In telecommunications, cable Internet is a form of broadband Internet access that uses the cable television infrastructure. Like digital subscriber lines and fiber optic networks, cable Internet bridges the last kilometre or mile from the Internet provider to the subscriber. It is layered on top of the existing cable television network infrastructure; just as DSL uses the existing telephone network. Cable networks and telephone networks are the two predominant forms of residential Internet access. Recently, both have seen increased competition from fiber deployments, wireless, and mobile networks.

 Hardware and bit rates

Broadband cable Internet access requires a cable modem at the customer premises and a CMTS (Cable Modem Termination System) at a cable operator facility (typically a headend or hub location). The two are connected via coaxial cable or, more commonly, a Hybrid Fiber Coaxial plant. While access networks are sometimes referred to as "last-mile" (or "first-mile") technologies, cable Internet systems can typically operate where the distance between the modem and CMTS is up to 100 miles (160 km). If the HFC network is vast, the CMTS can be grouped into hubs for efficient management.

Downstream, which goes toward the user, bit rates can be as much 400 megabits per second for business connections, and one hundred megabits for consumers depending on the country. Upstream, which goes from the user, rates range from 384Kbit/s to more than 20Mbit/s. One downstream channel can handle hundreds of cable modems. As the system grows, the CMTS can be upgraded with more downstream and upstream ports.

Most Data Over Cable Service Interface Specification (DOCSIS) cable modems restrict upload and download rates, with customizable limits. These limits are set in configuration files which are downloaded to the modem using the Trivial File Transfer Protocol, when the modem first establishes a connection to the provider's equipment. Some users have attempted to override the bandwidth cap and gain access to the full bandwidth of the system (often as much as 30 Mbit/s), by uploading their own configuration file to the cable modem - a process called uncapping. Uncapping is almost always a violation of the Terms of Service agreement.

 

 List of prices for Cabling Internet service: