Computer Networking

Connecting two or more computers together is called networking. You might want to 
network computers for several reasons: Communications between the operators at 
each computer, file sharing, file transfer, printer sharing, or using a common 
database on major programs.

Dispite what you might think, Networking is not a simple operation. Thought must
go into what you are trying to accomplish and how you are going to do it, and more
importantly, how you are going to safegard your files you create and use. This 
includes not only backing up data, but protecting it from being overwritten by another
computer user on the network.
 
The actual connection between two computers can be as simple as a "null modem" cable
on the serial, parallel, or USB ports. If you need to expand beyond 2 computers, this
is a poor choice. A best way to connect computers is by network cards in each computer.
Cards are relatively cheap these days. A "hub" is required to link all computers together
and they are relatively inexpensive unless you have special requirements.

Networking requires hardware: cards, cables, hubs, etc, as well as software to make the
computers pass information. It may require special networking versions of programs you
intend to use. Plan which expansion cards you need for each computer. There are cards for
the older ISA bus as well as the newer PCI bus. Make sure everything is compatible. 
Note book computers require "PCMCIA" cards or "PC Cards".

There have been several networking technologies over the years including ARCNET and
proprietary cards (DNA, Invisible Net, Lantastic, etc) and software. Novell, once a
strong standard (and very expensive), has fallen to Windows networking protocol, usually
NETBUI or TCP/IP. This is built into "Windows for Workgroups", Windows 95/98/Me, NT, and
2000. Novell usually required a systems engineer to install it and on call at all times.
Windows NT/2000 Server still requires a specialist to install it and maintain it.

Ethernet, 10 Base T, has been the most common for some time. A newer and faster variation
called 10/100 is compatible and increasing in popularity. Ethernet uses 4 pair twisted
cable rated Catagory or CAT 5. Connectors are RJ45, similar (but bigger) to modular 
phone connectors.

Computers that are simply linked together are called peer to peer. This can be a very 
dangerous situation because users loose files because someone else copied over them. It
is best to have a "server" that stores "the database" and everyone shares the same data.
A server has one purpose, to serve all other computers. No one should use it as a
workstation. This is to protect it from accidental human errors that may bring down a
whole system. Only required software is installed to a server. Servers should be placed
in a separate room, away from curious fingers. That room should be ventilated and 
temperature kept no more than 75 degrees. Servers should also be placed on a UPS or
Uninteruptable Power Supply.

There are networking versions of software that provide protection called file locking.
If you have a sensitive database, you should pay the additional cost. It is possible to
overwrite files on a server without this protection. Some programs simply won't work on
a network until you purchase the "networking version". Others will crash when networked.

An example is user #1 goes into a database and adds 10 new customers. User # 2 also goes 
into the database during part of the same time and adds 15 different customers. The last 
one to save the data will override the other and only the last user's data will actually
be saved. 

A business may experience serious consequences if it is not planned and set up properly. 
For this reason, you should hire a responsible network specialist to install it and 
maintain it. There are Certified Windows Network Engineers who are trained to do this. 
Because of this, most CNE's charge between $150 to $200 per hour for installation and 
support. A network using a server and NT will require continuous support.

Networks can extend thru large office buildings and between buildings. They can even 
stretch across town or country. Networks between buildings require extensive protection 
against induced electrical interference or lightning pulses. Phone connections across 
town or country also require special costly considerations including security, surge 
protection, interfacing, and software considerations. It is best to use fiber optic 
cable or wireless (802.11B/WiFi) between buildings to reduce risk of surge or lightning 
damage. 

A reliable backup plan and system is an absolutely necessity. It should include an
image to restore the whole drive quickly as well as a data backup to replace timely
data changes (daily). Your plan should include rotation of backup media as well as
an off-site copy. In some cases of mission critical situations, even a backup computer
ready to serve may be necessary. Your plan should include contingincys for fire, theft,
flood, and failure.

Many companies rely on data, reports, and other information to keep their companies 
running. Customer lists, accounting information, and scheduling are critical to many 
companies. If the computer goes down, the company stops. Make sure your computer or network
doesn't take you down. 
 
                               Gene's Computer Outlet
                                 Copyright 1995-2001

                                Basic Steps to set up:
Install cards in each computer
Install driver for NIC
Connect each computer to the hub
In Control Panel: Install NETBUI
                  Make sure there is binding: NETBUI to network card
                  Turn on file sharing 
In My Computer:   Right Click on C and allow sharing
Reboot computer
Network Neighborhood: Should see other computers