How Does DSL Internet Work?

If you’re in the market for internet service, there’s a good chance you’re feeling overwhelmed with options. Internet service providers, or ISPs, love their buzzwords and acronyms, but they can be misleading to the average consumer. Let’s shed some light on DSL internet, often referred to as “high-speed internet,” and see whether it’s the right choice for your home.

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What is DSL?

DSL stands for Digital Subscriber Line and refers to the technology used to send digital signals through telephone lines. Telephone lines have a much higher bandwidth capacity than ordinary voice service requires; DSL tech takes advantage of that extra bandwidth to move data at high speeds without requiring additional infrastructure. There are several variations of DSL technology; for internet access, the most common kind is ADSL, where the “A” stands for asymmetric. This is the type of connection where the download speed is higher than the upload speed, allowing for faster downloads with the same total bandwidth used.

DSL offers several major advantages over the older dial-up tech that it replaced, making it a worthwhile upgrade for those still using older technology who need a little more from their connection, and since it uses standard telephone lines, availability is excellent. Most internet service providers offer a DSL service, often packaged as “high-speed internet.”

The DSL difference

Compared to dial-up, DSL internet is special for a couple of reasons. While DSL and dial-up both connect through phone lines, dial-up ties up the whole line. This means that you can’t use the internet and make phone calls at the same time; additionally, dial-up requires you to connect every time you want to access the internet.

A DSL connection, on the other hand, is always on and, thanks to a special filter installed at the phone jack, the data signals and phone signals don’t interfere with each other. This allows you to use the phone and internet at the same time, and there is no need to connect each time you sit down at your computer: your connection is always active and waiting for you. Don’t underestimate the convenience and saved time of an always-on connection: nobody wants to sit and wait while their modem beeps and boops just to check some email or order a pizza.

The following shows you how to hook up filters to your phone jacks so your DSL will work properly:

How DSL filters work

Source: Earthlink

Off to the races

None of those fancy features are much use if your signal moves at a snail’s pace, so let’s talk about speed. First up, some terminology: internet speeds are measured in bits per second. Modern internet connections move either kilobits or megabits per second; that’s a thousand and a million bits, respectively. These ranges are usually abbreviated as Kbps and Mbps. Something else to note is that advertised speeds almost always refer to download speed; most connections use the asymmetric technology mentioned above, so your upload speeds will be slower. With that out of the way, let’s look at what DSL has to offer compared to the other common internet technologies.


There’s just no way around it: dial-up is slow. Even the slowest DSL connection will be several times faster than dial-up. While dial-up caps at 56 Kbps, most consumer DSL connections range from 256 Kbps up to 20 Mbps; the exact speeds depend on the specific DSL technology used and the tier of the package you purchase (faster speeds are more expensive).


While moving from dial-up to DSL is a big jump, DSL isn’t the fastest horse in the race. Cable connections, which use coaxial cables rather than phone lines, often start at 25 Mbps and can reach download speeds of well over 100 Mbps. The upload speeds are also going to be faster, which helps with things like publishing photos to Facebook.


The new kid on the block, fiber internet gets its name from the fiber-optic cables it uses to deliver data. Fiber internet is fast. The so-called gigabit internet packages, with speeds up to 1 Gbps (that’s 1,000 megabits), use this technology. If fast speeds are important to you, this is where it’s at. Fiber connections are often expensive, but they don’t have to be: Google Fiber has been moving into cities and undercutting the ISPs in the area for several years with their gigabit internet packages. Fiber availability is still pretty poor, though, so check to see if it’s even an option in your area before letting yourself get too excited!

DSL for gaming

Since gaming tends to be pretty demanding on technology, let’s focus on that a bit. Whether a DSL connection is going to meet your gaming needs largely depends on where in on the speed spectrum your package falls. At the upper end (closer to 20 Mbps) you should find the connection to be plenty fast for gaming.

However, the quality of your experience will also depend on the types of games you’re playing. Highly competitive, fast-paced shooters will require a much faster connection than something more relaxed, like a puzzle game. For fans of MMO (massively multiplayer online) games, like World of Warcraft, DSL speeds should be more than enough. Since most of the game is downloaded locally on the computer, the only time you’ll really notice your connection speed is when downloading large updates.

Money matters

Price, of course, will be a major deciding factor for many folks. DSL tends to be a sort of middle-of-the-road option in terms of pricing. Dial-up is the cheapest option, for those on truly tight budgets or who don’t really use internet access much but want to have it just in case. For example, the ISP EarthLink offers dial-up service for $9.95 per month, while its DSL packages start at $14.95 per month. Its cable service starts at $29.95. Prices will vary by location and provider, but this is the general trend.

DSL installation

A technician typically handles DSL internet installation. AT&T, for example, allows you to schedule an appointment when you place your order. If you prefer the DIY approach, though, kits are usually available for a self-install. These kits have step-by-step instructions specific to your service, but the general process involves installing a filter on your phone jack to keep the internet signal from interfering with your phone or fax signals and then hooking your modem up to both that jack and the computer. Again, this is typically all handled by a professional, so if that sentence is causing you anxiety, take a deep breath! The most you need to worry about here is what appointment time is most convenient for you.

Balancing act

In the end, DSL makes for a solid budget internet choice. It strikes a nice balance between the cheapness of dial-up and the speed of cable and fiber, and is definitely light-years ahead of dial-up for almost anything you might do online. If you need the highest bandwidth and speeds available, cable or fiber will be a better choice. For many, though, DSL might just be a perfect fit.

We suggest going with AT&T, Verizon, or CenturyLink.

Do you have experience with DSL internet? Share your thoughts with us in the comments.

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