Manage your account, check for outages, report service interruptions, and troubleshoot your equipment
How are you going to report a service interruption if you're out? You see this instruction all the time, right?
This is the reason (OK, a reason) why you don't want to get your internet and you phone service from the same provider (looking at you, Comcast). If things go down, it all goes down at once. I learned that lesson a long, long, long time ago. The trick is to spread your failures around.