®
ONline Ethernet 10BASE-T
Module
User’s Guide
Document Number 17-00141-3
Printed March 1995
Model Number: 5108M-TP
3Com Corporation
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Southborough, MA 01772-1886
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ONline Ethernet 10BASE-T Module User’s Guide iii
iv ONline Ethernet 10BASE-T Module User’s Guide
Contents
How to Use This Guide
Audience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xiii
Structure of This Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xiv
Document Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv
Related Documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xvi
3Com Documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvii
Reference Documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvii
Chapter 1 — Introduction
The ONline Ethernet 10BASE-T Module . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Dip Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
Dip Switch SW1 (Port Status) . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
Dip Switch SW3 (Crossover Mode, Channel Select, Squelch) . . . . 1-6
Dip Switch SW6 (Link Integrity) . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
Related Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
LED and Channel Verification . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
The ONline Ethernet Network Management Module . . . . . . . . . 1-11
Chapter 2 — Designing and Expanding the Netw ork
Understanding the General Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Basic Network Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
LAN Equivalence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
Fiber Backbone, Twisted Pair To-The-Desk . . . . . . . . . . . . . . . . . . . . . . . 2-7
Fiber Backbone, Twisted Pair To-The-Desk Example . . . . . . . . . . . 2-8
Twisted Pair Backbone, Twisted Pair To-The-Desk . . . . . . . . . . . . . . . . . 2-11
Redundant Links . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12
Patch Panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14
ONline Ethernet 10BASE-T Module User’s Guide v
Chapter 3 — Installing and Operating the Module
Precautionary Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Unpacking Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
Installation Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
Chapter 4 — Troubleshooting
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
Troubleshooting With the Status LEDs . . . . . . . . . . . . . . . . . . . . . . . 4-1
Troubleshooting With the Activity LEDs . . . . . . . . . . . . . . . . . . . . . . 4-5
Technical Assistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
Appendix A — Specifications
ONline Ethernet 10BASE-T Module Specifications . . . . . . . . . . . . . . . . . . A-1
Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1
Environmental Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2
Mechanical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2
General Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2
Twisted Pair Connectors and Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3
Twisted Pair Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3
Twisted Pair Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-4
Connecting Twisted Pair Cables . . . . . . . . . . . . . . . . . . . . . . . . . A-5
Appendix B — Technical Support
On-line Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1
Email Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2
World Wide Web Site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2
Support from Your Network Supplier . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2
Support from 3Com . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-3
Returning Products for Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-4
Accessing the 3Com MIB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-4
3Com Technical Publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-5
Index
vi ONline Ethernet 10BASE-T Module User’s Guide
Figures
Figure 1-1.
10BASE-T Module Faceplate and ONline
System Concentrator . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Figure 1-2.
Figure 2-1.
Figure 2-2.
Figure 2-3.
Figure 3-1.
Figure 3-2.
Figure A-1.
10BASE-T Module and Dip Switch Locations . . . . . . . . . . 1-5
Sample Configuration Distance Calculation . . . . . . . . . . . 2-9
Unshielded Twisted Pair Network . . . . . . . . . . . . . . . . . 2-11
Redundant Twisted Pair Configuration . . . . . . . . . . . . . 2-12
Installing a 10BASE-T Module . . . . . . . . . . . . . . . . . . . . . 3-3
10BASE-T Module Cable Connection . . . . . . . . . . . . . . . 3-4
RJ45 Connector Pin-outs . . . . . . . . . . . . . . . . . . . . . . . . . A-4
ONline Ethernet 10BASE-T Module User’s Guide vii
viii ONline Ethernet 10BASE-T Module User’s Guide
Tables
Table 1-1.
Interpretation of the 10BASE-T Module LEDs . . . . . . . . . . 1-4
Dip Switch SW1 Settings and Interpretations . . . . . . . . . . 1-6
Dip Switch SW3 Settings for Switches 1 and 4 . . . . . . . . . 1-7
Table 1-2.
Table 1-3.
Table 1-4.
Dip Switch SW3 Settings and Interpretations for
Switches 2 and 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
Table 1-5.
Table 1-6.
Table 2-1.
Table 2-2.
Table 2-3.
Table 4-1.
Table 4-2.
Dip Switch SW6 Settings and Interpretations . . . . . . . . . 1-10
Channel Check Codes . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11
Seven Basic Network Rules. . . . . . . . . . . . . . . . . . . . . . . . 2-3
LAN Product Equivalent Distances . . . . . . . . . . . . . . . . . . 2-6
Maximum Link Distance on Twisted Pair. . . . . . . . . . . . . 2-10
Troubleshooting With the Port Status LEDs . . . . . . . . . . . 4-2
Troubleshooting With the Port Activity LEDs. . . . . . . . . . . 4-5
ONline Ethernet 10BASE-T Module User’s Guide ix
How to Use This Guide
The ONline™ Ethernet 10BASE-T Module User’s Guide describes the
features, indicators, and installation procedures for the ONline Ethernet
10BASE-T Module. Information on troubleshooting and diagnostics is
included for verifying operation. This guide also contains a configuration
section which will be helpful when you plan your network configuration.
Audience
This guide is intended for the following people at your site:
❑ Network manager or administrator
❑ Hardware installer
ONline Ethernet 10BASE-T Module User’s Guide xi
Structure of This Guide
This guide contains the following chapters:
Cha pte r 1, Introductio n –Introduces the principal features of the ONline
Ethernet 10BASE-TModule and providesviews and descriptions of the front
panel and the dip switches on the module.
Cha pte r 2, Designing and Expa nding th e Netw ork – Shows and
explains examples of possible network configurations using the ONline
System Concentrator and the ONline Ethernet 10BASE-T Module. These
examples include both shielded and unshielded twisted pair configurations.
Cha pte r 3, Installing a nd Ope ra ting the Module – Providesillustrated
procedures for installing the 10BASE-T Module into the ONline System
Concentrator.
Cha pte r 4, Tro ubleshootin g –Provides help in isolating and correcting
problems that mayarise during the installation process and during normal
operation.
Appe ndix A, Specificatio ns – Provides electrical, environmental, and
mechanical specifications, as well as other information for the module.
Appendix B, Technical Support – Lists the various methods for
contacting the 3Com technical support organization and for accessing
other product support services.
Index
xii ONline Ethernet 10BASE-T Module User’s Guide
Document Conventions
The following document conventions are used in this manual:
Convention
Courier text
Indicates
User input
Example
In the Agent Information Form,
enter MISin the New Contact
field.
System output
Path names
After pressing the Apply
button, the system displays
the message
Transmitting data.
Bold command
string
Before you begin, read the
readme.txt file located in
/usr/snm/agents.
Italic text in braces User-substituted Use the following command to
identifiers
show port details:
SHOW PORT {slot.all} VERBOSE
Capitalized text in
plain brackets
Keyboard entry Type your password and press
by the user
[ENTER].
Italics
Text emphasis,
Ensure that you press the Apply
document titles button after you add the new
search parameters.
ONline Ethernet 10BASE-T Module User’s Guide xiii
Convention
Note:
Indicates
Example
A Note. The
information is
important
Note: Use STP lobe
cables for your system.
Caution: A Caution. A
condition may
damage
Caution: Do not put
your installation
diskettes on a
software or
hardware
magnetic surface.
This may damage the
diskettes.
Warning: A Warning. A
condition may
Warning: Wear eye
protection when
performing these
maintenance
threaten
personal safety
procedures.
Related Documents
This section providesinformation on suppo rting documentation, including:
❑ 3Com Documents
❑ Reference Documents
xiv ONline Ethernet 10BASE-T Module User’s Guide
3Com Documents
The following documents provide additional information on 3Com
products:
17-Slot ONline System Concentrator Installation and Operation
Guide – Explains how to install, operate, and manage the 3Com ONline
17-Slot System Concentrator (Models 5017C-LS and 5017C with load
sharing).
6-Slot ONline System Concentrator Installation and Operation
Guide – Explains how to install, operate, and manage the 3Com ONline
6-Slot System Concentrator.
ONline Ethernet Management Module Installation and Operation Guide –
Describes how to install the ONline Ethernet Network Management
Module in the ONline System Concentrator and explains the LEDs on the
module faceplate. This guide also provides instructions for connecting a
terminal to the module and describes the management commands
necessary to perform management tasks on the concentrator and on
remote devices.
ONline Management Commands Guide – Provides an alphabetized
reference resource describing all ONline management commands.
For a complete list of 3Com documents, contact your 3Com representative.
Reference Documents
The following documents supply related background information:
Case, J., Fedor, M., Scoffstall, M., and J. Davin, The Simple Network
Management Protocol, RFC 1157, University of Tennessee at Knoxville,
Performance Systems International and the MIT Laboratory for Computer
Science, May 1990.
Rose, M., and K. McCloghrie, Structure and Identification of
Management Information for TCP/IP-based Internets, RFC 1155,
Performance Systems International and Hughes LAN Systems, May 1990.
ONline Ethernet 10BASE-T Module User’s Guide xv
Introduction
1
This chapter describes the features, indicators, and dip switch settings on
the ONline™ Ethernet 10BASE-T Module.
The ONline Ethernet 10BASE-T Module
The ONline™ Ethernet 10BASE-T Module is an eight-port IEEE 802.3
repeater module that complies with the 10BASE-T standard. This module
works with the 3Com ONline System Concentrator using both unshielded
and shielded twisted pairwiring. The ONline 10BASE-TModule providesthe
following features and benefits:
❑ supports up to 150 meter link distances on 22 gauge wire, up to 125
meters on 24 gauge wire, and up to 100 meters on 26 gauge wire
❑ supports up to 200 meter link distance on IBM Type 1 cabling
❑ complies fully with the 10BASE-T standard
❑ features “hot swap” capability so that you can install or remove the
module without having to power down the concentrator
The 10BASE-T Module works with both unshielded and shielded twisted
pair wire. A single module can support any mix of shielded and unshielded
twisted pair connections. For example, ports 1, 2, and 6 can be unshielded
Introduction 1 - 1
twisted pair connections while ports 3, 4, 5, and 7 are shielded twisted pair
connections.
In addition to complying with the 10BASE-T standard, each port provides
support for features that are beyond the scope of the 10BASE-T standard:
❑ supports shielded twisted pair cable
❑ allows Low Squelch level (which significantly increases achievable link
distances)
❑ allows Link Integrity to be disabled (which allows connection to some
equipment which does not conform to the 10BASE-T standard)
Before installing the Ethernet 10BASE-T Module, read the ONline System
Concentrator Installation and Operation Guide.
Indicators
The 10BASE-T Module has eight Activity and eight Status LEDs on the front
panel that indicate the state of each port on the module. Figure 1-1 shows
the locations of these indicators and Table 1-1 describes how to read them.
1 - 2 ONline Ethernet 10BASE-T Module User’s Guide
Figure 1-1. 10BASE-T Module Faceplate and ONline
System Concentrator
Introduction 1 - 3
Table 1-1. Interpretation of the 10BASE-T Module LEDs
LED Name
Color
State
Indicates
Activity
(Ports 1-8)
yellow Off
No packetsare received on
the segment.
On
Constant activity on the
segment.
Blinking
Normal activity on the
segment.
Status
green
Off
Port disabled.
(Ports 1-8)
On
Port enabled and Link
Integrity is functional.
1 blink
Link Integrity error.
2 blinks
Jabber error or port
partitioning.
Timed blinks (LED Link Integrity disabled for
is on for 10
this active port.
seconds, blinks
off for 400 msecs)
Dip Sw itches
The 10BASE-T Module has three dip switches located on the module:
❑ 8-switch dip switch (SW1)
❑ 4-switch dip switch (SW3)
❑ 8-switch dip switch (SW6)
1 - 4 ONline Ethernet 10BASE-T Module User’s Guide
Configure the switches to the settings you want if different than the
default values. (Refer to Table 1-2, Table 1-3, Table 1-4, and Table 1-5 for an
explanation of the dip switch settings.) Figure 1-2 shows the location of the
dip switches.
Figure 1-2. 10BASE-T Module and Dip Sw itch Locations
Dip Sw itch SW1 (Port Status)
The eight switches on dip switch SW1 allow you to enable or disable each
of the eight ports. The switches are labeled 1 through 8 and correspond to
the respective eight ports. The Off position disables the port and the On
position enables the port. The switch settings are initially configured in the
Introduction 1 - 5
On position, therefore, all ports are initially enabled. Table 1-2 describes the
settings and functions for switches 1 through 8.
Table 1-2. Dip Sw itch SW1 Settings and Interpretations
Factory
Default
Sw itch Setting
Sw itch
Function
Off
On
1 - 8
Enable/disable port
enable
disable
enable
If you have an ONline Ethernet Network Management Module installed in
your concentrator, you can remotely override these switch settings. Refer to
the ONline Ethernet Network Management Module Installation and
Operation Guide for information on remotely managing the ports.
Dip Sw itch SW3 (Crossover Mode, Channel Select, Squelch)
The four switches on dip switch SW3 allow you to:
❑ set port 8 to uncrossed mode
❑ select a channel for the module
❑ set the Squelch level to high (normal) or low (sensitive)
The switches are labeled 1 through 4 and the settings affect all eight ports.
Switch 1 allows you to enable or disable crossover mode for port 8. The
channel is initially configured for channel 1 (default) and Squelch level is
initially configured for high (default). The following sections explain the
crossover, channel selection, and Squelch mode.
If you have an ONline Ethernet Network Management Module installed in
your concentrator, you can remotely override these switch settings.
1 - 6 ONline Ethernet 10BASE-T Module User’s Guide
Table 1-3 explains crossover mode and squelch mode switch settings and
the sections following the table explain these features in more detail. The
channel selection switches are discussed in Table 1-4.
Table 1-3. Dip Sw itch SW3 Settings for Sw itches 1 and 4
Factory
Default
Sw itch Setting
Sw itch
Function
Off
On
1
Enable/disable
crossover mode for
port 8 only
enable
disable
(uncrossed) (crossed)
enable
4
Squelch mode
high
low
high
Crossover Mode Sw itch
All eight ports on the 10BASE-T Module are internally crossed over as per
10BASE-Tstandard. Thisenablesthe 10BASE-TModule to be connected to a
10BASE-T Transceiver. Port 8, however, can be uncrossed using the
crossover mode switch to connect the 10BASE-TModule directly to another
10BASE-T Module without the need for an external crossover adapter. One
port must be crossed over and the other port (port 8) must be uncrossed
when connecting a 10BASE-TModule to another 10BASE-TModule. If both
ports are crossed, you must use an external crossover adapter to provide a
proper connection.
The Off position disables crossover mode (uncrosses) and the On position
enables crossover mode (default), therefore, port eight is initially crossed
over.
Squelch Mode Sw itch
The Squelch mode switch allows you to set the Squelch level to high
(normal) or low (sensitive). The On position sets the Squelch level to high
(default). The High Squelch level conforms to the proposed 10BASE-T
standard. In general, 3Com recommends using High Squelch.
Introduction 1 - 7
The Off position sets the Squelch level to low. When the Squelch level is set
to low, the ports are able to receive weaker signals. Note that Low Squelch
mode does not conform to the 10BASE-T standard. If you change the
module's Squelch level to low, you must change the 10BASE-T Transceiver
Squelch level to low also. Refer to the ONline Ethernet 10BASE-T
Transceiver Installation Guide for information on setting the transceiver
Squelch level.
On unshielded twisted pair cable, setting the Squelch level to low increases
the achievable link distance by approximately 25% to 50% , but with the
added risk of losing packets to impulse noise. Do not use Low Squelch
mode if your network should experience too many illegally short packets
(runts). This problem will occur if there is significant external noise around
the link.
Setting the Squelch level to low in conjunction with shielded twisted pair
wiring increases the achievable link distance without sacrificing noise
immunity. Thus, there is no realdrawback in using Low Squelch on shielded
twisted pair.
To gain the extended link distance achieved by using Low Squelch mode,
you must use qualified data grade shielded twisted pair cable or qualified
high performance unshielded cable. IBM Type 1 shielded cable (with an
appropriate RJ45 to Type 1 connector), among others, meets this
requirement. If you are unsure of the grade of twisted pair cable to use, set
the Squelch level to high, or call 3Com for a list of qualified cables to use in
extended distance applications.
Channel Select Sw itch Settings
The ONline Ethernet 10BASE-T Module is equipped with the technology to
work with the ONline System Concentrator's unique TriChannel™
architecture. This feature allows you to assign the module to any of three
channels (or none) on the ONline System Concentrator backplane. Refer to
Chapter 1 in the ONline System Concentrator Installation and Operation
Guide for a complete discussion of ONline's TriChannel architecture.
The channel select switch settings (switches 2 and 3) on dip switch SW3 let
you select a channel. Switches 2 and 3 are factory set to On, therefore, the
1 - 8 ONline Ethernet 10BASE-T Module User’s Guide
10BASE-T Module is initially configured to channel 1. To reconfigure the
module to a different channel, refer to the information in Table 1-4.
Table 1-4. Dip Sw itch SW3 Settings and Interpretations for
Sw itches 2 and 3
Sw itch 2
Sw itch 3
Channel Selection
Switch Setting
On
On
Off
Off
On
Off
On
Off
1 (default)
2
3
Isolated (module
operates independent of
any channel)
If you have an ONline Ethernet Network Management Module installed in
your concentrator, you can remotely override these switch settings.
Dip Sw itch SW6 (Link Integrity)
The eight switches on dip switch SW6 allow you to enable or disable Link
Integrity for each port. The switches are labeled 1 through 8 and
correspond to the eight ports. The On position enables Link Integrity for
each port (default) and the Off position disables Link Integrity for each
port. The switch settings are initially configured in the On position,
therefore, all eight ports have Link Integrity enabled, as per the 10BASE-T
standard.
In general, you should enable Link Integrity. To conform to the 10BASE-T
standard, for example, a connection requires Link Integrity to be enabled.
You must disable Link Integrity to connect to older equipment which does
not conform to the 10BASE-T standard. Link Integrity must either be
enabled at both ends of the link or disabled at both ends or the module will
report a Link Integrity error.
Introduction 1 - 9
If you enable a port and disable Link Integrity, the Status LED is on for 10
seconds and blinks off for 400 msecs to indicate that Link Integrity is
disabled.
Table 1-5 lists the settings and functions for switches 1 through 8.
Table 1-5. Dip Sw itch SW6 Settings and Interpretations
Factory
Default
Sw itch Setting
Sw itch
Function
Off
On
1 - 8
Enable/disable link integrity enable
disable
enable
If you have an ONline Ethernet Network Management Module installed in
your Concentrator, you can remotely override these switch settings.
Related Features
The following sections describe functions which allow you to:
❑ check the module's channel assignment and LED functionality
❑ remotely manage the 10BASE-T Module
LED and Channel Verification
The ONline Controller Module is equipped with an LED/Channel Check
button on the front panel. The LED/Channel Check button has two
functions: it causes all LEDs in all modules in the concentrator to light and it
causes each module to identify the channel to which it is assigned. When
you activate this button, it causes all module LEDs to light for
approximately five seconds. Any LED that does not light is defective.
After the five seconds elapse, the diagnostic continues with a channel
check of all modules. This channel check causes each module's Status LEDs
to blink a number of times corresponding to the channel to which it is
1 - 10 ONline Ethernet 10BASE-T Module User’s Guide
assigned. The channelchecksequence repeatsfive times. Table 1-6 explains
the channel check codes.
Table 1-6. Channel Check Codes
LED State
1 Blink
Channel Configuration
Module is configured for channel 1
Module is configured for channel 2
Module is configured for channel 3
2 Blinks
3 Blinks
Off
Isolated (module operates independent of any
channel)
The LED/Channel Check button and the Controller Module are explained in
more detail in the ONline Controller Module Installation Guide.
The ONline Ethernet Netw ork Management Module
The ONline Network Management Module provides remote network
management capabilities for the ONline System Concentrator and its
modules. The Management Module can also remotely override the
following dip switch settings of the 10BASE-T Module:
❑ enable/disable each port
(SET PORT 6.5 MODE ENABLE)
❑ enable/disable Link Integrity for each port
(SET PORT 3.2 LINK_INTEGRITY ENABLE)
❑ set Squelch to high level or low level per port
(SET PORT 5.1 SQUELCH LOW)
❑ enable/disable crossover mode for port 8
(SET MODULE 5 CROSSOVER DISABLE)
Introduction 1 - 11
❑ change channel selection (per module)
(SET MODULE 4 CHANNEL 2)
The ONline Ethernet Management Module allows you to set redundancy
between the ports. Refer to Redundant Links in Chapter 2 for an example
of setting redundancy between concentrators using 10BASE-T Modules.
Refer to the ONline Ethernet Network Management Module Installation
and Operation Guide for additional information on the Network
Management features.
1 - 12 ONline Ethernet 10BASE-T Module User’s Guide
Designing and
Expanding the Netw ork
2
This appendix contains configuration information that will help you to
design your network. Install all equipment using only approved cables for
proper operation. Refer to Appendix A in the Twisted Pair Connectors and
Cables section for information on twisted pair connector and cable
requirements.
This appendix describes how to configure your network with the ONline
System Concentrator and the ONline Ethernet 10BASE-T Module. It also
provides examples of alternative network cabling structures and rules for
configuring Ethernet networks. There are five sections:
❑ Network Diameter Calculations: General Rules
❑ Fiber Backbone, Twisted Pair To-The-Desk
❑ Twisted Pair Backbone, Twisted Pair To-The-Desk
❑ Redundant Links
❑ Patch Panels
Designing and Expanding the Network 2 - 1
Understanding the General Rules
As part of your network design, it is important to consider your network
size. For instance, is the network (end-to-end) 100 meters, 1000 meters,
4000 meters, or more? What are your plans for expansion? Your answers
play a role in how you configure your network. For example, once the
network expands beyond a certain size, you need to add a bridge or other
internetworking device.
This section describes general rules for configuring an Ethernet network
using fiber as the backbone medium. It also provides rules to ensure that
your network configuration conforms to distance limitations imposed by
Ethernet and networking equipment.
This section includes:
❑ Basic Network Rules
❑ LAN Equivalence
Basic Netw ork Rules
This section outlines the basic network rules and 3Com recommendations
for these rules. For more hardware-specific information on the 10-Port
module, refer to Appendix A.
2 - 2 ONline Ethernet 10BASE-T Module User’s Guide
Table 2-1 outlinesthe seven basic rules to keep in mind when you construct
your network.
Table 2-1. Seven Basic Netw ork Rules
Rule
Definition
Recommendations/Notes
1
If possible, use
10BASE-FB as the
backbone medium.
Use 62.5 micron cable to conform
with the IEEE 10BASE-F and
upcoming ANSI FDDI standards.
Use ST-type connectors.
2
Wire the backbone in Make sure to lay extra fiber cables.
a star topology to
isolate faults.
The extra cost is small and you will
find you need them asyour network
grows.
The star topology conforms to FDDI
wiring as well -- just make sure to
run at least two fiber strands to
every backbone connection.
3
The maximum Fiber
Ethernet network
diameter is 4200
The 4200 meters is the maximum
distance between any two
transceivers on the network.
meters of fiber cable.
The 4200 meters does not include
the transceivercable (that is, drop or
patch cable) that connects a device
with an external transceiver.
Transceiver cables can extend up to
50 meters. Thus, total network
diameter can be as much as 4300
meters (4200 m + 2 * 50 m)
between any two nodes.
Designing and Expanding the Network 2 - 3
Table 2-1. Seven Basic Netw ork Rules (Continued)
Rule
Definition
Recommendations/Notes
4
Certain LAN devices
Many LAN products delay the signal
on the network shrink that goes through them. This is
the maximum Fiber
Ethernet network
diameter to less than
4200 meters.
known as equivalent distance. Every
microsecond delay reduces the
maximum link distance. In fact,
every microsecond delayshrinks the
network diameter by approximately
200 meters of fiber cable. Table 2-2
lists the Equivalent Distances for
other 3Com products.
5
Assume that one
meter of coaxial or
This is a conservative rule of thumb.
For example, the actual equivalence
twisted pair is equal to is about 1.1 meters of coaxial for
one meter of fiber
cable.
every meter of fiber. For simplicity,
assume one meter.
2 - 4 ONline Ethernet 10BASE-T Module User’s Guide
Table 2-1. Seven Basic Netw ork Rules (Continued)
Rule
Definition
Recommendations/Notes
6
The fiberlinkdistances In general, on 62.5 micron cable,
must not exceed the
limits imposed by the
you can go up to 4000 meters
point-to-point using the ONcore or
optical power budget. ONline Fiber Modules. If you have
poor quality cable or cross many
patch panels, you may have to
sacrifice some distance.
Some older Ethernet fiber optic
products are less powerful than
ONcore Fiber Module optics. So
when connecting to these products,
remember that the least powerful
device determines the maximum
point-to-point distance.
7
When in doubt, use a If you are not certain if you have
bridge.
exceeded allowable network
distances, use a bridge to extend
the network.
Designing and Expanding the Network 2 - 5
LAN Equivalence
LAN equivalence is the sum of both the incoming and outgoing module
port signals. Different modules, however, have different equivalent
distances. Table 2-2 lists the LAN product equivalent distances.
Table 2-2. LAN Product Equivalent Distances
Equivalent
LAN Product
Distance (meters)
ONcore Ethernet 10-Port 10BASE-FB Module
Incoming signal to fiber port
190
140
50
Outgoing signal from fiber port
ONcore Ethernet 10BASE-T Module
Incoming signal to TP port
585
420
165
585
420
165
190
140
50
Outgoing signal from TP port
ONline Ethernet 10BASE-T Modules
Incoming signal to TP port
Outgoing signal from TP port
ONline Ethernet Fiber or 10BASE-FB Modules
Incoming signal to fiber port
Outgoing signal from fiber port
ONline Ethernet FOIRL Module
Incoming signal to fiber port
560
330
230
0
Outgoing signal from fiber port
ONline Ethernet Transceiver Module
10BASE-FB Star Coupler (8 or 14 port) 26
180
2 - 6 ONline Ethernet 10BASE-T Module User’s Guide
Table 2-2. LAN Product Equivalent Distances (Continued)
Equivalent
Distance (meters)
LAN Product
ONline Ethernet BNC Module
Incoming signal to BNC port
Outgoing signal from BNC port
ONline Ethernet Repeater Module
Incoming signal to AUI port
Outgoing signal from AUI port
IEEE Repeater
900
450
450
800
600
200
800
Fiber Backbone, Tw isted Pair To-The-Desk
When you configure a network with unshielded or shielded twisted pair
cabling to-the-desk and fiber for the backbone, there are only three
additional rules you need to be aware of:
❑ There can be no more than eight 10BASE-T Modules (5108M-TP) in
the path between any two transceivers due to Ethernet's
four-repeater rule (each 10BASE-T Module counts as a 1/2 repeater).
You must add a bridge if you have more than eight 10BASE-T
Modules serially connected.
❑ There is an equivalent fiber distance for the ONline Fiber Modules
(see Rule 4). The equivalent is:
–
140 metersforsignalsthat externallyentera FiberModule
port
–
50 meters for signals that internally enter a Fiber Module
via the ONline Concentrator backplane
Designing and Expanding the Network 2 - 7
❑ There is an equivalent fiber distance for the 10BASE-T Modules (see
Rule 4). The equivalence is:
–
420 meters for signals that externally enter a 10BASE-T
Module port
–
165 meters for signals that internally enter a 10BASE-T
Module via the ONline Concentrator backplane
Thus, for every pair of 10BASE-T Modules that a signal goes through, there
is a fiber equivalent distance of 585 meters (420 m + 165 m = 585 m). This
is also true if a signal makes a roundtrip through a single 10BASE-TModule,
i.e., enters a 10BASE-T port externally and exits through another port on
the same 10BASE-T Module. This counts as 585 meters of fiber equivalent
distance, and as a full repeater.
Fiber Backbone, Tw isted Pair To-The-Desk Example
In the sample configuration shown in Figure 2-1, we determine if the
transceivers are within legal Ethernet limits. This example is applicable to
both unshielded and shielded twisted pair cables. Note that 22 gauge
unshielded twisted pair cable is used to connect 10BASE-T Transceivers to
the 10BASE-T Modules in the concentrators.
The first step is to identify the two transceivers that are likely to be the
greatest fiber equivalent distance apart. In this case, they are 10BASE-T
Transceivers A and B.
2 - 8 ONline Ethernet 10BASE-T Module User’s Guide
.
Figure 2-1. Sample Configuration Distance Calculation
Use the following steps to determine whether your network configuration
is legal:
1. Begin with 4.2 km (4200 m) since this is the maximum network
diameter for a pure fiber network (Rule 3).
2. Subtract 100 m for the signal exiting the Fiber Modules in
concentrators A and C (2 * 50) and 280 m for the signal entering the
Fiber Modules in concentrators C and B (2 * 140) as explained in Rule
4 and defined in Table 2-2.
3. Subtract 420 m of fiber equivalent distance for the signal entering the
10BASE-T Module in concentrator A and 165 m for the signal exiting
the 10BASE-T Module in concentrator B (Rule 4).
4. Subtract all cable lengths between the two transceivers and if the
result is greater than zero, the configuration is within legal Ethernet
limits (Rule 5).
Designing and Expanding the Network 2 - 9
For the configuration shown in Figure 2-1 to work, the fiber equivalent
distance between transceiver A and transceiver B must be less than 4200
meters. As you can see in the calculation, there are still 1510 meters left for
expansion in this configuration.
Be aware that the link from a 10BASE-T Module to a 10BASE-T Transceiver
should not exceed the distances as defined in Table 2-3. In this example,
the link cannot exceed 150 meters, using the 10BASE-T standard High
Squelch mode and 22 gauge wire.
Table 2-3. Maximum Link Distance on Tw isted Pair
Cable Gauge
Supports Link Distances Up To:
Unshielded Tw isted Pair: High Squelch
10BASE-T
Low Squelch
22 (.6mm)
24 (.5mm)
150m
125m
200m
150m
Shielded Tw isted Pair:
IBM Type 1
High Squelch
Low Squelch
22 (.6mm)
200m
300m
In areas of low noise, the Squelch level can be lowered to accept weaker
signals. (Low Squelch does not conform to the 10BASE-T standard.) This
allows the acceptable linkdistance to increase to 200 meters. The 10BASE-T
standard limits link distance to approximately 200 meters (equivalent to
1 µsec of delay) on unshielded twisted pair.
10BASE-T signaling can also be used on shielded twisted pair even though
the standard does not include shielded twisted pair in its specification.
Since external noise does not affect signals on shielded twisted pair, there is
no restriction in using the Low Squelch level. Using Low Squelch on
shielded twisted pair allows link distances of up to 300 meters.
Nevertheless, 3Com recommends that you always use the High Squelch
setting except in situations where the link distance exceeds 200 meters.
2 - 10 ONline Ethernet 10BASE-T Module User’s Guide
Tw isted Pair Backbone, Tw isted Pair To-The-Desk
In constructing a twisted pair backbone, one add itional configuration rule
must be considered:
❑ There can be no more than eight 10BASE-T Modules in the path
between any two transceivers due to the Ethernet four-repeater
rule (each 10BASE-T Module counts as a 1/2 repeater). You must
add a bridge if you have more than eight 10BASE-T Modules
serially connected.
The configuration in Figure 2-2 illustrates a possible unshielded twisted pair
network using 22 gauge cable.
Figure 2-2. Unshielded Tw isted Pair Netw ork
Note that when connecting two concentrators with twisted pair cable, use
port 8 on one of the 10BASE-T Modules and disable crossover mode for
that port. This allows a direct connection to another 10BASE-T Module
without the need for an intervening adapter. (Refer to Dip Switch SW3
(Crossover Mode, ChannelSelect, Squelch)in Chapter 1 for information on
crossover mode and the crossover mode switch setting.)
Designing and Expanding the Network 2 - 11
While there is no fiber in this configuration, the fiber equivalent distance
can be calculated as follows:
Total link distance: 150 m + 100 m + 100 m + 50 m + 20 m = 420 m
Total equivalent distance of 10BASE-T Modules:
4 * 420 m + 4 * 165 m = 2340 m
(signal externally enters four 10BASE-T Modules: 4 * 420 m)
(signal enters four 10BASE-T Modules from the backplane: 4 * 165 m)
Total equivalent distance: 420 m + 2340 m = 2760 m
Since the total equivalent distance (2760 m) is less than 4200 meters, this is
a legitimate configuration.
Note that if shielded twisted pair cabling is used, each link in the network
could run up to 300 meters using Low Squelch (refer to Dip Switch SW3
(Crossover Mode, ChannelSelect, Squelch)in Chapter 1 for information on
Squelch levels and the Squelch dip switch setting). Low Squelch is
acceptable for all shielded twisted pair applications since external noise is
not a problem.
Redundant Links
You can implement twisted pair link redundancy between ONline System
Concentrators using Network Management. Figure 2-3 below shows an
example of a redundant configuration between concentrators using
10BASE-T Modules.
Figure 2-3. Redundant Tw isted Pair Configuration
2 - 12 ONline Ethernet 10BASE-T Module User’s Guide
To set redundancy between two 10BASE-T Modules, connect two links
between the modules. The redundant link must be connected to a port on
the same 10BASE-T Module as the primary link. Use a crossover adapter
between each link unless you choose to uncross port 8 on one of the
modules to make the connection. Refer to Chapter 1 for information on
using crossover mode. Then use the SET PORT <slot.port> MODE
REDUNDANT <slot.port> command to specify which port is the primary link
and which is the backup link.
Note: If the 10BASE-T Modules are powered down, and then
brought back up without the Ethernet Management
Module present, a network loop could occur. To prevent a
potential failure, 3Com advises that you disable the Port
Enable dip switch setting for the backup port on one of the
10BASE-T Modules.
Once redundancy is configured, a switchover will occur under three
conditions: a link failure; port partition; or a jabber condition. The
switchover occurs when the primary link fails. (Note that in the unlikely
event of a partial break in the link, a switchover may not occur. In this
situation, use Network Management to manually switch over the ports.)
Once the switchover occurs, and the primary link becomes operational, a
switch-over back to the primary link happens automatically if the cause of
the original switchover was a link failure. If a jabber condition causes the
switchover, the link will not automatically switch back to the primary once
the problem is resolved. In this case, use Network Management to
manually switch back to the primary link.
Refer to the ONline Ethernet Network Management Module Installation
and Operation Guide for information on setting redundancy between
10BASE-T Module ports.
Designing and Expanding the Network 2 - 13
Patch Panels
Patch panels weaken signals, thereby reducing achievable link distances.
3Com includes the use of one patch panel in the 150 meter link distance
calculation. However, each additional patch panel in the link reduces the
150 meter link distance by approximately 10 meters.
In the example in Figure 2-2, if two patch panels were used between the
top right PC and the top right concentrator, the link distance of 150 meters
would have to be shortened to 140 meters. This is because the maximum
allowable linkdistance on 22 gauge wire using 10BASE-Tsignaling with two
intervening patch panels is 150 meters minus approximately 10 meters.
Note that a patch panel installed between the bottom right PC and the
bottom left concentrator would not affect the link since it is only 20 meters.
2 - 14 ONline Ethernet 10BASE-T Module User’s Guide
Installing and
Operating the Module
3
This chapter describes the precautionary, unpacking, and installation
procedures for the Ethernet 10BASE-T Module.
Precautionary Procedures
Electrostatic discharge (ESD) can damage static-sensitive devices on circuit
boards. Follow these precautions when you handle the 10BASE-T Module.
❑ Do not remove the board from its anti-static shielding bag until you
are ready to inspect it.
❑ Handle the board by the faceplate.
Use proper grounding techniques when you install the 10BASE-T Module.
These techniques include using a foot strap and grounded mat or wearing
a grounded static discharge wrist strap. An alternate method is to touch
the grounded rack or other source of ground just before you handle the
module.
Installing and Operating the Module 3 - 1
Unpacking Procedures
Use the following procedure when unpacking your 10BASE-T Module.
1. Verify that the 10BASE-T Module is the correct model by matching
the model number listed on the side of the shipping carton to the
model number you ordered (5108M-TP).
Note that the product model number printed on the shipping box
differs from the model number on the product. The model number
on the shipping box contains the prefix ’3C9’.
2. Remove the 10BASE-T Module from the shipping carton.
3. Remove the module from the anti-static shielding bag and inspect it
for damage. Always handle the 10BASE-T Module by the faceplate
being careful not to touch the components.
If the module appears to be damaged, replace it in the anti-static
shielding bag, return it to the shipping carton, and contact your local
supplier.
3Com suggests you keep the shipping carton and anti-static shielding bag
in which your module was shipped in case you later want to repackage the
module for storage or shipment.
We also suggest that you record the serial number of your 10BASE-T
Module. We have provided a log for this and other information specific to
your modules under the Slot Usage Chart in Appendix B of the ONline
System Concentrator Installation and Operation Guide.
Installation Procedures
You do not need to power down the ONline System Concentrator to install
the 10BASE-T Module. You can insert the module while the concentrator is
operating (called a hot insertion). Follow the steps below to install the
10BASE-T Module.
3 - 2 ONline Ethernet 10BASE-T Module User’s Guide
1. Set the dip switches on the board to the settings you want, if
different than the default values. (Refer to Table 1-2, Table 1-3,
Table 1-4, and Table 1-5 for an explanation of the dip switch settings.)
2. Locate a blank slot in the concentrator. If there is no blank slot, you
must remove a blank panel on the concentrator to expose a slot for
3. Insert the module into the board guides at the top and bottom of the
slot and slide it into the concentrator. Makesure the connector is well
seated into the backplane of the concentrator.
Figure 3-1 shows the installation of the 10BASE-T Module.
Figure 3-1. Installing a 10BASE-T Module
Installing and Operating the Module 3 - 3
4. Fasten the spring-loaded screws on the front of the 10BASE-TModule
face-plate to the concentrator with your fingers (do not overtighten).
5. Attach the twisted pair cable to the port on the front of the 10BASE-T
Module as shown in Figure 3-2. Then attach the other end of the
cable to another 10BASE-T Module, a 10BASE-T Transceiver, or a
10BASE-T Adapter Card.
Figure 3-2 shows a cable attached to the 10BASE-T Module.
Figure 3-2. 10BASE-T Module Cable Connection
3 - 4 ONline Ethernet 10BASE-T Module User’s Guide
Troubleshooting
4
This chapter describes troubleshooting procedures for the ONline Ethernet
10BASE-T Module. Information on troubleshooting will assist you in
verifying operation. Typical fault conditions are addressed in this chapter.
Troubleshooting
Diagnostic features are covered in Table 1-1 on page 1-4. Table 4-1 and
Table 4-2 in this chapter cover fault conditions and troubleshooting
suggestions for the 10BASE-T Module. This chapter is divided into the
following parts:
❑ Troubleshooting With the Port Status LEDs
❑ Troubleshooting With the Activity LEDs
❑ Technical Assistance
Troubleshooting 4 - 1
Troubleshooting With the Status LEDs
A blinking Port Status indicator may be a sign that the port detects a
potential problem. Once a port detects a problem, you can further analyze
the problem by counting the number of blinks. Table 4-1 provides
troubleshooting suggestions for each of the blinking sequences.
Table 4-1. Troubleshooting With the Port Status LEDs
Possible
Problem
Troubleshooting
Suggestions
LED State
Indication
Off
Port
Port disabled
Enable port.
Disabled
10BASE-T
Module not
powered
Check the Controller
Module Power LEDs.
Broken LED
Press the LED/Channel
Check button on the
Controller Module.
Bad 10BASE-T
Module
Replace module.
4 - 2 ONline Ethernet 10BASE-T Module User’s Guide
Table 4-1. Troubleshooting With the Port Status LEDs (Continued)
Possible
Problem
Troubleshooting
Suggestions
LED State
Indication
1 Blink
Link
Cable not
Connect cable.
Integrity
Error
connected
Cable broken
Check cable with cable
tester. Repair or replace
cable.
Cable too long
Try a shorter cable.
Remote
Enable Link Integrity at
remote connection or if
the remote linkdoesnot
have Link Integrity,
connection has
Link Integrity
disabled
disable Link Integrity at
local connection.
Weak or no
signal - link
distance too
long
Change Squelch level
from high to low (low
setting does not
conform to the
10BASE-T standard).
Bad port
Try another port.
Device attached This is not a problem.
to transceiver at
other end is not
powered on
Troubleshooting 4 - 3
Table 4-1. Troubleshooting With the Port Status LEDs (Continued)
Possible
Problem
Troubleshooting
Suggestions
LED State
Indication
2 Blinks
Port
Partitioning
Faulty cable
Check cable with cable
tester. Repair or replace
cable.
Network
overloaded
Reassign users to
another channel to
balance the load.
Jabber
condition
Transceiver
attached to the
port is jabbering
or has DTE
jabber
Try another port or
replace module.
Timed
Link
None
This is not a problem.
You may want Link
Integrity disabled.
Blinks (LED Integrity
is on for 10 Disabled
seconds,
blinks off
for 400
msecs)
4 - 4 ONline Ethernet 10BASE-T Module User’s Guide
Troubleshooting With the Activity LEDs
There may be situations where a port's Activity LED maynot light. Use the
troubleshooting suggestions in Table 4-2 to help isolate why this has
occurred.
Table 4-2. Troubleshooting With the Port Activity LEDs
LED
State
Troubleshooting
Solutions
LED Name
Possible Problem
Activity
(Ports 1 - 8)
Off
There is no traffic
received from the
segment (normal)
None.
The port is disabled Check the port enable dip
switch setting.
The power is off
Check the Controller
Module Power LEDs.
The Activity LEDhas Press the LED/Channel
burnt out
Check button on the
Controller Module.
The 10BASE-T
Module port is
faulty
Connect the cable to a
different port.
The module
connection to the
backplane is bad
Reinsert the 10BASE-T
Module. If this fails, try
anotherconcentratorslot.
The 10BASE-T
Module is faulty
Try a different 10BASE-T
Module.
Troubleshooting 4 - 5
Technical Assistance
You can receive assistance for installing and troubleshooting the 10BASE-T
Module by calling either your 3Com reseller or 3Com Technical Support. Be
prepared to supply a representative with the following information:
❑ Description of the problem
❑ Steps you have taken to try and correct the problem
❑ Type and software version of the ONline network management
module being used
❑ Version of software installed on your 10BASE-T Module
❑ Status of the front panel LEDs
❑ Configuration of your concentrator
(you may find it helpful to refer to the Slot Usage Chart in Appendix B
of the ONline System Concentrator Installation and Operation Guide
for a record of this information)
Reber to Appendix B for instructions on contacting Technical Support for
your product.
4 - 6 ONline Ethernet 10BASE-T Module User’s Guide
Specifications
A
ONline Ethernet 10BASE-T Module Specifications
This appendix lists specifications for the 10BASE-T Module. There are five
subsections:
❑ Electrical Specifications
❑ Environmental Specifications
❑ Mechanical Specifications
❑ General Specifications
❑ Twisted Pair Connectors and Cables
Electrical Specifications
Backplane Interface: 96-pin edge connector, compatible with the 3Com
ONline System Concentrators.
Power Requirements: 1.75 A for 5V
Fuse: 4.0 Amps Fast blow
Watts: 8.75
Specifications A - 1
Environmental Specifications
Operating Temperature: 0° to 50° C (32° to 122° F)
Storage Temperature: -30° to 65° C (-22° to 149° F)
Humidity: less than 95% , non-condensing
BTU/hr: 30
Mechanical Specifications
Dimensions: 1.0" W x 10.25" L x 8.5" H
(2.54 cm x 26.04 cm x 21.6 cm)
Weight: 1.25 lb. (0.57 kg.)
General Specifications
Data Rate: 10 Mbps (million bits per second)
Data modulation: Manchester
Diagnostic modulation: Link Integrity pulse
Collision detection: 100% deterministic
Maximum number of nodes: 1024
Configuration rules: supports IEEE 802.3 controllers and IEEE 802.3
repeaters
Jabber Protection: 6.5 milliseconds
Port Connectors: Shielded 8-pin modular telephone jack, compatible with
an unshielded connector
Cabling: 22, 24, or 26 AWG unshielded or shielded twisted pair cable
Cable differential impedance: 85 ohms to 150 ohms over 1 to 16 MHz band
A - 2 ONline Ethernet 10BASE-T Module User’s Guide
Cable propagation velocity: >.585c
Host Interface: 3Com ONline System Concentrator bus interface standard
Installation Attachment: Two thumbscrews on the mounting bracket
Tw isted Pair Connectors and Cables
There are many types of cables and connectors that you can use to link
your 10BASE-T Module to your network. These cables and connectors are
explained in the following sections. Use this information to ensure that the
cables and connecting hardware meet requirements. For proper operation,
use only approved cables when you install all equipment. This section is
divided into the following parts:
❑ Twisted Pair Connectors
❑ Twisted Pair Cables
Tw isted Pair Connectors
The IEEE802.3 10BASE-Tstandard for pin-outs must be used. The following
cable standard must be used. 10BASE-T uses 2 pairs of wire: pins 1 & 2 and
pins 3 & 6. If the pairs are not configured this way, the connection will not
work properly. Datagrade cable should have the following pin pairings:
❑ pins 4 and 5 are pair 1
❑ pins 3 and 6 are pair 2
❑ pins 1 and 2 are pair 3
❑ pins 7 and 8 are pair 4
Specifications A - 3
Refer to Figure A-1 for an example of this connector and the cable pin-outs.
Pair 2
Pair 3
Pair 1
Pair4
1
2
3
4
5
6
7
8
W-G
G
W-O BL W-BL O W-BR BR
Jack Positions
Figure A-1. RJ45 Connector Pin-outs
Some installations may have 50-pin Telco connectors at the wiring closet.
We recommend using a patch panel that converts from 50-pin to RJ45-type
connectors. This allows direct connection to the ONline Ethernet 10BASE-T
Module in your ONline System Concentrator.
Tw isted Pair Cables
The cables that are supported must meet the following qualifications:
❑ 22, 24, or 26 gauge twisted pair cable
❑ 80 to 150 ohm impedance
❑ minimum of 2 pairs
Usually, a pair on a twisted pair cable is designated by a solid color wire
twisted with a striped wire with the same color.
A - 4 ONline Ethernet 10BASE-T Module User’s Guide
Connecting Tw isted Pair Cables
We recommend that you connect cables first at the active concentrator
location, and connect transceivers second. Refer to the ONline System
Concentrator Installation and Operation Guide for more information about
the ONline System Concentrator connections.
Specifications A - 5
Technical Support
B
3Com provides easy access to technical support information through a
variety of services. This appendix describes the following services:
❑ On-line Technical Support
❑ Support from Your Network Supplier
❑ Support from 3Com
❑ Returning Products for Repair
❑ Accessing the 3Com MIB
❑ 3Com Technical Publications
On-line Technical Support
3Com offers worldwide product support through the following on-line
systems:
❑ Email Technical Service
❑ World Wide Web Site
Technical Support B - 1
Email Technical Support
You can contact the Integrated Systems Division (formerly Chipcom) on the
Internet for technical support using the e-mail address
techsupp@chipcom.com.
World Wide Web Site
You can access the latest networking information on the 3Com World
Wide Web site by entering our URL into your Internet browser:
This service features news and information about 3Com products,
customer service and support, the 3Com latest news releases, selected
™
articles from 3TECH , the 3Com award-winning technical journal, and
more.
You can contact the Integrated Systems Division on the World Wide Web
by entering our URL into your Internet browser:
There are links between both WWW pages to view information from all
3Com divisions.
Support from Your Netw ork Supplier
If additional assistance is required, contact your network supplier. Many
suppliersare authorized 3Com service partnerswho are qualified to provide
a variety of services, including network planning, installation, hardware
maintenance, application training, and support services.
B - 2 ONline Ethernet 10BASE-T Module User’s Guide
When you contact your network supplier for assistance, have the following
information ready:
❑ Diagnostic error messages
❑ A list of system hardware and software, including revision levels
❑ Details about recent configuration changes, if applicable
If you are unable to contact your network supplier, see the following
section on how to contact 3Com.
Support from 3Com
If you are unable to receive support from your network supplier, technical
support contracts are available from 3Com.
For direct access to customer service for Integrated Systems Division
products in:
❑ U.S.A. and Canada - call (800) 724-2447
❑ Asia Pacific - call (508) 787-5151
❑ Europe - Refer to the table below. For European countries not listed,
call 31 30 60 299 00.
Country
Belgium
Denmark
Finland
France
Telephone Number
0800 71429
800 17309
Country
Netherlands
Norway
Spain
Telephone Number
06 0227788
800 11376
0800 113153
05 917959
900 983125
Sweden
U.K.
020 795482
Germany
Ireland
0130 821502
1 800 553117
1678 79489
0800 966197
800 876-3266
U.S.
Italy
Technical Support B - 3
For access to customer service for all 3Com products, call (800) 876-3266.
You can also contact the Integrated Systems Division (ISD) on the Internet
by using the e-mail address techsupp@chipcom.com.
Returning Products for Repair
A product sent directly to 3Com for repair must first be assigned a Return
Materials Authorization (RMA) number. A product sent to 3Com without
an RMA number will be returned to the sender unopened, at the sender’s
expense.
To obtain an RMA number for Integrated Systems Division products
(formerly Chipcom), use the following numbers.
Country
Telephone Number
Fax Number
(508) 787-3400
No Fax
U.S. and Canada (800) 724-2447
Europe
(44) (1442) 275860
(508) 787-5296
Asia Pacific
(508) 787-3400
Accessing the 3Com MIB
The 3Com Management Information Base (MIB) for the Integrated Systems
Division describes commands that enable you to manage 3Com
SNMP-based products. The MIB is available over the Internet on an
anonymous FTP server. Updates to these MIBs are released as new 3Com
products are introduced.
To access Internet versions:
1. FTP to ftp.chipcom.com(151.104.9.65).
2. Enter the login name anonymous.
B - 4 ONline Ethernet 10BASE-T Module User’s Guide
3. Enter your full Internet e-mail address as the password
4. Change to the mib or schema directory using the cd /pub/mibsor
cd /pub/mibs/schemascommand.
5. To view the 3Com MIB, OID, or schema entries, enter the dir
command.
❑ To pause the display, press [CTRL-S].
❑ To continue the display, press [CTRL-Q].
6. Copy the MIB, OID, or schema files to your current directory using the
appropriate command (for example, get chipcom.mib).
7. To exit the FTP session, invoke the quitcommand.
3Com Technical Publications
If you have comments or questions on 3Com Integrated Systems Division
Technical Publicationsdocuments, please contact the TechnicalPublications
group by FAX (508) 229-1551.
Technical Support B - 5
Index
Numerics
D
3Com Bulletin Board Service (3ComBBS), B-3 Dip Switch Settings
Channel Select, 1-8, 1-9
Crossover Mode, 1-6, 1-7
Link Integrity, 1-9, 1-10
Port Status, 1-5
A
Audience of Manual, xi
Squelch Mode, 1-7, 1-8
Dip Switches, 1-4
B
Backbone
Fiber Medium, 2-2
bulletin board service, B-3
F
FCC notice, ii
Features, 1-1, 1-2
Fiber Link Distances, 2-5
Front Panel Indicators
Activity LEDs, 1-2, 1-4
Status Indicators, 1-2
Status LEDs, 1-4
C
Cable Types
Shielded Twisted Pair, 1-1
Unshielded Twisted Pair, 1-1
Cabling
Connectors, A-3, A-4
Fiber Backbone, 2-7, 2-8, 2-10
Redundant Links, 2-13
Twisted Pair Backbone, 2-11
Twisted Pair Connections, 2-10
Wire Types, A-4
I
Installation
Cabling, 3-4
Installing The Module, 3-3, 3-4
Configuration Rules
L
Fiber Backbone, 2-9
Configuration Rules
LAN Product Equivalent Distances, 2-6
Fiber Backbone, 2-7, 2-8
General, 2-2, 2-3, 2-5
Twisted Pair Backbone, 2-11, 2-12
Link Distances
Configuration Rules, 1-1
Index 1
U
M
Unshielded Twisted Pair, 2-8, 2-10, 2-11
MIB, B-4
V
N
VDE compliance, ii
network supplier support, B-2
W
O
Wire Types, 1-1
ONline Controller Module, 1-10
ONline Ethernet Management Module, 1-11,
1-12
on-line technical services, B-1
P
Patch Panels, 2-14
R
Redundancy, 2-13
returning products for repair, B-4
S
Shielded Twisted Pair, 2-10, 2-12
SNMP Commands, B-4
Star Topology, 2-3
T
Technical Assistance, 4-6
Technical Support, 4-6, B-1
Troubleshooting
Port Activity LEDs, 4-5
Port Status LEDs, 4-1, 4-3, 4-4
Technical Assistance, 4-6
Twisted Pair
Cables, A-4, A-5
Connections, A-5
Connectors, A-3, A-4
2 Index
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