I am removing a private (POTS) line from my boss' phone. He is going to reuse that POTS line at home. I am assuming i have to out it as a trunk too, correct? i am not really familiar with private lines. I am going to start by nulling the key it's on from his phone, but isn't it also programmed as a rout? and how am i going to figure out which rout it is if i have more than one private line (which i definitely do?) thank you