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Technology Types

DSL (Digital Subscriber Line)

Internet service delivered over traditional copper telephone lines, with speeds that degrade significantly over distance from the provider's central office.

What It Means

DSL was once the dominant broadband technology but is now considered legacy infrastructure. ADSL typically maxes out at 20-50 Mbps download, while VDSL can reach 100 Mbps within about 1,000 feet of the central office. Beyond that distance, speeds drop rapidly. Many major ISPs, including AT&T, have stopped selling new DSL connections and are transitioning customers to fiber or fixed wireless.

Frequently Asked Questions

What does "DSL" mean?

Internet service delivered over traditional copper telephone lines, with speeds that degrade significantly over distance from the provider's central office.

Why does DSL matter for internet quality?

DSL was once the dominant broadband technology but is now considered legacy infrastructure. ADSL typically maxes out at 20-50 Mbps download, while VDSL can reach 100 Mbps within about 1,000 feet of the central office. Beyond that distance, speeds drop rapidly. Many major ISPs, including AT&T, have s...

Related Terms

Fiber Optic (FTTH)
Internet delivered via glass or plastic strands that transmit data as pulses of light, offering the fastest and most reliable residential connections available.
Cable Internet (DOCSIS)
Broadband delivered over coaxial cable TV lines using the DOCSIS protocol, typically offering 100-1,200 Mbps download but significantly slower upload speeds.
Fixed Wireless Access (FWA)
Broadband delivered wirelessly from a cell tower or base station to an antenna at the customer's location, using 4G LTE or 5G signals.
Satellite Internet
Broadband delivered via orbiting satellites, available nearly anywhere but historically limited by high latency and low speeds until the introduction of low-earth orbit constellations.

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About This Data

Definitions based on FCC standards, industry specifications, and federal broadband policy. Speed benchmarks reflect 2024 FCC standards. See our methodology.