Inexpensive phone service is another byproduct of the Internet. Called VoIP (Voice over Internet Protocol) or Internet Telephony there are a large variety of choices which makes the issue more challenging. There are the front line VoIP providers that focus on business as well as home usage but the savings aren't as substantial. Then there are the two consumer oriented maverick services fighting it out for the bottom dollar. MagicJack and NetTalk. For a couple of dollars a month these two services actually provide good unlimited* national phone service. The pricing is so inexpensive most people don't take them seriously and brush their ads off jokingly. Call quality is good/great, much better than cellular and approaching telecom phone standards.
In short - Pricing is $20/year with a five year commitment or $35/year as you go. The dongle you receive plugs into your computer for initial setup. After that it plugs into a cell phone charger for power, a network cable on your network for Internet access and a phone or a phone cord to the wall jack so all your phones in the house work. After initial setup, your phones will work the same as they always have. Nothing changes, not even your phone number. Your voice messages are even emailed to the email address of your choice so you can listen when away on your smartphone or computer. Both providers offer many other phone features. Check them out.
You do need a good internet connection and it can't be a satellite connection (too much delay/latency). If this is your only phone line, an inexpensive UPS (Uninterruptible Power Supply) should be used on all networking and phone equipment in case of a power-outage emergency. Number porting (using your current phone number) is available for a slight fee. Customer service tends to be sorely lacking if ever needed. Of the two, NetTalk is known to have better customer service (MagicJack only has online chat support). I've had a MagicJack line for over five years and have two of them now. I had one problem long ago and the chat session actually resolved it promptly. After all these years I'm surprised more people haven't taken advantage of this ultra-economical phone service. It's so cheap there's almost nothing to lose really. Let us know if we can help.