MODEM

TYPE

GATEWAY

USERNAME

PASSWORD

192.168.1.1
192.168.1.1
192.168.1.254
192.168.1.254

blank

blank

192.168.1.1
192.168.1.1
192.168.1.1
192.168.1.1
192.168.2.1

blank

admin

10.0.0.2
10.0.0.2
192.168.1.1
192.168.1.254

admin

epicrouter
password
password
password Acer WlanGRU2

192.168.62.1

admin

password

      To determine the signal strength of your WiFi connection at any given point in time, you can use one or more of the following methods:

• Operating system utility – Microsoft Windows (and other network operating systems) contain a built in utility to monitor wireless network connection status. In the Network Connections section of Control Panel, opening the Status window of the Wireless Network Connection icon reveals a Signal Strength meter. This meter shows up to five green bars representing the current strength on a quality scale from “Very Low” (1 bar) to “Excellent” (5 bars).
• Wireless adapter utility – Some manufacturers of wireless network hardware and/or notebook computers (e.g., Linksys, IBM) provide software applications along with the hardware that also monitor wireless signal strength.
  These applications often report signal strength and quality based on a percentage from 0-100%.
  For example, a connection with an Excellent / 5 bars rating in Windows XP may show in IBM ThinkVantage Access Connections as Excellent with a percentage rating anywhere between 80-100%. These percentages are based on actual radio signal levels maintained by the wireless network adapter, in decibels (dB).
• WiFi locator devices – Resembling a keychain, a WiFi locator device is designed to detect signal strength of nearby wireless access points. Most WiFi locators use a set of between four and six LEDs to indicate signal strength in units of “bars” similar to the Microsoft Windows utility. Unlike the above methods, WiFi locator devices do not measure the strength of your actual connection, they only predict the strength of a connection.

      Note that different tools in the above categories will sometimes report slightly different results. For example, one wireles adapter utility may show a signal strength of “82%” and another “80%” for the same connection, or one WiFi locator may show three bars out of five while another shows four bars out of five. These variations are generally caused by small differences in how the utilities collect samples and the timing they use to average them together to report an overall rating.

Bradley Mitchell

First, wireless local area networks (WLANs) feature differing levels of performance depending on which Wi-Fi standard they support. 802.11b WLANs offer maximum theoretical bandwidth of 11 Mbps. 802.11a and 802.11g WLANs offer theoretical bandwidth up to 54 Mbps. (In contrast, typical wired Ethernets run at 100 Mbps.)

The performance of Wi-Fi networks in practice never approaches the theoretical maximum. 802.11b networks, for example, generally operate no faster than about 50% of theoretical peak, or 5.5 Mbps. Likewise, 802.11a and 802.11g networks generally run no faster than 20 Mbps. The disparity between theoretical and practical performance comes from protocol overhead, signal interference, and decreasing signal distance with distance.

In addition, the more devices communicating on a WLAN simultaneously, the slower the network will appear.
On home networks, keep in mind that the performance of an Internet connection is often the limiting factor in network speed. Even though files can be shared on a wireless LAN at speeds of 5 or 20 Mbps, wireless clients will still connect to the Internet at the speed typically offered by Internet Service Providers, usually less than 1 Mbps.

Finally, wireless network technology is capable of more speed than what Wi-Fi supports today. Industry vendors continue to develop improved technologies like 802.16 WiMAX that offer wireless communications with faster speeds and longer range.

Bradley Mitchell

WLANs
WLANs provide wireless network communication over short distances using radio or infrared signals instead of traditional network cabling.
A WLAN typically extends an existing wired local area network. WLANs are built by attaching a device called the access point (AP) to the edge of the wired network. Clients communicate with the AP using a wireless network adapter similar in function to a traditional Ethernet adapter.

802.11b
802.11b is a WLAN communication standard. 802.11b is one of the wireless Ethernet standards in the 802.11 series. 802.11b LANs support a maximum data rate of 11 Mbps. Although 802.11b performs much better than traditional dial-up networking, the performance of 802.11b is still significantly less than 802.11a and other, newer standards.

Wireless Access Points (APs or WAPs)
are specially configured nodes on wireless local area networks (WLANs). Access points act as a central transmitter and receiver of WLAN radio signals.
Access points used in home or small business networks are generally small, dedicated hardware devices featuring a built-in network adapter, antenna, and radio transmitter. Access points support Wi-Fi wireless communication standards

SSID
An SSID is the name of a wireless local area network (WLAN). All wireless devices on a WLAN must employ the same SSID in order to communicate with each other.
The SSID on wireless clients can be set either manually, by entering the SSID into the client network settings, or automatically, by leaving the SSID unspecified or blank. A network administrator often uses a public SSID, that is set on the access point and broadcast to all wireless devices in range. Some newer wireless access points disable the automatic SSID broadcast feature in an attempt to improve network security.
SSIDs are case sensitive text strings. The SSID is a sequence of alphanumeric characters (letters or numbers). SSIDs have a maximum length of 32 characters.

Wardriving
Wardriving is the practice of searching for wireless LAN (WLAN) signals within a geographic area. Peter Shipley coined this term. He pioneered the practice of using an automobile, a Global Positioning System, and a mounted antenna to identify unsecured WLANs in neighborhoods

WEP Wired Equivalent Privacy
WEP is a protocol that adds security to wireless local area networks (WLANs) based on the 802.11 Wi-Fi standard. WEP is an OSI Data Link layer (Layer 2) security technology that can be turned “on” or “off.” WEP was designed to give wireless networks the equivalent level of privacy protection as a comparable wired network.

To set up MAC address filtering, you as a WLAN administrator must configure a list of clients that will be allowed to join the network.

First, obtain the MAC addresses of each client from its operating system or configuration utility. Then, they enter those addresses into a configuratin screen of the wireless access point or router. Finally, switch on the filtering option.
Once enabled, whenever the wireless access point or router receives a request to join with the WLAN, it compares the MAC address of that client against the administrator’s list. Clients on the list authenticate as normal; clients not on the list are denied any access to the WLAN.

MAC addresses on wireless clients can’t be changed as they are burned into the hardware. However, some wireless clients allow their MAC address to be “impersonated” or “spoofed” in software. It’s certainly possible for a determined hacker to break into your WLAN by configuring their client to spoof one of your MAC addresses. Although MAC address filtering isn’t bulletproof, still it remains a helpful additional layer of defense that improves overall Wi-Fi network security.

Do not confuse MAC address filtering with content filtering. Content filtering on a wireless access point or router allows administrators to maintain a list of Web site URLs or addresses that should not be accessed from the home WLAN

       The 2.4 GHz Wi-Fi signal range is divided into a number of smaller bands or “channels,” similar to television channels.

       In most countries, Wi-Fi equipment provides a set of available channels to choose from. In the United States, for example, any of the Wi-Fi channels 1 – 11 can be chosen when setting up a wireless LAN (WLAN). Setting this WiFi channel number appropriately provides one way to avoid sources of wireless interference.
Many wireless products in the U.S. ship with a default Wi-Fi channel of 6. If encountering interference from other devices within the home, consider changing the channel up or down to avoid it. Note that all Wi-Fi devices on the network must use the same channel.

       Unlike television channels, some Wi-Fi channel numbers overlap with each other. Channel 1 uses the lowest frequency band and each subsequent channel increases the frequency slightly. Therefore, the further apart two channel numbers are, the less the degree of overlap and likelihood of interference. If encountering interference with a neighbor’s WLAN, change to a distant channel. Both channels 1 and 11 do not overlap with the default channel 6; use one of these three channels for best rest.

Bradley Mitchell

• the specific 802.11 protocol employed
• the overall strength of the device transmitter
• the nature of obstructions and interference in the surrounding area

A general rule of thumb in home networking says that 802.11b and 802.11g WAPs and routers support a range of up to 150 feet (46 m) indoors and 300 feet (92 m) outdoors.
Another rule of thumb holds that the effective range of 802.11a is approximately one-third that of 802.11b/g.

Both of these rough estimates fall on the high end of the range seen in practice.

Obstructions in home such as brick walls and metal frames or siding greatly can reduce the range of a Wi-Fi LAN by 25% or more. Because 802.11a employs a higher signalling frequency than 802.11b/g, 802.11a is most susceptible to obstructions. Interference from microwave ovens and other equipment also affects range. 802.11b and 802.11g are both susceptible to these.
Of course, it’s possible to extend a Wi-Fi LAN to much longer distances by chaining together multiple wireless access points or routers.

Bradley Mitchell

Build a Wireless LAN, Step by Step
You can build any typical wireless home network, a wireless LAN (WLAN), using this simple three-step approach: 

• Identify the WLAN design that’s best for your situation
• Choose good wireless gear
• Install gear and test the configured WLAN
  In subsequent pages, I break down each of these steps in more detaills

Benefits of Wireless
Wireless offers tangible benefits over traditional wired networking. Ever tried to quickly look up a recipe on the Net while cooking in the kitchen? Do the kids need a networked computer in their bedroom for school projects? Have you dreamed of sending email, instant messaging, or playing games while relaxing on your outdoor patio? These are just some of the things wireless can do for you:

Next Stop – Terminology
The field of computer networking once sat squarely in the domain of techies. Equipment manufacturers, service providers, and “experts” that study the field of networking tend to go quite heavy on technical jargon. The wireless networking industry is gradually improving on this legacy, making products more consumer-friendly and easier to integrate into the home. But there is still much work for the industry to do. Let’s take a quick look at the common jargon of wireless home networking and what it all means.

Wireless terms and jargon
When researching wireless equipment to buy, or talking about wireless networking with friends and family, you should have a solid understanding of this basic terminology.

What is a WLAN?
We’ve already said that a WLAN is a “typical” wireless home network. That’s because a WLAN is a wireless LAN, and a LAN is a related group of networked computers situated in close physical proximity to each other. LANs can be found in many homes, schools, and businesses. Though it’s technically possible to have more than one LAN in your home, few do this in practice. In this tutorial, we explain how to build a single standard WLAN for your home.

What is Wi-Fi?
Wi-Fi is an industry name used to market wireless networking products. You’ll find a black-and-white Wi-Fi logo or certification emblem on virtually any new wireless equipment you buy.
Technically speaking, Wi-Fi signifies conformance to the 802.11 family of wireless communication standards (described below). But because all mainstream wireless home network gear uses the 802.11 standards today, basically the term “Wi-Fi” merely distinguishes wireless equipment from other network gear.

What is 802.11a/802.11b/802.11g?
802.11a, 802.11b, and 802.11g represent three popular wireless communication standards. Wireless networks can be built using any of the three, but 802.11a is less compatible with the others and tends to be a more expensive option implemented only by larger businesses. Use the supplemental article below to help you pick 802.11 standard(s) for your wireless LAN.
Choosing among 802.11a, 802.11b, and 802.11g wireless

What are WEP and Wardriving?
The security of wireless home and small business networks remains a concern for many. Just like we use radio or television receivers to tune into station broadcasts, it’s almost as easy to pick up signals from a nearby wireless home network. Sure, credit card transactions on the Web may be secure, but imagine your neighbors spying on every email and instant message you send!
A few years ago, some techies popularized the practice of wardriving to raise awareness of this vulnerability in WLANs. With the help of cheap, home-made equipment, “wardrivers” walked or motored through neighborhoods snooping the wireless network traffic emanating from nearby homes. Some wardrivers even logged their computers onto unsuspecting people’s home WLANs, essentially stealing free computer resources and Internet access.

WEP is an important feature of wireless networks designed to improve security. WEP scrambles (technically speaking, encrypts) network traffic mathematically so that other computers can understand it, but humans cannot read it. WEP helps protect your WLAN from wardrivers and nosy neighbors, and today, all popular wireless equipment supports it. Because WEP is a feature that can be turned “on” or “off,” you’ll simply need to ensure it is configured properly when setting up your network.

Next – Types of Wireless Equipment
The five types of equipment found in wireless home networks are:

• wireless network adapters
• wireless access points
• wireless routers
• add-on wireless antennas
• wireless signal boosters

Some of this equipment is optional depending on your home network configuration. Let’s examine each piece in turn.

Choosing wireless gear
The building blocks of a wireless LAN are network adapters, access points, wireless routers, add-on wireless antennas and signal boosters. Of these, only network adapters are truly required to build a wireless home network. However, many wireless LANs also utilize some of the other equipment, as explained below.

Wireless Network Adapters
Each computer you wish to connect to a WLAN must possess a wireless network adapter. Wireless adapters are sometimes also called NICs, short for Network Interface Cards. Wireless adapters for desktop computers are often small PCI cards or sometimes card-like USB adapters.

Wireless adapters for notebook computers resemble a thick credit card. Nowadays, though, an increasing number of wireless adapters are not cards but rather small chips embedded inside notebook or handheld computers.
Wireless network adapters contain a radio transmitter and receiver (transceiver). Wireless transceivers send and receive messages, translating, formatting, and generally organizing the flow of information between the computer and the network. Determining how many wireless network adapters you need to buy is the first critical step in building your home network. Check the technical specifications of your computers if you’re unsure whether they contain built-in wireless adapter chips.

Wireless Access Points
A wireless access point serves as the central WLAN communication station. In fact, they are sometimes called “base stations.” Access points are thin, lightweight boxes with a series of LED lights on the face.
Access points join a wireless LAN to a pre-existing wired Ethernet network. Home networkers typically install an access point when they already own a broadband router and want to add wireless computers to their current setup. You must use either an access point or a wireless router (described below) to implement “hybrid” wired/wireless home networking. Otherwise, you probably don’t need an access point.

Wireless Routers
A wireless router is a wireless access point with several other useful functions added. Like wired broadband routers, wireless routers also support Internet connection sharing and include firewall technology for improved network security. Wireless routers closely resemble access points.

A key benefit of both wireless routers and access points is scalability. Their strong built-in transceivers are designed to spread a wireless signal throughout the home. A home WLAN with a router or access point can better reach corner rooms and backyards, for example, than one without. Likewise, home wireless networks with a router or access point support many more computers than those without one. As we’ll explain in more detail later, if your wireless LAN design includes a router or access point, you must run all network adapters in so-called infrastructure mode; otherwise they must run in ad-hoc mode.
Wireless routers are a good choice for those building their first home network. See the following article for good examples of wireless router products for home networks:

Wireless Antennas
Wireless network adapters, access points, and routers all utilize an antenna to assist in receiving signals on the WLAN. Some wireless antennas, like those on adapters, are internal to the unit. Other antennas, like those on many access points, are externally visible. The normal antennas shipped with wireless products provide sufficient reception in most cases, but you can also usually install an optional, add-on antenna to improve reception. You generally won’t know whether you’ll need this piece of equipment until after you finish your basic network setup.

Wireless Signal Boosters
Some manufacturers of wireless access points and routers also sell a small piece of equipment called a signal booster. Installed together with a wireless access point or router, a signal booster serves to increase the strength of the base station transmitter. It’s possible to use signal boosters and add-on antennas together, to improve both wireless network transmission and reception simultaneously.
Both antennas and signal boosters can be a useful addition to some home networks after the basics are in place. They can bring out-of-range computers back into range of the WLAN, and they can also improve network performance in some cases.

Next – WLAN Configurations
Now that you have a good understanding of the pieces of a wireless LAN, we’re ready to set them up according to your needs. Don’t worry if you haven’t settled on a configuration yet; we will cover all of them.

Installing and Configuring your WLAN
To maximize benefit from the directions below, have your answers ready for the following questions:

• do you want to extend your wired home network with a WLAN, or are you building a completely new network?
• how many wireless computers do you plan to network, and where in the home will be they be located?
• what operating systems do/will you run on your networked computers?
• do you need to share your Internet connection among the wireless computers? how else will you use this WLAN? file sharing? network gaming?

Installing a Wireless Router
One wireless router supports one WLAN. Use a wireless router on your network if:

• you are building your first home network, or
• you want to re-build your home network to be all-wireless, or
• you want to keep your WLAN installation as simple as possible

Try to install your wireless router in a central location within the home.

The way Wi-Fi networking works, computers closer to the router (generally in the same room or in “line of sight”) realize better network speed than computers further away.
Connect the wireless router to a power outlet and optionally to a source of Internet connectivity. All wireless routers support broadband modems, and some support phone line connections to dial-up Internet service. If you need dial-up support, be sure to purchase a router having an RS-232 serial port. Finally, because wireless routers contain a built-in access point, you’re also free to connect a wired router, switch, or hub.

Next, choose your network name. In Wi-Fi networking, the network name is often called the SSID. Your router and all computers on the WLAN must share the same SSID. Although your router shipped with a default name set by the manufacturer, it’s best to change it for security reasons. Consult product documentation to find the network name for your particular wireless router, and follow this general advice for setting your SSID.

Last, follow the router documentation to enable WEP security, turn on firewall features, and set any other recommended parameters.

Installing a Wireless Access Point
One wireless access point supports one WLAN. Use a wireless access point on your home network if:

• you don’t need the extra features a wireless router provides AND
• you are extending an existing wired Ethernet home network, or
• you have (or plan to have) four or more wireless computers scattered throughout the home

Install your access point in a central location, if possible. Connect power and a dial-up Internet connection, if desired. Also cable the access point to your LAN router, switch or hub. See the diagram in the Page 3 sidebar for details.
You won’t have a firewall to configure, of course, but you still must set a network name and enable WEP on your access point at this stage.

Configuring the Wireless Adapters
Configure your adapters after setting up the wireless router or access point (if you have one). Insert the adapters into your computers as explained in your product documentation. Wi-Fi adapters require TCP/IP be installed on the host computer.
Manufacturers each provide configuration utilities for their adapters. On the Windows operating system, for example, adapters generally have their own graphic user interface (GUI) accessible from the Start Menu or taskbar after the hardware is installed. Here’s where you set the network name (SSID) and turn on WEP. You can also set a few other parameters as described in the next section. Remember, all of your wireless adapters must use the same parameter settings for your WLAN to function properly.

Configuring an Ad-Hoc Home WLAN
Every Wi-Fi adapter requires you to choose between infrastructure mode (called “access point” mode in some configuration tools) and ad-hoc (“peer to peer”) mode. When using a wireless access point or router, set every wireless adapter for infrastructure mode. In this mode, wireless adapters automatically detect and set their WLAN channel number to match the access point (router).
Alternatively, set all wireless adapters to use ad hoc mode. When you enable this mode, you’ll see a separate setting for channel number. All adapters on your ad hoc wireless LAN need matching channel numbers.

Ad-hoc home WLAN configurations work fine in homes with only a few computers situated fairly close to each other. You can also use this configuration as a fallback option if your access point or router breaks:

Configuring Software Internet Connection Sharing
As shown in the diagram, you can share an Internet connection across an ad hoc wireless network. To do this, designate one of your computers as the host (effectively a substitute for a router). That computer will keep the modem connection and must obviously be powered on whenever the network is in use. Microsoft Windows offers a feature called Internet Connection Sharing (ICS) that works with ad hoc WLANs.

Troubleshooting, Tips and Tweaks
Now let’s cover some of the finer points you need to know about home wireless LANs.

Wireless Routers / Access Point Interference within the Home
When installing an 802.11b or 802.11g access point or router, beware of signal interference from other home appliances. In particular, do not install the unit within 3-10 feet (about 1-3 m) from a microwave oven. Other common sources of wireless interference are 2.4 GHz cordless phones, baby monitors, garage door openers, and some home automation devices.
If you live in a home with brick or plaster walls, or one with metal framing, you’re may encounter difficulty maintaining a strong WLAN signal. Wi-Fi is designed to support signal range up to 300 feet (about 100 m), but barriers reduce this range substantially. All 802.11 communications (802.11a most of all) are affected by obstructions; keep this in mind when installing your access point.

Wireless Routers / Access Point Interference from Outside
In densely populated areas, it’s not uncommon for wireless signals from one person’s home network to penetrate a neighboring home and interfere with their WLAN.

This happens when both households set conflicting communication channels. Fortunately, when configuring an 802.11b or 802.11g access point or router, you can (except in a few locales) change the channel number employed.
In the United States, for example, you may choose any WLAN channel number between 1 and 11. If you encounter interference from neighbors, you should coordinate channel settings with them. Simply using different channel numbers won’t always solve the problem. However, if both parties use a different one of the channel numbers 1, 6 or 11, that will guarantee elimination of cross-WLAN interference.

MAC Address Filtering
Newer wireless routers and access points support a handy security feature called MAC address filtering. I wholeheartedly recommend it. This feature allows you to register wireless adapters with your access point (or router), and force the unit to reject communications from any wireless device that isn’t on your list. MAC address filtering combined with WEP encryption affords very good security protection

Wireless Adapter Profiles
Many wireless adapters support a feature called profiles that allows you to set up and save multiple WLAN configurations. For example, you can create an ad hoc configuration for your home WLAN and an infrastructure mode configuration for your office, then switch between the two profiles as needed. I recommend setting up profiles on any computers you plan to move between your home network and some other WLAN; the time you spend now will save much more time and aggravation later.
WEP Encryption
Among the options you’ll see for activating wireless encryption, 128-bit WEP is a safe bet. Older 40 or 64-bit WEP offers inadequate protection. A few 802.11g products support 152-bit or 256-bit WEP, that is fine too, if all of your gear supports it. Newer equipment offers WPA. General-purpose WPA is unnecessarily complex for a home WLAN, but WPA-PSK works well.

To set 128-bit WEP, pick and assign a number called a WEP passkey. You must apply the same WEP settings and passkey to the access point (router) and all adapters.

General Tips
If you’ve finished installing the components, but your home network isn’t functioning correctly, troubleshoot methodically:

• Can’t reach the Internet? Temporarily turn off your firewall to determine whether you have a firewall configuration problem, or some other issue.
• Likewise, turn on and test your wireless adapters one by one, to determine if problems are isolated to a single computer or common to all.
• Try ad hoc networking if infrastructure networking isn’t functional, and perhaps you’ll identify a problem with your access point or router.
• To help you work methodically, as you build your network, write down on paper the key settings like network name, WEP passkey, MAC addresses, and channel numbers (then eat the evidence afterward!).
• Don’t worry about making mistakes; you can go back and alter any of your WLAN settings any time.

Finally, don’t be surprised if your wireless LAN performance doesn’t match the numbers quoted by the manufacturer. For example, although 802.11b equipment technically supports 11 Mbps bandwidth, that is a theoretical maximum never achieved in practice. A significant amount of Wi-Fi network bandwidth is consumed by overhead that you cannot control. Expect to see more than about one-half the maximum bandwidth (5.5 Mbps at most for 802.11b, about 20 Mbps at most for the others) on your home WLAN.

Conclusion
Armed with the information contained in this tutorial, you’re now well on your way to building a working home WLAN. Welcome to the world of wireless networking!

From Bradley Mitchell,

• ease of installation
• total cost
• reliability
• performance
• security

About Wired LANs
Wired LANs use Ethernet cables and network adapters. Although two computers can be directly wired to each other using an Ethernet crossover cable, wired LANs generally also require central devices like hubs, switches, or routers to accommodate more computers.

For dial-up connections to the Internet, the computer hosting the modem must run Internet Connection Sharing or similar software to share the connection with all other computers on the LAN. Broadband routers allow easier sharing of cable modem or DSL Internet connections, plus they often include built-in firewall support.

Installation
Ethernet cables must be run from each computer to another computer or to the central device. It can be time-consuming and difficult to run cables under the floor or through walls, especially when computers sit in different rooms. Some newer homes are pre-wired with CAT5 cable, greatly simplifying the cabling process and minimizing unsightly cable runs.

The correct cabling configuration for a wired LAN varies depending on the mix of devices, the type of Internet connection, and whether internal or external modems are used. However, none of these options pose any more difficulty than, for example, wiring a home theater system.

After hardware installation, the remaining steps in configuring either wired or wireless LANs do not differ much. Both rely on standard Internet Protocol and network operating system configuration options. Laptops and other portable devices often enjoy greater mobility in wireless home network installations (at least for as long as their batteries allow).

Cost
Ethernet cables, hubs and switches are very inexpensive. Some connection sharing software packages, like ICS, are free; some cost a nominal fee. Broadband routers cost more, but these are optional components of a wired LAN, and their higher cost is offset by the benefit of easier installation and built-in security features.

Reliability
Ethernet cables, hubs and switches are extremely reliable, mainly because manufacturers have been continually improving Ethernet technology over several decades. Loose cables likely remain the single most common and annoying source of failure in a wired network. When installing a wired LAN or moving any of the components later, be sure to carefully check the cable connections.
Broadband routers have also suffered from some reliability problems in the past. Unlike other Ethernet gear, these products are relatively new, multi-function devices. Broadband routers have matured over the past several years and their reliability has improved greatly.

Performance
Wired LANs offer superior performance. Traditional Ethernet connections offer only 10 Mbps bandwidth, but 100 Mbps Fast Ethernet technology costs little more and is readily available. Although 100 Mbps represents a theoretical maximum performance never really achieved in practice, Fast Ethernet should be sufficient for home file sharing, gaming, and high-speed Internet access for many years into the future.
Wired LANs utilizing hubs can suffer performance slowdown if computers heavily utilize the network simultaneously. Use Ethernet switches instead of hubs to avoid this problem; a switch costs little more than a hub.

Security
For any wired LAN connected to the Internet, firewalls are the primary security consideration. Wired Ethernet hubs and switches do not support firewalls. However, firewall software products like ZoneAlarm can be installed on the computers themselves. Broadband routers offer equivalent firewall capability built into the device, configurable

Comparing wireless LAN technology with wired

About Wireless LANs
Popular WLAN technologies all follow one of the three main Wi-Fi communication standards. The benefits of wireless networking depend on the standard employed:

• 802.11b was the first standard to be widely used in WLANs.
• The 802.11a standard is faster but more expensive than 802.11b; 802.11a is more commonly found in business networks.
• The newest standard, 802.11g, attempts to combine the best of both 802.11a and 802.11b, though it too is more a more expensive home networking option.

Installation
Wi-Fi networks can be configured in two different ways:

• “Ad hoc” mode allows wireless devices to communicate in peer-to-peer mode with each other.
• “Infrastructure” mode allows wireless devices to communicate with a central node that in turn can communicate with wired nodes on that LAN.

Most LANs require infrastructure mode to access the Internet, a local printer, or other wired services, whereas ad hoc mode supports only basic file sharing between wireless devices.

Both Wi-Fi modes require wireless network adapters, sometimes called WLAN cards. Infrastructure mode WLANs additionally require a central device called the access point. The access point must be installed in a central location where wireless radio signals can reach it with minimal interference. Although Wi-Fi signals typically reach 100 feet (30 m) or more, obstructions like walls can greatly reduce their range.

Cost
Wireless gear costs somewhat more than the equivalent wired Ethernet products. At full retail prices, wireless adapters and access points may cost three or four times as much as Ethernet cable adapters and hubs/switches, respectively. 802.11b products have dropped in price considerably with the release of 802.11g, and obviously, bargain sales can be found if shoppers are persistent.

Reliability
Wireless LANs suffer a few more reliability problems than wired LANs, though perhaps not enough to be a significant concern. 802.11b and 802.11g wireless signals are subject to interference from other home applicances including microwave ovens, cordless telephones, and garage door openers. With careful installation, the likelihood of interference can be minimized.
Wireless networking products, particularly those that implement 802.11g, are comparatively new. As with any new technology, expect it will take time for these products to mature.

Performance
Wireless LANs using 802.11b support a maximum theoretical bandwidth of 11 Mbps, roughly the same as that of old, traditional Ethernet. 802.11a and 802.11g WLANs support 54 Mbps, that is approximately one-half the bandwidth of Fast Ethernet. Furthermore, Wi-Fi performance is distance sensitive, meaning that maximum performance will degrade on computers farther away from the access point or other communication endpoint. As more wireless devices utilize the WLAN more heavily, performance degrades even further.
Overall, the performance of 802.11a and 802.11g is sufficient for home Internet connection sharing and file sharing, but generally not sufficient for home LAN gaming.

The greater mobility of wireless LANs helps offset the performance disadvantage. Mobile computers do not need to be tied to an Ethernet cable and can roam freely within the WLAN range. However, many home computers are larger desktop models, and even mobile computers must sometimes be tied to an electrical cord and outlet for power. This undermines the mobility advantage of WLANs in many homes.

Security
In theory, wireless LANs are less secure than wired LANs, because wireless communication signals travel through the air and can easily be intercepted. To prove their point, some engineers have promoted the practice of wardriving, that involves traveling through a residential area with Wi-Fi equipment scanning the airwaves for unprotected WLANs. On balance, though, the weaknesses of wireless security are more theoretical than practical. WLANs protect their data through the Wired Equivalent Privacy (WEP) encryption standard, that makes wireless communications reasonably as safe as wired ones in homes.
No computer network is completely secure and homeowners should research this topic to ensure they are aware of and comfortable with the risks. Important security considerations for homeowners tend to not be related to whether the network is wired or wireless but rather ensuring:

• the home’s Internet firewall is properly configured
• the family is familiar with the danger of Internet “spoof emails” and how to recognize them
• the family is familiar with the concept of “spyware” and how to avoid it.
• babysitters, housekeepers and other visitors do not have unwanted access to the network

Which is better – wired or wireless?

Conclusion
You’ve studied the analysis and are ready to make your decision. Bottom line, then, which is better – wired or wireless? The table below summarizes the main criteria we’ve considered in this article. If you are very cost-conscious, need maximum performance of your home system, and don’t care much about mobility, then a wired Ethernet LAN is probably right for you.
If on the other hand, cost is less of an issue, you like being an early adopter of leading-edge technologies, and you are really concerned about the task of wiring your home or small business with Ethernet cable, then you should certainly consider a wireless LAN.

Many of you will naturally fall somewhere in between these two extremes. If you’re still undecided, consider asking friends and family about their experiences with building LANs.

Bradley Mitchell

Connecting Two Computers Directly With Cable

The traditional method to network two computers involves making a dedicated link by plugging one cable into the two systems. Several alternatives exist for networking two computers in this manner:

• Ethernet crossover cable
• Null modem serial cable or parallel peripheral cable
• Special-purpose USB cables
• Ethernet – Of the above choices, the Ethernet method is preferred as it supports a reliable, high-speed connection with minimal configuration required.

Additionally, Ethernet technology offers the most general-purpose solution, allowing networks with more than two computers to be built fairly easily later. If one of your computers possesses an Ethernet adapter but the other has USB, an Ethernet crossover cable can still be used by first plugging a USB-to-Ethernet converter unit into the computer’s USB port.

Serial and parallel
This type of cabling, called Direct Cable Connection (DCC) when using Microsoft Windows, offers lower performance but offers the same basic functionality as Ethernet cables. You may prefer this option if you have such cables readily available and network speed is not a concern. Serial and parallel cables are never used to network more than two computers.

USB
Ordinary USB cables must not be used to connect two computers directly to each other. Attempting to do so can electrically damage the computers! However, special USB cables designed for direct connection exist that can be used safely. You may prefer this option over others if your computers lack functional Ethernet network adapters.

To make dedicated connections with Ethernet, USB, serial or parallel cables requires

• each computer have a functioning network interface with an external jack for the cable, and the network settings on each computer appropriately configured
• One phone line or power cord cannot be used to directly connect two computers to each other for networking.

Connecting Two Computers With Cable Through Central Infrastructure

Rather than cable two computers directly, the computers may instead be joined indirectly through a central network fixture. This method requires two network cables, one connecting each computer to the fixture. Several types of fixtures exist for home networking:

• Ethernet hubs, switches, and routers
• USB hubs
• Phoneline and powerline wall outlets

Implementing this method often entails additional up-front cost to purchase more cables and network infrastructure. However, it’s a general-purpose solution accommodating any reasonable number of devices (e.g, ten or more).

You will likely prefer this approach if you intend to expand your network in the future.
Most cabled networks utilize Ethernet technology. Alternatively, USB hubs can be employed, while powerline and phoneline home networks each offer their own unique form of central infrastructure. The traditional Ethernet solutions are generally very reliable and offer high performance.

Connecting Two Computers Wirelessly
In recent years, wireless solutions have enjoyed increasing popularity for home networking. As with cabled solutions, several different wireless technologies exist to support basic two computer networks:

• Wi-Fi
• Bluetooth
• infrared

Wi-Fi connections can reach a greater distance than the wireless alternatives listed above. Many newer computers, especially laptops, now contain built-in Wi-Fi capability, making it the preferred choice in most situations. Wi-Fi can be used either with or without a network fixture. With two computers, Wi-Fi networking minus a fixture (also called ad-hoc mode) is especially simple to set up.

Bluetooth technology supports reasonably high-speed wireless connections between two computers without the need for a network fixture. Bluetooth is more commonly used when networking a computer with a consumer handheld device like a cell phone. Most desktop and older computers do not possess Bluetooth capability. Bluetooth works best if both devices are in the same room in close proximity to each other. Consider Bluetooth if you have interest in networking with handheld devices and your computers lack Wi-Fi capability.

Infrared networking existed on laptops years before either Wi-Fi or Bluetooth technologies became popular. Infrared connections only work between two computers, do not require a fixture, and are reasonably fast. Being very simple to set up and use, consider infrared if your computers support it and you lack the desire to invest effort in Wi-Fi or Bluetooth.

If you find mention of an alternative wireless technology called HomeRF, you can safely ignore it. HomeRF technology became obsolete several years ago and is not a practical option for home networking.