If one's business depends on use of a telephone, for goodness sake, get a landline from Verizon, a true landline - not some make-believe landline from a cable carrier. A true landline runs on DC current provided via the copper phone lines. Comcast and Mediacom do not offer true landlines.

Found the info below, but if you are looking for a landline, call Verizon to verify. They will try and make it difficult to purchase. 

• Basic In-State Plan: This plan generally includes unlimited calls within the same state. Pricing for this plan can start at around $20 to $25 per month, depending on the local area.

Unlike cell phones, landlines are not affected by bad weather or power outages, ensuring you can always make necessary calls.

In case of emergencies, having a landline provides more accurate location information to emergency services.

Also, Wi-Fi calling on cell phones was mentioned many times. It is useless if the electric goes out at your home.

So called Network Extenders: Ditto. Useless if the elecrtricity in your home goes out. They need an internet connection.

The tech guy from Verizon made this perfectly clear.