Got Connection?31 Dec, 1969 By: Sue Krautbauer imageSource
all over the news. You can’t help but know we are part of a ‘connected’
world these days. Everyone is talking about the Internet, SAN, LAN, ASP,
wireless and that they’re changing the face of our industry - right? What do
all these acronyms mean, and what do they stand for? Well, they are all
different forms of computer networks. Maybe you have one (is it common for you
to hear people say: “No email today, or the network's down, and “No Internet
today - the router isn't working”). Perhaps you aren’t on a network yet, but
your clients are, and they are looking to you to be the technical expert.
Furthermore, you may be wondering, “What exactly a network is?”
In the simplest terms, a network consists of two or more computers that are
connected together to share information. All networking, no matter how complex,
builds off this simple system. Although, this may seem like a basic idea, the
concept was a major achievement in communications.
What Makes Up A Network?
have a network you typically have four things (besides the computers
- a set of communication rules to make
sure that everyone speaks the same language.
interface cards (NICs) - cards that plug
into the back or side of your computer allowing them to send, and receive
messages from other computers.
- the medium to connect all of the
- hardware to perform traffic control.
The keyword is typically. Wireless networks obviously don't use
cables, and NICs aren't necessary for small networks that use parallel/serial
ports, but the basics still apply).
How Does A Network Work?
How does one computer send information to another? It is actually rather simple.
The diagram below shows a simple network:
If Computer A wants to send a file to Computer B, the following would take
on a protocol that both computers use, the NIC in Computer A translates the
file (which consists of binary data -- 1's and 0's) into pulses of
pulses of electricity pass through the cable with (hopefully) minimum
hub takes in the electric pulses and shoots them out to all of the other
B's NIC interprets the pulses and then decides if the message is for it or
not. In this case it is. Then Computer B's NIC translates the pulses back
into the 1's and 0's that make up the file.
Sounds easy, however, if anything untoward happens along the way, you have a
problem, not a network. So, if Computer A sends the message to the network using
a Microsoft protocol, but Computer B only understands the TCP/IP
protocol, it will not understand the message, no matter how many times Computer
A sends it. Computer B also won't get the message if the cable is getting
interference from the fluorescent lights, or if the network card has decided not
to turn on today, etc.
snowflakes, no two networks are ever alike. Therefore, it helps to classify them
by some general characteristics for discussion. A given network can be
characterized by the following:
The geographic size of the network.
and Access: Who can access the network? How is access controlled?
The rules of communication in use on it (ex. TCP/IP, NetBEUI, AppleTalk,
The types of physical links and hardware that connect the network
(LANs and WANs): Regarding size, networks are generally lumped into two
categories, local area networks (LANs), and wide area networks (WANs).
LAN is primarily defined by geography, and is typically housed in one building
or campus. A WAN, on the other hand, is a network that joins many LANs together
using super special, highly secret, WAN technologies (we will delve into that
arena some other day. I hope that you are still reading on.) Because LANs
are so common, they are usually further divided into two major types, which are:
peer-to-peer network doesn't have any dedicated servers or hierarchy among the
computers. All of the computers on the network handle security and
administration for themselves. The users must make the decisions about who gets
access to what. For more information on this feature see article Networking 101:
client-server network works the same way as a peer-to-peer network, except that
there is at least one computer that is dedicated as a server. The server stores
files for sharing, controls access to the printer, and generally acts as the
dictator of the network. For more information, see article Networking
101: Client-Server Networks.
As stated above, the protocol of a network is the set of guidelines for
inter-computer communication. Two computers with different protocols won't be
able to communicate with one another (imagine Ralph Nader and Pat Buchanan in
the same room). While many computers have the ability to interpret multiple
protocols, it is important to understand the different protocols available
before deciding on one that is appropriate for your network.
While some, theoretically minded people would claim that the hardware involved
in a network isn't extremely important; they probably haven't ever actually
dealt with setting up one. Hardware is important. While in theory, every hub
should send and receive signals perfectly, that isn't always the case. Moreover,
the problem is that if you ask two network administrators what hub they
recommend, you will probably get two entirely different, yet passionate answers.
From picking the cable (optical fiber, coaxial, or copper), to choosing a
server, you should find the most suitable hardware for your needs.
Up Next Month
will take you through what are considered the industry norms for computer
network hardware, software, and maintenance, as well as the typical offerings
that your customers expect from their computer services vendor.