Element 1: Computers

Each computer on the network must have an RJ45 Ethernet port. Many, if not most, computers sold today come with this port built in.

If your computer has this port, it's network-ready from a hardware perspective. If it doesn't have an RJ45 port already in place, you'll need to install a network card to provide the port. (See the "Install A Network Card" sidebar.)

Element 2: Central Connecting Device

The network cables from each computer will be routed to the same physical location and connected to a central device that acts as your network's data junction. Depending on your needs, this device can be a hub, a switch, or a router.

Think of a hub as a traffic intersection in a quiet neighborhood. A four-way stop sign will do a fine job of regulating the light traffic. Hubs simply have multiple RJ45 ports to accommodate the connections from the different computers. Hubs are the least expensive option of the three, and for networks that aren't connected to the Internet and won't be subjected to heavy data transfer among the different computers, they work just fine.

Now, imagine a much busier downtown intersection. At the core, the intersection is still just two streets that cross each other, just like the intersection in the quiet neighborhood. But, in order for the traffic to flow smoothly and efficiently, a traffic light is in place to automatically regulate traffic in an orderly and efficient manner. A network switch works in similar fashion, by analyzing the data that passes through and sending it where it needs to go. The result is a smoother, more efficient transfer of data.

Finally, picture a busy downtown intersection beside a freeway. A more sophisticated traffic control system is in place here, one that adjusts itself automatically depending on traffic flow at any given time of day. And most importantly, this traffic control system also allows traffic to access the adjacent freeway via a ramp that connects the freeway to the intersection. For a network connected to the Internet (aka, the information superhighway), a router is the best choice because it intelligently handles traffic between computers, like a switch, and also manages the network's connection to the Internet, automatically.

Element 3: Wiring

Staying with our motor traffic analogy a bit longer, if hubs, routers, and switches serve as intersections, the network wires that connect the computers to those devices are our electronic streets and roadways.

An Ethernet cable consists of a sheathed collection of four pairs of wires, with identical RJ45 connectors on each end. RJ45 connectors resemble telephone connectors but are larger. These wires are color coded for convenience, with the two wires that make up each pair twisted together. You have three choices today when purchasing cable for your network: Category 5, commonly referred to as Cat 5; Category 5 Enhanced, or Cat 5e; and Category 6, aka Cat 6. All three cables are configured the same, with four twisted pairs. The difference is that the higher grades of cable are manufactured according to stricter standards. Certain types of Ethernet networks, which we will discuss below in more depth, require different grades of cable. To be on the safe side, and to prepare for the future when you might want to bump your network up to a new level, use at least Cat 5e cable in your new network.

And just as you don't want to drive on streets filled with potholes, you don't want your network experience to be impeded by wiring glitches, so use quality cabling. See the "Make An Ethernet Cable" sidebar for more information on cable.

Dig Deeper: One Standard, Multiple Flavors

Within the Ethernet camp, different performance levels are available. Expressed in Mbps (megabits per second), the choices are 10, 100, and 1000, the latter commonly called a gigabit network. Practically, the choice is simpler: 10/100 or 10/100/1000, with the former being far more common and considerably less expensive.

10/100 gear can run at either 10Mbps or 100Mbps. For example, a 10/100 router (or hub, or switch) will accept connections from network cards running at either 10Mbps or 100Mbps. Auto-sensing circuitry within the device detects the data rate and makes the appropriate internal adjustments. Likewise, a 10/100 card is compatible with network cards running at either speed in other computers, as well as hubs/switches/routers running at either speed. If all gear is 10/100, the network will run at the faster 100Mbps rate. And because virtually all contemporary gear is at least 10/100, the only reason you should encounter the slower 10Mbps rate is if you're using old gear somewhere on the network. It's important to note that a piece of gear that has only one speed listed, 10 or 100, will operate only at that speed. A straight 10Mbps network card, for example, will not work properly with a straight 100Mbps hub.

Although 10/100 is more than fast enough for most applications, if you're planning to move large amounts of data across your network, you might want to consider a gigabit-capable setup. (You'll see a noticeable difference in transfer speeds between the two, for example, if you're copying hundreds of megabytes of data across the network.) Gigabit gear is only now becoming widely available in the consumer market, and it currently costs significantly more than 10/100 equipment. Remember, to take advantage of the increased speed potential of gigabit-level transfers, you must have gigabit-capable gear at every point in the network connection. If you have a gigabit-capable (10/100/1000) network card in one computer and want to copy data to another computer on the network using the gigabit speed, you must have a gigabit-capable hub/switch/router, as well as a gigabit-capable network card in the destination machine. The transfer can only occur at the highest speed the different pieces of gear have in common. Thus, if you mix 10/100 equipment with 10/100/1000, the resulting speed will be 100Mbps.

Should you decide to go with gigabit equipment, also pay careful attention to the specifications before you buy. Gigabit switches and gigabit routers may have only one or two ports that are actually gigabit-capable, while the majority of their ports are 10/100.

Put It All Together

With the choices made and gear bought, it's time to make your network real. For the sake of writing-and-reading efficiency, we will use "router" to refer to the central connecting device, even though you may have chosen a hub or switch for your network. Let's roll.

1. Run the wiring. If all of your computers, along with the router, are close to each other, you have the option of using premade cabling. If this is the case, wiring the network is as simple as running a premade data cable from each computer's location to the router's location. It's always a good idea to leave a little extra length on each end, so you can move the gear around a bit without disconnecting everything. Just run the cables; don't connect them yet.

If distance or other factors compel you to assemble your own cables, the task may be more challenging. At a minimum, you'll need enough bulk cable, plenty of RJ45 connectors, and a crimping tool made specifically for the task.

Depending on the construction and furnishings of your home or office, the difficulty level of physically running the wire can vary from ultra-easy to nightmare. The job may call for few tools, or it may require an assortment of specialty tools that are hard to find and expensive to buy or rent. Only you can decide whether you're up for such a job, but before you start drilling in walls and floors, be absolutely certain you know what you're doing! Drilling into a wall or floor could mean drilling into electrical wiring or water lines or even gas pipes, actions that could be harmful to you and/or your home or office, or even fatal to you and yours. If you're not experienced and comfortable with this level of work, call a professional who is. Types of contractors who often run wiring include not only network installation professionals, but also burglar alarm installers and custom audio/video installers.

Once the cabling is in place, you'll need to attach RJ45 connectors on both ends of each cable run. And because you'll have multiple cables coming into the router location, be sure to label each one as it is run, so you'll know which computer it connects to on the other end. Don't connect the cables to the router or computers yet.

2. Make the computers network-ready. If your computer has an Ethernet port built in, you'll need to check to see if it's enabled. Click Start and then Control Panel. (Be sure your Control Panel is set to Classic View. If not, click Switch To Classic View in the upper-left pane of the Control Panel window.) Double-click Network Connections. If the Ethernet port is enabled, you should see an icon that says Local Area Connection. If you don't see the icon, the Ethernet port is probably disabled in your computer's BIOS (Basic Input/Output System) settings.

Restart the computer and enter the BIOS setup. (You can usually enter the BIOS setup by pressing either DELETE or F2; watch the screen for instructions immediately after power-up. If you don't see them, consult your motherboard's manual.) Look through the menus until you find the setting for Onboard LAN, Onboard Network, or Onboard Ethernet and change the setting to Enabled. Save the BIOS settings and restart the computer. Your Network Connections window should now contain the Local Area Connection icon.

If your PC doesn't have an Ethernet port, you'll need to install a network card. (Once again, see the "Install A Network Card" sidebar for more information.) Once you've installed the card and it's ready to use, you should see the Local Area Connection icon in the Network Connections window.

If necessary, repeat the appropriate steps we've mentioned to make sure the computers you intend to link to your network are network-ready.

3. Connect. This part is easy. Yeah, we know you've heard that before, but this time it's true. Turn everything off. Connect the network cable to the network port on each computer. Connect the other ends of those cables to the ports on the router. Do not plug these cables into ports labeled Uplink, Internet, WAN, or Broadband Modem.

If you're using a router and connecting the network to a broadband Internet connection, connect a standard Ethernet cable from the modem's Ethernet port (most routers only have one such port) to the appropriate port on the router. It may be labeled Internet, WAN, or Broadband Modem.

That's it! You're network should be ready to go.

4. Configure. Write down any usernames and passwords you need for your Internet connection. If your network has a router, look in the manual to determine its configuration address, username, and password and write down that information, as well.

If present, make the broadband modem first. Now power up the router, and finally, turn on all the individual computers. With everything up and running, choose an individual computer to configure first. If your network doesn't have a router and you plan to share an Internet connection, you'll want to configure the ICS (Internet Connection Sharing) host computer first. The ICS host is the computer that will connect to the Internet and share that Internet connection with other computers on the network.

Click Start, My Computer, and then My Network Places. Give the My Network Places windows a minute or two to scan the network for other computers. If you see other computers in the window, double-click one of them. If that computer "opens," chances are you've configured everything properly. WinXP is quite proficient at automatically configuring networks, and it's often just this simple. If this is the case, and you're setting up a broadband Internet connection with a router, skip the next paragraph.

If you don't see other computers in the My Network Places window, or if this computer will be an ICS host, click Set Up A Home Or Small Office Network in the upper-left pane of the My Network Places window to launch the Network Setup Wizard. Click Next twice. If the wizard finds any disconnected network hardware, the next screen will alert you. If the listed items are relevant, correct the connection issue and move forward. If the listed items are not relevant, click Ignore Disconnected Network Hardware and continue. The next screen in the wizard offers self-explanatory choices about this computer and your network. Make the appropriate choice and follow the wizard's instructions to completion.

With the first computer "seeing" the network, if you're using a router to manage a broadband Internet connection, it's time to configure the router. Run IE (Internet Explorer), type the router's configuration address into IE's address field, and press ENTER. (http://192.168.1.1 and http://192.168.2.1 are common configuration addresses, but be sure to use the URL that's specified in the router's documentation.) IE will load a special configuration Web page that resides inside the router. Use the documentation from your ISP to enter the appropriate settings for your Internet connection into this configuration page. Cable modems are often preconfigured by the ISP to automatically provide a live Internet connection on its Ethernet port so you don't need to enter a username and password in the router configuration. By contrast, DSL (Digital Subscriber Line) modems often do require you to specify both username and password in router setup. The key is to match the router's settings to the type of Internet connection you have. Unfortunately, not all ISPs provide clear instructions on how to interface their equipment with routers they didn't provide. If this is the case, call the ISP's technical support department for help.

Once the first computer and the Internet connection are operating properly, move to the next computer. Run Internet Explorer and see if you can access the Internet. If so, this computer is on the network. If not, click Start, My Computer, and My Network Places. In the upper-left pane, click Set Up A Home Or Small Office Network in the upper-left pane of the My Network Places window to launch the Network Setup Wizard. Click Next twice. If the wizard finds any disconnected network hardware, the next screen will alert you. If the listed items are relevant, correct the connection issue and move forward. If the listed items are not relevant, click Ignore Disconnected Network Hardware and move forward. The next screen in the wizard offers self-explanatory choices about this computer and your network. Make the appropriate choice and follow the wizard's instructions to completion.

Repeat the steps in the preceding paragraph for each computer on the network. Once all the computers can see the other computers on the network, the network is ready to use.

Enjoy!

You're now ready for a new world of convenience and efficiency. To get the most from your new network, you'll need to decide which resources you want to share on the network. It's pretty common to share data folders, hard drives, and printers. To share a printer, click Start, Control Panel, and Printers And Faxes. Click the local printer you want to share, right-click its icon, and then click Sharing. Click the Share This Printer option, enter a network name for the printer, and click OK. Now go to a remote computer, click Start, Control Panel, Printers And Faxes, and then click Add A Printer in the upper-left pane to launch the Add Printer Wizard. Click Next and select A Network Printer, Or A Printer Attached To Another Computer. Click Next, choose Browse For A Printer, and click Next again. The next screen contains a list of printers available on the network. Select the appropriate printer and click Next. Windows will automatically copy the required printer drivers from the remote machine where the printer is attached to the local machine and finish installing the printer. Answer Yes or No to the default printer question on the next screen, click Next one more time, and then click Finish. Now you can print to that printer, whether it's across the room or down the hall.

The process to share other resources, such as hard drives and folders, is similar: From Explorer on the local machine that contains the item to be shared, right-click the icon for the item you want to share and click Sharing or Sharing And Security, and enter the appropriate settings.

To use shared resources such as these on a remote machine, go to My Network Places, either directly from the Start menu or via Explorer, locate the item, and double-click to open it just as you would a local drive or folder.

Do be security-minded as you set up shared resources. Be very careful about sharing folders or drives that contain sensitive or critical data. If you must share such data on the network, set password controls.

by Jerry Hatchett

Make An Ethernet Cable What grade of cable? We recommend at least Cat 5e (Category 5 Enhanced), which will work for both 10/100 and gigabit-level networks. If you plan to expand or create faster networks in the future, consider Cat 6 (Category 6). Buy quality cable and quality RJ45 connectors. What tools? Use wire cutters and a RJ45 crimp-tool that is compatible with the RJ45 connectors you're using. Carefully strip away enough of the outer sheath so you can access approximately one-half inch of the four wire pairs. (The exact amount to be stripped will vary according to brand and style of RJ45 connector.) Inspect the eight internal wires to verify that they weren't nicked or crimped when you stripped the outer sheath. If you find any damage, retrim the entire cable and start over. Separate the eight wires into four flat pairs, as shown below. For technical reasons, it is not sufficient to use any random order, and, of course, use the same order on both ends of the cable. Be safe: Use the color code shown below on both ends. Carefully maintaining the color sequence, insert the eight wires into the grooved receptacle of the RF45 connector and firmly crimp.

Install A Network Card Color codes are very important when assembling your own Ethernet cables. First things first: Some network cards require the accompanying software to be installed first, while others mandate installation of the hardware first. Correcting an error of doing these steps in the wrong order can be extremely difficult, so do read the instructions! Hardware Installation Tips Disconnect the AC power cord from the back of the computer. Wear an antistatic wrist strap if possible. If you don't have one, touch and hold the metal chassis of the computer for a moment to discharge any build-up of static electricity. Using a nonmagnetic screwdriver, remove the computer cover. Carefully stow the screws and make sure you don't let them or any other foreign objects fall into the computer and remain there. Find an empty expansion slot and remove its access cover plate. Insert the network card's connector edge into the expansion slot, push straight down firmly enough to thoroughly seat the card, and secure it with a screw. Replace the computer cover and reconnect the power cord.