Cut the cord with Agere Wireless USB Client systems

Agere's Wireless USB Client product simplifies deployment on large user networks. To help you make the transition, Jim Boyce discusses configuration options and optimization techniques to get the most out of your new wireless network.

Networking might be a lot more common than it was 10 years ago, but it still isn’t any easier to accomplish. As new technologies emerge, many of us in the trenches have had to brace ourselves—again—for the slippery slope of the learning curve. When you combine a new operating system such as Windows XP and a relatively new technology such as wireless networking, it can be an educational experience, to say the least. To help you make the transition, I’ll explain the ins and outs of configuring a wireless network with Agere Systems' ORiNOCO Wireless USB Client.

Look Mom, no wires!
Agere Systems Inc. is a major player in the wireless networking market. Agere, which spun off as a separate company from Lucent Technologies (formerly AT&T) in June of 2002, offers a range of wireless access products for everything from the backbone to the end user. The focus of this Daily Drill Down is Agere’s USB Client, but you can’t really cover client configuration without looking in some detail at access points and related topics such as range and security. I’ll start with a look at the USB Client and then work up the chain.

The ORiNOCO USB Client is an 11-Mbps desktop unit that connects to the computer’s USB port with a standard USB cable. If you open up the USB Client unit, you’ll find that the unit contains Agere’s wireless PC Card with integral antenna and the hardware and firmware needed to adapt it to a USB connection. If you pop open one of Agere’s access points, you’ll find something similar: a wireless PC Card with the necessary support hardware and firmware. These are the same PC Cards you would use in a notebook’s PC Card slot or in Agere’s PCI or ISA adapters for desktop systems. By standardizing on a single unit, Agere not only simplified the product line, but also cut its development and support costs, which should ultimately translate into better, less expensive products.

Choosing a USB Client over the PCI/ISA adapter means you don’t need to worry about available slots or IRQs, and the unit doesn’t need a separate power supply. Just one cable hooks it all up. The USB Client offers another advantage over the PCI/ISA implementation for workstations installed under a desk: In many cases you’ll find that you need to add an optional antenna for PCI/ISA installations, particularly if the desk is metal. Using a USB Client lets you easily locate the unit on top of the desk where its range will be greater, which translates into better performance.

To connect to a wireless network, the client requires an access point. Like many of the wireless client products available today, Agere’s USB Client can connect to any 802.11b (Wi-Fi) compliant access point or residential gateway. This includes Agere’s Access Point, Access Server, and Residential Gateway products, as well as its older 2-Mbps and Turbo access point products. It also supports competing access points from companies such as Boingo, Nomadix, Linksys, D-Link, and others.

Actually connecting the unit is easy—after all, it only has one cable. Getting to the point of plugging in the cable takes a bit of setup, however, because you’ll need to install the drivers for it before you connect the unit. Although Windows XP includes built-in drivers for the ORiNOCO wireless clients, you should still download and install the latest version rather than rely on the bundled drivers. You’ll also need to download the software if you’re installing the USB Client under other operating systems. You’ll find the drivers at Agere’s Web site. Just click on the Support link and then the Wireless LAN Drivers link. Click the Drivers for Windows link to download a ZIP file containing the drivers.

After you download the software, extract the file to a folder and run Setup.exe. Installation varies a bit depending on your operating system, but in all cases you won’t have to do much besides specify the installation directory. When Setup is finished, you’ll find a signal status icon on the tray, which initially shows no device connected. Plug in the USB Client and wait a few seconds for the system to find the device. The system will tell you it has found a new networking device, install it, and then tell you it’s ready to use. Now it’s time to start configuring its settings.

Configuring network settings
The operating system determines the configuration options and methods you have for the USB Client. On all systems, Setup installs a Client Manager application you can use to view the card’s status, choose a configuration profile, run diagnostics, and perform other configuration and testing tasks. Client Manager’s Status area indicates the name of the connected network, signal strength, access point name, channel, and encryption status.

On Windows XP systems, Client Manager relies on the operating system’s built-in wireless network configuration tools. On Windows 2000 and earlier systems, Client Manager provides its own wizard for configuring settings. Let’s take a look at Windows XP first.

Windows XP configuration
On a Windows XP system, you can open the Network Connections folder, right-click the Wireless connection, and choose Properties to open the Wireless Networks tab of the connection’s property sheet (see Figure A).

Figure A

You can also navigate to the Wireless Networks tab by double-clicking the status icon on the tray to open the Client Manager status dialog, and then choosing Add/Edit Configuration Profile.

The Wireless Networks tab includes the following settings:
  • Use Windows To Configure My Wireless Network Settings: This option allows Windows XP to automatically configure the wireless network. If you prefer to configure the settings yourself, clear this check box.
  • Available Networks: This lists all of the available wireless networks detected by Windows XP. To configure the settings for a particular wireless network, select it here and click Configure.
  • Preferred Networks: Where you have multiple wireless access points available, this list shows your connection preferences. Windows XP attempts connection to the network in the order in which the networks are listed. Use the up/down arrows to change the preference order.
  • Advanced: Click Advanced to open the Advanced dialog box, which lets you set the following options:
    1. Any Available Network (Access Point Preferred): Use this option to allow Windows XP to connect to any available wireless network. It attempts connections to access point networks first. These are also called infrastructure networks. If Windows XP can’t find an infrastructure network, it attempts a connection to an ad hoc network (computer-to-computer) if one is available.
    2. Access Point (Infrastructure) Networks Only: Select this option to prevent Windows XP from connecting to an ad hoc network if an infrastructure network isn’t available.
    3. Computer-To-Computer (Ad Hoc) Networks Only: Select this option to prevent Windows XP from connecting to infrastructure networks, and to connect only to ad hoc networks. If no ad hoc networks are available, the connection fails.
    4. Automatically Connect To Non-Preferred Networks: Select this option if you want Windows XP to attempt a connection to a network even if it isn’t listed in the Preferred Networks list.

To configure a specific wireless network, select it in the Available Networks list and click Configure to open the Wireless Network Properties dialog box (see Figure B).

Figure B

The available settings are:
  • Network Name (SSID): This field specifies the Service Set Identifier (SSID), which uniquely identifies the wireless network. In most cases, you won’t change this value unless an automatically detected access point has changed names or you incorrectly entered the SSID for a manually added network.
  • Data Encryption (WEP Enabled): Select this option to encrypt the data moving between the client and access point (or other wireless device). Your data is susceptible to interception without encryption, so you should enable this option.
  • Network Authentication (Shared Mode): With this option selected (Shared Key Authentication mode), Windows XP uses the network key to authenticate the connection. With this option deselected (Open System mode), Windows XP does not authenticate the connection.
  • Network Key: If you’re not using a key provided by the device, enter the key in this field based on the key length specified by the Key Length field.
  • Key Format: Use this option to select between ASCII and hexadecimal formats for the key.
  • Key Length: Select the key length, either 40 bits or 104 bits.
  • Key Index (Advanced): Use this spin control to select the location of the key.
  • The Key Is Provided For Me Automatically: Choose this option to let Windows XP use the network key provided with the device.
  • This Is A Computer-To-Computer (Ad Hoc) Network: Select this option to identify the connection as an ad hoc connection rather than an infrastructure (access point) connection.

If the access point or ad hoc connection you want to use doesn’t show up in the Available Networks list, either the connection isn’t available or it is configured not to broadcast its SSID. As I’ll explain a bit later, hiding the SSID is a step you can take to secure your wireless network. In these cases, you can add the connection manually. To do so, click Add on the Wireless Networks tab to open a dialog box for the connection. Specify the SSID and other properties and click OK.

Other operating systems
Agere provides a wizard for configuring the USB client on operating systems other than Windows XP. To run the wizard, double-click the Client Manager icon on the tray or open it from the Start menu. The Client Manager displays the current settings profile, named Default. You can modify this profile or create additional profiles for additional wireless networks. To modify a profile, choose Actions, Add/Edit Configuration File. Select the profile from the drop-down list and click Edit to start the configuration wizard.

In the wizard, you specify the profile name and choose a network type, whether it’s access point, residential gateway, or peer-to-peer group (ad hoc). Next, specify the SSID for the network or click Scan to scan for available wireless networks. In the third wizard page, you enable or disable data encryption and specify the key and format. The fourth page lets you turn on or off power management for the client. The final page lets you configure the connection to renew its IP address when the profile is selected. You should enable this option if each of the wireless connections you use offers a different IP address range.

Running diagnostics
The Client Manager software includes some diagnostic tools you can use to test the card and monitor your wireless connections. You access these from the Advanced menu in the Client Manager. The Card Diagnostics perform several tests on the card, driver, and firmware. Keep in mind that testing the card temporarily disconnects it from the network.

The Link Test (see Figure C) provides a comprehensive look at signal and noise levels for the connection. The software identifies the stations by their MAC addresses; shows signal, noise, and SNR values; and offers several graphing options for analyzing the results. You can also configure logging for the connection and turn logging on and off.

Figure C

The Site Monitor (see Figure D) gives you a means for analyzing properties for available wireless networks. These properties include MAC address, signal strength, noise level, channel, and others. Selecting the properties to monitor is as easy as selecting the items from a drop-down list. The Site Monitor is handy not only for identifying potential problems, but also for monitoring multiple access points to find the one with the best performance.

Figure D

Extending network range
One problem you will experience sooner or later is lack of signal strength. I’ve tested several devices from Agere and other manufacturers in different deployment scenarios and have had generally good results. In a few situations, I’ve had to make some changes to get enough signal strength to make the network useable. You can make some of these changes at the client side, but some need to be made at the access point. In other situations, you might have to make each change at both sides of the connection.

First, the USB client doesn’t have to be tucked under the desk like a PCI/ISA implementation. You can set the unit on the desktop or even on a shelf to get it away from power cords, monitors, speakers, and other components that generate EMF interference. If need be, add a longer USB cable to get the unit further away from the computer and interference. The same holds true for the access points, so carefully consider placement when you install them.

As I’ve already mentioned, the ORiNOCO units use the same PC Card internally. The PC Card contains an integrated antenna, but the unit also has a jack for an optional external antenna, which Agere manufactures as well. In many situations, you can obtain better signal strength and therefore better performance by adding an antenna. The only situation in which you can do so without voiding your warranty, however, is when you’re using the PC Card in an implementation where the antenna jack is readily accessible. For example, it’s no problem to plug in the antenna if you’re using the PC Card in a notebook computer or a PCI/ISA adapter. The reason you void the warranty in other situations is that you have to drill a hole in the case for the antenna wire.

To use an external antenna with the USB Client (remember the voided warranty), first unplug the unit from the computer. Then, grasp the unit by the base and gently pull off the cover. Locate the antenna jack in the end of the PC Card. Drill a hole in the top of the plastic cover of sufficient size to accommodate the antenna’s plug. Pass the plug through the hole, plug it into the PC Card, and replace the cover. Plug the unit back into the computer to see if you’ve gained sufficient additional strength. Experiment with antenna placement as you monitor the signal strength, keeping the antenna wire away from power cords and other EMF-generating devices.

Check out your access points for optional antenna support. Many provide antenna jacks, but others—such as the ORiNOCO Residential Gateways (RG)—do not. The ORiNOCO RGs use the same PC Card as the USB Client, so you can use the same type of external antenna with them as with the client. The RGs provide no external antenna connection on the case, so you’ll have to open them and drill a hole in the cover to accommodate the antenna.

A final word on securing the network
No article on wireless would be complete without a few tips on security. There are several things you can and should do to secure your wireless networks. This is particularly important in a business setting where you have confidential information being transferred on the network, but it can also be important for another reason: keeping unauthorized users off your network. It’s not impossible for an enterprising person in the business next door to gain access to your network and Internet connection if your network isn’t properly secured.

One of the first steps to take is to change the default SSID for your access points to something that isn’t easy to guess. Better yet, turn off SSID broadcast, which requires that the client know the SSID. This provides the benefit of better security, but unfortunately means users can’t scan for the wireless connection. This, in turn, might mean more support calls to help new users find the connection.

Another step you can take on the access point side is to change the default community string for the access point’s SNMP management. Many default to using the ubiquitous string public, so you should change it to an arbitrary string.

It’s also important that you use data encryption for the wireless network as I discussed previously. Enable the Network Authentication option to provide additional security. Finally, you can decrease the chances for unauthorized users to gain access by not using DHCP for wireless connections. Specify static IPs for the clients, and choose an arbitrary subnet rather than the common 192.168.0.n or 10.0.0.n networks. Keep in mind that this strategy becomes impractical as the number of clients grows, but it can be effective for small networks.

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