iSymphony supports combining state from multiple PBX connections, in order to see and control Extensions, Queues, Conference Rooms, and Parking Lots across all the connected PBXs at once. This type of installation is more complicated than with a single PBX, and requires additional steps to set up.
It is the responsibility of the Asterisk system administrator to set up bridge trunks between the Asterisk systems in order to allow transferring and originating of calls. iSymphony will assume that the bridge trunks are set up in such a way that the extension number used to dial a device is the same when originating from any of the Asterisk systems.
Your iSymphony license will limit how many active PBX connections you can have at one time. For a combined PBX setup you will need a PBX connection on your license for each PBX you want iSymphony to connect to. See PBX Connections for more information.
Installation with FreePBX
By default, the iSymphony FreePBX module will remove any configuration from iSymphony that it does not know about. This ensures that when extensions, queues, etc. are removed from FreePBX, they will be removed from iSymphony as well. However, if multiple FreePBX installations are connected to the same installation of iSymphony, the FreePBX modules will "fight" with each other, and each module will remove the configuration that the the other modules have set up. To prevent this from happening, you need to login into FreePBX and navigate to Admin->iSymphony V3 and uncheck Clean Unknown Items then Save. You will need to do this on each FreePBX-based system that will be added to iSymphony.
Once you have unchecked the Clean Unknown Items checkbox and saved, you can then proceed to the next steps.
The Clean Unknown Items option is only available in iSymphony FreePBX Module 4.1.4 and above.
In a combined PBX system always remember to uncheck Clean Unknown Items before running Apply Config in FreePBX.
Adding Local PBX Servers
If the PBX you are adding to the iSymphony installation is on the same machine as the iSymphony server, you simply need to setup the Server as you would normally. See Asterisk Server (Vanilla) Installation or FreePBX, Elastix and PBX in a Flash Installation for more information.
Adding Remote PBX Servers
If the PBX you are adding to the combined installation is remote from the iSymphony server, you will need to follow the steps in the Remote Installations section.
If you are using FreePBX, be sure to leave the Server Name field as default in Admin->iSymphony V3 in FreePBX. This is covered in step 5 under Modify The PBX Connection Information->Remote FreePBX Server in the Remote Installations document.