

12.4 Power Board

The power panel and associated wiring shall be of ample size to

meet the load requirements when this office reaches ____________

lines at the ultimate anticipated traffic rates specified in Item

7.2, Part III.

13. DISTRIBUTING FRAME REQUIREMENTS (HOST OFFICE ONLY)

13.1 Total number of outside plant cable pairs to

be terminated _________

13.1.1 Gauge of outside plant cable pairs _________

13.2 Number of outside plant cable pairs to be

protected _________

13.3 Number of additional protector pair units to

be provided on MDF _________

 Explain: _______________________________________________

_______________________________________________________________

_______________________________________________________________

13.4 Main Frame Details

 Is present MDF to be reused? Yes ___ No ___

 If "Yes," Type ____________

 Reused protectors are:

 __________ (Mfgr.) ___________ (Type)

13.4.1 Number of pairs of arrester units

 (switching equipment)____________

13.4.2 Number of pairs of gas tube arrester units

 (special equipment)___________

13.4.2.1 Gas tubes to be:

 ___light, ___medium, ___heavy, ___max. duty units
Bulletin 1753E-001 (Form 522)

Page III-23

 Office Name

 (By Location)________________

Part III, January 1996

13.4.2.2 Fail shorted/low breakdown failure mode required

 Yes ___ No ___

13.4.2.3 Breakdown voltage of gas tube arresters __________

13.4.3 Number of terminated pairs to be grounded __________

13.4.4 Factory assembled tip cable Yes ___ No ___

13.4.4.1 Tip cable length [if other than 20 feet (610 cm)]

 _________

13.4.4.2 Tip cable formed Up ___ Down ___

13.4.5 Pairs per vertical ____________

13.4.6 Height of vertical __________feet __________inches

14. BUILDING AND FLOOR PLAN INFORMATION (HOST OFFICE ONLY)

14.1 Equipment is to be installed in an

 existing building (Attach detailed plan.) ___

14.2 A new building is planned ___

14.2.1 Tentative plan (Note to Engineer: Show sketch without

dimensions.)

14.3 Detailed Arrangements

14.3.1 Partition required (to isolate space containing battery,

charger, power board, test panel, main distributing frame and

subscriber's loop test circuit (wire chief's test desk) from that

of the remaining equipment).

 Yes ___ No ___

14.3.2 Vestibule required Yes ___ No ___

14.3.3 Cable entrance Overhead ___ Underground ___

14.3.4 Additional floor space will be required for the following

equipment which is being furnished by the owner or by the

connecting company:

 ____________________________________________________

 ____________________________________________________

 ____________________________________________________
Bulletin 1753E-001 (Form 522)

Page III-24

 Office Name

 (By Location)________________

Part III, January 1996

14.3.5 The office will be arranged for

 Overhead Interbay Cabling ___

 Underfloor (Computer Room Type) Interbay Cabling ___

14.3.6 Is earthquake bracing required? Yes ___ No ___

 (If "Yes," explain zone and criteria used for zone

 in Item 16, Part III.)

14.3.7 Office ground will be __________ ohms or less

 (Refer to Item 4.6.3 of RUS TE&CM 810.)

14.3.8 The office is considered to be in the following category

for lightning damage probability based on the Figure 1 map of RUS

TE&CM 823 (see paragraph 21.2 of Part I).

 ___ Very High ___ Lower than Average

 ___ Higher than Average ___ Very Low

 ___ Average

14.3.9 The following is additional information regarding

operating environment conditions which should be considered in

determining system protection requirements (tower in vicinity,

high exposure, etc.):
Bulletin 1753E-001 (Form 522)

Page III-25

 Office Name

 (By Location)________________

Part III, January 1996

15. ALTERNATE REQUESTS
Bulletin 1753E-001 (Form 522)

Page III-26

 Office Name

 (By Location)________________

Part III, January 1996

16. EXPLANATORY NOTES: (Include a detailed description of any

equipment to be reused, or otherwise supplied by the owner, loop

extenders, subscriber carrier, VF repeaters, etc.)
Bulletin 1753E-001 (Form 522)

Page IV-1

RST Designation__________

Host Office _________

Part IV, January 1996

PART IV

DETAILED INFORMATION ON REMOTE SWITCHING TERMINALS (RST'S)

(Complete One Form For Each RST)

1. NUMBER OF SUBSCRIBER LINES: (These lines included in

 totals in Item 6, Part III).

1.1 Single-Party: ________Flat Rate ________Message Rate

1.2 Semi-Postpay Pay Station _______

1.3 Prepay Pay Station ________

1.4 PABX Lines ________ Loop Start ___ Ground Start ___

 Restricted at Office ___ Other ___

 (Describe in Item 12, Part IV)

1.5 Number of lines to be pushbutton ________

1.6 911 Emergency Lines ________

1.7 Anticipated ultimate capacity (20-Year) ________

2. TRAFFIC

2.1 Originating traffic per line - CCS/BH: ________Initial

 ________Ultimate

2.2 Terminating traffic per line - CCS/BH: ________Initial

 ________Ultimate

2.2.1 Terminating will be made equal to originating if it is not

known to be different.

3. SUBSCRIBER LOOP RESISTANCE

3.1 Number of subscriber lines having loop resistance,

 including the telephone set of:

 No. of Lines

 1501 - 1900 Ohms ____________

 1901 - 3200 Ohms ____________
Bulletin 1753E-001 (Form 522)

Page IV-2

RST Designation__________

Host Office _________

Part IV, January 1996

3.2 Number of pay station lines having loop resistance,

excluding the telephone set, greater than:

 No. of Lines

 1200 Ohms (For Prepay) ____________

 1000 Ohms (For Semi-Post

 Pay Operation) ____________

4. RANGE EXTENSION

4.1 If no standby power is available at the site, loop extenders

may be required on 1501 to 1900 ohms loops.

4.2 Loop extenders: Total Quantity __________

 By Bidder - Quantity __________

 By Owner - Quantity __________

 (Explain in Item 12, Part IV)

4.3 VF repeaters: Total Quantity __________

 By Bidder - Quantity __________

 By Owner - Quantity __________

 (Explain in Item 12, Part IV)

5. POWER SUPPLY

5.1 Power Board

5.1.1 The power board and associated wiring shall be of ample

size to meet the load requirements when this RST reaches ________

lines at the ultimate anticipated traffic rates specified in Item

2, Part IV.

5.2 Charger input rating shall be:

 Voltage ________ 3-Phase Connection:

 Phase ________

 Frequency ________ 3-Wire ___________

 4-Wire ___________

 Delta ___________

 Y ___________
Bulletin 1753E-001 (Form 522)

Page IV-3

 Office Name

 (By Location)________________

Part V, January 1996

5.2.1 Charger shall be capable of charging the RST battery on a

full float basis when the RST reaches __________ lines at

ultimate traffic rate specified in Item 2, Part IV.

5.2.2 Charger shall be redundant ___

5.3 Battery reserve shall be __________ busy hours when the RST

reaches _________ lines at the ultimate anticipated traffic

specified in Item 2, Part IV.

5.4 Standby power is available. Yes ___ No ___

5.5 Special equipment power requirements ________ amps

5.6 Ringing

5.6.1 Type of Ringing

5.6.2 Frequency No. 1. 2. 3. 4.

 Frequency HZ _____ _____ _____ _____

 Max. No. Phones/

 Frequency _____ _____ _____ _____

5.6.3 Wattage to be sized for __________ lines.

5.6.4 Frequency Meter (see Item 12.3.3, Part III)

 Panel Mounted ___ Not Required ___

6. EMERGENCY OPERATION

6.1 If path to central office is opened, the RST shall be able

to complete calls between subscribers in its own system:

 Yes ___ No ___

 Further requirements should be listed under Item 12, Part IV.

7. RST DISTRIBUTION FRAME REQUIREMENTS

7.1 Total number of outside plant cable pairs to

be terminated _________

7.1.1 Gauge of outside plant cable pairs __________
Bulletin 1753E-001 (Form 522)

Page IV-4

RST Designation__________

Host Office _________

Part IV, January 1996

7.2 Number of outside plant cable pairs

to be protected __________

7.3 Number of additional protector pair units to be

provided on MDF __________

 Explain: _________________________________________________

________________________________________________________________

________________________________________________________________

7.4 Main Frame Details

7.4.1 Present MDF to be reused Yes ___ No ___

 If "Yes", Type _____________

 Reused protectors are:

 __________(Mfr.) ___________(Type)

7.4.2 Number of pairs of arrester units

 (switching equipment) __________

7.4.3 Number of pairs of gas tube arrester units

 (special equipment) __________

7.4.3.1 Gas tubes to be:

 ___ light, ___ medium, ___ heavy, ___ maximum duty units.

7.4.3.2 Fail shorted/low breakdown failure mode required

 Yes ___ No ___

7.4.3.3 Breakdown voltage of gas tube arresters ________

7.4.4 Number of terminated pairs to be grounded ________

7.4.5 Factory assembled tip cable Yes ___ No ___

7.4.5.1 Tip cable length [if other than 20 feet(610 cm)]

 ________

7.4.5.2 Tip cable formed Up ___ Down ___

7.4.6 Pairs per vertical _________

7.4.7 Height of vertical ________feet ________inches
Bulletin 1753E-001 (Form 522)

Page IV-5

 Office Name

 (By Location)________________

Part V, January 1996

8. BUILDING AND FLOOR PLAN INFORMATION

8.1 RST to be mounted in building ___

8.1.1 Earthquake bracing required

 Yes ___ No ___ (see Item 14.3.6, Part III)

8.1.2 Supply building floor plan

8.2 RST to be mounted in cabinet out of doors ___

8.2.1 Cabinet to be mounted ______on pole ______on ground

9. SUBSCRIBER LINE TEST

9.1 Remote testing of subscriber lines is required

 Yes ___ No ___

9.2 Subscriber loop test set ___

10. SPAN LINES TO HOST CENTRAL OFFICE

10.1 To be supplied by Owner ___

10.2 To be supplied by Bidder ___

10.2.1 When the bidder is to supply the span lines, an RUS Form

397b, Trunk Carrier Systems, with the applicable parts completed

must be attached with a physical layout of the span line.

11. GROUNDING CONSIDERATIONS

11.1 The RST ground will be ________ ohms or less. (Refer to

Item 4.6.3 of RUS TE&CM 810.)

11.2 This RST is considered to be in the following category for

lightning damage probability based on the Figure 1 map of RUS

TE&CM 823.

 ___ Very High ___ Lower than Average

 ___ Higher than Average ___ Very Low

 ___ Average
Bulletin 1753E-001 (Form 522)

Page IV-6

RST Designation__________

Host Office _________

Part IV, January 1996

11.3 The following is additional information regarding operating

environment conditions which should be considered in determining

system protection requirements (tower in vicinity, high exposure,

etc.):

12. EXPLANATORY NOTES
Bulletin 1753E-001 (Form 522)

Page V-1

Part V, January 1996

PART V

SPECIFICATIONS FOR DIGITAL, STORED PROGRAM CONTROLLED CENTRAL

OFFICE EQUIPMENT DETAILED REQUIREMENTS - BIDDER SUPPLIED

INFORMATION

Telephone Company

Name ___________________________________________________________

Location

_________________________________________________________________

Central Office Name (By Location)

Town ______________ County ____________ State _____________

Attended ________ Unattended ______

1. GENERAL

1.1 The equipment and materials furnished by the bidder must

meet the requirements of Parts I, III and IV of this bulletin.

1.2 Part I of this bulletin covers the minimum general

requirements for digital, stored program controlled central

office switching equipment.

1.3 Part II of this bulletin covers requirements for

installation, inspection, and testing when such service is

included as part of the contract.

1.4 Part II and IV of this bulletin cover the technical data for

application engineering and detailed equipment requirements

insofar as they can be established by the owner. These parts are

to be filled in by the owner.

1.5 Part V of this bulletin covers detailed information on the

switching network equipment and the stored program controlled

equipment, and information as to system reliability and heavy

traffic delays as proposed by the bidder. This part is to be

filled in by the bidder and must be presented with the bid.

1.6 Part VI of this bulletin is the single-point grounding

system audit checklist.
Bulletin 1753E-001 (Form 522)

Page V-2

 Office Name

 (By Location)________________

Part V, January 1996

2. PERFORMANCE OBJECTIVES

2.1 Reliability (see paragraph 2 of Part I)

___________________________________________________________

___________________________________________________________

___________________________________________________________

___________________________________________________________

2.2 Busy Hour Load Capacity and Traffic Delay (see paragraph

5.10 of Part I. Describe basis for traffic analysis.)

___________________________________________________________

___________________________________________________________

___________________________________________________________

___________________________________________________________

3. EQUIPMENT QUANTITIES DEPENDENT ON SYSTEM DESIGN

3.1 Switch Frames and Circuits

3.1.1 Number of Lines

3.1.1.1 The number of lines to be provided shall include the

number required for the termination of subscriber lines, Item 7,

Part III, plus the number required for routine testing plus any

additional to meet the minimum switch increment of the selected

system.

3.1.1.2 The number of lines provided for this office will

be ___________.

3.1.2 Number of Ports Used for Trunks

3.1.2.1 The number of trunk ports to be provided shall be based

on the trunk quantities required (Item 8, Part III) as modified

by the minimum increment of the selected system. Provision shall

be made for at least 5 percent additional inlet and outlet ports

over those required initially. The additional ports shall be

used for connecting additional trunks that may be required in the

future.
Bulletin 1753E-001 (Form 522)

Page V-3

 Office Name

 (By Location)________________

Part V, January 1996

3.1.2.2 The number of trunk ports provided for this office

will be ___________.

3.1.3 Number of Subscriber Directory Numbers

3.1.3.1 The number of directory numbers provided shall be based

on the total directory numbers required (Item 6.1.11, Part III),

as modified by the memory increment of the proposed system.

3.1.3.2 The number of subscriber directory numbers provided for

this office will be ____________.

4. RST

4.1 Information for RST's must be supplied for each RST to be

furnished.

4.2 Number of line terminals for this RST will be ________.

4.3 Number of span line terminations to the central office

being supplied ____________.

4.4 If the emergency operation option is required, it will

provide the following service when connection to the main office

is severed:

___________________________________________________________

___________________________________________________________

___________________________________________________________

4.5 The ac power drain at the remote end will be:

 Initial ________ Ultimate________

 Voltage: Single-Phase________ Three-Phase________

4.6 Special environmental requirements for the remote end:

___________________________________________________________

___________________________________________________________

___________________________________________________________
Bulletin 1753E-001 (Form 522)

Page V-4

 Office Name

 (By Location)________________

Part V, January 1996

5. POWER

5.1 AC Power Drain Watts

 Initial ________ Ultimate ________

5.2 Heat Dissipation Watts

Provide the initial and ultimate equipment dissipation for each

equipment room.

5.2.1 Operating Temperature Range

 Minimum _________ Maximum _________

5.2.2 Operating Humidity Range

 Minimum _________ Maximum _________

6. ADDITIONAL INFORMATION TO BE FURNISHED BY BIDDER

6.1 The bidder shall accompany its bid with the following

information:

 a. Two copies of the equipment list and the calculations

from which the quantities in the equipment list are determined;

 b. Two copies of the traffic tables from which the

quantities are determined, other than the full availability

tables shown in paragraph 16.1.1 of Part I;

 c. Two copies of detailed switching diagram showing the

traffic on each route, the grade of service, the quantity of

circuits, and main distributing frames;

 d. Block diagram of stored program control and associated

maintenance equipment;

 e. A prescribed method and criteria for acceptance of the

completed central office, which is subject to review;

 f. Location of technical assistance service with 24-hour

maintenance, and conditions when owner will be charged for access

to the service;

 g. Calculations showing the method by which ringing machine

sizes were derived;
Bulletin 1753E-001 (Form 522)

Page V-5

 Office Name

 (By Location)________________

Part V, January 1996

 h. Precautions to be taken against static discharge;

 i. Details of central office grounding requirements,

recognizing local grounding conditions;

 j. Details concerning traffic measurement capabilities and

formats; and

 k. Details concerning AMA features and formats to be

provided.

6.2 As a part of the response to the bid, the bidder must also

list information concerning the types and quantities of spare

parts to be furnished. All units, excluding those units

described in paragraph 24.6.1.3 of Part I, must fall into one of

the four classes. The information must be in the following

format:

Quantity Of Units

In The CO's & RST's

Which Are Bid

Quantity of

Spare Parts Furnished

With This Bid

________________________ _________________________

Unit Unit Class Class

No. Name 1 2341234

_____ _____ _____ _____ _____ _____ _____ _____ _____ _____

7. EXPLANATORY NOTES
[Page left intentionally blank]
Bulletin 1753E-001 (Form 522)

Page VI-1

Part VI, January 1996

PART VI

ACCEPTANCE CHECKLIST - SINGLE-POINT GROUNDING SYSTEM

1. APPROVAL STATEMENT

 Telephone Company: _______________________________________

 RUS Borrower Designation: ________________________________

 RUS Contract Number: ________________ N/A ____

 Name:

 Central Office: ___________________________________________

 Remote: ___________________________________________________

 Date of Inspection: _______________

 Names of Inspectors:

 Owner Representative ____________________________________

 Central Office Supplier _________________________________

 Consulting Engineer _____________________________________

 Mutually Approved Exceptions:

 ___________________________________________________________

 ___________________________________________________________

 ___________________________________________________________

 ___________________________________________________________

 Grounding System Approval:

 Name Signature Title Date 

______________________ ________________ _________ ________

(Owner Representative)

______________________ ________________ _________ ________

(Supplier Representative)
Bulletin 1753E-001 (Form 522)

Page VI-2

 Office Name

 (By Location)________________

Part VI, January 1996

2. GENERAL SURVEY

2.1 This office is considered to be in the following category

for probability of lightning damage based on the Figure 1 map in

RUS TE&CM 823 (also refer to paragraph 21.2 of Part I)

 ___ Very High ___ Lower than Average

 ___ Higher than Average ___ Very low

 ___ Average

2.2 Central office ground field (COGF) to be inspected for

proper bonding of conductors to ground rods, etc. COGF to earth

grounding reading is ______ ohms. (Refer to RUS TE&CM 802,

Appendices C and D, Measurement Techniques.) Is this resistance

reading acceptable? (Refer to RUS TE&CM 810, Items 1.6, 4.6.2

and 4.6.3 for protection considerations.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

2.3 Ground connection to be inspected from the master ground bar

(MGB) to the central office ground field (COGF) to ensure it is

properly sized and installed by most direct route with no sharp

bends. (Refer to RUS TE&CM 810, Item 4.3.2 and section 8.1.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

2.4 Building structure grounds (steel rebar in footings,

ironwork, etc.) are to be properly bonded and connected to the

MGB. (Refer to RUS TE&CM 810, Item 4.3.4.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________
Bulletin 1753E-001 (Form 522)

Page VI-3

 Office Name

 (By Location)________________

Part VI, January 1996

2.5 Metallic central office door(s) are to be painted with

metallic paint with doorknobs left bare. Door(s) and frames are

to be grounded to the building structural ground or the MGB.

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

2.6 Metallic fences within 6 feet (183 cm) of the exchange

building, storage facilities ground field, etc. are to be

properly bonded to the COGF outside of the central office

building. Handhole enclosure is to be used for the COGF

connection to permit inspection and disconnect for earth

resistance testing. (Refer to RUS TE&CM 810, Appendix C, Item

4.6.1.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

2.7 Lightning rod systems are to be grounded by a separate

dedicated ground field. A bond should be provided between the

COGF and the lightning rod ground field. Handhole enclosure is

to be used for the COGF connection to permit inspection and

disconnect for earth resistance testing. (Refer to RUS TE&CM

810, Item 4.3.2.1.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

2.8 Radio/microwave tower ground grid is to be properly bonded

to the COGF by a direct outside connection. Handhole enclosure

is to be used for the COGF connection to permit inspection and

disconnect for earth resistance testing. (Refer to RUS TE&CM

810, Item 4.3.2 and section 10.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________
Bulletin 1753E-001 (Form 522)

Page VI-4

 Office Name

 (By Location)________________

Part VI, January 1996

2.9 If a qualified metallic water system is present, inspect the

MGB connecting conductor to ensure that it is properly sized and

installed by the most direct route with no sharp bends and that

it is clamped solidly on the water pipes. (Refer to RUS TE&CM

810, Item 4.3.3 for details on metallic water system grounding.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

2.10 All power and grounding conductors are to be continuous,

end to end, with no splices, size discontinuity or intermediate

terminations. If an exception is necessary, unusual care must be

taken to assure proper bonding between the two sections. (Refer

to RUS TE&CM 810, Appendix C, section 5.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

2.11 All ground conductors should be void of sharp bends along

their entire lengths. (Refer to RUS TE&CM 810, Item 8.2.2.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

2.12 Ground conductors should only be placed in nonmetallic

conduit. Those routed through metallic conduit require that both

ends of the conduit be bonded to the ground conductor. (Refer to

RUS TE&CM 810, Item 8.2.4.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________
Bulletin 1753E-001 (Form 522)

Page VI-5

 Office Name

 (By Location)________________

Part VI, January 1996

2.13 Ground conductors should not be encircled by metallic

clamp. Metallic straps are to be removed and replaced with

nonmetallic clamps. (Refer to RUS TE&CM 810, Item 8.2.4.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

2.14 If metallic conduit is used, it is to be insulated from all

ironwork.

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

2.15 Inspect to determine if the required central office

supplier electrostatic discharge plates, wrist wraps, antistatic

floor mats, etc. are available and properly installed. (Refer to

RUS TE&CM 810, Item 12.3.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

2.16 Ground conductors, except green wires, should not be routed

close and parallel to other conductors so as to minimize

induction on surges into equipment wiring. It is also better not

to route these ground conductors through cable racks or troughs,

or within the confines of any iron work. (Refer to RUS TE&CM

810, Item 8.2.3.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________
Bulletin 1753E-001 (Form 522)

Page VI-6

 Office Name

 (By Location)________________

Part VI, January 1996

3. MASTER GROUND BAR (MGB)

3.1 The designated P, A, N, and I segments of the master ground

bar (MGB) should be clearly identified. (Refer to RUS TE&CM 810,

Figure 1 for MGB segmentation arrangement.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

3.2 Check for appearance and proper location of following on

MGB:

 (a) R - Interior radio equipment(1)

 (b) C - Cable entrance ground bar(1)

 (c) M - MDF ground bar (1)

 (d) G - Standby power equipment frame ground (1)

 (e) N - Commercial power MGN(2)

 (f) B - Building structure ground(2)

 (g) L - Central office ground field(2)

 (h) W - Water pipe system(2)

 (i) N1 - Battery Return(3)

 (j) N2 - Outside IGZ: __________(3)

 (k) N3 - Outside IGZ: __________(3)

 (l) I1 - Ground window bar(4)

 (m) I2 - Ground window bar(4)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

_________________________

(1) Surge Producer - (P)

(2) Surge Absorber -(A)

(3) Grounds to non-IGZ Equipment - (N)

(4) Grounds to IGZ Equipment (GWB's) - (I)

____________________________________________________________
Bulletin 1753E-001 (Form 522)

Page VI-7

 Office Name

 (By Location)________________

Part VI, January 1996

3.3 All connections to MGB are to be two-hole bolted down copper

crimped or compression type terminal lugs. (NOTE: No solder

connections are permitted.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

3.4 MGB is to be properly insulated from the mounting surface.

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

3.5 All connections are to be tight.

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

3.6 The MGB is to have an anticorrosion coating of the type

which enhances conductivity.

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

3.7 Bar is to be clearly stenciled or legibly labeled "MGB."

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________
Bulletin 1753E-001 (Form 522)

Page VI-8

 Office Name

 (By Location)________________

Part VI, January 1996

3.8 All ground leads are to be properly sized and labeled as to

point of origin. (Refer to RUS TE&CM 810, Item 8.3.1 and section

8.1.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

4. GROUND WINDOW BAR (GWB)

4.1 All equipment grounds that originate inside of an Isolated

Ground Zone (IGZ) are to be terminated on the GWB which is

preferably located physically inside the IGZ and insulated from

its support. (Refer to RUS TE&CM 810, Item 5.1.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

4.2 Each GWB is to be connected to the MGB by the most direct

route with a conductor of 2/0-gauge or coarser, or resistance of

less than 0.005 ohms. Parallel conductors for redundancy if

required by the supplier. (Refer to RUS TE&CM 810, Item 8.1.2.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

4.3 The metal framework grounds of only that switching equipment

and associated electrical equipment located inside of the IGZ

should be connected to the GWB as required by the central office

equipment supplier. (Refer to RUS TE&CM 810, Item 5.5.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________
Bulletin 1753E-001 (Form 522)

Page VI-9

 Office Name

 (By Location)________________

Part VI, January 1996

4.4 GWB is to be clearly stenciled or labeled "GWB."

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

4.5 All connections are to be tight.

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

5. ISOLATED GROUND ZONE (IGZ)

5.1 IGZ areas are to be clearly marked on the floor or in some

other easily recognizable manner. (Refer to RUS TE&CM 810, Item

6.1.1)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

5.2 Confirm that all framework, cabinets, etc., within the IGZ

are ground connected only to the GWB. (Refer to RUS TE&CM 810,

Item 5.5.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

5.3 All cable racks, ground mats, switching and transmission

equipment within the IGZ are to have ground leads only to the

GWB. (Refer to RUS TE&CM 810, Item 5.5.2.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________
Bulletin 1753E-001 (Form 522)

Page VI-10

 Office Name

 (By Location)________________

Part VI, January 1996

5.4 Review ac power feed arrangement within the IGZ for

acceptable receptacle type and confirm that all green wires are

properly connected. (Refer to RUS TE&CM 810, Item 5.5.4.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

5.5 All ironwork, metallic conduit, and other equipment

associated with the switch are to be properly insulated at the

IGZ boundary as stipulated by the supplier. (Refer to RUS TE&CM

810, Item 6.2.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

5.6 With the GWB disconnected from the MGB, the resistance

reading of _______ ohms between the GWB and the MGB indicates

adequate isolation. (CAUTION: Test is to be conducted only with

the approval and under the direction of the central office

supplier.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

6. ENTRANCE AND TIP CABLES

6.1 When neither a cable vault nor a splicing trough exists, the

outside plant cable should be brought into the central office and

spliced to tip cables with a PVC outer jacket (ALVYNR) or

equivalent as close as practical to the cable entrance. (Refer

to RUS TE&CM 810, Item 7.3.4.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________
Bulletin 1753E-001 (Form 522)

Page VI-11

 Office Name

 (By Location)________________

Part VI, January 1996

6.2 All outside entrance cables and all tip cable shields are to

be separated by at least a 3-inch (7.6 cm) gap between shield

ends.

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

6.3 All entrance cable shields are to be bonded separately to #6

AWG or larger insulated wire or bonding ribbon and connected to

the Cable Entrance Ground Bar (CEGB) by most direct route with

minimum bends.

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

6.4 Outside plant cable shields are to be connected only to the

CEGB, and the tip cable shields are to be connected only to the

Main Distributing Frame Bar (MDFB).

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

7. CABLE ENTRANCE GROUND BAR (CEGB)

7.1 The CEGB is to be properly insulated from the mounting

surface. (Refer to TE&CM 810, Item 4.2.1.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________
Bulletin 1753E-001 (Form 522)

Page VI-12

 Office Name

 (By Location)________________

Part VI, January 1996

7.2 The CEGB is to be located as close as possible to the

physical ends of the entrance cable shields.

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

7.3 All connections are to use two-hole bolted down copper

crimped or compression type terminal lugs. (NOTE: No solder

connections are permitted.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

7.4 All connections are to be tight.

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

7.5 Bar is to be clearly stenciled or legibly labeled "CEGB."

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

7.6 All ground leads are to be properly sized and labeled.

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________
Bulletin 1753E-001 (Form 522)

Page VI-13

 Office Name

 (By Location)________________

Part VI, January 1996

7.7 The CEGB is to have an anticorrosion coating of the type

which enhances conductivity.

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

7.8 The CEGB is to be connected to the MGB by a properly sized

conductor and by the most direct route. (Refer to RUS TE&CM 810,

section 8.1.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

8. MAIN DISTRIBUTING FRAME (MDF)

8.1 RUS strongly recommends that MDF protectors be furnished

without heat coils. (Refer to RUS TE&CM 810, section 7.6.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

8.2 Incoming cable pairs terminated on MDF protector assemblies

should be protected with protector modules. These modules should

contain white coded carbon blocks or orange coded gas tube

arrestors that are included in the RUS List of Materials. (Refer

to RUS TE&CM 810, Item 7.4)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________
Bulletin 1753E-001 (Form 522)

Page VI-14

 Office Name

 (By Location)________________

Part VI, January 1996

8.3 All incoming subscriber cable pairs are to be properly

terminated at either a protector equipped terminal or connected

to ground.

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

8.4 MDF protector assemblies may be mounted directly on the

vertical frame ironwork. Protector assemblies on each vertical

are interconnected with each other and the Main Distributing

Frame Bar (MDFB) with a #6 copper grounding conductor.

Alternative means of connecting to the MDFB are also acceptable

which do not rely on the frame ironwork for conducting surge

currents to ground. (Refer to RUS TE&CM 810, section 7.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

8.5 Protective "ground connections" should be provided between

the MDFB and the frame ironwork for personnel protection

regardless of the type of protector assembly used. Protective

ground leads should be 14-gauge, less than 12 inches (30.5 cm) in

length with paint thoroughly removed at point of connection to

the ironwork. (Refer to RUS TE&CM 810, Item 7.1.3.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

8.6 The MDFB should be insulated from the frame ironwork in all

cases where it is used as a Master Ground Bar (MGB). (Refer to

RUS TE&CM 810, Item 7.1.2.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________
Bulletin 1753E-001 (Form 522)

Page VI-15

 Office Name

 (By Location)________________

Part VI, January 1996

8.7 Where the MDFB is used as the MGB in very small offices the

protective "ground connections" should be connected on the N

section of the bar. The MDF line protector assembly grounds

should be connected to the P section of the bar. (Refer to RUS

TE&CM 810, Item 7.1.4.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

8.8 The MDFB is to be connected to the MGB by the most direct

path with minimum bends and proper conductor size. (Refer to RUS

TE&CM 810, Item 8.1.4.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

8.9 The MDFB should be free of all other ground leads when not

used as an MGB.

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

8.10 Alternative arrangements which insulate the line protector

assemblies and MDFB from the frame ironwork may require a direct

ground connection of the frame ironwork to the MGB for personnel

protection. Conductor is properly sized and tightened with paint

removal on main frame ironwork at point of connection.

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________
Bulletin 1753E-001 (Form 522)

Page VI-16

 Office Name

 (By Location)________________

Part VI, January 1996

9. POWER SERVICE PROTECTION AND GROUNDING

9.1 The ground conductor between the ac power system

multigrounded neutral (MGN) at the main ac disconnect panel and

the master ground bar (MGB) is to be properly sized and

connected. (Refer to RUS TE&CM 810, Items 2.19, 4.3.1 and

8.1.3.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

9.2 If there is a non-MGN ac power system, there is to be a

properly sized and connected insulated conductor bond between the

power service ground electrode and the MGB. (Refer to RUS TE&CM

810, Item 4.3.1.1.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

9.3 AC conductors including ground conductors serving 120 volt

ac electric convenience receptacles and all direct wire

peripheral equipment, located in the IGZ, should be sized in

accordance with normal "green wire" criteria. (Refer to RUS

TE&CM 810, Items 5.5.4, 5.5.5, and 5.5.6.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

9.4 Minimum protection for ac power serving the central office

buildings should consist of an RUS accepted secondary arrestor at

the service entrance. (Refer to RUS TE&CM 810, section 9.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________
Bulletin 1753E-001 (Form 522)

Page VI-17

 Office Name

 (By Location)________________

Part VI, January 1996

9.5 A properly sized conductor for ground bonding between the

standby power plant framework (not separately derived) and the

MGB is to be provided to equalize framework voltages for

personnel safety reasons. (Refer to RUS TE&CM 810, Item 4.2.4.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

10. MISCELLANEOUS

10.1 All non-IGZ equipment frames, relay racks, cable racks and

other ironwork are to be properly connected to the MGB. (Refer

to TE&CM 810, Item 4.4.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

10.2 Shields on high frequency intra-office cables are to be

properly isolated and connected only to an isolation ground bar

in the relay rack. All shielded cables entering the IGZ should

only be referenced at the IGZ termination point as given by the

manufacturer. (Refer to RUS TE&CM 810, Item 7.2.1.2.)

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

10.3 Isolation ground bars in the relay racks are to be properly

connected to the MGB with appropriate sized conductor with no

sharp bends.

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________
Bulletin 1753E-001 (Form 522)

Page VI-18

 Office Name

 (By Location)________________

Part VI, January 1996

10.4 All radio equipment cabinet(s) are to be at least 10 feet

(305 cm) from the IGZ.

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________

10.5 The metal spare parts cabinet is to be grounded with a #6

AWG or larger insulated wire to non-IGZ cable rack, etc. or

directly to the MGB.

 Acceptable: ___ Yes ___ No

 Comments:___________________________________________

____________________________________________________________

____________________________________________________________