Hello, teachers.
I am reading a play written in 1914, and I am puzzled by a stage direction "ring up". What does this mean? It is used like this:

GRAY. What s your name?
SUMMERS. John Summers.
(Ring up.)
GRAY. Mr. Summers, what is your occupation?
SUMMERS. Electrical engineer.

I am wondering if it means "the spotlight is switched on to a certain person"...