A Broadband Primer for Telecommuters

One generalization we can make about computing is that over time, most technology items become cheaper, while at the same time, they become faster. This is true of broadband in its most common forms. Both Digital Subscriber Line (DSL) and high-speed Internet cable services are available to millions of business and residential users worldwide and are now cheaper and faster than ever. Which is better for your situation as a telecommuter depends on your needs as well as what you or your company is willing to pay.

DSL employs sophisticated modulation schemes to pack data onto copper wires and uses existing telephone lines to connect your home directly to your local phone company in order to link you to the Internet.

Satisfied users cite a variety of reasons for their approval of DSL. The direct connection between your phone and the phone company makes DSL very secure. DSL is just as reliable as your phone line, and it boasts speedy upload and download rates. Another advantage is that you can be online and on the telephone simultaneously.

When you sign up for DSL, your local phone company will usually offer you the option of installing the equipment yourself and will provide you with a modem to convert the phone company's data format to one that is compatible with your own network. They'll also provide one filter for each regular telephone in your home so that when someone is online, Internet traffic noise won't interfere with your phone conversations. What about the downsides of DSL?

A frequently cited disadvantage of DSL is that customers must be located within approximately three miles of the central telephone station. Another common complaint is that the signal can become degraded. As I mentioned, users have to install DSL filters onto their telephone jacks because the telephone lines carry both normal voice transmission and DSL signal frequencies. The presence of the DSL signal on all of the phone wires in the house (especially when several devices are connected to the line) causes the degradation. One way around it is to install just one filter upstream from all of the phone jacks except the one that connects to the DSL modem. Not an easy task, especially when you're faced with older household telephone wiring.

If you decide to go with DSL, you'll be given options as to the speed and type of your connection. The most popular is Asymmetric DSL, or ADSL, where the download rates exceed the upload rates, because most users tend to download more than they upload. Within ADSL, bandwidth speeds vary as well. For example, Verizon 's basic service downloads at 768Kbit/sec. and uploads at 128Kbit/sec. The next level of service that providers typically offer will download at 1.5Mbit/sec. and upload at 384Kbit/sec. The elite ADSL level provides downloads between 3Mbit/sec. and 5Mbit/sec. and uploads at 640Kbit/sec. to 1Mbit/sec. Not as popular for the home user is Symmetric DSL, which provides the same download and upload speeds. It's for businesses and power telecommuters who send and receive lots of data.

An increasingly popular alternative to DSL is to go online in your home office via cable lines. This option is available nearly everywhere you can sign up for cable television. Its appeal lies in the "always on" connection and, theoretically at least, very good connection speeds. Your local cable provider supplies a cable modem that connects to the cable line and an Ethernet cord that leads from the modem to your computer. The Internet provider station is connected to the cable company via fiber-optic cable. Then the cable company's fiber-optic line connects an entire neighborhood via the shared cable-modem connections.

Because access is shared among all enrolled computers in your neighborhood (it's like a LAN -- but it's for the whole community, not just your house), bandwidth may suffer, as can security. Bandwidth decreases as enrollment increases. While it is possible to attain downstream connections at 30Mbit/sec., in actuality, you're more likely to get 500Kbit/sec. to 700Kbit/sec. (and 128Kbit/sec. upstream). In general, you'll realize much slower upload speeds compared with download speeds. And having a shared network inherently reduces the security of each individual on the network.

Both DSL and cable-modem connections enjoy widespread popularity, so you'll have to weigh the pros and cons according to your individual needs. And you may not even have to make a decision -- it's possible that only one is available in your neighborhood.

Douglas Schweitzer is a freelance writer and Internet security specialist in Nesconset, N.Y. Contact him at dougneak@juno.com.


Copyright © 2006 IDG Communications, Inc.

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