Carterfone

In 1968, the Federal Communications Commission (FCC) extended this privilege by allowing the Carterfone and other devices to be connected electrically to the AT&T network, as long as they did not cause harm to the system.

When someone on a two-way radio wished to speak to someone on phone, or "landline" (e.g., "Central dispatch, patch me through to McGarrett"), the station operator at the base would dial the telephone number.

In 1968, the Federal Communications Commission extended this privilege by allowing the Carterfone and other devices to be connected electrically to the AT&T network, as long as they did not cause harm to the system.

This ruling, commonly called "the Carterfone decision" (13 F.C.C.2d 420), created the possibility of selling devices that could connect to the phone system using a protective coupler and opened the market to customer-premises equipment.

[3] On April 17, 2015, this petition for rulemaking was dismissed without prejudice by the FCC at the request of Skype's current owner, Microsoft Corporation.