DEC DECrepeater 90T User manual

DECrepeater90TOwner’sManual
Order Number EK–DETMR–OM.001
Digital Equipment Corporation

August 1991
The information in this document is subject to change without notice and should not
be construed as a commitment by Digital Equipment Corporation. Digital Equipment
Corporation assumes no responsibility for any errors that may appear in this document.
The software described in this document is furnished under a license and may be used or
copied only in accordance with the terms of such license.
No responsibility is assumed for the use or reliability of software on equipment that is not
supplied by Digital Equipment Corporation or its affiliated companies.
Restricted Rights: Use, duplication, or disclosure by the U. S. Government is subject to
restrictions as set forth in subparagraph (c) (1) (ii) of the Rights in Technical Data and
Computer Software clause at DFARS 252.227–7013.
Copyright © Digital Equipment Corporation 1991
All Rights Reserved.
Printed in U.S.A.
FCC NOTICE: The equipment described in this manual generates, uses, and may emit
radio frequency energy. The equipment has been type tested and found to comply with
the limits for a Class A computing device pursuant to Subpart J of Part 15 of FCC
Rules, which are designed to provide reasonable protection against such radio frequency
interference when operated in a commercial environment. Operation of this equipment in
a residential area may cause interference, in which case the user at his own expense may
be required to take measures to correct the interference.
The following are trademarks of Digital Equipment Corporation: DEC, DECbridge,
DECconnect, DEChub, DECnet, DECserver, Digital, LAT, ThinWire, VMS, VAX, and the
Digital logo.
This document was prepared and published by Educational Services Development and
Publishing, Digital Equipment Corporation.

Contents
About This Manual vii
1 INTRODUCTION
Features .............................................. 1
Quick Start ........................................... 3
LEDs and Connectors ................................... 4
2 Configuration
Configuration Rules ..................................... 6
Port Partitioning ....................................... 7
3 INSTALLATION
Standalone Installation . . . ............................... 8
Table Mounting ...................................... 8
Wall Mounting ....................................... 8
Connect the cables. ................................... 11
Install and Verify Devices. .............................. 13
Backplane Installation ................................... 13
Install and verify devices. .............................. 16
4 Management
Managing the DECrepeater 90T ........................... 17
Functions ........................................... 17
Components Needed................................... 18
Accessing the Maintenance Operations Protocol from VMS ..... 18
Accessing the Maintenance Operations Protocol from ULTRIX . . 19
iii

iv Contents
Console Carrier User Interface . . . ....................... 20
Console Carrier Command Language. ....................... 21
Command Parameters Description . ....................... 21
Command Descriptions . ............................... 22
Typical Management Techniques ........................... 27
Remote Network Management Using the DECbridge 90 . ...... 27
Management Disconnect ............................... 27
Messages ............................................. 31
Stand-alone Configuration Management ................... 33
5 Troubleshooting
DECrepeater 90T Standalone Troubleshooting . ............... 35
DECrepeater 90T Backplane Configuration Troubleshooting ...... 39
A DECrepeater 90T Specifications
Physical Dimensions .................................... 42
Environmental Specifications .............................. 43
Operating Environment . ............................... 43
Shipping Environment Specifications ...................... 43
Electrical Specifications . . . ............................... 44
Power Supply . ....................................... 44
DECrepeater 90T ..................................... 44
MJPinOut ........................................... 45
Parts List ........................................... 45
B Related Documentation
C Management Details
Designating a Hub Manager .............................. 48
Annotating the Bridge Address Table ....................... 49
Using the WGB Address Table for Work Group Management
Documentation ....................................... 50
Index

Contents v
Tables
1–1 Status LEDs ..................................... 4
2–1 Basic Configuration Rules ........................... 6
2–2 DECrepeater 90T Fault and Non-fault conditions . . . ...... 7
4–1 Summary of DECrepeater 90 Commands. ............... 21
4–2 DECbridge 90 Messages............................. 31
4–3 DECrepeater Status LEDs ........................... 34
5–1 Troubleshooting a DECrepeater 90T Standalone Unit ...... 35
5–2 Troubleshooting a DECrepeater 90T in a DEChub 90
Backplane ....................................... 39
A–1 MJPinOut ...................................... 45
A–2 Parts List . ....................................... 45

AboutThisManual
This guide describes how to install, operate, and maintain the Digital
Ethernet Twisted Pair Multiport Repeater - the DECrepeater 90T. The
DECrepeater 90T is a 9-port repeater designed for standalone operation
or as a managed repeater in the DEChub 90 Ethernet backplane.
Organization
This manual contains five chapters and three appendices.
• Chapter 1 provides an overview of the Ethernet Twisted Pair
Multiport Repeater and briefly describes the product’s features.
• Chapter 2 describes the configuration rules and conditions of operation
for the Ethernet Twisted Pair Multiport Repeater in a ThinWire
Ethernet system or standard Ethernet network.
• Chapter 3 provides instructions for installing the Ethernet Twisted
Pair Multiport Repeater.
• Chapter 4 provides information on managing the Ethernet Twisted
Pair Multiport Repeater on a network.
• Chapter 5 provides basic troubleshooting information.
• Appendix A details the system specifications and the parts list.
• Appendix B provides a list of related documents to help you become
more familiar with your new system.
• Appendix C provides more detailed information on management
issues.
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viii About This Manual
Conventions
Convention Meaning
NOTE Provides general information.
! A number in a black circle in text refers to
the corresponding number in an accompanying
illustration.
SHOW ADDRESS In text, commands are shown in all upper case
letters to differentiate them from regular text.
For the VMS operating system, you can enter
commands in either upper case or lower case
letters. For the ULTRIX operating system,
commands must be entered as indicated in the
examples.
DECbridge> Text that the system displays on the screen is
shown in monospaced type.
SHOW REPEATER 1 Text that you enter is shown in bold
monospaced type.
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1
INTRODUCTION
This chapter describes the DECrepeater 90T features and summarizes the
installation procedures.
Features
The DECrepeater 90T has the following features:
• Eight twisted pair ports
• One ThinWire port
• Operates as a standalone unit or as a managed repeater in a DEChub
90 with a DECbridge 90
• Backplane installable
The DECrepeater 90T is a 9-port repeater designed for the IEEE 802.3
CSMA/CD networks. The DECrepeater 90T has one ThinWire port and
eight twisted pair ports. The ThinWire port complies with the IEEE 802.3
standard for 10Base2 networks. The twisted pair ports comply with the
same standard for 10BaseT.
The repeater can be used in a standalone configuration or as a managed
repeater when it is installed in a Digital DEChub 90 Ethernet backplane
with a DECbridge 90. When operating as a standalone repeater, it is a
9-port unmanaged repeater with a separate power supply connected to
the unit by a cable with a 7-pin connector. The power supply is modular
and accommodates either a North American 120 Volt or an international
auto-ranging 240 Volt wall outlet. The following figure shows a typical
configuration of the DECrepeater 90T in an Ethernet Local Area Network
(LAN).
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2 INTRODUCTION
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WORKSTATION WORKSTATION DECSERVER |
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DECrepeater 90T DECrepeater 90C DECserver 90L
Segment
Work Group Bridge
Work Group −−− −−
COMPUTER 2
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Work Group
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PC
DECbridge 90
Backbone
SERVER
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COMPUTER 1
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Ethernet
ThinWire
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INTRODUCTION 3
Quick Start
The DECrepeater 90T is easy to install and use. It does not require
any programming or other assistance from system management. After
unpacking the unit:
1. Plug the connector from the power supply into the DECrepeater 90T,
then plug the power supply into a working ac wall outlet.
All LED indicators should be on. Only the Network Activity LED
turns on and then off.
2. Connect the unit to a properly terminated ThinWire Ethernet
segment.
3. Connect any personal computers, workstations, or other 10BaseT
devices using a straight-through pin-to-pin cable to each of the ports
you plan to use.
The Port Status Activity LEDs for unconnected ports should be off
when network traffic is established.
For more detailed information on configuring the DECrepeater 90T refer
to Chapter 2. For more detailed information on installing and using the
DECrepeater 90T refer to Chapter 3.
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4 INTRODUCTION
LEDs and Connectors
The next table describes the DECrepeater 90T LEDs and connectors,
shown in the illustration following the table.
Table 1–1 Status LEDs
! DC OK - When on, this LED indicates that the +5.0 VDC voltage
is normal. When off, the LED indicates that the voltage is
abnormal (for example, in a power failure.)
"
NETWORK ACTIVITY - This LED is on when network traffic is
being repeated. The LED is off when there is no network activity.
#
PORT 0 STATUS - When on, this LED indicates that the
functional status of PORT 0 is operational. When off, it indicates
that Port 0 has failed or a partitioned port condition exists. If the
LED is blinking the port has been partitioned by management.
$ Port Status Activity Indicator - There are eight green Port
Status Activity LEDs that are used to monitor the port activity.
The top Port Status Activity LED represents Port 1 and the
bottom LED represents Port 8. When on, the LEDs indicate that
the functional status of the represented port is operational. If the
LED is blinking the port has been partitioned by management.
% Port 0 Network Connector (BNC) - This connects the
DECrepeater 90T to the work group ThinWire segment. It is
not used when the unit is installed in the DEChub 90 backplane.
&
Port Connector (MJ) - These eight connectors are used to
connect workstations and PCs to the DECrepeater 90T. These
connectors have internal crossovers (indicated by the X.)
' Power Connector - Receives +5 volts from the DECrepeater
90T power supply. It is not used when the unit is installed in the
DEChub 90 backplane.
( Backplane Connector - This provides network and power
connections to the DECrepeater 90T when it is installed in the
DEChub 90 backplane.
) Back Cover - This is used with standalone units only. It covers
the backplane connector and mounting assembly.
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INTRODUCTION 5
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2
Configuration
This chapter contains the configuration rules you must follow for correct
installation of the DECrepeater 90T.
This chapter also contains information on port partitioning and the
different operations that cause the ports to partition. The DECrepeater
90T does not require any special instructions for it to operate correctly.
Configuration Rules
The following table contains the basic rules for ThinWire and Twisted
Pair segments.
Table 2–1 Basic Configuration Rules
Segment Rule
ThinWire Maximum length: 185 Meters.
Each ThinWire segment must always be terminated
with a 50 ohm terminator at each end.
Twisted Pair Maximum length: 100 Meters.
Twisted pair segments do not require termination.
The 10BaseT standard specifies the Twisted Pair cabling
performance requirements for applications of single and
multiple 10BaseT services in a single cable, and specifies
the allowable attenuation (loss) between the 10BaseT
transmitter and receiver.
Digital supports multiple 10BaseT services in a single
cable that meet the 10BaseT requirements for cable
performance and end-to-end loss. Contact your local
Digital Authorized Sales Representative for information
about support for other shared services.
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Configuration 7
Port Partitioning
Any messages or data packets received from any port by the repeater
are transmitted to all ports. The corresponding LED displays the port
status and the port partition activity. The LED is on when the port is
either active or not partitioned, and it is off when nothing is connected to
the port or the port is autopartitioned. When the port is partitioned by
management, the LED flashes approximately twice a second, independent
of any other partitioning.
The DECrepeater 90T status LEDs show the status of the repeater. The
status may or may not be a fault of the repeater. Table 2–2 contains
both repeater fault and non-repeater fault conditions. Each port is
automatically controlled and can be partitioned for any of the reasons
in the following table:
Table 2–2 DECrepeater 90T Fault and Non-fault conditions
LED Fault Non-fault
Port 0
Off Open or shorted cables, or cables incorrectly terminated or connected
without a T-connector
Nothing connected to the
port
Port 0-8
Flashing — Partitioned by management
Port 1-8
Off Open or shorted cables, or cables improperly terminated Nothing connected to the port
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3
INSTALLATION
The DECrepeater 90T can be placed on a table, mounted to a wall, or
installed in a DEChub 90 Ethernet backplane. Refer to the standalone
installation procedure to mount the unit to a wall. Refer to the backplane
installation procedure to install the unit in a DEChub 90 Ethernet
backplane.
Standalone Installation
Table Mounting
When you place the DECrepeater 90T on a table top, your only
requirement to follow the envirionmental specifications found in Appendix
A.
Wall Mounting
Select a location for the unit. The location should have access to a wall
outlet to supply the required voltage.
To wall-mount the unit, perform the following procedure:
1. Remove the back cover of the unit.
a. Insert a small screwdriver into the top mounting hole located on
the cover.
b. Lift the internal latch with the screwdriver and pull the cover
away and down from the top of the unit.
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INSTALLATION 9
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2. Locate the placement for the mounting screws.
3. Secure the cover to the wall using the mounting screws.
The screws should be tight enough to provide resistance if you try to
remove the back cover from the wall. Do not make them so tight that
the cover is distorted or cannot be removed from the wall.
4. Remove the back cover from the wall.
5. Attach the back cover to the repeater.
6. Mount the repeater onto the mounting screws.
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10 INSTALLATION
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INSTALLATION 11
Connect the cables.
1. Connect the cable from the power supply to the 7-pin power connector
on the DECrepeater 90T. Align the power symbol on the dc power
connector with the power symbol on the DECrepeater 90T and push
straight in.
2. Connect the DECrepeater 90T to the power supply.
• For a 240-volt wall outlet, connect the power supply cord to the
modular power supply, then to the wall outlet.
• For a 120-volt wall outlet, connect the power supply directly to the
wall outlet.
3. All the LED indicators turn on for approximately one-half second of
initial power up, then only the Network Activity LED turns off.
4. Connect the Ethernet ThinWire T-connector to the Port 0 BNC
Network connector. Terminate the T-connector with a 50 ohm
terminator or extend the Ethernet segment to the next device.
5. The Port 0 Status Activity LED should be on at varying intensities or
blinking to indicate the amount of traffic on the network.
6. Connect the Twisted Pair cables to ports 1-8.
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12 INSTALLATION
PC
or
Workstation
50 Ohm
Terminator
T-Connector
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