Dial Up & DSL Line Noise

Dial-up Internet connections access the Internet through a normal telephone line. The modem in your computer dials a number and sends your ISP your user name and password. Because it uses the Internet through the same frequency as your voice, if someone picks up a phone connected to that line, you lose your connection. Similarly, if you have several phones or other devices such as DSL modems or fax machines on that line, they may be creating noise, interfering with your connection.

Like dial-up, DSL accesses the Internet through a normal phone line. Unlike dial-up, DSL does not operate on the same frequencies as other machines like telephones and fax machines. Because of this, you can use your phone line for other devices while simultaneously using it for DSL access. Sometimes, the frequencies used by DSL can interfere with your other devices. This comes through in the form of noise on your line that is audible during phone usage.

The easiest solution to line noise is to use a phone line filter. These filter out the frequencies used by things like DSL modems, resulting in less or eliminated line noise. They are available through many electronics stores, and are often included in your DSL package from your Internet provider. All you need to do is plug them into your phone jacks, then plug your devices into the line filter. However, you can't plug your DSL modem directly into a filter, as doing so strips the line of the frequencies generated by the modem.

Line filters are just one option for clearing up line noise. You can also choose to have your phone line split when it enters your house,leaving one part for your Internet access and the other for your other devices. This dedicates part of your phone line to your Internet access, meaning other devices don't interfere with it, and they can't interfere with your other devices. This line split can be performed by your telephone or Internet company.