always on

Referring to a continuous Internet connection. Such a connection is always available from the computer through the service providers central office (CO) or headend and to the Internet. Therefore, there are no dial-up delays such as those experienced when using a conventional modem to establish a circuit-switched connection to the Internet over the public switched telephone network (PSTN). The term generally is used to describe xDSL or cable modem services. See also cable modem, circuit-switched, CO, headend, Internet, modem, PSTN, and xDSL.