Changes and enhancements to the product and to the information herein will be documented and issued as a new release.
A customer opinion card is provided at the front of this publication and your comments are appreciated. If the form has
been removed, address comments to AT&T Paradyne Corporation, T echnical Publications, 8545 126th Ave. N., P.O.
Box 2826, Largo, Florida, U.S.A. 34649-2826. AT&T Paradyne may use or distribute any of the information supplied, as
appropriate, without incurring any obligation whatsoever.
ACCULINK is a registered trademark of AT&T.
ACCUNET is a registered trademark of AT&T.
ANALYSIS is a trademark of AT&T.
COMSPHERE is a registered trademark of AT&T.
DATAPHONE is a registered trademark of AT&T.
Dataroute is a registered trademark of Bell Canada.
MCI is a registered trademark of MCI Communications Corporation.
Microsoft is a registered trademark of Microsoft Corporation.
US SPRINT is a registered trademark of US SPRINT Communications Company.
Windows is a trademark of Microsoft Corporation.
COPYRIGHT E 1995 AT&T Paradyne Corporation. All rights reserved.
This publication is protected by federal copyright law. No part of this publication may be copied or distributed, transmitted, transcribed, stored in a retrieval system,
or translated into any human or computer language in any form or by any means, electronic, mechanical, magnetic, manual or otherwise, or disclosed to third parties
without the express written permission of A T&T Paradyne Corporation, 8545 126th A venue North, P.O. Box 2826, Largo, Florida 34649-2826.
AT&T Paradyne Corporation makes no representation or warranties with respect to the contents hereof and specifically disclaims any implied warranties of
merchantability or fitness for a particular purpose. Further, AT&T Paradyne Corporation reserves the right to revise this publication and to make changes from
time to time in the contents hereof without obligation of AT&T Paradyne Corporation to notify any person of such revision or changes.
AFebruary 19953550-A2-GB20-10
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 three-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 three-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.
Safety Instructions
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.
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. T o 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.
Safety Instructions
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.
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.
This user’s guide provides the information needed to
install and operate your 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 1Provides 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 3Provides step-by-step instructions for
installing your carrier-mounted
Model 3551 DSU.
Chapter 4Describes how to operate your DSU
and its DBM and TDM/Flex options.
Chapter 5Presents 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 AProvides a diagram for navigating
the DSU’s menu structure.
Appendix BSummarizes the configuration option
sets for you.
Appendix CLists the DSU’s status indicators, as
well as their messages, identifying
when they appear.
Appendix DShows point-to-point and multipoint
application configurations and
network hookups.
Appendix EProvides cable and connector pin
assignments.
Appendix FEquipment List
Glossary
Reference Card
Chapter 2Provides step-by-step instructions for
installing your standalone
Model 3550 DSU.
vii3550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
Related Documents
Other product documentation includes the following:
The 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 56kbps
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 64kbps.
• 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
AT&T Paradyne’s COMSPHEREr6700 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.
1-13550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
• 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.
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.
• 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 SeriesNetwork Management System, User’s Guide. These are
identified in the Related Documents section of the
Preface, which also provides a telephone number you can
call to order these documents.
• 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.
1-2February 19953550-A2-GB20-10
About Your DSU
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-tosynchronous 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.
• 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 (T able 1-1)
• Specifications for the Model 3550 and 3551 DSU
only (T able 1-2)
• Specifications for the V.32 DBM (Table 1-3)
• 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.
• Specifications for the 2-port TDM/Flex
1-4
1-33550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
Table 1-1
(1 of 2)
General Technical Specifications
Specifications
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
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)
Criteria
Class A digital device
AW292J-61661-DD-N
Listed U L 1950, second edition
Recognized Component UL 1950, second edition
3 (0.029 amp, 4.5 watts at 1 15 Vac)
3 (0.080 amp, 8.0 watts at 1 15 Vac)
3 (1.650 amp, 165 watts at 1 15 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.
ENVIRONMENT
Operating Temperature
Storage Temperature
Relative Humidity
Shock and Vibration
EIA-232-D/CCITT V.24 (ISO 2110)
CCITT V.35 (ISO 2593)
EIA-232-D/CCITT V.24 (ISO 2110)
CCITT V.35 (ISO 2593)
(A V.35 Interconnect Cable is required to use the V.35 connector. The
cable provides an interface between the DSU’s 25-pin D-type connector
and the DTE cable’s V.35 connector.)
32° to 122° F (0° to 50° C)
–4° to 158° F (–20° to 70° C)
5%—95% (noncondensing)
Withstands normal shipping and handling
1-4February 19953550-A2-GB20-10
SpecificationsCriteria
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)
About Your DSU
Table 1-1
(2 of 2)
General Technical Specifications
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 RATESAsync or Sync rates: 64, 56, 48, 19.2, 14.4, 12.0, 9.6, 4.8, 2.4, and
NMS COMPATIBILITY
1.2 kbps
Other asynchronous rates (e.g., 150, 300, 600, and 1800 bps) can be
obtained through oversampling
Asynchronous rates support CCITT V.14 extended rate range at
8 to 12 bits per character, including the
percent overspeed/underspeed compensation at 10 bits per character)
COMSPHEREr 6700 Series NMS, Release 4.0 or greater
start
and
stop
bit (+2.3, –2.5
1-53550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
Table 1-2
DSU Technical Specifications
SpecificationsCriteria
APPLICATIONFull- or half-duplex data transmission via point-to-point or multipoint
DDS network, or local area data channel
COMMUNICATION LINELeased 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.
Compatibility Bulletin CB-INC-101, and
Pacific Bell publications
PUB L-780035-PB/NB and
PUB L-780036-PB/NB
DSU COMPATIBILITY
Primary Channel
Requires 3600 Series Hubbing Device which provides
two 8-pin modular jacks
Via the SDU in the COMSPHEREr 3000 Series Carrier
2.4, 4.8, 9.6, and 56 kbps
19.2 kbps loop at levels of +6, 0, or –10 dBm
All A T&T Paradyne digital products and other products that are
compliant with A T&T Technical Reference 62310 – 1987
1-6February 19953550-A2-GB20-10
About Your DSU
Table 1-3
V.32 DBM Technical Specifications
SpecificationsCriteria
RINGER EQUIVALENCE NUMBER (REN)DBM option 0.7B
APPLICATIONFull- or half-duplex data transmission via analog 2-wire dial network,
point-to-point
MODULATION AND FREQUENCYAt 14.4 and 12 kbps: CCITT V.32bis, 1800 Hz
At 4.8 and 9.6 kbps: CCITT V.32, 1800 Hz
At 2.4 kbps: CCITT V.22bis, 2400 Hz
COMMUNICATION LINE2-wire analog (PSTN) line
DATA RATES2.4, 4.8, 9.6, 12, 14.4 kbps
DBM COMPATIBILITYIf Call Setup is set for Callback or Password security, then the device is
compatible with a Model 3550 or 3551 V.32 DBM.
any
V.32 modem can be
APPROVALS
DOC
Certification (PSTN)
Load Number
RECEIVE VF INTERFACE
Dynamic Range
V.32 2-wire PSTN
Impedance
SWITCHED NETWORK INTERFACE
3550 DSU
If Call Setup is set for Alarm or None, then
used.
Also, V.22bis at 2.4 kbps can be used.
230 3684 A
7
–43 to –10 dBm
600 Ω
6-pin modular jack
Permissive: USOC RJ11C
8-pin modular jack
Programmable: USOC RJ45S
3551 DSU
TRANSMIT VF INTERFACE
Signal Level
V.32 2-wire Dial (PSTN)
Impedance
(One or two) 50-pin connector
Permissive: USOC RJ21X
Programmable: USOC RJ27X
Permissive: –9 dBm
Programmable: –12 to 0 dBm (set by a resistor in the telco jack)
600 Ω
1-73550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
Table 1-4
2-Port TDM/Flex Technical Specifications
SpecificationsCriteria
APPLICATION
Multiplexing
Digital sharing
PORT SYNCHRONOUS RATES1.2, 2.4, 4.8, 9.6, 12.0, 14.4, 19.2, 48, 56, and 64 kbps
PORT ASYNCHRONOUS RATES150, 300, 600, 1200, and 1800 bps plus all primary (DSU) rates.
PORT DTE INTERFACE
3550 DSU (2-port TDM/Flex)
NMS SUPPORTTDM/Flex capability is fully supported by Release 4.0 or greater
Provides time division multiplexing of two independent ports.
Allows consecutive ports to share the same TDM/Flex channel.
Asynchronous rates support +2.3, –2.5 percent overspeed/
underspeed compensation.
Provides an additional 25-pin D-subminiature connector for a total of two
EIA-232 or V.35 interfaces.
COMSPHERE 6700 Series NMS.
Equipment Warranty
and Support
AT&T Paradyne’s Customer Assistance Center is
available 24 hours a day to help you place an installation
request, report a hardware or software problem, or place a
trouble report. The center provides technical support and
remotely diagnoses equipment problems Monday through
Friday, between the hours of 8 a.m. and 8 p.m. EST,
excluding holidays. You can also call the center if you
participate in the on-site support program (refer to the
Enhanced Support Services section) or if you would like
to request support on a time and materials basis.
Call the following toll-free number to reach the
Customer Assistance Center:
1-800-237-0016
NOTE
Effective January 1, 1995, the
Customer Assistance Center is
available to provide technical
support 24 hours a day, 365 days
a year.
Equipment Service
To obtain service under your warranty, call the
Customer Assistance Center at the number listed above.
Please have the following information available before
you call:
Company Name and Address
Contact Name and T elephone Number
Shipping Address, if different from the company
address
Billing Address, if different than the shipping
address
Model Number and Serial Number of the unit
A brief description of the problem
The Customer Assistance Center will verify that the
equipment is in need of repair. You are provided a Return
Materials Authorization (RMA) number to help expedite
the repair request. Once you receive an RMA number,
pack the unit securely and ship the package insured andpostage prepaid to:
AT&T Paradyne Corporation
Customer Support
Attn: Repair Center
8550 Ulmerton Road, Building B
Largo, Florida 34641
Make sure the RMA number is in a visible location on
the outside of the package.
1-8February 19953550-A2-GB20-10
About Your DSU
Out of Warranty
If your equipment is out of warranty and you do not
have a maintenance support agreement, factory repair
support is available.
To send equipment to AT&T Paradyne’s Repair Center,
call the following toll-free number Monday through
Friday, between the hours of 8 a.m. and 5 p.m. EST,
excluding holidays:
1-800-772-7691
Please have your purchase order number and the
information listed in the Equipment Service section ready
when you call for your RMA number. Package and ship
the equipment to the Repair Center as described, making
sure the RMA number is clearly visible on the outside of
the package.
Enhanced Support Services
In addition to the customer support described, AT&T
Paradyne offers a wide variety of enhanced customer
support programs that are designed to meet our customers
needs. Our high quality support programs range from
equipment installation to premium on-site support, as well
as network management.
For more information about our enhanced support
services, contact your AT&T Paradyne representative, or
call the following toll-free number, 8 a.m. to 5 p.m. EST,
excluding holidays:
The Model 3550 DSU is designed for desktop
operation and is delivered ready to connect to the
network. It is configured as a tributary DSU for operation
at 9.6 kbps on a multipoint circuit.
If the unit was ordered with a TDM/Flex installed,
Ports 1 and 2 are configured for 9.6 kbps operation, and
configured as a digital sharing device (DSD). Both ports
are configured for EIA-232 operation, rather than V.35
operation. Refer to the MUX (Port) option set tables in
Chapter 5 to change this configuration on a port-by-port
basis.
Installation consists of the following steps, which
should be performed in the order listed.
• Physical installation
• Hardware straps
• Electrical connection
• Network diagnostic connection
• Software configuration
• DDS network (or LADS) connection
• Dial (or PSTN) network connection if a DBM is
installed, or if using an external dial backup unit
(DBU)
• DSU DTE connection
• V erification testing
Although the Model 3550 DSU is designed for desk or
table-top operation, you can order an ACCULINKr
3100 Series CSU wall-mount adapter if you want to
mount the DSU on a wall, an equipment shelf, a 19-inch
RS-310-C or 23-inch AT&T DATAPHONEr equipment
cabinet. Refer to Appendix F to order the adapter.
Before You Begin
Your installation site should be clean, well-lighted,
well-ventilated, and free from environmental extremes.
A dedicated grounded ac outlet that is protected by a
circuit breaker should be installed within 6 feet of the
DSU’s planned location. The outlet should be capable of
supplying 90 to 132 Vac 60 Hz (U.S. and Canada). The
2-13550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
circuit must be capable of supplying a minimum of
2 amperes at 115 Vac. Refer to the TechnicalSpecifications section in Chapter 1 for additional power
requirements.
CAUTION
The ac transformer contains a
3-wire grounding-type plug which
has a grounding pin. This is a
safety feature. Do not defeat the
purpose of the grounding plug by
modifying it or by using an
adapter.
Prior to installation, use an outlet
tester to check the ac receptacle
for earth ground. If the power
source does not provide a ground
connection, consult an electrician
to determine another method of
grounding the DSU before
proceeding with the installation.
Before connecting the DSU, you need to contact the
telephone company to coordinate your installation before
connecting the DSU to their network. The DSU can only
be operated at the data rate for which access to the DDS
network is provided. If a DBM is installed, the DSU must
also be connected to the dial network. You must notify the
telephone company before you connect to the dial
network. Refer to the notice at the front of this guide to
ensure compliance with FCC, Bell Canada, and Canadian
DOC rules.
No on-site assembly of the DSU is required. However,
installation should not proceed if any of the following is
missing:
• A power cord with table-top ac transformer
• A 14-ft cable for connection to the DDS network,
with 8-pin RJ48S modular plug on each end
For Canadian purchasers, an 8-pin RJ48S connector is
on one end while a 6-pin connector is on the other is
required (order feature number 3000-F1-006).
If the DSU is equipped with a DBM, a dial interface
cable should have been ordered.
• Permissive (RJ11C) – a 6-pin modular plug at each
end (feature number 4400-F1-53x or 3600-F3-503).
• Programmable (RJ45S) – an 8-pin modular plug at
each end (feature number 4400-F1-54x).
Contact your AT&T Paradyne representative if any of
these items is missing from the shipping container, or to
order the appropriate dial interface cable.
If your DSU is equipped with a DBM, you may need to
change the DSU’s hardware straps before installing the
DSU.
How to Change
Hardware Straps
HANDLING PRECAUTIONS
FOR
ST ATIC SENSITIVE DEVICES
AT&T Paradyne products are
designed to protect sensitive
components from damage due to
electrostatic discharge (ESD) during
normal operation. When
performing installation procedures,
however, take proper static control
precautions to prevent damage to
equipment. If you are not sure of the
proper static control precautions,
contact the nearest AT&T Paradyne
Customer Support office.
The Model 3550 DSU has a switch located behind its
diagnostic control panel (DCP). This switch contains two
straps, one that controls the permissive or programmable
connection when a DBM is installed, and one that controls
the frame-to-signal grounds. T able 2-1 shows the DSU’s
settings. Refer to Figure 2-1 and the following steps if you
need to change one of these straps.
.
Procedure
1. With your thumbs under the edge of the front
bezel, firmly press upward to lift the bezel from
the tabs securing it in place.
2. Swing the front bezel up and set the bezel aside.
3. Refer to Table 2-1 to determine which switch
needs to be changed. Then, using a small
instrument, carefully change the position of the
switch.
4. Reinsert the front bezel’s hinge tabs into position
and swing the bezel down. Snap the bezel back
into place.
2-2February 19953550-A2-GB20-10
Installing the Model 3550 DSU
S11
Figure 2-1. Model 3550 Hardware Switch Location (shown without a TDM/Flex)
Table 2-1
Model 3550 DSU Switch Settings
Switch PositionSwitch SettingFunction
ON
S1-1
S1-2
ON is to the rear as you face the front of the DSU.
Off is to the front.
(default)
OffProgrammable V.32 DBM transmit level between –12 dBm and 0 dBm
ONFrame ground (FG) connected to signal ground (SG)
Off
(default)
Permissive V.32 DBM transmit output level of –9 dBm
FG connected to SG through 100 ohm resistor
2-33550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
Where to Place the DSU
As mentioned earlier, the DSU must be placed within
6 feet of a dedicated grounded ac outlet that is protected
by a circuit breaker.
The distance between the DSU and its DTE must be
within EIA-232-D/V.24 limits, or V.35 limits if operating
the DSU at speeds greater than 19.2 kbps.
• For the EIA-232 connector, the typical maximum
distance is 50 feet at speeds less than or equal to
19.2 kbps. If a longer distance is needed, use high
quality , low capacitance cable and ensure that the
effective shunt capacitance of the circuit (measured
at the DSU and including the capacitance of the
cable and the DTE) does not exceed 2500
picofarads, as specified in EIA-232-D.
• For the V.35 connector, the maximum distance
recommended between the DSU and the DTE is
nominally 1000 feet.
Allow 1 to 2 feet of clearance around the DSU for
access and cable connections during installation.
Installing the DSU
Before installing the DSU, label the circuit breaker that
protects the ac wall outlet, and make sure that it is set to
ON. Then, proceed with the installation.
.
Procedure
1. Place the DSU in its planned location. Make sure
the ventilation slots are not blocked.
2. At the rear of the DSU (Figure 2-2), insert the ac
transformer, circular plug into the interface labeled
POWER.
3. Plug the ac transformer’s 3-prong plug into the ac
wall outlet.
CAUTION
Only use the power
transformer designed for the
Model 3550 DSU. Using other
transformers may result in
personal injury or damage to
the equipment.
Figure 2-2. Model 3550 Electrical Connection
2-4February 19953550-A2-GB20-10
Installing the Model 3550 DSU
Power-Up Routine
When power is applied, the DSU:
• Determines what options (DBM or TDM/Flex) are
installed, if any.
• Runs a Device Test on itself and each of the
installed options.
During the tests, all indicators on the DCP light
briefly and the message Power-Up Tests appears on
the liquid crystal display (LCD).
• Displays the results of each test momentarily as
Pass, Fail, or Abrt. (Abrt indicates that the Device
Test was aborted because a network loopback was
in progress during the power-up procedure.) These
tests take about 20 seconds to complete.
If a TDM/Flex is installed, MUX is displayed as
Pass or Fail.
If the DSU, DBM, or TDM/Flex (MUX) fails this test,
follow these steps. Refer to Appendix A as you perform
the procedures described in this guide. Refer to Chapters 4
and 5 for additional examples and procedures.
6. Press the
configurations into view, and select the
appropriate configuration.
• PTPC for a point-to-point control
• PTPT for a point-to-point tributary
• MPTC for a multipoint control
• MPTT for a multipoint tributary
7. Press the F1 key to SAVE the selected
configuration.
The Save to screen appears.
8. Save the selected configuration to Activ
(F1 key).
9. Press the
then select Local again.
10. Select Test (F3).
The Run Test on screen appears.
11. Select the device that Failed: the DSU (or the
TDM/Flex) or DBM.
key to bring the factory-loaded unit
key to return to the top-level menu,
.
Procedure
1. Press the
2. Select Local (F1 key).
3. Press the
(Configuration) branch into view.
4. Press the function key directly below Confg.
5. Press the F1 key to select Opts (Configuration
Options).
The Load from screen appears.
key to return to the top-level menu.
key to scroll the Confg
12. Press the F2 key to run the Device Test again.
The device should pass.
13. Should the device fail, return the unit to the
AT&T Paradyne Repair Center (see Chapter 1).
Connecting to the Network
The DSU provides three interfaces (often called a
jack). One jack connects the DSU to the 6700 Series
NMS, one connects the DSU to the dial (or public
switched telephone network – PSTN) network, and one
connects the DSU to the DDS network. Follow the
appropriate procedure when making your network
connections.
2-53550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
Connecting to the NMS
A 3600 Hubbing Device is required to connect the
control DSU to the 6700 Series NMS. When connected to
the NMS, the DSU can be controlled and configured from
the NMS rather than from the DCP alone.
.
Procedure
1. Plug the 4-pin modular plug of the 3600 Hubbing
Device (Figure 2-3) into the DSU jack labeled
CC/DC.
2. Plug one end of an M6BJ cable into the hubbing
device jack labeled CC IN/DC OUT.
3. Plug the other end of the 8-pin M6BJ cable into
the 8-pin end of the 873A adapter.
4. Plug the D-type end of the 873A adapter into the
appropriate 6700 Series NMS jack.
Refer to your COMSPHERE 6700 Series NMS
documentation to control and configure the DSU from the
NMS.
Connecting to the Dial (or PSTN) Network
If your DSU is equipped with a V.32 DBM, refer to
Figure 2-4 as you follow these steps.
.
Procedure
1. Plug either end of the dial (analog) interface cable
into the DSU jack labeled BACKUP.
• Permissive service – telephone cord with 6-pin
modular RJ11C plug
• Programmable service – telephone cord with
8-pin RJ45S plug
2. Plug the other end of the cable into the modular
jack provided by the telephone company, USOC
RJ11C (permissive) or USOC RJ45S
(programmable).
3. If your site has programmable service, verify that
the DSU’s hardware strap S1-1 is switched to the
OFF position.
Figure 2-4. Model 3550 DSU
Figure 2-3. Model 3550 DSU NMS Connection
2-6February 19953550-A2-GB20-10
Dial (PSTN) Network Connection
Installing the Model 3550 DSU
Connecting to the DDS (or LADS) Network
NOTE
Before connecting the DSU to the
DDS network, ensure that approved
primary protectors have been
installed on the circuit in accordance
with Article 800 of the National
Electric Code, NFPA 70, in the United
States and Section 60 of the
Canadian Electric Code, Part 1, in
Canada.
Refer to Figure 2-5 as you follow these steps.
.
Procedure
1. Plug the DDS network interface cable into the
DSU jack labeled LINE.
• U.S. – select either end of the cable
• Canada – select the 8-pin end
2. Plug the other end of the cable into the modular
jack (USOC RJ48S) provided by the circuit
provider.
If connecting the DSU to a LADS network, there are
distance limitations that govern the use of DSUs on the
network. T able 2-2 summarizes these limitations.
Figure 2-5. Model 3550 DSU DDS (LADS)
Network Connection
If the remote DSU is also connected to the network, the
DSU’s green OK indicator lights and the Alrm indicator
goes off. The Health and Status screen no longer displays
a No Signal message.
2-73550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
Data Rate
Table 2-2
LADS Connection Distances
Data Rate
(kbps)
2.420.0 mi
(32.2 km)
4.819.4 mi
(31.2 km)
9.615.2 mi
(24.5 km)
1
19.2
38.41 1.2 mi
569.2 mi
649.2 mi
1
Power level is –10 dBm.
1 1.8 mi
(19.0 km)
(18.0 km)
(14.8 km)
(14.8 km)
Wire Gauge (AWG)
19222426
16.6 mi
(26.7 km)
12.7 mi
(20.5 km)
9.7 mi
(15.6 km)
7.5 mi
(12.1 km)
6.5 mi
(10.5 km)
5.4 mi
(8.7 km)
5.4 mi
(8.7 km)
12.7 mi
(20.5 km)
9.6 mi
(15.4 km)
7.3 mi
(11.7 km)
5.7 mi
(9.2 km)
4.6 mi
(7.4 km)
3.8 mi
6.2 km)
3.8 mi
(6.2 km)
9.4 mi
(15.1 km)
7.1 mi
(11.5 km)
5.6 mi
(9.0 km)
4.2 mi
(6.8 km)
3.2 mi
(5.1 km)
2.8 mi
(4.5 km)
2.8 mi
4.5 km)
Addressing the Unit
A unique address must be assigned to each control and
tributary DSU in your network. You can assign an address
within the range of 1 through 255.
NOTE
Do not assign the number 192 as a
network address. This number is
reserved as a broadcast address.
If a DBM is installed, it requires a separate address
which is automatically assigned by the DSU. The address
assigned a DBM is the DSU’s address, plus 1 (e.g., if the
DSU’s address is 1, the assigned DBM address will be 2).
NOTE
The numbers 191 and 255 cannot be
assigned to a DSU that has a DBM.
However, addresses can be assigned
in any order; they do not have to be
sequential.
It is recommended that only
numbered
to DSUs so that
addresses
addresses be assigned
even-numbered
are reserved for DBMs.
odd-
If your network does not currently
include DBMs, you retain the
flexibility to add them later without
having to reconfigure your entire
network.
2-8February 19953550-A2-GB20-10
Installing the Model 3550 DSU
Tributary DSU Addressing
Tributary DSU addresses are user-definable, but take
care that their addresses are unique on a multipoint circuit.
If two tributaries are assigned the same address, you will
not be able to communicate with either one.
The control DSU accesses its tributary by specifying
the tributary’s address.
The 6700 Series NMS accesses the DSU via its
network address. To access a tributary DSU, the NMS
first addresses the control, then the tributary. An address
issued from the NMS takes the format of control
channel/control network address/tributary network
address. This is called link-level network addressing.
Figure 2-6 shows an example of DSU and DBM
addressing, as well as link-level network addressing.
Refer to Chapter 4 to learn how to set the DSU’s
network address.
Figure 2-6. Addressing Example
2-93550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
Connecting the DSU to a DTE
The DSU’s rear panel has both a 25-pin EIA-232-D/
V.24 connector and a 34-pin CCITT V .35 connector (used
for higher operating speeds). You can use either interface.
When the unit is equipped with a TDM/Flex, either of
these interfaces can be used as Port 1. The TDM/Flex
provides an additional interface to be used as Port 2. This
is a D-type connector. If the port is to operate at a speed
greater than 19.2 kbps, use the V.35 interconnect cable to
provide an interface between the TDM/Flex’s D-type
connector and the DTE cable’s V.35 connector.
Figure 2-7 shows a DSU as well as a DSU equipped
with a TDM/Flex. The DSU without TDM/Flex illustrates
cabling for an EIA-232 application; the DSU with
TDM/Flex illustrates cabling for V.35 applications. Refer
to this figure as you connect your DSU to the data
terminal equipment (DTE). Be sure to select the
appropriate cable, EIA-232 or V.35, for your application.
.
Procedure
1. Connect the plug end of the DTE cable to Port 1,
either the EIA-232-D or the V.35 connector.
(Figure 2-7 shows Port 1 using the EIA-232-D
connector.)
Tighten the two holding screws.
2. Connect the other end of the cable to the
appropriate port on the computer or DTE.
Tighten any holding screws.
3. If necessary, activate the port to match the
interface, either EIA-232 or V.35 (the default
setting is EIA-232).
Figure 2-7. Installing Cables
2-10February 19953550-A2-GB20-10
Installing the Model 3550 DSU
Connecting Port 2
For the EIA-232 cable, install as described above.
For the V.35 cable, install the V.35 Interconnect Cable,
then the V.35 DTE cable as follows (refer to Figure 2-7).
.
Procedure
1. Reconfigure the port to match the interface, V.35
in this example.
2. Connect the 25-pin plug end of the V.35
Interconnect Cable (feature number 3000-F1-510)
to Port 2.
Tighten the holding screws.
3. Connect the plug end of the 34-pin V.35 DTE
cable to the other end of the V.35 Interconnect
Cable.
Tighten the holding screws.
4. Connect the other end of the DTE cable to the
appropriate port on the computer or DTE.
Tighten the holding screws.
Refer to Chapter 4 to learn how to reconfigure the
DSU’s port(s).
3. Select Stat (Status branch).
4. Press the
5. Select ID.
6. Press the
7. Verify that the correct address has been entered.
Repeat this procedure for each tributary DSU in the
network.
key until ID appears.
key until Network Addr appears.
Verifying the Network
Perform a Digital T est on the DDS circuit to ensure
that the network is functioning.
.
Procedure
1. Select Test (F3).
2. Select DSU (F1).
3. Press the
4. Select DT.
5. Select Start (F1).
6. Select a port.
key until DT appears.
Verifying Operation and
Testing Connections
Verification testing should be performed after any
installation.
After installing and configuring the circuit (including
control and tributary DSUs, the DDS network, the DBMs
and their dial connections), perform the following series
of tests from the control DSU to verify network operation
(using either the DCP or NMS).
Verifying Network Addresses
Access the DSU’ s identity (ID) subbranch for each
tributary DSU to ensure that the DSUs are properly
addressed. Refer to Chapter 5 for an example using the
DCP, if needed.
.
Procedure
1. Select Remot (Remote branch).
2. Enter the tributary’s network address.
7. Enter the address of the remote DSU.
8. Select the amount of time you want the test to run
in hours: minutes: seconds (hh:mm:ss).
• Press the
cursor to the digit to be changed.
• Press the F1 (") key to increment the digit
(1 through 9).
• Press the F2 (↓) key to decrement the digit.
9. Select Enter (F3). Please wait appears as the DSU
starts the test.
10. When Command Complete appears, press the
key.
11. Select Displ (F1) to display the results of the test.
Table 4-6 in Chapter 4 shows the information
received from a Digital T est.
12. Press the
or key to move the blinking
key to scroll through each result.
2-113550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
Verifying DBM Operation
If a DBM is installed, test the tributary DBM for
dial tone, and verify that the DSU can place and receive
calls.
.
Procedure
1. Select Bckup (F2).
2. Select Dial to establish a dialed call to the
tributary.
(Refer to Chapter 4 for the procedure for entering
telephone numbers.)
3. Select !Dial to switch to the dial circuit.
4. Perform a Digital Test following the DBM path
rather than the DSU path.
(No error message should appear.)
5. Select DrBU to drop the backup call.
6. Perform a Digital Test on the DBM. Follow the
Verifying the Network procedure, selecting DBM
instead of DSU (Step 2).
Other Tests
The following lists the tests available on your DSU.
Refer to the Test Branch section of Chapter 4 for further
test information, as well as more detail on how to
configure and operate the DSU. Refer to Appendix A to
determine how best to access each test.
• Device Test (Devic)
• Local Loopback (LL)
• DTE Loopback (DTE)
• Digital Loopback (DL)
• Remote Digital Loopback (RL)
• Bilateral Loopback
• Digital Test (DT)
• End-to-End Test (EE)
• Bit Error Rate Test (BERT)
• Lamp Test (Lamp)
Verifying TDM/Flex Operation
If a TDM/Flex is installed, perform a Digital T est on
A Model 3551 DSU is designed for installation in a
COMSPHERE 3000 Series Carrier, which supplies power
and provides the interfaces for connecting to the DDS or
dial networks. Up to 16 DSUs can be installed in the
carrier. Refer to the COMSPHERE 3000 Series Carrier,Installation Manual for additional carrier and installation
information.
The DSU is delivered ready to install in the carrier. It is
configured as a control DSU for operation at 9.6 kbps on a
multipoint circuit.
A rear connector plate, which is installed onto the rear
of the carrier, is shipped with the DSU. The rear connector
plate contains two connectors: a 25-pin EIA-232-D/V.24
connector and a 25-pin V.35 connector. Once installed, the
DSU can be removed from the front of the carrier without
disconnecting the DTE cables.
Installation of the DSUs and carrier-related equipment
consists of the following steps, which should be
performed in the order listed.
• Hardware straps
• DSU physical installation
• Network diagnostic connection
• Software configuration
• DDS network (or LADs) connection
• Dial (or PSTN) network connection
(if a DBM is installed)
• DSU DTE connection
• V erification testing
3-13550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
Before You Begin
The COMSPHERE 3000 Series Carrier should already
be installed properly and be operational, with a
functioning shared diagnostic control panel (SDCP). An
SDCP (installed in the carrier) is required for installation
and maintenance of the Model 3551 DSU. For installation
information, see the COMSPHERE 3000 Series Carrier,Installation Manual.
A fan module may also be needed to dissipate heat.
Refer to the Fan Module Installation section in Chapter 3
of the COMSPHERE 3000 Series Carrier, InstallationManual to determine whether a fan is required.
The distance between your DTE and the DSU must be
within EIA-232-D/V.24 or V.35 limits.
• For the EIA-232 connector, the typical maximum
distance is 50 feet at speeds less than or equal to
19.2 kbps. If a longer distance is needed, use high
quality , low capacitance cable and ensure that the
effective shunt capacitance of the circuit (measured
at the DSU and including the capacitance of the
cable and the DTE) does not exceed 2500
picofarads, as specified in EIA-232-D.
• For the V.35 connector, the recommended
maximum distance between a DTE and DSU is
nominally 1000 feet.
Before connecting the DSU, you need to contact the
telephone company to coordinate your installation before
connecting the DSU to their network. The DSU can only
be operated at the data rate for which access to the DDS
network is provided. If a DBM is installed, the DSU must
also be connected to the dial network. You must notify the
telephone company before you connect to the dial
network. Refer to the notice at the front of this guide to
ensure compliance with FCC, Bell Canada, and Canadian
DOC rules.
How to Change
Hardware Straps
HANDLING PRECAUTIONS
FOR
ST ATIC SENSITIVE DEVICES
AT&T Paradyne products are
designed to protect sensitive
components from damage due to
electrostatic discharge (ESD)
during normal operation. When
performing installation
procedures, however, take
proper static control precautions
to prevent damage to
equipment. If you are not sure of
the proper static control
precautions, contact the nearest
A T&T Paradyne Customer
Support office.
The Model 3551 DSU has several hardware straps that
control the permissive or programmable connection when
a DBM is installed, the T est Mode Indication leads, and
the external interface leads (used with a –48 Vdc Central
Office Power Unit).
Refer to Figure 3-1 to locate the switch and jumper
locations. If a DBM is installed, refer to T able 3-1 to
determine which switch needs to be changed, if any. Refer
to Table 3-2 to determine whether these jumper straps
need to be changed.
3-2February 19953550-A2-GB20-10
Installing the Model 3551 DSU
S1-1
Figure 3-1. Model 3551 DSU Switch and Jumper Locations
Model 3551 DSU Switch Settings
Switch Position
S1-2
ON is to the rear as you face the front of the DSU.
Off is to the front.
Switch SettingFunction
ON
(default)
OffProgrammable V.32 DBM transmit level between –12 dBm and
ONFrame ground (FG) connected to signal ground (SG)
Off
(default)
Table 3-1
Permissive V.32 DBM transmit output level of –9 dBm
0 dBm
FG connected to SG through 100 ohm resistor
3-33550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
Strap
Designation
J12LeftV.35 T est Mode Indication:
J13LeftEIA-232-D Test Mode Indication:
J20LeftAlarm Monitoring (used with the –48 Vdc Central Office Power Unit):
State of
Jumper Strap
Table 3-2
Model 3551 DSU Jumper Straps
Left
— Enables V.35 Test Mode Indication (Pins 1 and 2).
factory default.
Right
— Disables V.35 Test Mode Indication (Pins 2 and 3).
Left
— Enables EIA-232-D Test Mode Indication
(Pins 1 and 2).
Right
— Disables EIA-232-D Test Mode Indication
(Pins 2 and 3).
Left
— Disables the –48 Vdc alarm monitoring function
(Pins 1 and 2).
Right
— Enables the –48 Vdc alarm monitoring function
(Pins 2 and 3); the NMS adapter cable is being used for alarm
monitoring.
This is the factory default.
This is the factory default.
Function
This is the
J21RightAlarm Monitoring (used with the –48 Vdc Central Office Power Unit):
Left
— Enables control of alarm monitoring via the NMS adapter
cable (Pins 1 and 2); the NMS adapter cable is being used for alarm
monitoring.
Right
— Disables control of alarm monitoring via the NMS adapter
cable (Pins 2 and 3); a standard EIA-232 cable or the NMS adapter
cable is being used for the diagnostic channel.
This is the factory
default.
3-4February 19953550-A2-GB20-10
Installing the DSU
The initial installation procedure for the Model 3551
DSU requires the installation of a rear connector plate
onto the rear of the COMSPHERE 3000 Series Carrier
(Figure 3-2). After the initial installation, the DSU can be
installed or de-installed by simply removing the DSU
from the carrier.
Installing the Model 3551 DSU
.
Procedure
1. At the rear of the carrier, set the tab on the rear
connector plate into one of the slotted grooves on
the carrier’s backplane. Loosely fasten the screws.
Make sure the rear connector plate uses the same
slot position intended for the DSU.
2. Loosely fasten the screw attached to the rear
connector plate, allowing for slight adjustment
that may be needed when installing the DSU.
3. Change any default hardware strap settings that
may be required before installing the DSU.
Figure 3-2. COMSPHERE 3000 Series Carrier, Rear V iew
3-53550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
4. Using a Phillips screwdriver, loosen the screw
holding the circuit pack lock and rotate the lock to
the open position (Figure 3-3). Open the latch.
5. At the front of the carrier, hold the DSU vertically
with the latch on its faceplate in the open position.
Then, insert the circuit card into the top and
bottom circuit card guides for the slot that
contains the rear connector plate.
Slide the DSU into the slot, aligning the circuit
card with the rear connector plate until the
connectors seat firmly into the back of the carrier.
Press the faceplate latch to secure the DSU into
the carrier, rotate the circuit pack lock into the
closed position (Figure 3-3), and tighten the screw.
6. Return to the rear of the carrier and tighten the
rear connector plate screw.
Figure 3-3. Model 3551 DSU Installation and Circuit Pack Lock
3-6February 19953550-A2-GB20-10
Installing the Model 3551 DSU
7. At the rear of the carrier, connect the appropriate
DTE interface cable (EIA-232-D or V.35) to the
rear connector plate. For an EIA-232-D interface
cable, connect the EIA-232-D cable to the top
DTE connector on the rear connector plate.
For the 25-pin V.35 interface, a V.35 interconnect
cable is shipped with the unit. T o connect a V.35
interface cable to the 25-pin V.35 connector, refer
to Figure 3-4 and perform the following steps:
a. Connect the 25-pin end of the DSU’s V.35
Interconnect Cable to the bottom DTE
connector of the rear connector plate. Tighten
the screws on each side of the connector.
b. Connect the 34-pin end of the DSU’s V.35
Interconnect Cable to the V.35 interface cable,
then tighten the screws on each side of this
connector.
8. The installed DSU is connected to the DDS
network through the 50-pin connectors at the rear
of the carrier. These interfaces are specified in the
USOC RJ48T, and the pin assignments are shown
in Appendix D. Proper network connection to the
DDS facility or to the network channelterminating equipment must be made at the far
end of the cable.
9. If the network line and remote DSU are installed
and tested, do a Remote Loopback – a T est Pattern
test.
10. If the Front Panel test switch strap is to be
disabled, slide the DSU slightly out of the carrier,
open switch S3-1, then reseat the DSU into the
carrier. Do this now.
11. Circuit ID information can be written on the cover
plate under the appropriate slot number.
Figure 3-4. V.35 Interconnect Cable Installation
3-73550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
Power-Up Routine
When power is applied, the DSU:
• Determines what options (DBM or TDM/Flex) are
installed, if any.
• Runs a Device Test on itself and each of the
installed options.
During the tests, all indicators on the DCP light
briefly and the message Power-Up Tests appears on
the liquid crystal display (LCD).
• Displays the results of each test momentarily as
Pass, Fail, or Abrt. (Abrt indicates that the Device
Test was aborted because a network loopback was
in progress during the power-up procedure.) These
tests take about 20 seconds to complete.
If a TDM/Flex is installed, MUX is displayed as
Pass or Fail.
If the DSU or DBM fails this test, follow the procedure
below . Refer to Appendix A as you perform the
procedures described in this guide. Refer to Chapters 4
and 5 for additional examples and procedures.
.
Procedure
1. Press the
key to return to the top-level menu.
7. Press the F1 key to SAVE the selected
configuration.
The Save to screen appears.
8. Save the selected configuration to Activ
(F1 key).
9. Press the
then select Local again.
10. Select the Test branch (F3).
The Run Test on screen appears.
11. Select the device that Failed: the DSU (or the
TDM/Flex) or DBM.
12. Press the F2 key to run the Device Test again.
The device should pass.
13. Should the device fail, return the unit to the
AT&T Paradyne Repair Center (see Chapter 1).
key to return to the top-level menu,
Connecting to the Network
Network connections are provided through the
3000 Series Carrier. Refer to Figure 3-2 as you read the
following sections and set up your network connections.
2. Select Local (F1 key).
3. Press the
(Configuration) branch into view.
4. Press the function key directly below Confg.
5. Press the F1 key to select Opts (Configuration
Options).
The Load from screen appears.
6. Press the
configurations into view, and select the
appropriate configuration.
• PTPC for a point-to-point control
• PTPT for a point-to-point tributary
• MPTC for a multipoint control
• MPTT for a multipoint tributary
key to scroll the Confg
key to bring the factory-loaded unit
Connecting to the NMS
A Model 3551 DSU is set up for network diagnostic
connection through the shared diagnostic unit (SDU),
which is installed in Slot 0 of the carrier. Refer to the
COMSPHERE 3000 Series Carrier, Installation Manual
to set up the network diagnostic connection.
For connection of the DSU, see Appendix E of this
guide. For pin assignments, see Appendix D.
Connecting to the
Dial (or PSTN) Network
Connection to the dial network (or public switched
telephone network – PSTN) for the carrier-mounted
Model 3551 DSU is through a network interface module
(NIM) that is installed onto the carrier’s backplane (see
Figure 3-2). Refer to the COMSPHERE 3000 SeriesCarrier, Installation Manual for additional information or
to install the NIM.
3-8February 19953550-A2-GB20-10
Installing the Model 3551 DSU
Connecting to the
DDS (or LADS) Network
NOTE
Before connecting the DSU to the
DDS network, ensure that approved
primary protectors have been
installed on the circuit in accordance
with Article 800 of the National
Electric Code, NFPA 70, in the
United States and Section 60 of the
Canadian Electric Code, Part 1, in
Canada.
If connecting the DSU to a LADS network there are
distance limitations that govern the use of DSUs on the
network. T able 2-2 in Chapter 2 summarizes these
limitations.
The DDS network interface is provided by two RJ48T
50-pin connectors on the back of the carrier (refer back to
Figure 3-2, DDS Interface). Each connector serves eight
contiguous slots in the carrier: one for Slots 1 through 8
and one for Slots 9 through 16.
Appendix E provides connectivity diagrams should you
need further assistance in connecting the DSU to the
network.
Each DSU can be configured to use either interface
(EIA-232 or V.35) independent of other DSUs in the
carrier. Connection of the DSU to the DTE is a matter of
selecting and installing the appropriate cable. Refer to the
COMSPHERE 3000 Series Carrier, Installation Manual
for installation procedures.
Appendix E provides connectivity diagrams should you
need further assistance in connecting the DSU to the
network.
Addressing the Unit
A unique address must be assigned to each control and
tributary DSU in your network. You can assign an address
within the range of 1 through 255.
NOTE
Do not assign the number 192 as a
network address. This number is
reserved as a broadcast address.
If a DBM is installed, it requires a separate address
which is automatically assigned by the DSU. The address
assigned a DBM is the DSU’s address, plus 1 (e.g., if the
DSU’s address is 1, the assigned DBM address will be 2).
Connecting the DSU to a DTE
The DTE interface for the Model 3551 DSU is
provided through its rear connector plate. Each rear
connector plate contains two DB25 (or 25-pin D-type)
connectors. The top connector is an EIA-232-D/V.24
(ISO 2110) connector. The bottom connector is a CCITT
V.35 (ISO 2593) connector.
To use the 25-pin V.35 connector (used for speeds
greater than 19.2 kbps), a V.35 interconnect cable is
needed (feature number 3000-F1-510). This cable
provides the interface between the 25-pin V.35 D-type
connector and a V.35 DTE cable.
NOTE
The numbers 191 and 255 cannot be
assigned to a DSU that has a DBM.
However, addresses can be assigned
in any order; they do not have to be
sequential.
It is recommended that only
numbered addresses
to DSUs so that
addresses
If your network does not currently
include DBMs, you retain the
flexibility to add them later without
having to reconfigure your entire
network.
even-numbered
are reserved for DBMs
odd-
be assigned
.
3-93550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
Tributary DSU Addressing
Tributary DSU addresses are user-definable, but take
care to ensure that their addresses are unique on a
multipoint circuit. If two tributaries are assigned the same
address, you will not be able to communicate with either
one.
The control DSU accesses its tributary by specifying
the tributary’s address.
The 6700 Series NMS accesses the DSU via its
network address. To access a tributary DSU, the NMS
first addresses the control, then the tributary. An address
issued from the NMS takes the format of control
channel/control network address/tributary network
address. This is called link-level network addressing.
Figure 3-5 shows an example of DSU and DBM
addressing, as well as link-level network addressing.
Refer to Chapter 4 to learn how to set the DSU’s
network address.
Verifying Operation and
Testing Connections
Verification testing should be performed after any
installation.
After installing and configuring the circuit (including
control and tributary DSUs, the DDS network, the DBMs
and their dial connections), perform a series of tests fromthe control DSU to verify network operation (using either
the SDCP or NMS).
Figure 3-5. Addressing Example
3-10February 19953550-A2-GB20-10
Installing the Model 3551 DSU
To Connect the SDCP to a DSU
For the carrier-mounted Model 3551 DSU, the SDCP
must first be reconnected to the DSU. Once connected, the
SDCP operates like a DCP.
.
Procedure
1. Press the Select key (refer to Figure 3-2).
A screen similar to the following appears.
Carr:Slot: 1: 01 A
1:02A
F1F2
The cursor is usually positioned under the second
position of the slot number (1:01
In this example, the first line shows
1 indicates Carrier 1 (Carr)
01 indicates the DSU in Slot 1
F3
).
2. Press the Select key on the SDCP again.
The SDCP accesses the DSU in Carrier 1, Slot 1.
The top-level menu (your starting point) of the
carrier-mounted DSU is displayed.
1:01A DSU 9.6 C
Local Remot
F1
F2
F3
From the first line of this example, you can see
that this is a carrier-mounted DSU (1:01A instead
of Port1) that is located in Carrier 1, Slot 1, is
operating as a DSU (i.e., not as a DBM), at
9.6 kbps, and is configured as a control (C).
From the second line you can see that there are no
NMS messages (no Msg branch over the F3 key)
waiting to be read and cleared.
Also note that the SDCP indicator on the selected
DSU’s faceplate, Front Panel, is lit.
A is reserved for future use
On the second line
Press the F1 key (↑) to increment the number
that the cursor is on.
Press the F2 key (↓) to decrement the number.
Press the
and keys to move the cursor
one position to the left or right, to change
either the carrier or slot number.
Press the F3 key to toggle between DSUs, to
switch from 1:01A to 1:02A in this example.
(In our example, the previously accessed DSU
was located in Slot 2 of Carrier 1.)
Verifying Network Addresses, the Network,
and DBM Operation
Access the DSU’ s identity (ID) subbranch for each
tributary DSU to ensure that the DSUs are properly
addressed.
Perform a Digital T est on the DDS circuit to ensure
that the network is functioning.
If a DBM is installed, perform the Digital Test by
selecting DBM from the Run Test from screen instead of
DSU. Next, test the tributary DBM for dial tone, and
verify that the DSU can place and receive calls.
Refer to the Verifying Operation and TestingConnections section of Chapter 2 for procedures that lead
you through each of these procedures.
3-113550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
Other Tests
The following lists the tests available on your DSU.
Refer to the Test Branch section of Chapter 4 for further
test information, as well as more detail on how to
configure and operate the DSU. Refer to Appendix A to
determine how best to access each test.
A 3550 Series DSU can be managed from its control
panel or from the COMSPHEREr 6700 Series NMS. This
chapter describes how to manage the DSU using the
control panel. Refer to the COMSPHERE 6700 SeriesData Network Management System, User’s Guide to
understand how to manage the unit from the NMS.
The DSU’s menus are organized as a branching
hierarchy , sometimes referred to as a menu tree. Refer to
Appendix A as you perform the procedures described in
this guide to help you quickly learn more about your
DSU.
DCP and SDCP Operation
There are two types of control panels, one for each
DSU model. The standalone Model 3550 DSU
(Figure 4-1), is controlled from its diagnostic control
panel (DCP); the carrier-mounted (nest- or rack-mounted)
Model 3551 DSU (Figure 4-2) is controlled from a shared
diagnostic control panel (SDCP). The SDCP is mounted
onto the COMSPHEREr 3000 Series Carrier to control
multiple units.
NOTE
Throughout this guide, DCP refers to
either control panel,
except where a distinction is made.
DCP
or
SDCP
,
Figure 4-1. Model 3550 Diagnostic Control Panel
4-2February 19953550-A2-GB20-10
Operating the DSU
Figure 4-2. SDCP and Model 3551 DSU Faceplate
Both control panels have a 2-line, 16-character liquid
crystal display (LCD) and a keypad, through which you
can
• Monitor the unit’s health and status
• Initiate dial backup
• Initiate diagnostic tests
• Load or change the unit’s configuration, or how it
will operate
• Enable or disable the DSU’s, DBM’s, or port’s
transmitter
• Display or change the status of the general purpose
external DTE leads.
The DCP’s LCD displays the result of any command
initiated from the DCP.
Refer to Appendix C to understand the meaning of
DCP status indicators.
Keypad
There are seven keys on the DCP of the standalone
Model 3550, and eight on the SDCP for the carriermounted Model 3551 DSU. The additional key, the Select
key, connects the SDCP to a specific DSU located in a
specific carrier and slot within the carrier.
4-33550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
F1F2
• The key returns you to the top-level menu, and
terminates any work in progress.
F3
Status Branch
The Status (Stat) branch reports on the health and
status of the DSU, DBM, TDM/Flex, the DTE interface,
the quality of the dial connection, the identity of the DSU
(model number, serial number, etc.), and the terminal’s
power (where it checks the presence of voltage on the
DTE’s RTS lead).
• The
one level up from the current display. It can also be
used to terminate a data entry display without
making a change.
• The
displays to the left or right, respectively.
On status and test result displays, the
keys scroll additional information into view.
On data entry displays, these keys move the cursor
one character to the left or right to allow entry of
one digit or character at a time.
• Function keys (F1, F2, or F3) select the item
displayed directly above the key.
Additional information on operating the DSU’s keypad
can be found in the procedures used to install and verify
operation of the DSU in Chapters 2 and 3, the procedure
for editing configuration options in Chapter 5, and the
various procedures scattered throughout this chapter.
key returns you to the previous display,
and keys scroll menus or other
and
Menu Structure
The menu is your map through the DSU’s various
functions. The following sections describe each branch
and subbranch, and provide procedures for operating
certain features. Appendix A shows the complete menu
and describes the DSU’s branches and subbranches. ( The
menu is also included on the handy Reference Card that
comes with this guide.)
Health and Status
The Health and Status (H/S) subbranch displays the
health and status of the DSU, as well as a DBM or
TDM/Flex, if installed. It automatically scans for DSU
and line conditions that are not within normal limits.
There are three types of Health and Status messages:
• Devic (Device Health and Status)
• Expan (Expanded Health and Status)
• Subn (Subnetwork Health and Status)
All alarm and status conditions are displayed for the
specified DSU at the time the option is selected. For alocal DSU, the alarm and status conditions are updated
every 2 seconds; for a remote DSU, the alarm and status
conditions are not updated.
Refer to Appendix C for a complete listing of these
messages.
Device Health and Status
Device Health and Status (Devic) reports health and
status information for a selected DSU. If five minuteselapse without a key being pressed, the Device Health and
Status screen is redisplayed.
• When the digital circuit is the active link,
— The first line displays a running
normal-operation timer (hh:mm:ss).
— The second line displays the DSU’s operating
Top-Level Menu
The top-level menu is the starting point for all DSU
operations. You can always return to this point from
anywhere in the menu by pressing the
this key immediately terminates any operation or work in
progress. Refer to Appendix A as you read about the
branches and subbranches.
4-4February 19953550-A2-GB20-10
key. Pressing
rate and can also display one or more of the test
or alarm messages.
• An asterisk ( * ) appears at the far right to indicate
NMS activity.
• A right arrow (→) appears just before the asterisk
if there is more than one message. Press the
key to see the next message.
Operating the DSU
Expanded Health and Status
Expanded Health and Status (Expan) only appears
during automatic dialing. It retrieves Health and Status
information for the local DSU after an automatic backup
attempt has failed, or when there is a disconnect after a
successful connection.
If the right arrow (→) appears to the right of ExpandedH/S, there is more than one message. Press the
see the next message.
key to
Subnetwork Health and Status
Subnetwork Health and Status (Subn) displays status
information from a DSU’s subnetwork (all DSUs and
DBMs assigned to that DSU’s active poll list). The
downstream network addresses and current statuses are
listed. T o page through tributary addresses:
• Press the F1 key (↑) for the next highest network
address.
• Press the F2 key (↓) for the next lowest network
address.
Circuit Quality
Circuit Quality (CircQ) shows the level and quality of
the signal being received from the network by the DBM.
This subbranch is only available for a V.32 DBM.
Identity
Identity (ID) displays a listing of the DSU’s model and
serial numbers, the equipment installed (DBM or
TDM/Flex), software/firmware versions, the network
address, the DDS or DSU’s rate, the DBM’s rate, and
whether the TDM/Flex is currently activated.
.
Procedure
1. Press the
2. Press the function key (F1, F2, or F3) directly
below the selection. One field at a time is
displayed.
3. Press the
display (screen) at a time.
Table 4-1 lists the Identity information provided about
the DSU and its equipment.
key to scroll ID into view.
key to display the information, one
DTE Status
The DTE status subbranch provides a snapshot status
of the local or remote unit’s external DTE interface.
• For the local DSU status, the display is sampled
and updated every 2 seconds.
• For the remote DSU status, only one set of states is
returned based upon a monitoring period of
approximately 3 seconds.
The DTE interface statuses are displayed in sets. Use
or key to scroll each set of lead statuses into
the
view.
Terminal Power
Terminal Power (TPwr) displays the status of the
connected DTE’s EIA-232 and V.35 interface (connector).
The DSU checks the state of the RTS lead to determine
when the DTE is ON.
• When the voltage is less than –3V or greater than
+3V for both the EIA-232 and V.35 interfaces,
— The second line displays On if power is
detected.
— The second line displays Off if no power is
detected.
4-53550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
Table 4-1
Identity Descriptions
Description
Model:3550 or 3551.
S#:Unit serial number.
DSU SW ver:Software/firmware version residing on DSU.
Netwrk Addr:Unit’s network address.
DSU Rate:Value set for DSU
DBM Rate:Value set for DBM
appears when a V.32 DBM is installed.
MUX Card:2Prt – Type of TDM/Flex installed. It only appears when a TDM/Flex is installed.
MUX App:TDM or None – Currently configured application (refer to the
only appears when a TDM/Flex is installed.
MUX SW ver:Software/firmware version residing on TDM/Flex. It only appears when a TDM/Flex is
installed.
Rate(Kbps)
Rate(Kbps)
Backup Branch
The Backup (Bckup) branch controls dial backup
operation. This branch appears when a DBM is installed,
or when the DSU is configured to support an external dial
backup unit (DBU). The following sections explain dial
Information Displayed
configuration option.
configuration option; the DBM’s aggregate speed. It only
MUX (Setup)
option set). It
DBM Option Set:
• AutoAnswer – Select Enab.
When enabled, this option set allows the DBM to
answer an incoming call. (Enab is the
factory-loaded default setting.)
backup operation.
• Call Setup – Set call setup security level:
Dial Backup Operation
The Model 3550 or 3551 DSU with dial backup
capability can provide backup for a point-to-point circuit
operating at 14.4 kbps or below. Appendix E shows some
typical dial backup system configurations.
Backup is controlled primarily by software
configuration options in the DBM or ExtBU, and Backup
option sets. The unit can be configured so that backup can
be either automatic or manual. Backup can be controlled
from either the DSU’s control panel or a 6700 Series
NMS.
Backup begins with configuring the unit.
Configuring the Unit for Dial Backup
The following configuration options should be set,
whether initiating backup manually or automatically.
None – No call setup security is required.
(None is the default.)
Password – Originating and receiving DBMs
exchange passwords before the DBMs can
enter Standby mode. There must be an
incoming password (RxPwd) and an outgoing
password (TxPwd) set up.
Callback – Both DBMs must exchange
passwords and a Backup Directory pointer
must be sent before a call can be initiated.
There must be an incoming password (RxPwd)
and an outgoing password (TxPwd) set up, and
the originator’s local telephone number (Phone
subbranch) must be stored in the answering
DBM’s Backup Directory.
Alarm – No security is to be used at the
control DBM, and the DBM only answers
incoming calls when there is a facility alarm.
If the control DSU is to initiate the call, set the
control for Pswrd and the tributary for Cllbk.
4-6February 19953550-A2-GB20-10
Operating the DSU
If the tributary DSU is to initiate the call, set the
control for Cllbk and the tributary for Pswrd.
External DBU Option Set (This option set will
not appear if a DBM is installed.):
• ExtBU – Select whether the external DBU will
answer or place backup calls. The external DBU
must be able to support Dial on DTR.
Ansr – The external DBU will answer
incoming calls. The DBU must provide DSR
when the call is complete.
Orig – The external DBU will place an
outgoing call.
None – The external backup feature is
disabled. The DSU will not switch data to the
alternate port. (None is the default.)
Backup Option Set (None of these need to be set
for manual backup.):
• Auto Bckup – Select Enab.
When enabled, the DSU will automatically initiate
dial backup. Up to 10 attempts will be made.
If both the control and tributary DSUs are
configured for automatic backup, NtwkTimOut
should be set to different values so that the control
and tributary DSUs do not try to place a call at the
same time.
On a point-to-point circuit, it is best that only one
end performs automatic backup. It is possible to
trigger the backup for single-direction network
failures only detected at the remote DSU. The
remote DSU must have RTS Control set to FrcOn.
• Bckup Dir – Select the call directory identifier
(1 to 10) stored in the DBM’s Backup Directory for
the telephone number to be dialed.
• AutoRestor – Select Enab.
When enabled, the DBM or external DBU
automatically restores data to the DDS circuit when
service is restored and the amount of time set in
RestoreTimOut has expired.
• NtwkTimOut – Set the amount of time that the
DDS circuit must be out of service before a backup
attempt is made: from 0:00 (minutes:seconds) to
29:59 (the default is 0:20).
• TriesTimeOut – Specify the overall time limit
during which a DBM will automatically attempt to
establish a dial backup call: from 1 to 60 minutes
(the default is 15 minutes). Auto Bckup must be
enabled.
• MultiCall – Select Enab.
When enabled, instead of following the normal
calling cycle, the DBM cycles through all dial
strings contained in its Backup Directory until a call
attempt is successful.
Do not enable MultiCall unless more than one
telephone number is in the Backup Directory and
each successive (i.e., 1, 2, 3, etc.) telephone number
is different from the previous entry. Directory
entries should be unique.
Understanding Operating Modes
When a DSU is equipped with a DBM or an external
DBU, the Backup branch controls operation of the Dial
Backup function. The DBM has four modes of operation:
• In Idle mode, there is no dialed connection. The
DDS circuit is active and carrying user data and
diagnostics.
• In Standby mode, the unit has a dialed connection
to another DBM or compatible dial backup unit, but
the DDS circuit is still active and carrying user
data. The dialed digital circuit carries diagnostic
traffic addressed to either the tributary DSU or
DBM. These diagnostics do not disrupt the DDS
circuit.
• In Dial Backup mode, the dialed circuit is active
and carrying user data and diagnostics.
• In External Backup mode, the external DBU is
the DSU’s alternate connection with the remote
device. Depending upon how the DSU is
configured, the external DBU will either establish
the dialed connection (ExtBU set to Orig) or
respond to an incoming call (ExtBU set to Ansr).
Once the dialed connection is established, the DSU
switches data and diagnostics to the dialed link,
then drops backup when service is restored.
Table 4-2 lists the Backup branch operating modes and
explains the effects of each backup command.
• RestorTimOut – Set the amount of time that the
DDS circuit must be back in service before
automatic restoration is attempted: from 1 to
60 minutes (the default is 5 minutes).
4-73550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
Table 4-2
Backup Branch Menu Selections
Current
Backup Mode
IdleBkup
StandbyDisc
Dial BackupDrBU
External BackupExtBUIf
Backup
Command
Dial out, establish, and switch to dialed link (Dial Backup mode).
Dial
→Dial
→DDS
DrBUDisconnect dialed link and switch to private line (Dial Backup mode).
Dial out and establish dialed link (Standby mode). (Data is routed over the DDS
circuit.)
Disconnect dialed link (Idle mode).
Switch data to dialed link (Dial Backup mode).
Disconnect dialed link and switch to private line (Idle mode).
Switch data to DDS (Standby mode).
ExtBU
mode). Select this command to establish a backup call. When the backup call is
established, the DSU switches data to the dialed link.
Manual Backup
You can control each step of a backup attempt by
following one of these procedures.
Effect
in the ExtBU option set is set to Orig, this command is displayed (Idle
5. Select Dial (F2); the DBM places the call.
6. Once the dialed call has been established, select
!
Dial to switch data to the dial path.
Placing a Backup Call
To place a backup call:
.
Procedure
1. Go to the Bkup option set under the Confg branch
and set Auto Bckup to Disab.
2. Select Bckup (Backup branch) to select a
telephone number from the Backup Directory.
If the telephone number in the Backup Directory is
the number you want to dial, go to Step 5.
3. Select Dial, the Backup Dir screen is displayed
identifying the Backup Directory indicator.
4. Select another telephone number to call:
• Press the F1 key (↑) to increment the directory
indicator (e.g., 1 to 2).
• Press the F2 key (↓) to decrement the indicator
(e.g., 2 to 1).
Manual DDS Restoration
Data can be switched back to the DDS circuit once
DDS service has been restored.
.
Procedure
1. From the Bckup branch, select !DDS to restore
data traffic to the DDS circuit.
2. If the DDS circuit operates normally after the
switch, select DrBU to drop the backup circuit.
3. If the DDS circuit fails to perform reliably, select
!
Dial again to quickly route data back over the
dialed connection.
Manual Dial Backup Termination
• If in Standby mode, select Disc.
• If in Dial Backup mode, select DrBU.
• If in External Backup mode, select DrBU.
4-8February 19953550-A2-GB20-10
Operating the DSU
Test Branch
The Test branch provides extensive testing capabilities
for the DSU, the DDS circuit, the DBM (if installed), and
the backup circuit. When the tributary DSU receives a test
request from the control DSU, it aborts any locally
initiated test in progress.
Running a test can affect your application data or may
cause your application session to be dropped depending
upon front-end processor, time-out parameters, etc. since
no data or acknowledgment messages will be transmitted
while the test is in progress.
Abort
The Abort selection allows you to abort a test that is
running. The DSU cannot run any other test until the test
in progress is aborted.
There are two types of selections to abort a test:
• Selective terminates whatever test is in progress at
the local DSU.
• Subn (Subnetwork) only displays at the control
DSU. This selection terminates any test running at
the control DSU or at a tributary DSU or DBM
associated with the control.
After selecting either Selective or Subn, the test is
terminated and the DCP displays the message CommandComplete.
Device Test
The Device (Devic) Test uses a test pattern generator
built into the DSU. If a DBM is installed, the DBM must
be in Idle mode, with no call in progress if you want to run
a Device Test.
NOTE
On power-up, the DSU sends out
polls to determine whether a DBM is
installed. It then initiates a Device
Test on itself and the DBM. The
results of the tests appear
momentarily on the DCP’s LCD.
Loopback
The Loopback (Lpbk) branch displays four loopbacks:
• Local Loopback (LL)
• DTE Loopback (DTE)
• Digital Loopback (DL)
• Remote Digital Loopback (RL)
Figure 4-3 shows where each loopback occurs on the
circuit. Refer to the figure as you read about loopbacks.
Local Loopback
Local Loopback (LL) is session-disruptive; that is,
performing the test will disrupt data. It permits the DTE to
run a test to determine whether the DTE connection to the
DSU and the DSU itself are functioning properly. The
DSU must be connected to the DTE, but the network
connection to the DSU is not required. This test cannot be
performed by the DBM.
While the DSU is in Local Loopback, any data
transmission by the DTE is returned as received data. An
operator can send a test pattern and verify correct
reception of the test. The DSU does not monitor this
testing.
Figure 4-3. Loopbacks
4-93550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
NOTE
To issue a Local Loopback to a
tributary DSU
DBM installed or a
message will appear. The DBM is
required to call the tributary and abort
the Local Loopback.
If the NMS is to abort the loopback,
the tributary’s DBM must be in Idle or
Standby mode. If in Dial Backup
mode and the NMS issues the
command, the command will not be
recognized. The loopback will have to
be aborted from the DSU’s control
panel.
, the DSU must have a
Conflict w/ Environ
Abort
DTE Loopback
DTE Loopback (DTE) loops back the data path at the
DTE interface on a per-port basis without affecting the
operation of the remaining ports. This loopback is used to
verify that the DTE connection and the cable are good.
point-to-point or multipoint network, whereas a tributary
DSU can originate Remote Digital Loopback in a
point-to-point network only.
When a DSU (control or tributary) originates Remote
Digital Loopback, both the originating DSU and the
targeted DSU enter Test mode. No other test can be run at
the originating DSU or the targeted DSU until the Remote
Digital Loopback is aborted.
The DSU does not generate test results.
Bilateral Loopback
Bilateral Loopback (Bilat Lpbk) is a combination of
DTE and Digital Loopbacks operating simultaneously in
the same DSU. Both Bilateral and Digital Loopbacks are
selected from the General (Gen) option set.
NOTE
If
Bilat Lpbk
Remote Digital Loopback or Digital
Test will automatically initiate a DTE
Loopback, as well.
is enabled, requesting a
Digital Loopback
Digital Loopback (DL) allows manual testing of the
remote end of the circuit. Data coming in is immediately
transmitted back. For example, a Digital Loopback may
be required in order to complete an external bit error rate
test (BERT) from the remote DSU. The local DSU
receives test data, loops it back to the transmitter before
the DTE interface, and returns it to the network.
Digital Loopback can also be initiated by receiving a
V.54 pattern to go into Digital Loopback. Enable
configuration options V.54 Lpbk (V.54 Loopback) andRespondRDL (Respond to Remote Digital Loopback).
Remote Digital Loopback
Remote Digital Loopback (RL), sometimes referred to
as RDL, typically supports testing using an external
device, like a protocol analyzer that is connected to the
local DSU’s DTE interface. A test message from the
external device is looped back from the receiver to the
transmitter in the remote DSU and returned to the local
DSU.
In Remote Digital Loopback, the local DSU (control or
tributary) puts the remote DSU into Digital Loopback. A
control DSU can originate Remote Digital Loopback in a
Digital Test
The Digital T est (DT) checks the functionality of a pair
of DSUs and the data circuit between them. This test can
also be run on a DBM over a backup connection to a
remote DBM for point-to-point testing.
The remote DSU is placed in Digital Loopback, then
the local DSU transmits the 511-bit test pattern over the
network to the remote DSU for an operator-specified
length of time. In a multipoint network (where only a
control DSU can originate a Digital T est), tributary DSUs
not involved in the test are placed in T est mode for the
duration of the test.
During the test, the TXD, RXD, and RTS LED
indicators show the states of the leads at the DTE
interface. At the conclusion of the test, the local DSU
releases the remote DSU from Digital Loopback.
To review the results of the test, select Displ (Display)
and press the
in Table 4-3.
When the test is over, the top line displays Final
instead of Active.
key to scroll through the results shown
4-10February 19953550-A2-GB20-10
Operating the DSU
Table 4-3
Digital Test Results
Results
Time:Running test timer. (The Clr
Tot Error:Running count of bits in error;
Err Secs:Running count of errored
Run on:port
nn
Information Displayed
selection resets the timer to
0:00:00.)
Max, if the maximum error
count has been reached, the
maximum being 64000. (The
Clr selection resets the counter
to 0.)
seconds. (The Clr selection
resets the counter to 0.)
If this test was not run on an
aggregate data path, the Digital
Test was run on port
nn
.
End-to-End Test
The End-to-End (EE) T est is used to analyze a control
and a tributary DSU or DBM, and the network circuit
between them in both directions independently. It
transmits fixed packets (or blocks) of data between DSUs
or DBMs When an End-to-End T est is run, diagnostic data
may be disrupted.
To view the results of the test, select Displ (Display)
and press the
key to scroll through the results shown
in Table 4-4.
When the test is over, the top line displays Final
instead of Active.
Bit Error Rate Test
The Bit Error Rate T est (BERT) is a session-
disruptive test that transmits a 511-bit pattern. It analyzes
the network circuit. It can monitor the results by putting
the remote DSU or DBM into Digital Loopback and
checking the returned pattern for errors, or by
simultaneously executing a BERT in the local DSU.
The test continues until aborted from the DCP or NMS.
This test can be run on a per-port basis if a TDM/Flex is
installed. A control DSU can initiate a Bit Error Rate Test
in a point-to-point or a multipoint network. A tributaryDSU can only initiate this test in a point-to-point network.
If nondisruptive diagnostics are in effect (if Diag Type
is set to NonD), diagnostic data can be disrupted.
To display the results of the test, press F2 to select
Displ. The results are shown in Table 4-5. T o clear the
results of the test and clear the counters to zero, press F3
to select Clr.
Table 4-4
End-to-End Test Results
Results
Time:Local and
Tot Block:Local and remote
Rx Blk err:Local and remote
Tx Blk err:Local and remote
Rx TimOuts:Local DSU/DBM onlyNumber of blocks that were not received or acknowledged by the
1
Local
refers to the test initiator.
Reported By
Remote DSU/DBM
DSU/DBM
DSU/DBM
DSU/DBM
1
Running test timer. (The Clr selection resets the timer to 0:00:00.)
Number of blocks completed. (The Clr selection resets the counter to 0.)
Number of incoming blocks with errors detected, indicating a fault in the
incoming transmission path. (The Clr selection resets the counter to 0.)
Number of blocks with errors detected at the remote DSU, indicating a
fault in the outgoing transmission path. (The Clr selection resets the
counter to 0.)
remote DSU or DBM. (The Clr selection resets the counter to 0.)
Information Displayed
4-113550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
Table 4-5
Bit Error Rate Test Results
ResultsInformation Displayed
Time:Running test timer. (The Clr
selection resets the timer to
0:00:00.)
Tot Error:Running count of bits in
error; Max, if the maximum error
count has been reached, which
is 64000. (The Clr selection
resets the counter to 0.)
Err Secs:Running count of errored
seconds. Errored second is at
least one error is detected during
a 1-second time period. (The Clr
selection resets the counter to
0.)
Run on:port
nn
Port selected for testing.
Lamp Test
The Lamp Test is a test of the status indicators (LEDs)
and liquid crystal display (LCD) on the DSU’s control
panel (both models). Any indicator that does not flash is
not functional.
Note that if all LEDs are functioning, all the indicators
on the Model 3550 DCP are flashing steadily. In a
COMSPHERE 3000 Series Carrier, the indicators on the
SDCP remain ON. The LCD on the DCP or SDCP
alternately flashes solid blocks, moving from position to
position on the display until the test is aborted.
Pressing any key except the
portion of the Lamp T est and return you to the DSU Test
menu so you can abort the test. Once aborted, the LCD
and LEDs stop flashing.
key will stop the LCD
Configuration Branch
The Configuration (Confg) branch allows you to
configure or customize the DSU and its equipment (DBM
or TDM/Flex) to fit your site’s requirements, to enter and
change telephone numbers (if a DBM is installed), and to
specify the mode for viewing or editing configuration
options.
The 3550 Series DSUs have two special features that
simplify configuration of your DSU: Menu mode and the
preset (factory-set) unit configurations to fit typical DSU
applications.
It is recommended that you set the Menu mode before
you select an application configuration, or access option
sets.
Selecting Menu Mode
By selecting Menu from the Configuration Options
(Opts) branch, you can
• View and configure options in each option set, or
• View and edit only those options that are more
likely to change.
This feature saves time and simplifies customization of
your DSU’s configuration. Appendix B, ConfigurationWorksheets, summarizes the unit’s configuration options
for each Menu mode selection.
.
Procedure
1. Select Local (F1) for the local DSU.
2. Press the
branch) is displayed.
3. Select the function key directly below Opts (F3).
4. Press the
key until Confg (Configuration
key to display Menu.
5. Select Menu (F1). Full Mode appears on the first
line of the LCD.
4-12February 19953550-A2-GB20-10
Operating the DSU
6. Select the mode:
• Enable Full Mode (F2) – All configuration
options will be displayed.
• Disable Full Mode (F3) – Only those
configuration options likely to change will be
displayed.
When the selection is made, it is displayed on the
first line of the LCD (e.g., Full Mode: Disab).
7. Select Save (F1).
8. Press the
submenu.
9. Select Opts (F2) and view the difference in the
configuration options displayed based upon the
current Menu mode.
key to return to the Configure
Selecting an Application Configuration
The DSU is shipped from the factory with four
common applications already configured. All you have to
do is select the appropriate application and load the preset
configuration into the unit. These configurations include:
NOTE
By referencing the menu in
Appendix A, you will see that
pressing the key is more
efficient if the unit is to operate
on a multipoint circuit.
4. Make your selection: PTPC, PTPT, MPTC, or
MPTT, and press the function key (F1, F2, or F3)
directly below the desired configuration.
The Edit/Save screen appears.
To view the point-to-point or multipoint configuration
loaded:
.
Procedure
1. Select an option set (e.g., DSU – F2 key).
2. Press the F1 key (Next) to scroll through each
configuration option’s default (factory-loaded)
setting.
• PTPC – Point-to-point control DSU.
• PTPT – Point-to-point tributary DSU.
• MPTC – Multipoint control DSU.
• MPTT – Multipoint tributary DSU.
Select the appropriate configuration based upon how
the unit will be used within your network. (Examples of
typical point-to-point and multipoint configurations are
shown in Appendix E. Refer to the DSU’s menu in
Appendix A as you follow these steps.
.
Procedure
1. Select Confg (Configuration branch).
2. Press the F1 key to select Opts (Configuration
Options subbranch).
The Load from screen appears.
3. Press the
configuration into view.
or key to scroll the desired
NOTE
If
Full Mode
was
enabled
option will display.
If
Full Mode
configuration options likely to
change will display.
The option sets (DSU, Diag, DBM, etc.) scroll
from the last to the first (e.g., MUX!PrtSp
SAVE!DSU!Diag etc.).
3. Select Prev (press the
then select it).
4. Press the
screen.
You can select another option set to view, or you
can proceed.
Refer to Chapter 5, Configuring the Unit, for an
example showing you how to edit (change)
configuration options.
(Menu subbranch)
, every configuration
was
disabled
key to return to the Edit/Save
, only
key to display Prev,
!
4-133550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
5. Select Save (F1).
The Save to screen appears.
6. Select Activ (F1).
The selected application’s configuration is saved
to the DSU’s Active operating area, and the
Command Complete message appears.
Configuration Options
The Configuration Options (Opts) subbranch allows
you to save, copy, and/or change configuration options. It
also is the place where the DSU’s ports are configured (or
reconfigured) for EIA-232 or V.35 operation.
Refer to Chapter 5, Configuring the Unit. Chapter 5
fully explains the Opts subbranch, and provides an
example of changing configuration options.
Reconfiguring a DSU Port
Select this procedure if your unit does not have a
TDM/Flex installed and enabled.
.
Procedure
1. Select the Confg (Configuration branch).
2. Press the F1 key to select Opts (Configuration
Options subbranch).
3. Select Activ (Active), or one of the factory-set
configurations (PTPC, PTPT, MPTC, or MPTT)
from the Load from screen.
4. Press the
above a function key (F1, F2, or F3).
5. Select Gen. (The first configuration option in the
option set is DTE Port.)
6. Select V.35 (the default is EIA232).
The DTE Port setting changes to V.35.
7. Press the
key until Gen (General) appears
key to return to the Edit/Save menu.
Reconfiguring a TDM/Flex Port
The Connecting the DSU to a DTE section of
Chapter 2 tells you how to connect Port 2 if your DSU is
equipped with a TDM/Flex.
With the TDM/Flex option, you can configure each
port (Port 1 or Port 2) independently (e.g., one port can be
configured for EIA-232 operation while other port is
configured for V.35 operation – or vice versa).
The unit is shipped with both ports configured for
EIA-232 operation.
To reconfigure a TDM/Flex port:
.
Procedure
1. Select the Confg (Configuration branch).
2. Press the F1 key to select Opts (Configuration
Options subbranch).
3. Select Activ (Active), or one of the factory-set
configurations (PTPC, PTPT, MPTC, or MPTT)
from the Load from screen.
4. Press the
function key.
5. Select MUX (F1).
If the TDM/Flex is disabled, go to the next step.
If the TDM/Flex is enabled, go to step 9.
6. Select Setup (F1).
7. For MUX Funct, select Enab.
8. Press the
Opts menu.
9. Select Prt1 (F3). (The first configuration option in
the option set is DTE Port.)
10. Select V.35 (the default is EIA232).
The DTE Port setting changes to V.35.
11. Press the
Opts menu.
key until MUX appears above a
key to return to the Change MUX
key to return to the Change MUX
8. Select SAVE (F1).
9. Select Activ (F1) from the Save to screen.
Command Complete appears to confirm that the
configuration is saved.
4-14February 19953550-A2-GB20-10
12. Press the
13. Select Prt2.
14. Select V.35.
15. Press the
screen.
key to display Prt2.
key twice to return to the Edit/Save
Operating the DSU
16. Select SAVE (F1).
17. Save to Activ (F1).
Command Complete appears to confirm that the
configuration is saved.
Poll List
The Poll List (PList) subbranch maintains or changes
the DSU’s poll list. A control DSU’s poll list includes all
tributary DSUs and DBMs one level downstream.
You can display, clear, change, or acquire a poll list. If
you select Clr (Clear) from the Poll List screen, all
network addresses are erased from the DSU’s poll list.
PList is only available from the Local branch, and only
to a DSU configured for nondisruptive and mixed
diagnostics (Diag Type is set to NonD or Mixed).
Displaying the Poll List
To display each of the network addresses included in
the DSU’s poll list:
Changing the Poll List
To change the poll list (e.g., add network address 3):
.
Procedure
1. Select Chang (F3).
Chng Poll List:
ActivDeletSkip
F1
2. Select Activ (F1).
Address: 2
F1
3. Press the F1 key to increment network address 2.
F2
F2
F3
Enter
F3
.
Procedure
1. Select PList (F2).
2. Select Displ (F1). The following screen appears:
Addr:2 Acti ve
F1
F2
F3
The number after Addr (in this example, 2) is the
network address of the poll list member. The
member is identified as either Active or Skip
(identified via the Change Poll List function).
3. Press the F1 or F2 key to display additional
addresses.
4. Press the
key to return to the Poll List screen.
Address: 3
Enter
F1
F2
F3
4. Select Enter (F3).
Make3 Acti ve:
F2
F3
Command Complete
F1
The address is added to the poll list. The control
determines the round trip delay, then sends that
information to the tributary DSU.
5. Press the
key to return to the Chng Poll List
screen.
4-153550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
To delete a network address (e.g., 3) from the poll list:
.
Procedure
Chng Poll List:
F2
F3
ActivDeletSkip
F1
1. Select Delet (F2).
Address: 3
Enter
F1
F2
F3
2. Select Enter (F3).
In this example, 3 was just added, so it is the
address displayed. If another address needs to be
deleted, change the network address displayed as
previously shown.
Acquiring the Poll List
To automatically generate a poll list:
.
Procedure
Poll List:
DisplClr Chang
F1
1. Press the
2. Select Acq (F1).
key to display Acq.
Poll List:
AcqDisplClr
F1
Acquir Poll List:
Abort
F2
F2
F3
F3
D e l3 frPList:
F2
F3
Command Complete
F1
The tributary DSU associated with the address is
removed from the poll list.
F1
F2
F3
You can stop the process and keep the poll list as it
has been generated by selecting Abort.
Acquir Poll List:
F2
F3
Command Complete
F1
Otherwise, all tributary addresses have been
acquired.
4-16February 19953550-A2-GB20-10
Operating the DSU
Directory
The DSU’s dial backup Directory ( Dir ) can store up to
ten telephone numbers (dial strings) so the DBM can call
other DBMs or modems. Directory entries are numbered
from 1 to 10. Each dial string in the directory can be up to
36 characters in length. Refer to T able 4-6 for numbers
and characters that can be used.
When the dial string or changes are complete, enter an
underscore ( _ ) to the immediate right of the last
character; this ends the dial string field.
NOTE
Do not load duplicate telephone
numbers into the Directory;
telephone numbers should be
unique.
Entering a Telephone Number
For the following example, we will add a dial string
(telephone number) to Backup Directory 1. The number to
be entered is 555-1234.
To add or change a telephone number:
.
Procedure
1. Select Local.
2. Press the
branch).
key to display Confg (Configuration
The Directory entry appears on the first line; the
cursor is positioned in the first position of the
currently empty Directory.
1 :
Undo
F1
F2
F3
If the number had been entered previously, that
number would appear on the first line, following
the colon (:).
For numeric screens, the following applies:
— Press the F1 key (↑) to increment the digit.
— Press the F2 key (↓) to decrement the digit.
— Press the
or keys to move the
blinking cursor one position to the left or
right.
— Press the F3 key (Undo) to restore the number
as it was first displayed so you can start over.
Refer to T able 4-6 to see all available directory
and password entry characters.
7. Press the F1 key until the number 5 appears.
8. Press the
key to move to the next position.
9. Repeat the process until all numbers in the
telephone number have been entered.
3. Select Confg.
4. Select Dir if entering a telephone number into the
Backup Directory.
Press the
key to display then select Phone if
entering the local DSU’s telephone number. This
telephone number is entered similarly to entering
a number into Dir.
5. Select Chang (F1) to add or change a telephone
number.
The Enter Dir screen appears.
Press the F1 key (↑) to increment the Directory
entry indicator (the default is 1). For this example,
assume that you are entering your first directory
entry.
6. Select Load (F2).
1 : 5 5 5 1 2 3 4
Undo
F1
F2
F3
NOTE
A dial string cannot have any
separating characters or spaces
(i.e., 555-1234 or 555 1234).
Other valid characters
can be
interspersed as needed : *, #, t,
p, w, and comma (,).
4-173550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
10. Press the key to return to the Enter Dir
screen.
11. Press the F3 key to Save the entry.
12. Verify that the number was loaded by pressing the
key again and selecting Load (F2).
The telephone number should appear as entered, or you
can repeat the procedure to edit/correct your entry.
Table 4-6
Directory Entry and Password Characters
Character
0—9Dialing digit
, (comma)In a dial string: a 2-second pause at
( ) (space)Space (readability character)
1
*
#Tone-dialing character #
tTone dial
pPulse dial
wWait for dial tone
ť
Tone-dialing character *
Delimiter, separating telephone
number and callback directory
pointer (for use with callback
security)
the beginning of a password;
suppresses display of all following
characters (invisible mode)
Use
2
Network Address
The network address (Addr) is the network address of
the local DSU. It is only available from the Local branch.
The DSU’s network address is a number in the range of
1 to 254 if the DSU has a DBM installed. The DBM
automatically acquires an address equal to the DSU’s
plus 1.
Assigning an Address
The Addressing the Unit sections of the installation
chapters, Chapters 2 and 3, provide guidelines for
assigning an address to the DSU based upon its position in
the network – control or tributary. Follow the steps below
to assign a network address to a DSU. Refer to the menu
in Appendix A, if necessary.
.
Procedure
1. Select Confg (Configuration branch) from the
menu.
(Press the
press the function key (F3) directly below the
branch name to select it.)
2. Press the
then select Addr.
3. Select Load.
Net Address appears, with the current network
address displayed. (The DSU is shipped with its
network address set to 254.)
key to scroll Confg into view, then
key until Addr (Address) appears,
_ (underscore)Required character for end-of-string
marker (erases end-of-line)
1
The colon (:) character should not be entered from
the NMS.
2
Space is not used for directory entries.
Phone
The local telephone number (Phone) feature stores the
local DBM’s telephone number if a DBM is installed.
Refer to T able 4-6 to see all available telephone
number characters.
4. Change the DSU’s network address by moving the
blinking cursor and incrementing or decrementing
the digits (1 through 9).
Press the
key – moves the cursor 1
position to the right.
Press the
key – moves the cursor 1
position to the left.
Press the F1 (↑) key – increments the digit by
1 (e.g., 1, 2, 3 ...).
Press the F2 (↓) key – decrements the digit by
1 (e.g., 1, 2, 3, ...).
5. Press the
key to return to the Net Addr ess
screen when finished entering the DSU’s address.
4-18February 19953550-A2-GB20-10
Operating the DSU
6. Select Save (F2).
The DSU displays the address assigned along with
a Command Complete message.
If an error was made in entering the address:
.
Procedure
1. Press the
screen.
2. Re-select Addr, and re-edit the address.
3. Select Save again.
key to return to the Configure
Control Branch
The Control (Ctrl) branch allows you to enable or
disable the DSU’s transmitter, as well as the DBM’s or
port’s, and to display or change the status of the general
purpose external DTE leads. A DBM can be disabled if it
is addressed from the Remote branch.
Transmitter Control
LEDs
The LEDs selection is only available from the Local
branch. This selection allows you to monitor the port at
any given time. When selected, the port’s lead activity is
reflected in the DCP circuit designation status indicators
(TXD, RXD, etc.) on the faceplate of the Model 3551
DSU, or on the DCP of the Model 3550 DSU.
External Leads
The External Leads (ExtL) selection allows you to
display the state of four general-purpose leads on the
EIA-232-D/V.24 Port 1 interface: Pins 12 and 13 for
output (control leads) and Pins 19 and 23 for input (alarm
leads).
When the configuration option Ext Leads (External
Leads) is set to ExtLd, you can change the state of the two
output leads from the DCP or a 6700 Series NMS. When
CCN by EL (CCN by External Leads) is enabled, the
control DSU reports changes in the four leads to the 6700
Series NMS as part of its health and status poll response.
Table 4-7 describes the meaning of the state of each
input or output lead.
The Transmitter Control (TxCtl) selection allows you
to enable or disable the DSU’s, DBM’s, or port’s
transmitter (DDS core).
When the DSU transmitter is disabled, the following is
possible:
• When a DSU is disabled, it responds to tests.
Aborting a test clears the test but the unit remains
disabled.
• A DSU in test clears the test when a disable (or
enable) command is received.
• If an enable command is executed to a control from
the NMS or the local DCP, all disabled tributaries
are enabled; all tributaries in test are restored to
Data mode.
When the local DBM is disabled, the DBM does not
originate or answer any calls until enabled.
Displaying External Leads
The Display (Displ) selection allows you to view the
external lead states. When Display is selected, the
External Leads status report appears showing the current
status of the general-purpose external leads on the
EIA-232-D/V.24 interface.
Changing External Leads
The Change (Chang) selection allows you to change
the state of the two output leads (for example, to change a
lead to signal a console operator or to reset a remote
computer). Leads can be changed from the NMS.
After the leads are set, press the F2 key to save the
leads in the specified state.
4-193550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
Table 4-7
Lead States
Symbol
Off (below text line)
ON (above text line)
Changing
?
NOTES:
Input leads A and B:
) when voltage on lead is less than +.8V.
Off (
) when voltage on lead is more than +2.2V.
ON (
Output leads are either ON or Off:
When output is set to Off (
When output is set to ON (
Indicates an illegal value
), –12V is applied to lead.
), +12V is applied to lead.
Reporting External Lead Changes to NMS
Changing either the output leads or the input leads
changes the DSU’s health and status message.
If the DSU is polled by the 6700 Series NMS, the NMS
reports a change configuration notification (CCN) event.
The NMS operator can then issue a CCN Display
command to determine what caused the event.
• If the CCN event was caused by a change in the
external leads, select Displ (F1) to see the current
states of the leads.
• If a positive (+) voltage is detected in either one of
the input leads, an external leads alarm is also
reported.
Meaning
To receive messages:
.
Procedure
1. Press the F3 key (Msgs).
2. Select Read (F1).
3. If the message is less than 16 characters in length,
the entire message is displayed.
If the message is greater than 16 characters, press
key to scroll additional lines of the
the
message onto the screen.
To clear (delete) messages:
.
Procedure
1. Press the F3 key (Msgs).
Messages Branch
The Messages (Msgs) branch of the top-level menu
allows the DSU to receive messages from the NMS. It
only appears when there is a message waiting. Both
control and tributary DSUs can receive messages.
4-20February 19953550-A2-GB20-10
2. Select Clear (F2).
The message is deleted, and Msgs no longer
After the DSU has been installed and any necessary
hardware switches or jumpers have been set, the software
configuration options must be set. Configuration options
are set via the DCP by accessing the Configuration
(Confg) branch of the menu (refer to the menu tree in
Appendix A).
There are seven configuration storage areas within the
DSU:
• The active area (Activ) contains the configuration
options currently being used by the DSU.
• The remote area (Remt) allows a selected DSU’s
configuration options to be retrieved. Once
retrieved, they can be edited, and/or saved back to
the selected DSU, another DSU, or the local DSU.
Activ and Usr1 are the remote configuration option
sets that can be retrieved.
• The user 1 area (Usr1) is a customer-defined set of
stored configuration options. By predetermining
and storing a frequently used configuration, the
stored option set can be loaded quickly as operating
requirements change.
NOTE
The PTPC, PTPT, MPTC, and
MPTT areas are read-only
storage areas (configuration
option changes cannot be saved
to these areas).
• The factory-loaded configuration option sets for a
point-to-point control DSU are contained in the
PTPC area.
• The factory-loaded configuration option sets for a
point-to-point tributary DSU are contained in the
PTPT area.
• The factory-loaded configuration option sets for a
multipoint control DSU are contained in the MPTC
area.
• The factory-loaded configuration option set for a
multipoint tributary DSU are contained in the
MPTT area.
NOTE
Load the appropriate option set
(PTPC, PTPT, MPTC, or MPTT)
when installing or upgrading the
DSU.
Selecting Activ, Usr1, PTPC, PTPT, MPTC, or MPTT
from the Load from screen brings a complete set of
configuration options into the DSU’s working buffer.
These configuration options are grouped by their function.
These groupings are referred to as option sets. Each of
these option sets, or groupings, control a specific aspect of
the DSU’s operation.
5-13550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
Once loaded, the following Edit/Save submenu
appears:
Edit/Save:
SAVEDSUDBM
F1
Press the or key to scroll the following
configuration option sets into view: DSU, Diagnostic
(DSU, DBM, External DBU, and General), DBM,
External DBU, General, Backup, MUX (Copy, Setup, and
Ports), and Port Speed (DSU, DBM, and External DBU).
If your unit has a DBM installed, the External DBU
option sets will not appear. If your unit does not have aDBM installed, the DBM option sets will not appear. The
Backup option set only appears when a DBM is installed
or an external DBU is configured to originate backup;
otherwise, the Backup option set will not appear. If the
unit does not have a TDM/Flex installed, the MUX and
Port Speed option sets will not appear.
F2
F3
Using the DCP to
Set Configuration Options
Configuration options can be edited and saved to either
the Activ or Usr1 areas. This section provides guidelines
for using the DSU’s diagnostic control panel (DCP) to
perform these operations.
4. Select storage area (Activ, Remt, Usr1, etc.) from
the Load from screen.
If the unit is a control and you select Remt, enter
the network address of the remote DSU.
5. Select the option set (e.g., DSU, Diag, DBM) to
be edited.
The first configuration option within that set
appears. Page through each configuration option
within the set as follows:
a. Press the F1 key to go to the Next
configuration option. These configuration
options scroll or wrap around (e.g. first, then
last; or last, then first).
b. To return to the previous configuration option,
press the
Prev appears over the F1 key.
c. Select Prev by pressing the F1 key.
As you edit configuration options, be aware of the
following:
• The first line of each configuration option identifies
the option and its current setting.
If configuration data has been corrupted, ??? will
appear in place of the current value. If this occurs,
reset all configuration options, along with the
network address. If a DBM is installed, check the
Backup Directory entries, the poll list, and the
DSU’s local telephone number as well.
key instead of selecting Next.
In addition, an example is included to illustrate DCP
operation.
Editing Configuration Values
To edit or change configuration options:
.
Procedure
1. Select Local, or Remot (Remote) and the remote
DSU’s network address.
2. Select Confg (Configuration branch).
Press the
press the function key (F1, F2, or F3) directly
below Confg.
3. Select Opts (Configuration Options).
5-2February 19953550-A2-GB20-10
key key until Confg appears, then
• The second line displays all values that are
available for selection – three at a time, one above
each function key.
— Press the
selections into view.
— Press the function key (F1, F2, or F3) directly
below a value to select it.
— Select Next to proceed to the next option.
— Select Prev to return to a previous option.
— Press the
submenu or screen, and select the next option
set to be edited.
or key to scroll other
key to return to the Edit/Save
Saving Configuration Options
CAUTION
Be extremely careful when saving
configuration options to avoid
saving them to the wrong
location.
Configuring the Unit
.
Procedure
Press the DCP keys indicated by the shading.
Port 1 DSU9.6 C
Local Remot
F1
F2
F3
To save edited configuration options:
.
Procedure
1. From any configuration option in any option set,
press the
key to return to the Edit/Save
submenu.
2. Press the F1 key below SAVE.
3. Select area (Activ, Remt, Usr1) on the Save to
screen.
• If Activ is selected, your changes take effect
immediately.
• If Usr1 is selected, your changes are stored for
future use.
• If the unit is a control and Remt is selected, the
complete set (all option sets available to the
unit) of configurations are sent to the tributary
and saved to its Activ area.
Remember that you cannot save to the factoryloaded configurations.
Example Using the DCP
In this example, load the configuration options stored
in the PTPT area, change Diagnostic T ype (Diag Type)
under the Diagnostic (DSU) option set from Disr to
NonD, change DTE Port under the General option set
from EIA232 to V.35, then save the changes to the Usr1
area, and return to the main or top-level menu.
Local Mode:
StatBckupTest
F1
F2
F3
Local Mode:
BckupTestConfg
F1
F2
F3
Configure:
OptsPListDir
F1
F2
F3
Load from:
Activ Remt Usr1
F1
F2
F3
Load from:
Remt Usr1PTPC
F1
F2
F3
Load from:
Usr1PTPCPTPT
F1
F2
F3
5-33550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
Edit/Save:
SAVEDSUDiag
F1
F2
F3
Chang Diag Opts:
DSUDBMGen
F1
F2
F3
Diag Type: Disr
NextNonDDisr
F1
F2
F3
Diag Type: NonD
NextNonDDisr
Edit/Save:
DiagDBMGen
F1
F2
F3
DTE Port: EIA232
NextEIA232 V.35
F1
F2
F3
DTE Port: V.35
NextEIA232 V.35
F1
F2
F3
Edit/Save:
SAVEDSUDiag
F1
F2
F3
Chang Diag Opts:
DSUDBMGen
F1
F2
F3
Edit/Save:
SAVEDSUDiag
F1
F2
F3
Edit/Save:
DSUDiagDBM
F1
F2
F3
F1
F2
F3
Save to:
ActivUsr1PTPC
F1
F2
F3
Save to: Usr1
Please wait . . .
F1
F2
F3
Save to: Usr1
Command Complete
F1
F2
F3
5-4February 19953550-A2-GB20-10
Configuring the Unit
Port 1 DSU9.6 T
Local Remot
F1
F2
F3
This example is now complete.
Configuration Option Tables
This section contains a table for each option set that
can be found under the Configuration (Confg) branch, in
the order in which it appears in the menu.
Each table lists all configuration options available
within the option set when Menu mode is enabled (Menu
subbranch – Full Mode: Enab). Appendix B provides
Configuration Worksheets that summarize the
configuration options when Menu mode is enabled, as
well as when it is disabled.
This chapter includes the following option set tables:
• DSU Configuration Options (Table 5-1)
• Diagnostic (DSU) Configuration Options
(Table 5-2)
• Diagnostic (DBM) Configuration Options
(Table 5-3)
• Diagnostic (External DBU) Configuration Options
(Table 5-4)
• Diagnostic (General) Configuration Options
(Table 5-5)
• DBM Configuration Options (Table 5-6)
• External DBU Configuration Options (Table 5-7)
• General Configuration Options (Table 5-8)
• Backup Configuration Options (Table 5-9)
• MUX (Setup) Configuration Options (Table 5-10)
• MUX (Port) Configuration Options (Table 5-11)
• Port Speed (DSU) Configuration Options for DSU
(Table 5-12)
• Port Speed (DBM) Configuration Options
(Table 5-13)
• Port Speed (External DBU) Configuration Options
(Table 5-14)
Understanding the Tables
Refer to the appropriate tables when configuring the
DSU. Each configuration option is segmented into three
sections: the option as it appears on the DCP, an
explanation of the option, then the values that can be
selected or set.
Each table shows each configuration option as it is
displayed. As you refer to these tables, be aware of the
following:
• The first line shows each configuration option as
it appears on the DCP, followed by a colon (:), then
the default setting (the value set at the factory).
• The second line shows all selectable values, which
can be viewed on the DCP by scrolling to the left or
right using the
The first selection is always Next, which allows
you to go to the next configuration option in the set.
The last selection is always Prev, which allows you
to go back to the previous configuration option.
Possible selections wrap around so you can
immediately press the
saving key presses.
An explanation of that configuration option and its
selectable values follow, which includes:
• The full or unabbreviated name of the configuration
option, followed by a brief explanation of its
purpose or function.
or key.
key to display Prev,
• The selectable values for the configuration option,
which are listed with guidelines for when each
should be selected.
Int—Select internal clock source to take timing from the DSU.
Ext—Select external clock source when timing is taken from the external Transmit Timing lead on Port 1 only
. Sets the data rate (in kbps) of the DSU, which must be set to match the speed of the digital (DDS) circuit.
(not displayed with a TDM/Flex installed). Sets the speed of the DTE port interface. The port speed is set to
less than
or
equal to
. Specifies the transmit timing source for the DSU.
the DSU Rate(Kbps) set above. The DSU performs rate adaption if the port speed is set
.
(not displayed if a TDM/Flex is installed).
Prt1 or —Select the port that timing is to be taken from, using the selected port’s external Transmit
Prt2Timing lead
DDS—Select the DDS network when the DSU is connected to a DDS network and the network provides the
timing, or when a LADS configuration with a remote DSU is providing the timing.
(Prt2 is only displayed if a TDM/Flex is installed and enabled).
Msg Clamp: Enab
Next Enab Disab Prev
Message Clamping
tests and commands are received from the remote DSU. It applies to both the DSU and DBM.
Enab—Select to prevent diagnostic messages from reaching the DTE interface.
Disab—Select if the remote DSU is configured for switched RTS; that is, RTS Control is set to DTE in the General
TxElasStor: Disab
Next Enab Disab Prev
Transmit Elastic Store
buffer on the DSU’s transmitted data (TXD) lead, serial data is clocked into the DSU’s elastic store using clock provided
by the extended circuit received clock lead. The DSU’s own system timing is used to clock data out of the buffer.
Transmit Elastic Store is reset each time the unit powers-up, the buffer overflows, or after the RTS lead makes an
Off-to-ON transition.
Enab—Select enable when interfacing with a DCE that receives clock from its own network source (e.g., a T1
Disab—Select disable if you do not have an extended network or are providing the clock source to the extended
5-6February 19953550-A2-GB20-10
(only displayed when Full Mode is enabled). Controls data lead behavior when disruptive diagnostic
(Gen) configuration options.
(only displayed when Full Mode is enabled and a TDM/Flex is not installed). Using a transmit
MUX or DSU that is on the DDS network).
network (e.g., LADS with external clock).
RxElasStor: Disab
Next Enab Disab Prev
Configuring the Unit
Table 5-1
(2 of 2)
DSU Configuration Options
Receive Elastic Store
the DSU’s received data (RXD) lead. This configuration option only supports single-port DSUs configured for disruptive
diagnostics (
and tributary DSUs must be configured the same.
Enab—Select enable when interfacing with a DCE that receives clock from its own network source and does not
Disab—Select disable if you do not have an extended network.
19.2 PowrLvl: +6
Next +6 0 –10 Prev
Diag Type
19.2 kbps Power Level
configuration option selects the appropriate power level, in dBm, for operation at 19.2 kbps.
+6—Select for DDS network service.
0—Select for an alternate DDS service.
–10—Select for LADS operation.
V.54 Lpbk: Disab
Next Enab Disab Prev
V .54 Loopback
option enables CCITT V.54 Loopback operation. V.54 sequences are generated and detected on Port 1.
Enab—Select enable if the DTE generates V.54 loopback sequences, or if the DSU is communicating with a DSU
Disab—Select disable if the DTE does not support V.54 loopback sequences, or the other DSUs do not support
(only displayed when Full Mode is enabled). The DSU receives data using a receive data buffer on
is set to Disr) and no rate adaption – when
support a Transmit Elastic Store.
(only displayed when Full Mode is enabled and when Rate(Kbps) is set to 19.2 kbps. This
(only displayed when Full Mode is enabled). Used in point-to-point configurations, this configuration
that is not a Model 3550 or 3551 that supports V.54signaling.
V.54 signaling.
Rate(Kbps)
is equal to
PrtSp(Kbps
). Both the control
5-73550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
Diagnostic (DSU) Configuration Options
Diag Type: Disr
Next NonD Disr Mixed None Prev
Table 5-2
Diagnostic Type
DSUs on the same circuit should be set the same (e.g., if the control is set to NonD, all its tributaries should also be set
to NonD).
NonD—Select nondisruptive diagnostics for diagnostic data to be transmitted between the control and the
Disr—Select disruptive diagnostics for diagnostic data to be carried between the control and the tributary DSUs
Mixed—Select if operating over a multipoint network. This setting supports nondisruptive health and status
None—Select none if only local diagnostics are to be allowed; that is, there will be no diagnostic communications
2nd Ch(bps): 400
Next 100 400 800 1200 1600 Prev
In-band Secondary Channel Diagnostic T ransport Speed in bps
Mode is enabled). This configuration option allocates the DSU’s port bandwidth when there is no excess bandwidth
available for in-band secondary channel transport (used for diagnostic data) operation.
How to Select Bandwidth: Select one of the valid diagnostic speeds from the table below for the DSU’s port and the
DDS line’s speed, as specified in the
Rate(Kbps)
resulting DSU port speed will be 9.2 kbps.)
NOTE: When The TDM/Flex is operating at a line rate greater than 19.2 kbps or with a multipoint configuration,
If the DSU
if the underspeed port speed and sum of the
TDM/Flex ports is equal to the
aggregate speed on the DSU:Valid diagnostic speeds are:
. This configuration option defines the diagnostic interaction between control and tributary DSUs. All
tributary DSUs over a separate diagnostic channel.
over the same (primary) channel as user-transmitted data. User-initiated commands are sent between the
control and the tributary DSUs disruptively, interrupting data.
updates, but user-initiated commands are sent between the control and the tributary DSUs disruptively ,
interrupting data.
with remote devices.
(only displayed when Diag Type is set to NonD and Full
configuration option is set to 9.6 kbps, you can select 100, 400, 800, 1200, or 1600. If you select 400, the
Rate(Kbps)
100 bps is not a valid in-band secondary channel transport rate.
Rate(Kbps)
is equal to Port Speed, or
configuration option under the DSU option set. (Example: If the DSU’s
5-8February 19953550-A2-GB20-10
Diagnostic (DBM) Configuration Options
Diag Type: Disr
Next NonD Disr Mixed None Prev
Configuring the Unit
Table 5-3
Diagnostic Type
in backup. All DSUs on the same circuit should be set the same (e.g., if the control is set to NonD, all its tributaries
should also be set to NonD).
NonD—Select nondisruptive diagnostics for diagnostic data to be transmitted between the control and the
Disr—Select disruptive diagnostics for diagnostic data to be carried between the control and the tributary DSUs
Mixed—Select if operating over a multipoint network. This setting supports nondisruptive health and status
None—Select none if only local diagnostics are to be allowed; that is, there will be no diagnostic communications
2nd Ch(bps): 400
Next 100 400 800 1200 1600 Prev
In-band Secondary Channel Diagnostic T ransport Speed in bps
Mode is enabled). This configuration option allocates the DBM’s port bandwidth when there is no excess bandwidth
available for in-band secondary channel transport (used for diagnostic data) operation.
How to Select Bandwidth: Select one of the valid diagnostic speeds from the table below for the DBM’s port and the
DBM’s rate, as specified in the
Rate(Kbps)
resulting DBM port speed will be 9.2 kbps.)
NOTE: When The TDM/Flex is operating at a line rate greater than 19.2 kbps or with a multipoint configuration,
If the DBM
if the underspeed port speed and sum of the
TDM/Flex ports is equal to the
aggregate speed on the DBM:Valid diagnostic speeds are:
1.2100, 400
2.4100, 400, 800
4.8100, 400, 800, 1200, 1600
9.6100, 400, 800, 1200, 1600
12.0100, 400, 800, 1200
14.4100, 400, 800, 1200, 1600
. This configuration option defines the diagnostic interaction between control and tributary DSUs that are
tributary DSUs over a separate diagnostic channel.
over the same (primary) channel as user-transmitted data. User-initiated commands are sent between the
control and the tributary DSUs disruptively, interrupting data.
updates, but user-initiated commands are sent between the control and the tributary DSUs disruptively ,
interrupting data.
with remote devices.
(only displayed when Diag Type is set to NonD and Full
configuration option is set to 9.6 kbps, you can select 100, 400, 800, 1200, or 1600. If you select 400, the
Rate(Kbps)
100 bps is not a valid in-band secondary channel transport rate.
Rate(Kbps)
is equal to Port Speed, or
configuration option under the DBM option set. (Example: If the DBM’s
5-93550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
Diagnostic (External DBU) Configuration Options
Diag Type: Disr
Next Disr None Prev
Table 5-4
Diagnostic Type
in backup using an
control is set to Disr, all its tributaries should also be set to Disr).
Disr—Select disruptive diagnostics for diagnostic data to be carried between the control and the tributary DSUs
None—Select none if only local diagnostics are to be allowed; that is, there will be no diagnostic communications
. This configuration option defines the diagnostic interaction between control and tributary DSUs that are
external
over the same (primary) channel as user-transmitted data. User-initiated commands are sent between the
control and the tributary DSUs disruptively, interrupting data.
with remote devices.
dial backup unit (DBU). All DSUs on the same circuit should be set the same (e.g., if the
Table 5-5
(1 of 2)
Diagnostic (General) Configuration Options
Position: Cntrl or Trib
Next Cntrl Trib Prev
Network Position
diagnostic capabilities.
Cntrl—Select if the DSU is a control (PTPC or MPTC configuration).
Trib—Select if the DSU is a tributary (PTPT or MPTT configuration).
LinkConfig: Pt-Pt or M-Pt
Next Pt-Pt M-Pt Prev
Link Configuration
testing, dial backup, unit operation, and is required when using nondisruptive diagnostics.
Pt-Pt—Select for a point-to-point configuration (PTPC or PTPT configuration).
M-Pt—Select for a multipoint configuration (MPTC or MPTT configuration).
. This configuration option determines the DSU’s position in the network, as well as its test and
. Used to define a point-to-point or multipoint circuit, this configuration option is required for proper
Resp Period: 1
Next 1 2 10 Prev
Response Period
is enabled). Used for single-port multipoint applications and applicable to
configuration option determines how often health and status messages are transmitted, which are transmitted each time
the Request-to-Send (RTS) lead is raised.
1—Select if you want the tributary DSU to transmit health and status information
2—Select if you want the tributary DSU to transmit health and status information
10—Select if you want the tributary DSU to transmit health and status information
5-10February 19953550-A2-GB20-10
(only displayed when any Diag Type is set to NonD or Mixed, LinkConfig is set to M-Pt, and Full Mode
(
not
applicable for PTPC, PTCT, or MPTC configurations).
raised.
raised.
tributary
DSUs and DBMs only. This
every time
RTS is raised
every other time
every 10th time
that RTS is
that RTS is
TribTimOut: 0:10
Next Chang Prev
Configuring the Unit
Table 5-5
(2 of 2)
Diagnostic (General) Configuration Options
Tributary Time-out
LinkConfig is set to M-Pt, and Full Mode is enabled). This configuration option specifies the amount of time that the
control DSU or DBM waits before it generates a Tributary Time-out alarm when a tributary does not return a health and
status message when RTS is raised (
Chang —Determine the amount of time it takes for the control DSU to complete its polling cycle, then multiply that
Link Delay: 0s
Next 0s 1s 2s 5s 10s 20s 50s Prev
Link Delay
Mode is enabled). Used only in point-to-point configurations, this configuration option controls the amount of additional
time that a DSU or DBM will wait for a response from a device downstream (
NOTE: If diagnostic time-outs are occurring during polling, increase the link delay to the next higher setting.
0s to 50s—Set the number of seconds the DSU or DBM will wait for a response from the downstream device. The
Packet Delay: 0s
Next 0s 1s 2s 5s Prev
, specified in seconds (only displayed when any Diag Type is set to NonD, LinkConfig is set to Pt-Pt, and Full
Packet Delay
a control DSU or DBM, this configuration option controls the amount of time that a DSU or DBM will wait for a packet to
complete from an NMS.
NOTE: Must be used when the DSU’s diagnostic channel operates over packet switch, satellite communications, or
0s to 5s—Set the amount of time the DSU or DBM will wait for the NMS. The range that can be entered is from
other facilities that provide extended throughput delays.
, specified in minutes and seconds (only displayed when any Diag Type is set to NonD or Mixed,
only
applies to a MPTC configuration).
time by the response period entered above (Resp Period). The range that can be entered is from 5
seconds up to 10 minutes.
only
applies to a PTPC configuration).
range that can be entered is from 0 seconds up to 50 seconds.
, specified in seconds (only displayed when Position is set to Cntrl and Full Mode is enabled). Used only for
0 seconds up to 5 seconds.
M-PtSymPrt:Enab
Next Enab Disab Prev
Multipoint Symmetrical Port
multipoint configuration, This configuration option enables rate adaption in the tributary DSU to control direction on a
multipoint circuit. An example of multipoint rate adaption would be when the port speed is
applies to MPTC and MPTT configurations).
Use this configuration option when using multipoint rate adaption, or when the transmit data rate must match the
received data rate, or the tributary DSU is configured as a digital-sharing device (DSD).
Enab—Select when multipoint rate adaption is enabled, and when a multipoint network is configured for
nondisruptive diagnostics (
DTE operation.
Disab—When disabled, the receive port rate on the control will be the DDS rate, and the transmitter will be the
port rate, minus the diagnostics.
(only displayed when LinkConfig is set to M-Pt and Full Mode is enabled). Used only in a
Diag Type
less than
is set to NonD) and a symmetrical port speed is required for proper
the line speed (
only
5-113550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
DBM Configuration Options
Rate(Kbps): 9.6
Next 14.4 12.0 9.6 4.8 2.4 Prev
Table 5-6
(1 of 4)
DBM Rate
14.4 to —Select the data rate for V.32bis modulation. The rate 14.4 is not displayed if you have a 12.0 kbps DBM.
4.8 kbps
2.4—Select for V.22bis modulation.
PrtSp(Kbps): 9.6
Next 14.4 12.0 9.6 4.8 2.4 1.2 Disab Prev
Port Speed
speed is set to any value
less than
14.4 to —Select the port speed for the DBM; 14.4 will not appear for a 12.0 kbps DBM.
1.2 kbps
Disab—Select disable to set the port speed to 0.
TxClkSource: Int for a control DBM; RXC for a tributary DBM
Next Int RXC Ext Prt1 Prt2 DSU Prev
Transmit Clock Source
Int—Select internal clock source to take timing from the DBM. This setting is used primarily in point-to-point
RXC—Select receive clock source to take timing from the remote DBM’s clock source.
Ext—Select external clock source when timing is taken from the external Transmit Timing lead on Port 1
. Sets the initial data rate (in kbps) of the DBM for backup calls over the dial circuit.
(not displayed with a TDM/Flex installed and enabled). Sets the speed of the DTE port interface. The port
the DBM port rate.
applications.
less than
. Specifies the transmit timing source for the DBM.
or
equal to
the DBM Rate(Kbps) set above. The DBM performs rate adaption if set to
(not
displayed if a TDM/Flex is installed).
Prt1 or —Select the port that timing is to be taken from, using the selected port’s external Transmit
Prt2Timing lead
DSU—Select the DSU’s clock source when connected to a DDS network and the network is to provide the
timing.
(displayed if a TDM/Flex is installed and is enabled).
Do not select DSU if the DSU and the DBM operate at different rates.
CarrLossDisc: Yes
Next Yes No Prev
Carrier Loss Disconnect
receive signal carrier is lost, or when the signal is no longer acceptable.
Yes—Select when you want to terminate the backup call when the carrier is lost.
No—Never select; for factory testing only. Selecting No will cause an off-hook line condition, which will result in
excessive telephone charges.
Auto Retrain:Yes
Next Yes No Prev
Automatic Retrain
automatically when received signal quality is no longer acceptable.
Yes—Select if you want the DBM to retrain automatically.
No—Select if you
request from a remote modem or DBM.
5-12February 19953550-A2-GB20-10
(only displayed when Full Mode is enabled). Controls whether the DBM terminates a call when
(only displayed when Full Mode is enabled). Controls whether the DBM will start a retrain sequence
do not
want the DBM to retrain automatically . However, the DBM will respond to a retrain
Single Rate: Yes
Next Yes No Prev
Configuring the Unit
Table 5-6
(2 of 4)
DBM Configuration Options
Single Rate
rate mismatch with a remote DBM or modem with the following limitations.
NOTE: If the DBM Rate(Kbps) is set to 2.4, the DBM will only train at 2.4 kbps and can only talk to a 2.4 kbps modem,
Yes—Select when you want the DBM to only operate at the rate for which it is configured.
No—Select when you want the DBM to adjust its rate downward to correct a rate mismatch.
AutoAnswer: Enab
Next Enab Disab Prev
Automatic Answer
Enab—Select if the DBM is to automatically answer incoming calls.
Disab—Select if the DBM is
TxElasStor: Disab
Next Enab Disab Prev
Transmit Elastic Store
buffer on the DBM’s transmitted data (TXD) lead, serial data is clocked into the DBM’s elastic store using clock provided
by the extended circuit received clock lead. The DBM’s own system timing is used to clock data out of the buffer.
Transmit Elastic Store is reset each time the unit powers-up, the buffer overflows, or after the RTS lead makes an
Off-to-ON transition.
Enab—Select enable when interfacing with a DCE that receives clock from its own network source (e.g., a T1
Disab—Select disable if you do not have an extended network or are providing the clock source to the extended
(only displayed when Full Mode is enabled). Determines whether the DBM will adjust its rate to resolve a
regardless of how Single Rate is set.
(only displayed when Full Mode is enabled). Controls whether the DBM answers incoming calls.
not
to automatically answer incoming calls.
(only displayed when Full Mode is enabled and a TDM/Flex is not installed). Using a transmit
MUX or DSU that is on the DDS network).
network (e.g., LADS with external clock).
RxElasStor: Disab
Next Enab Disab Prev
Receive Elastic Store
on the DBM’s received data (RXD) lead. This configuration option only supports single-port DBMs configured for
disruptive diagnostics (
the control and tributary DBMs must be configured the same.
Enab—Select enable when interfacing with a DCE that receives clock from its own network source and does not
Disab—Select disable if you do not have an extended network.
(only displayed when Full Mode is enabled). The DBM receives data using a receive data buffer
Diag Type
support a Transmit Elastic Store.
is set to Disr) and no rate adaption – when
Rate(Kbps)
is equal to
PrtSp(Kbps
). Both
5-133550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
DBM Configuration Options
Call Setup:None
Next None Pswrd Cllbk Alarm Prev
Table 5-6
(3 of 4)
Dial Backup Call Setup
attempts. This configuration option prevents an invalid call from causing the DSU to switch data to the DBM.
None—Select for outgoing calls when no security is needed. If a Model 3550 or 3551 DBM calls, the unit
automatically switches to Dial Backup mode. If a non-Model 3550 or 3551 DBM calls, the unit remains in
Standby mode for 15 seconds before switching to Dial Backup mode.
Pswrd—Select when both the originating and answering DBMs must exchange valid passwords to establish a call.
This is an intermediate security level. Both devices must be either Model 3550 or 3551 DSUs and DBMs.
Cllbk—Select when you want the highest level of security. When this security level is set, the originating and
answering DBMs exchange passwords, then disconnect. The answering DBM then calls the originating
DBM back and there is a second exchange of passwords. Both devices must be either Model 3550 or
3551 DSUs and DBMs.
Alarm—Select when the DBM is to answer incoming calls only after the DSU reports a Facility Alarm. No security
checking is performed. (This feature is provided for customers that provide data services to other
customers that may not have Model 3550 or 3551 DSUs and DBMs.)
RxPwd: password
Next Chang Prev
Receive Password
DBM expects to receive a password from the remote DBM. This password
(TxPwd). The maximum password length is 10 characters. Refer to Chapter 4 for available password characters.
Chang —Select and then enter the remote DBM’s transmit password as the local DBM’s receive password. For
passwords less than 10 characters long, enter an underscore ( _ ) to the immediate right of the last
character in the password.
(only displayed when Full Mode is enabled). Establishes the level of security for call setup
(only displayed when Call Setup is set to Callbk or Pswrd, and when Full Mode is enabled). The
must be
the remote DBM’s transmit password
To make the password invisible from the DCP, enter a comma ( , ) as the first
character.
TxPwd: password
Next Chang Prev
Transmit Password
DBM expects to transmit a password to the remote DBM. This password
(RxPwd). The maximum password length is 10 characters. Refer to Chapter 4 for available password characters.
Chang —Select and then enter the remote DBM’s receive password as the local DBM’s transmit password. For
(only displayed when Call Setup is set to Callbk or Pswrd, and when Full Mode is enabled). The
passwords less than 10 characters long, enter an underscore ( _ ) to the immediate right of the last
character in the password.
To make the password invisible from the DCP, enter a comma ( , ) as the first
must be
the remote DBM’s receive password
character.
5-14February 19953550-A2-GB20-10
Table 5-6
(4 of 4)
DBM Configuration Options
V.13 Signl: Enab for MPTC and MPTT; Disab for other configurations
Next Enab Disab Prev
Configuring the Unit
V .13 Signaling
Backup mode. The normal RTS/CTS delay is 14 ms at 2.4 kbps and 11 ms at all other speeds when V.13 is enabled. It is
under 2 ms when V.13 is disabled.
For the V.13 sequence to be generated by a
CTS Cntrl set to Std or Delay . For the V.13 sequence to function at the
Lead must be set to Std.
NOTE: Although this configuration option must be enabled in both the tributary and control DSUs in order to use
Enab—Select when backing up a circuit that is configured for nondisruptive or mixed diagnostics or rate
Disab—Select when configured for point-to-point nondisruptive diagnostics or point-to-point rate adaption; V.13
Dial Test:Disab
Next Enab Disab Prev
Dial Tone Test
dial tone. If the test fails, the DSU reports a Dial Test Failure alarm in its health and status reports. A Dial Test occurs
once every 60 minutes until a failure occurs. Then, the test repeats every minute until the network recovers.
Enab—Select to perform a Dial Tone testing.
Disab—Set to Disable if the DBM is not to perform Dial Tone testing.
DTRCallCon:Disab
Next Ansr Disab Prev
(only displayed when Full Mode is enabled). V.13 signaling applies to the DBM when the DBM is in Dial
tributary
V.13 signalling, RTS Cntrl propagation only occurs in the tributary-to-control direction.
adaption. When enabled at both ends, LSD is turned ON at the control while RTS is ON at the tributary,
and is turned Off when RTS is turned Off at the tributary DBM. The V.13 sequence is sent over the
network to tell the control to turn ON LSD (
Signaling is turned Off.
(only displayed when Full Mode is enabled). When enabled, the DBM periodically checks for a signal or
DBM, the following must be set: RTS Cntrl must be set to DTE,
only
for a MPTC or MPTT configuration).
control
DBM, the following must be set: LSD
Data Terminal Ready Call Control
lead to control backup when contact with the remote DSU is lost.
Ansr—Select answer when the DTR lead is used for
remote DBM when DTR is raised. It drops the call when DTR goes low or will not answer an incoming call
if DTR is low.
Disab—Select to disable DTR Call Control; the state of the DTR lead is ignored.
(only displayed when Full Mode is enabled). DTRCallCon uses the state of the DTR
DCE—Select if clock is provided by the
Prt1 or —Select the port that timing is to be taken from, using the selected port’s external Transmit
Prt2Timing lead
. This feature allows dial backup for a DSU using an
external
external
Backup option set be available. The
. Specifies the transmit timing source for the
DBU to answer an incoming dial backup call.
DBU to originate dial backup. Only when the
external
external
DBU. This is the default setting.
.
external
external
DBU must be set for Dial on DTR.
DBU’s port speed.
DBU.
(Prt2 is only displayed if a TDM/Flex is installed and enabled).
external
external
dial backup unit (DBU).
external
DBU.
DBU is set to Orig will the
5-16February 19953550-A2-GB20-10
DTE Port: EIA232
Next EIA232 V.35 Prev
Configuring the Unit
Table 5-8
(1 of 4)
General Configuration Options
DTE Port
EIA232 —Select when using the EIA-232 interface (connector). EIA232 operation is recommended for speeds
V.35—Select when using the V.35 interface (connector). Operation at available rates for distances up to 1000
RTS Cntrl: DTE for MPTT; FrcOn for other configurations
Next FrcOn DTE Prev
Request-to-Send Control
set to FrcOn, the DSU internally forces the RTS lead ON; if set to DTE, the DSU sends control mode idle (CMI)
whenever RTS is Off, and data mode idle (DMI) when RTS is ON.
FrcOn—Select for PTPC, PTPT, and MPTC configurations. With this setting, the DSU internally forces data mode
DTE—Select for MPTT configuration. This setting causes the DSU to send a control mode idle (CMI) signal
CTS Cntrl: Std
Next Std =RTS Delay FrcOn Prev
Clear-to-Send Control
Test Mode), as determined by the configuration options RTS Cntrl and Circ Assur.
Std—Select for all factory-loaded configurations (PTPC, PTPT, MPTC, and MPTT) so that the DSU responds to
=RTS—When selected, CTS follows RTS regardless of whether Test Mode, an alarm, or CMI is being received.
Delay—Select when using automatic backup. Selecting Delay is the same as selecting Std except that when an
FrcOn—When Forced On is selected, CTS remains ON as long as the DSU is receiving power.
(not displayed when a TDM/Flex is installed and enabled). Selects the active DTE interface.
19.2 kbps or below. Operation at speeds up to 56 kbps is dependent upon cable length, cable quality, and
the local environment.
feet.
. This configuration option determines how the DSU will function with respect to the RTS lead. If
idle (DMI), regardless of whether RTS at the DTE interface is ON or Off.
whenever RTS is Off, and a data mode idle (DMI) signal when RTS is ON.
. Controls the behavior of the CTS lead when abnormal conditions are present (e.g., No Signal or
abnormal conditions. When selected, CTS follows RTS except when the DSU is in Test Mode, or an
alarm or CMI is being received, and
alarm is received, CTS does not go low (drop) until the DBM or
time allotted by the
the Backup option set) is enabled.
Tries Time-Out
Circ Assur
(in the Backup options set) setting. Make sure that
is set to Enab.
external
DBU has failed to backup in the
Auto Backup
(in
AntiStream:Disab
Next Chang Prev
Antistreaming
circuit protection against a streaming DTE (a defective DTE that has its RTS lead constantly turned ON) by clamping the
RTS lead of the tributary DSU.
Antistreaming only takes effect when
Chang —Set timer to any value from 1 to 100 second(s), in increments of 1; or to Disab when streaming terminal
(only displayed when Full Mode is enabled, and a TDM/Flex is not installed). Antistreaming provides
RTS Cntrl
detection is not needed.
is set to DTE; it is disabled when
RTS Cntrl
is set to FrcOn.
5-173550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
LSD Lead: Std
Next Std Delay FrcOn Prev
Table 5-8
(2 of 4)
General Configuration Options
Line Signal Detect Lead
Std—Select standard so that the LSD lead goes Off when a control mode idle (CMI) signal is received from the
Delay—Select only if you do not want the DSU to respond to a network alarm condition or CMI signal. When
FrcOn—Select to keep LSD on as long as the DSU has power.
DSR FrcOn: Enab
Next Enab Disab Prev
DDS network, or there is a DDS failure.
selected, LSD only goes Off after repeated call attempts fail, and the period of time set in
(in the Backup option set) expires. Make sure that
Data Set Ready Forced On
ability to override any other options controlling the DSR lead.
Enab—Select for DSR to remain ON as long as the device is working, regardless of any tests or network alarms.
Disab—Select if DSR is to function as an active lead, reflecting various test and alarm conditions.
SystemStat: Enab
Next Enab Disab Prev
System Status
Signal, Out-of-Service, or Out-of-Frame alarm from the network.
Enab—Select if a network alarm is to turn DSR Off.
Disab—Select if a Model 3551 DSU with a V.32 DBM that is configured with its
(only displayed when Full Mode is enabled). Controls the behavior of the DSR lead in response to a No
set to Yes (DBM option set) is part of your network configuration. When selected, a network alarm will not
affect DSR.
(only displayed when Full Mode is enabled). Controls behavior of the LSD lead.
Tries Time-out
Auto Backup
(only displayed when Full Mode is enabled, and a TDM/Flex is not installed). Provides the
(in the Backup option set) is enabled.
Primary Core
configuration option
DSR on Tst: Enab
Next Enab Disab Prev
Data Set Ready On in Test
behavior of the DSR lead during testing.
Enab—Select so that DSR is ON continuously during testing, allowing a DTE that relies on DSR being ON to
Disab—Select so that DSR is Off during testing.
Circ Assur:Disab
Next Enab Disab Prev
Circuit Assurance
CTS lead in response to a data signal from the network. If CTS Cntrl is set to =RTS or FrcOn, this configuration option is
ignored.
Enab—Select to have the DSU turn Off the CTS lead if a control mode idle (CMI) signal is received.
Disab—Select if the DSU is to be unaffected by the CMI.
RespondRDL:Disab for MPTC; Enab for all other configurations
Next Enab Disab Prev
send test messages to the DSU.
(only displayed when LinkConfig is set to Pt-Pt and Full Mode is enabled). Controls behavior of the
Respond to Remote Digital Loopback
responds to a V.54 Remote Loopback request.
Enab—Select to perform a Digital Loopback.
Disab—Select to ignore the Loopback command.
(only displayed when Full Mode is enabled, and a TDM/Flex is not installed). Controls the
(only displayed when Full Mode is enabled). Determines whether the DSU
5-18February 19953550-A2-GB20-10
LL by DTE: Disab
Next Enab Disab Prev
Configuring the Unit
Table 5-8
(3 of 4)
General Configuration Options
Local Loopback by DTE
interface or Pin L of the V.35interface by the DTE to initiate a Local Loopback when the DSU is the active device.
Whenever this lead is ON, the Local Loopback overrides any other diagnostic tests run by the network.
Enab—Select if the DTE is to signal the DSU to perform a Local Loopback. Local Loopback ends when the
signal is dropped.
Disab—Select if Local Loopback requests are to be ignored.
RL by DTE: Disab
Next Enab Disab Prev
Remote Digital Loopback by DTE
Digital Loopback via Pin 21 of the EIA-232-D/V.24 interface or Pin N of the V.35 interface.
Enab—Select if the DTE is to force the DSU to request a Remote Digital Loopback when the signal is turned ON.
Remote Digital Loopback ends when the signal is dropped.
Disab—Select if the DSU is to ignore requests for a Remote Digital Loopback.
Bilat Lpbk:Disab
Next Enab Disab Prev
Bilateral Loopback
occurs when a Digital Loopback occurs.
Enab—Select for a DTE Loopback to be run whenever a Digital Loopback occurs.
Disab—Select for the DSU to ignore requests for a Bilateral Loopback.
Ext Leads: Rate
Next ExtLd Rate RPowr Prev
(only displayed when Full Mode is enabled). Controls the use of Pin 18 of the EIA-232-D/V.24
(only displayed when Full Mode is enabled). Allows the DTE to initiate a Remote
(only displayed when Full Mode is enabled). If this configuration option is enabled, a DTE Loopback
External Leads
EIA-232-D/V.24 interface for Port 1, except when Rate is selected. These leads can be controlled and monitored from
the DCP or from a 6700 Series NMS.
ExtLd—Select to enable Pin 12 and 13 as output (control) and Pins 19 and 23 as input (alarm) leads. When
Rate—Select if a TDM/Flex is installed, so that Pin 12 on each port can be used to control speed selection and
RPowr —Select only when a redundant power supply is installed in the COMSPHEREr 3000 Series Carrier. This
CCN by EL: Disab
Next Enab Disab Prev
Configuration Change Notification by External Leads
general-purpose output leads to set a CCN event.
Enab—Select if a change in state of a general-purpose lead signals CCN to the NMS.
Disab—Select if changes to the lead state do not set a CCN event.
(only displayed when Full Mode is enabled). Controls the use of the general-purpose leads on the
enabled, Pins 12 and 13 output +12V when ON and –12V when Off. Pins 19 and 23 recognize voltages
from +2.2V to +12V as ON (reported as an external alarm) and –12V to +.8V as Off.
cause an extended modem to change speed to match the backup port speed.
selection functions similarly to ExtLd.
(only displayed when Full Mode is enabled). Controls the use of the
Ext Leads
must be set to ExtLd.
5-193550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
DTR Alarm: Disab
Next Enab Disab Prev
Table 5-8
(4 of 4)
General Configuration Options
Data Terminal Ready Alarm
DSU to generate an alarm if DTR is Off for more than 30 seconds. The DCP displays
to the NMS.
Enab—Select if the DSU should generate an alarm when DTR is turned Off for 30 seconds.
Disab—Select if the DTR lead is to be ignored.
Async→Sync: Disab
Next Enab Disab Prev
Asynchronous-to-Synchronous Conversion
asynchronous or synchronous operation.
Enab—Select to configure the DSU as asynchronous. An asynchronous-to-synchronous conversion takes place.
Disab—Select to configure the DSU as synchronous.
AsyncBit/Char: 8
Next 6 7 8 9 10 Prev
Asynchronous Bits per Character
including the parity bit but excluding the start and stop bits. This configuration option only applies when
enabled.
6 to 10 —Select the number of asynchronous bits per character. When
Stop Bits: 1
Next 1 2 Prev
Stop Bits
This configuration option only applies when
1 to 2 —Select the number of stop bits to be used. When the
displayed.
(only displayed with no TDM/Flex installed). Specifies the number of stop bits in an asynchronous character.
not be displayed.
(only displayed when Full Mode is enabled, and a TDM/Flex is not installed). Causes the
(only displayed with no TDM/Flex installed). Sets Port 1 of the DSU for
(only displayed with no TDM/Flex installed). Specifies the length of a character,
DTR Alarm
and reports the alarm
Async→Sync
Async→Sync
Stop Bits
is enabled.
AsyncBit/Char
is set to 2, 10 will not be
configuration option is set to 10, 2 will
is
Overspeed: 2.3
Next 1.0 2.3 Prev
Overspeed
asynchronous-to-synchronous converter. This configuration option only applies when
1.0—Select the basic overspeed range.
2.3—Select the overspeed percentage for extended range.
5-20February 19953550-A2-GB20-10
(only displayed with no TDM/Flex installed). Selects the overspeed range of the
Async→Sync
Basic range
rate.
DTE asynchronous data rate.
provides 1.0% overspeed in the DTE asynchronous data
Extended range
provides 2.3% overspeed in the
is enabled.
Auto Bckup:Disab
Next Enab Disab Prev
Configuring the Unit
Table 5-9
(1 of 2)
Backup Configuration Options
Automatic Backup
Controls automatic initiation of a call setup attempt to a remote DBM or modem when there is a failure of the DDS
network. (Automatic dial attempts begin after the Network Time-out expires.)
Enab—Select to initiate backup when there is a failure of the DDS network. The DSU waits for a period equal to
Disab—Select so that no automatic dial backup connections are attempted.
Backup Dir: 1
Next Chang Prev
Backup Directory
identified by the numbers 1 through 10. Selecting the Backup Directory identifier displays the telephone number stored in
that directory .
Chang —Select to enter or change the telephone number that is displayed.
FacAlOnCMI:Disab
Next Enab Disab Prev
Facility Alarm on Control Mode Idle
DBU is configured to originate backup). Determines whether the DSU treats a control mode idle (CMI) condition as a
facility alarm to trigger automatic dial backup. Configuration option
FrcOn.
Enab—Select if the DSU should try and attempt to establish a dial backup connection to a remote DSU after the
Disab—Select if a dial backup connection should not be attempted when CMI is detected.
(only displayed when a DBM is installed, or an external DBU is configured to originate backup).
DDS Time-out, and if the DDS network is still down, it attempts to establish a dial backup connection to
the remote DBM.
(only displayed when a DBM is installed). The DBM can store 10 telephone numbers or dial strings,
Network Time-out.
(only displayed when Full Mode is enabled, when a DBM is installed, or an
Auto Bckup
must be enabled, and
RTS Cntrl
external
set to
AutoRestor:Disab
Next Enab Disab Prev
Automatic Restoration
returned to service.
On point-to-point circuits, a Digital Test is run to verify the DDS network. If the Digital Test is successful, user data is
switched back to the DDS circuit.
For a multipoint network with dedicated multipoint dial backup, each tributary may be configured for
not occur unless backup was initiated by the tributary. The DDS network is not verified before data is switched back to
the DDS network.
Enab—Select if restoral of the DDS circuit should trigger automatic restoration (after the Restoration Time-out
Disab—Select if restoral of the DDS circuit is not to trigger automatic restoration.
NtwkTimOut: 0:20 for a control DSU; 01:00 for a tributary DSU
Next Chang Prev
Network Time-out
remain out of service before the dial backup call attempt sequence is made. (
. Controls whether the DSU automatically terminates the dial backup call when the DDS circuit has
Auto Restor
expires).
(only displayed when Full Mode is enabled). Specifies the length of time the DDS network must
Auto Bckup
must be enabled.)
, but will
When
configured for nondisruptive diagnostics, rate adaption, or if TDM/Flex is enabled, this configuration option must be set to
greater than or equal to 20 seconds.
Chang —Select to enter or change the current settings, which can range from 1 second to 30minutes. The cursor
has two positions: a minutes field with a range of 0 to 29, and a seconds field with a range of 00 to 59.
5-213550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
RestorTimOut: 5m
Next Chang Prev
Table 5-9
(2 of 2)
Backup Configuration Options
Restoration Time-out
back in service before automatic restoration is attempted. (
Chang —Select to enter or change the current setting (range of 1 to 60 minutes).
TriesTimeOut:15m
Next Chang Prev
Call Attempts Time-out
attempts when the DDS network fails.
calling cycle) or disabled (normal calling cycle).
Only 10 call attempts are made for the normal calling cycle. If a call attempt is in progress and the timer expires, the call
attempt will
Chang —Select to enter or change the current setting (range of 1 to 60 minutes).
MultiCall:Disab
Next Enab Disab Prev
Multiple Calls
backup, this configuration option selects the multiple calling cycle in which the DBM steps through the Backup Directory ,
attempting to call each valid telephone number in the directory , or selects the normal calling cycle. This configuration
option only has an effect if
Enab—Select if the multiple calling cycle is to be used. The DBM makes one attempt to call the telephone
Disab—Select if the normal calling cycle is to be used: three call attempts, a 5-minute wait, three more call
NOTE: Multicall must not be enabled unless successive telephone numbers in the Backup Directory are different. In
not
(only displayed when Full Mode is enabled and a DBM is installed). Used primarily for multipoint dial
addition, duplicate telephone numbers should be avoided. These precautions prevent the DBM from making
excessive call attempts to the same telephone number.
(only displayed when Full Mode is enabled). Specifies the length of time the DDS network must be
(only displayed when Full Mode is enabled). Sets an overall time limit for dial backup call
be aborted.
Auto Bckup
number in the specified Backup Directory (default is the first telephone number in the directory). If the
attempt fails, the DBM makes an attempt to call the next telephone number in the specified directory , and
so on until either a call is completed or the DBM cycles through all the telephone numbers in the Backup
Directory, ignoring blank entries. The DBM then waits five minutes and begins the calling cycle again until
TriesTimeOut
the
attempts, another 5-minute wait, etc., until the
Auto Bckup
is set to Enab.
period expires.
must be enabled, regardless of whether
Auto Restor
T riesTimeOut
must be enabled.)
period expires.
MultiCall
is enabled (multiple
5-22February 19953550-A2-GB20-10
Table 5-10
MUX (Setup) Configuration Options
MUX Funct: Disab for MPTC; Enab for all other configurations
Next Enab Disab Prev
Configuring the Unit
TDM/Flex Function
Enab—Select when you want to enable the TDM/Flex and perform multiplexing.
Disab—Select when you want to disable the TDM/Flex.
Share DevA: Enab MPTT; Disab for all other configurations
Next Enab Disab Prev
Sharing Device A
apply:
• All ports in a group must have the same port speed.
• All ports must be adjacent.
. Enables or disables the TDM/Flex.
. Enabling this configuration option allows you to create a digital-sharing group. The following rules
• A digital-sharing group can have 2 ports.
Enab—Select to enable the digital-sharing feature.
Disab—Select to disable the digital-sharing feature.
Port Cntrl: DSD for MPTT; Host for all other configurations
Next Host DSD Prev
Port Control
Host—Select if the Host protocol must enforce the order of transmission to avoid collisions.
DSD—Select for Digital-Sharing Device if selection of the next port to transmit is based upon the
. Specifies how to handle contention between the ports in a digital-sharing group.
lowest-numbered port that is ready to transmit.
Table 5-11
(1 of 4)
MUX (Port) Configuration Options*
DTE Port: EIA232
Next EIA232 V.35 Prev
DTE Port
EIA232 —Select when using the EIA-232 interface/connector.
V.35—Select when using the V.35 interface/connector (a V .35 Interconnect Cable must be used on Port 2).
Async→Sync: Disab
Next Enab Disab Prev
Asynchronous-to-Synchronous Conversion
Option Verification: When the TDM/Flex is enabled, the DSU verifies that the sum of the port speeds equals the
aggregate speed. The asynchronous setting
Enab—Select to configure the port as asynchronous (asynchronous-to-synchronous conversion takes place).
Disab—Select to configure the port as synchronous.
. Selects the port data will be transmitted over.
. Sets the port for asynchronous or synchronous operation.
the synchronous data rate of the port. Set the synchronous data rate for a port via the Port Speed (PrtSp) configuration
submenu. This configuration option is displayed only if
Option Verification: When 1800 bps is selected, the DSU verifies that the synchronous port speed is 2400 bps or
greater. If only one stop bit is used, the asynchronous rate
=Sync—Select for the asynchronous rate to be the same as the synchronous rate.
. Specifies the rate of an asynchronous port. The asynchronous rate must be
Async→Sync
cannot
is enabled.
be equal to half the synchronous rate.
less than
or
equal to
1800—Select the rate of the asynchronous port.
to 150
AsyncBit/Char: 8
Next 6 7 8 9 10 Prev
Asynchronous Bits per Character
stop bits. This configuration option is displayed only if
option only displays 1.
6 to 10 —Select the asynchronous bits per character.
Stop Bits: 1
Next 1 2 Prev
Stop Bits
the
only 1 stop bit appears.
1 to 2—Select the number of stop bits to be used.
Overspeed: 2.5
Next 1.25 2.5 Prev
. Specifies the number of stop bits in an asynchronous character. This configuration option is displayed only if
Async→Sync
configuration option is enabled and
. Specifies the length of a character, including the parity bit but excluding the start and
Async→Sync
AsyncBit/Char
is enabled. If set to 10, the
is set to 6, 7, 8, or 9. If
AsyncBit/Char
Stop Bits
configuration
is set to 10,
Overspeed
applies when
1.25—Select the basic overspeed range.
2.5—Select the overspeed percentage for extended range.
RTS Cntrl: DTE
Next FrcOn DTE Prev
Request-to-Send Control
FrcOn—Select for the DSU to keep the internal RTS ON continuously. Any data appearing on the transmitted data
DTE—Select for the DSU to turn ON RTS when the external RTS is turned ON. CTS is turned ON or Off by the
. Selects the overspeed range of the asynchronous-to-synchronous converter. This configuration option only
Async→Sync
rate.
DTE asynchronous data rate.
(TXD) lead from the DTE is transmitted immediately .
external control signal RTS.
is enabled.
Basic range
provides 1.25% overspeed in the DTE asynchronous data
Extended range
. Controls the behavior of the internal RTS lead.
provides 2.5% overspeed in the
* The menu paths for Prt1 and Prt2 are identical.
5-24February 19953550-A2-GB20-10
TxCarrSel: Const
Next Const Cntrl Prev
Configuring the Unit
Table 5-11
(3 of 4)
MUX (Port) Configuration Options*
Transmitter Carrier Select
simulate switched-carrier operation (using the V.13 codes) on an individual channel. Simulated switched-carrier
operation is also referred to as pseudo-controlled carrier (PCC) mode. It is required for applications where the receiving
DTE expects a raised LSD lead prior to receiving data.
NOTE: A port may be configured for switched-carrier operation in one direction and constant-carrier operation in the
other.
Const—Select (constant-carrier operation) if the V.13 codes are not to be sent. The corresponding remote
TDM/Flex port must be configured for Receiver Constant Carrier or Mark (
Mark). Configure each port in a digital-sharing group for Constant Carrier operation (
Const).
Cntrl—Select Controlled or switched-carrier operation (PCC mode) if the DSU is to transmit the V.13 codes over
the DDS line when the port RTS changes state. When RTS is turned ON, the DSU transmits a code that
turns ON LSD at the remote TDM/Flex port before CTS is turned ON at the local port. When RTS is
dropped, the DSU sends a code that turns Off LSD at the remote TDM/Flex port. The corresponding
remote TDM/Flex port must be configured for Receiver Controlled Carrier (
selection is not valid if the DSU is part of a Digital-Sharing Device (DSD) group. (See the Mark selection
in the configuration option Receiver Carrier Select.)
RxCarrSel: Const
Next Const Cntrl Mark Prev
Receiver Carrier Select
switched-carrier operation (using the V.13 codes) on an individual circuit.
NOTE: Configuration values Const and Cntrl for Receiver Carrier Select are both valid choices for a port belonging to a
digital-sharing group.
Const—Select Constant-carrier operation if the receiving DSU is not to look for V.13 codes used by the V.13
protocol, and is not to toggle LSD.
Cntrl—Select Controlled or switched-carrier operation (PCC mode) if the receiving DSU is to look for V.13 codes
used by the V.13 protocol indicating the transition of RTS at the remote TDM/Flex port; the receiving DSU
toggles LSD as appropriate.
Mark—Select if 30 consecutive Marks are received and received Line Signal Detect (LSD) goes Off at the port.
Received LSD goes ON again just before the first space. (
unit.)
PCC Buffer: Disab
Next Enab Disab Prev
(only displayed when Full Mode is enabled). Enables the TDM/Flex transmitter circuitry to
RxCarrSel
RxCarrSel
(only displayed when Full Mode is enabled). Enables the TDM/Flex receiver circuitry to simulate
TxCarrSel
must be set to Const at the remote
set to Const or
TxCarrSel
set to Cntrl). This
set to
This setting is used primarily when the remote DSU has a DSD group.
Pseudo-Controlled Carrier Buffer
V.13 protocol so they do not pass to the receiving DTE. This configuration option is only valid when
Cntrl.
For an asynchronous port configured for switched-carrier operation, set
For a synchronous port configured for switched-carrier operation,
whether the V.13 codes disrupt communication at the receiving DTE.
(only displayed when Full Mode is enabled). Intercepts the V.13 codes used by the
PCC Buffer
PCC Buffer
to Enab.
can be disabled or enabled, depending on
Be aware that enabling this configuration option
can corrupt the end-of-message for some synchronous protocols.
Enab—Select to enable the PCC Buffer feature.
Disab—Select to disable the PCC Buffer feature.
* The menu paths for Prt1 and Prt2 are identical.
RxCarrSel
is set to
5-253550-A2-GB20-10February 1995
COMSPHERE 3550 Series Data Service Units
Elast Stor: Disab
Next Enab Disab Prev
Table 5-11
(4 of 4)
MUX (Port) Configuration Options*
Elastic Store
Serial data from the extended circuit is clocked into the DSU elastic store using a clock provided by the extended circuit
received clock lead. The DSU uses its own system timing to clock data out of the buffer.
Elastic Store is reset on power-up, overflow, or after the RTS lead makes an Off-to-ON transition. After reset, the elastic
store can drift by ±5 bits with the TDM/Flex enabled before overflow occurs.
Enab—Select to enable this configuration option.
Disab—Select to disable this configuration option.
RTS/CTS Del: 0
Next Chang Prev
Request-To-Send to Clear-To-Send Delay
between the time that RTS is turned ON and CTS is turned ON. An additional delay is sometimes required for
multiplexed applications operating in switched-carrier operation.
(only displayed when Full Mode is enabled). Elastic Store hardware consists of a transmit buffer (register).
(only displayed when Full Mode is enabled). Allows for an additional delay
Enough delay must be provided so that the last DSU in
the circuit has time to train and is ready to accept data before CTS is turned ON.
Chang —Select to change the RTS-to-CTS delay, from 0 to 1040 milliseconds in 8 milliseconds increments.
DTR Alarm: Disab
Next Enab Disab Prev
Data Terminal Ready Alarm
if the port’s DTR lead is Off for more than 30 seconds. The DCP displays DTR Alarm and reports the alarm to NMS.
Enab—Select if you want the DSU to report an alarm when the port’s DTR lead turns Off for 30 seconds.
Disab—Select if no alarm is to be reported, regardless how long the port’s DTR lead is Off.
AntiStream:Disab
Next Chang Prev
(only displayed when Full Mode is enabled). Causes the DSU to report an alarm for the port
Antistreaming
DTE (a defective DTE that has its RTS lead constantly turned ON) by clamping the RTS lead of the tributary DSU.
Antistreaming only takes effect when
Chang —Set timer to any value from 1 to 100 second(s), in increments of 1; or to
DSR FrcOn: Enab
Next Enab Disab Prev
Data Set Ready Forced On
options controlling the DSR lead.
Enab—Select for DSR to remain ON as long as the device is working, regardless of any tests or network alarms.
Disab—Select if DSR is to function as an active lead, reflecting various test and alarm conditions.
DSR on Tst: Enab
Next Enab Disab Prev
Data Set Ready On in Test
testing.
Enab—DSR is ON continuously during testing, allowing a DTE that relies on DSR being ON to send test
Disab—DSR is Off during testing.
(only displayed when Full Mode is enabled). Antistreaming provides circuit protection against a streaming
RTS Cntrl
detection is not needed.
(only displayed when Full Mode is enabled). Provides the ability to override any other
(only displayed when Full Mode is enabled). Controls the behavior of the DSR lead during
1.2 kbps
Disab—Select to disable the port.
Option Verification: For all ports, the DSU verifies that the sum of the individual port speeds does not exceed the
1.2 kbps
Disab—Select to disable the port.
Option Verification: For all ports, the DSU verifies that the sum of the individual port speeds does not exceed the
primary aggregate speed set in
aggregate rate,
Underspeed: Disab
Next Disab Prt1 Prt2 Prev
Underspeed Port
channel transport, if used. If more than one port is active and the sum of the port speeds equals the primary aggregate
speed,
The number of bits per second used for in-band framing is 10. The in-band secondary channel transport speed is set in
2nd Chan(bps)
for underspeed.
NOTE: When
Disab—No port runs underspeed during primary operation.
Prt1 or —Selected port runs underspeed during primary operation.
Prt2
. Primary data rate in kbps on Port 1. (Must be set to the same value in the remote DSU.)
an underspeed port selection is required
Rate(Kbps)
. Primary data rate in kbps on Port 2. (Must be set to the same value in the remote DSU.)
Rate(Kbps)
an underspeed port selection is required
. Selects which port is to run slightly underspeed to allow for in-band framing and in-band secondary
then one synchronous port must run underspeed
and, if used, includes the 10 bps in-band framing. A port used for asynchronous operation may not be set
Port Cntrl
counted once per DSD when calculating used bandwidth.
is set to DSD or
in the DSU option set. If the sum of the port speeds
in the DSU option set. If the sum of the port speeds
Share DevA
.
.
.
is enabled (in the MUX (Setup) option set), port speeds are only
1.2 kbps
Disab—Select to disable the port.
Option Verification: For all ports, the DBM verifies that the sum of the individual port speeds does not exceed the
primary aggregate speed set in
aggregate rate,
Prt2( 9.6): 9.6 for MPTT; Disab for all other configurations
Next 14.4 12.0 19.2 9.6 4.8 2.4 1.2 Disab Prev
Port 2 Speed
14.4 to —Select to set the port’s operating rate.
1.2 kbps
Disab—Select to disable the port.
Option Verification: For all ports, the DSU verifies that the sum of the individual port speeds does not exceed the
primary aggregate speed set in
aggregate rate,
Underspeed: Disab
Next Disab Prt1 Prt2 Prev
Underspeed Port
channel transport, if used. If more than one port is active and the sum of the port speeds equals the primary aggregate
speed,
The number of bits per second used for in-band framing is 10. The in-band secondary channel transport speed is set in
2nd Chan(bps)
for underspeed.
NOTE: When
Disab—No port runs underspeed during primary operation.
Prt1 or —Selected port runs underspeed during primary operation.
Prt2
. Primary data rate in kbps on Port 1. (Must be set to the same value in the remote DBM.)
an underspeed port selection is required
Rate(Kbps)
. Primary data rate in kbps on Port 2. (Must be set to the same value in the remote DBM.)
Rate(Kbps)
in the DBM option set. If the sum of the port speeds
.
in the DBM option set. If the sum of the port speeds
an underspeed port selection is required.
. Selects which port is to run slightly underspeed to allow for in-band framing and in-band secondary
then one synchronous port must run underspeed
and, if used, includes the 10 bps in-band framing. A port used for asynchronous operation may not be set
Port Cntrl
counted once per DSD when calculating used bandwidth.
is set to DSD or
Share DevA
.
is enabled (in the MUX (Setup) option set), port speeds are only
1.2 kbps
Disab—Select to disable the port.
Option Verification: For all ports, the DSU verifies that the sum of the individual port speeds does not exceed the
primary aggregate speed set in the
the primary aggregate rate,
1.2 kbps
Disab—Select to disable the port.
Option Verification: For all ports, the DSU verifies that the sum of the individual port speeds does not exceed the
primary aggregate speed set in the
the primary aggregate rate,
Underspeed: Disab
Next Disab Prt1 Prt2 Prev
Underspeed Port
channel transport, if used. If more than one port is active and the sum of the port speeds equals the primary aggregate
speed,
The number of bits per second used for in-band framing is 10. The in-band secondary channel transport speed is set in
2nd Chan(bps)
for underspeed.
NOTE: When
Disab—Select if no port is to run underspeed during primary operation.
Prt1 or —Select the port to run underspeed during primary operation.
Prt2
. Primary data rate in kbps on Port 1. (Must be set to the same value in the
an underspeed port selection is required
external
. Primary data rate in kbps on Port 2. (Must be set to the same value in the
external
DBU’s
DBU’s
Rate(Kbps)
Rate(Kbps)
configuration option. If the sum of the port speeds equals
.
configuration option. If the sum of the port speeds equals
an underspeed port selection is required.
. Selects which port is to run slightly underspeed to allow for in-band framing and in-band secondary
then one synchronous port must run underspeed
and, if used, includes the 10 bps in-band framing. A port used for asynchronous operation may not be set
Port Cntrl
counted once per DSD when calculating used bandwidth.
This menu is your map through the DSU’s various
functions and pathways. Compare it against the menus
that appear as you move through procedures. You will
learn to quickly access where you want to go on the menu
when operating the DSU. (This menu is also included on
the Reference Card that comes with this guide, which can
be removed and placed with your DSU.)
Menu Structure
The DSU’s operation is represented as menu selections
that branch downward from its starting point, the top-level
menu, like the roots of a tree. The menu is sometimes
referred to as a menu tree.
Top-Level Menu
The top-level menu is the starting point for all DSU
operations. You can always return to this point from
anywhere in the menu by pressing the
this key immediately terminates any operation or work in
progress.
key. Pressing
The following shows an example of the top-level menu
for a standalone Model 3550 DSU that is configured as a
control operating at 9.6 kbps, with an NMS message
waiting.
Port1 DSU 9.6 C
Local Remot Msg
F1
The following information is displayed:
Line 1 – Source of the information being displayed
–DSU’s current function or mode (In this
example, the unit is operating as a DSU,
not as a DBM or TDM/Flex.)
–DSU’s data rate
–DSU’s network designation (Here the
DSU is a control.)
If this display was for a Model 3551 (a
carrier-mounted DSU), the carrier (nest or
rack) and slot numbers would appear
instead of Port 1 (e.g., Carrier 2 and
Slot 16 would appear as 2:16).
F2
F3
Line 2 – Menu selections, one appearing directly
over each function key (F1 and F2).
Continued on Page A-4.
A-13550-A2-GB20-10February 1995
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