I need to Google for a concept but I don't have the specific word handy.
There is a feature of phone systems in which a call in made to some destination, a second call to another destination, the initiating party
-which is different from (1) and (2)- tells the system (PBX, Voip router, IVR board) to bridge the two calls and then it simply disappears from the whole affair.
That arrangement/protocol obviously saves voice channels.
What is the name of that feature??
TIA,
-Ramon F Herrera