Making analog telephone calls? How can we make the Arduino board interact with old, analog telephone, and to make phone calls?

I guess it involves connecting the board to the telephone with some specific cable (how it's called?)

In addition, I assume it will require us to use the telephone low-level dialing protocol (in order to actually interact with the phone and to send commands). Where can I read about it?

Is there a reason to concern about conversation between the digital/serial board and an analogous device?

By the way, I've read that analog telephones have relatively high voltages that can easily damage the board. I'd love to get any information about things like this, related to connecting Arduino to analog telephones, in order to know about such issues and about what to be concerned and to explore.

Thanks a lot!
Buy an external voice modem with a RS-232 connection. Connect it to a RS-232C shield. Use AT commands to dial numbers and pick up calls. Use voice AT commands to transmit or receive audio.

Never attempt to connect the telephone line directly to an Arduino since, yes, you will fry it. The voltage is all wrong in the first place, and goes even higher when the phone line rings.