This lesson covers the very basics of networking. We’llstart 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: essentiallythe 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 withmuch of the vocabulary you hear with regards to networking. Some of these conceptsare covered in more detail in later lessons
-1960's- 1970's Communication
-Hownetworks are growing
-Howa LAN Is Built
From a historical perspective, electronic communication hasactually 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 BaltimoreMD, 37 miles away. The message? “What hath God wrought.”
Less than 25 years later, Alexander Graham Bell invented thetelephone – beating out a competitor to the patent office only by a coupleof hours on Valentine’s Day in 1867. This led to the development of theultimate analog network – the telephone system.
The first bit-oriented language device was developed by EmileBaudot – the printing telegraph. By bit-oriented we mean the device sentpulses of electricity which were either positive or had no voltage at all. Thesemachines did not use Morse code. Baudot’s five-level code sent five pulsesdown the wire for each character transmitted. The machines did the encoding anddecoding, eliminating the need for operators at both ends of the wires. For thefirst time, electronic messages could be sent by anyone.
But it’s really the telephone network that has had thegreatest impact on how businesses communicate and connect today. Until 1985, theBell Telephone Company, now known as AT&T, owned the telephone network fromend to end. It represented a phenomenal network, the largest then and still thelargest today.
Let’s take a look at some additional developments in the communicationsindustry that had a direct impact on the networking industry today.
Developments in Communication
In 1966, an individual named “Carter” inventeda special device that attached to a telephone receiver that would allow constructionworkers to talk over the telephone from a two-way radio.
Bell telephone had a problem with this and sued – andeventually lost.
As a result, in 1975, the Federal Communications Commissionruled 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. Infact, years ago you could look at the underside of a telephone not manufacturedby Bell, and see the “Part 68” stamp of approval.
This ruling eventually led to the breakup of American Telephoneand Telegraph in 1984, thus creating nine regional Bell operating companies likePacific Bell, Bell Atlantic, Bell South, Mountain Bell, etc.
The break up of AT&T in 1984 opened the door for other competitors in thetelecommunications market. Companies like Microwave Communications, Inc. (MCI),and Sprint. Today, when you make a phone call across the country, it may go throughthree or four different carrier networks in order to make the connection.
Now, let’s take a look at what was happening in the computerindustry about the same time.