Building the 85 Network

Installing a Small Wi-Fi Network: Overview

The following points provide an overview of the process I've found that works best for small networks. But before you study those points, here is an important metapoint that you shold consider:

Read this whole chapter to the end before you do anything!

Really!

Here's your general modus operandi:

1. Begin by installing your router appliance or wireless gateway, which should be installed near where your broadband Internet connection is. If any of your computers have Wi-Fi client adapters already installed, turn those computers off while you install the router appliance, gateway, and/or access points.

2. At least one computer must be connected, at least temporarily, to your router or gateway via category 5 Ethernet cable. Configuring a wireless link over the wireless link is just nuts. (This doesn't keep people from trying it.) This computer should not have a wireless client adapter installed yet.

3. Before changing anything on your router or computers, write down the existing settings that you're changing. Here's one place where paper trumps silicon every time: Keep your 'changes log' on a paper notepad, in pencil.

4. If you already have a router-based network, make sure it's working correctly before attempting to add wireless functionality. DHCP must be enabled and operating.

5. Do your cabling with the power off to everything. Plugging and unplugging Ethernet cables with the power on may not physically damage anything, but the devices may get bollixed and post confusing messages on your screen.

6. If you're installing a network with two access points (or more), install one first and then audit the microwave field before installing the others. (I'll explain how to do this later.) It's impossible to tell ahead of time how well an access point will 'fill' a structure, what its range is, or where your dead spots will be. Your advance design is only an educated guess. Where you mount the second or subsequent access points may depend on how well the first ones cover the required area. And, of course, there's always the chance that a single access point will do the job throughout the coverage area and you won't have to install the others. Still, you may wish to do so for 'load balancing' if you have more than five or six client computers connecting wirelessly within the coverage area.

7. Once the access point or gateway has been cabled and powered up, use the computer connected to it via CAT5 cable to configure the access point or gateway. Record what you enter, and the defaults (if any) that you change by doing so. After configuration, test the network to be sure that Internet access works. If more than one computer or device is connected via CAT5 cables to the router appliance, gateway, or other switch or hub, test the wired portion of the network to be sure it's operable before installing any Wi-Fi client adapters.

8. Once you have the wired portion of the network installed, configured, and tested, install the first client adapter in one of your other computers. Perform the installation following the instructions provided by the manufacturer for that client adapter, but in general, you should install the drivers and utilities before plugging in the adapter itself. If you plug the adapter in first, Windows Plug and Play may install an older set of drivers automatically. If you have a laptop, install the laptop client adapter first. This will allow you to audit the field by walking around with the laptop, to be sure the field is sufficiently strong in those locations where other Wi-Fi-connected computers will be based.

9. If your audit of the field looks good, install the other client adapters in your other computers one at a time, bringing each one up and testing it before going on to the next. If you're using 802.11b Wi-Fi, make sure each client computer connects at the top bit rate of 11 Mbps (22 MBps for 802.11b+). If you're using 802.11a, you probably won't connect at the top rate of 54 Mbps everywhere, but you should be able to connect at 18 Mbps or more. If one of your client computers ends up in a weak spot or a dead spot, you may have to add an external antenna (see Chapters 8 and 15) or use a movable client adapter, like a USB adapter.

10. When all client adapters have been installed and their links tested, read Part 3 of this book (Chapters 11 through 14) and then enable Wired Equivalent Privacy (WEP) security for your network. Do not skip this step!

11. (Optional) If you're ambitious, install the free throughput tester utility QCheck and test your data throughput across all your wireless links. (I explain how to do this later.) Record the results.

At this point, if nothing goes wrong, you're done, and you have a network. Be sure to keep your written notes and change logs in a binder of some kind, along with the rest of your computer configuration notes. Such notes are invaluable later when things act up, when you upgrade your network gear, or (most of all) when you buy an entirely new computer and want to add it to your network, in addition to or as a replacement for one of your existing computers.

What You'll Need from Your Internet Service Provider

If you're installing a wireless network, you probably already have a broadband Internet connection. When you obtained your broadband connection, your Internet service provider (ISP) gave you several configuration values. These may be listed in a booklet or on a sheet of paper. If not, they are probably accessible from the Windows Control Panel.

The key question is whether your ISP gave you static address information, or requires you to use their remote DHCP server to bring down dynamic address and mask information. The DHCP option makes things much easier. Getting a static IP address is pretty rare these days, and if your Internet connection is fairly new it's extremely unlikely.

However, if you do have static address information, the items you'll need are these. All are 'dotted' sequences of four octets, as explained in Chapter 3:

• A primary IP address (something like 264.148.8.221)

• A subnet mask (something like 255.255.255.0 or 255.255.0.0)

• A default gateway address, which is an IP address like but not identical to the primary address

• At least one but more likely two DNS server addresses, which are IP addresses like but not identical to the primary address

If you have a DSL broadband connection, you may have a login username and password as well. This depends entirely on your ISP.

If you can't find the configuration information that you were given by your ISP, you can find it by looking in the right places in the computer directly connected to your cable/DSL modem. I'll explain how to do this in Appendix C.

Small Things Count!

There are a number of very small hints and disciplines that make computer systems and networks easier to maintain over time. Let me run through them before we move on and begin construction.

1. Keep a log on paper, not simply of your network installation but of any major configuration change you make to any of your computers and major peripherals. It may sound atavistic, but I keep a paper-based log of my computer and network configuration, changes, release levels, installed software, and so on. I keep it on paper so that even if all of my machines are down and unworkable, I can bring in a new one and start again from scratch.

2. Buy a selection of short CAT5 patch cables in different colors. Get as many colors as you can (I have five) in 3' or 5' lengths. I order them from Data Comm Warehouse ( www.warehouse.com) but they are available in many places. The idea is not to use more than one patch cable of a given color in the cable rats' nest around your router and access point. Record it in your log: The red cable goes from the router to your access point. The green cable goes from your main computer to your router, and so on. Cables tend to vanish into a shapeless mess of wiring behind your desk, and it helps to find the 'other end' if they're not all gray!

3. If you're using network appliances that 'stack' (the Linksys line is the best example-see Figure 9.1) put the wireless unit (gateway or access point) on top. Putting something on top of the wireless box will interfere with the wireless unit's antennas and distort the shape of your microwave field. This may reduce the range of your unit or cause weak or dead spots.

   
   Figure 9.1: Stacked Network Appliances. (Photo courtesy of Linksys.)

4. Label your wall warts. As you acquire, experiment with, and replace computer gadgetry, sooner or later you will forget which wall-outlet power supply module (which most of us insiders call 'wall warts') goes with which computer gadget. The name of the device is almost never on the wall wart, and in recent years even the manufacturer's name is absent. It's just a generic power supply manufacturer's name, plus the (nearly) ubiquitous legend, 'Made in China.'

Keeping the wart associated with its gadget is critical, because the voltage and polarity of wall warts is by no means always the same. Computer devices and their wall warts are a little like Philip Pullman's fantasy characters and their daemons: They go together, and separating them means big trouble. Plug a wall wart into the wrong gadget and it can fry the gadget, so there's plenty of motivation to keep them sorted out.

I recommend labeling wall warts with the name of the devices that they came with. I use one of those electronic labelers made by Brother and other firms (see Figure 9.2).

Figure 9.2: A Labeled Wall Wart.

My Three Networks

Wi-Fi-equipped networks for homes and small offices tend to fall into three general models:

1. The 85% network. This consists of a wireless residential gateway at the center, plus some number of computers connected via client adapters. The router is part of the gateway appliance, as is the wireless access point. This type of network is very easy to install, and works well for about 85% of people wishing to install an all-new wireless-capable network for a home office or small office.

2. The simple add-on Wi-Fi network. If you already have a wired network with a router appliance in place, you can add a single access point and wireless client adapters without junking your router appliance.

3. The multi-zone Wi-Fi network. Whether you already have a wired network in place or not, if you feel that you'll need more than one access point, it's best to use separate access points to handle your wireless connections, and a wired router/switch appliance to handle routing and wired connections. If you expect to support roaming (see Chapter 6) make sure your access points are of the same manufacturer, model, and firmware release level, with known roaming support. Check before you buy!

These are the networks that I will describe in this chapter. They have a lot in common, and even if you intend to install Network #2 or #3, read the section describing the 85% Network first. I won't repeat everything for all three networks.

There are a lot of refinements that you can add if you want, and sometimes you may find that wireless links just aren't possible from certain places. Basements are notoriously difficult, as are garages, and there are peculiar circumstances that you may encounter, like a king-sized waterbed casting a microwave shadow to floors either above or below it. Kitchens cast shadows (mine certainly does!) due to the presence of big refrigerators and cabinets full of pots, pans, and canned goods.

You just won't know until you try. Nonetheless, these three 'shapes' are the commonest ones, and I'll cover each one separately.