You will want a couple things. First get yourself some VoIP phones. Yealink is a decent brand. Grand stream Wave is a good option for Android and iOS softphones.
Secondly download a PBX. I recommend Fusion PBX others will recommend 3cx but the main thing is to avoid Asterisk.
Finally get yourself a SIP trunk from a phone provider.
Now cry in pain as you are constantly bombarded with SIP attacks in your home.
Is fusionpbx completely open source? Do you have any further reasons why you would recommend it?
I was looking into asterisk the last couple of days for a new company PBX and need some alternatives to compare against. Asterisk looks also a bit complicated though not impossible
Ah yes that makes sense. I was taken aback by my latest install of freepbx. I feel it wasn’t as aggressive during the Digium days but it definitely left a bad taste in my mouth.
I heard good things about free switch, although it seems like a paradigm change. I’ll have to check it out.
If you don't need external calling you don't need a trunk, it's just for connecting to the outside world. I found [[https://www.asterisk.org/|Asterisk]] was a good place to start. The config is rather involved though, so there are various front ends for it.