10Base-T/2/5/F/35 - Ethernet
Introduction
The 10Base-T UTP Ethernet and 10Base-2 Coax Ethernet
were very popular around the early to mid 1990's when 100Mbit network
cards and hubs/switches were very expensive. Today's prices have dropped
so much that most vendors don't focus on the 10Base networks but the
100Base ones and, at the same time, support the 10 BaseT and 10Base-2
standard. We will also talk about the 10Base5/F and 35 shortly.
So what does 10 BaseT/2/5/F/35
mean ?
To make it simpler to distinguish cables they are categorised;
that's how we got the CAT1, 2, 3 etc cables. Each category is specific
for speed and type of network. But since one type of cable can support
various speeds, depending on its quality and wiring, the cables are
named using the "BaseT"
to show exactly what type of networks the specific cable is made to
handle.
We are going to break the "10
Base T (and
the rest) " into 3 parts so we can make
it easier to understand:
10
The number 10 represents the frequency in MHz (Mega
HertZ) for which this cable is made. In this case it is 10 MHz. The
greater the MHz, the greater speeds the cable can handle. If you try
to use this type of cable for greater frequencies (and, therefore,
speeds) then it either will not work or become extremely unreliable.
The 10 MHz speed translates to 10Mbit per second,
which in theory means 1.2 MBytes per second. In practice
though, you wouldn't get more than 800 KBytes per second.
Base
The word "Base" refers to Baseband. Baseband
is the type of communication used by Ethernet and it means that when
a computer is transmitting, it uses all the available bandwith, whereas
Broadband (cable modems) shares the bandwidth available. This is the
reason cable modem users notice a slowdown in speed when they are
connected on a busy node, or when their neighbour is downloading all
the time at maximum speed ! Of course with Ethernet you will notice
a slowdown in speed but it will be smaller in comparison to broadband.
T/2/5/F/35
The "T" refers to "Twisted Pair"
physical medium that carries the signal. This shows the structure
of the cable and tells us it contains pairs which are twisted. For
example, UTP has twisted pairs and this is the cable used in such
cases. For more information, see the "UTP
-Unshielded Twisted Pair" page where you can find information
on pinouts for the cables.
10Base-T
A few years ago, the 10
BaseT cables used CAT3 cables, which are used for speeds
up to 10Mbit, but today you will find mostly CAT5 cables, which are
good for speeds up to 100 Mhz or 100Mbit, these cables are also used
for 10Mbit networks. Only 2 pairs of the UTP cable are used with the
10Base-T
specification and the maximum length is 100 meters. Minimum length
between nodes is 2.5 meters.
10Base-2
This specification uses Coaxial cable which is usually
black, sometimes also called "Thinwire coax", "Thin
Ethernet" or "RJ-58" cable. Maximum length is 185 meters
while the minimum length between nodes is 0.5 meters. 10Base-2 uses
BNC connectors which, depending on the configuration, require special
terminators. The 10Base-2 specification is analysed
here in great detail (also contains pictures) if you wish to read
more about it.
10Base-5
This specification uses what's called "Thickwire"
coaxial cable, which is usually yellow. The maximum length is 500
meters while the minimum length between nodes is 2.5 meters. Also,
special connectors are used to interface to the network card, these
are called AUI (Attachment Unit Interface) connectors and are similar
to the DB-15 pin connectors most soundcards use for their joystick/MIDI
port.
Most networks use UTP cable and RJ-45 connectors or
Coaxial cable with BNC "T" connectors, for this reason special
devices made their way to the market that allow you to connect an
AUI network card to these different cable networks.
The picture below shows you a few of these devices:
10Base-F
This specification uses fibre optic cable. Fibre optic
cable is considered to be more secure than UTP or any other type of
cabling because it is nearly impossible to tap into. It is also resistant
to electro magnetic interference and attenuation. Even though the
10Base-F specification is for speeds up to 10Mbits per second, depending
on the type of fibre and equiptment you use, you can get speeds of
up to 2Gigabits per second !
10Base-35
The 10Base-35 specification
uses broadband coaxial cable. It is able to carry multiple baseband
channels for a maximum length of 3,600 meters or 3.6 Kms.
Summary
To summarise, keep the following in mind:
