How Does Dial-up Internet Work?

Dial-up Internet access uses the telephone network to connect a computer directly to an Internet-service provider. A modem in the computer is used to process incoming and outgoing information.

Dial-up Internet was used before broadband connections became commonplace in homes. While it has largely been phased out as broadband has been adopted, it is still used in some rural areas and other places to which Internet-service providers feel are too remote and low in population to run broadband cabling.

From the user's end, the only equipment required is a working telephone jack connected to the public telephone network and a computer with either an internal or external modem. An account is also needed with an Internet-service provider. Users initiate contact with the remote host when logging into their accounts. The modem uses "handshake" signals to first initialize the connection, then to make contact with the host and to provide the user's login credentials. This procedure is accompanied by a unique sequence of electronic noises that are instantly recognizable to anyone who has ever used a modem to connect to the Internet. Some Internet-service providers use an intermediate acceleration server to improve the speed of the handshake connection and also the delivery of content from the Internet.