We would like to roll out FreePBX to 30+ sites this year. I’ve read about IAX2 trunking to connect sites together… We have a hub/spoke vpn across all sites and plan to install local servers at each site. Is there any way to connect each server to a central box to enable intersite calling? If not would I be looking at creating 30+ IAX trunks on each site so it can talk to the rest? Any direction would be great.
You could connect all the sites to one location but you will probably run into a few issues. One being that you will have a single point of failure that could take down all of your interoffice communnication. The biggest issue will probably be latency and jitter. I would be concered using a VPN between sites unless you have rock solid connections at all of you sites and the latency is low between the sites. Running all the trunks to one site will just amplify the latency issues. The most reliable way to set something like this would be to use an MPLS or Metro E solution but both can be very costly. I would do a lot of testing for latency between the sites to see if it is even feasible before researching how to connect all the sites.
If you can reliably connect all of your sites together then it is a matter of setting up outbound routes and setting up an extension sceam that makes sense.