wiring diagram for sound powered telephone

A demarc or DMARC is a point where the wiring of the telephone company meets up with the customer wiring. It is basically a dividing line between the outside and inside of the structure.

RJ-11 is a standard telephone (non voice over IP)

it is a telephone which is digital and it has a computer inside it

In 1876, Alexander Graham Bell developed his first working telephone. Inside the telephone was a liquid transmitter, a needle, and electrical circuitry.