I set up Asterisk 1.8 for my home phones in the old server once used to a file server. Registered an IP desk phone and IP softphone installed in my iPhone5 to the server, and successfully placed calls to each other, talked to each other, listened to voicemail while unregistered one party.

It was tough to set up the outbound/inbound call configuration to/from the PSTN. I managed to do it, and now I can talk to anybody with my IP phones!