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,
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
- 1970's Communication
networks are growing
a LAN Is Built
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.
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
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
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.