ADTRAN TSU 120 User manual

TSU 120
PART NUMBER 1200129L1
USER MANUAL
61200.129L1-1A
July 1997

901 Explorer Boulevard
P.O. Box 140000
Huntsville, AL 35814-4000
Phone: [phone]
© 1997 ADTRAN, Inc.
All rights reserved.
Printed in USA.

FCC regulations require that the following information be provided to the
customer in this manual:
1. This equipment complies with Part 68 of the FCC rules. The required label is affixed
to the bottom of the chassis.
2. 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 which is Part 68 compliant. See
Installation Instructions for details.
3. If your telephone equipment TSU 120 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 isn’t practical, you will be notified as
soon as possible. You will be advised of your right to file a complaint with the FCC.
4. Your telephone company may make changes in its facilities, equipment, operations, or
procedures that could affect the proper operation of your equipment. If they do, you
will be given advance notice so as to give you an opportunity to maintain
uninterrupted service.
5. If you experience trouble with this equipment TSU 120, please contact ADTRAN at
[phone] for repair/ warranty information. The telephone company may ask
you to disconnect this equipment from the network until the problem has been
corrected, or until you are sure the equipment is not malfunctioning.
6. This unit contains no user-serviceable parts.
7. The following information may be required when applying to your local telephone
company for leased line facilities.
Digital Facility Service Order Network
Service Type Interface Code Code Jacks
1.544 Mbps Digital Interface SF 04DU9-BN 6.0F RJ-48C
1.544 Mbps Digital Interface SF with B8ZS 04DU9-DN 6.0F RJ-48C
1.544 Mbps Digital Interface ESF 04DU9-1KN 6.0F RJ-48C
1.544 Mbps Digital Interface ESF with B8ZS 04DU9-1SN 6.0F RJ-48C
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 interference 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 instruction manual, 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 compliance with Class A FCC limits.
Change or modifications to this unit not expressly approved by the
party responsible for compliance could void the user’s authority to
operate the equipment.

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AFFIDAVIT REQUIREMENTS
FOR CONNECTION TO DIGITAL SERVICES
• An affidavit is required to be given to the telephone company
whenever digital terminal equipment without encoded analog
content and billing protection is used to transmit digital signals
containing encoded analog content which are intended for
eventual conversion into voiceband analog signals and
transmitted on the network.
• The affidavit shall affirm that either no encoded analog content or
billing information is being transmitted or that the output of the
device meets Part 68 encoded analog content or billing
protection specifications.
• End user/customer will be responsible to file an affidavit with the
local exchange carrier when connecting unprotected CPE to a
1.544 Mbps or subrate digital services.
• Until such time as subrate digital terminal equipment is
registered for voice applications, the affidavit requirement for
subrate services is waived.

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AFFIDAVIT FOR CONNECTION OF CUSTOMER PREMISES
EQUIPMENT TO 1.544 MBPS AND/OR SUBRATE DIGITAL SERVICES
For the work to be performed in the certified territory of _______________
(telco name)
State of ________________
County of ________________
I, _____________________________ (name), _____________________
(business address), ____________________ (telephone number) being
duly sworn, state:
I have responsibility for the operation and maintenance of the terminal
equipment to be connected to 1.544 Mbps and/or ________ subrate digital
services. The terminal equipment to be connected complies with Part 68 of
the FCC rules except for the encoded analog content and billing
protection specifications. With respect to encoded analog content and
billing protection:
( ) I attest that all operations associated with the establishment, mainte-
nance, and adjustment of the digital CPE with respect to analog content
and encoded billing protection information continuously complies with Part
68 of the FCC Rules and Regulations.
( ) The digital CPE does not transmit digital signals containing encoded
analog content or billing information which is intended to be decoded within
the telecommunications network.
( ) The encoded analog content and billing protection is factory set and is
not under the control of the customer.
I attest that the operator(s)/maintainer(s) of the digital CPE responsible for
the establishment, maintenance, and adjustment of the encoded analog
content and billing information has (have) been trained to perform these
functions by successfully having completed one of the following ( check
appropriate blocks ):

Table of Contents
( ) A. A training course provided by the manufacturer/grantee of the
equipment used to encode analog signals; or
( ) B. A training course provided by the customer or authorized
representative, using training materials and instructions provided by the
manufacturer/grantee of the equipment used to encode analog signals; or
( ) C. An independent training course (e.g., trade school or technical
institution) recognized by the manufacturer/grantee of the equipment used
to encode analog signals; or
( ) D. In lieu of the preceding training requirements, the operator(s)/
maintainer(s) is (are) under the control of a supervisor trained in
accordance with _________ ( circle one ) above.
I agree to provide _________________ (telco's name) with proper
documentation to demonstrate compliance with the information as provided
in the preceding paragraph, if so requested.
_________________________________Signature
_________________________________Title
_________________________________ Date
Transcribed and sworn to before me
This ________ day of ________, 199___
_________________________________
Notary Public
My commission expires:
_________________________________

Table of Contents
61200.129L1-1 TSU 120 User Manual i
Table of Contents
Chapter 1. Introduction
TSU 120 Overview ..............................................................................................1
Functional Description ...............................................................................1
TSU ...................................................................................................1
TSU 100 ............................................................................................2
TSU 120 ............................................................................................2
TSU 600 ............................................................................................2
Identification of Rear Panel Layout .................................................................3
Features of the TSU 120 ..............................................................................5
Interfaces.......................................................................................................6
TSU 120 Interfaces ..............................................................................................7
Network Interface........................................................................................7
DSX-1 (PBX) Interface .................................................................................7
Nx56/64 Serial Interface.............................................................................7
Control Port Input .......................................................................................8
Chain Port Output.......................................................................................8
Option Ports ........................................................................................................9
Secondary Interfaces (SI) ............................................................................9
Other Data Interfaces ..................................................................................9
Dial Backup ..................................................................................................9
Four Methods of Control .................................................................................10
Front Panel .................................................................................................10
ADTRAN PC Program .............................................................................10
SNMP ..........................................................................................................10
Terminal Mode ..........................................................................................10
TSU 120 Clock Sources..................................................................................... 11
Network Timed..........................................................................................11
DSX-1 Timed ..............................................................................................12
DTE Timed .................................................................................................13
Internal Timing ..........................................................................................14
Normal (CSU) Timing...............................................................................15
TSU 120 Testing.................................................................................................16
Self Tests .....................................................................................................16
Loopback Tests ..........................................................................................16
Classes of Loopbacks .........................................................................17
Network Interface Loopbacks ...................................................17
DTE Interface Loopbacks ...........................................................17
DSX-1 Interface Loopbacks........................................................19

Table of Contents
ii TSU 120 User Manual 61200.129L1-1
Pattern Generation .............................................................................20
QRSS Pattern................................................................................20
511 Pattern ....................................................................................20
Chapter 2. Installation
Unpack, Inspect, Power Connection..............................................................21
Shipped by ADTRAN ...............................................................................21
Provided by Customer..............................................................................21
Power Connection .....................................................................................22
Warranty and Customer Service ....................................................................23
Grounding Instructions (UL 1459) .................................................................24
Wiring ................................................................................................................. 26
Network ......................................................................................................26
Connections.........................................................................................26
Control In/Chain In ..................................................................................27
Connections.........................................................................................27
Chain Out ...................................................................................................28
Connections.........................................................................................28
Nx56/64 DTE (V.35)..................................................................................29
Connections.........................................................................................29
Base DSX-1 (PBX) ......................................................................................30
Power Up Testing and Initialization ..............................................................31
Self Test .......................................................................................................31
Set User Passcode ......................................................................................32
To Establish a Passcode .....................................................................32
Special Feature.............................................................................32
No Passcode Desired .........................................................................33
Set Unit Identification Number ...............................................................34
To Set the Unit Identification............................................................34
No Unit ID Desired ............................................................................34
Set Control Port..........................................................................................35
Control In (PC)....................................................................................35
Chain In ...............................................................................................35
Normal Power-Up Procedure..................................................................37
Correct Passcode ................................................................................37
Incorrect Passcode..............................................................................37
No Passcode ........................................................................................37

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61200.129L1-1 TSU 120 User Manual iii
Chapter 3. Operation
Operation ...........................................................................................................39
Identification of Front Panel Layout.......................................................39
Display Panels ....................................................................................40
Remote ..........................................................................................40
DSU/DSX Status ........................................................................40
LCD Window ...............................................................................40
Module Status..............................................................................40
CSU Status....................................................................................41
Operation Keys ...................................................................................41
Copy ..............................................................................................41
Remote ..........................................................................................41
Home.............................................................................................41
Alarm ............................................................................................41
Shift ...............................................................................................41
Clear ..............................................................................................41
Cancel ...........................................................................................41
Enter ..............................................................................................42
Up and Down Arrows ................................................................42
Keypad..........................................................................................42
A,B,C,D,E,F ..................................................................................42
2 .....................................................................................................42
General Menu Operation .........................................................................43
Select and Activate a Menu Item .....................................................43
Set the Data Field................................................................................44
Display Only Data Fields ..................................................................45
Exit Any Menu Field Operation or Display ...................................45
Data Port Identification ............................................................................46
Menu Structure .................................................................................................47
Opening Menu Functions.........................................................................48
Status ....................................................................................................48
Network Interface Performance Reports (NI PERF RPTS) ...48
Network Interface (NI) Errors ...................................................48
Active Alarms ..............................................................................48
View History ................................................................................49
Port Status ....................................................................................49
Remote Port .................................................................................49
Configuration (CONFIG) ..................................................................49
Network (NI) ...............................................................................49
Unit................................................................................................49
Map Exchange (Map XCHANG) ..............................................49
Map In Use ...................................................................................49

Table of Contents
iv TSU 120 User Manual 61200.129L1-1
DS0 Map: A (B) ...........................................................................49
Port Configuration (Port Config)..............................................49
Utility (UTIL) ......................................................................................50
Time/Date ....................................................................................50
Factory Restore ............................................................................50
Set Passcode .................................................................................50
Unit ID ..........................................................................................50
Software Revision (Software REV) ...........................................50
Port Utility (Port UTIL) ..............................................................50
Test .......................................................................................................51
Network Tests ..............................................................................51
Run Self Test.................................................................................51
Port Test ........................................................................................51
Cancel Tests..................................................................................51
Detailed Menu Operation................................................................................52
Status ...........................................................................................................52
Network Performance Reports (NI PERF RPTS) ..................................53
Network Interface Errors (NI ERRORS) ................................................55
Active Alarms ............................................................................................56
View History ..............................................................................................57
Port Status...................................................................................................58
Port Status of Nx56/64 ......................................................................58
Operations....................................................................................58
0.1 Nx56/64 Menu Items ...........................................................58
0.2 DSX-1 Menu Items: DSX-1 Errors......................................59
Remote Port .................................................................................59
Configuration (CONFIG) .........................................................................61
Network (NI) ......................................................................................62
Operation .....................................................................................62
Network (NI) Menu Items .........................................................62
Unit.......................................................................................................64
Operation .....................................................................................64
Unit Menu Items .........................................................................64
Map Exchange (Map Xchng) ............................................................65
Operation .....................................................................................65
Map Exchange (Map Xchng) Menu Items...............................65
Map In Use ..........................................................................................67
Operation .....................................................................................67
DS0 Map A and DS0 Map B..............................................................68
Operation .....................................................................................68
DS0 Map A and Map B Menu Items.........................................68

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61200.129L1-1 TSU 120 User Manual v
Port Configuration (Port Config) ............................................................72
Operation.............................................................................................72
0.1 Nx56/64 Port Configuration (Port Config) Menu Items ........73
Rate 56/64 ....................................................................................73
TX CLK .........................................................................................73
DATA.............................................................................................73
CTS ................................................................................................73
DCD ..............................................................................................74
DSR................................................................................................74
0 INHIB.........................................................................................74
INBAND .......................................................................................74
0.2 DSX-1 Port Configuration (Port Config) Menu Items....................75
Format...........................................................................................75
Code ..............................................................................................75
Yellow Alarm ...............................................................................75
Line Length (ft)............................................................................75
In-band Loopback (INBAND LPBACK)..................................75
Robbed Bit Signaling ..................................................................75
Utility (UTIL).....................................................................................................76
Time/Date ..................................................................................................77
Operation.............................................................................................77
Summary for Editing Time/Date ....................................................77
Factory Restore ..........................................................................................78
Operation.............................................................................................78
Set Passcode ...............................................................................................79
Enter Passcode from Other Menus ..................................................79
Change/Set a Passcode .....................................................................79
Unit ID: ID .................................................................................................80
Operation.............................................................................................80
Software Revision (Software Rev) ..........................................................81
Operation.............................................................................................81
Port Utility ..................................................................................................82
Operation.............................................................................................82
Test ......................................................................................................................83
Network Tests ............................................................................................84
Operation.............................................................................................84
Network Tests Menu Items...............................................................84
Local Loopbck .............................................................................84
Remote Loopbck..........................................................................85
Pattern...........................................................................................86
Pattern Result ..............................................................................86

Table of Contents
vi TSU 120 User Manual 61200.129L1-1
Run Selftest.................................................................................................88
Operation.............................................................................................88
Port Tests ....................................................................................................89
Operation.............................................................................................89
Port Test Menu Items for 0.1 Nx56/64............................................89
LOOPBK .......................................................................................89
511 PATT .......................................................................................90
DIS 511 RESLT .............................................................................90
Port Test Menu Items for 0.2 DSX-1 ................................................90
Loopback ......................................................................................90
Cancel Tests................................................................................................90
Chapter 4. Example Operations
Voice and Data Mix ..........................................................................................91
Steps to Set Up Voice and Data Mix...............................................................92
Prior to Step 1.............................................................................................92
Step 1. Configure the Network................................................................92
Step 2. Configure DTE Port: (0.1 - Nx56/64) .........................................93
Step 3. Select the number of DS0s/Port 12 ........................................93
Step 4: Complete the DS0 Map Configuration ......................................94
Step 5: Complete a Configuration Table for the Base DSX-1 Port......95
Step 6: Activate Configuration Menu .....................................................95
Configuring the Network Interface ...............................................................96
Configuring the DS0 Map ...............................................................................98
Temporary Map ..............................................................................................100
Review.......................................................................................................100
Edit.............................................................................................................101
Configuring the Ports .............................................................................103
Testing Example..............................................................................................105
Far End Looped Back Test .....................................................................105
Network Interface Test ....................................................................105
Test the Nx56/64 Interface .............................................................110
Test Termination ........................................................................ 110
Appendix A. TSU 120 Menu Tree.............................................................. 111
Appendix B. DTE Data Rate Table ............................................................113
Appendix C. System Configurations Chart
Step 1: Configure Network ...................................................................115
Step 2: Configure DTE PORT: (0.1 Nx56/64). ...................................116
Step 3: Select number of DS0s/PORT. ................................................116
Step 4: DS0 Map A Configuration........................................................117
Step 5: DS0 Map B Configuration. .......................................................117

Table of Contents
61200.129L1-1 TSU 120 User Manual vii
Appendix D. TSU 120 System Messages
Alarm Messages..............................................................................................120
Network Interface (NI) ...........................................................................120
Nx56/64 Interface....................................................................................120
DSX-1 (PBX) Interface .............................................................................121
Status Messages ..............................................................................................122
Network Interface (NI) ...........................................................................122
Nx56/64 Interface....................................................................................122
DSX-1 (PBX) Interface .............................................................................123
Index.................................................................................................................125
Figures
Figure 1-1. Front View of the TSU 120 ...........................................................1
Figure 1-2. TSU 120 Rear Panel .......................................................................3
Figure 1-3. TSU 120 Interfaces.........................................................................6
Figure 1-4. Network Timed Clock Source ................................................... 11
Figure 1-5. DSX-1 Timed Clock Source ........................................................12
Figure 1-6. DTE Clock Source .......................................................................13
Figure 1-7. Internal Clock Source .................................................................14
Figure 1-8. Normal (CSU) ..............................................................................15
Figure 1-9. Network Loopback Tests ...........................................................17
Figure 1-10. DTE Interface Loopback.............................................................18
Figure 1-11. Port Interface Loopback .............................................................19
Figure 1-12. Diagram of Loopbacks ...............................................................20
Figure 2-1. Example of Chain In ...................................................................36
Figure 3-1. TSU 120 Front Panel Layout ......................................................39
Figure 3-2. Select a Menu Item......................................................................44
Figure 3-3. Sample Menu ...............................................................................44
Figure 3-4. Display and Data Fields .............................................................45
Figure 3-5. Menu Tree: The Four Opening Menus ....................................47
Figure 3-6. Display of Opening Main Menus .............................................48
Figure 3-7. Status Menu Tree .........................................................................52
Figure 3-8. Network Interface Performance Report...................................53
Figure 3-9. Network Interface Error Type ...................................................55
Figure 3-10. Display of Alarm Messages .......................................................56
Figure 3-11. Configuration Menu Tree...........................................................61
Figure 3-12. Map Exchange Selection Display..............................................65
Figure 3-13. Selection Times for Map Exchange ...........................................66
Figure 3-14. DS0 Map Designations ...............................................................68
Figure 3-15. CREATE TEMP Selection Screen ..............................................69
Figure 3-16. Selected Port and Quantity of DS0s .........................................70
Figure 3-17. Port Configuration ......................................................................72

Table of Contents
viii TSU 120 User Manual 61200.129L1-1
Figure 3-18. Utility Menu Tree ........................................................................76
Figure 3-19. Test Menu Tree.............................................................................83
Figure 3-20. Pattern Results Display ..............................................................87
Figure 4-1. Example of Voice and Data Mix................................................91
Figure 4-2. First Two Configuration Menu Items.......................................95
Figure 4-3. First Two Network (NI) Configuration Menu Items .............96
Figure 4-4. First Two Network (NI) Menu Items .......................................97
Figure 4-5. DS0 Map A and Map B Configuration Menu Items...............98
Figure 4-6. Create Map Menu with Displayed DS0 Number ...................98
Figure 4-7. Display of DS0 Port Name.........................................................99
Figure 4-8. First Screen for Choosing to Review Temporary Files.........100
Figure 4-9. A Review Screen........................................................................100
Figure 4-10. Window Showing Edit Temp Option.....................................101
Figure 4-11. Window Showing the Error.....................................................102
Figure 4-12. Screen Verifying Interruption of Data Flow is OK ...............102
Figure 4-13. Window Showing Port Configuration Option......................103
Figure 4-14. Screen Used To Change Mode.................................................103
Figure 4-15. Test Menu One...........................................................................106
Figure 4-16. The Four Test Menu Windows ................................................107
Figure 4-17. Screen that Appears During Loopback Verification ............108
Figure 4-18. Test Pattern Screen for QRSS all DS0s....................................108
Figure 4-19. Window Displaying Test Pattern Results ..............................109
Figure A-1. TSU 120 Complete Menu Tree Diagram ................................ 112
Tables
Table 2-A. Network Pinout...........................................................................26
Table 2-B. Control In/Chain In Pinout.......................................................27
Table 2-C. Chain Out Pinout ........................................................................28
Table 2-D. V.35 Pinout - Nx56/64 DTE .......................................................29
Table 2-E. Pinout Connectors for Eight-Position
Modular Jack Interface ...............................................................30
Table 3-A. Normal Mode of Operation .......................................................74
Table 4-A. Configuration for Network Interface .......................................92
Table 4-B. Configuration for DTE Port .......................................................93
Table 4-C. Configuration for DS0 Map .......................................................94
Table 4-D. Configuration for DSX-1 PBX Passthru ...................................95
Table B-A. DTE Data Rate Vs. DS0s........................................................... 114
Table C-A. Control Pin Connection Configuration Chart for
Network Interface ..................................................................... 115
Table C-B. Configuration Chart for DTE Port .......................................... 116
Table C-C. DS0 Map A Configuration ....................................................... 117
Table C-D. DS0 Map B Configuration........................................................ 117

Chapter 1. Introduction
61200.129L1-1 TSU 120 User Manual 1
Chapter1
Introduction
TSU 120 OVERVIEW
A functional description of the T1 multiplexers, a
description of the TSU 120 rear panel, and a summary
of the features of the TSU 120 is provided in this
section. The unit is shown in Figure 1-1.
OK TEST ALARM OK TEST ALARM OK TEST ERROR ALARM
DSU/DSX MODULE CSU
3
2
1
6
5
4
9
8
7
#
0
*
C
B
A
F
E
D
CLEAR
ALARM
REMOTE
REMOTE
SHIFT
HOME
COPY
CANCEL
TSU120
ENTER
Figure 1-1
Front View of the TSU 120
Functional Description
The ADTRAN TSU 120 is one of several T1 multiplex-
ers that offers complete flexibility for connection of
various data sources to T1 or FT1 facilities. This
family of TSU multiplexers includes the TSU, TSU 100,
TSU 120, and the TSU 600.
TSU
The TSU is a T1 CSU/DSU with a single Nx56/64
serial port.

Chapter 1. Introduction
2TSU 120 User Manual 61200.129L1-1
TSU 100
The TSU 100 is the same as the TSU with the added
feature of a slot in the rear panel to house an option
module. Each module offers up to four additional
data ports.
TSU 120
The TSU 120 is the same as the TSU 100 with the addition of
a DSX-1 PBX interface to the base of the unit.
TSU 600
The TSU 600 is the same as the TSU with the added
feature of six slots in the rear panel to house up to six
option modules. Each module offers up to four
additional data ports for a total of 24 possible data
ports.
The TSU 120 serves as the link between user data
sources such as local area network (LAN) bridges and
routers, computers, CAD systems, teleconferencing
equipment, and PBXs. Through the use of multiple
data ports, the TSU 120 can simultaneously connect
one or more of these devices to a T1 circuit. The
amount of bandwidth allocated to each port is custom
programmable. The bandwidth allocation can be
changed manually or set to automatically change at
predetermined times to use the available bandwidth
most advantageously. Changes in the configuration
are accomplished without disrupting data flow in
channels that are not being re-configured. The unique
architecture and the availability of the option modules
provides a path for growth to accommodate future
requirements.

Chapter 1. Introduction
61200.129L1-1 TSU 120 User Manual 3
Identification of Rear Panel Layout
The configuration of the rear panel of the TSU 120 is
shown in Figure 1-2.
1. Option slot
2. Equipment Input Test Jack
3. Equipment Output Test Jack
4. Equipment Transmit Monitor Jack
5. DSX-1 Port Connection
6. V.35 Connection
7. Power Switch
8. Power Cord
9. Fuse Holder
10. Chain Out
11. Control/Chain In
12. Network Receive Monitor Jack
13. Network Output Test Jack
14. Network Input Test Jack
15. Network Connection
16. Loopback Test Connector
OPTION
SLOT 1
NETWORK IN OUT
CONTROL/
CHAIN PORT
NET
IN NET OUT RX MON
EQ
IN EQ OUT TR MON
.5A/250V
POWER
PORT 0.2 PORT 0.1
V.35
115VAC
60HZ
CAUTION:
FOR CONTINUED PROTECTION
AGAINST RISK OF FIRE,
REPLACE ONLY WITH SAME
TYPE AND RATNG OF FUSE.
DSX-1
1 2 3 4 5 6 7
15 14 13 12 11 10 9 8 16
Figure 1-2
TSU 120 Rear Panel
The items called out on the TSU 120 rear panel in
Figure 1-2 are defined in the following list:
Option Slot Receptacle for option cards
Equipment Input test jack for the terminal
Input Test Jack equipment
Equipment Output test jack for the terminal
Output Test Jack equipment
Equipment Monitor jack for the transmit
Transmit Monitor equipment output
Jack

Chapter 1. Introduction
4TSU 120 User Manual 61200.129L1-1
DSX-1 Port RJ-45 connector for the DSX-1
Connection port (terminal equipment)
V.35 Connection High-speed V.35 digital data
interface
Power Switch Used to turn power on or off
Power Cord Input of permanent power cord
Fuse Holder Placement of .5 A/250 V fuse
Chain Out Connect to other TSU for
control
Control/Chain In Control input
Network Receive Monitor test jack for the
Monitor Jack incoming T1
Network Output Output test jack for T1 interface
Test Jack
Network Input Input test jack for T1 interface
Test Jack
Network Used to connect to the T1 network
Connection
Loopback T1 loopback connector for
Test Connector troubleshooting T1 installations

Chapter 1. Introduction
61200.129L1-1 TSU 120 User Manual 5
Features of the TSU 120
The TSU 120 offers the following features:
• A DS1 network interface, a DSX-1 PBX interface, and
an Nx56/64 DTE serial interface port
• An inband communication channel requiring only 8
K of bandwidth from a single DS0
• A slot to house option modules with up to four
additional data ports including voice
• Allows mix of port types to meet the data interface
requirements
• Easy configuration capabilities using simple menus
displayed in a liquid crystal display (LCD) window
operated by a front panel keypad
• Two programmable configuration maps that define
the bandwidth allocation between data ports
• Data drop and insert, as well as full drop and insert
• Flash memory for software updates
• Timing is selectable from the network, from the
DSX-1 interface, from the Nx56/64 DTE port,
internally, or from a secondary interface
• QRSS; 511 test patterns
• Extensive self test and monitoring provides assur-
ance of proper operation
• Manageable by ADTRAN T-Watch or SNMP (with
ADVISOR)
• A terminal mode for configuration using a VT-100
type terminal

Chapter 1. Introduction
6TSU 120 User Manual 61200.129L1-1
Interfaces
The TSU 120 base unit is equipped with a slot in the
rear panel to house option modules which provide a
variety of additional data ports. See Figure 1-3.
The base unit is equipped with the following five
interfaces:
• Network DSI interface perAT&T 61402
• DSX-1 (PBX)
• Nx56/64 serial V.35 high-speed interface
• Control input (RS-232)/Chain port input
• Chain port output
The option modules which are designed to slide into
the rear panel option slot can have up to four inter-
faces. The following modules are currently available:
• DSX-1 (PBX)
• Nx56/64 - single or dual
• Voice (FXS/FXO/4E&M/4T0) - 2 channels/4
channels
• Office Channel Unit Data Port (OCU DP) - single or
dual
• Full drop and insert
• Dial backup
TSU 120
PC or Modem
Network Nx56/64
Up to 4
Control
Input Chain Output
NI TSU 120
Nx56/64
Chain
Input Chain Output
NI
Option Option
Up to 4
DSX-1 DSX-1
To PBX To PBX
Figure 1-3
TSU 120 Interfaces