4. Intranet

The previous pages describe the Internet and some of the services it makes possible. But the Internet is an open network. Which means anyone can connect to it.

Characteristics

What companies also wanted was a private system that allows virtually all the same services but only their own authorised employees can access it.

This is called an 'Intranet'.

The characteristics of an Intranet are almost the same as the Internet. It uses the TCP/IP protocol to allow internal computers to communicate with one another.

The Intranet runs over a Local Area Network (LAN). For larger organisations it may run on a Wide Area Network (WAN). Should the LAN or WAN also be supporting other services, then the Intranet may be a 'virtual network' within the LAN / WAN infrastructure.

On top of the Internet technology there will be an username-password system in place to authorise access.

Purpose:

Virtually the same as the Internet, but for internal use only. Services include

• Email
• File transfer
• Real time chat including video
• World Wide Web
• Video and Audio streaming services

Each service requires at least one server to provide the service e.g. Web server and Email servers.

Although it is unlikely that the video and audio services are there for entertainment (unlike the Internet). They can be used to stream business multimedia - for instance the marketing departments' latest advertising work or dedicated video training packages streamed to the employee's computer.

Advantage of an Intranet.

In theory every employee could use the Internet to get the same services. But an Intranet has the following advantages

• Commercial data is kept secure
• Emails remain private and may also be encrypted
• High bandwidth. No connection limits unlike the Internet
• Reliable. The company will have dedicated IT personnel to keep things running smoothly. No one owns the Internet so there is no 'Quality of Service' guarantee.