FAQ - Computers

DSL Speed - How Fast Is DSL Internet Service

Question: DSL Speed - How Fast Is DSL Internet Service?

Compared to the performance of cable Internet service, DSL speed has historically been slower. However, the speed of DSL Internet is increasing as the technology improves and service providers upgrade their network infrastructure. The exact DSL speed you will enjoy varies depending on several factors. How fast, then, is DSL?

Answer: Service providers advertise DSL speed in terms of bandwidth ratings. Bandwidth numbers advertised for residential DSL service range from 128 Kbps to 3 Mbps (3000 Kbps).

Because these DSL speed ratings vary so widely, its best to check first with your service provider to determine the bandwidth levels associated with your subscription. Many providers offer a choice of DSL services with different bandwidth ratings.

DSL Speed of Downloading and Uploading

Your DSL speed can change depending on how you use the network.

DSL providers often advertise speed of their service using a combination of two bandwidth numbers; for example, "1.5 Mbps / 128 Kbps:"

Residential DSL services often provide higher bandwidth for downloads than for uploads, as most customers spend more time in network downloading activities. These are sometimes called asymmetric DSL (ADSL) services. In ADSL, the first bandwidth number will be much higher than the second as in the example above. With symmetric DSL (SDSL), both numbers will be the same. Many business-class DSL services utilize SDSL, as business customers often spend significant time uploading over their networks.

DSL Speed Differences Between Households

The rated maximum bandwidth of a DSL connection often cannot be reached. Additionally, actual DSL speeds vary between households. Factors affecting DSL speed include:

Short of rewiring their residence, customers can do little about changing these factors. Other factors you can more directly control include:

Cable Modem Speed

Updated: 4-08-09