Digital Subscriber Line (DSL)

• Difficulty Level : Easy
• Last Updated : 01 Apr, 2021

Digital Subscriber Line (DSL, originally, digital subscriber loop) is a communication medium, which is used to transfer internet through copper wire telecommunication line. Along with cable internet, DSL is one of the most popular ways ISPs provide broadband internet access. 
 

• Its aim is to maintain the high speed of the internet being transferred.
• If we ask that how we gonna achieve such a thing i.e., both telephone and internet facility, then the answer is by using splitters or DSL filters(shown in the below diagram). Basically, the use splitter is to splits the frequency and make sure that they can’t get interrupted.

Types of DSL – 
 

1. Symmetric DSL – SDSL, splits the upstream and downstream frequencies evenly, providing equal speeds to both uploading and downloading data transfer. This connection may provide 2 Mbps upstream and downstream.it is mostly preferred by small organizations.
2. Asymmetric DSL – ADSL, provides a wider frequency range for downstream transfers, which offers several times faster downstream speeds. an ADSL connection may offer 20 Mbps downstream and 1.5 Mbps upstream, it is because most users download more data than they upload.

Benefits – 
 

• No Additional Wiring – A DSL connection makes use of your existing telephone wiring, so you will not have to pay for expensive upgrades to your phone system.
• Cost-Effective – DSL internet is a very cost-effective method and is best in connectivity
• Availability of DSL modems by the service providers.
• Users can use both telephone lines and the internet at the same time. And it is because the voice is transferred on other frequencies and digital signals are transferred on others.
• Users can choose between different connection speeds and pricing from various providers.

DSL Internet service only works over a limited physical distance and remains unavailable in many areas where the local telephone infrastructure does not support DSL technology. The service is not available everywhere. The connection is faster for receiving data than it is for sending data over the Internet.