A communication medium called Digital Subscriber Line (DSL; formerly known as Digital Subscriber Loop) is used to transmit internet traffic over copper wire telecommunications lines. DSL is one of the most widely used methods by which ISPs offer broadband internet access, along with cable internet.

• Its goal is to keep the data transfer speed at a high level.
• If you're wondering how we'll be able to have both telephone and internet access, the answer is by using splitters or DSL filters (shown in the below diagram). The splitter basically divides the frequency and ensures that they cannot be interrupted.

Different types of DSL

• Equal download and upload speeds are provided by symmetric DSL (SDSL), which evenly divides the upstream and downstream frequencies. 2 Mbps may be available both upstream and downstream on this connection. Small businesses typically prefer it.
• The wider frequency range offered by asymmetric DSL (ADSL) allows for several times faster downstream speeds. Due to the fact that most users download more data than they upload, an ADSL connection may provide 20 Mbps downstream and 1.5 Mbps upstream.

Advantages -

• No Additional Wiring: Since a DSL connection uses your existing telephone wiring, you won't need to invest in pricey phone system upgrades.
• Cost-Effective - DSL internet offers the best connectivity and is a very cost-effective method.
• DSL modems are offered by the service providers.
• Users are able to use the internet and telephone lines simultaneously. And the reason for that is that voice and digital signals use different frequencies to be transmitted.
• Users can select from a range of providers' prices and connection speeds.

Only a small physical distance can be covered by DSL Internet service, and it is frequently not available in places where the local phone infrastructure does not support DSL. Not every location can access the service. When compared to sending data over the Internet, the connection is quicker when receiving data.