In my office (i mean it's not mine) has a telephone where connect my room and my boss room, I want to talk something to her, Should I call or go to her room and talk directly?
Face to face is usually best. There's much more nuances to a conversation in person. Just don't waste her time with inconsequentials.
If it's urgent and very minor I would ring rather than waste time if I just needed a quick yes/no answer authorising me to do something or a similar reason and her office was not within a few minutes walk.