What is ADSL?

You may not have known this but there are actually many types of DSL. Each of these types of DSL utilizes a user’s existing phone to connect them to the Internet. However, each type offers differences in performance.

One type of common DSL service is called ADSL. ADSL stands for “asymmetric digital subscriber line.” Asymmetric digital subscriber line service provides an Internet connection at a high bandwidth over a phone line to a home or business. ADSL provides an “always on” connection and higher speeds than dial-up Internet can provide.

What’s asymmetric about ADSL?

The asymmetric in asymmetric digital subscriber line service refers to the fact that ADSL uses most of its capacity to transmit signal downstream in order to provide a faster download speed. Like other types of DSL, ADSL allows the user to be online and make and receive phone calls – at the same time.

Since more capacity is used to transmit data downstream, very little is sent back from the user’s computer. Because of this, upload speeds will be much slower than download speeds for ADSL users.


Have you heard of VDSL? Are you wondering what the benefits/disadvantages of ADSL vs. VDSL? VDSL stands for “very high speed digital subscriber line.” The main difference between VDSL and ADSL is the speed. VDSL is generally much faster than other forms of DSL, including ADSL. It is often considered a cheaper way to get faster speeds if other high-speed Internet options are unavailable.


Whereas ADSL employs an asymmetric model, SDSL has a symmetric model. SDSL, or symmetric digital subscriber line, offers equal download and upload speeds. ADSL offers significantly slower upload speeds. SDSL allows you to watch online videos and upload home videos at the same rate. ADSL causes photo or video uploads to take much longer.