Question
My phone line is busy?
Answer
Call forwarding (or call diverting), in telephony, is a feature on some telephone networks that allows an incoming call to a called party, which would be otherwise unavailable, to be redirected to a mobile telephone or other telephone number where the desired called party is situated. Usually, the forwarded line rings once, to remind the customer using Call forwarding that the call is being redirected.
— Source: Wikipedia (www.wikipedia.org)