3COM 3C16751 User Manual

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FFICECONNECT

O

FFICECONNECT

3C16751

3C16751

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®

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UAL

UAL

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PEED

PEED

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UB

UB

16

16

Part No.
DUA1675-1AAA01

Published
August 1998

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I

NTRODUCTION

Welcome to the world of networking with 3Com®.

In the modern business environment, communication
and sharing information are crucial. Computer
networks have proved to be one of the fastest modes
of communication. The OfficeConnect
range from 3Com brings the power of computer
networks to the small office.

The OfficeConnect Dual Speed Hub 16 is an
easy-to-use Class II hub (repeater) with 16
10/100BASE-TX ports. It allows you to set up a
network with both Ethernet (10Mbps) and Fast
Ethernet (100Mbps) workstations and other devices
(a Class II hub can be connected to another Fast
Ethernet hub, a Class I hub cannot).

When referring to the OfficeConnect Dual Speed
Hub 16, this guide uses the term ‘Hub’.

Each port on the Hub can be connected to either a
10BASE-T (Ethernet) or a 100BASE-TX (Fast Ethernet)
device. The port senses the speed of the connected
equipment and operates at the appropriate speed.

If you wish to extend an existing Ethernet network
into Fast Ethernet, adding a Dual Speed Hub 16 can
offer a more cost-effective migration path than
adding both a 100Mbps hub and a 10/100Mbps
switch.

®

product

Small Network with OfficeConnect Dual Speed Hub 16

The Hub is ideal for use with other OfficeConnect
products. The OfficeConnect product range is
compact and attractively designed for desktop use,
and neatly stacks together with clips. For further
information, refer to the “OfficeConnect Product
Range” sheet that accompanies the Hub.

This guide helps you get the most out of your Hub.

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REATING

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ETWORK

Networking Terminology

A

Network

A

Local Area Network (LAN)

Ethernet

Fast Ethernet

10BASE-T

100BASE-TX

is a collection of workstations (for example,
IBM-compatible PCs) and other equipment (for
example, printers), connected for the purpose of
exchanging information or sharing resources.
Networks vary in size; some are within a single room,
others span continents.

is a network, usually in an

office, that spans no more than a single site.

is a type of LAN, referring to the technology used
to pass information around the network. It operates
at 10Mbps (megabits per second).

is a type of LAN that runs up to 10 times
faster than standard Ethernet. It operates at
100Mbps.

is the name given to the Ethernet protocol that

runs over

that runs over

Twisted Pair (TP)

is the name given to the Fast Ethernet protocol

Twisted Pair (TP)

cable at 10Mbps.

cable at 100Mbps.

A

Network Loop

A

Segment

Packets

Bandwidth

In a

2

occurs when two pieces of network

equipment are connected by more than one path.

is the length of cable connected to a port.

are the units of information your workstations and
other equipment send to each other over the
network. A
can be
(sent to multiple devices), or
devices).

network can hold at any one time (information
capacity) measured in
Workstations or applications that use the network
heavily are referred to as using high bandwidth (these
are usually users who do a lot of graphical or
multi-media work across the network). Fast Ethernet
has a higher bandwidth than Ethernet, so it can cope
with larger amounts of traffic, which results in faster
operation.

Half Duplex

direction, but not in both directions simultaneously.

Unicast

refers to the amount of network traffic the

link, information can flow in either

is the data part of the packet and

Frame

(sent to a single device),

Broadcast

bits per second (bps)

Multicast

(sent to all

.

Before You Start

Using the Rubber Feet and Stacking Clips

Your OfficeConnect Dual Speed Hub 16 comes with:
One power adapter for use with the Hub



One power cord



A Warranty Registration card for you to fill out and



return
Four rubber feet



Four stacking clips



An OfficeConnect Product Range sheet



An OfficeConnect Network Assistant CD-ROM



This guide



Workstation Connections

To connect workstations or other equipment (such as
servers) to your Hub, you need:

One 10BASE-T,

1

10/100BASE-TX, or
100BASE-TX adapter card
for each workstation.
3Com produce a range of
easy to install network
adapters, which provide
your workstation with a
suitable connection.

One suitable TP cable for each workstation.

2

In order to comply with the 10BASE-T standard, ports
designed for workstation connections have been
marked with the graphical symbol ‘X’. This denotes a
crossover in the port’s internal wiring, for example
1X, 2X, 3X...

You also need a network operating system running
on your workstations.

The four self-adhesive rubber feet prevent your Hub
from sliding around on your desk. Stick the feet to
the marked areas at each corner of the underside of
your Hub.

The four stacking clips are used for neatly and
securely stacking your OfficeConnect units together.

You can stack up to four units. Small units must
be stacked above large units.

To stack your units,
secure the clips on one side and then on the other.
Use the following method to secure one side:

Place your new unit

1

on a flat surface.
Your clips fit in these
positions on the side
of the unit:

Position a clip over

2

one of these holes and
push it in until it clicks
into place. Repeat this
for the other clip
position on the same
side.

Twisted Pair (TP) Cables

To connect your workstations and other equipment to
the Hub, use ‘straight-through’ TP cables with RJ45
connectors (all OfficeConnect products use RJ45 type
connectors). A ‘straight-through’ cable is one where
each pin of one connector is connected to the same
pin of the other connector.

Cables can be shielded (screened) or unshielded; we
recommend that you use shielded cable. Cables used
for 100BASE-TX or 10/100BASE-TX connections must
be data grade (Category 5).

Your supplier should stock suitable cables.

The maximum length of a single cable is 100m
(328ft). Refer to “Fast Ethernet (100Mbps)
Configuration Rules” on page 5 for further
information on cable lengths in a 100Mbps network.

Hub Connections

To connect other OfficeConnect units to your Hub,
you need one suitable TP cable for each unit.

Keeping the front of

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the units aligned, rest
the bottom of the
existing unit on the
clips’ spikes. Push the
clips firmly into the
existing unit until they
click into place.

Repeat these steps to secure the other side.

To remove a clip, hold the units firmly with one hand
and hook the first finger of your other hand around
the back of the clip. Use reasonable force to pull it off.

3