What is DSL? Definition, Speed, Providers, and More

What is DSL, and does anyone even use it anymore? 

Digital Subscriber Line, more commonly known today as DSL, provides broadband Internet through phone wires. It’s an upgraded version of dial-up – it delivers continuous, high-speed Internet access without monopolizing your phone service. 

Like all Internet connection methods, the best way to think about it is simply as a cable carrying a signal. DSL uses existing copper telephone lines to provide Internet access, but in a way that lets you use the Internet while your roommate makes a phone call at the same time, unlike dial-up. The telephone signals are at different frequencies than the Internet data signals, so they don't interfere with each other. Plus, DSL doesn’t make that odd screeching noise when you turn on the computer, like dial-up was (in)famous for. 

In short, DSL is much faster than dial-up connections, providing speeds that can support streaming, gaming, and downloading large files.

Wondering more about DSL and whether it’s a good fit for your Internet needs? Let’s look a little more closely at this technology. 

Definition of DSL: How Does DSL Work?

Officially, DSL stands for Digital Subscriber Line. It’s called that because it transmits info digitally through pre-existing telephone lines that customers (read: subscribers) already had connected to their homes or businesses. 

DSL technology isn’t just a single kind of Internet connection – it encompasses a few different kinds of technology, sometimes summarized as xDSL collectively. 

If you’re not all that interested in the different DSL types, the main thing you need to know is that if you get a DSL broadband connection, you’re probably looking at an asymmetric DSL, which gives you faster download speeds than upload speeds. This is what most households find useful. Now you can skip past this section to where we discuss DSL’s speed and performance.

If you do want all the details, read on below:

The main two kinds of DSL are the Asymmetric Digital Subscriber Line and the Symmetric Digital Subscriber Line.

• Asymmetric Digital Subscriber Line (ADSL) is designed for residential use. Asymmetric DSL offers faster download speeds than upload speeds, which is better for the common user since most of us tend to consume more content than we upload. For example, you may tend to watch more Netflix shows (which requires downloading) versus sending large files to friends or family (which requires uploading).
• Symmetric Digital Subscriber Line (SDSL) is intended for businesses since it provides equal bandwidth for both uploading and downloading. This is because businesses tend to transmit data more equally in both directions, making a symmetric DSL more appropriate.

There are other types of DSL connections, too. For example, carriers offer a service called VDSL, which stands for Very-high-bit-rate Digital Subscriber Line and is basically a faster version of ADSL. There’s also IDSL, which is the ISDN Digital Subscriber Line. This is a hybrid form of Internet connection that combines DSL technology with ISDN (Integrated Services Digital Network) networking standards to deal with some of the distance limitations of other DSL technologies.

Ultimately, the type of DSL technology chosen by an individual or business depends on their specific needs, such as the required speed, the distance from the service provider's facilities, and whether the primary use is for general home Internet activities or more data-intensive business operations.

DSL Speed & Performance

You may be surprised to hear that, despite DSL's tortoise-like reputation, its Internet speeds overlap considerably with cable Internet speeds. A standard DSL connection, such as a residential ADSL line, provides download speeds of around 5 to 120 Mbps, and upload speeds of around 1 to 20 Mbps. For reference, it would take you about six to seven minutes to download a two-hour movie in 1080p HD at 120 Mbps. It would take you 40 minutes to upload that same movie at speeds of 20 Mbps.

By comparison, cable speeds are closer to 10 Mbps to 500 Mbps for download speeds and 5 to 50 Mbps for upload speeds. 

That being said, DSL speeds can vary significantly. You might find that some plans are only in the hundreds of Kbps, while others reach several hundred Mbps. Advanced DSL versions like High-bit-rate DSL (HDSL) and Very-high-bit-rate DSL (VDSL) allow for even faster data transmission rates. 

Speeds depend on factors like the distance from the service provider's central office, with closer subscribers enjoying higher speeds due to reduced signal degradation over copper wire. Speed also depends on your equipment. For example, say you use a wireless router and your computer is located at a distance from the router. If that’s the case, then you can expect slower speeds. The same is true if either your router or computer is on the older side.  

DSL Availability

DSL is at an interesting crossroads right now. It’s one of the most available kinds of Internet service, reaching almost anyone who has access to telephone wires. However, fewer and fewer customers use it, preferring the much faster WiFi options of cable or fiber Internet if they’re available.

But in areas where cable Internet or fiber optic cables haven't reached, like rural and remote regions which are often left behind by other broadband technologies, DSL is a great choice, and often more cost-effective than satellite Internet options. The existing infrastructure of telephone lines means almost everyone can access DSL service, making it a go-to Internet option for many.

DSL Pricing

Pricing for DSL services tends to be more affordable compared to cable Internet and fiber optic Internet, reflecting its position as a middle ground in terms of speed and performance. One estimate puts the average Internet price at around $71 per month. By comparison, the average DSL plan costs around $40 to $70 per month, putting it on the lower end.

Overall, subscribers can often enjoy the benefits of high-speed Internet access without the higher costs associated with cable, fiber, and satellite Internet, though prices can vary based on speed, provider, and location.

DSL Requirements - What You'll Need

To access DSL Internet, you'll need:

• A subscription to a DSL provider in your area – we cover your options below.
• A DSL modem. This acts as a bridge between your digital devices and the DSL service. You can either rent or buy one from your DSL provider, or bring your own.
• A phone line. The physical copper lines will carry the DSL signal to your home or office.
• Optionally, you will probably want a router to distribute your DSL Internet connection wirelessly within your premises. Otherwise, you’re looking at an ethernet cable connection.
• Filters or splitters. These devices separate the frequencies of your phone line, ensuring that phone calls and Internet data do not interfere with each other. 

Not sure where to get that equipment? No need for an emergency trip to Best Buy – your DSL provider will be willing to lease or rent you all those items, and the phone cables should already be hooked up to your home. The only thing you need to take care of is paying your subscription fees. 

DSL Providers

Despite decreasing in popularity in many parts of the country, several ISPs (Internet Service Providers) offer DSL service. These providers vary in terms of plan options, speeds, and coverage, making it crucial for consumers to research and compare to find the best fit for their needs.

Today, you can get a DSL Internet plan from carriers like:

• CenturyLink
• AT&T
• Frontier
• Kinetic by Windstream
• EarthLink
• Verizon
• Ziply Fiber

Here at Navi, we don’t like to tell you which Internet plans are best, simply because the primary factor is who services your area. We would hate to sell you on one DSL provider only for you to discover they’re nowhere near you. 

Instead, we recommend starting by checking your coverage maps to see what carriers service your area. Many times, consumers have just one or two options available, which obviously will influence your choices considerably.

Once you’ve got your shortlist of DSL options, you can take a look at the Internet plan considerations we list below when considering which ISP to choose.

DSL Plan Considerations

When you’re thinking about picking a DSL Internet service plan, you need to look at several factors like price, speed (both download and upload), data caps, contract requirements, and any included extras such as bundled phone service or equipment rentals. 

• Price: DSL offers a range of prices to fit different budgets, often making it a more affordable option compared to fiber or cable Internet – but not always. To pick the best plan, compare monthly costs against the features and speeds offered to ensure you're getting the best value for your money, along with options for cable and fiber in your area.
• Speed (Download and Upload): DSL speeds can vary, with options suitable for everything from basic browsing to more data-intensive tasks like streaming and gaming. Look for a plan that matches your most frequent activities, ensuring fast download speeds for media consumption and adequate upload speeds if you often send large files or video conferences.
• Data Caps: Some DSL plans may have data limits, which can affect how much you can download or stream each month. If you consume a lot of data, look for plans with higher caps or unlimited data to avoid overage charges or throttled speeds.
• Contract Requirements: DSL providers might require you to sign a contract, locking you in for a period. Consider whether a contract fits your needs; some providers offer month-to-month plans that offer greater flexibility but might come at a higher price.
• Included Extras: Many DSL plans come with added benefits like bundled phone service or complimentary equipment rentals, such as modems or routers. Assess the value of these extras, as they can save money and add convenience to your Internet service package.

The right plan should balance your Internet usage patterns with your budget, offering adequate speed for your activities without unnecessary costs.

The Bottom Line

Thinking about a DSL plan? You’re not alone. Despite the prevalence and growing popularity of cable and fiber optic broadband, DSL remains a relevant and valuable option for high-speed Internet, particularly in areas where other broadband technologies are scarce or overly expensive. 

Its use of existing telephone lines for data transmission ensures that DSL will continue to provide a lifeline to the Internet for many, from rural residents to small businesses. 

While it may not offer the highest speeds or be cutting-edge technology, DSL's affordability, availability, and reliability make it a compelling choice for those seeking Internet access without the frills or high costs of newer options.