Update:
I was given an emta with battery backup, for free, and I set out to get it activated with comcast. After spending half an hour speaking to someone who barely spoke english, they tell me it's an additional charge to bring your own modem!! Freaking CROOKS! It's 10 bucks a month to rent the one they provide, or 10 bucks a month service charge to use your own! Unbelievable. Now I have a great emta with a good battery in it, and I can't use it. Good thing it was free. I hate comcast. Before anyone says, "But, if you return theirs and use yours it evens out.....", I need to keep theirs for internet. Stupid all in one gizmo. Comcast really Tee's me off!