A guide to dial–up modems fact sheet | ACMA

A guide to dial–up modems fact sheet

What is a dial-up modem?

A dial-up modem is a device that allows you to gain access to the internet or to another digital service by using a dialled telephone service connection. Dial-up internet access is generally being replaced by ADSL, cable and wireless broadband services. Many internet service providers (ISPs) still offer dial-up internet access for home and business use. Dial-up modems can be purchased from computer and electronic stores and may be integrated into desktop and laptop computers.

Dial-up modems generally come in two physical forms. Internal dial-up modems are installed inside a computer or laptop. External dial-up modems come in their own case and connect to your computer by using a serial or USB port.

It is important when purchasing a dial-up modem that you choose the correct type of dial-up modem for the service you want. Dial-up modems must comply with Australia’s telecommunications safety and technical standards and the device must have an A-Tick compliance label attached on the device.

Please contact the ACMA if you require further information regarding A-Tick compliance labelling.

What is the maximum data rate of a dial-up modem?

Dial-up modems may be capable of data rates up to 56 kilobits per second (kbit/s). The maximum speed available may be limited by other factors such as the type of dial-up modem you have, the quality of the telephone line to your home and other items you have connected to telephone sockets within your home.

How does a dial-up modem work?

The word modem is a contraction of the two words, modulator and demodulator. The modulator function converts the computer’s digital ones and zeros into tone signals and the demodulator function converts the tone signals back into the digital ones and zeros. The public switched telephone network can carry the tone signals in the frequency range used by voice communications and dial-up modems provide an interface between the tone signals over the public switched telephone network and the computer’s ones and zeros.

A dial-up modem also has built-in control functions to establish a connection and to determine the data rate at which tone signals can be sent reliably to the ISP. You will need a fixed line telephone service in order to obtain dial-up internet access.

Who can I contact if I am having trouble with my dial-up modem?

If you are having difficulty with your dial-up modem you should first contact your ISP. ISPs provide and operate the equipment that interface with a dial-up modem and may also provide comprehensive troubleshooting information in the support or FAQ sections on their website. Alternatively, if you believe that your dial-up modem may be faulty, you should contact the vendor or the place of purchase as the dial-up modem may be under warranty.

Please note: this document is intended as a guide only and should not be relied on as legal advice or regarded as a substitute for legal advice in individual cases.


Last updated: 02 May 2017