Monday, January 1, 2007

Intranet surfing

We've all heard plenty about how computers worldwide can communicate via the Internet. But another trend that is equally important is developing and has as yet received less attention: intranets. Intranets are internal, or office, networks. In other words, a set of computers within a business or work group are connected so they can communicate with one another. An intranet uses the same protocols and languages as the larger Internet, only within a smaller, local network. (However, if the intranet server is attached to the Internet, everyone in the intranet has access to the Internet--but more on that later.)

Each computer within an intranet is given a specific address. Communication between computers in the intranet requires use of that address, so outside computers cannot access an intranet unless they have authorization. Therefore, intranets are much more secure than the worldwide Internet, which any computer anywhere can access. Intranets are becoming increasingly common in businesses, schools, medical clinics, and other settings in which a small, fast, cheap network is needed.

How does an intranet work?

The basic operation of an intranet is much like that of the Internet, only on a much smaller scale. A standard communication protocol (called Transmission Control Protocol/Internet Protocol) enables communication between computers. Each computer is allowed to send information in "packets" to any other computer with an approved intranet address. Each computer on the network has a unique Internet Protocol address, which is a four-segment set of numbers separated by periods (eg, A destination address is attached to each packet of information by the sender, and the packet goes only to the computer with the correct address.

A welcome benefit of intranets is that a network of relatively low-cost computers, even computers of different models and types (eg, mainframe and personal computers, Macs and IBMs), can be used. Rather than needing high-cost proprietary software, intranets run on the familiar Web browsers used for Internet surfing (eg, Netscape, Microsoft Explorer). Since Web-browsing software is available for many computer platforms, the problem of how to get different types of computers to communicate on a single network is eliminated.

Like Web pages, intranet pages often have links to other pages, but these links are to information packets contained in the internal network.

What is needed to set up an intranet?

This is where the process gets a little tricky. As with most endeavors, there is an easy way and a complicated way to go about it.

First, the easy way: Both Microsoft (Personal Web Server version 4.0) and Apple (Web Sharing in Mac OS 8) offer free software allowing a computer that is connected to the Internet (or an intranet) to be a server for sending and receiving information (ie, a Web server). An office or clinic setting up an intranet can have one computer with a permanent connection to the Internet (via a modem or direct connection through a local area network). Then, other computers can connect (again, by modem or direct connection) to the computer designated as the server to send or receive information to others in the intranet. With use of an Internet connection, the difficulties of address assignment and security are minimized, since those issues are handled by the Internet Service Provider that is responsible for the Internet connections.

Now, the more complicated way: This method offers a more complete intranet with enhanced security that prohibits any outside computer hacker from gaining access. One computer in the network is set up with some basic control software to work as the dedicated server for the network. The server handles and monitors traffic, security, and other network requirements, and it acts as the central storage area to hold information until it is needed by another computer. When a request comes in, the server moves the information from storage to the computer making the request. Software is available that assigns a specific address to each computer on the network and that prohibits access to network resources except for computers with the assigned addresses. Intranet systems such as this are a complete internal network built around the in-house server.

How are changes made to intranet systems?

The people who attend to Web pages and central computers are called Webmasters. With networks, the worldwide Web, and Web browsing becoming essential to the operation of almost all businesses, the skills of Webmasters are highly valued. So if you're in the market for a new network, or if you'd like to have a Web site for your clinic or hospital, think about finding a Webmaster. Someone has to take care of changes, copyright issues, and other odds and ends related to maintaining existing pages. And as soon as you include a user-feedback link, you'll get requests that material and information be added. (Take a peek at the Postgraduate Medicine site at, and remember that someone has to add the index, symposium articles, and columns each month and handle reader registrations and queries.)

Don't be afraid to consider becoming a Webmaster yourself. It's a good way to find out what others in the organization are thinking and find valuable. It's also a good way to get involved, use your creativity, and possibly even have fun!