Busy line interrupt, also known as emergency breakthrough, is a function on
land line
A landline (land line, land-line, main line, home phone, fixed-line, and wireline) is a telephone connection that uses metal wires or optical fiber telephone line for transmission, as distinguished from a mobile cellular network, which uses ...
telephones that allows a caller to interrupt a phone conversation of another caller,
INWARD ASSISTANCE OPERATOR SERVICES
/ref> especially one who does not have call waiting
Call waiting is a telephone service where a subscriber can accept a second incoming telephone call by placing an in-progress call on hold—and may also switch between calls. With some providers it can be combined with additional features such a ...
. It can usually only be initiated by request to the telephone operator.
Much like long distance calling
In telecommunications, a long-distance call (U.S.) or trunk call (also known as a toll call in the U.K. ) is a telephone call made to a location outside a defined local calling area. Long-distance calls are typically charged a higher billing rat ...
before the late 1990s, busy line interrupt is a service provided, for instance, to allow people to contact a family member in the event of an emergency if the receiving party's line is busy and the news cannot wait.
The service is not free and is charged whether or not the calling party can reach the person on the other end (as the phone just might be off the hook for privacy reasons or the line might be connected to the internet
The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a '' network of networks'' that consists of private, pub ...
). For this reason, it is usually only used in cases of emergencies as noted above.
References
External links
US Patent 7133515 - Subscriber control of busy line interrupt and line treatment codesOperator Services & Directory Assistance
Calling features
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