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DSL or Cable:

by Adam Erickson

You're well aware of the problem, of course: You spend 20 minutes trying to connect to the Internet. You have time to go make (and then drink) a pot of coffee while waiting for a Web page to display. You've given up altogether on downloading the latest music because by the time you get a song downloaded, the band has broken up (or possibly retired).

If all of this sounds familiar, this article is for you. Read on to learn about high-speed DSL (Digital Subscriber Line) and cable connections as practical alternatives to the frustrating world of dial-up. We'll tell you what you need to know to choose the right connection for your needs, and once you've made your choice, we'll tell you how to get hooked up.

You already know that the Internet is painfully slow on a dial-up connection, and one prescription for your pain is DSL. But exactly what is DSL, and in what ways is it different from a regular phone line?

A standard telephone line is referred to by telephone companies as POTS (Plain Old Telephone Service). This POTS line is an analog line that can carry a limited amount of voice or data traffic. This limit is evident to anyone who has a 56K (56Kbps, or kilobits per second) modem, because such modems usually connect at an actual maximum speed of between 40 Kbps and 48Kbps. DSL uses your existing copper telephone wires to deliver high-speed Internet access. When you sign up for DSL, your local phone company changes your POTS line to a digital line. A digital line permits for data rates of 5Mbps (megabits per second) or higher, over the same wires that used to top out at 40 to 49Kbps. However, data rates in the megabit range are unusual (and expensive). Instead, most residential DSL customers will receive data rates of roughly 384Kbps. (Still, 384Kbps is at least 10 times the speed you're currently getting with your 56K modem.)

A DSL connection requires that a router be connected to the phone line in your home. The router has an IP (Internet protocol) address, which, just like your home postal address, tells others (in this case, other computers) where to find you. Because the router is always connected to your computer, as long as both the computer and router are turned on, you're always connected to the Internet. This is different from a dial-up scenario; in that case, you temporarily use the IP address of whichever computer your modem connects to at your ISP (Internet service provider).


Another important feature of DSL is the data rate you pay for is exactly what you get. If you sign up for DSL at 384Kbps, your line is allocated exactly 384Kbps. Other factors, such as the quality of the phone lines between your computer and your ISP, can sometimes degrade the connection, but the bandwidth you pay for is yours and yours alone. This is different from cable Internet connections, which we'll discuss next.

Cable Internet access is another high-speed option in which, as you've probably guessed, your local cable company uses your cable television wires instead of a phone line to connect you to the Internet.

You may wonder how this is possible. We're all accustomed to using the phone to talk from person to person, so it's not hard to understand that a computer could talk to another computer over a phone line. But how can a computer talk to other computers using cable television?

Actually, the answer is simple. No matter what data is being transferred along a wire, it's really just an electronic signal. It's up to the equipment at each end of the wire to decode that signal and to decide what to do with it. The reality is that the cable companies are ultimately connected to the same international fiber-optic system as everyone else; they just deliver data to your house via a different medium. It's this different medium that lets them offer another alternative to Internet connectivity.

Shared bandwidth
Perhaps the most significant difference between DSL and cable Internet access is the fact that cable is essentially a shared-bandwidth technology. In other words, with DSL service, you're allocated a certain fixed amount of bandwidth. This bandwidth will never decrease or increase; you paid for that bandwidth, and it's all yours. But with a cable modem, you aren't guaranteed exclusive access to the total available amount of bandwidth. Because of the way cable networks are set up, there may be times when you're able to use a full 6Mbps of bandwidth, but there may be other times you are limited to 256Kbps or 128Kbps, or whatever happens to be available.


Here's why. With cable Internet service, an access point is shared by everyone within a certain area. Although maximum throughput varies depending on the equipment used, this access point generally provides about 10Mbps of bandwidth. If no one else within your access point area is on the Internet, you have the full 10Mbps to yourself, even if your service is only supposed to offer, say, 384Kbps. However, if many people are online, your connection will slow down. If this slowdown occurs regularly, the only solution is for the cable company to install another access point. Of course, you may or may not be able to compel the provider to add that additional access point. That's one of the risks of using cable.

Security risks
A shared access point also carries some special security risks. Essentially, every computer that uses that access point for Internet access is part of the same network. In effect, this network functions like the LAN (local-area network) you probably have at work, which makes it easy to share files and access other computers within the network. This configuration is great in the office, where you generally want everyone to be able to share certain resources. But it's not so great at home: Your last year's tax returns could end up being shared with everyone in your neighborhood. To avoid this scenario, be sure to disable file sharing on your computer. To do so, follow these steps:

  • Go to the Start button and select Settings.
  • Choose Control Panel.
  • Double-click the Network icon.
  • Click the File And Print Sharing button.
  • Uncheck the File Access and Print Access checkboxes.

Cable modems and routers
Cable Internet access requires that a cable modem be installed in your house. From an end-user's perspective, a cable modem functions the same as a DSL router. It provides an address for your computer, and is responsible for all communication with the Internet. As far as most users are concerned, the only difference is whether you're plugging a phone cord or a coaxial cable into it. From a technological point of view, however, cable and DSL are as different as apples and oranges. Knowing the pros and cons of each, it's up to you to decide which to pick. Either way, you're bound to enjoy the higher access speed.

Decide Between DSL & Cable
If you have the luxury of choosing between DSL and cable Internet access, here are some tips to help you choose the one that's right for you.

Infrastructure and service
Think about the quality of cable and phone service in your area. Have you dealt with these companies in the past? Were they easy to work with? If your phone is constantly cutting out, but your cable reception is perfect, that's a vote for cable. On the other hand, if every week your cable picture turns to snow right in the middle of "The Simpson's" (and if the folks at the cable TV office seem unresponsive to your plight), perhaps their cable
Internet service won't be much better.

The company
Is one company thriving and expanding while the others are struggling to cut costs? This could be an indication of the company's ability to expand its offerings in the future. These days, a technology company can go from "standard cost-cutting measures" to Chapter 11 in a matter of weeks.

Your neighborhood
How many people live in your area, and what are they like? If your area is filled with young professionals living in condominiums, DSL might be a better choice because of its guaranteed bandwidth. However, if the Shady Meadows Retirement Community surrounds your house, it's possible you'll get great cable access. (Except that you'd be surprised at the number of retirement-aged folks who are surfing the Internet these days.)

Company policy
Some cable providers have policies about the "average bandwidth" they will provide to their customers. In effect, this says, "When you, the customer, are no longer getting 1Mbps of bandwidth, we, the cable provider, will install another access point." Not every provider has such a policy (and their policies can change, of course) but it's worth checking out. This can take some of the guesswork out of what your bandwidth would be like with cable. Be sure to ask your provider about this before signing up.

Some Internet providers require you to lease the router or cable modem; others require that you purchase it. Some companies will give you the router or modem free, if you sign up for a year of service. Each company has different guidelines regarding their CPE (customer premises equipment), so be sure to ask questions and make sure you understand all of the options before you sign a contract.

The loopback test
If you're looking at DSL service, the first thing the provider will do is run a loopback test. They'll send data along the phone lines between your home or office and the nearest office of the DSL provider. They measure the time it takes for the signal to get to, and return from, your location. They also measure the attenuation, or degradation, of the signal. These two factors give the DSL provider a good indication of what the maximum throughput would be on your line. If you live a long way away from the DSL office, or if the wires along which the signal travels are old, your maximum throughput may be too low to make DSL worthwhile. When considering a move to DSL, make sure the provider shares the results of this test with you.

Signing Up
After you've decided which type of service to go with, it's time to start the process of actually getting the service. The first step is to check out the available plans. Both DSL and cable are "always on" connections, so the plans normally won't be rated in hours. However, especially with DSL, there are some significantly different plans from which to choose.

DSL tips
Some DSL providers will charge you for throughput. Some companies will offer a choice of bandwidth options on a sliding scale (the more bandwidth, the more money). Other providers offer only one plan to their residential customers. Whether you have one or 100 plans from which to choose, don't consider any plans offering less than 384Kbps. If you can't get 384Kbps at a price you can afford, you're being ripped off. Another company may be able to offer you something better. Secondly, never get a DSL plan that places a limit on the amount of data you can transfer.

Plans that limit the amount of data you transfer work like this: The company offers "unlimited hours" of DSL service. Be wary, though; to the company, this may not mean "unlimited surfing." Somewhere in the fine print, the contract may limit the amount of data that can be transferred to your computer. For example, you may be permitted to download a total of 100MB of data during any single month, but the ISP may levy a surcharge once you exceed that limit. (Remember the 100MB limit includes not only files you explicitly downloaded, but also whatever Web pages and components you viewed, because you have to download them to view them.) One provider permits total throughput of 20GB, but charges $100 for each additional 35GB of throughput. These plans are bad news, because once you start streaming video or downloading music, you'll use up your allocated bandwidth in no time. Then you're stuck rationing your time online, or avoiding sites that are too bandwidth-intensive. This defeats the whole purpose of upgrading to DSL in the first place. So, read the fine print. Your Internet connection should have no limits on time or the amount of data you can transfer.

Cable signup
Signing up for cable is usually simpler. As noted earlier, whatever bandwidth is available in your location is shared by everyone in that area. Because of this, there's no way to guarantee, and thus no easy way to track, how much bandwidth you're using. For residential customers, there is usually only one service plan.

The static IP option
There's one more option to consider, and this one applies to both cable and DSL: Do you want a static or a dynamic IP address? Static IP addresses sometimes cost a few extra dollars per month but, in certain situations, you may decide they're worth the cost.

An IP address is just like a postal address for your computer, except that instead of telling other people where to reach you by mail, it tells other computers how to reach your computer electronically.

Your DSL router or cable modem will reset its connection to the home office every so often and, naturally, whenever you power down and then get back online later. Whenever it does this, if you have a dynamic IP address, your router (or modem) and your computer are assigned new IP addresses. But if you have a static IP address, your router (or modem) and your computer will always keep the same IP address. A static IP address is essential if you want to host a Web page from your computer, or access your computer's data from another location. If you have either of these things in mind, be sure to ask about static IP addresses.

One last thing to note: If you are considering static IP addresses, make sure they are "routable." Some IP addresses (those beginning with "10" or "192.168") are accessible only from within a LAN. If you plan on hosting a Web page and your IP address isn't routable, only other computers in your house (or, if you're using a cable modem, other people in your immediate area) will be able to reach your computer.

Unless your new Internet provider offers free installation, you'll have to face the eternal question of whether to install it yourself or to pay your provider to install it for you. We'll explain what's involved in installing a cable modem or DSL router so you can decide for yourself.


The prerequisites
Regardless of whether you're installing a cable modem or DSL router, you'll need a NIC (network interface card). This card will permit communication between your computer and the modem or router. These can be purchased at any computer store for as little as $20. Some newer computers have NICs built in; check to see if your computer has a NIC by looking for something on the computer that looks like a wider-than-normal telephone jack.

If you don't have a NIC built into your computer, you'll have to install it yourself or have someone install it for you. Installing a NIC is just like installing other computer peripherals, so if you've upgraded your computer in the past, you can probably handle installing a NIC.

Connecting the dots
Once your NIC is installed and working, hooking up your DSL router or cable modem is quite easy. There should be three cords included with your router or modem: a phone cord or coaxial cable, an Ethernet cable, and a power cable. First, connect the phone cord or coaxial cable from a wall jack into your router or modem. Second, plug one end of the Ethernet cable into your router or cable modem, and plug the other end into the NIC in your computer. Third, connect the power cable to the router or modem and plug it into a wall outlet. At this point, the modem or router will connect to the provider's home office, and you should be surfing in a matter of minutes.

Paying for professionals
If you don't want to attempt to install your router or modem yourself, most providers will gladly do it for you. Many will bring a NIC with them, which you can purchase if you don't have your own. They'll install and set up your NIC, hook up your modem or router, and test it to make sure everything works. This all sounds great, but there are two drawbacks. First, your provider will almost certainly charge you to do the installation. Worse, you'll probably miss a day of work, watching endless reruns of "Bewitched" while you wait for the installer to arrive.

Don't Put It Off
Don't wait too long to upgrade to DSL or cable. Each day, Web sites add more bandwidth-intensive content. It won't be long before surfing the Web at less than 384Kbps will be like driving your 1974 Chevy Vega in the Indy 500: You could do it, but who'd really want to try? So, choose DSL or cable, whichever best fits your situation. Install it yourself or have someone do it for you. Whatever you do, upgrade. Once you've experienced the Internet with DSL or cable, you'll never go back to a dial-up connection.

by Adam Erickson
SmartComputing Magazine




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