Paradyne COMSPHERE 3550 Series User manual

COMSPHERE
3550 SERIES
DATA SERVICE UNITS
MODELS 3550 AND 3551
USER’S GUIDE
Document No. 3550-A2-GB20-40
July 1999

COMSPHERE 3550 Series Data Service Units
AJuly 1999 3550-A2-GB20-40
COMSPHERE 3550 Series
Data Service Units
Models 3550 and 3551
User’s Guide
3550-A2-GB20-40
5th Edition (July 1999)
Changes and enhancements to the product and to the information herein will be documented and issued as a new release.
United States
FCC Registration number: AW292J-61661-DD-N
PSTN Ringer Equivalence number (REN): DBM option 0.7B
Canada
V.32 Dial Backup Module
Certification number: 230 3684 A
DOC Load number: 7
Warranty, Sales, Service, and Training Information
Contact your local sales representative, service representative, or distributor directly for any help needed. For additional information
concerning warranty, sales, service, repair, installation, documentation, training, distributor locations, or Paradyne worldwide office
locations, use one of the following methods:
•Internet: Visit the Paradyne World Wide Web site at www.paradyne.com. (Be sure to register your warranty there. Select
Technical Support →Warranty Registration.)
•Telephone: Call our automated system to receive current information by fax or to speak with a company representative.
— Within the U.S.A., call 1-800-870-2221
— Outside the U.S.A., call 1-727-530-2340
Document Feedback
We welcome your comments and suggestions about this document. Please mail them to Technical Publications, Paradyne Corporation,
8545 126th Ave. N., Largo, FL 33773, or send e-mail to [email protected]. Include the number and title of this document in
your correspondence. Please include your name and phone number if you are willing to provide additional clarification.
Trademarks
All products and services mentioned herein are the trademarks, service marks, registered trademarks or registered service marks of their
respective owners.
COPYRIGHT 1999 Paradyne Corporation. All rights reserved.
Thispublicationis protected by federalcopyright law. Nopart of this publicationmay be copied ordistributed, transmitted, transcribed, stored inaretrievalsystem,
ortranslatedintoanyhumanorcomputerlanguageinanyformorbyanymeans,electronic,mechanical,magnetic,manualorotherwise,ordisclosedtothirdparties
without the express written permission of Paradyne Corporation, 8545 126th Avenue North, P.O. Box 2826, Largo, Florida 33779-2826.
ParadyneCorporationmakesnorepresentationorwarrantieswithrespecttothecontentshereofandspecificallydisclaimsanyimpliedwarrantiesofmerchantability
orfitness for a particular purpose. Further,ParadyneCorporationreservestherighttorevisethispublicationandto make changes from time to time in the contents
hereof without obligation of Paradyne Corporation to notify any person of such revision or changes.
Printed on recycled paper

Safety Instructions
B3550-A2-GB20-40 July 1999
!Important Safety Instructions
1. Read and follow all warning notices and instructions marked on the product or
included in the manual.
2. This product is intended to be used with a 3-wire grounding type plug – a plug which
has a grounding pin. This is a safety feature. Equipment grounding is vital to ensure
safe operation. Do not defeat the purpose of the grounding type plug by modifying
the plug or using an adaptor.
Prior to installation, use an outlet tester or a voltmeter to check the ac receptacle for
the presence of earth ground. If the receptacle is not properly grounded, the
installation must not continue until a qualified electrician has corrected the problem.
If a 3-wire grounding type power source is not available, consult a qualified
electrician to determine another method of grounding the equipment.
3. Slots and openings in the cabinet are provided for ventilation. To ensure reliable
operation of the product and to protect it from overheating, these slots and openings
must not be blocked or covered.
4. Do not allow anything to rest on the power cord and do not locate the product where
persons will walk on the power cord.
5. Do not attempt to service this product yourself, as opening or removing covers may
expose you to dangerous high voltage points or other risks. Refer all servicing to
qualified service personnel.
6. General purpose cables are provided with this product. Special cables, which may be
required by the regulatory inspection authority for the installation site, are the
responsibility of the customer.
7. When installed in the final configuration, the product must comply with the applicable
Safety Standards and regulatory requirements of the country in which it is installed. If
necessary, consult with the appropriate regulatory agencies and inspection
authorities to ensure compliance.
8. A rare phenomenon can create a voltage potential between the earth grounds of two
or more buildings. If products installed in separate buildings are interconnected, the
voltage potential may cause a hazardous condition. Consult a qualified electrical
consultant to determine whether or not this phenomenon exists and, if necessary,
implement corrective action prior to interconnecting the products.
In addition, if the equipment is to be used with telecommunications circuits, take the
following precautions:
– Never install telephone wiring during a lightning storm.
– Never install telephone jacks in wet locations unless the jack is specifically designed
for wet locations.
– Never touch uninsulated telephone wires or terminals unless the telephone line has
been disconnected at the network interface.
– Use caution when installing or modifying telephone lines.
– Avoid using a telephone (other than a cordless type) during an electrical storm.
There may be a remote risk of electric shock from lightning.
– Do not use the telephone to report a gas leak in the vicinity of the leak.

COMSPHERE 3550 Series Data Service Units
CJuly 1999 3550-A2-GB20-40
Notices
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           
             
            
              
              
  
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             
  


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
 !  ! !    ! !  
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 ! !!        

Safety Instructions
D3550-A2-GB20-40 July 1999
Government Requirements
The Federal Communications Commission (FCC) requires that instructions pertaining to
connection to the telephone network be included in the installation and operation manual. Specific
instructions are listed in this section.
Notice to Users of the Digital Data Service
This equipment complies with Part 68 of the FCC rules. On the bottom of the equipment is a label
or silk-screened text that contains, among other information, the FCC registration number and
Ringer Equivalence Number (REN) for this equipment. If requested, please provide this
information to your telephone company.
The REN is useful to determine the quantity of devices you may connect to your telephone line
and still have all of those devices ring when your number is called. In most, but not all areas, the
sum of the RENs of all devices should not exceed 5. To be certain of the number of devices you
may connect to your line, as determined by the REN, you should call your local telephone
company to ascertain the maximum REN for your calling area.
If your DSU causes harm to the telephone network, the telephone company may discontinue your
service temporarily. If possible, they will notify you in advance. But if advance notice is not
practical, you will be notified as soon as possible. You will be advised of your right to file a
complaint with the FCC.
If your DSU causes harm to the telephone network, the telephone company may discontinue your
service temporarily. If possible, they will notify you in advance. But if advance notice is not
practical, you will be notified as soon as possible. You will be advised of your right to file a
complaint with the FCC.
Your telephone company may make changes in its facilities, equipment, operations, or procedures
that could affect the proper operation of your equipment. If so, you will be given advance notice so
as to give you an opportunity to maintain uninterrupted service.
The DBM cannot be used on public coin-operated telephone service provided by the telephone
company. Connection to party-line service is subject to state tariffs. (Contact the state public utility
commission, public service commission, or corporation commission for information.)
No repairs may be performed by the user. Should you experience difficulty with this equipment,
refer to the Equipment Warranty and Support section of Chapter 1.
For Digital Data Service (DDS) installations, inform the local telephone company of the
appropriate network channel interface code for the service you desire.
DDS
Interface
Code Data Rate
(bps)
04DU5-24 2400
04DU5-48 4800
04DU5-96 9600
04DU5-19 19,200
04DU5-56 56,000

COMSPHERE 3550 Series Data Service Units
EJuly 1999 3550-A2-GB20-40
The DDS Service Order Number is 6.0Y. The jack configurations required are RJ48S for the
Model 3550 DSU and RJ48T for the Model 3551. With an RJ48T configuration, you must specify
the number of data lines you require. Refer to the Technical Specifications section of Chapter 1 for
V.32 DBM jack information.
After the telephone company has installed the requested jack, you can connect the DSU with the
appropriate cable (provided). An FCC-compliant telephone cord and modular plug is provided
with this equipment. This equipment is designed to be connected to the telephone network or
premises wiring using a compatible modular jack that is Part 68 compliant.

i3550-A2-GB20-40 July 1999
Table of Contents
Preface
About This Guide vii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How to Use This Guide vii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Related Documents viii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reference Documents viii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1. About Your DSU
Overview 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Standard Features 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Optional Features 1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Upgrades Available 1-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Technical Specifications 1-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Equipment Warranty and Support 1-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2. Installing the Model 3550 DSU
Overview 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Before You Begin 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How to Change Hardware Straps 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Where to Place the DSU 2-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installing the DSU 2-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connecting to the Network 2-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Addressing the Unit 2-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connecting the DSU to a DTE 2-10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Verifying Operation and Testing Connections 2-11. . . . . . . . . . . . . . . . . . . .
3. Installing the Model 3551 DSU
Overview 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Before You Begin 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How to Change Hardware Straps 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installing the DSU 3-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connecting to the Network 3-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connecting the DSU to a DTE 3-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Addressing the Unit 3-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Verifying Operation and Testing Connections 3-10. . . . . . . . . . . . . . . . . . . .

COMSPHERE 3550 Series Data Service Units
ii July 1999 3550-A2-GB20-40
4. Operating the DSU
Overview 4-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DCP and SDCP Operation 4-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Menu Structure 4-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Status Branch 4-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Backup Branch 4-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Test Branch 4-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuration Branch 4-12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Control Branch 4-19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Messages Branch 4-20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5. Configuring the Unit
Overview 5-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using the DCP to Set Configuration Options 5-2. . . . . . . . . . . . . . . . . . . .
Configuration Option Tables 5-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appendix
A. DSU Menu A-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B. Configuration Worksheets B-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C. Status Indicators and Control Panel Messages C-1. . . . . . . . . . . . . . .
D. Pin Assignments D-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
E. Application Configurations E -1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
F. Equipment List F -1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Glossary
Index

Table of Contents
iii3550-A2-GB20-40 July 1999
List of Figures
Figure Page
2-1 Model 3550 Hardware Switch Location (shown without a TDM/Flex) 2-3. . . . . . . . . .
2-2 Model 3550 Electrical Connection 2-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-3 Model 3550 DSU NMS Connection 2-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-4 Model 3550 DSU Dial (PSTN) Network Connection 2-6. . . . . . . . . . . . . . . . . . . . . . . .
2-5 Model 3550 DSU DDS (LADS) Network Connection 2-7. . . . . . . . . . . . . . . . . . . . . . .
2-6 Addressing Example 2-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-7 Installing Cables 2-10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-1 Model 3551 DSU Switch and Jumper Locations 3-3. . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-2 COMSPHERE 3000 Series Carrier, Rear View 3-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-3 Model 3551 DSU Installation and Circuit Pack Lock 3-6. . . . . . . . . . . . . . . . . . . . . . . .
3-4 Model DSU V.35 Adapter Plug Installation 3-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-5 Addressing Example 3-10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-1 Model 3550 Diagnostic Control Panel 4-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-2 SDCP and Model 3551 DSU Faceplate 4-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-3 Loopbacks 4-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D-1 Digital Network Connector D-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D-2 3600 Hubbing Device (3600-F3-300) D-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D-3 Model 3551 DSU 25-Pin EIA-232/25-Pin V.35
Rear Connector Plate (3000-F1-021) D-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D-4 V.35 Adapter Plug (3000-F1-511) D-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D-5 EIA-232-D Crossover Cable (4951-035F)D-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D-6 V.35 Crossover Cable (3211-178F) D-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
E-1 Point-to-Point Application Configurations with Internal and
External V.32 Backup E-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
E-2 Multipoint Application Configurations E-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

COMSPHERE 3550 Series Data Service Units
iv July 1999 3550-A2-GB20-40
List of Tables
Table Page
1-1 General Technical Specifications 1-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-2 DSU Technical Specifications 1-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-3 V.32 DBM Technical Specifications 1-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-4 2-Port TDM/Flex Technical Specifications 1-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-1 Model 3550 DSU Switch Settings 2-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-2 LADS Connection Distances 2-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-1 Model 3551 DSU Switch Settings 3-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-2 Model 3551 DSU Jumper Straps 3-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-1 Identity Descriptions 4-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-2 Backup Branch Menu Selections 4-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-3 Digital Test Results 4-11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-4 End-to-End Test Results 4-11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-5 Bit Error Rate Test Results 4-12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-6 Directory Entry and Password Characters 4-18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-7 Lead States 4-20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-1 DSU Configuration Options 5-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-2 Diagnostic (DSU) Configuration Options 5-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-3 Diagnostic (DBM) Configuration Options 5-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-4 Diagnostic (External DBU) Configuration Options 5-10. . . . . . . . . . . . . . . . . . . . . . . . .
5-5 Diagnostic (General) Configuration Options 5-10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-6 DBM Configuration Options 5-12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-7 External DBU Configuration Options 5-16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-8 General Configuration Options 5-17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-9 Backup Configuration Options 5-21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-10 MUX (Setup) Configuration Options 5-23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-11 MUX (Port) Configuration Options 5-23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-12 Port Speed (DSU) Configuration Options 5-27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-13 Port Speed (DBM) Configuration Options 5-28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-14 Port Speed (External DBU) Configuration Options 5-29. . . . . . . . . . . . . . . . . . . . . . . . .

Table of Contents
v3550-A2-GB20-40 July 1999
Table Page
C-1 DSU Status Indicators C-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C-2 SDCP Status Indicators C-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C-3 Device Health and Status Messages C-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C-4 Expanded Health and Status Messages C-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C-5 Subnetwork Health and Status Messages C-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C-6 Command Progress Messages C-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C-7 Dial Backup Progress Messages C-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C-8 Command Error Messages C-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C-9 Dial Backup Error Messages C-10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C-10 TDM/Flex Error Messages C-11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D-1 Model 3550 – Digital (DDS) Network Connector Pin Assignments D-2. . . . . . . . . . . . .
D-2 Model 3550 – Dial (Analog) Network Connector Pin Assignments D-2. . . . . . . . . . . . .
D-3 3600 Hubbing Device Pin Assignments D-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D-4 3600 Hubbing Device CC IN/DC OUT Jack Pin Assignments D-3. . . . . . . . . . . . . . . . .
D-5 EIA-232/V.24 Connector Pin Assignments D-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D-6 V.35 Connector Pin Assignments D-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

COMSPHERE 3550 Series Data Service Units
vi July 1999 3550-A2-GB20-40

vii3550-A2-GB20-40 July 1999
Preface
About This Guide
This user’s guide provides the information needed to
install and operate your COMSPHERE Model 3550 or
3551 Data Service Unit (DSU), which may or may not be
equipped with a dial backup module (DBM) or time
division multiplexer (TDM). If your DSU is not equipped
with these options, skip the information that pertains to
them.
Be sure to read the safety and regulatory information at
the beginning of this guide.
It is assumed that you are familiar with the functional
operation of digital data communications equipment.
How to Use This Guide
This guide provides basic information about your DSU,
how to install it and verify that it is installed and operating
correctly, how to operate the unit and its options, and how
to configure it.
Two installation chapters are provided, one for the
Model 3550 DSU and one for the Model 3551 DSU.
Select the chapter that applies to your DSU.
Refer to the following chapters or appendices, as
needed.
Chapter 1 Provides a general overview of the
DSU and its options, information
about equipment upgrades and
conversions, and the unit’s technical
specifications. It also includes
equipment warranty information and
equipment return instructions.
Chapter 2 Provides step-by-step instructions for
installing your standalone
Model 3550 DSU.
Chapter 3 Provides step-by-step instructions for
installing your carrier-mounted
Model 3551 DSU.
Chapter 4 Describes how to operate your DSU
and its DBM and TDM/Flex options.
Chapter 5 Presents the basics of setting and
changing configuration options, and
provides Configuration Option Set
Tables, which describe each
configuration option in an option set,
along with its possible settings.
Appendix A Provides a diagram for navigating
the DSU’s menu structure.
Appendix B Summarizes the configuration option
sets for you.
Appendix C Lists the DSU’s status indicators, as
well as their messages, identifying
when they appear.
Appendix D Shows point-to-point and multipoint
application configurations and
network hookups.
Appendix E Provides cable and connector pin
assignments.
Appendix F Equipment List
Glossary
Index

COMSPHERE 3550 Series Data Service Units
viii July 1999 3550-A2-GB20-40
Related Documents
Other product documentation includes the following:
3000-A2-GA31 COMSPHERE 3000 Series
Carrier, Installation Manual
3000-A2-GB41 COMSPHERE –48 Vdc
Central Office Power Unit,
Installation Guide
6700-A2-GB41 COMSPHERE 6700 Series
Network Management System,
User’s Guide, Security
Manager Feature Supplement
6700-A2-GY31 COMSPHERE 6700 Series
Network Management System,
User’s Guide
Call your sales representative to order additional
product documentation.
Paradyne documents are also available on the World
Wide Web at www.paradyne.com. Select Library →
Technical Manuals.
Reference Documents
•AT&T Technical Reference 41458
•AT&T Technical Reference 61330
•AT&T Technical Reference 62310 – 1987
•Bell Canada DCTE Specifications
•Bell Communications Research Technical
Reference Publication 41028
•CCITT V.35 (ISO 2593)
•EIA-232-D/V.24 (ISO 2110)
•Integrated Network Corporation Compatibility
Bulletin CB-INC-101
•Pacific Bell PUB L-780035-PB/NB
•Pacific Bell PUB L-780036-PB/NB

1-13550-A2-GB20-40 July 1999
About Your DSU
Overview 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Standard Features 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Optional Features 1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
V.32 DBM 1-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-Port TDM/Flex 1-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Upgrades Available 1-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Technical Specifications 1-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Equipment Warranty and Support 1-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Overview
The COMSPHERE Model 3550 or 3551 Data Service
Unit (DSU) supports communication between computers
and other data processing devices by providing
connections to digital data service (DDS) transmission
facilities. Both point-to-point and multipoint
configurations are supported.
The following sections describe the standard features
of the DSU, as well as the features of the options that may
have been ordered with your unit. The technical
specifications of the DSU and its orderable options are
near the end of the chapter.
Standard Features
The Model 3550 or 3551 DSU offers the following
features:
•Multispeed operation. The DSU operates at data
rates of 2.4, 4.8, 9.6, 19.2, 38.4, and 56kbps
full-duplex over the digital data service (DDS)
network.
Two DTE connectors (interfaces) are provided for
Port 1: EIA-232-D and V.35. Use the EIA-232-D
connector for data rates up to and including
19.2 kbps; use the V.35 connector for higher rates.
•Rate Adaption. With this feature, the DSU can
adapt its data rate to a low-speed application while
operating over the high-speed DDS circuit.
•LADS operation. The DSU can operate as a local
area data set (LADS) (sometimes called a
limited-distance modem, or LDM) at 2.4, 4.8, 9.6,
19.2, 38.4, 56, or 64kbps.
•Single-Port Async/Sync. The single-port
asynchronous-to-synchronous feature makes it
possible to send asynchronous data over the
synchronous network.
•Nondisruptive Diagnostics. When set up to use
nondisruptive diagnostics, the DSU sends
diagnostic data without interrupting or disrupting
customer data.
•NMS control. The DSU can be controlled by
COMSPHERE 6700 Series NMS. The 6700 Series
NMS operates using Advanced Diagnostic protocol
(ADp).
The Model 3550 DSU requires a hubbing device
for connection to the NMS; the Model 3551 DSU is
connected to the NMS through the shared
diagnostic unit (SDU) in the COMSPHERE
3000 Series Carrier.
1

COMSPHERE 3550 Series Data Service Units
1-2 July 1999 3550-A2-GB20-40
•Diagnostic Control Panel control. The
Model 3550 DSU is controlled from its diagnostic
control panel (DCP). The diagnostic control panel
for the Model 3551 DSU, called a shared diagnostic
control panel (SDCP), is installed in the
3000 Series Carrier. Both control panels display
information about the DSU on a 2-line,
16-character liquid crystal display (LCD) and
through light-emitting diode (LED) status
indicators.
NOTE
Except where a distinction is
made, the term DCP refers to
both types of diagnostic control
panels, the DCP or the SDCP.
•Full tributary diagnostics. The DSU supports a
full complement of diagnostic tests and commands.
Diagnostics can be addressed to and sent to
tributaries from a 6700 Series NMS workstation or
from the DCP of a control DSU.
•External dial backup. The DSU can use an
external dial backup unit (DBU – e.g., a
3800 Series dial/lease modem) to provide backup.
This feature may be used in a point-to-point DSU
configuration and can be used with either a control
or tributary DSU.
For more information about the 3000 Series Carrier or
the SDCP, refer to the COMSPHERE 3000 Series Carrier,
Installation Manual. For more information about the
6700 Series NMS, refer to the COMSPHERE 6700 Series
Network Management System, User’s Guide. These are
identified in the Related Documents section of the
Preface, which also provides information on how to order
these documents.
Optional Features
The Model 3550 DSU can be ordered with the
following optional features:
•V.32bis 14.4 kbps Dial Backup Module (DBM)
•Time Division Multiplexer (TDM/Flex)
The Model 3551 DSU can be ordered with a V.32bis
14.4 kbps DBM, or it can be used with an external DBU.
If your DSU is not equipped with these options, go to
the next section.
V.32 DBM
The V.32bis 14.4 kbps dial backup module (referred to
as DBM throughout this guide) childboard is attached to
the DSU circuit card. The DBM provides the following
features:
•Multispeed point-to-point backup. The DBM
provides point-to-point service over the 2-wire dial
network. Backup rates available are 2.4, 4.8, 9.6,
12.0, and 14.4 kbps.
•Independent operation. Although the DBM is
installed on the DSU, the two are configured
separately and most tests can be run on either
independent of the other (e.g., you can run a test on
the DBM while a test is running on the DSU).
•Security. There are four levels of call setup
security: None, Password, Callback, and Alarm.
•Management control. Dial backup can be initiated
from a 6700 Series NMS, the DSU’s DCP, or it can
be initiated automatically by the DSU-DBM.
•Automatic setup and restoration. When
configured for automatic backup, the DSU-DBM
initiates dial backup when it detects a failure in the
network, then restores the data path to the DDS
circuit when the network returns to service.

About Your DSU
1-33550-A2-GB20-40 July 1999
2-Port TDM/Flex
The 2-port TDM/Flex is a separate circuit card that
attaches to the Model 3550 DSU. It allows independent
ports to share one standard digital point-to-point facility.
The 2-port TDM/Flex provides the following features:
•Port capacity. This feature permits the DSU to
operate as a digital sharing device and provides two
independent ports. Port 1 is on the DSU and Port 2
is on the 2-port TDM/Flex. Either port can operate
as an EIA-232 or V.35 interface.
•Multiplexing. With this option, time division
multiplexing can be performed using two
independent ports to share one standard DDS
point-to-point circuit.
•Line speeds. The TDM/Flex operates at all line
speeds supported by the DSU: 2.4, 4.8, 9.6, 19.2,
38.4, and 56 kbps. For LADS operation, 64 kbps is
also supported.
•Port speeds. Each port can be set to 1.2, 2.4, 4.8,
9.6, 14.4, 19.2, 48, 56, or 64 kbps. In 2-port
TDM/Flex applications, the sum of the port speeds
cannot exceed the line speed.
•Asynchronous operation. Although the DSU
provides synchronous transmission through the
DDS network, any port can be configured for
asynchronous operation. When the 2-port
TDM/Flex is installed, asynchronous-to-
synchronous conversion can be performed.
Asynchronous data rates of 150, 300, 600, 1200,
and 1800 bps are supported, along with the
synchronous data rates.
•Digital sharing. With this feature, the ports can
share the same channel. All ports in a
digital-sharing group operate at the same speed, and
all receive the same data. When configured for
DSD (digital-sharing device) port contention, only
one port at a time is allowed to send.
•Elastic store per port. A transmit elastic store
buffer is provided for each port for the support of
extended circuits. Both digital and analog
extensions are supported.
•Switched-carrier emulation. In 2-port TDM/Flex
transmission, switched-carrier emulation is optional
for each port, for both the inbound (toward the
control DSU) and outbound (from the tributary
DSU) directions.
•NMS control. Control of a 3550 DSU with 2-port
TDM/Flex can be performed from a 6700 Series
NMS or the DSU’s DCP.
•Point-to-point backup. A 3550 DSU with 2-port
TDM/Flex can also have a DBM installed for
point-to-point dial backup. If backup is at a
different speed than the DSU’s speed, TDM/Flex
operation automatically changes to the lower
speed.
Upgrades Available
Although your DSU may not currently have a DBM or
2-port TDM/Flex installed, you can add these features at a
later time. Both the DBM and 2-port TDM/Flex features
are available as upgrades.
You can order the option you want and install it
yourself (referred to as a field installation). Refer to the
Equipment List in Appendix F for the feature number to
order.
Technical Specifications
Tables 1-1 through 1-4 list the technical specifications
for the following:
•General specifications that apply to all Model 3550
and 3551 circuit cards (Table 1-1)
•Specifications for the Model 3550 and 3551 DSU
only (Table 1-2)
•Specifications for the V.32 DBM (Table 1-3)
•Specifications for the 2-port TDM/Flex ć only used
with a Model 3550 (Table 1-4)

COMSPHERE 3550 Series Data Service Units
1-4 July 1999 3550-A2-GB20-40
Table 1-1
(1 of 2)
General Technical Specifications
Specifications Criteria
APPROVALS
FCC Part 15
FCC Part 68
UL
3550 DSU
3551 DSU, 3000 Series Carrier
CSA
Safety
3550 DSU
3551 DSU, 3000 Series Carrier
Emissions
Bell Canada
Class A digital device
AW292J-61661-DD-N
Listed U L 1950, second edition
Recognized Component UL 1950, second edition
Certified CSA 22.2, No. 950-M89
Certified Component CSA 22.2, No. 950-M89
CSA 108.8 – M1983, Class A digital apparatus
“DCTE Specifications,” July 1989, Issue 1
AC POWER REQUIREMENTS
3550 DSU
3550 DSU with DBM
3550 DSU with 2-Port TDM/Flex
3551 DSU
3551 DSU with DBM
V.32 DBM
3000 Series Carrier (16 DSUs with DBMs
plus SDU and fan module)
24 Vac (CT), 60 Hz +3 (0.093 amp, 5.8 watts at 115 Vac)
24 Vac (CT), 60 HZ ±3 (0.115 amp, 9.5 watts at 115 Vac)
24 Vac (CT), 60 Hz +3 (0.103 amp, 8.6 watts at 115 Vac)
24 Vac (CT), 60 Hz +3 (0.029 amp, 4.5 watts at 115 Vac)
24 Vac (CT), 60 Hz +3 (0.080 amp, 8.0 watts at 115 Vac)
24 Vac (CT), 60 Hz +3 (0.024 amp, 2.0 watts at 115 Vac)
90—132 Vac, 60 Hz +3 (1.650 amp, 165 watts at 115 Vac)
DTE INTERFACE
3550 DSU
25-pin D-subminiature connector
34-pin connector
3551 DSU with
25-Pin V.35 Interface
Uses a Rear Connector Plate with two
25-pin D-subminiature connectors.
EIA-232-D/ITU-T V.24 (ISO 2110)
ITU-T V.35 (ISO 2593)
EIA-232-D/ITU-T V.24 (ISO 2110)
ITU-T V.35 (ISO 2593)
(A V.35 adapter is required to use the V.35 connector. The adapter
provides an interface between the DSU’s 25-pin D-type connector and the
DTE cable’s V.35 connector.)
ENVIRONMENT
Operating Temperature
Storage Temperature
Relative Humidity
Shock and Vibration
32°to 122°F (0°to 50°C)
–4°to 158°F (–20°to 70°C)
5%—95% (noncondensing)
Withstands normal shipping and handling

About Your DSU
1-53550-A2-GB20-40 July 1999
Table 1-1
(2 of 2)
General Technical Specifications
Specifications Criteria
HEAT DISSIPATION (MAX.) AT 115 VAC
3550 DSU
3550 DSU with DBM
3550 DSU with 2-Port TDM/Flex
3551 DSU
3551 DSU with DBM
3000 Series Carrier (16 DSUs with DBMs
plus SDU and fan module)
22.16 Btu/hr
29.00 Btu/hr
29.21 Btu/hr
22.16 Btu/hr
27.30 Btu/hr
563.00 Btu/hr
PORT RATES Async or Sync rates: 64, 56, 48, 19.2, 14.4, 12.0, 9.6, 4.8, 2.4, and
1.2 kbps
Other asynchronous rates (e.g., 150, 300, 600, and 1800 bps) can be
obtained through oversampling
Asynchronous rates support ITU-T V.14 extended rate range at 8 to 12 bits
per character, including the
start and stop bit (+2.3, –2.5 percent
overspeed/underspeed compensation at 10 bits per character)
NMS COMPATIBILITY COMSPHEREr6700 Series NMS, Release 4.0 or greater

COMSPHERE 3550 Series Data Service Units
1-6 July 1999 3550-A2-GB20-40
Table 1-2
DSU Technical Specifications
Specifications Criteria
APPLICATION Full- or half-duplex data transmission via point-to-point or multipoint
DDS network, or local area data channel
COMMUNICATION LINE Leased or private 4-wire DDS line
DATA RATES
Digital Services (DDS, ASDS)
LADS
When timing is external (provided by the
DTE), the DTE’s clock must be within these
ranges.
2.4, 4.8, 9.6, 19.2, 38.4, and 56 kbps
2.4, 4.8, 9.6, 19.2, 38.4, 56, and 64 kbps
64 kbps 11 bps
56 kbps 9 bps
38.4 kbps 4 bps
19.2 kbps 5 bps
9.6 kbps 1 bps
4.8 kbps 0 bps
2.4 kbps 0 bps
DDS NETWORK INTERFACE
3550 DSU
3551 DSU
8-pin modular jack, USOC RJ48S
(One or two) 50-pin connector, USOC RJ48T
DIAGNOSTIC INTERFACE
3550 DSU
3551 DSU
Requires 3600 Series Hubbing Device which provides
two 8-pin modular jacks
Via the SDU in the COMSPHEREr3000 Series Carrier
NETWORK COMPATIBILITY
AT&T Technical Reference 62310 – 1987
Integrated Network Corporation
Compatibility Bulletin CB-INC-101, and
Pacific Bell publications
PUB L-780035-PB/NB and
PUB L-780036-PB/NB
2.4, 4.8, 9.6, and 56 kbps
19.2 kbps loop at levels of +6, 0, or –10 dBm
DSU COMPATIBILITY
Primary Channel All Paradyne digital products and other products that are compliant with
AT&T Technical Reference 62310 – 1987