3Com 3C16593A Scheda tecnica - Pagina 2

Sfoglia online o scarica il pdf Scheda tecnica per Interruttore 3Com 3C16593A. 3Com 3C16593A 12. Superstack ii baseline hubs and switches
Anche per 3Com 3C16593A: Manuale d'uso (8 pagine)

Stampa la pagina

Hubs

Hubs are the most basic building

blocks for connecting together your

PCs, servers, and peripherals to form

a network. Sometimes referred to as

repeaters, hubs allow the attached

network devices to communicate with

each other and share information.

Connections to hubs are often referred

to as shared media connections, such as

shared 10 or shared 100, as opposed to

switched connections.

There are two types of hub in

the SuperStack II Baseline family:

The Baseline Hub, which

communicates with other network

devices at a speed of 10 Mbps;

The Baseline Dual Speed Hub,

which is capable of communicating

with other network devices at up

to 100 Mbps.

Both are available in 12- and 24-port

variants.

The right choice for you will depend

on the performance you need and the

speed at which your network devices

are capable of running. If some of your

PCs, servers, and network peripherals

are capable of running at 100 Mbps,

you will benefit from the tremendous

performance increase of the Baseline

Dual Speed Hub.

According to ISO/IEEE standards,

there is a limit to the number of hubs

that can be connected in series.

For 10 Mbps, the limit is four; for

100 Mbps, the limit is two.

Switches

Why would you need a switch?

Although they provide the same

connectivity for your network cables

as hubs, switches give you far superior

network performance. They do this by

increasing the network's available data

bandwidth (the maximum capacity of

the network for moving data). Instead

of sharing the total available bandwidth

among all connected users, as a hub

does, a switch gives each attached

network device its own dedicated

amount of bandwidth.

For example, any 10 Mbps hub

will offer 10 Mbps of bandwidth to

be shared among all devices attached

to it. An equivalent switch will offer

10 Mbps of bandwidth for exclusive use

by each attached device. Performance

will be much faster. It is further

increased if the switch supports full-

duplex links like the Baseline switches.

Switches operate by learning the unique

MAC address of each network device on

your LAN, and by knowing which port

each one is connected through.

There are two types of switches in the

SuperStack II Baseline family:

The Baseline Switch communicates

with other network devices at a

speed of 10 Mbps, and has two

10/100 Mbps links capable of run-

ning at 100 Mbps for fast links to

servers or the network backbone;

The Baseline 10/100 Switch,

is capable of communicating

with other network devices at up

to 100 Mbps on all ports for the

ultimate in high-speed connectivity.

Both are available in 12- and 24-port

variants.

Switches are most suited to certain

applications:

Near the core of the network,

they eliminate bottlenecks and

improve the overall network

throughput;

They can extend the span of a

network that has the maximum

allowed hubs connected in series;

When used as a desktop

connectivity device, they provide

the highest possible performance

for connecting users to your

network.

10/100 Mbps

(Dual Speed) Operation

Today, more and more PCs, servers,

and network peripherals that you buy

have the capability to connect to either

a 10 Mbps or 100 Mbps network link.

They can operate up to 10 times the

speed of traditional 10 Mbps links as

long as the hubs or switches they are

connected to can support 100 Mbps

operation. Why waste this latent

performance by connecting them

to a network device running at only

10 Mbps?

Your concern might be that you have

some older PCs, printers, or peripherals

that have a 10 Mbps-only network

connection. You will probably not

want to upgrade all of these at once to

connect to 100 Mbps hubs or switches.

In fact, some of your legacy devices may

not upgrade from 10 Mbps.

So, how can you connect some

devices into your hubs and switches

at 10 Mbps and some at 100 Mbps?

How do you ensure that you don't

connect them at the wrong speed?

By using a dual-speed hub or a switch

with 10/100 Mbps links on every port,

they will communicate with connected

equipment at either 10 Mbps or

100 Mbps as appropriate.

After installing a dual-speed hub

or a 10/100 Mbps switch, you can

gradually and seamlessy migrate

your network to run at 10 times the

speed! You can add newer, high-speed

network devices or upgrade your

existing equipment as the need

arises (and your budget allows).

The SuperStack II Baseline family

includes:

The Baseline Dual Speed Hub; and

The Baseline 10/100 Switch

Both are autosensing. They will link up

with your network users at 100 Mbps, if

possible, otherwise, they will instantly

and automatically revert to running at

10 Mbps. They always ensure that your

network runs as fast as your users are

capable. There's no need to worry about

patching a PC or a server to a hub or

switch at the wrong speed—and no

need to worry about whether you're

wasting valuable network bandwidth.