Mixing Wired and Wireless Networking in Your Home
Feb 26, 2002 12:00 PM, David Chernicoff
Although the idea of a completely wireless home network is compelling, in most cases, a mixed wired/wireless environment will serve your needs better. This week, I outline the basic differences between the two network topologies and give you some guidelines for using and combining them for the best performance.
The most obvious difference between wired and wireless networking is speed. Wired Ethernet is 100Mbps (100Base-T) or 10Mbps (10Base-T). Wireless Ethernet is either 11Mbps (802.11b) or 54Mbps (802.11a). Few people use 10BaseT any longer; 100Base-T has replaced it in almost every product. Most network hubs use auto-switching or auto-sensing; the hub can determine the highest performance available to the attached network card and can switch between the two speeds. 10Base-T and 100BaseT technologies are compatible with each other; with the appropriate hub, you can use them in mixed networks.
The two wireless Ethernet standards aren't compatible with each other. Select the standard you want to use and purchase appropriate equipment for all your computers. As I write this, 802.11a devices cost two to three times more than 802.11b devices. Although 802.11a and 802.11b standards are in place, you should purchase all your wireless equipment from the same vendor. Experience has shown me that mixing flavors of 802.11 devices and software can add significant complications. For this story's wireless testing, I used access points and client devices from Belkin Components.
In terms of network performance, wireless can't compete with wired networking, even when you compare 11Mbps wireless with 10Mbps wired. (The best you can hope for is equivalent performance, and you'll rarely receive that.) Wireless-network performance can vary widely from published specifications. My own experiences have convinced me to expect performances that are about half of the published performance specifications.
Even when a wireless network works properly, large file transfers are problematic. I hear numerous complaints from wireless users about copying large Outlook .pst files from a desktop to a notebook using a wireless link. As file size increases (greater than 100MB), wireless file transfers tend to fail.
The second difference between wired and wireless networks is convenience: Not needing to run wires is obviously an attractive proposition. But although wireless vendors want you to believe that wireless networking is as simple as plugging in their devices, the reality is quite different. To help, I've written an overview of wired and wireless networking configurations.
Wired and Wireless Networking Configurations
Before I outline a basic configuration for mixed wired and wireless networking, I'm going to make two presumptions: Your network is connected to the Internet, and you use the network for more than sharing Internet access. If you simply want to share an Internet connection among multiple computers, little can go wrong. Regardless of how fast your Internet connection is, it will be slower than even a slow wireless connection, so your bottleneck will always be that Internet connection. Because of the nature of networking, performance doesn't become a concern until you start moving files between machines on the internal network.
Ethernet is a shared-bandwidth technology: The available network bandwidth is divided by the number of users on that segment. Let's look at the math; an 11Mbps network pipe can move, at best, a little less than 1.4MB of data per second (the reality is that you'll rarely exceed more than 1MBps). A common bandwidth for LAN-based streaming video is 300Kbps, so at best, you can play four concurrent streams at full bandwidth. In reality, you'll likely be limited to three streams, presuming there isn't other network traffic.
How about playing music? The average MP3 track is about 3MB, so copying the MP3 file will take about 4 seconds if you have the wireless network to yourself. As you add additional traffic, the copy time increases. If you're playing streaming audio, you have the same problem as when you play streaming video: If you don't have enough bandwidth to play the stream you selected, you'll start to get drop outs, or the selection will stop playing.
A wired 100Mbps network gives you at least nine times the theoretical network bandwidth, but pulling network cable might not be practical or possible in your networking environment. The trick is to combine wired and wireless networking in a manner that maximizes the advantages of each, while minimizing the disadvantages. To help you, I'll walk you through a typical home-networking scenario using examples from my home-networking experiences.
For your wired network, use switched 100Mbps networking. Using a network switch, rather than a hub, can provide full 100Mbps bandwidth to each port on the box. Switches are available from several vendors for less than $200. Most business-grade computers come with a built-in 10/100 network card; otherwise, you can buy one for less than $25 from major vendors. Make sure that the switch you buy has enough ports for your existing network and any planned expansion.
For your wireless network, you might choose networking equipment according to what your company office uses if you transport your wireless-capable notebook between office and home. In my case, I swap wireless cards between home and office because my office wireless network uses a high-security model, which isn't necessary in my home. And swapping network cards (one shows up as Network Connection #2, the other as Network Connection #3, and their connection information is specific to each card) is easier than reconfiguring a card each time I switch wireless environments.
Now let's look at how to use your equipment. First, determine your wired network's central location, which might be the location of your file server or where your Internet connection enters the house—the more central the location, the better. (In my case, the central point is my home office because that's where my Internet connection and file servers are.) Then determine where your wired connections can reach.
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