Do-it-yourself tips for creating a PC network

By Kim Komando

If you've got more than two computers in your office, they should be connected by a network. That, to me, is a no-brainer.

Here's the good news. Now more than ever, networks to share printers, scanners, files, and Internet access are relatively easy to set up. And the equipment is not expensive.

You'll need to do some homework before buying and setting up the gear. Not much, I promise. Read on.

Your P's (peers) and C's (clients)

Your first assignment: Think about your environment and needs. If security is not crucial, your job is made a lot simpler. You can use what's called a "peer-to-peer" network. It's the easiest type of network to set up.

You simply hook all the computers together. Everyone can have access to everyone else's hard drive and files. This isn't to say you can't limit a person's ability to view or modify a file. You can. A peer-to-peer network is just not as encompassing as the other type of network: "client/server."

With a client/server network, you have an extra computer that does nothing else but "serve" the people (or the "clients") in the office. This computer contains files that everyone needs — such as your customer database and sales propaganda. It's a more expensive and complicated way to go, but is much more secure.

There's also another big advantage to a client/server network — data backups. You don't have to worry if Sandy in Accounting has a recent copy of your financial records should her computer go to the great intergalactic bit bucket. Most backup software allows for unattended and automatic backups. Use this software to run daily or weekly backups of the data on your network's server.

You can network Windows or Macintosh machines. In fact, you can mix them on the same network.

Ethernet: old and reliable

The oldest, fastest and most reliable networking system is Ethernet. This is a hard-wired system, with physical cables (called "CAT-5") running between machines.

Each computer will need a network interface card, also known as a network card or NIC. Your computers may already have them. Check the backs of your computers for a single port. It will look like a telephone connection, but will be about 50% larger. If you need NICs, they'll cost $15 or less each.

All of the computers have to be cabled into a hub. The peripherals also are connected to the hub. That way, everybody has access to everything.

If you're planning to share your Internet access with the computers on the network, you'll also need a router. Inexpensive hub/router combinations are available. But don't forget security. You'll need some type of firewall — otherwise intruders could enter your system from the Internet.

There are two types of firewalls: hardware and software. Routers often have firewalls built in. They're worth the investment. Or you could use one of your computers as a router, running the hub through it. This is cheaper, but the harder way to do things. But if you go this route, you should protect your system with a software firewall. But whatever you decide, don't forget to protect your network.

When shopping, you'll find that Ethernet has two standards: 10 and 100 megabits per second (mbps). Ten mbps is reasonably fast; 100 kicks butt. For example, if you move a 50-megabyte file over a 10-mbps network from one computer to another, it'd take about 40 seconds. At 100 mbps, it'd take about four seconds. If you're moving a lot of huge files, the higher rate would be important to you. Otherwise, the lower rate should suffice. The 100-mbps system will cost you little more.

Cabled systems are well understood and thoroughly developed. You'll find expansion is easy as your business grows. And they're pretty cheap. You should be able to network a five-computer system for less than $300. This includes the hub/router, cables and network cards for the individual computers.

Some newer office buildings (and houses) have Ethernet cabling built into the walls. If that is your case, great! Hooking up your computers is like installing telephones. But if the cabling is not built in, you'll have to cable yourself. That could be an aesthetic issue; not everyone appreciates the industrial beauty of cables.

Elegant but slow systems

Those who like a little form with their function might find other types of networking more appealing. But while you gain in aesthetics, you'll lose speed. The newer systems just can't stay up with cables.

Two of them, PowerPacket and HomePNA, are intended for home networks. But they could also work for a small business. Both are relatively recent developments. They are simpler to set up than a cabled system.

HomePNA (www.homepna.org) runs the network through the phone system. This will work just dandy, so long as your outlets are well-placed.

In effect, the telephone lines in the walls become your cables. Each computer plugs into a telephone outlet, as does the hub/router. The software automatically recognizes each component of the system.

Telephone calls run on a different frequency, so they do not clash with the computer network. If you have DSL, it runs on a third frequency. So there's no problem with it, either.

HomePNA runs at 10 mbps, which is probably fast enough for a very small business network. Figure $500 to $600 for a five-computer system.

PowerPacket (www.intellon.com) is routed through your electrical lines. It is even more convenient than HomePNA, because power outlets are everywhere. It runs at 14 mbps. As with HomePNA, the software automatically finds the network's components. There's a lot of potential interference on electrical lines, so PowerPacket routes the signal over different frequencies. If it hits a problem, it changes channels.

Look Ma, no wires!

The final system is wireless, an area growing like wild mushrooms. Individual computers are connected to a base station within a small area. Wireless can reach 1,000 feet in a relatively open environment; figure 250 to 400 feet in an enclosed area with walls. Concrete and metal walls can block or severely hamper the wireless signal.

These systems communicate by wireless signal. Computers can be moved, so long as they stay within the communication area.

If you're planning the deployment of a wireless network, you now face a choice between three standards: 802.11a, 802.11b or 802.11g. Most installations are still using 802.11b equipment, which transmits data at 11 mbps, the slowest speed of the three. 802.11a is significantly faster, running at 54 mbps and is appropriate for high performance users who need to support transmission of video, voice and large image files. But its range is limited. 802.11g combines the best of both -- and has shown to be the most secure -- but may also be the most expensive.

Wireless systems do have security issues, particularly 802.11a and 802.11b. They put your signal into the air, where it could be picked up by anyone nearby. Therefore, the data has to be encrypted. Wireless encryption for these two standards is based on the Wired Equivalent Privacy (WEP) algorithm, which some have called a hacker's delight. The 802.11g standard specifies a newer security mechanism called Wi-Fi Protected Access (WPA), an improvement on WEP, most agree.

If you install a wireless system, pay special attention to the maker's security instructions. Be very careful to install passwords or algorithm keys where required. Do not use your dog's name, any word that can be found in the dictionary, or numbers such as 111111 or 123456. Intruders use software that will quickly find these combinations.

Although networking is not rocket science, you may still want the help of a professional. Windows XP has made networking much easier, but a neophyte could still have problems. As I'm sure you well know, computers aren't as simple as they should be.