ADTRAN DSU III TDM User manual

&57"+++"6&/
&CVC"5GTXKEG"7PKV
2CTV"0WODGT"3422285.3
&QEWOGPV"0WODGT"83422285.3/42#
#RTKN"3;;;

Trademarks:
DATAPATH is a registered trademark of CAE electronics and is
used by Northern Telecom under license.
901 Explorer Boulevard
P.O. Box 140000
Huntsville, AL 35814-4000
[phone]
© 1999 ADTRAN, Inc.
All Rights Reserved.
Printed in U.S.A.

iii
FCC regulations require that the following information be provided in
this manual:
1. This equipment complies with Part 68 of the FCC rules. On the bot-
tom of the equipment housing is a label that shows the FCC registra-
tion number and Ringer Equivalence Number (REN) for this
equipment. If requested, provide this information to the telephone
company.
2. If this equipment causes harm to the telephone network, the tele-
phone company may temporarily discontinue service. If possible,
advance notification is given; otherwise, notification is given as soon
as possible. The telephone company will advise the customer of the
right to file a complaint with the FCC.
3. The telephone company may make changes in its facilities, equip-
ment, operations, or procedures that could affect the proper opera-
tion of this equipment; advance notification and the opportunity to
maintain uninterrupted service is given.
4. If experiencing difficulty with this equipment, please contact ADT-
RAN for repair and warranty information. The telephone company
may require this equipment to be disconnected from the network
until the problem is corrected or it is certain the equipment is not
malfunctioning.
5. This unit contains no user serviceable parts.
6. An FCC compliant telephone cord with a modular plug is provided
with this equipment. This equipment is designed to be connected to
the telephone network or premises wiring using an FCC compatible
modular jack, which is Part 68 compliant.
7. The following information may be required when applying to the
local telephone company for leased line facilities.
8. In the event of equipment malfunction, all repairs should be per-
formed by ADTRAN. It is the responsibility fo users requiring ser-
vice to report the need for service to their distributor or ADTRAN.
See the inside back cover of this manual for information on contact-
ing ADTRAN for service.
Service Type Digital Facility Interface Code Service Order Code Network Jacks
56 kbps Digital Interface 04DU5-56 6.0F RJ-48S
64 kbps Digital Interface 04DU5-64 6.0F RJ-48S

iv
FEDERAL COMMUNICATIONS COMMISSION RADIO FREQUENCY
INTERFERENCE STATEMENT
This equipment has been tested and found to comply with the limits for a
Class A digital device, pursuant to Part 15 of the FCC Rules. These limits
are designed to provide reasonable protection against harmful interfer-
ence when the equipment is operated in a commercial environment. This
equipment generates, uses, and can radiate radio frequency energy and, if
not installed and used in accordance with the instructions, may cause
harmful interference to radio frequencies. Operation of this equipment in
a residential area is likely to cause harmful interference in which case the
user will be required to correct the interference at his own expense.
Shielded cables must be used with this unit to ensure compliances with
Class A FCC limits.
CANADIAN EMISSIONS REQUIREMENTS
This digital apparatus does not exceed the Class A limits for radio noise
emissions from digital apparatus as set out in the interference-causing
equipment standard entitled "Digital Apparatus," ICES-003 of the Depart-
ment of Communications.
Cet appareil nuerique respecte les limites de bruits radioelectriques appli-
cables aux appareils numeriques de Class A prescrites dans la norme sur
le materiel brouilleur: "Appareils Numeriques," NMB-003 edictee par le
ministre des Communications.
Changes or modifications to this unit not expressly approved
by ADTRAN will void the user's authority to operate the
equipment.

v
CANADIAN EQUIPMENT LIMITATIONS
Notice: The Canadian Industry and Science Canada label identifies certi-
fied equipment. This certification meansthat the equipmentmeets certain
telecommunications network protective, operational, and safety require-
ments. The Department does not guarantee the equipment will operate to
the user’s satisfaction.
Before installing this equipment, ensure that it is permissible to be con-
nected to the facilities of the local telecommunications company. The
equipment must also be installed using an acceptable method of connec-
tion. In some cases, the company’s inside wiring associated with a single-
line individual service may be extended by means of a certified connector
assembly (telephone extension cord). Compliance with the above condi-
tions may not prevent degradation of service in some situations.
Repairs to certified equipment should be made by an authorized Canadi-
an maintenance facility designated by the supplier. Any repairs or alter-
ations made by the user to this equipment, or equipment malfunctions,
may give the telecommunications company cause to request the user to
disconnect the equipment.
Users should ensure for their own protection that the electrical ground
connections of the power utility, telephone lines, and internal metallic wa-
ter pipe system, if present, are connected together. This precaution may be
particularly important in rural areas.
The Load Number (LN) assigned to each terminal device denotes the per-
centage of the total load to be connected to a telephone loop which is used
by the device, to prevent overloading. The termination on a loop may con-
sist of any combination of devices subject only to the requirement that the
total of the Load Numbers of all devices does not exceed 100.
Users should not attempt to make such connections themselves,
but should contact the appropriate electric inspection authority,
or an electrician, as appropriate.

vi
IMPORTANT SAFETY INSTRUCTIONS
When using your telephone equipment, please follow these basic safety
precautions to reduce the risk of fire, electrical shock, or personal injury:
1. Do not use this product near water, such as near a bath tub, wash
bowl, kitchen sink, laundry tub, in a wet basement, or near a swim-
ming pool.
2. Avoid using a telephone (other than a cordless-type) during an elec-
trical storm. There is a remote risk of shock from lightning.
3. Do not use the telephone to report a gas leak in the vicinity of the
leak.
4. Use only the power cord, power supply, and/or batteries indicated in
the manual. Do not dispose of batteries in a fire. They may explode.
Check local codes for any special disposal instructions.
SAVE THESE INSTRUCTIONS!
ADTRAN YEAR 2000 (Y2K)
READINESS DISCLOSURE
ADTRAN has established a Year 2000 program to ensure that our prod-
ucts and operations will correctly function in the new millenium. ADT-
RAN warrants that all products meet Year 2000 specifications regardless
of model or revision. Information about ADTRAN’s Year 2000 compli-
ance program is available at the following:
Web Site www.adtran.com
Product Matrix www.adtran.com/Y2Kfax.html
Faxback Document Line [phone]
Y2K plans and product certifications
are listed in the matrix
Y2K Project Line [phone]
E-Mail year 200[email protected]

61200063L1-20 DSU III TDM User Manual vii
Table of Contents
List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xiii
List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xv
Chapter 1. Introduction
Product Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
DDS Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Dial Backup Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Overview of Dial Backup Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
4-Wire Switched 56 Backup Option . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
2-Wire Switched 56 Backup Option . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
V.32 bis Backup Option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
1B+D Basic Rate ISDN Backup Option . . . . . . . . . . . . . . . . . . . . . . . . 1-4
Entering Dial Backup Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
Loss of Sealing Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
Out of Service (OOS) Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
No Receive Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
All 1s or all 0s Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
Conditions for Returning to the DDS Circuit . . . . . . . . . . . . . . . . . . . . 1-6
Warranty and Customer Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
Chapter 2. Installation
Unpack, Inspect, Power Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Receipt Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
ADTRAN Shipments Include . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Customer Provides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Power Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Network Connection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Telco Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Control Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
DTE Connection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
Remote Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

viii DSU III TDM User Manual 61200063L1-20
Table of Contents
Chapter 3. Operation
Menu Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1
Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2
Network Rate, DTE Rate, and Data Format . . . . . . . . . . . . . . . . . . . .3-2
Dial Backup Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-3
Type of Dial Backup Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-3
Current Status of Dial Backup Mode . . . . . . . . . . . . . . . . . . . . . . . .3-3
Multiplexer Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-5
Errored Seconds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-5
DSU and Network Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-6
Current DSU III TDM Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-6
Current DDS Network Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-6
Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-7
Configuration (CONFIG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-7
Dial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-7
Basic Menu Travel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-8
Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-10
LCD Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-10
Enter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-10
Numeric Keypad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-10
Shift . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-10
Quick . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-11
Cancel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-11
Up and Down Arrows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-11
LED Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-11
Rear Panel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-13
Chapter 4. Testing and Troubleshooting
Test Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-1
Initiating a Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-3
Test Status Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-4
Exiting a Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-4
Local Unit diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-6
DTE & Loop (LL). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-7
Test Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-7
Test Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-8
Initiating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-8
Interpreting Test Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-8
Loop Only (RT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-9
Test Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-9

61200063L1-20 DSU III TDM User Manual ix
Table of Contents
Initiating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10
Interpreting Test Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10
DTE Only . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11
Test Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12
Initiating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12
Interpreting Test Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12
DTE With Test Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13
Test Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14
Initiating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14
Test Pattern Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14
Interpreting Test Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15
Test Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16
Test Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17
Initiating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17
Interpreting Test Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17
Self Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
Test Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
Initiating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
Interpreting Test Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
Remote Unit Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-20
Test Patterns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-20
Data from DTE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-21
Port RDL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-22
Test Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-22
Initiating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-23
Test Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-23
Interpreting Test Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-23
DBU Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-24
Test Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-25
Initiating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-25
Interpreting Test Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-25
Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-26
Messages from the DSU/CSU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-26
Chapter 5. Configuration Overview
Local and Remote Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
Chapter 6. Configuring Network Options
Network Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
Loop Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

x DSU III TDM User Manual 61200063L1-20
Table of Contents
Clock Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-3
Remote Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-4
Chapter 7. Configuring DTE Options
Dte Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-1
DTE Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-1
Port Not Used . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-2
DTE Pass Through Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-2
Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-3
Transmit Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-4
Clear to Send (CS) Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-5
Forced On . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-5
Follows RS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-5
Carrier Detect (CD) Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-6
Forced On . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-6
Normal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-6
Data Set Ready (SR) Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-7
Forced On . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-7
Off OOS Only . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-7
Off Test Only . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-7
Off Test+OOS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-7
Off Remt Idle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-7
Chapter 8. Configuring Test Options
Test Options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-1
Test Timeout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-1
Remote Digital Loopback (RDL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-2
DBU Answer Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-3
Chapter 9. Configuring Dial Options
Dial Options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-1
Phone Number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-3
ISDN Dial Backup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-3
Setting the Service Profile Identifier (SPID) . . . . . . . . . . . . . . . . . . . .9-3
Setting the Local Directory (LOC) Number . . . . . . . . . . . . . . . . . . . .9-4
Dial Backup Options for All Models . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-4
Automatic DBU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-4
Number to Dial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-4
Originate/Answer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-4
When Out of Service (OOS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-4

61200063L1-20 DSU III TDM User Manual xi
Table of Contents
No Receive (RX) Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-4
No Sealing Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-5
When all 1s/0s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-5
Auto Restore . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-5
Redial Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-5
Fail Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-5
Wait to Redial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-6
2-Wire and 4-Wire Dial Backup Options . . . . . . . . . . . . . . . . . . . . . . . . 9-6
Network Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-6
V.32 bis Dial Backup Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-6
Error Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-6
Flow Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-7
Compression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-7
ISDN Dial Backup Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-8
Switch Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-8
Chapter 10. Manual Command
Manual Command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1
Chapter 11. Dial Options
Dial Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-1
Answer Unit Connected to DDS Line . . . . . . . . . . . . . . . . . . . . . . . . 11-2
Dial Backup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-2
Originate Unit Connected to DDS Line . . . . . . . . . . . . . . . . . . . . . . 11-2
Dial Backup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-2
Stay on Leased . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-2
DBU Online Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-2
Dial Options During Dial Backup . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-2
Hang Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-2
Stay On Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-2
Appendix A. Pinouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-1
Appendix B. Configuration Profiles . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-1
Appendix C. DSU to Modem Interconnect. . . . . . . . . . . . . . . . . . . . . . .C-1
Appendix D. EIA-232 Connector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D-1
Appendix E. Specifications Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . E-1

xii DSU III TDM User Manual 61200063L1-20
Table of Contents
Appendix F. Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-1
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

61200063L1-20 DSU III TDM User Manual xiii
List of Figures
Figure 1-1. Sample 64 kbps Application for the DSU III TDM . . . . . . . 1-2
Figure 3-1. Status Display Example. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
Figure 3-2. Example of Basic Menu Travel. . . . . . . . . . . . . . . . . . . . . . . . 3-9
Figure 3-3. DSU III TDM Front View . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10
Figure 3-4. DSU III TDM Rear View . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13
Figure 4-1. Normal Operation Before Initiating Loopback Test . . . . . . 4-2
Figure 4-2. Initiating a Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
Figure 4-3. Sample Test Status Displays. . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
Figure 4-4. Complete Test Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5
Figure 4-5. DTE & Loop Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7
Figure 4-6. Initiating a DTE & Loop Test . . . . . . . . . . . . . . . . . . . . . . . . . 4-8
Figure 4-7. Loop Only Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9
Figure 4-8. Initiating a Loop Only Test. . . . . . . . . . . . . . . . . . . . . . . . . . 4-10
Figure 4-9. DTE Only Test Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11
Figure 4-10. Initiating a DTE Only Test . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12
Figure 4-11.DTE with Test Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13
Figure 4-12. Initiating a DTE Test with Test Pattern. . . . . . . . . . . . . . . . 4-14
Figure 4-13.Test Pattern Only . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16
Figure 4-14. Initiating a Test Using a Test Pattern . . . . . . . . . . . . . . . . . 4-17
Figure 4-15.Initiating a Self Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
Figure 4-16. V.54 Remote Digital Loopback w/Test Pattern. . . . . . . . . 4-21
Figure 4-17.Port RDL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-22
Figure 4-18.Initiating a Remote Test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-23
Figure 4-19.DBU Connection Test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-24
Figure 4-20. Initiating a DBU Connection Test . . . . . . . . . . . . . . . . . . . . 4-25
Figure 6-1. Setting Loop Rate Options . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
Figure 6-2. Setting the Clock Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3
Figure 6-3. Enabling/Disabling Remote Configuration. . . . . . . . . . . . . 6-4
Figure 7-1. DTE Rate Options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2
Figure 7-2. Selecting Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3
Figure 7-3. Transmit Clock Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4
Figure 7-4. Selecting Clear to Send (CS) Options . . . . . . . . . . . . . . . . . . 7-5
Figure 7-5. Selecting Carrier Detect (CD) Options . . . . . . . . . . . . . . . . . 7-6

xiv DSU III TDM User Manual 61200063L1-20
List of Figures
Figure 7-6. Setting Data Set Ready (SR) Options . . . . . . . . . . . . . . . . . . .7-7
Figure 8-1. Setting Test Timeout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-1
Figure 8-2. Remote Digital Loopback. . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-2
Figure 8-3. DBU Answer Test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-3
Figure 9-1. Dial Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-2
Figure 9-2. Editing a Stored Phone Number . . . . . . . . . . . . . . . . . . . . . . .9-3
Figure 10-1.Manual Command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10-1
Figure 11-1.Dial Options Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11-1
Figure C-1. DSU III TDM to Modem Interconnect . . . . . . . . . . . . . . . . . C-1
Figure D-1. EIA-232 Connector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-1

61200063L1-20 DSU III TDM User Manual xv
List of Tables
Table 3-1. Quick Key Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11
Table 4-1. Test Selections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
Table 4-2. Remote Tests Selections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-20
Table 4-3. Messages from the DSU/CSU . . . . . . . . . . . . . . . . . . . . . . . 4-27
Table 10-1. Manual Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-2
Table A-1. Pin Assignments for EIA-232 Connectors. . . . . . . . . . . . . . .A-1
Table A-2. Pin Assignments for Main Connector . . . . . . . . . . . . . . . . . .A-2
Table A-3. Pin Assignments for Backup Connector. . . . . . . . . . . . . . . .A-2
Table A-4. V.35 Pin Assignments for Adapter Cable. . . . . . . . . . . . . . .A-4
Table A-5. EIA-232 Pin Assignments for Adapter Cable. . . . . . . . . . . .A-5
Table B-1. Default Configuration for the DSU III TDM . . . . . . . . . . . . B-2

xvi DSU III TDM User Manual 61200063L1-20
List of Tables

61200063L1-20 DSU III TDM User Manual 1-1
Chapter 1 Introduction
PRODUCT OVERVIEW
The ADTRAN DSU III TDM (time division multiplexer) enables the user
to run four DTE ports over a single 56/64 kbps Digital Data Service (DDS)
circuit. One communications link is shared by up to four DTE devices by
enabling each DTE to use the path exclusively at regular intervals. In this
way a circuit capable of a relatively high information transfer rate is sub-
divided into time slots to provide a number of lower speed channels.
Figure 1-1 on page 1-2 shows an example of a typical application using the
DSU III TDM on a 64 kbps network. Each of the four DTE devices is al-
lowed a portionof the dedicatedcircuit, not exceedingthe allowable band-
width of 60.8 kbps.
The major capabilities of the DSU III TDM include:
• 56/64 kbps leased line point-to-point DDS operation
• Four independent DTE ports
• Synchronous or asynchronous operation on all ports
• Single port operation
• Automatic remote configuration for critical options
• Optional dial backup capability (4-wire Switched 56, 2-wire Switched
56, ISDN, or V.32 bis)
• Extensive test functions for testing of DTE & Loop interfaces
• Extensive status monitoring

Chapter 1. Introduction
1-2 DSU III TDM User Manual 61200063L1-20
Figure 1-1. Sample 64 kbps Application for the DSU III TDM
DDS OPERATION
DDS is a nationwide service that allows interconnection and transport of
data at speeds up to 64kbps. The local exchange carriers provide the local
loop service to DDS customers and may provide data for routing Inter-
LATA to an interexchange carrier. In DDS mode, the DSU III TDM sup-
ports the 56/64 kbps DDS service rate.
DDS NETWORK
CENTRAL OFFICE
64K Loop Rate
DSU III TDMDSU III TDM
1
2
3
4
Port
1
2
3
4
Port
SWITCH
ENTER
123
456
789
#0
*
RS CS TD RD LD TR SR
ISU128
CANCEL
ENTER
123
456
789
#0
*
RS CS TD RD LD TR SR
ISU128
CANCEL
Optional
Switched
Backup
Optional
Switched
Backup 38.4K
9.6K
9.6K
2.4K
38.4K
9.6K
9.6K
2.4K

Chapter 1. Introduction
61200063L1-20 DSU III TDM User Manual 1-3
DIAL BACKUP OPERATION
The DSU III TDM may be configured with optional dial backup cards.
This allows the TDM to back up the DDS circuit in the event of an inter-
ruption. The TDM supports dial backup operation over 4-wire Switched
56, 2-Wire Switched 56, 1B+D ISDN, or analog (V.32 bis) public service
telephone network (PSTN) when equipped with the appropriate dial
backup module.
Contact your local telco provider to determine which services are avail-
able for your location.
The DSU III TDM equipped with a Switched 56 or ISDN module can auto-
matically or manually back up all four ports in the event of a DDS circuit
failure. Upon restoration of the DDS circuit, the DSU III TDM can be au-
tomatically or manually returned to dedicated operation.
When using analog V.32 bis backup, only port 1 is backed up.
When operating at a DDS loop rate of 64 kbps, the TDMis capable of back-
ing up all four ports over the Switched 56 service if no more than 52.8 kbps
of bandwidth has been allocated to the ports.
If more than 52.8 kbps of bandwidth has been allocated to the four ports,
the TDM turns off ports during dial backup until the 52.8 kbps limit is not
exceeded. Ports are turned off in the sequence 4, 3, and 2. For example, in
Figure 1-1 on page 1-2, ports 3 and 4 would be turned off during dial back-
up.
Overview of Dial Backup Options
4-Wire Switched 56 Backup Option
This 4-Wire Switched 56 Service allows customers to pay for data connec-
tion only for the time the unit is active. The regional operating companies
provide the 4-wire local loop service to SW56 customers.

Chapter 1. Introduction
1-4 DSU III TDM User Manual 61200063L1-20
2-Wire Switched 56 Backup Option
DATAPATH®is a Switched 56 service offered under various service
names by the local service provider. The services are generally provided
by the Northern Telecom DMS/SL100 family of central office switches.
DATAPATH allows the customer to pay for high speed data transfer, up
to 56 kbps, only when the unit is active. The dial up service is delivered
via a 2-wire local loop that can be up to 18,000 feet at a signal level of
-45dB.
V.32 bis Backup Option
The V.32 bis/42 bis modem in an asynchronous mode can use V.42 bis
data compression to make up for a slower connection rate. V.42 bis in-
creases the effective data throughput from 14.4 kbps to as high as 57.6
kbps, depending on the data type. No compression is supported in syn-
chronous operation.
Due to the limited bandwidth of the V.32 modem, employing this type of
service limits dial backup to only PORT 1. PORT 1 is backed up to a max-
imum of 14.4 kbps synchronous. For asynchronous operation,the backup
module may be configured to employ data compression so data rates
higher than 14.4 kbps may be supported.
1B+D Basic Rate ISDN Backup Option
ISDN service provides the customer with a switched 56/64 kbps circuit.
The default data rate for this option is 56 kbps. The 64 kbps data rate may
be accessed using the Smart Dial String as described in the chapter Config-
uring Dial Options on page 9-1. This option provides a U interface to the
ISDN network.