Connecting 4 PBX to one

Hello FreePBX’ers,

I have followed the Connecting Two FreePBX/Asterisk boxes over the internet on the FreePBX Wiki (link) it is describen in this that you can do that but not how. How can i make a master server, as the following configuration of different systems.

System 1 > Extensions 100 till 104
System 2 > Extensions 200 till 204
System 3 > Extensions 300 till 304
System 4 > Extensions 400 till 404

Example: System 1 can call extension 402 when i make a trunk. I want to forward calls to the master server and that server must forward the calls to the destination PBX. How can i do it?

I hope that you can help me.


Why do you want a master server? If you connect each office directly to each of the others, the system will be more reliable and may have lower latency and better voice quality as well. The referenced wiki article tells you exactly what you need to do.

If you are still having trouble, state precisely what is going wrong and supply relevant logs.

We use our PBX in our datacommunication lab at school, here we will simulate a ITSP (provider), all calls must be passed through the ITSP and forwarded to the PBX in the continent. I had made a trunk to the ITSP PBX and set a outgoing call route to it, but it not works. At the moment we have 4 continents with their own PBX, the best option is to route it through the master PBX (ITSP). Excuses me for my English.

Take it one step at a time. Set up the trunk between system 1 and master, but temporarily configure an extension 402 on the master. Confirm that you can call from system 1 to 402. Then, delete 402 and set up the trunk from master to system 4. You shouldn’t have to do anything special on the master, because once the call arrives there, it will be routed the same as if dialed from a local extension.

On the satellite systems, you will send calls for any of the other three over the trunk to the master.

To “simulate a ITSP” in a datacommunication lab at a school, you might want to use a real SIP proxy not a B2BUA like Asterisk.

(just for your master server)

Dicko is right. FreePBX is a PBX not a tandem. Have you studied CLASS features and what the role of a tandem is?

Take a look at Freeswitch or SER and it’s variants. Use this as your ITSP and FreePBX/Asterisk as the clients.

Also building blocks are important. Get one PBX talking to the tandem, document the config then do another. Once you have it working it should scale very well.

After more thinking just keep in mind that at 6 systems your temporal coherence will break down if you don’t use a TARDES instead of a TANDEM

Also, why use 4 boxes at all, try vpn tunnels from other 3 to hq