I have two or three of everything. Just in case something goes wrong. Like today.
As of 9:00 this morning Comcast disappeared. So did my Internet and my VoiP phone. Not a problem. My business number is a Google Voice number that also rings my cell phone. Phone service? Check. I also have a MiFi card. Internet? Check. (I also have a land line phone which lost long distance only once when a fiber cable was cut 10 years ago).
Just in case I have a backup netbook computer, gmail pulls all my company mail because sometimes the email hosting goes off line and 2 SMTP outgoing mail connections.
It doesn't cost much (if any) money and on a day like today, I'm glad I did.
Oh, I called Comcast and they know they have a problem, but no idea when it will be fixed. Typical Comcast (or should I say XFinity?)