Wi-Fi

Build Your Skills: Connecting an iPAQ to a corporate network

Get the most benefit out of your iPAQ by establishing connectivity both to the Internet and to your corporate network.

Few people would deny that an iPAQ is a handy device. To get the most benefit out of your iPAQ, though, you’ll want to establish connectivity both to the Internet and to your corporate network. There are a number of ways to establish such connectivity, but the biggest challenges of doing so involve being able to establish a mobile connection that is also secure. Here are some of the various connectivity options that are available.

Connectivity
Most iPAQ users connect their iPAQs to the Internet. You can also connect to your corporate network by using a VPN link. This allows you to access files stored on network servers, access your e-mail, or even initiate a terminal server session, in which you can run full-blown network applications. The trick to accomplishing all of this is to be able to connect first to the Internet and then to your corporate VPN.

The newer iPAQs offer two built-in connectivity options, including Wi-Fi and BlueTooth. At first, Wi-Fi may seem like the obvious connectivity choice, but using Wi-Fi has both its good and bad points. The biggest things that Wi-Fi has going for it are speed and availability. The 802.11B standard offers theoretic speeds of up to 11 Mbps, although actual speeds are usually closer to 5 Mbps. Even so, 5 Mbps is usually plenty of speed for surfing the Internet.

From an availability standpoint, Wi-Fi is pretty much ubiquitous. Most airports, hotels, and libraries have implemented public access 802.11 networks. These are great for the business traveler who needs to access the Internet while on the go.

The main problem with using a Wi-Fi connection is that although many public facilities have access points in place, the coverage is still very much lacking. For example, it's currently impossible to open a Wi-Fi connection at the airport and maintain that connection all the way to a meeting on the other side of town. The last time I was in Los Angeles, a friend was showing me that his ISP delivered Internet to his home by way of Wi-Fi. The ISP had constructed large towers capable of delivering Internet access to the entire city. Even so, such towers presently exist only in the largest cities, and Internet access is available only to subscribers, not to the businessman who's in town for only a few days.

Another problem with using Wi-Fi is security. I've found that, although wireless connections are inherently insecure, they can be made relatively secure. I don’t believe that's the case with an iPAQ, though. Although the iPAQ supports WEP encryption, it lacks the flexibility of a full-fledged PC that would allow you to implement other security mechanisms, such as third-party encryption or filtering software. Just for the sake of argument, suppose for a moment that WEP encryption did offer sufficient security. Security would still be lacking because most public access points don’t use WEP or any other form of encryption.

Your other connection alternative is BlueTooth. As you probably know, BlueTooth is a personal area networking (PAN) technology. This means that a BlueTooth connection has a maximum range of about 22 feet. Obviously, a 22-foot range isn’t enough to give you any sort of mobility beyond a single room. Therefore, you'll need to use a second device to establish the connection. In most cases, the device of choice is a cell phone.

A cell phone overcomes the range limitations associated with Wi-Fi and tends to be much more secure. The problem is that a cellular data connection tends to be really slow. In order to achieve the best possible data rates, I recommend using a GPRS phone.

GPRS stands for General Packet Radio Service. The speed of a GPRS connection varies widely. A GPRS network can use one of four channel codings and up to eight different time slice data rates. What this means is that, depending on which channel coding and time slice your cellular provider uses, the GPRS network may be as slow as 9 Kbps or as fast as 171.2 Kbps. As you can see, even the fastest GPRS connection is nowhere near as fast as a 5 Mbps Wi-Fi connection. But it's several times faster than a 56 Kbps dial-up connection.

Unfortunately, speed isn’t the only problem associated with using a GPRS connection. There's also the issue of cost. Using a GPRS connection requires you to purchase a GPRS-compatible cell phone that also supports BlueTooth. Then, of course, you have those monthly cell bills. Many of the cellular providers that offer GPRS have a base rate, plus an additional charge based on how much data flowed across the connection.

Another problem is compatibility. Not all GPRS-based phones are BlueTooth compatible, and even fewer support VPN over GPRS. If you decide that you want to connect to the Internet by piggybacking off a cell phone, then I recommend checking out the GSM World Web page for GPRS terminals. This page lists all of the GPRS-compatible phones that are or will soon be available and contains links to related Web sites.

An easier alternative?
So far, I've explained that you can use the iPAQ’s built-in communications mechanisms to either connect to a Wi-Fi network or to establish a BlueTooth connection to your cell phone. However, these aren’t your only connectivity options. Depending on the model of your iPAQ, you might be able to take advantage of one of Hewlett-Packard’s various expansion packs and connect to the Internet in a different way. You can find a list of the expansion packs that are available by going to HP's Web site.

On the Web site, HP offers a Wireless Pack for GSM/GPRS networks. By using this device, you'll be able to connect your iPAQ directly to a GPRS network without the aid of a cell phone. This device is not yet available but, according to the HP Web site, it will be soon and will sell for about $349.

HP also makes an expansion pack that will allow your iPAQ to accept PC cards (if it doesn’t already). Having the ability to insert a PC card into your system gives you several more possibilities for connecting your iPAQ to the Internet or to a corporate network. Many cellular manufacturers offer PC card-based cellular modems. The conditions applying to such modems vary depending on your cellular provider. In many cases, though, a cellular modem is considered by the cellular provider to be a cell phone. It has a different phone number from your voice phone, and you'll receive a separate bill for it.

The trick to buying a cellular modem for your iPAQ is to find one that includes Windows CE (Pocket PC) drivers. Remember that many of these devices are intended more for laptops than for an iPAQ. The reason for this is because of power consumption; cellular devices tend to consume a lot of power and can drain an iPAQ’s batteries rather quickly. If you're interested in extending your battery life, you're much better off using a BlueTooth connection to a cell phone, because a BlueTooth connection consumes much less power than a cellular connection.

As I talk about cellular connections, I'd be negligent if I didn’t tell you that GPRS is not the only type of connection available. Sprint PCS offers a technology called 3G. The 3G network offers data speeds of up to 400 Mbps. Sprint does offer 3G cellular modems, but I've been unable to find any information on whether they include Windows CE drivers or if they're VPN compatible.

One benefit to using Sprint’s 3G network is that Sprint charges a flat rate for data access. I use Sprint PCS for my own mobile Internet needs. I simply pay a few extra dollars per month on top of my normal phone bill, and I get unlimited Internet access. In case you’re wondering, though, I’m not using an iPAQ. Instead, I'm using a Sprint phone that already has Windows CE integrated into it. It's similar to an iPAQ with a built-in 3G network connection.

Making the connection
Now that I've explained the various technologies you can use to establish a connection between your iPAQ and the Internet, I want to talk about the technique for putting everything together. The instructions that I’m about to give you assume that you're using the iPAQ’s BlueTooth connection to connect to a GPRS phone, and that such a connection already exists.

In this scenario, the GPRS phone then connects to the Internet on the iPAQ’s behalf. Once the Internet connection is established, a PPTP link is used to connect to your company’s VPN. Keep in mind that if your GPRS phone doesn’t support BlueTooth or PPTP, then the procedure that I'm about to show you won't work. This procedure also assumes that you've already figured out how to attach your iPAQ to the Internet via the BlueTooth connection to the GPRS phone.

The first thing you must do is determine whether you need HP’s VPN/IMAP4 fix. If you're using an iPAQ 3970 with ROM version 2.0, then you don’t need the fix. If you're using anything older than that, you should go to HP's iPAQ VPN Patch Web site to get the fix.

Once you've downloaded the fix and applied it to your iPAQ, select the iPAQ’s Settings | Connections menu option. When you see the Connections properties sheet, select the Connections tab. Now locate the drop-down list in the middle of the screen. This drop-down list will have the following text above it: When Needed, Automatically Connect To Work Using These Settings. Select the New option from the list and then enter a name for your settings in the space provided. You can name the connection anything you'd like. One point to remember is that you're entering a name for a group of settings, not for a specific VPN connection. Therefore, I recommend naming the settings something like “VPN.”

After assigning a name to the VPN settings, you’ll be asked to enter a name for the connection and for the destination IP address. The connection name should be something that reflects the name of the company or location that you're connecting to.

After entering this information, the iPAQ will return you to the Settings properties sheet. If your company is using a proxy server, you must select the Proxy Settings tab and enter the settings specific to your company’s proxy server. You should now be able to connect to your company’s VPN.

Troubleshooting
There have been a lot of reports on the Internet indicating that the iPAQ tends to drop its VPN connection for no apparent reason during the middle of a session if you're surfing the Internet. Fortunately, there's a fix available for the problem.

Before you implement the fix, I recommend testing to see if you're even affected by the problem. Remember that the problem is probably tied to specific models of the iPAQ. Also, the fix involves editing the registry, a task that can cause a lot of trouble for Windows and/or your applications. Therefore, I suggest making a full backup of your iPAQ prior to attempting the fix.

The iPAQ doesn’t have a built-in Registry Editor, so you'll have to download one. I recommend that you download a utility called PHM Registry Editor. Once you've installed the utility, you should test your VPN connection one last time. If you're unable to establish a VPN connection, the fix that I'm about to show you won’t help.

Once you've verified that you can connect to the VPN, but that the connection tends to drop for no reason, go back to the Proxy Settings tab mentioned earlier. You should do this even if you aren’t using a proxy server. Select the This Network Connects To The Internet check box. Next, select the This Network Uses A Proxy Server To Connect To The Internet check box. Finally, enter the word clearme as the name of the proxy server.

When you’ve finished with the proxy server configuration, verify that you can still connect to the VPN. Don’t bother trying to browse the Web, because it won’t work right now. Once you've verified connectivity, disconnect from the VPN and then open the Registry Editor. Navigate through the Registry to

HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\InternetSettings

There are several keys beneath this branch that you'll want to edit. Start out by setting the ProxyEnabled key to 0. Next, set the ProxyHttp 1.1 key to 0. Now, verify that the ProxyOverride key is empty, and clear it if necessary. Finally, clear the value of the ProxyServer key, but don’t delete the key itself.

Now, navigate to

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Media Player 8\Streaming

Set the value of the UseProxy key to 0.

The last part of the process is to go to the top of the registry and search for the value clearme. You should find two keys containing the clearme value. Both of these keys will be named Proxy. Delete the value from these keys, but do not delete the keys themselves. Finally, exit the Registry Editor and soft-boot the machine. When the iPAQ restarts, you shouldn't have the problem of random VPN dropouts.
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