All Categories :
Intranets
Chapter 1
A Global View of Intranets
CONTENTS
What exactly is an intranet? It's one of those terms that's more
thrown around than understood, and has become more of a buzzword
than a commonly understood idea. Simply put, an intranet is a
private network with Internet technology used as the underlying
architecture. An intranet is built using the Internet's TCP/IP
protocols for communications. TCP/IP protocols can be run on many
hardware platforms and cabling schemes. The underlying hardware
is not what makes an intranet-it's the software protocols that
matter.
Intranets can co-exist with other local area networking technology.
In many companies, existing "legacy systems" including
mainframes, Novell networks, minicomputers, and various databases,
are being integrated into an intranet. A wide variety of tools
allow this to happen. Common Gateway Interface (CGI) scripting
is often used to access legacy databases from an intranet. The
Java programming language can be used to access legacy databases
as well.
With the enormous growth of the Internet, an increasing number
of people in corporations use the Internet for communicating with
the outside world, for gathering information, and for doing business.
It didn't take long for people to recognize that the components
that worked so well on the Internet could be equally valuable
internally and that is why intranets are becoming so popular.
Some corporations do not have TCP/IP networks, the protocol required
to access the resources of the Internet. Creating an intranet
in which all the information and resources can be used seamlessly
has many benefits. TCP/IP-based networks make it easy for people
to access the network remotely, such as from home or while traveling.
Dialing into an intranet in this way is much like connecting to
the Internet, except that you're connecting to a private network
instead of to a public Internet provider. Interoperability between
networks is another substantial bonus.
Security systems separate an intranet from the Internet. A company's
intranet is protected by firewalls-hardware and software combinations
that allow only certain people to access the intranet for specific
purposes.
Intranets can be used for anything that existing networks are
used for-and more. The ease of publishing information on the World
Wide Web has made them popular places for posting corporate information
such as company news or company procedures. Corporate databases
with easy-to-build front-ends use the Web and programming languages
such as Java.
Intranets allow people to work together more easily and more effectively.
Software known as groupware is another important part of intranets.
It allows people to collaborate on projects; to share information;
to do videoconferencing; and to establish secure procedures for
production work. Free server and client software and the multitude
of services, like newsgroups, stimulated the Internet's growth.
The consequence of that growth stimulated and fueled the growth
of intranets. The ease with which information can be shared, and
with which people can communicate with one another will continue
to drive the building of intranets.
An intranet is a private corporate or educational network that
uses the Internet's TCP/IP protocols for its underlying transport.
The protocols can run on a variety of network hardware, and can
also co-exist with other network protocols, such as IPX. People
from inside an intranet can get at the larger Internet resources,
but those on the Internet cannot get into the intranet, which
allows only restricted access from the Internet.
- Videoconferencing is an important application that requires
sending massive quantities of data. Intranets can be built using
components that allow the extremely high bandwidths required for
transferring such information.
- Often an intranet is composed of a number of different networks
inside a corporation that all communicate with one another via
TCP/IP. These separate networks are often referred to as subnets.
- Software that allows people to communicate with each other
via e-mail and public message boards and to collaborate on work
using workgroup software is among the most powerful intranet programs.
Applications that allow different corporate departments to post
information, and for people to fill out corporate forms, such
as time sheets, and for tapping into corporate financial information
are very popular.
- Much of the software used on intranets is standard, off-the-shelf
Internet software such as the Netscape Navigator and the Microsoft
Explorer Web browsers. And customized programs are often built,
using the Java programming language and CGI scripting.
- Intranets can also be used to allow companies to do business-to-business
transactions, such as ordering parts, sending invoices, and making
payments. For extra security, these intranet-to-intranet transactions
need never go out over the public Internet, but can travel over
private leased lines instead.
- Intranets are a powerful system for allowing a company to
do business online, for example, to allow anyone on the Internet
to order products. When someone orders a product on the Internet,
information is sent in a secure manner from the public Internet
to the company's intranet, where the order is processed and completed.
- In order to protect sensitive corporate information, and to
ensure that hackers don't damage computer systems and data, security
barriers called firewalls protect an intranet from the Internet.
Firewall technology uses a combination of routers, servers and
other hardware and software to allow people on an intranet to
use Internet resources, but blocks outsiders from getting into
the intranet.
- Many intranets have to connect to "legacy systems"-hardware
and databases that were built before an intranet was constructed.
Legacy systems often use older technology not based on the intranet's
TPC/IP protocols. There are a variety of ways in which intranets
can tie to legacy systems. A common way is to use CGI scripts
to access the database information and pour that data into HTML
formatted text, making it available to a Web browser.
- Information sent across an intranet is sent to the proper
destination by routers, which examine each TCP/IP packet for the
IP address and determine the packet's destination. It then sends
the packet to the next router closest to the destination. If the
packet is to be delivered to an address on the same subnetwork
of the intranet it was sent from, the packet may be able to be
delivered directly without having to go through any other routers.
If it is to be sent to another subnetwork on the intranet, it
will be sent to another internal router address. If the packet
is to be sent to a destination outside the intranet-in other words,
to an Internet destination-the packet is sent to a router that
connects to the Internet.
Contact
reference@developer.com with questions or comments.
Copyright 1998
EarthWeb Inc., All rights reserved.
PLEASE READ THE ACCEPTABLE USAGE STATEMENT.
Copyright 1998 Macmillan Computer Publishing. All rights reserved.
SHOPPING
JOB BANK
REFERENCE
JOURNAL
COMMUNITY
ABOUT US