Sarasota PC Monitor
Tech Talk (11/01)
Wireless Networking
(With further comments on Windows XP)
by Brian K. Lewis, Ph.D.*
Member of the Sarasota Personal Computer Users Group, Inc.It's really amazing just how much information is showing up on wireless networking. It seems like every manufacturer has decided this is the wave of the moment. There are systems that allow wireless connection to existing wired networks and systems that don't need any wired connections. It is relatively simple and inexpensive to setup a fully wireless system for a small office or home office. By this I mean a system with less than five computers. And, if you have a dial-up, DSL or cable modem connection, you can set up Internet connection sharing (ICS). The requirement being that the computer directly connected to the Internet is running Win98SE, ME or XP.
The current wireless protocol that is most widely available is 802.11b or WiFi. This is the protocol I used for setting up a small wireless network. This protocol transmits at speeds from 1Mbps to 11Mbps. The latter speed makes it comparable to a wired Ethernet connection. The wireless hardware is advertised as working with distances of 150 to 500 ft. However, I would suggest some careful planning as the farther away the systems are from each other, the lower the signal strength. Naturally, at lower signal strength, you will have more problems making and keeping a connection. One manufacturer has a signal strength table that shows maximum signal at 75 meters in an open area and 25 meters through multiple walls.
In setting up a wired connection between computers, one of the major costs is laying the actual wires. In some office settings, it is very expensive, especially if you want to keep the wires out of sight and out of the way. The wireless hardware is more expensive than the Ethernet cards, but you don't have the wiring expense. So it is possible to end up with about the same costs in a network of five computers or less.
The system I installed used the SMC USB wireless units. These are external units that connect to the computers USB ports. Similar systems using PCI cards or PC cards for laptops are available from many different manufacturers. Intel, D-Link, 3Com, and Zoom Telephonics are examples of such manufacturers. Because the system had no wired network to deal with, I did not need to include an access point. Wireless Ethernet access point hardware increases the cost to almost double that of a totally wireless system. That is, unless you are looking at more than a 4-5 computer network. The two SMC units cost about $200.00 and that was the total cost of the network hardware and software. I actually did two different installations as I tested it with my office setup before I took to the client's office. That way I had a better idea of how it worked and what the problems might be. They were very few, I might add.
The USB connection, along with the Win98SE plug and play capability simplified the overall installation. Windows found the hardware on boot-up and asked for the installation disk. The installation software leads you through the initial settings for the network. These include the channel, security settings and operating mode which is "ad-hoc" for a totally wireless network. Once this installation is completed you still have to setup the network protocols in the Network Neighborhood. For internal networks, I would recommend setting up NetBEUI rather than TCP/IP. This is especially true for networks that access the Internet via dial-up, DSL or cable. Then the file and printer sharing should not be visible through TCP/IP to any computers outside of the network. You will, of course, also have a firewall on the computer connected directly to the Internet.
You will also have to set up the computer name and workgroup under the Identification tab in the network properties. And finally, set up the file and printer sharing that you wish to do. If this is an office situation, you may want to password protect the access to the shared files.
Another aspect of setting up any kind of 802.11b wireless network is the security of the transmissions. Although you will find that signal strength drops off rapidly with increasing distance, it has been demonstrated that a good antenna can pick up wireless transmissions from a considerable distance. There was a very interesting article posted to "Extreme Tech" www.extremetech.com that demonstrated the vulnerability of wireless networks. For example, the authors logged 100 access points while driving a highway at 60 mph. About 40% of these had not enabled the WEP (wired equivalent privacy) protocol on their system. Many of the current wireless products allow you to enable a 128-bit encryption, which makes it less likely that any of your transmissions will be read outside your network.
There was also a New York Times article about a security expert who was using his laptop while waiting for his wife in a hospital. He noticed a green light blinking on the card he used to connect his laptop to the wireless network in his home. It seems that the hospitals 802.11b network was welcoming him and allowing him access to their network including the Internet connection. This access would probably have included patient-sensitive information entered by nurses via the wireless equipped laptops they carried with them from room to room. So, the point is, if you setup a wireless network, be certain to enable the 128-bit WEP encryption to keep other people out of your system. Also, don't buy hardware that doesn't have this capability.
For a small office/home office network, a wireless system can work quite well. Especially if you have a laptop that you wish to add occasionally to the network. In theory, you can add Internet connection sharing through a dial-up modem. However, in practice, I find this more difficult than using a cable modem as the shared device. Microsoft's Internet connection sharing requires a TCP/IP connection between the computers. What you have to check is to be certain that the file/printer sharing is not bound to this protocol or the ICS protocol.
If you don't have telephone connections close to your computers, or if you want to be able to have some portability, such as with a laptop, then wireless may be your best choice. It certainly is faster than the 2Mbps telephone line network systems. You just have to be certain that you don't have too great a distance or too many walls between your wireless connected computers.
Now for another topic. Last month I indicated that I wasn't happy with Microsoft's new operating system, Windows XP. I still am not happy with many things, especially the home version of XP. I find that I am not alone in my concerns. In recent weeks I have been joined by such distinguished company as Brian Livingston the author of Infoworld's "Window Manager" column and "Windows Secrets" books. He has stated that he will not use XP, nor will he write a new book on Windows XP. In fact he considers XP to be a downgrade, rather than an upgrade. In the October 30 issue of PC Magazine, Bill Machrone, VP of Technology for Ziff Davis Media also warns readers not to upgrade to the home edition of XP. If you upgrade to XP, buy the professional edition and set up supervisor and user password protection. He also recommends using a firewall other than the one included with XP. Another voice that I've heard from is an article in Advisor magazine's Business Security. They agree that the "raw sockets" feature of XP poses a danger to the Internet by allowing spoofing of IP addresses. And, believe it or not, Scientific American in their October issue has an article on Internet worms, viruses and the problems of multiple zombies affecting Web servers. This article also points out the potential problems that XP's raw sockets can create by greatly increasing the number of zombies. The potential for damaging distributed denial of service attacks (DDoS) cannot and should not be ignored.
There has been some speculation that users will be able to buy multiple copies of Windows XP at a discount. However, as I write this article there is nothing to be found on Microsoft's XP Website that supports this rumor. Also, in the material I have received from Microsoft and other vendors there is no hint of a small quantity discount. Neither the resellers that are taking advance orders nor the wholesalers I have contacted will admit to any discount for individuals purchasing up to 10 copies of Windows XP, either home or professional version. So, we'll just have to see if this changes after the actual release date.
Some of my readers seem to think I was over-reacting to a remote threat that might exist with the widespread installation of Windows XP. Well, in light of the events of recent memory, I would prefer to over-react in my efforts to establish computer security, than to not respond to what I, and others, consider a serious threat to the Internet. I would rather be proven wrong, than have it happen and not have spoken my mind on it.
*Dr. Lewis is a former University and Medical School professor. He has more than 20 years of experience working with personal computer hardware and software. He can be reached via e-mail at brian_klewis@hotmail.com or voice mail at 941-925-3047. :
Copyright 2001. This article is from the November 2001 issue of the Sarasota PC Monitor, the official monthly publication of the Sarasota Personal Computer Users Group, Inc., P.O. Box 15889, Sarasota, FL 34277-1889. Permission to reprint is granted only to other non-profit computer user groups, provided proper credit is given to the author and our publication. We would appreciate receiving a copy of the publication the reprint appears in, please send to above address, Attn: Editor. For further information about our group, email: admin@spcug.org/ Web: http://www.spcug.org/The Sarasota Personal Computer Users Group, Inc. has 1,300+ members and was established in 1982. We are members of the Assoc. of PC User Groups (APCUG), the Florida Assoc. of PC Users Groups, Inc., and we are members of the America Online Ambassador Program.
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