Digital Equipment VAXstation 2000 Installation and maintenance instructions

Workstations
and Micro VAX 2000
Network Guide
Order Number EK-NETAB-UG-002
digital equipment corporation
maynard, massachusetts

December 1986
October 1987
The information in this document is subject to change without notice and should not be construed as a
commitment by Digital Equipment Corporation.
Digital EquipmentCorporationassumesno responsibility for any errors that may appear in this document.
The software, ifany, described in this document is furnished undera license and maybe usedor copied only
in accordance with the terms of such license. No responsibility is assumedforthe use or reliabUity ofsoftware
or equipment that is not supplied by Digital Equipment Corporation or its affiliatedcompanies.
Copyright ©1986, 1987 by Digital Equipment Corporation.
All Rights Reserved.
The READER'S COMMENTS form on th^ last page of this document requests the user's critital evaluation to
assist in preparing future documentation.
The following are trademarks of Digital Equipment Corporation:
DEBET
MicroVAX UNIBUS
DEC
Microns
ULTRIX-32
DECconnect
PDP ULTRIX-32m
DECmate
P/OS
VAX
DECUS
Professional
VAXcluster
DECwriter Rainbow VAXstation
DEQNA
RSTS
VMS
DEUNA RSX VT
DIBOL
RT
Work Processor
MASSBUS
ThinWire
SDSBDSD
TM
ML-S754

^ Contents
Preface vu
Chapter 1 Overview
What Makes a Network? 1-1
Standard Ethernet 1-1
ThinWire Ethernet 1-1
Unshielded Twisted-Pair Ethernet 1-2
DECnet 1-3
Networking Capabilities of ULTRIX 1-3
Local Area VAXclusters 1-4
Chapter 2 Setting Up the Network
Standard Ethernet 2-1
Basic ThinWire Components 2-2
ThinWire Ethernet Cable 2-3
Connectors and Terminators 2-5
Additional Equipment 2-6
DIGITAL ThinWire Ethernet Multiport Repeater (DEMPR) . . . 2-6
DIGITAL ThinWire Ethernet Station Adapter (DESTA) 2-7
DEBETs — The Ethernet Bridge 2-8
ThinWire Configurations 2-8
DECconnect Approach 2-9
Daisy-chain Approach 2-10
Combined Daisy-chain and DECconnect Approach 2-10
Single Segment Configuration 2-11
Multisegment ThinWire Configuration 2-13
ThinWire Ethernet Rules 2-14
Configurations Symbols 2-14
III

Single Segment ThinWire Ethernet 2-15
Stand-alone DEMPR
2-17 ^
Combined Standard/ThinWire Ethernet LAN 2-18
Stand-alone Cascading DEMPRs
2-19
Stand-alone DELNI with DEMPRs 2-20
Local Bridge 2-21
Disconnecting Stations from ThinWire Ethernet 2-22
Local Area VAXcluster Configuration 2-23
Chapter 3 Installing ThinWire Hardware
Before You Start 3-1
Determining Your Needs 3-1
ThinWire Ethernet Cable 3-1
Connectors 3-1
Barrel Connectors and T-Connectors 3-2
DESTA and Transceiver Cable 3-2
Terminators 3-2
DEMPR 3-2
Estimating Your Needs 3-2
Planning the ThinWire Segment 3-3
Setting the Switch for ThinWire Ethernet 3-4
Connecting to a ThinWire Ethernet Segment 3-4
Connecting VAXstation 2000, Micro VAX 2000, or VAXmate .... 3-5
Connecting a Station with a Transceiver Cable 3-8
Connecting to an Existing ThinWire Network 3-12
How to Install a DEMPR 3-12
Stand-alone DEMPR 3-13
Connecting the DEMPR to Standard Ethernet 3-16
How to Lengthen a ThinWire Segment 3-16
How to Verify Network Installation for a VAXstation 2000 or
MicroVAX 2000 3-17
How to Verify Installation for a VAXmate 3-18
Troubleshooting the ThinWire Segment 3-18
Troubleshooting the DEMPR 3-19
Troubleshooting the DESTA 3-19
IV

Troubleshooting Network Software 3-19
Appendix A Associated Documents
Glossary
Index
Figures
2-1 Settingthe Switch for StandardEthernet 2-1
2-2 Connecting the Intermediary Cable 2-2
2-3 ThinWire Ethernet Cable 2-4
2-4 Connectors 2-5
2-5 DIGITAL ThinWire Ethernet Multiport Repeater (DEMPR). . . 2-6
2-6 DIGITAL ThinWire Ethernet Station Adapter (DESTA) 2-7
2-7 Symbols for Cables 2-8
2-8 DECconnect Method of Wiring 2-9
2-9 Single SegmentConfiguration 2-11
2-10 Connecting
ThinWire Ethernet to Standard Ethernet 2-12
2-11 Multisegment
ThinWire Configuration 2-13
2-12 Symbols for Configurations 2-14
2-13 Single Segment ThinWire Configuration 2-16
2-14 Stand-alone DEMPR with ThinWire Cables 2-17
2-15 DEMPR on Standard Ethernet 2-18
2-16 Stand-alone Cascading DEMPRs 2-19
2-17 Stand-alone DELNI with DEMPRs 2-20
2-18 Local Bridge 2-21
2-19 Disconnecting a Station from
ThinWire Ethernet 2-22
_2-20 Local Area VAXcluster 2-24
3-1 Settingthe Switch for ThinWire Ethernet 3-4
3-2 Connectingthe T-connector to ThinWire 3-5
3-3 Connectinga Terminator to the T-connector 3-6
3-4 Adding a Segment to the T-connector 3-6

3-5 Connecting the T-connector to VAXstation 2000 3-7 _
3-6 Connecting the T-connector to ThinWire 3-8
3-7 Connecting a Terminator to the T-connector 3-9
3-8 Adding a Segment to the T-connector 3-9
3-9 Attaching the T-connector to the DESTA 3-10
3-10
Attaching the Transceiver Cable to the DESTA 3-11
3-11 ThinWire Cables Connected to the DEMPR 3-13
3-12 Attaching aTerminator to a ThinWire Segment 3-14
3-13 Terminator Connected to the DEMPR 3-15
3-14 Connecting Two ThinWire Sections 3-16
Tables
2-1 Ordering Information for ThinWire Ethernet Cables 2-4
3-1 Formto Order ThinWire Equipment 3-3
VI

Preface
This manual describes how to configure and install some simple ThinWire
Ethernet networks for VAXstation 2000, MicroVAX2000, or VAXmate systems.
It doesnot describe all possible configurations, but outlinesthe rulesto follow
when configuring your network with ThinWireEthernet.
Recommended Reading Path
1. VAXstation 2000 Hardware Installation Guide, MicroVAX 2000 Hardware
Installation Guide, or VAXmate System Handbook. You should install your
VAXstation 2000, or VAXmate system before installing ThinWireEthernet.
2. Workstations and MicroVAX 2000 Network Guide, Chapter 2. This chapter
tells you how to configure your network.
3. Workstations and MicroVAX 2000Network Guide, Chapter 3. This chapter
describes how to install ThinWire Ethernet hardware on your system.
A glossary at the end ofthe book explains technical terms usedin this book.
Conventions
The following notices appear throughout this guide:
• Notes — Contain general or supplemental information about a topic.
• Caution — Contain information to prevent disruption of the network.
Convention
Meaning
Bold
Notes, cautions, and warnings are bolded.
Italics
Terms defined in the glossary are italicized the first
time the word appears in the text.
VII

Document Structure
This manual consists of three chapters and an appendix.
•Chapter 1 gives an overview of ThinWire Ethernet, defines networks, and
describes DECnet, ULTRIX networks, and VAXclusters.
• Chapter 2 describes the basic components you will need, some simple
configurations, and the rules for connecting to ThinWire Ethernet.
•Chapter 3 describes how to determine your needs and how to install and
troubleshoot a Thin Wire Ethernet network.
• Theappendixlistsassociated documents that mightbe helpfulin planning
your network.
VIII

^ Chapter 1
Overview
Networks are useful to people who need to work together and share
information but still want the attractive features of their own workstation.
People working cooperatively on a project may need to communicate and
exchange information, share common data bases, share files, or use a mail
system, and yet keep their workstation independent. Networks also allow
you to share devices, suchas laser printers or line printers.
What Makes a Network?
A network is a group of computers connected by communications lines to
share information and resources. You need special network hardware and
software to connect your network. DECnet software enables computers to
form a network.
Standard Ethernet
Ethernet is the DIGITAL local area network. Ethernetnetworks provide rapid
access to data in remote locations, and the high data rate supported by
DIGITAL'S DECnet software makes file transfers practical.
In baseband Ethernet (Standard or ThinWire), a single network cable replaces
the numerous interconnecting cables in traditional data networks. Standard
Ethernet cable is recommended for commimications between floors and
buildings. ThinWire cable is recommended for communications between
workstations, personal computers, and low-end systems in local work areas
on a floor.
ThinWire Ethernet
ThinWire is a networking cabling system and set of products that deliver 10
megabits-per-second Ethernet to the desk, work area, and local area systems
for connection of personal computers, workstations, network servers, and
low-end computing devices. All DIGITAL Ethernet products can connect to
ThinWire offering an alternative wiring approach for low-end, mid-range.
Overview 1—1

and high-end systems and Ethernet servers without any change in network
performance. , ^
ThinWire Ethernet is used in any size environment. It is ideal for a small
stand-alone network in which personal computer and workstation users
share resources, such as prmters and storage devices.
ThmWire works
well as a small- to medium-sized stand-alone local area network (LAN)
in a small business or in a department of a larger organization where
personal computer and workstation users need local resource sharing and
more powerful computing resources. A LAN isa high-speed communications
network that covers a limited geographical area, such as a section of a
building, an entire building, or a cluster of buildings.
Unshielded Twisted-Pair Ethernet
The Unshielded Twisted-Pair Ethernet Adapter delivers 10 megabits-per-
second Ethernet performance to the desktop, work area, and local system
over unshielded twisted-pair building cable.
Unshielded tvdsted-pair adapters connect a single device,
• DESTA with Micro VAX attached
• VAXmate
• VAXstation 2000
•Personal computer with DEPCA, DELUA, or DELQA Ethernet controllers
to the Ethernet network by means of the DIGITAL ThinWire Ethernet
Multiport Repeater (DEMPR). Small stand-alone local area networks, where a
personal computer and workstation usershare limited local resources (printers,
storage devices), can be connected as a subnetwork to large local area and
wide area networks.
Functionally, the office adapter and wiring closet/SER adapter work as a
pair to match the 50-ohm impedance on a ThinWire Ethernet coaxial cable
to the impedance on an unshielded twisted-pair cable. Thus, unshielded
tv«sted-pair building wiring can be used, in addition to ThinWire cable, to
run Ethernet to the desktop.
Unshielded Twisted-PairEthernet Adapters are compatiblewith the ThinWire
Ethernet products and IEEE 802.3 specificationsfor "Medium Attachment Unit
and Baseband Medium Specifications for Type 10 Base 2."
1 —2 Workstations and MicroVAX 2Q00 Network Guide

The maximum length of 24 AWG unshielded twisted-pair cable that can be
used between the office adapter and the wiring closet adapter is 50 to 70
meters (164 to 230 feet).
DECnet
DECnet, a software product that enables many DIGITAL computer systems
to form a network, is derived from a well-defined network architecture called
the DIGITAL Network Architecture (DNA). DNA, similar to the standard
International Standards Organization (ISO) communication architecture, is
the logical structure that provides a model for DECnet implementations.
DECnet provides:
• Task-to-task communications — allows programs executing in different
systems to exchange information.
• File transfer — supports the copyingof files among different systems.
•Remote file access — allows the user to read, write, delete, or modify
files on another system.
•Remote command file submission and execution —allows one computer
system to direct another system to execute commands and/or perform
tasks.
• Down-line loading — allows programs developed on a system with
appropriate peripherals and resources to be sent to another system, such
as a small, memory-only system, for execution.
• The network virtual terminal — gives a user cormection toaremote
system; the terminal operates as if it were connected to the remote
system.
• Network management — provides for monitoring and controlling network
operation in a distributed environment.
Networking Capabilities of ULTRIX
TCP/IP networking protocols are standard wth the ULTRIX-32 software.
They are an integral part of the operating system and facilitate interaction
with Internet networks. Support includes iMe transfer, remote execution,
remote login, and resource-sharing capabilities with other systems running
the TCP/IP protocols.
DECnet-ULTRIX provides an Ethernet-based communication link between
VMS and ULTRIX operating systems. ULTRIX bridgesboth environmentsby
supporting the coexistence of the DECnet and TCP/IP protocols. DECnet
Overview 1-3

and TCP/IP can run simultaneously and share the same system resoiwces,
such as the DEUNA and DEQNA Ethernet interfaces. This feature allows
a DECnet-ULTRIX system to act as an informal gateway between DECnet
networks and Internet networks. DECnet-ULTRIX allows ULTRIX to interact
with other DIGITAL and non-DIGITAL operating systems, using DECnet
products such as DECnet-RSX, DECnet-VAX, DECnet-DOS.
Local Area VAXclusters
The computer industry today provides individuals or small work groups in
organizations with their own personal computer systems or workstations,
solving the computing availability problem but creating a new set of
problems — managing large numbers of geographicaUy dispersed personal
workstations. Another problem for users is that they have inherited system
management responsibilities and need to have more knowledge of the
operating system to perform system management tasks.
The Local Area VAXcluster using ThinWire or standard Ethernet as the
interconnect allows
DIGITAL'S low-end VAX/MicroVAX products to be
grouped in similar VMS worksystems, removing the problems of system
management on a per node basis and elevates it. to a single system
management domain. Except for the interconnect-dependent driver software,
the same VAXcluster software is used on both Cl-based clusters and ThinWire
or standard Ethernet-based clusters.
The Local Area VAXcluster systemalsosolvesthe problemsofinadequatedisk
space and data sharing among members of a group or team. VAXclusters
provide distributed processing capabilities to allow load-sharing batch and
print processing across member nodes or to target a node, reducing the
amount of wasted or underutilized computes.
One other problem is MicroVMS has to be installed on every Micro
VAX or
VAXstation. In a LocalArea VAXcluster, the system requires no localsoftware
installation and can be plugged into a suitable ThinWire or standard Ethernet
connection and be remotely booted, removing the need for local software
installation.
Special software allows membership in a Local Area VAXcluster. This
software provides flexibility by allowing many Local Area VAXclusters to
share the same Ethernet or ThinWire Ethernet segment and to allow nodes to
logically move from pne cluster to another.
1-4 Workstations and MicroVAX 2000 Network Guide

Chapter 2
Setting Up the Network
This chapter describes the basic components you will need, some simple
topologies, and the rules for connecting a system to ThinWire Ethernet. This
chapter also describes how to set up your system to connect to standard
Ethernet.
Standard Ethernet
To use standard Ethernet on your VAXstation 2000, move the Ethernet switch
onthe back of the system unit to the down position (Figure 2-1).
Figure 2-1: Setting the Switch forStandard Ethernet
UNDERNEATH VIEW
BUTTON
ETHERNET
SWITCH
HALT
ICON
Setting Up the Network 2—1

Locate the Ethernet intermediary cable (part no. 1701860-01) that comes
with your system unit. Connect it to the back of the system unit as shown
in Figure 2-2.
Figure 2-2: Connecting the Intermediary Cable
INTERMEDtARV
ETHERNET
CABLE
Refer to the DECconnect documentation for more information on connecting
your system to standard Ethernet.
Basic ThinWire Components
The Ethernet Module contains a transceiver that allows you to connect your
system to ThinWire Ethernet. The Ethernet Module is preinstalled in all
VAXstation 2000 and VAXmate systems. If you want to connect a Micro VAX
2000 system to ThinWire Ethernet, order the Ethernet Module preinstalled or
contact field service to install the module.
The Ethernet Module equipment consists of the following:
• One Ethernet Module
• Two terminators
• One T-connector
2—2 Workstations and MicroVAX 2000 Network Guide

Contact your DIGITAL representative to order ThinWire cable lengths with
connectors at each end.
If you prefer, you can purchase ThinWire Ethernet cable on a Ispool and cut
the cable to your needs. See the VAXstation 2000/MicroVAX 2000 Maintenance
Guide for information on cutting and crimping ThinWire Ethernet cable.
Before reading about configurations, you need to know the following terms:
•Station — A single addressable device on a Local Area Network; for
example, a VAXstation 2000, Micro VAX 2000, or VAXmate.
•Section — A single continuous piece of coaxial cable.
• Segment — Any number of ThinWiresections joined by barrel connectors
or T-connectors to form a single, continuous cable.
ThinWire Ethernet Cable
ThinWire Ethernet cable has a jacket of either polyvinyl chloride (PVC) or
Teflon. Either PVC or
Teflon cable can be used in an open office area.
However, in the Uruted States, Teflon may be required for areas classified
by the Underwriter's Laboratory (UL) as environmental air spaces, such as
in air-conditioning ducts or air plenum. An air plenum is a compartment or
chamber to which one or more compartments are connected in a building
ventilation system and is only used for carrying envirorunental air. Check
your local building codes for more information.
ThinWire Ethernet cable delivers 10 megabits-per-second performance and
full Ethernet functionality.
The maximum length of a segment is 185 m (606 ft).
ThinWire Ethernet products adhere to the IEEE standard 802.3. ThinWire
Ethernet products are compatible with products that conform to this
international standard. ThinWire Ethernet cable is:
• Flexible
• Fully compatible with standard Ethernet
•Inexpensive
• High performance
Sening Up the Network 2-3

You can order ThinWire Ethernet cables in the following cable lengths:
Table 2-1: Ordering Information for ThinWire Ethernet Ca-
bles
Order No. Description
BC16M-06 ThinWire Cable, PVC, 6'
BC16M-15 ThinWire Cable, PVC, 15'
BC16M-30 ThinWire Cable, PVC, 30'
H8243-A ThinWire Cable, PVC, 1000' spool
H8244-A ThinWire Cable, Teflon, 1000' spool
Figure 2-3 shows the ThinWire Ethernet cable.
Figure 2-3: ThinWire Ethernet Cable
2-4 Workstations and MicroVAX 2000 Network Guide

Connectors and Terminators
The ThinWire connectors andterminators youneedto configure your network
follow:
• T-connector (H8223) — A 3-way connector that joins two ThinWire
Ethernet cable sections. Thethird opening attaches to a VAXstation 2000,
MicroVAX 2000, or aVAXmate system.
• Terminator (H8225) — A cormector at the end of a ThinWire segment
that provides the 50-ohm termination resistance needed for the cable. If
the ThinWire cable connects to a DIGITAL ThinWire Ethernet Multiport
Repeater (DEMPR), then a terminator is only needed at one end of the
cable.
• Barrel connector (H8224) — A recessed connector that connects two
ThinWire Ethernet cable sections.
Figure 2-4 shows the connectors you need to connect to ThinWire Ethernet.
Figure 2-4: Connectors
CONNECTOR
s
BARREL
CONNECTOR
T-CONNECTOR
CONNECTOR
Setting Up the Network 2-5

Additional Equipment
Use the following equipment for additional configurations:
• DIGITAL ThinWire Ethernet Multipart Repeater(DEMPR-AA)
• DIGITAL ThinWire Ethernet StationAdapter (DESTA-AA)
•Ethernet Bridges (DEBET-AA)
DIGITAL ThinWire Ethernet Multiport Repeater (DEMPR)
A DEMPR is a repeater, a device used to extend the length, topology, or
intercormection of the physical network medium beyond the limits imposed
by a single segment.
You can connectup to eight ThinWire Ethernet segments to a single DEMPR
to form a single LocalArea Network. Or, you can connect a ThinWire LAN
to standard Ethernet through the
DEMPR. Eachsegment can have 29 stations
(the 30th position is taken by the DEMPR) for a total of up to 232 stations.
Figure 2-5 shows the DEMPR.
The DEMPR offers:
•Support of up to eight ThinWire Ethernet connections
•Support of multiple Ethernet devices for each connection
• Easy installation
Figure 2-5: DIGITAL ThinWire Ethernet Multiport Repeater (DEMPR)
MLO-1321-87
2-6 Workstations and MicroVAX 2000 Network Guide

DIGITAL ThinWire Ethernet Station Adapter (DESTA)
The DESTA is an Ethemet/BEEE 802.3 transceiver that connects systems
(such as the Micro VAX II, VAXstation II, VAXstation II/GPX, VAX 11/7XX,
VAX/8XXX, Professional 300, and PDP-11) to ThinWire Ethernet. (A
transceiver is a device that provides a single physical connection betweerii
standard Ethernet and Ethernet communication equipment.)
The DESTA has two ports: one port connects to the T-connector connected to
ThinWire, a second port connects a transceiver cable that leads to a system.
Figure 2-6 shows a DESTA.
The DESTA provides:
• Connection ofa system with a transceiver cable to ThinWire Ethernet.
• Attachment to devices connected to Ethernet communication controllers
by way of transceiver cables.
Figure 2-6: DIGITAL ThinWire Ethernet Station Adapter (DESTA)
M.O-1322-87
Sening Up the Network 2-7

DEBETs — The Ethernet Bridge
Ethernet bridges (DEBET) connect standard Ethernet LANs to each other, thus
creating an extended LAN. An extended LAN configuration has the potential
to span a much greater area than a single standard Ethernet LAN.
DEBETs provide network traffic control to prevent an extended LAN from
being overwhelmed by the combined traffic on each of its standard LANs.
DEBETs confine local traffic in a standard Ethernet LAN. Only traffic that is
destined for another standard LAN is allowed to cross over the DEBET.
ThinWire Configurations
A ThinWire configuration is an economical way to connect VAXstation 2000s,
Micro
VAX 2000s, or VAXmates in a network configuration.
Figure 2-7 shows the symbols for cables used in the ThinWire configurations
in this section of the book.
Figure 2-7: Symbols for Cables
STANDARD ETHERNET COAXIAL CABLE
THINWIRE ETHERNET COAXIAL CABLE
TRANSCEIVER CABLE
MLO-1323-87
Three ways to design a ThinWire configuration are:
1. DECconnect approach
2. Daisy-chain wiring approach
3. Combined DECconnect and Daisy-chain approach
2-8 Workstations and MicroVAX 2000 Network Guide