Calls coming in as from-internal

Hi

I have started using an SBC as a registrar for Asterisk. So extenion X will register to the SBC which in turn registers it onto my FreePBX box. That works fine and enables me to eventually take the freepbx box off the internet altogether.

BUT - the SBC is at the same time also our “call distributor” so all incoming calls come from it as well sending them simply to the various freepbx boxes. This has always worked fine until we started using that same SBC as the registrar. Because the IP of the SBC is the IP of all registered extensions as well, the incoming call is seen as “from-internal” and tries to dial the DID instead of seeing it as an incoming call and send it to the extension.

Is there a proper way around this? I have figured out a quick and dirty one by simply creating an extension that is identical to the inbound number and forward that to the extension it should have gone to in the first place, was hoping there is a better way of dealing with this.

Any input greatly appreciated.