There are numerous possible reasons why a DSL connection would keep disconnecting, such as an Internet outage in the area, a problem with the password configuration or a modem or Wi-Fi gateway that needs to be reset. Troubleshooting these problems can be difficult, so it is best to ask for support from a designated service provider.
Outages can cause the Internet connection to time out. Sometimes, people may be using an old password and have forgotten they changed it. If this happens, they can always contact their service provider or have the new password sent to their email address.
Modems and Wi-Fi gateways also have to be reset from time to time. This is usually a simple process that requires someone to turn off his or her modem and leave it modem unplugged for a few moments before plugging it back in and turning it on. People with Wi-Fi adapters on their computers may have to re-install them to reset their Wi-Fi connectivity, as well.