Cable vs DSL Internet

How Cable and DSL Technologies Differ

Cable internet transmits data over coaxial copper cables using the DOCSIS (Data Over Cable Service Interface Specification) standard. Modern cable networks use DOCSIS 3.1, which supports download speeds up to 10 Gbps and upload speeds up to 1-2 Gbps theoretically, though residential plans typically max out at 1-2 Gbps download. Cable bandwidth is shared among subscribers on a local node, meaning performance can vary based on neighborhood usage.

DSL (Digital Subscriber Line) transmits data over traditional telephone copper wiring. Standard DSL (ADSL) delivers 1-20 Mbps, while VDSL (Very-high-bitrate DSL) can reach 50-100 Mbps. DSL performance degrades significantly with distance from the telephone company's central office or DSLAM equipment. Subscribers more than 2-3 miles from the nearest equipment may get speeds below 5 Mbps, regardless of what plan they purchase.

Side-by-Side Comparison

When Cable Is the Clear Choice

For any household that streams video, plays online games, works from home, or has more than 2-3 connected devices, cable is the significantly better option. The speed difference is not marginal: cable delivers 5-20 times more bandwidth than most DSL connections. A household that struggles with 15 Mbps DSL will experience a transformative improvement with a 200+ Mbps cable connection.

Xfinity offers cable plans starting at $35/month for 75 Mbps, while Spectrum starts at $49.99/month for 300 Mbps with no data caps. Both provide dramatically more bandwidth than any DSL plan at comparable or slightly higher prices.

When DSL Might Still Make Sense

DSL remains relevant in limited scenarios. In rural areas where cable infrastructure does not exist, DSL through the local phone company may be the only wired broadband option. For users with very light internet needs (email, basic browsing, no streaming), a 10-25 Mbps DSL connection may be sufficient at $25-40/month.

DSL also offers a dedicated line rather than shared bandwidth, meaning your speeds are not affected by neighborhood usage. However, this advantage is typically outweighed by DSL's much lower maximum speeds.

Note that most major DSL providers are transitioning to fiber. AT&T has largely stopped selling new DSL connections in favor of its fiber network. Frontier is converting its DSL customers to fiber in many markets. If you are currently on DSL, ask your provider about fiber upgrade availability.

The DSL Sunset: Why It Is Disappearing

DSL technology is approaching the end of its useful life. AT&T formally announced it would stop accepting new DSL orders in 2020. CenturyLink (now Lumen) has shifted focus to fiber. The fundamental limitation is the copper phone line infrastructure, which cannot be upgraded to deliver the speeds modern applications demand without replacing the cables entirely, at which point providers install fiber instead.

If you are currently on DSL, begin exploring alternatives now. Fiber is the best upgrade path, followed by cable. In areas where neither is available, 5G home internet or satellite options like Starlink may provide significant speed improvements over DSL.

Upgrading from DSL to Cable or Fiber

Switching from DSL to cable typically requires a technician visit to install a coaxial cable modem and potentially run new cable to your home if it was never wired for cable TV. The process usually takes 1-2 hours and may have a $35-100 installation fee, though many providers waive this for new customers.

Check what alternatives are available at your address by comparing providers: AT&T vs Spectrum | Xfinity vs AT&T

Find faster internet to replace your DSL:

1-888-788-6413

Understanding the Technology Behind Each Connection

The fundamental technology difference between cable and DSL explains why they perform so differently and helps you understand what to expect from each connection type in practice.

How cable internet works: Cable internet uses coaxial cables originally designed for cable television. The DOCSIS (Data Over Cable Service Interface Specification) standard allows these cables to carry internet data alongside TV signals. Modern DOCSIS 3.1 technology supports download speeds up to 10 Gbps and upload speeds up to 1 Gbps on existing coaxial infrastructure. Cable networks use a shared architecture where homes in a neighborhood connect to a local node, which then connects to the provider's network via fiber. During peak usage hours, this shared architecture can cause slight speed reductions, though modern node splitting has minimized this issue in most areas.

How DSL works: DSL (Digital Subscriber Line) transmits internet data over traditional telephone copper wires. Your connection runs from your home to the nearest DSLAM (Digital Subscriber Line Access Multiplexer), typically located at a telephone company central office or a neighborhood cabinet. Unlike cable, DSL provides a dedicated line from your home to the DSLAM, meaning your speed is not affected by neighbor usage. However, DSL speed degrades significantly with distance from the DSLAM. At 1,000 feet, you might get 100 Mbps on VDSL2. At 5,000 feet, that drops to 25-40 Mbps. Beyond 10,000 feet, expect under 10 Mbps.

When DSL Might Actually Be the Better Choice

Despite cable's speed advantage, there are specific scenarios where DSL provides a better overall experience for certain users. Understanding these situations prevents you from overpaying for speed you do not need.

Light usage households: If you live alone or with one other person and primarily browse the web, check email, and stream video on one device at a time, a 25-50 Mbps DSL connection is functionally identical to cable for your daily experience. Web pages load instantly at any speed above 10 Mbps, and a single HD stream needs only 5 Mbps. Paying $30-40 less per month for DSL when cable's extra speed provides no perceptible benefit is a rational choice.

Areas with old cable infrastructure: In neighborhoods with aging cable infrastructure that has not been upgraded, cable internet can be unreliable with frequent outages and inconsistent speeds. If your local cable network suffers from these issues, a stable DSL connection from a well-maintained telephone network may actually deliver a better day-to-day experience despite lower peak speeds.

Budget priority: DSL plans are consistently $10-30 cheaper per month than comparable cable plans. Over a two-year period, that savings totals $240-720. For budget-conscious households where the extra speed of cable does not translate to a meaningfully better experience, DSL represents sensible frugality. Check our cheap internet plans guide for the most affordable options in each technology category.

The Sunset of DSL: What Existing Users Should Know

Major telephone companies including AT&T, Verizon, and Lumen (CenturyLink) are actively phasing out DSL service in many areas, replacing it with fiber optic or fixed wireless alternatives. This has significant implications for current and prospective DSL customers.

AT&T's DSL phase-out: AT&T stopped accepting new DSL customers in most markets in 2020 and has been migrating existing customers to AT&T Fiber or AT&T Internet Air (fixed wireless) where available. If you are currently on AT&T DSL, expect eventual notification to migrate to an alternative service. The silver lining is that AT&T Fiber provides dramatically better performance at competitive prices.

What DSL phase-out means for you: If DSL is your current or planned internet connection, be aware that future support and investment in DSL infrastructure is declining. Providers are investing in fiber, 5G, and fixed wireless instead. While existing DSL connections will continue working, do not expect speed improvements or infrastructure upgrades. If you are choosing between cable and DSL for a new connection, cable's continued investment and technology roadmap (DOCSIS 4.0) makes it the more future-proof choice. For a broader comparison of all connection types, see our fiber vs cable guide.