How to raise an asterix?

Question

Asterisk

I have a question. Asterix is ​​nothing more than a program, there are a lot of instructions on how to raise it all, but my question is:
what should this asterix be connected to anyway? so to speak to the provider? not the Internet), namely the communication provider, probably?
So the question is what options are there for this, where all this is connected.
In order for everything to work, where you need to open an account, what settings are needed for all this, what kind of balance, where is the money and is it free. If there is an article about this, please point it out.
And then from reading the manuals for setting up asterix, I conclude that all this works magically and for free ...

Answer 1

By itself, Asterisk is free. That is, all SIP phones, both software and hardware, can communicate with each other when connected to a configured Asterisk server.
If you want them to be able to go to other telephone networks - wired, cellular - you need to organize a SIP / IAX / E1 trunk to any provider or install gateways for analog or GSM networks.