Thank you , both of you for your answers. Now I'd like a second opinion on this. I went to the actual comcast/xfinity building to pay this months bill, because they charge for doing it over the phone. I was talking to the women at the and she said that if I want a second modem I have to pay for a whole nother internet service basically. Then I talked to a man who works for comcast over the phone, and told him my plan, that I wanted to buy an after market modem and hook it up. He said I wouldn't have to pay extra unless I bought it from them.
Which is right do you think? I'm guessing the women behind doesn't know what she's talking about but before I buy anything I'd really like a second opinion. Thanks