Posts: 8
Joined: Thu Oct 18, 2012 11:59 pm

My Project - Global PABX to beat the telcos

Fri Oct 19, 2012 12:17 am

Hi folks,

I'm rather new to RPi (less than 2 months) and have suddenly acquired 5 of the things for various projects like media centres etc.

The project I am most pleased with and wish to write about is my PABX which lets family and friends spread across the world speak to each other for free using Asterisk, FreePBX and of course, a Raspberry Pi. I picked up a bunch of cheap (£11!) VoIP phones of ebay to finish it off.

In a nutshell, I have a RPi velcro'd to the underside of my desk (where else to put it?) which runs the above. My sister in Chicago can now call my mother in South Africa, my friend in South Africa can call a Dutch friend of his in Malawi, I could go on with the little network I have built up. All of the above have VoIP phones which are simply extensions. Any chatting between them is 100% free! What's not to like??

I further extended the idea to incorporate my wife's businesses and our home number (bye bye Virgin land line). My wife has two incoming numbers (handled by a SIP provider) which will ring on a number of phones including (!) her 3CX softphone on her Android phone. Should none of that work, it reroutes the call back out over the normal mobile network and rings her mobile phone like normal.

While the global PABX is not a new idea, the advent of cheap VoIP phones, good internet and of course, the Raspberry Pi, this has now entered the world of home use. No need for even something like a Intel Atom to run it which, for a project like mine, would be overkill and wasteful. (never mind expensive)

The sweet reward of this all was recently on a trip to Chicago my bank cards stopped working due to fraud. Using a free wifi hotspot and 3CX on my mobile, I was able to call my bank in London as if it was a local London call for me. 20 minutes on the phone to the bank cost me 20p. From a mobile. From another country!

A big thanks goes to the RPi makers as well as he who calls himself for making this all idiot proof!


Posts: 1
Joined: Tue Oct 08, 2013 2:55 pm

Re: My Project - Global PABX to beat the telcos

Tue Oct 08, 2013 3:08 pm

How did you integrate 3cx with raspbx? I'm brand new to pi, SIP, and pbx. I've set up my server and can use it with some success from my android tablet using CSipSimple (provided I only use an internal IP address), but when I use 3cx, I receive an error "To use this client your server must be 3cx Phone System Version 11." How do you get around this, or do I need to install a windows server and point that to my rpi?

Posts: 8
Joined: Thu Oct 18, 2012 11:59 pm

Re: My Project - Global PABX to beat the telcos

Tue Oct 08, 2013 7:15 pm

3CX worked without a problem but to be honest, the CSipSimple is a better app. 3CX kept disconnecting and was quite unreliable. I stopped using it.

As for using your public IP - it is possible but you need to scrub up on SIP over NAT. My router is running dd-wrt and milkfish which "sort of" works but still gives me hassles. It's enough to use but not very reliable. I've not had much time to sort it out though.
Another issue you may be having with your public IP / domain name from inside your network is loopback. Make sure your router supports loopback or it will not work. dd-wrt does not by default - you have to enable a rule on the firewall and NAT for it to work.

All in all though, the RPi works well and has saved me a lot of money on my global PABX system which allows my disparate family to communicate (over the phone) for free.

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