I was checking a phone jack, and it said reverse polarity on my tester. I wired it correctly I was thinking, so I plug in a phone and I had a dial tone. I called the Ph.# also, and it rang. If I have a dial tone, then there was no need to call it also correct? I just remember tip & ring so I thought maybe I should call it. I really don't even know what tip & ring is. Anyway I checked another jack and it lighted green correct polarity. Any idea whats going on? Thank you for your help.