How Intranets
& Extranets Work
I
ntranets and extranets are becoming increasingly popular as a way to distribute information and foster communication and collaboration in medium-to-large companies. They combine the advantages of using existing network infrastructure as a communication medium and the
ease of use that has made the Web such a hot item.
Intranet and extranet sites reside on dedicated servers in
the form of HTML (Hypertext Markup Language) and
other Web-native formats, and users can access them with
Web browser software (like Internet Explorer) that most
network PCs already have.
Intranets are extremely versatile; companies use
them to accomplish myriad tasks that in the past
required stacks of paper and, in most cases, considerably
more time. Human resource departments can give company employees quick, easy access to documents like
status change forms and vacation request forms, and can
pass on benefits information or post information about
new company positions. Marketing departments can distribute sales brochures, product data, and promotional
information, and companies can provide their business
Compiled by Chris Trumble
Graphics & Design by Andria Schultz
partners (suppliers, resellers, manufacturers, etc.) with
the information they need using extranet sites.
There are as many different ways to configure an
intranet or extranet as there are companies, depending
on the size of the organization and what it wants its
intranet to do. This illustration shows a company with
three offices sharing intranet content via company
LANs, leased fiber-optic lines, and the Internet. It also
demonstrates how companies can share information
with suppliers using an extranet and the public
Internet. Most companies use one type of connection or
the other, although we're displaying both for the sake
of demonstration.
1
Intranet Page
2
Intranet Server
Best Bread Company:
Chicago location
LAN
Firewall
Extranet Server
3
Intranet Page
Best Bread
Company:
Dallas location
Company’s leased line
LAN
Intranet
1
2
Best Bread has a company-wide intranet
that originates from its main office in
Chicago. The Dallas location is connected
to the company WAN (wide area network)
and its intranet through a leased highspeed fiber connection that eliminates the
need for encryption and other types of
security. Some companies avoid the cost
of leasing special lines by extending their
intranets across the public Internet, as
shown in the example Best Bread's Los
Angeles office. Such connections typically
Intranet Page
Public Internet
LAN
Extranet
Best Bread
Company:
Los Angeles
location
3
Snowflake Flour, one of Best Bread's suppliers, has access to a special extranet site that
acts as a link between the two companies.
Such a site might give its employees access
to information like Best Bread's production
schedules, contact information for purchasing
managers, and purchase order and invoice
information. Because Snowflake's
connection to the extranet moves
across the Internet, it requires technology similar to what Best Bread's Los
Angeles office uses to access the company intranet, and must go through Best
Bread's network firewall.
Extranet Page
Public Internet
Supplier company