Alex Robar has written a very useful ebook called FreePBX 2.5 Powerful Telephony Solutions that I read through prior to attempting to configure FreePBX and used as a reference manual.
There are a half dozen things that need to be done in order to get incoming and outgoing calls going:
- Configure a trunk - this is the connection to the SIP provider (who actually connects to the phone network.)
- Create extensions - this sets up the connections that endpoints / handsets on the network use to call or receive calls
- Set up outbound rules - this provides the connection between end-points and the trunk.
- Create a "ring group" - this is how to cause incoming calls to ring end-points
- Create inbound rules - this is how to route calls
There are less than a couple of dozen options to set up across all of these functions to get things running. I used a great tutorial from Mark Berry to make sure I had all the critical components set up correctly.
I already knew how to set up an endpoint - I used X-Lite on my PC and on my wife's laptop for testing and Bria on my iPad and iPhone. After that worked, I set up an OBi302 adapter (it converts an analog phone to an IP phone). I set up the OBi with a wireless USB adapter so I could connect it to a phone in the living room for stress testing (my wife uses that phone for long distance and international calls to her sister and mother.)
It worked - I set up incoming calls to ring all of the extensions I set up and also routed calls to ring to my cell phone as well.
Because of some drop outs using the old Dell desktop as a server, I "upgraded" and installed PIAF on my son's old tower PC. It's a 3 GHz dual core box that performs very well after fixing a hard disk problem. Again, it took a couple of hours to install. And again, I had the problem entering the master password (requiring two keystrokes for each character - annoying, that.)
The new PBX is working much better (no dropouts, snappy PIAF/FreePBX interface.)
Now, all the "tuning" to get things set up just right.
So, what's my point in telling you all this? It's just to let you know that it is possible - and not really that hard. I had a little Linux background, which helped. But no telephony background at all, and yet I was still able to pull it off and get something useful out of the effort using Internet resources and some equipment I had laying around.
The point is: if you can think it, you can do it!