How Does A PBX Work?
The private branch exchange (PBX) is the system most often used by organizations today.
To understand how PBXs work, it is helpful to remember how calls were made before
modern switches came along. Switchboard operators set up call between two phones. A call
completed when the operator established a continuous circuit from the calling party to the
called party. (This is why the phone system is often called a “switched” network.) Think of
it as two tin cans connected by a string.