DSL Internet in the USA
Digital Subscriber Line Internet In the United States
As one of the older internet connections, DSL internet’s nationwide availability keeps it relevant compared to newer connection types, like cable and fiber. Suburban residents and city-dwellers may shy away from DSL due to preconceptions about it having slower speed. But DSL actually can offer enough speed to satisfy the internet usage of most households. Whether you’re in search of a new internet option or just curious about DSL, here’s a primer to help clarify what DSL is, how it works, and who DSL internet is best for.
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What is DSL internet?
Digital Subscriber Line (DSL) is a “last mile” connection that allows consumers to access the internet by using existing telephone lines.
Tip Box: A “last mile” connection is one that connects your home to the internet from its backbone, which is made up of fiber. DSL, satellite, cable, fiber, and fixed wireless are all “last mile” connections.
DSL is often confused with dial-up internet since both are delivered via the telephone infrastructure. However, DSL is quite different on a technical level. By using higher frequency bands within a telephone line to deliver data, DSL is able to establish a separate, “always on” channel connection, unlike the low-frequency bands that dial-up phone communications travel by. Effectively, this means it will not cut off landline access when in use, which results in a several times faster connection than dial-up.
How does DSL internet work?
Overall, DSL internet works like tin cans on a string: two sender/receivers connected by a wire.
The “can” on the customer’s side is a DSL modem, translating data into webpages and online applications. The string is a telephone cable, which carries data in the form of an electromagnetic signal. The “can” on the internet provider’s side is a decoding device called a digital subscriber line access multiplexer (abbreviated “DSLAM”), designed to route many connections at once and communicate with the internet “backbone.”
Parts of a DSL network
Real-world applications are a bit more complex — there are multiple pieces that make up a DSL connection and at least four through which data travels.
- Copper phone line: Used to send/receive data, copper phone lines are made by twisting two copper wires around one another which decreases interference between the wires and repels electromagnetic interference from outside.
- DSLAM (digital subscriber line access multiplexer): A device that receives, decodes, and transmits electrical signals to many phone lines at once.
- Extender: Also called a “loop extender,” DSL extenders are placed between the DSLAM and subscriber modem to boost the signal within the copper cable, allowing the signal to reach rural customers situated far from the local DSL provider office.
- DSL Filter: A small device that plugs into a phone jack and separates low-frequency phone signal from high-frequency broadband signal.
- DSL Modem: A device installed in a subscriber’s residence, designed to “translate” the electrical signal from the DSL provider into data for a computer or router.
To visualize how data travels via DSL, we picture the telephone cable as a highway. The “lane” for traditional telephone traffic is only 4 Khz wide — but the width of the highway is about 3000 times wider than that, stretching all the way up to about 12,000 Khz
While this is “narrower” than the frequencies possible in a fiber or coaxial broadband connection, it still allows for quite a bit of room to rapidly transmit data.
The anatomy of a telephone cable is very simple compared to other broadband cable technologies. Little has changed since Alexander Graham Bell created the first telephone cable: two copper wires twisted around each other inside a protective coating.
Each household’s DSL connection can vary depending on what type of DSL they have.
Types of DSL
There are 14 different types of DSL service. The two most common are ADSL and VDSL.
ADSL stands for “asynchronous digital subscriber line.” The term “asynchronous” is used because much more bandwidth is allocated for downstream data than upstream data. The ADSL specification has evolved over time, with the latest upgrades called ADSL2 and ADSL2+. While ADSL and ADSL2 use the spectrum band from 2.5 Khz to 1.1 Mhz, ADSL2+ uses twice as much, stretching all the way up to 2.2 Mhz. ADSL can theoretically achieve speeds of up to 24 Mbps down and up to 3.3 Mbps up, but real-world applications are usually a fraction of that — around 10-15 Mbps down and up to 1-3 Mbps up.
VDSL, or “very-high-bit-rate digital subscriber line,” uses advanced modulation and transmission hardware to utilize even higher frequency bands, from 25 Khz all the way up to 12 Mhz. This allows VDSL to achieve speeds of 300 Mbps down, 100 Mbps up. However, this capability quickly lowers in real-world settings, depending on the subscriber’s distance from their ISP’s nearest extender or DSLAM.
Should you get DSL internet?
DSL’s main benefit is its availability. However, the list ends there depending on where you live. For instance, city-dwellers are more likely to have faster connections like cable and fiber available. On the other hand, DSL internet is usually the fastest connection available in suburban and rural areas.
The best way to decide if DSL is right for you is to determine what you use your internet for. For example, online activities that require instant reactions, i.e. video calls and first-person shooter (FPS) games, require an internet connection with low latency: a trait DSL internet does not have. If you have cable and fiber also available to you, it’s best to look into how DSL compares to cable and fiber internet before making your final decision.
Pros and Cons of DSL Broadband
- Widely available via traditional phone infrastructure
- Affordably priced compared to cable, fiber, and fixed wireless
- Direct connection from residence to ISP prevents peak-use slowdown
- Generally provides lower speeds than other broadband technologies
- Connection quality dependent on distance between residence and ISP
- Above-ground cabling susceptible to disruption from storms
Largest DSL Providers
DSL Providers: Availability by State
|Alabama||4,251,699||86.6%||53 DSL Providers|
|Alaska||689,193||92.0%||23 DSL Providers|
|American Samoa||48,732||89.4%||2 DSL Providers|
|Arizona||6,152,163||89.6%||41 DSL Providers|
|Arkansas||2,636,464||87.5%||34 DSL Providers|
|California||36,055,204||93.3%||75 DSL Providers|
|Colorado||4,970,693||93.2%||62 DSL Providers|
|Connecticut||3,480,134||95.8%||25 DSL Providers|
|Delaware||661,317||70.2%||12 DSL Providers|
|District of Columbia||581,144||93.1%||20 DSL Providers|
|Florida||18,585,900||93.4%||50 DSL Providers|
|Georgia||9,401,645||91.5%||66 DSL Providers|
|Guam||158,382||98.4%||2 DSL Providers|
|Hawaii||1,343,315||94.6%||7 DSL Providers|
|Idaho||1,483,417||88.8%||36 DSL Providers|
|Illinois||12,123,941||93.3%||94 DSL Providers|
|Indiana||5,983,708||90.1%||74 DSL Providers|
|Iowa||2,688,958||86.8%||143 DSL Providers|
|Kansas||2,501,211||85.6%||50 DSL Providers|
|Kentucky||3,972,650||89.0%||44 DSL Providers|
|Louisiana||3,974,252||86.5%||33 DSL Providers|
|Maine||1,286,553||95.7%||29 DSL Providers|
|Maryland||4,550,532||76.2%||30 DSL Providers|
|Massachusetts||5,934,373||89.4%||27 DSL Providers|
|Michigan||8,929,505||90.7%||73 DSL Providers|
|Minnesota||5,035,388||92.3%||91 DSL Providers|
|Mississippi||2,615,523||86.7%||36 DSL Providers|
|Missouri||5,505,945||89.7%||74 DSL Providers|
|Montana||933,389||91.0%||30 DSL Providers|
|Nebraska||1,637,935||87.3%||56 DSL Providers|
|Nevada||2,705,546||92.0%||37 DSL Providers|
|New Hampshire||1,275,536||95.1%||22 DSL Providers|
|New Jersey||7,517,003||84.2%||36 DSL Providers|
|New Mexico||1,988,705||92.1%||37 DSL Providers|
|New York||17,794,415||90.9%||64 DSL Providers|
|North Carolina||9,379,776||92.7%||49 DSL Providers|
|North Dakota||471,273||68.0%||34 DSL Providers|
|Northern Mariana Islands||32,087||62.4%||1 DSL Providers|
|Ohio||10,862,060||93.7%||62 DSL Providers|
|Oklahoma||3,324,708||85.6%||55 DSL Providers|
|Oregon||3,639,039||91.1%||68 DSL Providers|
|Pennsylvania||10,560,022||82.0%||70 DSL Providers|
|Puerto Rico||1,801,157||49.8%||5 DSL Providers|
|Rhode Island||846,480||80.6%||13 DSL Providers|
|South Carolina||4,270,361||87.7%||31 DSL Providers|
|South Dakota||622,757||74.0%||38 DSL Providers|
|Tennessee||5,743,706||86.9%||49 DSL Providers|
|Texas||23,631,748||87.6%||115 DSL Providers|
|Utah||2,847,196||95.4%||42 DSL Providers|
|Vermont||614,855||97.4%||18 DSL Providers|
|Virgin Islands||60,492||58.2%||2 DSL Providers|
|Virginia||6,655,500||79.5%||51 DSL Providers|
|Washington||6,611,338||93.4%||55 DSL Providers|
|West Virginia||1,654,087||88.3%||15 DSL Providers|
|Wisconsin||5,269,710||90.7%||100 DSL Providers|
|Wyoming||505,818||85.5%||26 DSL Providers|