Lesson 1: Networking Basic
This lesson covers the very basics of networking. We’ll
start with a little history that describes how the networking
industry evolved. We’ll then move on to a section that
describes how a LAN is built: essentially the necessary components
(like NIC cards and cables). We then cover LAN topologies.
And finally we’ll discuss the key networking devices:
hubs, bridges, switches, and routers.
This module is an overview only. It will
familiarize you with much of the vocabulary you hear with
regards to networking. Some of these concepts are covered
in more detail in later lessons
The
Agenda
- Networking
History
- How
a LAN Is Built
- LAN
Topologies
- LAN/WAN
Devices
Networking History
Early networks
From a historical perspective, electronic
communication has actually been around a long time, beginning
with Samuel Morse and the telegraph. He sent the first telegraph
message May 24, 1844 from Washington DC to Baltimore MD, 37
miles away. The message? “What hath God wrought.”
Less than 25 years later, Alexander Graham
Bell invented the telephone – beating out a competitor
to the patent office only by a couple of hours on Valentine’s
Day in 1867. This led to the development of the ultimate analog
network – the telephone system.
The first bit-oriented language device was
developed by Emile Baudot – the printing telegraph.
By bit-oriented we mean the device sent pulses of electricity
which were either positive or had no voltage at all. These
machines did not use Morse code. Baudot’s five-level
code sent five pulses down the wire for each character transmitted.
The machines did the encoding and decoding, eliminating the
need for operators at both ends of the wires. For the first
time, electronic messages could be sent by anyone.
Telephone Network
But it’s really the telephone network
that has had the greatest impact on how businesses communicate
and connect today. Until 1985, the Bell Telephone Company,
now known as AT&T, owned the telephone network from end
to end. It represented a phenomenal network, the largest then
and still the largest today.
Let’s take a look at some additional developments in
the communications industry that had a direct impact on the
networking industry today.
Developments in Communication
In 1966, an individual named “Carter”
invented a special device that attached to a telephone receiver
that would allow construction workers to talk over the telephone
from a two-way radio.
Bell telephone had a problem with this and
sued – and eventually lost.
As a result, in 1975, the Federal Communications
Commission ruled that devices could attach to the phone system,
if they met certain specifications. Those specifications were
approved in 1977 and became known as FCC Part 68. In fact,
years ago you could look at the underside of a telephone not
manufactured by Bell, and see the “Part 68” stamp
of approval.
This ruling eventually led to the breakup
of American Telephone and Telegraph in 1984, thus creating
nine regional Bell operating companies like Pacific Bell,
Bell Atlantic, Bell South, Mountain Bell, etc.
The break up of AT&T in 1984 opened the door for other
competitors in the telecommunications market. Companies like
Microwave Communications, Inc. (MCI), and Sprint. Today, when
you make a phone call across the country, it may go through
three or four different carrier networks in order to make
the connection.
Now, let’s take a look at what was
happening in the computer industry about the same time.
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